fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/cleancache.h>
  42 #include <asm/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/ext4.h>
  56
  57 static struct proc_dir_entry *ext4_proc_root;
  58 static struct kset *ext4_kset;
  59 static struct ext4_lazy_init *ext4_li_info;
  60 static struct mutex ext4_li_mtx;
  61 static struct ext4_features *ext4_feat;
  62
  63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                              unsigned long journal_devnum);
  65 static int ext4_commit_super(struct super_block *sb, int sync);
  66 static void ext4_mark_recovery_complete(struct super_block *sb,
  67                                         struct ext4_super_block *es);
  68 static void ext4_clear_journal_err(struct super_block *sb,
  69                                    struct ext4_super_block *es);
  70 static int ext4_sync_fs(struct super_block *sb, int wait);
  71 static const char *ext4_decode_error(struct super_block *sb, int errno,
  72                                      char nbuf[16]);
  73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  75 static int ext4_unfreeze(struct super_block *sb);
  76 static void ext4_write_super(struct super_block *sb);
  77 static int ext4_freeze(struct super_block *sb);
  78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  79                        const char *dev_name, void *data);
  80 static inline int ext2_feature_set_ok(struct super_block *sb);
  81 static inline int ext3_feature_set_ok(struct super_block *sb);
  82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  83 static void ext4_destroy_lazyinit_thread(void);
  84 static void ext4_unregister_li_request(struct super_block *sb);
  85 static void ext4_clear_request_list(void);
  86
  87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88 static struct file_system_type ext2_fs_type = {
  89         .owner          = THIS_MODULE,
  90         .name           = "ext2",
  91         .mount          = ext4_mount,
  92         .kill_sb        = kill_block_super,
  93         .fs_flags       = FS_REQUIRES_DEV,
  94 };
  95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  96 #else
  97 #define IS_EXT2_SB(sb) (0)
  98 #endif
  99
 100
 101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 102 static struct file_system_type ext3_fs_type = {
 103         .owner          = THIS_MODULE,
 104         .name           = "ext3",
 105         .mount          = ext4_mount,
 106         .kill_sb        = kill_block_super,
 107         .fs_flags       = FS_REQUIRES_DEV,
 108 };
 109 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 110 #else
 111 #define IS_EXT3_SB(sb) (0)
 112 #endif
 113
 114 void *ext4_kvmalloc(size_t size, gfp_t flags)
 115 {
 116         void *ret;
 117
 118         ret = kmalloc(size, flags);
 119         if (!ret)
 120                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 121         return ret;
 122 }
 123
 124 void *ext4_kvzalloc(size_t size, gfp_t flags)
 125 {
 126         void *ret;
 127
 128         ret = kzalloc(size, flags);
 129         if (!ret)
 130                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 131         return ret;
 132 }
 133
 134 void ext4_kvfree(void *ptr)
 135 {
 136         if (is_vmalloc_addr(ptr))
 137                 vfree(ptr);
 138         else
 139                 kfree(ptr);
 140
 141 }
 142
 143 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 144                                struct ext4_group_desc *bg)
 145 {
 146         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 147                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 148                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 149 }
 150
 151 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 152                                struct ext4_group_desc *bg)
 153 {
 154         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 155                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 156                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 157 }
 158
 159 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 160                               struct ext4_group_desc *bg)
 161 {
 162         return le32_to_cpu(bg->bg_inode_table_lo) |
 163                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 164                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 165 }
 166
 167 __u32 ext4_free_group_clusters(struct super_block *sb,
 168                                struct ext4_group_desc *bg)
 169 {
 170         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 171                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 172                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 173 }
 174
 175 __u32 ext4_free_inodes_count(struct super_block *sb,
 176                               struct ext4_group_desc *bg)
 177 {
 178         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 179                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 180                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 181 }
 182
 183 __u32 ext4_used_dirs_count(struct super_block *sb,
 184                               struct ext4_group_desc *bg)
 185 {
 186         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 187                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 188                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 189 }
 190
 191 __u32 ext4_itable_unused_count(struct super_block *sb,
 192                               struct ext4_group_desc *bg)
 193 {
 194         return le16_to_cpu(bg->bg_itable_unused_lo) |
 195                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 196                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 197 }
 198
 199 void ext4_block_bitmap_set(struct super_block *sb,
 200                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 201 {
 202         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 203         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 204                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 205 }
 206
 207 void ext4_inode_bitmap_set(struct super_block *sb,
 208                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 209 {
 210         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 211         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 212                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 213 }
 214
 215 void ext4_inode_table_set(struct super_block *sb,
 216                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 217 {
 218         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 219         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 220                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 221 }
 222
 223 void ext4_free_group_clusters_set(struct super_block *sb,
 224                                   struct ext4_group_desc *bg, __u32 count)
 225 {
 226         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 227         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 228                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 229 }
 230
 231 void ext4_free_inodes_set(struct super_block *sb,
 232                           struct ext4_group_desc *bg, __u32 count)
 233 {
 234         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 235         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 236                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 237 }
 238
 239 void ext4_used_dirs_set(struct super_block *sb,
 240                           struct ext4_group_desc *bg, __u32 count)
 241 {
 242         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 243         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 244                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 245 }
 246
 247 void ext4_itable_unused_set(struct super_block *sb,
 248                           struct ext4_group_desc *bg, __u32 count)
 249 {
 250         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 251         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 252                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 253 }
 254
 255
 256 /* Just increment the non-pointer handle value */
 257 static handle_t *ext4_get_nojournal(void)
 258 {
 259         handle_t *handle = current->journal_info;
 260         unsigned long ref_cnt = (unsigned long)handle;
 261
 262         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 263
 264         ref_cnt++;
 265         handle = (handle_t *)ref_cnt;
 266
 267         current->journal_info = handle;
 268         return handle;
 269 }
 270
 271
 272 /* Decrement the non-pointer handle value */
 273 static void ext4_put_nojournal(handle_t *handle)
 274 {
 275         unsigned long ref_cnt = (unsigned long)handle;
 276
 277         BUG_ON(ref_cnt == 0);
 278
 279         ref_cnt--;
 280         handle = (handle_t *)ref_cnt;
 281
 282         current->journal_info = handle;
 283 }
 284
 285 /*
 286  * Wrappers for jbd2_journal_start/end.
 287  *
 288  * The only special thing we need to do here is to make sure that all
 289  * journal_end calls result in the superblock being marked dirty, so
 290  * that sync() will call the filesystem's write_super callback if
 291  * appropriate.
 292  *
 293  * To avoid j_barrier hold in userspace when a user calls freeze(),
 294  * ext4 prevents a new handle from being started by s_frozen, which
 295  * is in an upper layer.
 296  */
 297 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 298 {
 299         journal_t *journal;
 300         handle_t  *handle;
 301
 302         trace_ext4_journal_start(sb, nblocks, _RET_IP_);
 303         if (sb->s_flags & MS_RDONLY)
 304                 return ERR_PTR(-EROFS);
 305
 306         journal = EXT4_SB(sb)->s_journal;
 307         handle = ext4_journal_current_handle();
 308
 309         /*
 310          * If a handle has been started, it should be allowed to
 311          * finish, otherwise deadlock could happen between freeze
 312          * and others(e.g. truncate) due to the restart of the
 313          * journal handle if the filesystem is forzen and active
 314          * handles are not stopped.
 315          */
 316         if (!handle)
 317                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
 318
 319         if (!journal)
 320                 return ext4_get_nojournal();
 321         /*
 322          * Special case here: if the journal has aborted behind our
 323          * backs (eg. EIO in the commit thread), then we still need to
 324          * take the FS itself readonly cleanly.
 325          */
 326         if (is_journal_aborted(journal)) {
 327                 ext4_abort(sb, "Detected aborted journal");
 328                 return ERR_PTR(-EROFS);
 329         }
 330         return jbd2_journal_start(journal, nblocks);
 331 }
 332
 333 /*
 334  * The only special thing we need to do here is to make sure that all
 335  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 336  * that sync() will call the filesystem's write_super callback if
 337  * appropriate.
 338  */
 339 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 340 {
 341         struct super_block *sb;
 342         int err;
 343         int rc;
 344
 345         if (!ext4_handle_valid(handle)) {
 346                 ext4_put_nojournal(handle);
 347                 return 0;
 348         }
 349         sb = handle->h_transaction->t_journal->j_private;
 350         err = handle->h_err;
 351         rc = jbd2_journal_stop(handle);
 352
 353         if (!err)
 354                 err = rc;
 355         if (err)
 356                 __ext4_std_error(sb, where, line, err);
 357         return err;
 358 }
 359
 360 void ext4_journal_abort_handle(const char *caller, unsigned int line,
 361                                const char *err_fn, struct buffer_head *bh,
 362                                handle_t *handle, int err)
 363 {
 364         char nbuf[16];
 365         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 366
 367         BUG_ON(!ext4_handle_valid(handle));
 368
 369         if (bh)
 370                 BUFFER_TRACE(bh, "abort");
 371
 372         if (!handle->h_err)
 373                 handle->h_err = err;
 374
 375         if (is_handle_aborted(handle))
 376                 return;
 377
 378         printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
 379                caller, line, errstr, err_fn);
 380
 381         jbd2_journal_abort_handle(handle);
 382 }
 383
 384 static void __save_error_info(struct super_block *sb, const char *func,
 385                             unsigned int line)
 386 {
 387         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 388
 389         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 390         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 391         es->s_last_error_time = cpu_to_le32(get_seconds());
 392         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 393         es->s_last_error_line = cpu_to_le32(line);
 394         if (!es->s_first_error_time) {
 395                 es->s_first_error_time = es->s_last_error_time;
 396                 strncpy(es->s_first_error_func, func,
 397                         sizeof(es->s_first_error_func));
 398                 es->s_first_error_line = cpu_to_le32(line);
 399                 es->s_first_error_ino = es->s_last_error_ino;
 400                 es->s_first_error_block = es->s_last_error_block;
 401         }
 402         /*
 403          * Start the daily error reporting function if it hasn't been
 404          * started already
 405          */
 406         if (!es->s_error_count)
 407                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 408         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
 409 }
 410
 411 static void save_error_info(struct super_block *sb, const char *func,
 412                             unsigned int line)
 413 {
 414         __save_error_info(sb, func, line);
 415         ext4_commit_super(sb, 1);
 416 }
 417
 418 /*
 419  * The del_gendisk() function uninitializes the disk-specific data
 420  * structures, including the bdi structure, without telling anyone
 421  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 422  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 423  * This is a kludge to prevent these oops until we can put in a proper
 424  * hook in del_gendisk() to inform the VFS and file system layers.
 425  */
 426 static int block_device_ejected(struct super_block *sb)
 427 {
 428         struct inode *bd_inode = sb->s_bdev->bd_inode;
 429         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 430
 431         return bdi->dev == NULL;
 432 }
 433
 434
 435 /* Deal with the reporting of failure conditions on a filesystem such as
 436  * inconsistencies detected or read IO failures.
 437  *
 438  * On ext2, we can store the error state of the filesystem in the
 439  * superblock.  That is not possible on ext4, because we may have other
 440  * write ordering constraints on the superblock which prevent us from
 441  * writing it out straight away; and given that the journal is about to
 442  * be aborted, we can't rely on the current, or future, transactions to
 443  * write out the superblock safely.
 444  *
 445  * We'll just use the jbd2_journal_abort() error code to record an error in
 446  * the journal instead.  On recovery, the journal will complain about
 447  * that error until we've noted it down and cleared it.
 448  */
 449
 450 static void ext4_handle_error(struct super_block *sb)
 451 {
 452         if (sb->s_flags & MS_RDONLY)
 453                 return;
 454
 455         if (!test_opt(sb, ERRORS_CONT)) {
 456                 journal_t *journal = EXT4_SB(sb)->s_journal;
 457
 458                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 459                 if (journal)
 460                         jbd2_journal_abort(journal, -EIO);
 461         }
 462         if (test_opt(sb, ERRORS_RO)) {
 463                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 464                 sb->s_flags |= MS_RDONLY;
 465         }
 466         if (test_opt(sb, ERRORS_PANIC)) {
 467                 if (EXT4_SB(sb)->s_journal &&
 468                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 469                         return;
 470                 panic("EXT4-fs (device %s): panic forced after error\n",
 471                         sb->s_id);
 472         }
 473 }
 474
 475 void __ext4_error(struct super_block *sb, const char *function,
 476                   unsigned int line, const char *fmt, ...)
 477 {
 478         struct va_format vaf;
 479         va_list args;
 480
 481         va_start(args, fmt);
 482         vaf.fmt = fmt;
 483         vaf.va = &args;
 484         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 485                sb->s_id, function, line, current->comm, &vaf);
 486         va_end(args);
 487         save_error_info(sb, function, line);
 488
 489         ext4_handle_error(sb);
 490 }
 491
 492 void ext4_error_inode(struct inode *inode, const char *function,
 493                       unsigned int line, ext4_fsblk_t block,
 494                       const char *fmt, ...)
 495 {
 496         va_list args;
 497         struct va_format vaf;
 498         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 499
 500         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 501         es->s_last_error_block = cpu_to_le64(block);
 502         save_error_info(inode->i_sb, function, line);
 503         va_start(args, fmt);
 504         vaf.fmt = fmt;
 505         vaf.va = &args;
 506         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 507                inode->i_sb->s_id, function, line, inode->i_ino);
 508         if (block)
 509                 printk(KERN_CONT "block %llu: ", block);
 510         printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
 511         va_end(args);
 512
 513         ext4_handle_error(inode->i_sb);
 514 }
 515
 516 void ext4_error_file(struct file *file, const char *function,
 517                      unsigned int line, ext4_fsblk_t block,
 518                      const char *fmt, ...)
 519 {
 520         va_list args;
 521         struct va_format vaf;
 522         struct ext4_super_block *es;
 523         struct inode *inode = file->f_dentry->d_inode;
 524         char pathname[80], *path;
 525
 526         es = EXT4_SB(inode->i_sb)->s_es;
 527         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 528         save_error_info(inode->i_sb, function, line);
 529         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 530         if (IS_ERR(path))
 531                 path = "(unknown)";
 532         printk(KERN_CRIT
 533                "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 534                inode->i_sb->s_id, function, line, inode->i_ino);
 535         if (block)
 536                 printk(KERN_CONT "block %llu: ", block);
 537         va_start(args, fmt);
 538         vaf.fmt = fmt;
 539         vaf.va = &args;
 540         printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
 541         va_end(args);
 542
 543         ext4_handle_error(inode->i_sb);
 544 }
 545
 546 static const char *ext4_decode_error(struct super_block *sb, int errno,
 547                                      char nbuf[16])
 548 {
 549         char *errstr = NULL;
 550
 551         switch (errno) {
 552         case -EIO:
 553                 errstr = "IO failure";
 554                 break;
 555         case -ENOMEM:
 556                 errstr = "Out of memory";
 557                 break;
 558         case -EROFS:
 559                 if (!sb || (EXT4_SB(sb)->s_journal &&
 560                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 561                         errstr = "Journal has aborted";
 562                 else
 563                         errstr = "Readonly filesystem";
 564                 break;
 565         default:
 566                 /* If the caller passed in an extra buffer for unknown
 567                  * errors, textualise them now.  Else we just return
 568                  * NULL. */
 569                 if (nbuf) {
 570                         /* Check for truncated error codes... */
 571                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 572                                 errstr = nbuf;
 573                 }
 574                 break;
 575         }
 576
 577         return errstr;
 578 }
 579
 580 /* __ext4_std_error decodes expected errors from journaling functions
 581  * automatically and invokes the appropriate error response.  */
 582
 583 void __ext4_std_error(struct super_block *sb, const char *function,
 584                       unsigned int line, int errno)
 585 {
 586         char nbuf[16];
 587         const char *errstr;
 588
 589         /* Special case: if the error is EROFS, and we're not already
 590          * inside a transaction, then there's really no point in logging
 591          * an error. */
 592         if (errno == -EROFS && journal_current_handle() == NULL &&
 593             (sb->s_flags & MS_RDONLY))
 594                 return;
 595
 596         errstr = ext4_decode_error(sb, errno, nbuf);
 597         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 598                sb->s_id, function, line, errstr);
 599         save_error_info(sb, function, line);
 600
 601         ext4_handle_error(sb);
 602 }
 603
 604 /*
 605  * ext4_abort is a much stronger failure handler than ext4_error.  The
 606  * abort function may be used to deal with unrecoverable failures such
 607  * as journal IO errors or ENOMEM at a critical moment in log management.
 608  *
 609  * We unconditionally force the filesystem into an ABORT|READONLY state,
 610  * unless the error response on the fs has been set to panic in which
 611  * case we take the easy way out and panic immediately.
 612  */
 613
 614 void __ext4_abort(struct super_block *sb, const char *function,
 615                 unsigned int line, const char *fmt, ...)
 616 {
 617         va_list args;
 618
 619         save_error_info(sb, function, line);
 620         va_start(args, fmt);
 621         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 622                function, line);
 623         vprintk(fmt, args);
 624         printk("\n");
 625         va_end(args);
 626
 627         if ((sb->s_flags & MS_RDONLY) == 0) {
 628                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 629                 sb->s_flags |= MS_RDONLY;
 630                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 631                 if (EXT4_SB(sb)->s_journal)
 632                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 633                 save_error_info(sb, function, line);
 634         }
 635         if (test_opt(sb, ERRORS_PANIC)) {
 636                 if (EXT4_SB(sb)->s_journal &&
 637                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 638                         return;
 639                 panic("EXT4-fs panic from previous error\n");
 640         }
 641 }
 642
 643 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 644 {
 645         struct va_format vaf;
 646         va_list args;
 647
 648         va_start(args, fmt);
 649         vaf.fmt = fmt;
 650         vaf.va = &args;
 651         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 652         va_end(args);
 653 }
 654
 655 void __ext4_warning(struct super_block *sb, const char *function,
 656                     unsigned int line, const char *fmt, ...)
 657 {
 658         struct va_format vaf;
 659         va_list args;
 660
 661         va_start(args, fmt);
 662         vaf.fmt = fmt;
 663         vaf.va = &args;
 664         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 665                sb->s_id, function, line, &vaf);
 666         va_end(args);
 667 }
 668
 669 void __ext4_grp_locked_error(const char *function, unsigned int line,
 670                              struct super_block *sb, ext4_group_t grp,
 671                              unsigned long ino, ext4_fsblk_t block,
 672                              const char *fmt, ...)
 673 __releases(bitlock)
 674 __acquires(bitlock)
 675 {
 676         struct va_format vaf;
 677         va_list args;
 678         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 679
 680         es->s_last_error_ino = cpu_to_le32(ino);
 681         es->s_last_error_block = cpu_to_le64(block);
 682         __save_error_info(sb, function, line);
 683
 684         va_start(args, fmt);
 685
 686         vaf.fmt = fmt;
 687         vaf.va = &args;
 688         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 689                sb->s_id, function, line, grp);
 690         if (ino)
 691                 printk(KERN_CONT "inode %lu: ", ino);
 692         if (block)
 693                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 694         printk(KERN_CONT "%pV\n", &vaf);
 695         va_end(args);
 696
 697         if (test_opt(sb, ERRORS_CONT)) {
 698                 ext4_commit_super(sb, 0);
 699                 return;
 700         }
 701
 702         ext4_unlock_group(sb, grp);
 703         ext4_handle_error(sb);
 704         /*
 705          * We only get here in the ERRORS_RO case; relocking the group
 706          * may be dangerous, but nothing bad will happen since the
 707          * filesystem will have already been marked read/only and the
 708          * journal has been aborted.  We return 1 as a hint to callers
 709          * who might what to use the return value from
 710          * ext4_grp_locked_error() to distinguish between the
 711          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 712          * aggressively from the ext4 function in question, with a
 713          * more appropriate error code.
 714          */
 715         ext4_lock_group(sb, grp);
 716         return;
 717 }
 718
 719 void ext4_update_dynamic_rev(struct super_block *sb)
 720 {
 721         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 722
 723         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 724                 return;
 725
 726         ext4_warning(sb,
 727                      "updating to rev %d because of new feature flag, "
 728                      "running e2fsck is recommended",
 729                      EXT4_DYNAMIC_REV);
 730
 731         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 732         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 733         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 734         /* leave es->s_feature_*compat flags alone */
 735         /* es->s_uuid will be set by e2fsck if empty */
 736
 737         /*
 738          * The rest of the superblock fields should be zero, and if not it
 739          * means they are likely already in use, so leave them alone.  We
 740          * can leave it up to e2fsck to clean up any inconsistencies there.
