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                 panic("EXT4-fs (device %s): panic forced after error\n",
 468                         sb->s_id);
 469 }
 470
 471 void __ext4_error(struct super_block *sb, const char *function,
 472                   unsigned int line, const char *fmt, ...)
 473 {
 474         struct va_format vaf;
 475         va_list args;
 476
 477         va_start(args, fmt);
 478         vaf.fmt = fmt;
 479         vaf.va = &args;
 480         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 481                sb->s_id, function, line, current->comm, &vaf);
 482         va_end(args);
 483
 484         ext4_handle_error(sb);
 485 }
 486
 487 void ext4_error_inode(struct inode *inode, const char *function,
 488                       unsigned int line, ext4_fsblk_t block,
 489                       const char *fmt, ...)
 490 {
 491         va_list args;
 492         struct va_format vaf;
 493         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 494
 495         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 496         es->s_last_error_block = cpu_to_le64(block);
 497         save_error_info(inode->i_sb, function, line);
 498         va_start(args, fmt);
 499         vaf.fmt = fmt;
 500         vaf.va = &args;
 501         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 502                inode->i_sb->s_id, function, line, inode->i_ino);
 503         if (block)
 504                 printk(KERN_CONT "block %llu: ", block);
 505         printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
 506         va_end(args);
 507
 508         ext4_handle_error(inode->i_sb);
 509 }
 510
 511 void ext4_error_file(struct file *file, const char *function,
 512                      unsigned int line, ext4_fsblk_t block,
 513                      const char *fmt, ...)
 514 {
 515         va_list args;
 516         struct va_format vaf;
 517         struct ext4_super_block *es;
 518         struct inode *inode = file->f_dentry->d_inode;
 519         char pathname[80], *path;
 520
 521         es = EXT4_SB(inode->i_sb)->s_es;
 522         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 523         save_error_info(inode->i_sb, function, line);
 524         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 525         if (IS_ERR(path))
 526                 path = "(unknown)";
 527         printk(KERN_CRIT
 528                "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 529                inode->i_sb->s_id, function, line, inode->i_ino);
 530         if (block)
 531                 printk(KERN_CONT "block %llu: ", block);
 532         va_start(args, fmt);
 533         vaf.fmt = fmt;
 534         vaf.va = &args;
 535         printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
 536         va_end(args);
 537
 538         ext4_handle_error(inode->i_sb);
 539 }
 540
 541 static const char *ext4_decode_error(struct super_block *sb, int errno,
 542                                      char nbuf[16])
 543 {
 544         char *errstr = NULL;
 545
 546         switch (errno) {
 547         case -EIO:
 548                 errstr = "IO failure";
 549                 break;
 550         case -ENOMEM:
 551                 errstr = "Out of memory";
 552                 break;
 553         case -EROFS:
 554                 if (!sb || (EXT4_SB(sb)->s_journal &&
 555                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 556                         errstr = "Journal has aborted";
 557                 else
 558                         errstr = "Readonly filesystem";
 559                 break;
 560         default:
 561                 /* If the caller passed in an extra buffer for unknown
 562                  * errors, textualise them now.  Else we just return
 563                  * NULL. */
 564                 if (nbuf) {
 565                         /* Check for truncated error codes... */
 566                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 567                                 errstr = nbuf;
 568                 }
 569                 break;
 570         }
 571
 572         return errstr;
 573 }
 574
 575 /* __ext4_std_error decodes expected errors from journaling functions
 576  * automatically and invokes the appropriate error response.  */
 577
 578 void __ext4_std_error(struct super_block *sb, const char *function,
 579                       unsigned int line, int errno)
 580 {
 581         char nbuf[16];
 582         const char *errstr;
 583
 584         /* Special case: if the error is EROFS, and we're not already
 585          * inside a transaction, then there's really no point in logging
 586          * an error. */
 587         if (errno == -EROFS && journal_current_handle() == NULL &&
 588             (sb->s_flags & MS_RDONLY))
 589                 return;
 590
 591         errstr = ext4_decode_error(sb, errno, nbuf);
 592         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 593                sb->s_id, function, line, errstr);
 594         save_error_info(sb, function, line);
 595
 596         ext4_handle_error(sb);
 597 }
 598
 599 /*
 600  * ext4_abort is a much stronger failure handler than ext4_error.  The
 601  * abort function may be used to deal with unrecoverable failures such
 602  * as journal IO errors or ENOMEM at a critical moment in log management.