 741          */
 742 }
 743
 744 /*
 745  * Open the external journal device
 746  */
 747 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 748 {
 749         struct block_device *bdev;
 750         char b[BDEVNAME_SIZE];
 751
 752         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 753         if (IS_ERR(bdev))
 754                 goto fail;
 755         return bdev;
 756
 757 fail:
 758         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 759                         __bdevname(dev, b), PTR_ERR(bdev));
 760         return NULL;
 761 }
 762
 763 /*
 764  * Release the journal device
 765  */
 766 static int ext4_blkdev_put(struct block_device *bdev)
 767 {
 768         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 769 }
 770
 771 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 772 {
 773         struct block_device *bdev;
 774         int ret = -ENODEV;
 775
 776         bdev = sbi->journal_bdev;
 777         if (bdev) {
 778                 ret = ext4_blkdev_put(bdev);
 779                 sbi->journal_bdev = NULL;
 780         }
 781         return ret;
 782 }
 783
 784 static inline struct inode *orphan_list_entry(struct list_head *l)
 785 {
 786         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 787 }
 788
 789 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 790 {
 791         struct list_head *l;
 792
 793         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 794                  le32_to_cpu(sbi->s_es->s_last_orphan));
 795
 796         printk(KERN_ERR "sb_info orphan list:\n");
 797         list_for_each(l, &sbi->s_orphan) {
 798                 struct inode *inode = orphan_list_entry(l);
 799                 printk(KERN_ERR "  "
 800                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 801                        inode->i_sb->s_id, inode->i_ino, inode,
 802                        inode->i_mode, inode->i_nlink,
 803                        NEXT_ORPHAN(inode));
 804         }
 805 }
 806
 807 static void ext4_put_super(struct super_block *sb)
 808 {
 809         struct ext4_sb_info *sbi = EXT4_SB(sb);
 810         struct ext4_super_block *es = sbi->s_es;
 811         int i, err;
 812
 813         ext4_unregister_li_request(sb);
 814         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 815
 816         flush_workqueue(sbi->dio_unwritten_wq);
 817         destroy_workqueue(sbi->dio_unwritten_wq);
 818
 819         lock_super(sb);
 820         if (sb->s_dirt)
 821                 ext4_commit_super(sb, 1);
 822
 823         if (sbi->s_journal) {
 824                 err = jbd2_journal_destroy(sbi->s_journal);
 825                 sbi->s_journal = NULL;
 826                 if (err < 0)
 827                         ext4_abort(sb, "Couldn't clean up the journal");
 828         }
 829
 830         del_timer_sync(&sbi->s_err_report);
 831         ext4_release_system_zone(sb);
 832         ext4_mb_release(sb);
 833         ext4_ext_release(sb);
 834         ext4_xattr_put_super(sb);
 835
 836         if (!(sb->s_flags & MS_RDONLY)) {
 837                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 838                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 839                 ext4_commit_super(sb, 1);
 840         }
 841         if (sbi->s_proc) {
 842                 remove_proc_entry(sb->s_id, ext4_proc_root);
 843         }
 844         kobject_del(&sbi->s_kobj);
 845
 846         for (i = 0; i < sbi->s_gdb_count; i++)
 847                 brelse(sbi->s_group_desc[i]);
 848         ext4_kvfree(sbi->s_group_desc);
 849         ext4_kvfree(sbi->s_flex_groups);
 850         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 851         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 852         percpu_counter_destroy(&sbi->s_dirs_counter);
 853         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 854         brelse(sbi->s_sbh);
 855 #ifdef CONFIG_QUOTA
 856         for (i = 0; i < MAXQUOTAS; i++)
 857                 kfree(sbi->s_qf_names[i]);
 858 #endif
 859
 860         /* Debugging code just in case the in-memory inode orphan list
 861          * isn't empty.  The on-disk one can be non-empty if we've
 862          * detected an error and taken the fs readonly, but the
 863          * in-memory list had better be clean by this point. */
 864         if (!list_empty(&sbi->s_orphan))
 865                 dump_orphan_list(sb, sbi);
 866         J_ASSERT(list_empty(&sbi->s_orphan));
 867
 868         sync_blockdev(sb->s_bdev);
 869         invalidate_bdev(sb->s_bdev);
 870         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 871                 /*
 872                  * Invalidate the journal device's buffers.  We don't want them
 873                  * floating about in memory - the physical journal device may
 874                  * hotswapped, and it breaks the `ro-after' testing code.
 875                  */
 876                 sync_blockdev(sbi->journal_bdev);
 877                 invalidate_bdev(sbi->journal_bdev);
 878                 ext4_blkdev_remove(sbi);
 879         }
 880         if (sbi->s_mmp_tsk)
 881                 kthread_stop(sbi->s_mmp_tsk);
 882         sb->s_fs_info = NULL;
 883         /*
 884          * Now that we are completely done shutting down the
 885          * superblock, we need to actually destroy the kobject.
 886          */
 887         unlock_super(sb);
 888         kobject_put(&sbi->s_kobj);
 889         wait_for_completion(&sbi->s_kobj_unregister);
 890         kfree(sbi->s_blockgroup_lock);
 891         kfree(sbi);
 892 }
 893
 894 static struct kmem_cache *ext4_inode_cachep;
 895
 896 /*
 897  * Called inside transaction, so use GFP_NOFS
 898  */
 899 static struct inode *ext4_alloc_inode(struct super_block *sb)
 900 {
 901         struct ext4_inode_info *ei;
 902
 903         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 904         if (!ei)
 905                 return NULL;
 906
 907         ei->vfs_inode.i_version = 1;
 908         ei->vfs_inode.i_data.writeback_index = 0;
 909         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 910         INIT_LIST_HEAD(&ei->i_prealloc_list);
 911         spin_lock_init(&ei->i_prealloc_lock);
 912         ei->i_reserved_data_blocks = 0;
 913         ei->i_reserved_meta_blocks = 0;
 914         ei->i_allocated_meta_blocks = 0;
 915         ei->i_da_metadata_calc_len = 0;
 916         ei->i_da_metadata_calc_last_lblock = 0;
 917         spin_lock_init(&(ei->i_block_reservation_lock));
 918 #ifdef CONFIG_QUOTA
 919         ei->i_reserved_quota = 0;
 920 #endif
 921         ei->jinode = NULL;
 922         INIT_LIST_HEAD(&ei->i_completed_io_list);
 923         spin_lock_init(&ei->i_completed_io_lock);
 924         ei->cur_aio_dio = NULL;
 925         ei->i_sync_tid = 0;
 926         ei->i_datasync_tid = 0;
 927         atomic_set(&ei->i_ioend_count, 0);
 928         atomic_set(&ei->i_aiodio_unwritten, 0);
 929
 930         return &ei->vfs_inode;
 931 }
 932
 933 static int ext4_drop_inode(struct inode *inode)
 934 {
 935         int drop = generic_drop_inode(inode);
 936
 937         trace_ext4_drop_inode(inode, drop);
 938         return drop;
 939 }
 940
 941 static void ext4_i_callback(struct rcu_head *head)
 942 {
 943         struct inode *inode = container_of(head, struct inode, i_rcu);
 944         INIT_LIST_HEAD(&inode->i_dentry);
 945         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 946 }
 947
 948 static void ext4_destroy_inode(struct inode *inode)
 949 {
 950         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 951                 ext4_msg(inode->i_sb, KERN_ERR,
 952                          "Inode %lu (%p): orphan list check failed!",
 953                          inode->i_ino, EXT4_I(inode));
 954                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 955                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 956                                 true);
 957                 dump_stack();
 958         }
 959         call_rcu(&inode->i_rcu, ext4_i_callback);
 960 }
 961
 962 static void init_once(void *foo)
 963 {
 964         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 965
 966         INIT_LIST_HEAD(&ei->i_orphan);
 967 #ifdef CONFIG_EXT4_FS_XATTR
 968         init_rwsem(&ei->xattr_sem);
 969 #endif
 970         init_rwsem(&ei->i_data_sem);
 971         inode_init_once(&ei->vfs_inode);
 972 }
 973
 974 static int init_inodecache(void)
 975 {
 976         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 977                                              sizeof(struct ext4_inode_info),
 978                                              0, (SLAB_RECLAIM_ACCOUNT|
 979                                                 SLAB_MEM_SPREAD),
 980                                              init_once);
 981         if (ext4_inode_cachep == NULL)
 982                 return -ENOMEM;
 983         return 0;
 984 }
 985
 986 static void destroy_inodecache(void)
 987 {
 988         kmem_cache_destroy(ext4_inode_cachep);
 989 }
 990
 991 void ext4_clear_inode(struct inode *inode)
 992 {
 993         invalidate_inode_buffers(inode);
 994         end_writeback(inode);
 995         dquot_drop(inode);
 996         ext4_discard_preallocations(inode);
 997         if (EXT4_I(inode)->jinode) {
 998                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 999                                                EXT4_I(inode)->jinode);
1000                 jbd2_free_inode(EXT4_I(inode)->jinode);
1001                 EXT4_I(inode)->jinode = NULL;
1002         }
1003 }
1004
1005 static inline void ext4_show_quota_options(struct seq_file *seq,
1006                                            struct super_block *sb)
1007 {
1008 #if defined(CONFIG_QUOTA)
1009         struct ext4_sb_info *sbi = EXT4_SB(sb);
1010
1011         if (sbi->s_jquota_fmt) {
1012                 char *fmtname = "";
1013
1014                 switch (sbi->s_jquota_fmt) {
1015                 case QFMT_VFS_OLD:
1016                         fmtname = "vfsold";
1017                         break;
1018                 case QFMT_VFS_V0:
1019                         fmtname = "vfsv0";
1020                         break;
1021                 case QFMT_VFS_V1:
1022                         fmtname = "vfsv1";
1023                         break;
1024                 }
1025                 seq_printf(seq, ",jqfmt=%s", fmtname);
1026         }
1027
1028         if (sbi->s_qf_names[USRQUOTA])
1029                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1030
1031         if (sbi->s_qf_names[GRPQUOTA])
1032                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1033
1034         if (test_opt(sb, USRQUOTA))
1035                 seq_puts(seq, ",usrquota");
1036
1037         if (test_opt(sb, GRPQUOTA))
1038                 seq_puts(seq, ",grpquota");
1039 #endif
1040 }
1041
1042 /*
1043  * Show an option if
1044  *  - it's set to a non-default value OR
1045  *  - if the per-sb default is different from the global default
1046  */
1047 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
1048 {
1049         int def_errors;
1050         unsigned long def_mount_opts;
1051         struct super_block *sb = vfs->mnt_sb;
1052         struct ext4_sb_info *sbi = EXT4_SB(sb);
1053         struct ext4_super_block *es = sbi->s_es;
1054
1055         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1056         def_errors     = le16_to_cpu(es->s_errors);
1057
1058         if (sbi->s_sb_block != 1)
1059                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
1060         if (test_opt(sb, MINIX_DF))
1061                 seq_puts(seq, ",minixdf");
1062         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
1063                 seq_puts(seq, ",grpid");
1064         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
1065                 seq_puts(seq, ",nogrpid");
1066         if (sbi->s_resuid != EXT4_DEF_RESUID ||
1067             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
1068                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
1069         }
1070         if (sbi->s_resgid != EXT4_DEF_RESGID ||
1071             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
1072                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
1073         }
1074         if (test_opt(sb, ERRORS_RO)) {
1075                 if (def_errors == EXT4_ERRORS_PANIC ||
1076                     def_errors == EXT4_ERRORS_CONTINUE) {
1077                         seq_puts(seq, ",errors=remount-ro");
1078                 }
1079         }
1080         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1081                 seq_puts(seq, ",errors=continue");
1082         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1083                 seq_puts(seq, ",errors=panic");
1084         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
1085                 seq_puts(seq, ",nouid32");
1086         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
1087                 seq_puts(seq, ",debug");
1088 #ifdef CONFIG_EXT4_FS_XATTR
1089         if (test_opt(sb, XATTR_USER))
1090                 seq_puts(seq, ",user_xattr");
1091         if (!test_opt(sb, XATTR_USER))
1092                 seq_puts(seq, ",nouser_xattr");
1093 #endif
1094 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1095         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1096                 seq_puts(seq, ",acl");
1097         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1098                 seq_puts(seq, ",noacl");
1099 #endif
1100         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1101                 seq_printf(seq, ",commit=%u",
1102                            (unsigned) (sbi->s_commit_interval / HZ));
1103         }
1104         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1105                 seq_printf(seq, ",min_batch_time=%u",
1106                            (unsigned) sbi->s_min_batch_time);
1107         }
1108         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1109                 seq_printf(seq, ",max_batch_time=%u",
1110                            (unsigned) sbi->s_max_batch_time);
1111         }
1112
1113         /*
1114          * We're changing the default of barrier mount option, so
1115          * let's always display its mount state so it's clear what its
1116          * status is.
1117          */
1118         seq_puts(seq, ",barrier=");
1119         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1120         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1121                 seq_puts(seq, ",journal_async_commit");
1122         else if (test_opt(sb, JOURNAL_CHECKSUM))
1123                 seq_puts(seq, ",journal_checksum");
1124         if (test_opt(sb, I_VERSION))
1125                 seq_puts(seq, ",i_version");
1126         if (!test_opt(sb, DELALLOC) &&
1127             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1128                 seq_puts(seq, ",nodelalloc");
1129
1130         if (!test_opt(sb, MBLK_IO_SUBMIT))
1131                 seq_puts(seq, ",nomblk_io_submit");
1132         if (sbi->s_stripe)
1133                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1134         /*
1135          * journal mode get enabled in different ways
1136          * So just print the value even if we didn't specify it
1137          */
1138         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1139                 seq_puts(seq, ",data=journal");
1140         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1141                 seq_puts(seq, ",data=ordered");
1142         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1143                 seq_puts(seq, ",data=writeback");
1144
1145         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1146                 seq_printf(seq, ",inode_readahead_blks=%u",
1147                            sbi->s_inode_readahead_blks);
1148
1149         if (test_opt(sb, DATA_ERR_ABORT))
1150                 seq_puts(seq, ",data_err=abort");
1151
1152         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1153                 seq_puts(seq, ",noauto_da_alloc");
1154
1155         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1156                 seq_puts(seq, ",discard");
1157
1158         if (test_opt(sb, NOLOAD))
1159                 seq_puts(seq, ",norecovery");
1160
1161         if (test_opt(sb, DIOREAD_NOLOCK))
1162                 seq_puts(seq, ",dioread_nolock");
1163
1164         if (test_opt(sb, BLOCK_VALIDITY) &&
1165             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1166                 seq_puts(seq, ",block_validity");
1167
1168         if (!test_opt(sb, INIT_INODE_TABLE))
1169                 seq_puts(seq, ",noinit_itable");
1170         else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
1171                 seq_printf(seq, ",init_itable=%u",
1172                            (unsigned) sbi->s_li_wait_mult);
1173
1174         ext4_show_quota_options(seq, sb);
1175
1176         return 0;
1177 }
1178
1179 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1180                                         u64 ino, u32 generation)
1181 {
1182         struct inode *inode;
1183
1184         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1185                 return ERR_PTR(-ESTALE);
1186         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1187                 return ERR_PTR(-ESTALE);
1188
1189         /* iget isn't really right if the inode is currently unallocated!!
1190          *
1191          * ext4_read_inode will return a bad_inode if the inode had been
1192          * deleted, so we should be safe.
1193          *
1194          * Currently we don't know the generation for parent directory, so
1195          * a generation of 0 means "accept any"
1196          */
1197         inode = ext4_iget_normal(sb, ino);
1198         if (IS_ERR(inode))
1199                 return ERR_CAST(inode);
1200         if (generation && inode->i_generation != generation) {
1201                 iput(inode);
1202                 return ERR_PTR(-ESTALE);
1203         }
1204
1205         return inode;
1206 }
1207
1208 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1209                                         int fh_len, int fh_type)
1210 {
1211         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1212                                     ext4_nfs_get_inode);
1213 }
1214
1215 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1216                                         int fh_len, int fh_type)
1217 {
1218         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1219                                     ext4_nfs_get_inode);
1220 }
1221
1222 /*
1223  * Try to release metadata pages (indirect blocks, directories) which are
1224  * mapped via the block device.  Since these pages could have journal heads
1225  * which would prevent try_to_free_buffers() from freeing them, we must use
1226  * jbd2 layer's try_to_free_buffers() function to release them.
1227  */
1228 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1229                                  gfp_t wait)
1230 {
1231         journal_t *journal = EXT4_SB(sb)->s_journal;
1232
1233         WARN_ON(PageChecked(page));
1234         if (!page_has_buffers(page))
1235                 return 0;
1236         if (journal)
1237                 return jbd2_journal_try_to_free_buffers(journal, page,
1238                                                         wait & ~__GFP_WAIT);
1239         return try_to_free_buffers(page);
1240 }
1241
1242 #ifdef CONFIG_QUOTA
1243 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1244 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1245
1246 static int ext4_write_dquot(struct dquot *dquot);
1247 static int ext4_acquire_dquot(struct dquot *dquot);
1248 static int ext4_release_dquot(struct dquot *dquot);
1249 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1250 static int ext4_write_info(struct super_block *sb, int type);
1251 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1252                          struct path *path);
1253 static int ext4_quota_off(struct super_block *sb, int type);
1254 static int ext4_quota_on_mount(struct super_block *sb, int type);
1255 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1256                                size_t len, loff_t off);
1257 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1258                                 const char *data, size_t len, loff_t off);
1259
1260 static const struct dquot_operations ext4_quota_operations = {
1261         .get_reserved_space = ext4_get_reserved_space,
1262         .write_dquot    = ext4_write_dquot,
1263         .acquire_dquot  = ext4_acquire_dquot,
1264         .release_dquot  = ext4_release_dquot,
1265         .mark_dirty     = ext4_mark_dquot_dirty,
1266         .write_info     = ext4_write_info,
1267         .alloc_dquot    = dquot_alloc,
1268         .destroy_dquot  = dquot_destroy,
1269 };
1270
1271 static const struct quotactl_ops ext4_qctl_operations = {
1272         .quota_on       = ext4_quota_on,
1273         .quota_off      = ext4_quota_off,
1274         .quota_sync     = dquot_quota_sync,
1275         .get_info       = dquot_get_dqinfo,
1276         .set_info       = dquot_set_dqinfo,
1277         .get_dqblk      = dquot_get_dqblk,
1278         .set_dqblk      = dquot_set_dqblk
1279 };
1280 #endif
1281
1282 static const struct super_operations ext4_sops = {
1283         .alloc_inode    = ext4_alloc_inode,
1284         .destroy_inode  = ext4_destroy_inode,
1285         .write_inode    = ext4_write_inode,
1286         .dirty_inode    = ext4_dirty_inode,
1287         .drop_inode     = ext4_drop_inode,
1288         .evict_inode    = ext4_evict_inode,
1289         .put_super      = ext4_put_super,
1290         .sync_fs        = ext4_sync_fs,
1291         .freeze_fs      = ext4_freeze,
1292         .unfreeze_fs    = ext4_unfreeze,
1293         .statfs         = ext4_statfs,
1294         .remount_fs     = ext4_remount,
1295         .show_options   = ext4_show_options,
1296 #ifdef CONFIG_QUOTA
1297         .quota_read     = ext4_quota_read,
1298         .quota_write    = ext4_quota_write,
1299 #endif
1300         .bdev_try_to_free_page = bdev_try_to_free_page,
1301 };
1302
1303 static const struct super_operations ext4_nojournal_sops = {
1304         .alloc_inode    = ext4_alloc_inode,
1305         .destroy_inode  = ext4_destroy_inode,
1306         .write_inode    = ext4_write_inode,
1307         .dirty_inode    = ext4_dirty_inode,
1308         .drop_inode     = ext4_drop_inode,
1309         .evict_inode    = ext4_evict_inode,
1310         .write_super    = ext4_write_super,
1311         .put_super      = ext4_put_super,
1312         .statfs         = ext4_statfs,
1313         .remount_fs     = ext4_remount,
1314         .show_options   = ext4_show_options,
1315 #ifdef CONFIG_QUOTA
1316         .quota_read     = ext4_quota_read,
1317         .quota_write    = ext4_quota_write,
1318 #endif
1319         .bdev_try_to_free_page = bdev_try_to_free_page,
1320 };
1321
1322 static const struct export_operations ext4_export_ops = {
1323         .fh_to_dentry = ext4_fh_to_dentry,
1324         .fh_to_parent = ext4_fh_to_parent,
1325         .get_parent = ext4_get_parent,
1326 };
1327
1328 enum {
1329         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1330         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1331         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1332         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1333         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1334         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1335         Opt_journal_update, Opt_journal_dev,
1336         Opt_journal_checksum, Opt_journal_async_commit,
1337         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1338         Opt_data_err_abort, Opt_data_err_ignore,
1339         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1340         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1341         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1342         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1343         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1344         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1345         Opt_inode_readahead_blks, Opt_journal_ioprio,
1346         Opt_dioread_nolock, Opt_dioread_lock,
1347         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1348 };
1349
1350 static const match_table_t tokens = {
1351         {Opt_bsd_df, "bsddf"},
1352         {Opt_minix_df, "minixdf"},
1353         {Opt_grpid, "grpid"},
1354         {Opt_grpid, "bsdgroups"},
1355         {Opt_nogrpid, "nogrpid"},
1356         {Opt_nogrpid, "sysvgroups"},
1357         {Opt_resgid, "resgid=%u"},
1358         {Opt_resuid, "resuid=%u"},
1359         {Opt_sb, "sb=%u"},
1360         {Opt_err_cont, "errors=continue"},
1361         {Opt_err_panic, "errors=panic"},
1362         {Opt_err_ro, "errors=remount-ro"},
1363         {Opt_nouid32, "nouid32"},
1364         {Opt_debug, "debug"},
1365         {Opt_oldalloc, "oldalloc"},
1366         {Opt_orlov, "orlov"},
1367         {Opt_user_xattr, "user_xattr"},
1368         {Opt_nouser_xattr, "nouser_xattr"},
1369         {Opt_acl, "acl"},
1370         {Opt_noacl, "noacl"},
1371         {Opt_noload, "noload"},
1372         {Opt_noload, "norecovery"},
1373         {Opt_nobh, "nobh"},
1374         {Opt_bh, "bh"},
1375         {Opt_commit, "commit=%u"},
1376         {Opt_min_batch_time, "min_batch_time=%u"},
1377         {Opt_max_batch_time, "max_batch_time=%u"},
1378         {Opt_journal_update, "journal=update"},
1379         {Opt_journal_dev, "journal_dev=%u"},
1380         {Opt_journal_checksum, "journal_checksum"},
1381         {Opt_journal_async_commit, "journal_async_commit"},
1382         {Opt_abort, "abort"},
1383         {Opt_data_journal, "data=journal"},
1384         {Opt_data_ordered, "data=ordered"},
1385         {Opt_data_writeback, "data=writeback"},
1386         {Opt_data_err_abort, "data_err=abort"},
1387         {Opt_data_err_ignore, "data_err=ignore"},
1388         {Opt_offusrjquota, "usrjquota="},
1389         {Opt_usrjquota, "usrjquota=%s"},
1390         {Opt_offgrpjquota, "grpjquota="},
1391         {Opt_grpjquota, "grpjquota=%s"},
1392         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1393         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1394         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1395         {Opt_grpquota, "grpquota"},
1396         {Opt_noquota, "noquota"},
1397         {Opt_quota, "quota"},
1398         {Opt_usrquota, "usrquota"},
1399         {Opt_barrier, "barrier=%u"},
1400         {Opt_barrier, "barrier"},
1401         {Opt_nobarrier, "nobarrier"},
1402         {Opt_i_version, "i_version"},
1403         {Opt_stripe, "stripe=%u"},
1404         {Opt_resize, "resize"},
1405         {Opt_delalloc, "delalloc"},
1406         {Opt_nodelalloc, "nodelalloc"},
1407         {Opt_mblk_io_submit, "mblk_io_submit"},
1408         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1409         {Opt_block_validity, "block_validity"},
1410         {Opt_noblock_validity, "noblock_validity"},
1411         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1412         {Opt_journal_ioprio, "journal_ioprio=%u"},
1413         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1414         {Opt_auto_da_alloc, "auto_da_alloc"},
1415         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1416         {Opt_dioread_nolock, "dioread_nolock"},
1417         {Opt_dioread_lock, "dioread_lock"},
1418         {Opt_discard, "discard"},
1419         {Opt_nodiscard, "nodiscard"},
1420         {Opt_init_itable, "init_itable=%u"},
1421         {Opt_init_itable, "init_itable"},
1422         {Opt_noinit_itable, "noinit_itable"},
1423         {Opt_err, NULL},
1424 };
1425
1426 static ext4_fsblk_t get_sb_block(void **data)
1427 {
1428         ext4_fsblk_t    sb_block;
1429         char            *options = (char *) *data;
1430
1431         if (!options || strncmp(options, "sb=", 3) != 0)
1432                 return 1;       /* Default location */
1433
1434         options += 3;
1435         /* TODO: use simple_strtoll with >32bit ext4 */
1436         sb_block = simple_strtoul(options, &options, 0);
1437         if (*options && *options != ',') {
1438                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1439                        (char *) *data);
1440                 return 1;
1441         }
1442         if (*options == ',')
1443                 options++;
1444         *data = (void *) options;
1445
1446         return sb_block;
1447 }
1448
1449 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1450 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1451         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1452
1453 #ifdef CONFIG_QUOTA
1454 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1455 {
1456         struct ext4_sb_info *sbi = EXT4_SB(sb);
1457         char *qname;
1458
1459         if (sb_any_quota_loaded(sb) &&
1460                 !sbi->s_qf_names[qtype]) {
1461                 ext4_msg(sb, KERN_ERR,
1462                         "Cannot change journaled "
1463                         "quota options when quota turned on");
1464                 return 0;
1465         }
1466         qname = match_strdup(args);
1467         if (!qname) {
1468                 ext4_msg(sb, KERN_ERR,
1469                         "Not enough memory for storing quotafile name");
1470                 return 0;
1471         }
1472         if (sbi->s_qf_names[qtype] &&
1473                 strcmp(sbi->s_qf_names[qtype], qname)) {
1474                 ext4_msg(sb, KERN_ERR,
1475                         "%s quota file already specified", QTYPE2NAME(qtype));
1476                 kfree(qname);
1477                 return 0;
1478         }
1479         sbi->s_qf_names[qtype] = qname;
1480         if (strchr(sbi->s_qf_names[qtype], '/')) {
1481                 ext4_msg(sb, KERN_ERR,
1482                         "quotafile must be on filesystem root");
1483                 kfree(sbi->s_qf_names[qtype]);
1484                 sbi->s_qf_names[qtype] = NULL;
1485                 return 0;
1486         }
1487         set_opt(sb, QUOTA);
1488         return 1;
1489 }
1490
1491 static int clear_qf_name(struct super_block *sb, int qtype)
1492 {
1493
1494         struct ext4_sb_info *sbi = EXT4_SB(sb);
1495
1496         if (sb_any_quota_loaded(sb) &&
1497                 sbi->s_qf_names[qtype]) {
1498                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1499                         " when quota turned on");
1500                 return 0;
1501         }
1502         /*
1503          * The space will be released later when all options are confirmed
1504          * to be correct
1505          */
1506         sbi->s_qf_names[qtype] = NULL;
1507         return 1;
1508 }
1509 #endif
1510
1511 static int parse_options(char *options, struct super_block *sb,
1512                          unsigned long *journal_devnum,
1513                          unsigned int *journal_ioprio,
1514                          ext4_fsblk_t *n_blocks_count, int is_remount)
1515 {
1516         struct ext4_sb_info *sbi = EXT4_SB(sb);
1517         char *p;
1518         substring_t args[MAX_OPT_ARGS];
1519         int data_opt = 0;
1520         int option;
1521 #ifdef CONFIG_QUOTA
1522         int qfmt;
1523 #endif
1524
1525         if (!options)
1526                 return 1;
1527
1528         while ((p = strsep(&options, ",")) != NULL) {
1529                 int token;
1530                 if (!*p)
1531                         continue;
1532
1533                 /*
1534                  * Initialize args struct so we know whether arg was
1535                  * found; some options take optional arguments.
1536                  */
1537                 args[0].to = args[0].from = NULL;
1538                 token = match_token(p, tokens, args);
1539                 switch (token) {
1540                 case Opt_bsd_df:
1541                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1542                         clear_opt(sb, MINIX_DF);
1543                         break;
1544                 case Opt_minix_df:
1545                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1546                         set_opt(sb, MINIX_DF);
1547
1548                         break;
1549                 case Opt_grpid:
1550                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1551                         set_opt(sb, GRPID);
1552
1553                         break;
1554                 case Opt_nogrpid:
1555                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1556                         clear_opt(sb, GRPID);
1557
1558                         break;
1559                 case Opt_resuid:
1560                         if (match_int(&args[0], &option))
1561                                 return 0;
1562                         sbi->s_resuid = option;
1563                         break;
1564                 case Opt_resgid:
1565                         if (match_int(&args[0], &option))
1566                                 return 0;
1567                         sbi->s_resgid = option;
1568                         break;
1569                 case Opt_sb:
1570                         /* handled by get_sb_block() instead of here */
1571                         /* *sb_block = match_int(&args[0]); */
1572                         break;
1573                 case Opt_err_panic:
1574                         clear_opt(sb, ERRORS_CONT);
1575                         clear_opt(sb, ERRORS_RO);
1576                         set_opt(sb, ERRORS_PANIC);
1577                         break;
1578                 case Opt_err_ro:
1579                         clear_opt(sb, ERRORS_CONT);
1580                         clear_opt(sb, ERRORS_PANIC);
1581                         set_opt(sb, ERRORS_RO);
1582                         break;
1583                 case Opt_err_cont:
1584                         clear_opt(sb, ERRORS_RO);
1585                         clear_opt(sb, ERRORS_PANIC);
1586                         set_opt(sb, ERRORS_CONT);
1587                         break;
1588                 case Opt_nouid32:
1589                         set_opt(sb, NO_UID32);
1590                         break;
1591                 case Opt_debug:
1592                         set_opt(sb, DEBUG);
1593                         break;
1594                 case Opt_oldalloc:
1595                         ext4_msg(sb, KERN_WARNING,
1596                                  "Ignoring deprecated oldalloc option");
1597                         break;
1598                 case Opt_orlov:
1599                         ext4_msg(sb, KERN_WARNING,
1600                                  "Ignoring deprecated orlov option");
1601                         break;
1602 #ifdef CONFIG_EXT4_FS_XATTR
1603                 case Opt_user_xattr:
1604                         set_opt(sb, XATTR_USER);
1605                         break;
1606                 case Opt_nouser_xattr:
1607                         clear_opt(sb, XATTR_USER);
1608                         break;
1609 #else
1610                 case Opt_user_xattr:
1611                 case Opt_nouser_xattr:
1612                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1613                         break;
1614 #endif
1615 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1616                 case Opt_acl:
1617                         set_opt(sb, POSIX_ACL);
1618                         break;
1619                 case Opt_noacl:
1620                         clear_opt(sb, POSIX_ACL);
1621                         break;
1622 #else
1623                 case Opt_acl:
1624                 case Opt_noacl:
1625                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1626                         break;
1627 #endif
1628                 case Opt_journal_update:
1629                         /* @@@ FIXME */
1630                         /* Eventually we will want to be able to create
1631                            a journal file here.  For now, only allow the
1632                            user to specify an existing inode to be the
1633                            journal file. */
1634                         if (is_remount) {
1635                                 ext4_msg(sb, KERN_ERR,
1636                                          "Cannot specify journal on remount");
1637                                 return 0;
1638                         }
1639                         set_opt(sb, UPDATE_JOURNAL);
1640                         break;
1641                 case Opt_journal_dev:
1642                         if (is_remount) {
1643                                 ext4_msg(sb, KERN_ERR,
1644                                         "Cannot specify journal on remount");
1645                                 return 0;
1646                         }
1647                         if (match_int(&args[0], &option))
1648                                 return 0;
1649                         *journal_devnum = option;
1650                         break;
1651                 case Opt_journal_checksum:
1652                         set_opt(sb, JOURNAL_CHECKSUM);
1653                         break;
1654                 case Opt_journal_async_commit:
1655                         set_opt(sb, JOURNAL_ASYNC_COMMIT);
1656                         set_opt(sb, JOURNAL_CHECKSUM);
1657                         break;
1658                 case Opt_noload:
1659                         set_opt(sb, NOLOAD);
1660                         break;
1661                 case Opt_commit:
1662                         if (match_int(&args[0], &option))
1663                                 return 0;
1664                         if (option < 0)
1665                                 return 0;
1666                         if (option == 0)
1667                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1668                         sbi->s_commit_interval = HZ * option;
1669                         break;
1670                 case Opt_max_batch_time:
1671                         if (match_int(&args[0], &option))
1672                                 return 0;
1673                         if (option < 0)
1674                                 return 0;
1675                         sbi->s_max_batch_time = option;
1676                         break;
1677                 case Opt_min_batch_time:
1678                         if (match_int(&args[0], &option))
1679                                 return 0;
1680                         if (option < 0)
1681                                 return 0;
1682                         sbi->s_min_batch_time = option;
1683                         break;
1684                 case Opt_data_journal:
1685                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1686                         goto datacheck;
1687                 case Opt_data_ordered:
1688                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1689                         goto datacheck;
1690                 case Opt_data_writeback:
1691                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1692                 datacheck:
1693                         if (is_remount) {
1694                                 if (!sbi->s_journal)
1695                                         ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1696                                 else if (test_opt(sb, DATA_FLAGS) != data_opt) {
1697                                         ext4_msg(sb, KERN_ERR,
1698                                                 "Cannot change data mode on remount");
1699                                         return 0;
1700                                 }
1701                         } else {
1702                                 clear_opt(sb, DATA_FLAGS);
1703                                 sbi->s_mount_opt |= data_opt;
1704                         }
1705                         break;
1706                 case Opt_data_err_abort:
1707                         set_opt(sb, DATA_ERR_ABORT);
1708                         break;
1709                 case Opt_data_err_ignore:
1710                         clear_opt(sb, DATA_ERR_ABORT);
1711                         break;
1712 #ifdef CONFIG_QUOTA
1713                 case Opt_usrjquota:
1714                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1715                                 return 0;
1716                         break;
1717                 case Opt_grpjquota:
1718                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1719                                 return 0;
1720                         break;
1721                 case Opt_offusrjquota:
1722                         if (!clear_qf_name(sb, USRQUOTA))
1723                                 return 0;
1724                         break;
1725                 case Opt_offgrpjquota:
1726                         if (!clear_qf_name(sb, GRPQUOTA))
1727                                 return 0;
1728                         break;
1729
1730                 case Opt_jqfmt_vfsold:
1731                         qfmt = QFMT_VFS_OLD;
1732                         goto set_qf_format;
1733                 case Opt_jqfmt_vfsv0:
1734                         qfmt = QFMT_VFS_V0;
1735                         goto set_qf_format;
1736                 case Opt_jqfmt_vfsv1:
1737                         qfmt = QFMT_VFS_V1;
1738 set_qf_format:
1739                         if (sb_any_quota_loaded(sb) &&
1740                             sbi->s_jquota_fmt != qfmt) {
1741                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1742                                         "journaled quota options when "
1743                                         "quota turned on");
1744                                 return 0;
1745                         }
1746                         sbi->s_jquota_fmt = qfmt;
1747                         break;
1748                 case Opt_quota:
1749                 case Opt_usrquota:
1750                         set_opt(sb, QUOTA);
1751                         set_opt(sb, USRQUOTA);
1752                         break;
1753                 case Opt_grpquota:
1754                         set_opt(sb, QUOTA);
1755                         set_opt(sb, GRPQUOTA);
1756                         break;
1757                 case Opt_noquota:
1758                         if (sb_any_quota_loaded(sb)) {
1759                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1760                                         "options when quota turned on");
1761                                 return 0;
1762                         }
1763                         clear_opt(sb, QUOTA);
1764                         clear_opt(sb, USRQUOTA);
1765                         clear_opt(sb, GRPQUOTA);
1766                         break;
1767 #else
1768                 case Opt_quota:
1769                 case Opt_usrquota:
1770                 case Opt_grpquota:
1771                         ext4_msg(sb, KERN_ERR,
1772                                 "quota options not supported");
1773                         break;
1774                 case Opt_usrjquota:
1775                 case Opt_grpjquota:
1776                 case Opt_offusrjquota:
1777                 case Opt_offgrpjquota:
1778                 case Opt_jqfmt_vfsold:
1779                 case Opt_jqfmt_vfsv0:
1780                 case Opt_jqfmt_vfsv1:
1781                         ext4_msg(sb, KERN_ERR,
1782                                 "journaled quota options not supported");
1783                         break;
1784                 case Opt_noquota:
1785                         break;
1786 #endif
1787                 case Opt_abort:
1788                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1789                         break;
1790                 case Opt_nobarrier:
1791                         clear_opt(sb, BARRIER);
1792                         break;
1793                 case Opt_barrier:
1794                         if (args[0].from) {
1795                                 if (match_int(&args[0], &option))
1796                                         return 0;
1797                         } else
1798                                 option = 1;     /* No argument, default to 1 */
1799                         if (option)
1800                                 set_opt(sb, BARRIER);
1801                         else
1802                                 clear_opt(sb, BARRIER);
1803                         break;
1804                 case Opt_ignore:
1805                         break;
1806                 case Opt_resize:
1807                         if (!is_remount) {
1808                                 ext4_msg(sb, KERN_ERR,
1809                                         "resize option only available "
1810                                         "for remount");
1811                                 return 0;
1812                         }
1813                         if (match_int(&args[0], &option) != 0)
1814                                 return 0;
1815                         *n_blocks_count = option;
1816                         break;
1817                 case Opt_nobh:
1818                         ext4_msg(sb, KERN_WARNING,
1819                                  "Ignoring deprecated nobh option");
1820                         break;
1821                 case Opt_bh:
1822                         ext4_msg(sb, KERN_WARNING,
1823                                  "Ignoring deprecated bh option");
1824                         break;
1825                 case Opt_i_version:
1826                         set_opt(sb, I_VERSION);
1827                         sb->s_flags |= MS_I_VERSION;
1828                         break;
1829                 case Opt_nodelalloc:
1830                         clear_opt(sb, DELALLOC);
1831                         clear_opt2(sb, EXPLICIT_DELALLOC);
1832                         break;
1833                 case Opt_mblk_io_submit:
1834                         set_opt(sb, MBLK_IO_SUBMIT);
1835                         break;
1836                 case Opt_nomblk_io_submit:
1837                         clear_opt(sb, MBLK_IO_SUBMIT);
1838                         break;
1839                 case Opt_stripe:
1840                         if (match_int(&args[0], &option))
1841                                 return 0;
1842                         if (option < 0)
1843                                 return 0;
1844                         sbi->s_stripe = option;
1845                         break;
1846                 case Opt_delalloc:
1847                         set_opt(sb, DELALLOC);
1848                         set_opt2(sb, EXPLICIT_DELALLOC);
1849                         break;
1850                 case Opt_block_validity:
1851                         set_opt(sb, BLOCK_VALIDITY);
1852                         break;
1853                 case Opt_noblock_validity:
1854                         clear_opt(sb, BLOCK_VALIDITY);
1855                         break;