 603  *
 604  * We unconditionally force the filesystem into an ABORT|READONLY state,
 605  * unless the error response on the fs has been set to panic in which
 606  * case we take the easy way out and panic immediately.
 607  */
 608
 609 void __ext4_abort(struct super_block *sb, const char *function,
 610                 unsigned int line, const char *fmt, ...)
 611 {
 612         va_list args;
 613
 614         save_error_info(sb, function, line);
 615         va_start(args, fmt);
 616         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 617                function, line);
 618         vprintk(fmt, args);
 619         printk("\n");
 620         va_end(args);
 621
 622         if ((sb->s_flags & MS_RDONLY) == 0) {
 623                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 624                 sb->s_flags |= MS_RDONLY;
 625                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 626                 if (EXT4_SB(sb)->s_journal)
 627                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 628                 save_error_info(sb, function, line);
 629         }
 630         if (test_opt(sb, ERRORS_PANIC))
 631                 panic("EXT4-fs panic from previous error\n");
 632 }
 633
 634 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 635 {
 636         struct va_format vaf;
 637         va_list args;
 638
 639         va_start(args, fmt);
 640         vaf.fmt = fmt;
 641         vaf.va = &args;
 642         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 643         va_end(args);
 644 }
 645
 646 void __ext4_warning(struct super_block *sb, const char *function,
 647                     unsigned int line, const char *fmt, ...)
 648 {
 649         struct va_format vaf;
 650         va_list args;
 651
 652         va_start(args, fmt);
 653         vaf.fmt = fmt;
 654         vaf.va = &args;
 655         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 656                sb->s_id, function, line, &vaf);
 657         va_end(args);
 658 }
 659
 660 void __ext4_grp_locked_error(const char *function, unsigned int line,
 661                              struct super_block *sb, ext4_group_t grp,
 662                              unsigned long ino, ext4_fsblk_t block,
 663                              const char *fmt, ...)
 664 __releases(bitlock)
 665 __acquires(bitlock)
 666 {
 667         struct va_format vaf;
 668         va_list args;
 669         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 670
 671         es->s_last_error_ino = cpu_to_le32(ino);
 672         es->s_last_error_block = cpu_to_le64(block);
 673         __save_error_info(sb, function, line);
 674
 675         va_start(args, fmt);
 676
 677         vaf.fmt = fmt;
 678         vaf.va = &args;
 679         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 680                sb->s_id, function, line, grp);
 681         if (ino)
 682                 printk(KERN_CONT "inode %lu: ", ino);
 683         if (block)
 684                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 685         printk(KERN_CONT "%pV\n", &vaf);
 686         va_end(args);
 687
 688         if (test_opt(sb, ERRORS_CONT)) {
 689                 ext4_commit_super(sb, 0);
 690                 return;
 691         }
 692
 693         ext4_unlock_group(sb, grp);
 694         ext4_handle_error(sb);
 695         /*
 696          * We only get here in the ERRORS_RO case; relocking the group
 697          * may be dangerous, but nothing bad will happen since the
 698          * filesystem will have already been marked read/only and the
 699          * journal has been aborted.  We return 1 as a hint to callers
 700          * who might what to use the return value from
 701          * ext4_grp_locked_error() to distinguish between the
 702          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 703          * aggressively from the ext4 function in question, with a
 704          * more appropriate error code.