1856                 case Opt_inode_readahead_blks:
1857                         if (match_int(&args[0], &option))
1858                                 return 0;
1859                         if (option < 0 || option > (1 << 30))
1860                                 return 0;
1861                         if (option && !is_power_of_2(option)) {
1862                                 ext4_msg(sb, KERN_ERR,
1863                                          "EXT4-fs: inode_readahead_blks"
1864                                          " must be a power of 2");
1865                                 return 0;
1866                         }
1867                         sbi->s_inode_readahead_blks = option;
1868                         break;
1869                 case Opt_journal_ioprio:
1870                         if (match_int(&args[0], &option))
1871                                 return 0;
1872                         if (option < 0 || option > 7)
1873                                 break;
1874                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1875                                                             option);
1876                         break;
1877                 case Opt_noauto_da_alloc:
1878                         set_opt(sb, NO_AUTO_DA_ALLOC);
1879                         break;
1880                 case Opt_auto_da_alloc:
1881                         if (args[0].from) {
1882                                 if (match_int(&args[0], &option))
1883                                         return 0;
1884                         } else
1885                                 option = 1;     /* No argument, default to 1 */
1886                         if (option)
1887                                 clear_opt(sb, NO_AUTO_DA_ALLOC);
1888                         else
1889                                 set_opt(sb,NO_AUTO_DA_ALLOC);
1890                         break;
1891                 case Opt_discard:
1892                         set_opt(sb, DISCARD);
1893                         break;
1894                 case Opt_nodiscard:
1895                         clear_opt(sb, DISCARD);
1896                         break;
1897                 case Opt_dioread_nolock:
1898                         set_opt(sb, DIOREAD_NOLOCK);
1899                         break;
1900                 case Opt_dioread_lock:
1901                         clear_opt(sb, DIOREAD_NOLOCK);
1902                         break;
1903                 case Opt_init_itable:
1904                         set_opt(sb, INIT_INODE_TABLE);
1905                         if (args[0].from) {
1906                                 if (match_int(&args[0], &option))
1907                                         return 0;
1908                         } else
1909                                 option = EXT4_DEF_LI_WAIT_MULT;
1910                         if (option < 0)
1911                                 return 0;
1912                         sbi->s_li_wait_mult = option;
1913                         break;
1914                 case Opt_noinit_itable:
1915                         clear_opt(sb, INIT_INODE_TABLE);
1916                         break;
1917                 default:
1918                         ext4_msg(sb, KERN_ERR,
1919                                "Unrecognized mount option \"%s\" "
1920                                "or missing value", p);
1921                         return 0;
1922                 }
1923         }
1924 #ifdef CONFIG_QUOTA
1925         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1926                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1927                         clear_opt(sb, USRQUOTA);
1928
1929                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1930                         clear_opt(sb, GRPQUOTA);
1931
1932                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1933                         ext4_msg(sb, KERN_ERR, "old and new quota "
1934                                         "format mixing");
1935                         return 0;
1936                 }
1937
1938                 if (!sbi->s_jquota_fmt) {
1939                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1940                                         "not specified");
1941                         return 0;
1942                 }
1943         }
1944 #endif
1945         if (test_opt(sb, DIOREAD_NOLOCK)) {
1946                 int blocksize =
1947                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1948
1949                 if (blocksize < PAGE_CACHE_SIZE) {
1950                         ext4_msg(sb, KERN_ERR, "can't mount with "
1951                                  "dioread_nolock if block size != PAGE_SIZE");
1952                         return 0;
1953                 }
1954         }
1955         return 1;
1956 }
1957
1958 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1959                             int read_only)
1960 {
1961         struct ext4_sb_info *sbi = EXT4_SB(sb);
1962         int res = 0;
1963
1964         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1965                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1966                          "forcing read-only mode");
1967                 res = MS_RDONLY;
1968         }
1969         if (read_only)
1970                 goto done;
1971         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1972                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1973                          "running e2fsck is recommended");
1974         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1975                 ext4_msg(sb, KERN_WARNING,
1976                          "warning: mounting fs with errors, "
1977                          "running e2fsck is recommended");
1978         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1979                  le16_to_cpu(es->s_mnt_count) >=
1980                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1981                 ext4_msg(sb, KERN_WARNING,
1982                          "warning: maximal mount count reached, "
1983                          "running e2fsck is recommended");
1984         else if (le32_to_cpu(es->s_checkinterval) &&
1985                 (le32_to_cpu(es->s_lastcheck) +
1986                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1987                 ext4_msg(sb, KERN_WARNING,
1988                          "warning: checktime reached, "
1989                          "running e2fsck is recommended");
1990         if (!sbi->s_journal)
1991                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1992         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1993                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1994         le16_add_cpu(&es->s_mnt_count, 1);
1995         es->s_mtime = cpu_to_le32(get_seconds());
1996         ext4_update_dynamic_rev(sb);
1997         if (sbi->s_journal)
1998                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1999
2000         ext4_commit_super(sb, 1);
2001 done:
2002         if (test_opt(sb, DEBUG))
2003                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2004                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2005                         sb->s_blocksize,
2006                         sbi->s_groups_count,
2007                         EXT4_BLOCKS_PER_GROUP(sb),
2008                         EXT4_INODES_PER_GROUP(sb),
2009                         sbi->s_mount_opt, sbi->s_mount_opt2);
2010
2011         cleancache_init_fs(sb);
2012         return res;
2013 }
2014
2015 static int ext4_fill_flex_info(struct super_block *sb)
2016 {
2017         struct ext4_sb_info *sbi = EXT4_SB(sb);
2018         struct ext4_group_desc *gdp = NULL;
2019         ext4_group_t flex_group_count;
2020         ext4_group_t flex_group;
2021         unsigned int groups_per_flex = 0;
2022         size_t size;
2023         int i;
2024
2025         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2026         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2027                 sbi->s_log_groups_per_flex = 0;
2028                 return 1;
2029         }
2030         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
2031
2032         /* We allocate both existing and potentially added groups */
2033         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
2034                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
2035                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
2036         size = flex_group_count * sizeof(struct flex_groups);
2037         sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
2038         if (sbi->s_flex_groups == NULL) {
2039                 ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
2040                          flex_group_count);
2041                 goto failed;
2042         }
2043
2044         for (i = 0; i < sbi->s_groups_count; i++) {
2045                 gdp = ext4_get_group_desc(sb, i, NULL);
2046
2047                 flex_group = ext4_flex_group(sbi, i);
2048                 atomic_add(ext4_free_inodes_count(sb, gdp),
2049                            &sbi->s_flex_groups[flex_group].free_inodes);
2050                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2051                              &sbi->s_flex_groups[flex_group].free_clusters);
2052                 atomic_add(ext4_used_dirs_count(sb, gdp),
2053                            &sbi->s_flex_groups[flex_group].used_dirs);
2054         }
2055
2056         return 1;
2057 failed:
2058         return 0;
2059 }
2060
2061 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2062                             struct ext4_group_desc *gdp)
2063 {
2064         __u16 crc = 0;
2065
2066         if (sbi->s_es->s_feature_ro_compat &
2067             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
2068                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
2069                 __le32 le_group = cpu_to_le32(block_group);
2070
2071                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2072                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2073                 crc = crc16(crc, (__u8 *)gdp, offset);
2074                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
2075                 /* for checksum of struct ext4_group_desc do the rest...*/
2076                 if ((sbi->s_es->s_feature_incompat &
2077                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2078                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
2079                         crc = crc16(crc, (__u8 *)gdp + offset,
2080                                     le16_to_cpu(sbi->s_es->s_desc_size) -
2081                                         offset);
2082         }
2083
2084         return cpu_to_le16(crc);
2085 }
2086
2087 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2088                                 struct ext4_group_desc *gdp)
2089 {
2090         if ((sbi->s_es->s_feature_ro_compat &
2091              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2092             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2093                 return 0;
2094
2095         return 1;
2096 }
2097
2098 /* Called at mount-time, super-block is locked */
2099 static int ext4_check_descriptors(struct super_block *sb,
2100                                   ext4_fsblk_t sb_block,
2101                                   ext4_group_t *first_not_zeroed)
2102 {
2103         struct ext4_sb_info *sbi = EXT4_SB(sb);
2104         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2105         ext4_fsblk_t last_block;
2106         ext4_fsblk_t block_bitmap;
2107         ext4_fsblk_t inode_bitmap;
2108         ext4_fsblk_t inode_table;
2109         int flexbg_flag = 0;
2110         ext4_group_t i, grp = sbi->s_groups_count;
2111
2112         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2113                 flexbg_flag = 1;
2114
2115         ext4_debug("Checking group descriptors");
2116
2117         for (i = 0; i < sbi->s_groups_count; i++) {
2118                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2119
2120                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2121                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2122                 else
2123                         last_block = first_block +
2124                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2125
2126                 if ((grp == sbi->s_groups_count) &&
2127                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2128                         grp = i;
2129
2130                 block_bitmap = ext4_block_bitmap(sb, gdp);
2131                 if (block_bitmap == sb_block) {
2132                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2133                                  "Block bitmap for group %u overlaps "
2134                                  "superblock", i);
2135                 }
2136                 if (block_bitmap < first_block || block_bitmap > last_block) {
2137                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2138                                "Block bitmap for group %u not in group "
2139                                "(block %llu)!", i, block_bitmap);
2140                         return 0;
2141                 }
2142                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2143                 if (inode_bitmap == sb_block) {
2144                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2145                                  "Inode bitmap for group %u overlaps "
2146                                  "superblock", i);
2147                 }
2148                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2149                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2150                                "Inode bitmap for group %u not in group "
2151                                "(block %llu)!", i, inode_bitmap);
2152                         return 0;
2153                 }
2154                 inode_table = ext4_inode_table(sb, gdp);
2155                 if (inode_table == sb_block) {
2156                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2157                                  "Inode table for group %u overlaps "
2158                                  "superblock", i);
2159                 }
2160                 if (inode_table < first_block ||
2161                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2162                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2163                                "Inode table for group %u not in group "
2164                                "(block %llu)!", i, inode_table);
2165                         return 0;
2166                 }
2167                 ext4_lock_group(sb, i);
2168                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2169                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2170                                  "Checksum for group %u failed (%u!=%u)",
2171                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2172                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2173                         if (!(sb->s_flags & MS_RDONLY)) {
2174                                 ext4_unlock_group(sb, i);
2175                                 return 0;
2176                         }
2177                 }
2178                 ext4_unlock_group(sb, i);
2179                 if (!flexbg_flag)
2180                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2181         }
2182         if (NULL != first_not_zeroed)
2183                 *first_not_zeroed = grp;
2184
2185         ext4_free_blocks_count_set(sbi->s_es,
2186                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2187         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2188         return 1;
2189 }
2190
2191 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2192  * the superblock) which were deleted from all directories, but held open by
2193  * a process at the time of a crash.  We walk the list and try to delete these
2194  * inodes at recovery time (only with a read-write filesystem).
2195  *
2196  * In order to keep the orphan inode chain consistent during traversal (in
2197  * case of crash during recovery), we link each inode into the superblock
2198  * orphan list_head and handle it the same way as an inode deletion during
2199  * normal operation (which journals the operations for us).
2200  *
2201  * We only do an iget() and an iput() on each inode, which is very safe if we
2202  * accidentally point at an in-use or already deleted inode.  The worst that
2203  * can happen in this case is that we get a "bit already cleared" message from
2204  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2205  * e2fsck was run on this filesystem, and it must have already done the orphan
2206  * inode cleanup for us, so we can safely abort without any further action.
2207  */
2208 static void ext4_orphan_cleanup(struct super_block *sb,
2209                                 struct ext4_super_block *es)
2210 {
2211         unsigned int s_flags = sb->s_flags;
2212         int nr_orphans = 0, nr_truncates = 0;
2213 #ifdef CONFIG_QUOTA
2214         int i;
2215 #endif
2216         if (!es->s_last_orphan) {
2217                 jbd_debug(4, "no orphan inodes to clean up\n");
2218                 return;
2219         }
2220
2221         if (bdev_read_only(sb->s_bdev)) {
2222                 ext4_msg(sb, KERN_ERR, "write access "
2223                         "unavailable, skipping orphan cleanup");
2224                 return;
2225         }
2226
2227         /* Check if feature set would not allow a r/w mount */
2228         if (!ext4_feature_set_ok(sb, 0)) {
2229                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2230                          "unknown ROCOMPAT features");
2231                 return;
2232         }
2233
2234         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2235                 if (es->s_last_orphan)
2236                         jbd_debug(1, "Errors on filesystem, "
2237                                   "clearing orphan list.\n");
2238                 es->s_last_orphan = 0;
2239                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2240                 return;
2241         }
2242
2243         if (s_flags & MS_RDONLY) {
2244                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2245                 sb->s_flags &= ~MS_RDONLY;
2246         }
2247 #ifdef CONFIG_QUOTA
2248         /* Needed for iput() to work correctly and not trash data */
2249         sb->s_flags |= MS_ACTIVE;
2250         /* Turn on quotas so that they are updated correctly */
2251         for (i = 0; i < MAXQUOTAS; i++) {
2252                 if (EXT4_SB(sb)->s_qf_names[i]) {
2253                         int ret = ext4_quota_on_mount(sb, i);
2254                         if (ret < 0)
2255                                 ext4_msg(sb, KERN_ERR,
2256                                         "Cannot turn on journaled "
2257                                         "quota: error %d", ret);
2258                 }
2259         }
2260 #endif
2261
2262         while (es->s_last_orphan) {
2263                 struct inode *inode;
2264
2265                 /*
2266                  * We may have encountered an error during cleanup; if
2267                  * so, skip the rest.
2268                  */
2269                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2270                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2271                         es->s_last_orphan = 0;
2272                         break;
2273                 }
2274
2275                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2276                 if (IS_ERR(inode)) {
2277                         es->s_last_orphan = 0;
2278                         break;
2279                 }
2280
2281                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2282                 dquot_initialize(inode);
2283                 if (inode->i_nlink) {
2284                         ext4_msg(sb, KERN_DEBUG,
2285                                 "%s: truncating inode %lu to %lld bytes",
2286                                 __func__, inode->i_ino, inode->i_size);
2287                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2288                                   inode->i_ino, inode->i_size);
2289                         mutex_lock(&inode->i_mutex);
2290                         ext4_truncate(inode);
2291                         mutex_unlock(&inode->i_mutex);
2292                         nr_truncates++;
2293                 } else {
2294                         ext4_msg(sb, KERN_DEBUG,
2295                                 "%s: deleting unreferenced inode %lu",
2296                                 __func__, inode->i_ino);
2297                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2298                                   inode->i_ino);
2299                         nr_orphans++;
2300                 }
2301                 iput(inode);  /* The delete magic happens here! */
2302         }
2303
2304 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2305
2306         if (nr_orphans)
2307                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2308                        PLURAL(nr_orphans));
2309         if (nr_truncates)
2310                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2311                        PLURAL(nr_truncates));
2312 #ifdef CONFIG_QUOTA
2313         /* Turn quotas off */
2314         for (i = 0; i < MAXQUOTAS; i++) {
2315                 if (sb_dqopt(sb)->files[i])
2316                         dquot_quota_off(sb, i);
2317         }
2318 #endif
2319         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2320 }
2321
2322 /*
2323  * Maximal extent format file size.
2324  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2325  * extent format containers, within a sector_t, and within i_blocks
2326  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2327  * so that won't be a limiting factor.
2328  *
2329  * However there is other limiting factor. We do store extents in the form
2330  * of starting block and length, hence the resulting length of the extent
2331  * covering maximum file size must fit into on-disk format containers as
2332  * well. Given that length is always by 1 unit bigger than max unit (because
2333  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2334  *
2335  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2336  */
2337 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2338 {
2339         loff_t res;
2340         loff_t upper_limit = MAX_LFS_FILESIZE;
2341
2342         /* small i_blocks in vfs inode? */
2343         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2344                 /*
2345                  * CONFIG_LBDAF is not enabled implies the inode
2346                  * i_block represent total blocks in 512 bytes
2347                  * 32 == size of vfs inode i_blocks * 8
2348                  */
2349                 upper_limit = (1LL << 32) - 1;
2350
2351                 /* total blocks in file system block size */
2352                 upper_limit >>= (blkbits - 9);
2353                 upper_limit <<= blkbits;
2354         }
2355
2356         /*
2357          * 32-bit extent-start container, ee_block. We lower the maxbytes
2358          * by one fs block, so ee_len can cover the extent of maximum file
2359          * size
2360          */
2361         res = (1LL << 32) - 1;
2362         res <<= blkbits;
2363
2364         /* Sanity check against vm- & vfs- imposed limits */
2365         if (res > upper_limit)
2366                 res = upper_limit;
2367
2368         return res;
2369 }
2370
2371 /*
2372  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2373  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2374  * We need to be 1 filesystem block less than the 2^48 sector limit.
2375  */
2376 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2377 {
2378         loff_t res = EXT4_NDIR_BLOCKS;
2379         int meta_blocks;
2380         loff_t upper_limit;
2381         /* This is calculated to be the largest file size for a dense, block
2382          * mapped file such that the file's total number of 512-byte sectors,
2383          * including data and all indirect blocks, does not exceed (2^48 - 1).
2384          *
2385          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2386          * number of 512-byte sectors of the file.
2387          */
2388
2389         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2390                 /*
2391                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2392                  * the inode i_block field represents total file blocks in
2393                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2394                  */
2395                 upper_limit = (1LL << 32) - 1;
2396
2397                 /* total blocks in file system block size */
2398                 upper_limit >>= (bits - 9);
2399
2400         } else {
2401                 /*
2402                  * We use 48 bit ext4_inode i_blocks
2403                  * With EXT4_HUGE_FILE_FL set the i_blocks
2404                  * represent total number of blocks in
2405                  * file system block size
2406                  */
2407                 upper_limit = (1LL << 48) - 1;
2408
2409         }
2410
2411         /* indirect blocks */
2412         meta_blocks = 1;
2413         /* double indirect blocks */
2414         meta_blocks += 1 + (1LL << (bits-2));
2415         /* tripple indirect blocks */
2416         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2417
2418         upper_limit -= meta_blocks;
2419         upper_limit <<= bits;
2420
2421         res += 1LL << (bits-2);
2422         res += 1LL << (2*(bits-2));
2423         res += 1LL << (3*(bits-2));
2424         res <<= bits;
2425         if (res > upper_limit)
2426                 res = upper_limit;
2427
2428         if (res > MAX_LFS_FILESIZE)
2429                 res = MAX_LFS_FILESIZE;
2430
2431         return res;
2432 }
2433
2434 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2435                                    ext4_fsblk_t logical_sb_block, int nr)
2436 {
2437         struct ext4_sb_info *sbi = EXT4_SB(sb);
2438         ext4_group_t bg, first_meta_bg;
2439         int has_super = 0;
2440
2441         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2442
2443         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2444             nr < first_meta_bg)
2445                 return logical_sb_block + nr + 1;
2446         bg = sbi->s_desc_per_block * nr;
2447         if (ext4_bg_has_super(sb, bg))
2448                 has_super = 1;
2449
2450         return (has_super + ext4_group_first_block_no(sb, bg));
2451 }
2452
2453 /**
2454  * ext4_get_stripe_size: Get the stripe size.
2455  * @sbi: In memory super block info
2456  *
2457  * If we have specified it via mount option, then
2458  * use the mount option value. If the value specified at mount time is
2459  * greater than the blocks per group use the super block value.
2460  * If the super block value is greater than blocks per group return 0.
2461  * Allocator needs it be less than blocks per group.
2462  *
2463  */
2464 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2465 {
2466         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2467         unsigned long stripe_width =
2468                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2469         int ret;
2470
2471         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2472                 ret = sbi->s_stripe;
2473         else if (stripe_width <= sbi->s_blocks_per_group)
2474                 ret = stripe_width;
2475         else if (stride <= sbi->s_blocks_per_group)
2476                 ret = stride;
2477         else
2478                 ret = 0;
2479
2480         /*
2481          * If the stripe width is 1, this makes no sense and
2482          * we set it to 0 to turn off stripe handling code.