 705          */
 706         ext4_lock_group(sb, grp);
 707         return;
 708 }
 709
 710 void ext4_update_dynamic_rev(struct super_block *sb)
 711 {
 712         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 713
 714         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 715                 return;
 716
 717         ext4_warning(sb,
 718                      "updating to rev %d because of new feature flag, "
 719                      "running e2fsck is recommended",
 720                      EXT4_DYNAMIC_REV);
 721
 722         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 723         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 724         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 725         /* leave es->s_feature_*compat flags alone */
 726         /* es->s_uuid will be set by e2fsck if empty */
 727
 728         /*
 729          * The rest of the superblock fields should be zero, and if not it
 730          * means they are likely already in use, so leave them alone.  We
 731          * can leave it up to e2fsck to clean up any inconsistencies there.
 732          */
 733 }
 734
 735 /*
 736  * Open the external journal device
 737  */
 738 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 739 {
 740         struct block_device *bdev;
 741         char b[BDEVNAME_SIZE];
 742
 743         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 744         if (IS_ERR(bdev))
 745                 goto fail;
 746         return bdev;
 747
 748 fail:
 749         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 750                         __bdevname(dev, b), PTR_ERR(bdev));
 751         return NULL;
 752 }
 753
 754 /*
 755  * Release the journal device
 756  */
 757 static int ext4_blkdev_put(struct block_device *bdev)
 758 {
 759         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 760 }
 761
 762 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 763 {
 764         struct block_device *bdev;
 765         int ret = -ENODEV;
 766
 767         bdev = sbi->journal_bdev;
 768         if (bdev) {
 769                 ret = ext4_blkdev_put(bdev);
 770                 sbi->journal_bdev = NULL;
 771         }
 772         return ret;
 773 }
 774
 775 static inline struct inode *orphan_list_entry(struct list_head *l)
 776 {
 777         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 778 }
 779
 780 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 781 {
 782         struct list_head *l;
 783
 784         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 785                  le32_to_cpu(sbi->s_es->s_last_orphan));
 786
 787         printk(KERN_ERR "sb_info orphan list:\n");
 788         list_for_each(l, &sbi->s_orphan) {
 789                 struct inode *inode = orphan_list_entry(l);
 790                 printk(KERN_ERR "  "
 791                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 792                        inode->i_sb->s_id, inode->i_ino, inode,
 793                        inode->i_mode, inode->i_nlink,
 794                        NEXT_ORPHAN(inode));
 795         }
 796 }
 797
 798 static void ext4_put_super(struct super_block *sb)
 799 {
 800         struct ext4_sb_info *sbi = EXT4_SB(sb);
 801         struct ext4_super_block *es = sbi->s_es;
 802         int i, err;
 803
 804         ext4_unregister_li_request(sb);
 805         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 806
 807         flush_workqueue(sbi->dio_unwritten_wq);
 808         destroy_workqueue(sbi->dio_unwritten_wq);
 809
 810         lock_super(sb);
 811         if (sb->s_dirt)
 812                 ext4_commit_super(sb, 1);
 813
 814         if (sbi->s_journal) {
 815                 err = jbd2_journal_destroy(sbi->s_journal);
 816                 sbi->s_journal = NULL;
 817                 if (err < 0)
 818                         ext4_abort(sb, "Couldn't clean up the journal");
 819         }
 820
 821         del_timer(&sbi->s_err_report);
 822         ext4_release_system_zone(sb);
 823         ext4_mb_release(sb);
 824         ext4_ext_release(sb);
 825         ext4_xattr_put_super(sb);
 826
 827         if (!(sb->s_flags & MS_RDONLY)) {
 828                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 829                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 830                 ext4_commit_super(sb, 1);
 831         }
 832         if (sbi->s_proc) {
 833                 remove_proc_entry(sb->s_id, ext4_proc_root);
 834         }
 835         kobject_del(&sbi->s_kobj);
 836
 837         for (i = 0; i < sbi->s_gdb_count; i++)
 838                 brelse(sbi->s_group_desc[i]);
 839         ext4_kvfree(sbi->s_group_desc);
 840         ext4_kvfree(sbi->s_flex_groups);
 841         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 842         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 843         percpu_counter_destroy(&sbi->s_dirs_counter);
 844         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 845         brelse(sbi->s_sbh);
 846 #ifdef CONFIG_QUOTA
 847         for (i = 0; i < MAXQUOTAS; i++)
 848                 kfree(sbi->s_qf_names[i]);
 849 #endif
 850
 851         /* Debugging code just in case the in-memory inode orphan list
 852          * isn't empty.  The on-disk one can be non-empty if we've
 853          * detected an error and taken the fs readonly, but the
 854          * in-memory list had better be clean by this point. */
 855         if (!list_empty(&sbi->s_orphan))
 856                 dump_orphan_list(sb, sbi);
 857         J_ASSERT(list_empty(&sbi->s_orphan));
 858
 859         invalidate_bdev(sb->s_bdev);
 860         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 861                 /*
 862                  * Invalidate the journal device's buffers.  We don't want them
 863                  * floating about in memory - the physical journal device may
 864                  * hotswapped, and it breaks the `ro-after' testing code.