2483          */
2484         if (ret <= 1)
2485                 ret = 0;
2486
2487         return ret;
2488 }
2489
2490 /* sysfs supprt */
2491
2492 struct ext4_attr {
2493         struct attribute attr;
2494         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2495         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2496                          const char *, size_t);
2497         int offset;
2498 };
2499
2500 static int parse_strtoul(const char *buf,
2501                 unsigned long max, unsigned long *value)
2502 {
2503         char *endp;
2504
2505         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2506         endp = skip_spaces(endp);
2507         if (*endp || *value > max)
2508                 return -EINVAL;
2509
2510         return 0;
2511 }
2512
2513 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2514                                               struct ext4_sb_info *sbi,
2515                                               char *buf)
2516 {
2517         return snprintf(buf, PAGE_SIZE, "%llu\n",
2518                 (s64) EXT4_C2B(sbi,
2519                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2520 }
2521
2522 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2523                                          struct ext4_sb_info *sbi, char *buf)
2524 {
2525         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2526
2527         if (!sb->s_bdev->bd_part)
2528                 return snprintf(buf, PAGE_SIZE, "0\n");
2529         return snprintf(buf, PAGE_SIZE, "%lu\n",
2530                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2531                          sbi->s_sectors_written_start) >> 1);
2532 }
2533
2534 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2535                                           struct ext4_sb_info *sbi, char *buf)
2536 {
2537         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2538
2539         if (!sb->s_bdev->bd_part)
2540                 return snprintf(buf, PAGE_SIZE, "0\n");
2541         return snprintf(buf, PAGE_SIZE, "%llu\n",
2542                         (unsigned long long)(sbi->s_kbytes_written +
2543                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2544                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2545 }
2546
2547 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2548                                           struct ext4_sb_info *sbi,
2549                                           const char *buf, size_t count)
2550 {
2551         unsigned long t;
2552
2553         if (parse_strtoul(buf, 0x40000000, &t))
2554                 return -EINVAL;
2555
2556         if (t && !is_power_of_2(t))
2557                 return -EINVAL;
2558
2559         sbi->s_inode_readahead_blks = t;
2560         return count;
2561 }
2562
2563 static ssize_t sbi_ui_show(struct ext4_attr *a,
2564                            struct ext4_sb_info *sbi, char *buf)
2565 {
2566         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2567
2568         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2569 }
2570
2571 static ssize_t sbi_ui_store(struct ext4_attr *a,
2572                             struct ext4_sb_info *sbi,
2573                             const char *buf, size_t count)
2574 {
2575         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2576         unsigned long t;
2577
2578         if (parse_strtoul(buf, 0xffffffff, &t))
2579                 return -EINVAL;
2580         *ui = t;
2581         return count;
2582 }
2583
2584 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2585 static struct ext4_attr ext4_attr_##_name = {                   \
2586         .attr = {.name = __stringify(_name), .mode = _mode },   \
2587         .show   = _show,                                        \
2588         .store  = _store,                                       \
2589         .offset = offsetof(struct ext4_sb_info, _elname),       \
2590 }
2591 #define EXT4_ATTR(name, mode, show, store) \
2592 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2593
2594 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2595 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2596 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2597 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2598         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2599 #define ATTR_LIST(name) &ext4_attr_##name.attr
2600
2601 EXT4_RO_ATTR(delayed_allocation_blocks);
2602 EXT4_RO_ATTR(session_write_kbytes);
2603 EXT4_RO_ATTR(lifetime_write_kbytes);
2604 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2605                  inode_readahead_blks_store, s_inode_readahead_blks);
2606 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2607 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2608 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2609 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2610 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2611 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2612 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2613 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2614
2615 static struct attribute *ext4_attrs[] = {
2616         ATTR_LIST(delayed_allocation_blocks),
2617         ATTR_LIST(session_write_kbytes),
2618         ATTR_LIST(lifetime_write_kbytes),
2619         ATTR_LIST(inode_readahead_blks),
2620         ATTR_LIST(inode_goal),
2621         ATTR_LIST(mb_stats),
2622         ATTR_LIST(mb_max_to_scan),
2623         ATTR_LIST(mb_min_to_scan),
2624         ATTR_LIST(mb_order2_req),
2625         ATTR_LIST(mb_stream_req),
2626         ATTR_LIST(mb_group_prealloc),
2627         ATTR_LIST(max_writeback_mb_bump),
2628         NULL,
2629 };
2630
2631 /* Features this copy of ext4 supports */
2632 EXT4_INFO_ATTR(lazy_itable_init);
2633 EXT4_INFO_ATTR(batched_discard);
2634
2635 static struct attribute *ext4_feat_attrs[] = {
2636         ATTR_LIST(lazy_itable_init),
2637         ATTR_LIST(batched_discard),
2638         NULL,
2639 };
2640
2641 static ssize_t ext4_attr_show(struct kobject *kobj,
2642                               struct attribute *attr, char *buf)
2643 {
2644         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2645                                                 s_kobj);
2646         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2647
2648         return a->show ? a->show(a, sbi, buf) : 0;
2649 }
2650
2651 static ssize_t ext4_attr_store(struct kobject *kobj,
2652                                struct attribute *attr,
2653                                const char *buf, size_t len)
2654 {
2655         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2656                                                 s_kobj);
2657         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2658
2659         return a->store ? a->store(a, sbi, buf, len) : 0;
2660 }
2661
2662 static void ext4_sb_release(struct kobject *kobj)
2663 {
2664         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2665                                                 s_kobj);
2666         complete(&sbi->s_kobj_unregister);
2667 }
2668
2669 static const struct sysfs_ops ext4_attr_ops = {
2670         .show   = ext4_attr_show,
2671         .store  = ext4_attr_store,
2672 };
2673
2674 static struct kobj_type ext4_ktype = {
2675         .default_attrs  = ext4_attrs,
2676         .sysfs_ops      = &ext4_attr_ops,
2677         .release        = ext4_sb_release,
2678 };
2679
2680 static void ext4_feat_release(struct kobject *kobj)
2681 {
2682         complete(&ext4_feat->f_kobj_unregister);
2683 }
2684
2685 static struct kobj_type ext4_feat_ktype = {
2686         .default_attrs  = ext4_feat_attrs,
2687         .sysfs_ops      = &ext4_attr_ops,
2688         .release        = ext4_feat_release,
2689 };
2690
2691 /*
2692  * Check whether this filesystem can be mounted based on
2693  * the features present and the RDONLY/RDWR mount requested.
2694  * Returns 1 if this filesystem can be mounted as requested,
2695  * 0 if it cannot be.
2696  */
2697 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2698 {
2699         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2700                 ext4_msg(sb, KERN_ERR,
2701                         "Couldn't mount because of "
2702                         "unsupported optional features (%x)",
2703                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2704                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2705                 return 0;
2706         }
2707
2708         if (readonly)
2709                 return 1;
2710
2711         /* Check that feature set is OK for a read-write mount */
2712         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2713                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2714                          "unsupported optional features (%x)",
2715                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2716                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2717                 return 0;
2718         }
2719         /*
2720          * Large file size enabled file system can only be mounted
2721          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2722          */
2723         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2724                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2725                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2726                                  "cannot be mounted RDWR without "
2727                                  "CONFIG_LBDAF");
2728                         return 0;
2729                 }
2730         }
2731         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2732             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2733                 ext4_msg(sb, KERN_ERR,
2734                          "Can't support bigalloc feature without "
2735                          "extents feature\n");
2736                 return 0;
2737         }
2738         return 1;
2739 }
2740
2741 /*
2742  * This function is called once a day if we have errors logged
2743  * on the file system
2744  */
2745 static void print_daily_error_info(unsigned long arg)
2746 {
2747         struct super_block *sb = (struct super_block *) arg;
2748         struct ext4_sb_info *sbi;
2749         struct ext4_super_block *es;
2750
2751         sbi = EXT4_SB(sb);
2752         es = sbi->s_es;
2753
2754         if (es->s_error_count)
2755                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2756                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2757                          le32_to_cpu(es->s_error_count));
2758         if (es->s_first_error_time) {
2759                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2760                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2761                        (int) sizeof(es->s_first_error_func),
2762                        es->s_first_error_func,
2763                        le32_to_cpu(es->s_first_error_line));
2764                 if (es->s_first_error_ino)
2765                         printk(": inode %u",
2766                                le32_to_cpu(es->s_first_error_ino));
2767                 if (es->s_first_error_block)
2768                         printk(": block %llu", (unsigned long long)
2769                                le64_to_cpu(es->s_first_error_block));
2770                 printk("\n");
2771         }
2772         if (es->s_last_error_time) {
2773                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2774                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2775                        (int) sizeof(es->s_last_error_func),
2776                        es->s_last_error_func,
2777                        le32_to_cpu(es->s_last_error_line));
2778                 if (es->s_last_error_ino)
2779                         printk(": inode %u",
2780                                le32_to_cpu(es->s_last_error_ino));
2781                 if (es->s_last_error_block)
2782                         printk(": block %llu", (unsigned long long)
2783                                le64_to_cpu(es->s_last_error_block));
2784                 printk("\n");
2785         }
2786         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2787 }
2788
2789 /* Find next suitable group and run ext4_init_inode_table */
2790 static int ext4_run_li_request(struct ext4_li_request *elr)
2791 {
2792         struct ext4_group_desc *gdp = NULL;
2793         ext4_group_t group, ngroups;
2794         struct super_block *sb;
2795         unsigned long timeout = 0;
2796         int ret = 0;
2797
2798         sb = elr->lr_super;
2799         ngroups = EXT4_SB(sb)->s_groups_count;
2800
2801         for (group = elr->lr_next_group; group < ngroups; group++) {
2802                 gdp = ext4_get_group_desc(sb, group, NULL);
2803                 if (!gdp) {
2804                         ret = 1;
2805                         break;
2806                 }
2807
2808                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2809                         break;
2810         }
2811
2812         if (group == ngroups)
2813                 ret = 1;
2814
2815         if (!ret) {
2816                 timeout = jiffies;
2817                 ret = ext4_init_inode_table(sb, group,
2818                                             elr->lr_timeout ? 0 : 1);
2819                 if (elr->lr_timeout == 0) {
2820                         timeout = (jiffies - timeout) *
2821                                   elr->lr_sbi->s_li_wait_mult;
2822                         elr->lr_timeout = timeout;
2823                 }
2824                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2825                 elr->lr_next_group = group + 1;
2826         }
2827
2828         return ret;
2829 }
2830
2831 /*
2832  * Remove lr_request from the list_request and free the
2833  * request structure. Should be called with li_list_mtx held
2834  */
2835 static void ext4_remove_li_request(struct ext4_li_request *elr)
2836 {
2837         struct ext4_sb_info *sbi;
2838
2839         if (!elr)
2840                 return;
2841
2842         sbi = elr->lr_sbi;
2843
2844         list_del(&elr->lr_request);
2845         sbi->s_li_request = NULL;
2846         kfree(elr);
2847 }
2848
2849 static void ext4_unregister_li_request(struct super_block *sb)
2850 {
2851         mutex_lock(&ext4_li_mtx);
2852         if (!ext4_li_info) {
2853                 mutex_unlock(&ext4_li_mtx);
2854                 return;
2855         }
2856
2857         mutex_lock(&ext4_li_info->li_list_mtx);
2858         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2859         mutex_unlock(&ext4_li_info->li_list_mtx);
2860         mutex_unlock(&ext4_li_mtx);
2861 }
2862
2863 static struct task_struct *ext4_lazyinit_task;
2864
2865 /*
2866  * This is the function where ext4lazyinit thread lives. It walks
2867  * through the request list searching for next scheduled filesystem.
2868  * When such a fs is found, run the lazy initialization request
2869  * (ext4_rn_li_request) and keep track of the time spend in this
2870  * function. Based on that time we compute next schedule time of
2871  * the request. When walking through the list is complete, compute
2872  * next waking time and put itself into sleep.
2873  */
2874 static int ext4_lazyinit_thread(void *arg)
2875 {
2876         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2877         struct list_head *pos, *n;
2878         struct ext4_li_request *elr;
2879         unsigned long next_wakeup, cur;
2880
2881         BUG_ON(NULL == eli);
2882
2883 cont_thread:
2884         while (true) {
2885                 next_wakeup = MAX_JIFFY_OFFSET;
2886
2887                 mutex_lock(&eli->li_list_mtx);
2888                 if (list_empty(&eli->li_request_list)) {
2889                         mutex_unlock(&eli->li_list_mtx);
2890                         goto exit_thread;
2891                 }
2892
2893                 list_for_each_safe(pos, n, &eli->li_request_list) {
2894                         elr = list_entry(pos, struct ext4_li_request,
2895                                          lr_request);
2896
2897                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2898                                 if (ext4_run_li_request(elr) != 0) {
2899                                         /* error, remove the lazy_init job */
2900                                         ext4_remove_li_request(elr);
2901                                         continue;
2902                                 }
2903                         }
2904
2905                         if (time_before(elr->lr_next_sched, next_wakeup))
2906                                 next_wakeup = elr->lr_next_sched;
2907                 }
2908                 mutex_unlock(&eli->li_list_mtx);
2909
2910                 if (freezing(current))
2911                         refrigerator();
2912
2913                 cur = jiffies;
2914                 if ((time_after_eq(cur, next_wakeup)) ||
2915                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2916                         cond_resched();
2917                         continue;
2918                 }
2919
2920                 schedule_timeout_interruptible(next_wakeup - cur);
2921
2922                 if (kthread_should_stop()) {
2923                         ext4_clear_request_list();
2924                         goto exit_thread;
2925                 }
2926         }
2927
2928 exit_thread:
2929         /*
2930          * It looks like the request list is empty, but we need
2931          * to check it under the li_list_mtx lock, to prevent any
2932          * additions into it, and of course we should lock ext4_li_mtx
2933          * to atomically free the list and ext4_li_info, because at
2934          * this point another ext4 filesystem could be registering
2935          * new one.
2936          */
2937         mutex_lock(&ext4_li_mtx);
2938         mutex_lock(&eli->li_list_mtx);
2939         if (!list_empty(&eli->li_request_list)) {
2940                 mutex_unlock(&eli->li_list_mtx);
2941                 mutex_unlock(&ext4_li_mtx);
2942                 goto cont_thread;
2943         }
2944         mutex_unlock(&eli->li_list_mtx);
2945         kfree(ext4_li_info);
2946         ext4_li_info = NULL;
2947         mutex_unlock(&ext4_li_mtx);
2948
2949         return 0;
2950 }
2951
2952 static void ext4_clear_request_list(void)
2953 {
2954         struct list_head *pos, *n;
2955         struct ext4_li_request *elr;
2956
2957         mutex_lock(&ext4_li_info->li_list_mtx);
2958         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2959                 elr = list_entry(pos, struct ext4_li_request,
2960                                  lr_request);
2961                 ext4_remove_li_request(elr);
2962         }
2963         mutex_unlock(&ext4_li_info->li_list_mtx);
2964 }
2965
2966 static int ext4_run_lazyinit_thread(void)
2967 {
2968         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2969                                          ext4_li_info, "ext4lazyinit");
2970         if (IS_ERR(ext4_lazyinit_task)) {
2971                 int err = PTR_ERR(ext4_lazyinit_task);
2972                 ext4_clear_request_list();
2973                 kfree(ext4_li_info);
2974                 ext4_li_info = NULL;
2975                 printk(KERN_CRIT "EXT4: error %d creating inode table "
2976                                  "initialization thread\n",
2977                                  err);
2978                 return err;
2979         }
2980         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2981         return 0;
2982 }
2983
2984 /*
2985  * Check whether it make sense to run itable init. thread or not.
2986  * If there is at least one uninitialized inode table, return
2987  * corresponding group number, else the loop goes through all
2988  * groups and return total number of groups.
2989  */
2990 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2991 {
2992         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2993         struct ext4_group_desc *gdp = NULL;
2994
2995         for (group = 0; group < ngroups; group++) {
2996                 gdp = ext4_get_group_desc(sb, group, NULL);
2997                 if (!gdp)
2998                         continue;
2999
3000                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3001                         break;
3002         }
3003
3004         return group;
3005 }
3006
3007 static int ext4_li_info_new(void)
3008 {
3009         struct ext4_lazy_init *eli = NULL;
3010
3011         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3012         if (!eli)
3013                 return -ENOMEM;
3014
3015         INIT_LIST_HEAD(&eli->li_request_list);
3016         mutex_init(&eli->li_list_mtx);
3017
3018         eli->li_state |= EXT4_LAZYINIT_QUIT;
3019
3020         ext4_li_info = eli;
3021
3022         return 0;
3023 }
3024
3025 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3026                                             ext4_group_t start)
3027 {
3028         struct ext4_sb_info *sbi = EXT4_SB(sb);
3029         struct ext4_li_request *elr;
3030         unsigned long rnd;
3031
3032         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3033         if (!elr)
3034                 return NULL;
3035
3036         elr->lr_super = sb;
3037         elr->lr_sbi = sbi;
3038         elr->lr_next_group = start;
3039
3040         /*
3041          * Randomize first schedule time of the request to
3042          * spread the inode table initialization requests
3043          * better.
3044          */
3045         get_random_bytes(&rnd, sizeof(rnd));
3046         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3047                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3048
3049         return elr;
3050 }
3051
3052 static int ext4_register_li_request(struct super_block *sb,
3053                                     ext4_group_t first_not_zeroed)
3054 {
3055         struct ext4_sb_info *sbi = EXT4_SB(sb);
3056         struct ext4_li_request *elr;
3057         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3058         int ret = 0;
3059
3060         if (sbi->s_li_request != NULL) {
3061                 /*
3062                  * Reset timeout so it can be computed again, because
3063                  * s_li_wait_mult might have changed.
3064                  */
3065                 sbi->s_li_request->lr_timeout = 0;
3066                 return 0;
3067         }
3068
3069         if (first_not_zeroed == ngroups ||
3070             (sb->s_flags & MS_RDONLY) ||
3071             !test_opt(sb, INIT_INODE_TABLE))
3072                 return 0;
3073
3074         elr = ext4_li_request_new(sb, first_not_zeroed);
3075         if (!elr)
3076                 return -ENOMEM;
3077
3078         mutex_lock(&ext4_li_mtx);
3079
3080         if (NULL == ext4_li_info) {
3081                 ret = ext4_li_info_new();
3082                 if (ret)
3083                         goto out;
3084         }
3085
3086         mutex_lock(&ext4_li_info->li_list_mtx);
3087         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3088         mutex_unlock(&ext4_li_info->li_list_mtx);
3089
3090         sbi->s_li_request = elr;
3091         /*
3092          * set elr to NULL here since it has been inserted to
3093          * the request_list and the removal and free of it is
3094          * handled by ext4_clear_request_list from now on.
3095          */
3096         elr = NULL;
3097
3098         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3099                 ret = ext4_run_lazyinit_thread();
3100                 if (ret)
3101                         goto out;
3102         }
3103 out:
3104         mutex_unlock(&ext4_li_mtx);
3105         if (ret)
3106                 kfree(elr);
3107         return ret;
3108 }
3109
3110 /*
3111  * We do not need to lock anything since this is called on
3112  * module unload.
3113  */
3114 static void ext4_destroy_lazyinit_thread(void)
3115 {
3116         /*
3117          * If thread exited earlier
3118          * there's nothing to be done.
3119          */
3120         if (!ext4_li_info || !ext4_lazyinit_task)
3121                 return;
3122
3123         kthread_stop(ext4_lazyinit_task);
3124 }
3125
3126 /*
3127  * Note: calculating the overhead so we can be compatible with
3128  * historical BSD practice is quite difficult in the face of
3129  * clusters/bigalloc.  This is because multiple metadata blocks from
3130  * different block group can end up in the same allocation cluster.
3131  * Calculating the exact overhead in the face of clustered allocation
3132  * requires either O(all block bitmaps) in memory or O(number of block
3133  * groups**2) in time.  We will still calculate the superblock for
3134  * older file systems --- and if we come across with a bigalloc file
3135  * system with zero in s_overhead_clusters the estimate will be close to
3136  * correct especially for very large cluster sizes --- but for newer
3137  * file systems, it's better to calculate this figure once at mkfs
3138  * time, and store it in the superblock.  If the superblock value is
3139  * present (even for non-bigalloc file systems), we will use it.
3140  */
3141 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3142                           char *buf)
3143 {
3144         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3145         struct ext4_group_desc  *gdp;
3146         ext4_fsblk_t            first_block, last_block, b;
3147         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3148         int                     s, j, count = 0;
3149
3150         if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3151                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3152                         sbi->s_itb_per_group + 2);
3153
3154         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3155                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3156         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3157         for (i = 0; i < ngroups; i++) {
3158                 gdp = ext4_get_group_desc(sb, i, NULL);
3159                 b = ext4_block_bitmap(sb, gdp);
3160                 if (b >= first_block && b <= last_block) {
3161                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3162                         count++;
3163                 }
3164                 b = ext4_inode_bitmap(sb, gdp);
3165                 if (b >= first_block && b <= last_block) {
3166                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3167                         count++;
3168                 }
3169                 b = ext4_inode_table(sb, gdp);
3170                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3171                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3172                                 int c = EXT4_B2C(sbi, b - first_block);
3173                                 ext4_set_bit(c, buf);
3174                                 count++;
3175                         }
3176                 if (i != grp)
3177                         continue;
3178                 s = 0;
3179                 if (ext4_bg_has_super(sb, grp)) {
3180                         ext4_set_bit(s++, buf);
3181                         count++;
3182                 }
3183                 j = ext4_bg_num_gdb(sb, grp);
3184                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3185                         ext4_error(sb, "Invalid number of block group "
3186                                    "descriptor blocks: %d", j);
3187                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3188                 }
3189                 count += j;
3190                 for (; j > 0; j--)
3191                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3192         }
3193         if (!count)
3194                 return 0;
3195         return EXT4_CLUSTERS_PER_GROUP(sb) -
3196                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3197 }
3198
3199 /*
3200  * Compute the overhead and stash it in sbi->s_overhead
3201  */
3202 int ext4_calculate_overhead(struct super_block *sb)
3203 {
3204         struct ext4_sb_info *sbi = EXT4_SB(sb);
3205         struct ext4_super_block *es = sbi->s_es;
3206         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3207         ext4_fsblk_t overhead = 0;
3208         char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3209
3210         memset(buf, 0, PAGE_SIZE);
3211         if (!buf)
3212                 return -ENOMEM;
3213
3214         /*
3215          * Compute the overhead (FS structures).  This is constant
3216          * for a given filesystem unless the number of block groups
3217          * changes so we cache the previous value until it does.
3218          */
3219
3220         /*
3221          * All of the blocks before first_data_block are overhead
3222          */
3223         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3224
3225         /*
3226          * Add the overhead found in each block group
3227          */
3228         for (i = 0; i < ngroups; i++) {
3229                 int blks;
3230
3231                 blks = count_overhead(sb, i, buf);
3232                 overhead += blks;
3233                 if (blks)
3234                         memset(buf, 0, PAGE_SIZE);
3235                 cond_resched();
3236         }
3237         sbi->s_overhead = overhead;
3238         smp_wmb();
3239         free_page((unsigned long) buf);
3240         return 0;
3241 }
3242
3243 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3244 {
3245         char *orig_data = kstrdup(data, GFP_KERNEL);
3246         struct buffer_head *bh;
3247         struct ext4_super_block *es = NULL;
3248         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3249         ext4_fsblk_t block;
3250         ext4_fsblk_t sb_block = get_sb_block(&data);
3251         ext4_fsblk_t logical_sb_block;
3252         unsigned long offset = 0;
3253         unsigned long journal_devnum = 0;
3254         unsigned long def_mount_opts;
3255         struct inode *root;
3256         char *cp;
3257         const char *descr;
3258         int ret = -ENOMEM;
3259         int blocksize, clustersize;
3260         unsigned int db_count;
3261         unsigned int i;
3262         int needs_recovery, has_huge_files, has_bigalloc;
3263         __u64 blocks_count;
3264         int err;
3265         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3266         ext4_group_t first_not_zeroed;
3267
3268         if ((data && !orig_data) || !sbi)
3269                 goto out_free_base;
3270
3271         sbi->s_blockgroup_lock =
3272                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3273         if (!sbi->s_blockgroup_lock)
3274                 goto out_free_base;
3275
3276         sb->s_fs_info = sbi;
3277         sbi->s_mount_opt = 0;
3278         sbi->s_resuid = EXT4_DEF_RESUID;
3279         sbi->s_resgid = EXT4_DEF_RESGID;
3280         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3281         sbi->s_sb_block = sb_block;
3282         if (sb->s_bdev->bd_part)
3283                 sbi->s_sectors_written_start =
3284                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3285
3286         /* Cleanup superblock name */
3287         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3288                 *cp = '!';
3289
3290         ret = -EINVAL;
3291         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3292         if (!blocksize) {
3293                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3294                 goto out_fail;
3295         }
3296
3297         /*
3298          * The ext4 superblock will not be buffer aligned for other than 1kB
3299          * block sizes.  We need to calculate the offset from buffer start.
3300          */
3301         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3302                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3303                 offset = do_div(logical_sb_block, blocksize);
3304         } else {
3305                 logical_sb_block = sb_block;
3306         }
3307
3308         if (!(bh = sb_bread(sb, logical_sb_block))) {
3309                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3310                 goto out_fail;
3311         }
3312         /*
3313          * Note: s_es must be initialized as soon as possible because
3314          *       some ext4 macro-instructions depend on its value
3315          */
3316         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3317         sbi->s_es = es;
3318         sb->s_magic = le16_to_cpu(es->s_magic);
3319         if (sb->s_magic != EXT4_SUPER_MAGIC)
3320                 goto cantfind_ext4;
3321         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3322
3323         /* Set defaults before we parse the mount options */
3324         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3325         set_opt(sb, INIT_INODE_TABLE);
3326         if (def_mount_opts & EXT4_DEFM_DEBUG)
3327                 set_opt(sb, DEBUG);
3328         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3329                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3330                         "2.6.38");
3331                 set_opt(sb, GRPID);
3332         }
3333         if (def_mount_opts & EXT4_DEFM_UID16)
3334                 set_opt(sb, NO_UID32);
3335         /* xattr user namespace & acls are now defaulted on */
3336 #ifdef CONFIG_EXT4_FS_XATTR
3337         set_opt(sb, XATTR_USER);
3338 #endif
3339 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3340         set_opt(sb, POSIX_ACL);
3341 #endif
3342         set_opt(sb, MBLK_IO_SUBMIT);
3343         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3344                 set_opt(sb, JOURNAL_DATA);
3345         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3346                 set_opt(sb, ORDERED_DATA);
3347         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3348                 set_opt(sb, WRITEBACK_DATA);
3349
3350         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3351                 set_opt(sb, ERRORS_PANIC);
3352         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3353                 set_opt(sb, ERRORS_CONT);
3354         else
3355                 set_opt(sb, ERRORS_RO);
3356         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3357                 set_opt(sb, BLOCK_VALIDITY);
3358         if (def_mount_opts & EXT4_DEFM_DISCARD)
3359                 set_opt(sb, DISCARD);
3360
3361         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3362         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3363         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3364         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3365         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3366
3367         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3368                 set_opt(sb, BARRIER);
3369
3370         /*
3371          * enable delayed allocation by default
3372          * Use -o nodelalloc to turn it off
3373          */
3374         if (!IS_EXT3_SB(sb) &&
3375             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3376                 set_opt(sb, DELALLOC);
3377
3378         /*
3379          * set default s_li_wait_mult for lazyinit, for the case there is
3380          * no mount option specified.
3381          */
3382         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3383
3384         if (sbi->s_es->s_mount_opts[0]) {
3385                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3386                                               sizeof(sbi->s_es->s_mount_opts),
3387                                               GFP_KERNEL);
3388                 if (!s_mount_opts)
3389                         goto failed_mount;
3390                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3391                                    &journal_ioprio, NULL, 0)) {
3392                         ext4_msg(sb, KERN_WARNING,
3393                                  "failed to parse options in superblock: %s",
3394                                  s_mount_opts);
3395                 }
3396                 kfree(s_mount_opts);
3397         }
3398         if (!parse_options((char *) data, sb, &journal_devnum,
3399                            &journal_ioprio, NULL, 0))
3400                 goto failed_mount;
3401
3402         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3403                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3404                             "with data=journal disables delayed "
3405                             "allocation and O_DIRECT support!\n");
3406                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3407                         ext4_msg(sb, KERN_ERR, "can't mount with "
3408                                  "both data=journal and delalloc");
3409                         goto failed_mount;
3410                 }
3411                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3412                         ext4_msg(sb, KERN_ERR, "can't mount with "
3413                                  "both data=journal and dioread_nolock");
3414                         goto failed_mount;
3415                 }
3416                 if (test_opt(sb, DELALLOC))
3417                         clear_opt(sb, DELALLOC);
3418         }
3419
3420         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3421                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3422
3423         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3424             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3425              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3426              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3427                 ext4_msg(sb, KERN_WARNING,
3428                        "feature flags set on rev 0 fs, "
3429                        "running e2fsck is recommended");
3430
3431         if (IS_EXT2_SB(sb)) {
3432                 if (ext2_feature_set_ok(sb))
3433                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3434                                  "using the ext4 subsystem");
3435                 else {
3436                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3437                                  "to feature incompatibilities");
3438                         goto failed_mount;
3439                 }
3440         }
3441
3442         if (IS_EXT3_SB(sb)) {
3443                 if (ext3_feature_set_ok(sb))
3444                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3445                                  "using the ext4 subsystem");
3446                 else {
3447                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3448                                  "to feature incompatibilities");
3449                         goto failed_mount;
3450                 }
3451         }
3452
3453         /*
3454          * Check feature flags regardless of the revision level, since we
3455          * previously didn't change the revision level when setting the flags,
3456          * so there is a chance incompat flags are set on a rev 0 filesystem.
3457          */
3458         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3459                 goto failed_mount;
3460
3461         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3462         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3463             blocksize > EXT4_MAX_BLOCK_SIZE) {
3464                 ext4_msg(sb, KERN_ERR,
3465                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3466                          blocksize, le32_to_cpu(es->s_log_block_size));
3467                 goto failed_mount;
3468         }
3469         if (le32_to_cpu(es->s_log_block_size) >
3470             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3471                 ext4_msg(sb, KERN_ERR,
3472                          "Invalid log block size: %u",
3473                          le32_to_cpu(es->s_log_block_size));
3474                 goto failed_mount;
3475         }
3476
3477         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3478                 ext4_msg(sb, KERN_ERR,
3479                          "Number of reserved GDT blocks insanely large: %d",
3480                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3481                 goto failed_mount;
3482         }
3483
3484         if (sb->s_blocksize != blocksize) {
3485                 /* Validate the filesystem blocksize */
3486                 if (!sb_set_blocksize(sb, blocksize)) {
3487                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3488                                         blocksize);
3489                         goto failed_mount;
3490                 }
3491
3492                 brelse(bh);
3493                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3494                 offset = do_div(logical_sb_block, blocksize);
3495                 bh = sb_bread(sb, logical_sb_block);
3496                 if (!bh) {
3497                         ext4_msg(sb, KERN_ERR,
3498                                "Can't read superblock on 2nd try");
3499                         goto failed_mount;
3500                 }
3501                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3502                 sbi->s_es = es;
3503                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3504                         ext4_msg(sb, KERN_ERR,
3505                                "Magic mismatch, very weird!");
3506                         goto failed_mount;
3507                 }
3508         }
3509
3510         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3511                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3512         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3513                                                       has_huge_files);
3514         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3515
3516         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3517                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3518                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3519         } else {
3520                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3521                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3522                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3523                     (!is_power_of_2(sbi->s_inode_size)) ||
3524                     (sbi->s_inode_size > blocksize)) {
3525                         ext4_msg(sb, KERN_ERR,
3526                                "unsupported inode size: %d",
3527                                sbi->s_inode_size);
3528                         goto failed_mount;
3529                 }
3530                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3531                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3532         }
3533
3534         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3535         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3536                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3537                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3538                     !is_power_of_2(sbi->s_desc_size)) {
3539                         ext4_msg(sb, KERN_ERR,
3540                                "unsupported descriptor size %lu",
3541                                sbi->s_desc_size);
3542                         goto failed_mount;
3543                 }
3544         } else
3545                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3546
3547         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3548         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3549
3550         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3551         if (sbi->s_inodes_per_block == 0)
3552                 goto cantfind_ext4;
3553         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3554             sbi->s_inodes_per_group > blocksize * 8) {
3555                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3556                          sbi->s_blocks_per_group);
3557                 goto failed_mount;
3558         }
3559         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3560                                         sbi->s_inodes_per_block;
3561         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3562         sbi->s_sbh = bh;
3563         sbi->s_mount_state = le16_to_cpu(es->s_state);
3564         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3565         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3566
3567         for (i = 0; i < 4; i++)
3568                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3569         sbi->s_def_hash_version = es->s_def_hash_version;
3570         i = le32_to_cpu(es->s_flags);
3571         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3572                 sbi->s_hash_unsigned = 3;
3573         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3574 #ifdef __CHAR_UNSIGNED__
3575                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3576                 sbi->s_hash_unsigned = 3;
3577 #else
3578                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3579 #endif
3580                 sb->s_dirt = 1;
3581         }
3582
3583         /* Handle clustersize */
3584         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3585         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3586                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3587         if (has_bigalloc) {
3588                 if (clustersize < blocksize) {
3589                         ext4_msg(sb, KERN_ERR,
3590                                  "cluster size (%d) smaller than "
3591                                  "block size (%d)", clustersize, blocksize);
3592                         goto failed_mount;
3593                 }
3594                 if (le32_to_cpu(es->s_log_cluster_size) >
3595                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3596                         ext4_msg(sb, KERN_ERR,
3597                                  "Invalid log cluster size: %u",
3598                                  le32_to_cpu(es->s_log_cluster_size));
3599                         goto failed_mount;
3600                 }
3601                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3602                         le32_to_cpu(es->s_log_block_size);
3603                 sbi->s_clusters_per_group =
3604                         le32_to_cpu(es->s_clusters_per_group);
3605                 if (sbi->s_clusters_per_group > blocksize * 8) {
3606                         ext4_msg(sb, KERN_ERR,
3607                                  "#clusters per group too big: %lu",
3608                                  sbi->s_clusters_per_group);
3609                         goto failed_mount;
3610                 }
3611                 if (sbi->s_blocks_per_group !=
3612                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3613                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3614                                  "clusters per group (%lu) inconsistent",
3615                                  sbi->s_blocks_per_group,
3616                                  sbi->s_clusters_per_group);
3617                         goto failed_mount;
3618                 }
3619         } else {
3620                 if (clustersize != blocksize) {
3621                         ext4_warning(sb, "fragment/cluster size (%d) != "
3622                                      "block size (%d)", clustersize,
3623                                      blocksize);
3624                         clustersize = blocksize;
3625                 }
3626                 if (sbi->s_blocks_per_group > blocksize * 8) {
3627                         ext4_msg(sb, KERN_ERR,
3628                                  "#blocks per group too big: %lu",
3629                                  sbi->s_blocks_per_group);
3630                         goto failed_mount;
3631                 }
3632                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3633                 sbi->s_cluster_bits = 0;
3634         }
3635         sbi->s_cluster_ratio = clustersize / blocksize;
3636
3637         /*
3638          * Test whether we have more sectors than will fit in sector_t,
3639          * and whether the max offset is addressable by the page cache.
3640          */
3641         err = generic_check_addressable(sb->s_blocksize_bits,
3642                                         ext4_blocks_count(es));
3643         if (err) {
3644                 ext4_msg(sb, KERN_ERR, "filesystem"
3645                          " too large to mount safely on this system");
3646                 if (sizeof(sector_t) < 8)
3647                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3648                 ret = err;
3649                 goto failed_mount;
3650         }
3651
3652         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3653                 goto cantfind_ext4;
3654
3655         /* check blocks count against device size */
3656         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3657         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3658                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3659                        "exceeds size of device (%llu blocks)",
3660                        ext4_blocks_count(es), blocks_count);
3661                 goto failed_mount;
3662         }
3663
3664         /*
3665          * It makes no sense for the first data block to be beyond the end
3666          * of the filesystem.
3667          */
3668         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3669                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3670                          "block %u is beyond end of filesystem (%llu)",
3671                          le32_to_cpu(es->s_first_data_block),
3672                          ext4_blocks_count(es));
3673                 goto failed_mount;
3674         }
3675         blocks_count = (ext4_blocks_count(es) -
3676                         le32_to_cpu(es->s_first_data_block) +
3677                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3678         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3679         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3680                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3681                        "(block count %llu, first data block %u, "
3682                        "blocks per group %lu)", sbi->s_groups_count,
3683                        ext4_blocks_count(es),
3684                        le32_to_cpu(es->s_first_data_block),
3685                        EXT4_BLOCKS_PER_GROUP(sb));
3686                 goto failed_mount;
3687         }
3688         sbi->s_groups_count = blocks_count;
3689         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3690                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3691         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3692                    EXT4_DESC_PER_BLOCK(sb);
3693         sbi->s_group_desc = ext4_kvmalloc(db_count *
3694                                           sizeof(struct buffer_head *),
3695                                           GFP_KERNEL);
3696         if (sbi->s_group_desc == NULL) {
3697                 ext4_msg(sb, KERN_ERR, "not enough memory");
3698                 goto failed_mount;
3699         }
3700
3701         if (ext4_proc_root)
3702                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3703
3704         bgl_lock_init(sbi->s_blockgroup_lock);
3705
3706         for (i = 0; i < db_count; i++) {
3707                 block = descriptor_loc(sb, logical_sb_block, i);
3708                 sbi->s_group_desc[i] = sb_bread(sb, block);
3709                 if (!sbi->s_group_desc[i]) {
3710                         ext4_msg(sb, KERN_ERR,
3711                                "can't read group descriptor %d", i);
3712                         db_count = i;
3713                         goto failed_mount2;
3714                 }
3715         }
3716         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3717                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3718                 goto failed_mount2;
3719         }
3720         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3721                 if (!ext4_fill_flex_info(sb)) {
3722                         ext4_msg(sb, KERN_ERR,
3723                                "unable to initialize "
3724                                "flex_bg meta info!");
3725                         goto failed_mount2;
3726                 }
3727
3728         sbi->s_gdb_count = db_count;
3729         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3730         spin_lock_init(&sbi->s_next_gen_lock);
3731
3732         init_timer(&sbi->s_err_report);
3733         sbi->s_err_report.function = print_daily_error_info;
3734         sbi->s_err_report.data = (unsigned long) sb;
3735
3736         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3737                         ext4_count_free_clusters(sb));
3738         if (!err) {
3739                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3740                                 ext4_count_free_inodes(sb));
3741         }
3742         if (!err) {
3743                 err = percpu_counter_init(&sbi->s_dirs_counter,
3744                                 ext4_count_dirs(sb));
3745         }
3746         if (!err) {
3747                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3748         }
3749         if (err) {
3750                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3751                 goto failed_mount3;
3752         }
3753
3754         sbi->s_stripe = ext4_get_stripe_size(sbi);
3755         sbi->s_max_writeback_mb_bump = 128;
3756
3757         /*
3758          * set up enough so that it can read an inode
3759          */
3760         if (!test_opt(sb, NOLOAD) &&
3761             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3762                 sb->s_op = &ext4_sops;
3763         else
3764                 sb->s_op = &ext4_nojournal_sops;
3765         sb->s_export_op = &ext4_export_ops;
3766         sb->s_xattr = ext4_xattr_handlers;
3767 #ifdef CONFIG_QUOTA
3768         sb->s_qcop = &ext4_qctl_operations;
3769         sb->dq_op = &ext4_quota_operations;
3770 #endif
3771         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3772
3773         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3774         mutex_init(&sbi->s_orphan_lock);
3775         sbi->s_resize_flags = 0;
3776
3777         sb->s_root = NULL;
3778
3779         needs_recovery = (es->s_last_orphan != 0 ||
3780                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3781                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3782
3783         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3784             !(sb->s_flags & MS_RDONLY))
3785                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3786                         goto failed_mount3;
3787
3788         /*
3789          * The first inode we look at is the journal inode.  Don't try
3790          * root first: it may be modified in the journal!
3791          */
3792         if (!test_opt(sb, NOLOAD) &&
3793             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3794                 if (ext4_load_journal(sb, es, journal_devnum))
3795                         goto failed_mount3;
3796         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3797               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3798                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3799                        "suppressed and not mounted read-only");
3800                 goto failed_mount_wq;
3801         } else {
3802                 clear_opt(sb, DATA_FLAGS);
3803                 sbi->s_journal = NULL;
3804                 needs_recovery = 0;
3805                 goto no_journal;
3806         }
3807
3808         if (ext4_blocks_count(es) > 0xffffffffULL &&
3809             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3810                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3811                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3812                 goto failed_mount_wq;
3813         }
3814
3815         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3816                 jbd2_journal_set_features(sbi->s_journal,
3817                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3818                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3819         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3820                 jbd2_journal_set_features(sbi->s_journal,
3821                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3822                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3823                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3824         } else {
3825                 jbd2_journal_clear_features(sbi->s_journal,
3826                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3827                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3828         }
3829
3830         /* We have now updated the journal if required, so we can
3831          * validate the data journaling mode. */
3832         switch (test_opt(sb, DATA_FLAGS)) {
3833         case 0:
3834                 /* No mode set, assume a default based on the journal
3835                  * capabilities: ORDERED_DATA if the journal can
3836                  * cope, else JOURNAL_DATA
3837                  */
3838                 if (jbd2_journal_check_available_features
3839                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3840                         set_opt(sb, ORDERED_DATA);
3841                 else
3842                         set_opt(sb, JOURNAL_DATA);
3843                 break;
3844
3845         case EXT4_MOUNT_ORDERED_DATA:
3846         case EXT4_MOUNT_WRITEBACK_DATA:
3847                 if (!jbd2_journal_check_available_features
3848                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3849                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3850                                "requested data journaling mode");
3851                         goto failed_mount_wq;
3852                 }
3853         default:
3854                 break;
3855         }
3856         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3857
3858         /*
3859          * The journal may have updated the bg summary counts, so we
3860          * need to update the global counters.
3861          */
3862         percpu_counter_set(&sbi->s_freeclusters_counter,
3863                            ext4_count_free_clusters(sb));
3864         percpu_counter_set(&sbi->s_freeinodes_counter,
3865                            ext4_count_free_inodes(sb));
3866         percpu_counter_set(&sbi->s_dirs_counter,
3867                            ext4_count_dirs(sb));
3868         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3869
3870 no_journal:
3871         /*
3872          * Get the # of file system overhead blocks from the
3873          * superblock if present.
3874          */
3875         if (es->s_overhead_clusters)
3876                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3877         else {
3878                 ret = ext4_calculate_overhead(sb);
3879                 if (ret)
3880                         goto failed_mount_wq;
3881         }
3882
3883         /*
3884          * The maximum number of concurrent works can be high and
3885          * concurrency isn't really necessary.  Limit it to 1.
3886          */
3887         EXT4_SB(sb)->dio_unwritten_wq =
3888                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3889         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3890                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3891                 goto failed_mount_wq;
3892         }
3893
3894         /*
3895          * The jbd2_journal_load will have done any necessary log recovery,
3896          * so we can safely mount the rest of the filesystem now.