 865                  */
 866                 sync_blockdev(sbi->journal_bdev);
 867                 invalidate_bdev(sbi->journal_bdev);
 868                 ext4_blkdev_remove(sbi);
 869         }
 870         if (sbi->s_mmp_tsk)
 871                 kthread_stop(sbi->s_mmp_tsk);
 872         sb->s_fs_info = NULL;
 873         /*
 874          * Now that we are completely done shutting down the
 875          * superblock, we need to actually destroy the kobject.
 876          */
 877         unlock_super(sb);
 878         kobject_put(&sbi->s_kobj);
 879         wait_for_completion(&sbi->s_kobj_unregister);
 880         kfree(sbi->s_blockgroup_lock);
 881         kfree(sbi);
 882 }
 883
 884 static struct kmem_cache *ext4_inode_cachep;
 885
 886 /*
 887  * Called inside transaction, so use GFP_NOFS
 888  */
 889 static struct inode *ext4_alloc_inode(struct super_block *sb)
 890 {
 891         struct ext4_inode_info *ei;
 892
 893         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 894         if (!ei)
 895                 return NULL;
 896
 897         ei->vfs_inode.i_version = 1;
 898         ei->vfs_inode.i_data.writeback_index = 0;
 899         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 900         INIT_LIST_HEAD(&ei->i_prealloc_list);
 901         spin_lock_init(&ei->i_prealloc_lock);
 902         ei->i_reserved_data_blocks = 0;
 903         ei->i_reserved_meta_blocks = 0;
 904         ei->i_allocated_meta_blocks = 0;
 905         ei->i_da_metadata_calc_len = 0;
 906         spin_lock_init(&(ei->i_block_reservation_lock));
 907 #ifdef CONFIG_QUOTA
 908         ei->i_reserved_quota = 0;
 909 #endif
 910         ei->jinode = NULL;
 911         INIT_LIST_HEAD(&ei->i_completed_io_list);
 912         spin_lock_init(&ei->i_completed_io_lock);
 913         ei->cur_aio_dio = NULL;
 914         ei->i_sync_tid = 0;
 915         ei->i_datasync_tid = 0;
 916         atomic_set(&ei->i_ioend_count, 0);
 917         atomic_set(&ei->i_aiodio_unwritten, 0);
 918
 919         return &ei->vfs_inode;
 920 }
 921
 922 static int ext4_drop_inode(struct inode *inode)
 923 {
 924         int drop = generic_drop_inode(inode);
 925
 926         trace_ext4_drop_inode(inode, drop);
 927         return drop;
 928 }
 929
 930 static void ext4_i_callback(struct rcu_head *head)
 931 {
 932         struct inode *inode = container_of(head, struct inode, i_rcu);
 933         INIT_LIST_HEAD(&inode->i_dentry);
 934         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 935 }
 936
 937 static void ext4_destroy_inode(struct inode *inode)
 938 {
 939         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 940                 ext4_msg(inode->i_sb, KERN_ERR,
 941                          "Inode %lu (%p): orphan list check failed!",
 942                          inode->i_ino, EXT4_I(inode));
 943                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 944                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 945                                 true);
 946                 dump_stack();
 947         }
 948         call_rcu(&inode->i_rcu, ext4_i_callback);
 949 }
 950
 951 static void init_once(void *foo)
 952 {
 953         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 954
 955         INIT_LIST_HEAD(&ei->i_orphan);
 956 #ifdef CONFIG_EXT4_FS_XATTR
 957         init_rwsem(&ei->xattr_sem);
 958 #endif
 959         init_rwsem(&ei->i_data_sem);
 960         inode_init_once(&ei->vfs_inode);
 961 }
 962
 963 static int init_inodecache(void)
 964 {
 965         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 966                                              sizeof(struct ext4_inode_info),
 967                                              0, (SLAB_RECLAIM_ACCOUNT|
 968                                                 SLAB_MEM_SPREAD),
 969                                              init_once);
 970         if (ext4_inode_cachep == NULL)
 971                 return -ENOMEM;
 972         return 0;
 973 }
 974
 975 static void destroy_inodecache(void)
 976 {
 977         kmem_cache_destroy(ext4_inode_cachep);
 978 }
 979
 980 void ext4_clear_inode(struct inode *inode)
 981 {
 982         invalidate_inode_buffers(inode);
 983         end_writeback(inode);