3897          */
3898
3899         root = ext4_iget(sb, EXT4_ROOT_INO);
3900         if (IS_ERR(root)) {
3901                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3902                 ret = PTR_ERR(root);
3903                 root = NULL;
3904                 goto failed_mount4;
3905         }
3906         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3907                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3908                 goto failed_mount4;
3909         }
3910         sb->s_root = d_alloc_root(root);
3911         if (!sb->s_root) {
3912                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3913                 ret = -ENOMEM;
3914                 goto failed_mount4;
3915         }
3916
3917         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3918                 sb->s_flags |= MS_RDONLY;
3919
3920         /* determine the minimum size of new large inodes, if present */
3921         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3922                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3923                                                      EXT4_GOOD_OLD_INODE_SIZE;
3924                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3925                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3926                         if (sbi->s_want_extra_isize <
3927                             le16_to_cpu(es->s_want_extra_isize))
3928                                 sbi->s_want_extra_isize =
3929                                         le16_to_cpu(es->s_want_extra_isize);
3930                         if (sbi->s_want_extra_isize <
3931                             le16_to_cpu(es->s_min_extra_isize))
3932                                 sbi->s_want_extra_isize =
3933                                         le16_to_cpu(es->s_min_extra_isize);
3934                 }
3935         }
3936         /* Check if enough inode space is available */
3937         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3938                                                         sbi->s_inode_size) {
3939                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3940                                                        EXT4_GOOD_OLD_INODE_SIZE;
3941                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3942                          "available");
3943         }
3944
3945         err = ext4_setup_system_zone(sb);
3946         if (err) {
3947                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3948                          "zone (%d)", err);
3949                 goto failed_mount4;
3950         }
3951
3952         ext4_ext_init(sb);
3953         err = ext4_mb_init(sb, needs_recovery);
3954         if (err) {
3955                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3956                          err);
3957                 goto failed_mount5;
3958         }
3959
3960         err = ext4_register_li_request(sb, first_not_zeroed);
3961         if (err)
3962                 goto failed_mount6;
3963
3964         sbi->s_kobj.kset = ext4_kset;
3965         init_completion(&sbi->s_kobj_unregister);
3966         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3967                                    "%s", sb->s_id);
3968         if (err)
3969                 goto failed_mount7;
3970
3971         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3972         ext4_orphan_cleanup(sb, es);
3973         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3974         if (needs_recovery) {
3975                 ext4_msg(sb, KERN_INFO, "recovery complete");
3976                 ext4_mark_recovery_complete(sb, es);
3977         }
3978         if (EXT4_SB(sb)->s_journal) {
3979                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3980                         descr = " journalled data mode";
3981                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3982                         descr = " ordered data mode";
3983                 else
3984                         descr = " writeback data mode";
3985         } else
3986                 descr = "out journal";
3987
3988         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3989                  "Opts: %.*s%s%s", descr,
3990                  (int) sizeof(sbi->s_es->s_mount_opts),
3991                  sbi->s_es->s_mount_opts,
3992                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3993
3994         if (es->s_error_count)
3995                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3996
3997         kfree(orig_data);
3998         return 0;
3999
4000 cantfind_ext4:
4001         if (!silent)
4002                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4003         goto failed_mount;
4004
4005 failed_mount7:
4006         ext4_unregister_li_request(sb);
4007 failed_mount6:
4008         ext4_ext_release(sb);
4009 failed_mount5:
4010         ext4_mb_release(sb);
4011         ext4_release_system_zone(sb);
4012 failed_mount4:
4013         iput(root);
4014         sb->s_root = NULL;
4015         ext4_msg(sb, KERN_ERR, "mount failed");
4016         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4017 failed_mount_wq:
4018         if (sbi->s_journal) {
4019                 jbd2_journal_destroy(sbi->s_journal);
4020                 sbi->s_journal = NULL;
4021         }
4022 failed_mount3:
4023         del_timer_sync(&sbi->s_err_report);
4024         if (sbi->s_flex_groups)
4025                 ext4_kvfree(sbi->s_flex_groups);
4026         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4027         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4028         percpu_counter_destroy(&sbi->s_dirs_counter);
4029         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4030         if (sbi->s_mmp_tsk)
4031                 kthread_stop(sbi->s_mmp_tsk);
4032 failed_mount2:
4033         for (i = 0; i < db_count; i++)
4034                 brelse(sbi->s_group_desc[i]);
4035         ext4_kvfree(sbi->s_group_desc);
4036 failed_mount:
4037         if (sbi->s_proc) {
4038                 remove_proc_entry(sb->s_id, ext4_proc_root);
4039         }
4040 #ifdef CONFIG_QUOTA
4041         for (i = 0; i < MAXQUOTAS; i++)
4042                 kfree(sbi->s_qf_names[i]);
4043 #endif
4044         ext4_blkdev_remove(sbi);
4045         brelse(bh);
4046 out_fail:
4047         sb->s_fs_info = NULL;
4048         kfree(sbi->s_blockgroup_lock);
4049 out_free_base:
4050         kfree(sbi);
4051         kfree(orig_data);
4052         return ret;
4053 }
4054
4055 /*
4056  * Setup any per-fs journal parameters now.  We'll do this both on
4057  * initial mount, once the journal has been initialised but before we've
4058  * done any recovery; and again on any subsequent remount.
4059  */
4060 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4061 {
4062         struct ext4_sb_info *sbi = EXT4_SB(sb);
4063
4064         journal->j_commit_interval = sbi->s_commit_interval;
4065         journal->j_min_batch_time = sbi->s_min_batch_time;
4066         journal->j_max_batch_time = sbi->s_max_batch_time;
4067
4068         write_lock(&journal->j_state_lock);
4069         if (test_opt(sb, BARRIER))
4070                 journal->j_flags |= JBD2_BARRIER;
4071         else
4072                 journal->j_flags &= ~JBD2_BARRIER;
4073         if (test_opt(sb, DATA_ERR_ABORT))
4074                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4075         else
4076                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4077         write_unlock(&journal->j_state_lock);
4078 }
4079
4080 static journal_t *ext4_get_journal(struct super_block *sb,
4081                                    unsigned int journal_inum)
4082 {
4083         struct inode *journal_inode;
4084         journal_t *journal;
4085
4086         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4087
4088         /* First, test for the existence of a valid inode on disk.  Bad
4089          * things happen if we iget() an unused inode, as the subsequent
4090          * iput() will try to delete it. */
4091
4092         journal_inode = ext4_iget(sb, journal_inum);
4093         if (IS_ERR(journal_inode)) {
4094                 ext4_msg(sb, KERN_ERR, "no journal found");
4095                 return NULL;
4096         }
4097         if (!journal_inode->i_nlink) {
4098                 make_bad_inode(journal_inode);
4099                 iput(journal_inode);
4100                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4101                 return NULL;
4102         }
4103
4104         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4105                   journal_inode, journal_inode->i_size);
4106         if (!S_ISREG(journal_inode->i_mode)) {
4107                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4108                 iput(journal_inode);
4109                 return NULL;
4110         }
4111
4112         journal = jbd2_journal_init_inode(journal_inode);
4113         if (!journal) {
4114                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4115                 iput(journal_inode);
4116                 return NULL;
4117         }
4118         journal->j_private = sb;
4119         ext4_init_journal_params(sb, journal);
4120         return journal;
4121 }
4122
4123 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4124                                        dev_t j_dev)
4125 {
4126         struct buffer_head *bh;
4127         journal_t *journal;
4128         ext4_fsblk_t start;
4129         ext4_fsblk_t len;
4130         int hblock, blocksize;
4131         ext4_fsblk_t sb_block;
4132         unsigned long offset;
4133         struct ext4_super_block *es;
4134         struct block_device *bdev;
4135
4136         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4137
4138         bdev = ext4_blkdev_get(j_dev, sb);
4139         if (bdev == NULL)
4140                 return NULL;
4141
4142         blocksize = sb->s_blocksize;
4143         hblock = bdev_logical_block_size(bdev);
4144         if (blocksize < hblock) {
4145                 ext4_msg(sb, KERN_ERR,
4146                         "blocksize too small for journal device");
4147                 goto out_bdev;
4148         }
4149
4150         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4151         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4152         set_blocksize(bdev, blocksize);
4153         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4154                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4155                        "external journal");
4156                 goto out_bdev;
4157         }
4158
4159         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
4160         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4161             !(le32_to_cpu(es->s_feature_incompat) &
4162               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4163                 ext4_msg(sb, KERN_ERR, "external journal has "
4164                                         "bad superblock");
4165                 brelse(bh);
4166                 goto out_bdev;
4167         }
4168
4169         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4170                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4171                 brelse(bh);
4172                 goto out_bdev;
4173         }
4174
4175         len = ext4_blocks_count(es);
4176         start = sb_block + 1;
4177         brelse(bh);     /* we're done with the superblock */
4178
4179         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4180                                         start, len, blocksize);
4181         if (!journal) {
4182                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4183                 goto out_bdev;
4184         }
4185         journal->j_private = sb;
4186         ll_rw_block(READ, 1, &journal->j_sb_buffer);
4187         wait_on_buffer(journal->j_sb_buffer);
4188         if (!buffer_uptodate(journal->j_sb_buffer)) {
4189                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4190                 goto out_journal;
4191         }
4192         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4193                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4194                                         "user (unsupported) - %d",
4195                         be32_to_cpu(journal->j_superblock->s_nr_users));
4196                 goto out_journal;
4197         }
4198         EXT4_SB(sb)->journal_bdev = bdev;
4199         ext4_init_journal_params(sb, journal);
4200         return journal;
4201
4202 out_journal:
4203         jbd2_journal_destroy(journal);
4204 out_bdev:
4205         ext4_blkdev_put(bdev);
4206         return NULL;
4207 }
4208
4209 static int ext4_load_journal(struct super_block *sb,
4210                              struct ext4_super_block *es,
4211                              unsigned long journal_devnum)
4212 {
4213         journal_t *journal;
4214         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4215         dev_t journal_dev;
4216         int err = 0;
4217         int really_read_only;
4218
4219         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4220
4221         if (journal_devnum &&
4222             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4223                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4224                         "numbers have changed");
4225                 journal_dev = new_decode_dev(journal_devnum);
4226         } else
4227                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4228
4229         really_read_only = bdev_read_only(sb->s_bdev);
4230
4231         /*
4232          * Are we loading a blank journal or performing recovery after a
4233          * crash?  For recovery, we need to check in advance whether we
4234          * can get read-write access to the device.
4235          */
4236         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4237                 if (sb->s_flags & MS_RDONLY) {
4238                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4239                                         "required on readonly filesystem");
4240                         if (really_read_only) {
4241                                 ext4_msg(sb, KERN_ERR, "write access "
4242                                         "unavailable, cannot proceed");
4243                                 return -EROFS;
4244                         }
4245                         ext4_msg(sb, KERN_INFO, "write access will "
4246                                "be enabled during recovery");
4247                 }
4248         }
4249
4250         if (journal_inum && journal_dev) {
4251                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4252                        "and inode journals!");
4253                 return -EINVAL;
4254         }
4255
4256         if (journal_inum) {
4257                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4258                         return -EINVAL;
4259         } else {
4260                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4261                         return -EINVAL;
4262         }
4263
4264         if (!(journal->j_flags & JBD2_BARRIER))
4265                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4266
4267         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
4268                 err = jbd2_journal_update_format(journal);
4269                 if (err)  {
4270                         ext4_msg(sb, KERN_ERR, "error updating journal");
4271                         jbd2_journal_destroy(journal);
4272                         return err;
4273                 }
4274         }
4275
4276         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4277                 err = jbd2_journal_wipe(journal, !really_read_only);
4278         if (!err) {
4279                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4280                 if (save)
4281                         memcpy(save, ((char *) es) +
4282                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4283                 err = jbd2_journal_load(journal);
4284                 if (save)
4285                         memcpy(((char *) es) + EXT4_S_ERR_START,
4286                                save, EXT4_S_ERR_LEN);
4287                 kfree(save);
4288         }
4289
4290         if (err) {
4291                 ext4_msg(sb, KERN_ERR, "error loading journal");
4292                 jbd2_journal_destroy(journal);
4293                 return err;
4294         }
4295
4296         EXT4_SB(sb)->s_journal = journal;
4297         ext4_clear_journal_err(sb, es);
4298
4299         if (!really_read_only && journal_devnum &&
4300             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4301                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4302
4303                 /* Make sure we flush the recovery flag to disk. */
4304                 ext4_commit_super(sb, 1);
4305         }
4306
4307         return 0;
4308 }
4309
4310 static int ext4_commit_super(struct super_block *sb, int sync)
4311 {
4312         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4313         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4314         int error = 0;
4315
4316         if (!sbh || block_device_ejected(sb))
4317                 return error;
4318         if (buffer_write_io_error(sbh)) {
4319                 /*
4320                  * Oh, dear.  A previous attempt to write the
4321                  * superblock failed.  This could happen because the
4322                  * USB device was yanked out.  Or it could happen to
4323                  * be a transient write error and maybe the block will
4324                  * be remapped.  Nothing we can do but to retry the
4325                  * write and hope for the best.
4326                  */
4327                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4328                        "superblock detected");
4329                 clear_buffer_write_io_error(sbh);
4330                 set_buffer_uptodate(sbh);
4331         }
4332         /*
4333          * If the file system is mounted read-only, don't update the
4334          * superblock write time.  This avoids updating the superblock
4335          * write time when we are mounting the root file system
4336          * read/only but we need to replay the journal; at that point,
4337          * for people who are east of GMT and who make their clock
4338          * tick in localtime for Windows bug-for-bug compatibility,
4339          * the clock is set in the future, and this will cause e2fsck
4340          * to complain and force a full file system check.
4341          */
4342         if (!(sb->s_flags & MS_RDONLY))
4343                 es->s_wtime = cpu_to_le32(get_seconds());
4344         if (sb->s_bdev->bd_part)
4345                 es->s_kbytes_written =
4346                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4347                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4348                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4349         else
4350                 es->s_kbytes_written =
4351                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4352         ext4_free_blocks_count_set(es,
4353                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4354                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4355         es->s_free_inodes_count =
4356                 cpu_to_le32(percpu_counter_sum_positive(
4357                                 &EXT4_SB(sb)->s_freeinodes_counter));
4358         sb->s_dirt = 0;
4359         BUFFER_TRACE(sbh, "marking dirty");
4360         mark_buffer_dirty(sbh);
4361         if (sync) {
4362                 error = sync_dirty_buffer(sbh);
4363                 if (error)
4364                         return error;
4365
4366                 error = buffer_write_io_error(sbh);
4367                 if (error) {
4368                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4369                                "superblock");
4370                         clear_buffer_write_io_error(sbh);
4371                         set_buffer_uptodate(sbh);
4372                 }
4373         }
4374         return error;
4375 }
4376
4377 /*
4378  * Have we just finished recovery?  If so, and if we are mounting (or
4379  * remounting) the filesystem readonly, then we will end up with a
4380  * consistent fs on disk.  Record that fact.
4381  */
4382 static void ext4_mark_recovery_complete(struct super_block *sb,
4383                                         struct ext4_super_block *es)
4384 {
4385         journal_t *journal = EXT4_SB(sb)->s_journal;
4386
4387         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4388                 BUG_ON(journal != NULL);
4389                 return;
4390         }
4391         jbd2_journal_lock_updates(journal);
4392         if (jbd2_journal_flush(journal) < 0)
4393                 goto out;
4394
4395         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4396             sb->s_flags & MS_RDONLY) {
4397                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4398                 ext4_commit_super(sb, 1);
4399         }
4400
4401 out:
4402         jbd2_journal_unlock_updates(journal);
4403 }
4404
4405 /*
4406  * If we are mounting (or read-write remounting) a filesystem whose journal
4407  * has recorded an error from a previous lifetime, move that error to the
4408  * main filesystem now.
4409  */
4410 static void ext4_clear_journal_err(struct super_block *sb,
4411                                    struct ext4_super_block *es)
4412 {
4413         journal_t *journal;
4414         int j_errno;
4415         const char *errstr;
4416
4417         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4418
4419         journal = EXT4_SB(sb)->s_journal;
4420
4421         /*
4422          * Now check for any error status which may have been recorded in the
4423          * journal by a prior ext4_error() or ext4_abort()
4424          */
4425
4426         j_errno = jbd2_journal_errno(journal);
4427         if (j_errno) {
4428                 char nbuf[16];
4429
4430                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4431                 ext4_warning(sb, "Filesystem error recorded "
4432                              "from previous mount: %s", errstr);
4433                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4434
4435                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4436                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4437                 ext4_commit_super(sb, 1);
4438
4439                 jbd2_journal_clear_err(journal);
4440         }
4441 }
4442
4443 /*
4444  * Force the running and committing transactions to commit,
4445  * and wait on the commit.
4446  */
4447 int ext4_force_commit(struct super_block *sb)
4448 {
4449         journal_t *journal;
4450         int ret = 0;
4451
4452         if (sb->s_flags & MS_RDONLY)
4453                 return 0;
4454
4455         journal = EXT4_SB(sb)->s_journal;
4456         if (journal) {
4457                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
4458                 ret = ext4_journal_force_commit(journal);
4459         }
4460
4461         return ret;
4462 }
4463
4464 static void ext4_write_super(struct super_block *sb)
4465 {
4466         lock_super(sb);
4467         ext4_commit_super(sb, 1);
4468         unlock_super(sb);
4469 }
4470
4471 static int ext4_sync_fs(struct super_block *sb, int wait)
4472 {
4473         int ret = 0;
4474         tid_t target;
4475         struct ext4_sb_info *sbi = EXT4_SB(sb);
4476
4477         trace_ext4_sync_fs(sb, wait);
4478         flush_workqueue(sbi->dio_unwritten_wq);
4479         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4480                 if (wait)
4481                         jbd2_log_wait_commit(sbi->s_journal, target);
4482         }
4483         return ret;
4484 }
4485
4486 /*
4487  * LVM calls this function before a (read-only) snapshot is created.  This
4488  * gives us a chance to flush the journal completely and mark the fs clean.
4489  *
4490  * Note that only this function cannot bring a filesystem to be in a clean
4491  * state independently, because ext4 prevents a new handle from being started
4492  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4493  * the upper layer.
4494  */
4495 static int ext4_freeze(struct super_block *sb)
4496 {
4497         int error = 0;
4498         journal_t *journal;
4499
4500         if (sb->s_flags & MS_RDONLY)
4501                 return 0;
4502
4503         journal = EXT4_SB(sb)->s_journal;
4504
4505         /* Now we set up the journal barrier. */
4506         jbd2_journal_lock_updates(journal);
4507
4508         /*
4509          * Don't clear the needs_recovery flag if we failed to flush
4510          * the journal.
4511          */
4512         error = jbd2_journal_flush(journal);
4513         if (error < 0)
4514                 goto out;
4515
4516         /* Journal blocked and flushed, clear needs_recovery flag. */
4517         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4518         error = ext4_commit_super(sb, 1);
4519 out:
4520         /* we rely on s_frozen to stop further updates */
4521         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4522         return error;
4523 }
4524
4525 /*
4526  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4527  * flag here, even though the filesystem is not technically dirty yet.
4528  */
4529 static int ext4_unfreeze(struct super_block *sb)
4530 {
4531         if (sb->s_flags & MS_RDONLY)
4532                 return 0;
4533
4534         lock_super(sb);
4535         /* Reset the needs_recovery flag before the fs is unlocked. */
4536         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4537         ext4_commit_super(sb, 1);
4538         unlock_super(sb);
4539         return 0;
4540 }
4541
4542 /*
4543  * Structure to save mount options for ext4_remount's benefit
4544  */
4545 struct ext4_mount_options {
4546         unsigned long s_mount_opt;
4547         unsigned long s_mount_opt2;
4548         uid_t s_resuid;
4549         gid_t s_resgid;
4550         unsigned long s_commit_interval;
4551         u32 s_min_batch_time, s_max_batch_time;
4552 #ifdef CONFIG_QUOTA
4553         int s_jquota_fmt;
4554         char *s_qf_names[MAXQUOTAS];
4555 #endif
4556 };
4557
4558 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4559 {
4560         struct ext4_super_block *es;
4561         struct ext4_sb_info *sbi = EXT4_SB(sb);
4562         ext4_fsblk_t n_blocks_count = 0;
4563         unsigned long old_sb_flags;
4564         struct ext4_mount_options old_opts;
4565         int enable_quota = 0;
4566         ext4_group_t g;
4567         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4568         int err = 0;
4569 #ifdef CONFIG_QUOTA
4570         int i;
4571 #endif
4572         char *orig_data = kstrdup(data, GFP_KERNEL);
4573
4574         /* Store the original options */
4575         lock_super(sb);
4576         old_sb_flags = sb->s_flags;
4577         old_opts.s_mount_opt = sbi->s_mount_opt;
4578         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4579         old_opts.s_resuid = sbi->s_resuid;
4580         old_opts.s_resgid = sbi->s_resgid;
4581         old_opts.s_commit_interval = sbi->s_commit_interval;
4582         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4583         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4584 #ifdef CONFIG_QUOTA
4585         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4586         for (i = 0; i < MAXQUOTAS; i++)
4587                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4588 #endif
4589         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4590                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4591
4592         /*
4593          * Allow the "check" option to be passed as a remount option.