 984         dquot_drop(inode);
 985         ext4_discard_preallocations(inode);
 986         if (EXT4_I(inode)->jinode) {
 987                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 988                                                EXT4_I(inode)->jinode);
 989                 jbd2_free_inode(EXT4_I(inode)->jinode);
 990                 EXT4_I(inode)->jinode = NULL;
 991         }
 992 }
 993
 994 static inline void ext4_show_quota_options(struct seq_file *seq,
 995                                            struct super_block *sb)
 996 {
 997 #if defined(CONFIG_QUOTA)
 998         struct ext4_sb_info *sbi = EXT4_SB(sb);
 999
1000         if (sbi->s_jquota_fmt) {
1001                 char *fmtname = "";
1002
1003                 switch (sbi->s_jquota_fmt) {
1004                 case QFMT_VFS_OLD:
1005                         fmtname = "vfsold";
1006                         break;
1007                 case QFMT_VFS_V0:
1008                         fmtname = "vfsv0";
1009                         break;
1010                 case QFMT_VFS_V1:
1011                         fmtname = "vfsv1";
1012                         break;
1013                 }
1014                 seq_printf(seq, ",jqfmt=%s", fmtname);
1015         }
1016
1017         if (sbi->s_qf_names[USRQUOTA])
1018                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1019
1020         if (sbi->s_qf_names[GRPQUOTA])
1021                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1022
1023         if (test_opt(sb, USRQUOTA))
1024                 seq_puts(seq, ",usrquota");
1025
1026         if (test_opt(sb, GRPQUOTA))
1027                 seq_puts(seq, ",grpquota");
1028 #endif
1029 }
1030
1031 /*
1032  * Show an option if
1033  *  - it's set to a non-default value OR
1034  *  - if the per-sb default is different from the global default
1035  */
1036 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
1037 {
1038         int def_errors;
1039         unsigned long def_mount_opts;
1040         struct super_block *sb = vfs->mnt_sb;
1041         struct ext4_sb_info *sbi = EXT4_SB(sb);
1042         struct ext4_super_block *es = sbi->s_es;
1043
1044         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1045         def_errors     = le16_to_cpu(es->s_errors);
1046
1047         if (sbi->s_sb_block != 1)
1048                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
1049         if (test_opt(sb, MINIX_DF))
1050                 seq_puts(seq, ",minixdf");
1051         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
1052                 seq_puts(seq, ",grpid");
1053         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
1054                 seq_puts(seq, ",nogrpid");
1055         if (sbi->s_resuid != EXT4_DEF_RESUID ||
1056             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
1057                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
1058         }
1059         if (sbi->s_resgid != EXT4_DEF_RESGID ||
1060             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
1061                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
1062         }
1063         if (test_opt(sb, ERRORS_RO)) {
1064                 if (def_errors == EXT4_ERRORS_PANIC ||
1065                     def_errors == EXT4_ERRORS_CONTINUE) {
1066                         seq_puts(seq, ",errors=remount-ro");
1067                 }
1068         }
1069         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1070                 seq_puts(seq, ",errors=continue");
1071         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1072                 seq_puts(seq, ",errors=panic");
1073         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
1074                 seq_puts(seq, ",nouid32");
1075         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
1076                 seq_puts(seq, ",debug");
1077 #ifdef CONFIG_EXT4_FS_XATTR
1078         if (test_opt(sb, XATTR_USER))
1079                 seq_puts(seq, ",user_xattr");
1080         if (!test_opt(sb, XATTR_USER))
1081                 seq_puts(seq, ",nouser_xattr");
1082 #endif
1083 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1084         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1085                 seq_puts(seq, ",acl");
1086         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1087                 seq_puts(seq, ",noacl");
1088 #endif
1089         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1090                 seq_printf(seq, ",commit=%u",
1091                            (unsigned) (sbi->s_commit_interval / HZ));
1092         }
1093         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1094                 seq_printf(seq, ",min_batch_time=%u",
1095                            (unsigned) sbi->s_min_batch_time);
1096         }
1097         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1098                 seq_printf(seq, ",max_batch_time=%u",
1099                            (unsigned) sbi->s_min_batch_time);
1100         }
1101
1102         /*
1103          * We're changing the default of barrier mount option, so
1104          * let's always display its mount state so it's clear what its
1105          * status is.
1106          */
1107         seq_puts(seq, ",barrier=");
1108         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1109         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1110                 seq_puts(seq, ",journal_async_commit");
1111         else if (test_opt(sb, JOURNAL_CHECKSUM))
1112                 seq_puts(seq, ",journal_checksum");
1113         if (test_opt(sb, I_VERSION))
1114                 seq_puts(seq, ",i_version");
1115         if (!test_opt(sb, DELALLOC) &&
1116             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1117                 seq_puts(seq, ",nodelalloc");
1118
1119         if (!test_opt(sb, MBLK_IO_SUBMIT))
1120                 seq_puts(seq, ",nomblk_io_submit");
1121         if (sbi->s_stripe)
1122                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1123         /*
1124          * journal mode get enabled in different ways
1125          * So just print the value even if we didn't specify it
1126          */
1127         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1128                 seq_puts(seq, ",data=journal");
1129         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1130                 seq_puts(seq, ",data=ordered");
1131         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1132                 seq_puts(seq, ",data=writeback");
1133
1134         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1135                 seq_printf(seq, ",inode_readahead_blks=%u",
1136                            sbi->s_inode_readahead_blks);
1137
1138         if (test_opt(sb, DATA_ERR_ABORT))
1139                 seq_puts(seq, ",data_err=abort");
1140
1141         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1142                 seq_puts(seq, ",noauto_da_alloc");
1143
1144         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1145                 seq_puts(seq, ",discard");
1146
1147         if (test_opt(sb, NOLOAD))
1148                 seq_puts(seq, ",norecovery");
1149
1150         if (test_opt(sb, DIOREAD_NOLOCK))
1151                 seq_puts(seq, ",dioread_nolock");
1152
1153         if (test_opt(sb, BLOCK_VALIDITY) &&
1154             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1155                 seq_puts(seq, ",block_validity");
1156
1157         if (!test_opt(sb, INIT_INODE_TABLE))
1158                 seq_puts(seq, ",noinit_itable");
1159         else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
1160                 seq_printf(seq, ",init_itable=%u",
1161                            (unsigned) sbi->s_li_wait_mult);
1162
1163         ext4_show_quota_options(seq, sb);
1164
1165         return 0;
1166 }
1167
1168 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1169                                         u64 ino, u32 generation)
1170 {
1171         struct inode *inode;
1172
1173         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1174                 return ERR_PTR(-ESTALE);
1175         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1176                 return ERR_PTR(-ESTALE);
1177
1178         /* iget isn't really right if the inode is currently unallocated!!
1179          *
1180          * ext4_read_inode will return a bad_inode if the inode had been
1181          * deleted, so we should be safe.