4594          */
4595         if (!parse_options(data, sb, NULL, &journal_ioprio,
4596                            &n_blocks_count, 1)) {
4597                 err = -EINVAL;
4598                 goto restore_opts;
4599         }
4600
4601         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4602                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4603                         ext4_msg(sb, KERN_ERR, "can't mount with "
4604                                  "both data=journal and delalloc");
4605                         err = -EINVAL;
4606                         goto restore_opts;
4607                 }
4608                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4609                         ext4_msg(sb, KERN_ERR, "can't mount with "
4610                                  "both data=journal and dioread_nolock");
4611                         err = -EINVAL;
4612                         goto restore_opts;
4613                 }
4614         }
4615
4616         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4617                 ext4_abort(sb, "Abort forced by user");
4618
4619         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4620                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4621
4622         es = sbi->s_es;
4623
4624         if (sbi->s_journal) {
4625                 ext4_init_journal_params(sb, sbi->s_journal);
4626                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4627         }
4628
4629         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4630                 n_blocks_count > ext4_blocks_count(es)) {
4631                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4632                         err = -EROFS;
4633                         goto restore_opts;
4634                 }
4635
4636                 if (*flags & MS_RDONLY) {
4637                         err = dquot_suspend(sb, -1);
4638                         if (err < 0)
4639                                 goto restore_opts;
4640
4641                         /*
4642                          * First of all, the unconditional stuff we have to do
4643                          * to disable replay of the journal when we next remount
4644                          */
4645                         sb->s_flags |= MS_RDONLY;
4646
4647                         /*
4648                          * OK, test if we are remounting a valid rw partition
4649                          * readonly, and if so set the rdonly flag and then
4650                          * mark the partition as valid again.
4651                          */
4652                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4653                             (sbi->s_mount_state & EXT4_VALID_FS))
4654                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4655
4656                         if (sbi->s_journal)
4657                                 ext4_mark_recovery_complete(sb, es);
4658                 } else {
4659                         /* Make sure we can mount this feature set readwrite */
4660                         if (!ext4_feature_set_ok(sb, 0)) {
4661                                 err = -EROFS;
4662                                 goto restore_opts;
4663                         }
4664                         /*
4665                          * Make sure the group descriptor checksums
4666                          * are sane.  If they aren't, refuse to remount r/w.
4667                          */
4668                         for (g = 0; g < sbi->s_groups_count; g++) {
4669                                 struct ext4_group_desc *gdp =
4670                                         ext4_get_group_desc(sb, g, NULL);
4671
4672                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4673                                         ext4_msg(sb, KERN_ERR,
4674                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4675                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4676                                                le16_to_cpu(gdp->bg_checksum));
4677                                         err = -EINVAL;
4678                                         goto restore_opts;
4679                                 }
4680                         }
4681
4682                         /*
4683                          * If we have an unprocessed orphan list hanging
4684                          * around from a previously readonly bdev mount,
4685                          * require a full umount/remount for now.
4686                          */
4687                         if (es->s_last_orphan) {
4688                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4689                                        "remount RDWR because of unprocessed "
4690                                        "orphan inode list.  Please "
4691                                        "umount/remount instead");
4692                                 err = -EINVAL;
4693                                 goto restore_opts;
4694                         }
4695
4696                         /*
4697                          * Mounting a RDONLY partition read-write, so reread
4698                          * and store the current valid flag.  (It may have
4699                          * been changed by e2fsck since we originally mounted
4700                          * the partition.)
4701                          */
4702                         if (sbi->s_journal)
4703                                 ext4_clear_journal_err(sb, es);
4704                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4705                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4706                                 goto restore_opts;
4707                         if (!ext4_setup_super(sb, es, 0))
4708                                 sb->s_flags &= ~MS_RDONLY;
4709                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4710                                                      EXT4_FEATURE_INCOMPAT_MMP))
4711                                 if (ext4_multi_mount_protect(sb,
4712                                                 le64_to_cpu(es->s_mmp_block))) {
4713                                         err = -EROFS;
4714                                         goto restore_opts;
4715                                 }
4716                         enable_quota = 1;
4717                 }
4718         }
4719
4720         /*
4721          * Reinitialize lazy itable initialization thread based on
4722          * current settings
4723          */
4724         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4725                 ext4_unregister_li_request(sb);
4726         else {
4727                 ext4_group_t first_not_zeroed;
4728                 first_not_zeroed = ext4_has_uninit_itable(sb);
4729                 ext4_register_li_request(sb, first_not_zeroed);
4730         }
4731
4732         ext4_setup_system_zone(sb);
4733         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4734                 ext4_commit_super(sb, 1);
4735
4736 #ifdef CONFIG_QUOTA
4737         /* Release old quota file names */
4738         for (i = 0; i < MAXQUOTAS; i++)
4739                 if (old_opts.s_qf_names[i] &&
4740                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4741                         kfree(old_opts.s_qf_names[i]);
4742 #endif
4743         unlock_super(sb);
4744         if (enable_quota)
4745                 dquot_resume(sb, -1);
4746
4747         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4748         kfree(orig_data);
4749         return 0;
4750
4751 restore_opts:
4752         sb->s_flags = old_sb_flags;
4753         sbi->s_mount_opt = old_opts.s_mount_opt;
4754         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4755         sbi->s_resuid = old_opts.s_resuid;
4756         sbi->s_resgid = old_opts.s_resgid;
4757         sbi->s_commit_interval = old_opts.s_commit_interval;
4758         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4759         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4760 #ifdef CONFIG_QUOTA
4761         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4762         for (i = 0; i < MAXQUOTAS; i++) {
4763                 if (sbi->s_qf_names[i] &&
4764                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4765                         kfree(sbi->s_qf_names[i]);
4766                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4767         }
4768 #endif
4769         unlock_super(sb);
4770         kfree(orig_data);
4771         return err;
4772 }
4773
4774 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4775 {
4776         struct super_block *sb = dentry->d_sb;
4777         struct ext4_sb_info *sbi = EXT4_SB(sb);
4778         struct ext4_super_block *es = sbi->s_es;
4779         ext4_fsblk_t overhead = 0;
4780         u64 fsid;
4781         s64 bfree;
4782
4783         if (!test_opt(sb, MINIX_DF))
4784                 overhead = sbi->s_overhead;
4785
4786         buf->f_type = EXT4_SUPER_MAGIC;
4787         buf->f_bsize = sb->s_blocksize;
4788         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4789         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4790                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4791         /* prevent underflow in case that few free space is available */
4792         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4793         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4794         if (buf->f_bfree < ext4_r_blocks_count(es))
4795                 buf->f_bavail = 0;
4796         buf->f_files = le32_to_cpu(es->s_inodes_count);
4797         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4798         buf->f_namelen = EXT4_NAME_LEN;
4799         fsid = le64_to_cpup((void *)es->s_uuid) ^
4800                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4801         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4802         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4803
4804         return 0;
4805 }
4806
4807 /* Helper function for writing quotas on sync - we need to start transaction
4808  * before quota file is locked for write. Otherwise the are possible deadlocks:
4809  * Process 1                         Process 2
4810  * ext4_create()                     quota_sync()
4811  *   jbd2_journal_start()                  write_dquot()
4812  *   dquot_initialize()                         down(dqio_mutex)
4813  *     down(dqio_mutex)                    jbd2_journal_start()
4814  *
4815  */
4816
4817 #ifdef CONFIG_QUOTA
4818
4819 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4820 {
4821         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4822 }
4823
4824 static int ext4_write_dquot(struct dquot *dquot)
4825 {
4826         int ret, err;
4827         handle_t *handle;
4828         struct inode *inode;
4829
4830         inode = dquot_to_inode(dquot);
4831         handle = ext4_journal_start(inode,
4832                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4833         if (IS_ERR(handle))
4834                 return PTR_ERR(handle);
4835         ret = dquot_commit(dquot);
4836         err = ext4_journal_stop(handle);
4837         if (!ret)
4838                 ret = err;
4839         return ret;
4840 }
4841
4842 static int ext4_acquire_dquot(struct dquot *dquot)
4843 {
4844         int ret, err;
4845         handle_t *handle;
4846
4847         handle = ext4_journal_start(dquot_to_inode(dquot),
4848                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4849         if (IS_ERR(handle))
4850                 return PTR_ERR(handle);
4851         ret = dquot_acquire(dquot);
4852         err = ext4_journal_stop(handle);
4853         if (!ret)
4854                 ret = err;
4855         return ret;
4856 }
4857
4858 static int ext4_release_dquot(struct dquot *dquot)
4859 {
4860         int ret, err;
4861         handle_t *handle;
4862
4863         handle = ext4_journal_start(dquot_to_inode(dquot),
4864                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4865         if (IS_ERR(handle)) {
4866                 /* Release dquot anyway to avoid endless cycle in dqput() */
4867                 dquot_release(dquot);
4868                 return PTR_ERR(handle);
4869         }
4870         ret = dquot_release(dquot);
4871         err = ext4_journal_stop(handle);
4872         if (!ret)
4873                 ret = err;
4874         return ret;
4875 }
4876
4877 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4878 {
4879         /* Are we journaling quotas? */
4880         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4881             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4882                 dquot_mark_dquot_dirty(dquot);
4883                 return ext4_write_dquot(dquot);
4884         } else {
4885                 return dquot_mark_dquot_dirty(dquot);
4886         }
4887 }
4888
4889 static int ext4_write_info(struct super_block *sb, int type)
4890 {
4891         int ret, err;
4892         handle_t *handle;
4893
4894         /* Data block + inode block */
4895         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4896         if (IS_ERR(handle))
4897                 return PTR_ERR(handle);
4898         ret = dquot_commit_info(sb, type);
4899         err = ext4_journal_stop(handle);
4900         if (!ret)
4901                 ret = err;
4902         return ret;
4903 }
4904
4905 /*
4906  * Turn on quotas during mount time - we need to find
4907  * the quota file and such...
4908  */
4909 static int ext4_quota_on_mount(struct super_block *sb, int type)
4910 {
4911         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4912                                         EXT4_SB(sb)->s_jquota_fmt, type);
4913 }
4914
4915 /*
4916  * Standard function to be called on quota_on
4917  */
4918 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4919                          struct path *path)
4920 {
4921         int err;
4922
4923         if (!test_opt(sb, QUOTA))
4924                 return -EINVAL;
4925
4926         /* Quotafile not on the same filesystem? */
4927         if (path->mnt->mnt_sb != sb)
4928                 return -EXDEV;
4929         /* Journaling quota? */
4930         if (EXT4_SB(sb)->s_qf_names[type]) {
4931                 /* Quotafile not in fs root? */
4932                 if (path->dentry->d_parent != sb->s_root)
4933                         ext4_msg(sb, KERN_WARNING,
4934                                 "Quota file not on filesystem root. "
4935                                 "Journaled quota will not work");
4936         }
4937
4938         /*
4939          * When we journal data on quota file, we have to flush journal to see
4940          * all updates to the file when we bypass pagecache...
4941          */
4942         if (EXT4_SB(sb)->s_journal &&
4943             ext4_should_journal_data(path->dentry->d_inode)) {
4944                 /*
4945                  * We don't need to lock updates but journal_flush() could
4946                  * otherwise be livelocked...
4947                  */
4948                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4949                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4950                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4951                 if (err)
4952                         return err;
4953         }
4954
4955         return dquot_quota_on(sb, type, format_id, path);
4956 }
4957
4958 static int ext4_quota_off(struct super_block *sb, int type)
4959 {
4960         struct inode *inode = sb_dqopt(sb)->files[type];
4961         handle_t *handle;
4962
4963         /* Force all delayed allocation blocks to be allocated.
4964          * Caller already holds s_umount sem */
4965         if (test_opt(sb, DELALLOC))
4966                 sync_filesystem(sb);
4967
4968         if (!inode)
4969                 goto out;
4970
4971         /* Update modification times of quota files when userspace can
4972          * start looking at them */
4973         handle = ext4_journal_start(inode, 1);
4974         if (IS_ERR(handle))
4975                 goto out;
4976         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4977         ext4_mark_inode_dirty(handle, inode);
4978         ext4_journal_stop(handle);
4979
4980 out:
4981         return dquot_quota_off(sb, type);
4982 }
4983
4984 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4985  * acquiring the locks... As quota files are never truncated and quota code
4986  * itself serializes the operations (and no one else should touch the files)
4987  * we don't have to be afraid of races */
4988 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4989                                size_t len, loff_t off)
4990 {
4991         struct inode *inode = sb_dqopt(sb)->files[type];
4992         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4993         int err = 0;
4994         int offset = off & (sb->s_blocksize - 1);
4995         int tocopy;
4996         size_t toread;
4997         struct buffer_head *bh;
4998         loff_t i_size = i_size_read(inode);
4999
5000         if (off > i_size)
5001                 return 0;
5002         if (off+len > i_size)
5003                 len = i_size-off;
5004         toread = len;
5005         while (toread > 0) {
5006                 tocopy = sb->s_blocksize - offset < toread ?
5007                                 sb->s_blocksize - offset : toread;
5008                 bh = ext4_bread(NULL, inode, blk, 0, &err);
5009                 if (err)
5010                         return err;
5011                 if (!bh)        /* A hole? */
5012                         memset(data, 0, tocopy);
5013                 else
5014                         memcpy(data, bh->b_data+offset, tocopy);
5015                 brelse(bh);
5016                 offset = 0;
5017                 toread -= tocopy;
5018                 data += tocopy;
5019                 blk++;
5020         }
5021         return len;
5022 }
5023
5024 /* Write to quotafile (we know the transaction is already started and has
5025  * enough credits) */
5026 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5027                                 const char *data, size_t len, loff_t off)
5028 {
5029         struct inode *inode = sb_dqopt(sb)->files[type];
5030         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5031         int err = 0;
5032         int offset = off & (sb->s_blocksize - 1);
5033         struct buffer_head *bh;
5034         handle_t *handle = journal_current_handle();
5035
5036         if (EXT4_SB(sb)->s_journal && !handle) {
5037                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5038                         " cancelled because transaction is not started",
5039                         (unsigned long long)off, (unsigned long long)len);
5040                 return -EIO;
5041         }
5042         /*
5043          * Since we account only one data block in transaction credits,
5044          * then it is impossible to cross a block boundary.
5045          */
5046         if (sb->s_blocksize - offset < len) {
5047                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5048                         " cancelled because not block aligned",
5049                         (unsigned long long)off, (unsigned long long)len);
5050                 return -EIO;
5051         }
5052
5053         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
5054         bh = ext4_bread(handle, inode, blk, 1, &err);
5055         if (!bh)
5056                 goto out;
5057         err = ext4_journal_get_write_access(handle, bh);
5058         if (err) {
5059                 brelse(bh);
5060                 goto out;
5061         }
5062         lock_buffer(bh);
5063         memcpy(bh->b_data+offset, data, len);
5064         flush_dcache_page(bh->b_page);
5065         unlock_buffer(bh);
5066         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5067         brelse(bh);
5068 out:
5069         if (err) {
5070                 mutex_unlock(&inode->i_mutex);
5071                 return err;
5072         }
5073         if (inode->i_size < off + len) {
5074                 i_size_write(inode, off + len);
5075                 EXT4_I(inode)->i_disksize = inode->i_size;
5076                 ext4_mark_inode_dirty(handle, inode);
5077         }
5078         mutex_unlock(&inode->i_mutex);
5079         return len;
5080 }
5081
5082 #endif
5083
5084 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5085                        const char *dev_name, void *data)
5086 {
5087         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5088 }
5089
5090 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5091 static inline void register_as_ext2(void)
5092 {
5093         int err = register_filesystem(&ext2_fs_type);
5094         if (err)
5095                 printk(KERN_WARNING
5096                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5097 }
5098
5099 static inline void unregister_as_ext2(void)
5100 {
5101         unregister_filesystem(&ext2_fs_type);
5102 }
5103
5104 static inline int ext2_feature_set_ok(struct super_block *sb)
5105 {
5106         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5107                 return 0;
5108         if (sb->s_flags & MS_RDONLY)
5109                 return 1;
5110         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5111                 return 0;
5112         return 1;
5113 }
5114 MODULE_ALIAS("ext2");
5115 #else
5116 static inline void register_as_ext2(void) { }
5117 static inline void unregister_as_ext2(void) { }
5118 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5119 #endif
5120
5121 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5122 static inline void register_as_ext3(void)
5123 {
5124         int err = register_filesystem(&ext3_fs_type);
5125         if (err)
5126                 printk(KERN_WARNING
5127                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5128 }
5129
5130 static inline void unregister_as_ext3(void)
5131 {
5132         unregister_filesystem(&ext3_fs_type);
5133 }
5134
5135 static inline int ext3_feature_set_ok(struct super_block *sb)
5136 {
5137         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5138                 return 0;
5139         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5140                 return 0;
5141         if (sb->s_flags & MS_RDONLY)
5142                 return 1;
5143         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5144                 return 0;
5145         return 1;
5146 }
5147 MODULE_ALIAS("ext3");
5148 #else
5149 static inline void register_as_ext3(void) { }
5150 static inline void unregister_as_ext3(void) { }
5151 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5152 #endif
5153
5154 static struct file_system_type ext4_fs_type = {
5155         .owner          = THIS_MODULE,
5156         .name           = "ext4",
5157         .mount          = ext4_mount,
5158         .kill_sb        = kill_block_super,
5159         .fs_flags       = FS_REQUIRES_DEV,
5160 };
5161
5162 static int __init ext4_init_feat_adverts(void)
5163 {
5164         struct ext4_features *ef;
5165         int ret = -ENOMEM;
5166
5167         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5168         if (!ef)
5169                 goto out;
5170
5171         ef->f_kobj.kset = ext4_kset;
5172         init_completion(&ef->f_kobj_unregister);
5173         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5174                                    "features");
5175         if (ret) {
5176                 kfree(ef);
5177                 goto out;
5178         }
5179
5180         ext4_feat = ef;
5181         ret = 0;
5182 out:
5183         return ret;
5184 }
5185
5186 static void ext4_exit_feat_adverts(void)
5187 {
5188         kobject_put(&ext4_feat->f_kobj);
5189         wait_for_completion(&ext4_feat->f_kobj_unregister);
5190         kfree(ext4_feat);
5191 }
5192
5193 /* Shared across all ext4 file systems */
5194 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5195 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5196
5197 static int __init ext4_init_fs(void)
5198 {
5199         int i, err;
5200
5201         ext4_check_flag_values();
5202
5203         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5204                 mutex_init(&ext4__aio_mutex[i]);
5205                 init_waitqueue_head(&ext4__ioend_wq[i]);
5206         }
5207
5208         err = ext4_init_pageio();
5209         if (err)
5210                 return err;
5211         err = ext4_init_system_zone();
5212         if (err)
5213                 goto out6;
5214         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5215         if (!ext4_kset)
5216                 goto out5;
5217         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5218
5219         err = ext4_init_feat_adverts();
5220         if (err)
5221                 goto out4;
5222
5223         err = ext4_init_mballoc();
5224         if (err)
5225                 goto out3;
5226
5227         err = ext4_init_xattr();
5228         if (err)
5229                 goto out2;
5230         err = init_inodecache();
5231         if (err)
5232                 goto out1;
5233         register_as_ext3();
5234         register_as_ext2();
5235         err = register_filesystem(&ext4_fs_type);
5236         if (err)
5237                 goto out;
5238
5239         ext4_li_info = NULL;
5240         mutex_init(&ext4_li_mtx);
5241         return 0;
5242 out:
5243         unregister_as_ext2();
5244         unregister_as_ext3();
5245         destroy_inodecache();
5246 out1:
5247         ext4_exit_xattr();
5248 out2:
5249         ext4_exit_mballoc();
5250 out3:
5251         ext4_exit_feat_adverts();
5252 out4:
5253         if (ext4_proc_root)
5254                 remove_proc_entry("fs/ext4", NULL);
5255         kset_unregister(ext4_kset);
5256 out5:
5257         ext4_exit_system_zone();
5258 out6:
5259         ext4_exit_pageio();
5260         return err;
5261 }
5262
5263 static void __exit ext4_exit_fs(void)
5264 {
5265         ext4_destroy_lazyinit_thread();
5266         unregister_as_ext2();
5267         unregister_as_ext3();
5268         unregister_filesystem(&ext4_fs_type);
5269         destroy_inodecache();
5270         ext4_exit_xattr();
5271         ext4_exit_mballoc();
5272         ext4_exit_feat_adverts();
5273         remove_proc_entry("fs/ext4", NULL);
5274         kset_unregister(ext4_kset);
5275         ext4_exit_system_zone();
5276         ext4_exit_pageio();
5277 }
5278
5279 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5280 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5281 MODULE_LICENSE("GPL");
5282 module_init(ext4_init_fs)
5283 module_exit(ext4_exit_fs)