1182          *
1183          * Currently we don't know the generation for parent directory, so
1184          * a generation of 0 means "accept any"
1185          */
1186         inode = ext4_iget(sb, ino);
1187         if (IS_ERR(inode))
1188                 return ERR_CAST(inode);
1189         if (generation && inode->i_generation != generation) {
1190                 iput(inode);
1191                 return ERR_PTR(-ESTALE);
1192         }
1193
1194         return inode;
1195 }
1196
1197 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1198                                         int fh_len, int fh_type)
1199 {
1200         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1201                                     ext4_nfs_get_inode);
1202 }
1203
1204 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1205                                         int fh_len, int fh_type)
1206 {
1207         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1208                                     ext4_nfs_get_inode);
1209 }
1210
1211 /*
1212  * Try to release metadata pages (indirect blocks, directories) which are
1213  * mapped via the block device.  Since these pages could have journal heads
1214  * which would prevent try_to_free_buffers() from freeing them, we must use
1215  * jbd2 layer's try_to_free_buffers() function to release them.
1216  */
1217 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1218                                  gfp_t wait)
1219 {
1220         journal_t *journal = EXT4_SB(sb)->s_journal;
1221
1222         WARN_ON(PageChecked(page));
1223         if (!page_has_buffers(page))
1224                 return 0;
1225         if (journal)
1226                 return jbd2_journal_try_to_free_buffers(journal, page,
1227                                                         wait & ~__GFP_WAIT);
1228         return try_to_free_buffers(page);
1229 }
1230
1231 #ifdef CONFIG_QUOTA
1232 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1233 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1234
1235 static int ext4_write_dquot(struct dquot *dquot);
1236 static int ext4_acquire_dquot(struct dquot *dquot);
1237 static int ext4_release_dquot(struct dquot *dquot);
1238 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1239 static int ext4_write_info(struct super_block *sb, int type);
1240 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1241                          struct path *path);
1242 static int ext4_quota_off(struct super_block *sb, int type);
1243 static int ext4_quota_on_mount(struct super_block *sb, int type);
1244 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1245                                size_t len, loff_t off);
1246 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1247                                 const char *data, size_t len, loff_t off);
1248
1249 static const struct dquot_operations ext4_quota_operations = {
1250         .get_reserved_space = ext4_get_reserved_space,
1251         .write_dquot    = ext4_write_dquot,
1252         .acquire_dquot  = ext4_acquire_dquot,
1253         .release_dquot  = ext4_release_dquot,
1254         .mark_dirty     = ext4_mark_dquot_dirty,
1255         .write_info     = ext4_write_info,
1256         .alloc_dquot    = dquot_alloc,
1257         .destroy_dquot  = dquot_destroy,
1258 };
1259
1260 static const struct quotactl_ops ext4_qctl_operations = {
1261         .quota_on       = ext4_quota_on,
1262         .quota_off      = ext4_quota_off,
1263         .quota_sync     = dquot_quota_sync,
1264         .get_info       = dquot_get_dqinfo,
1265         .set_info       = dquot_set_dqinfo,
1266         .get_dqblk      = dquot_get_dqblk,
1267         .set_dqblk      = dquot_set_dqblk
1268 };
1269 #endif
1270
1271 static const struct super_operations ext4_sops = {
1272         .alloc_inode    = ext4_alloc_inode,
1273         .destroy_inode  = ext4_destroy_inode,
1274         .write_inode    = ext4_write_inode,
1275         .dirty_inode    = ext4_dirty_inode,
1276         .drop_inode     = ext4_drop_inode,
1277         .evict_inode    = ext4_evict_inode,
1278         .put_super      = ext4_put_super,
1279         .sync_fs        = ext4_sync_fs,
1280         .freeze_fs      = ext4_freeze,
1281         .unfreeze_fs    = ext4_unfreeze,
1282         .statfs         = ext4_statfs,
1283         .remount_fs     = ext4_remount,
1284         .show_options   = ext4_show_options,
1285 #ifdef CONFIG_QUOTA
1286         .quota_read     = ext4_quota_read,
1287         .quota_write    = ext4_quota_write,
1288 #endif
1289         .bdev_try_to_free_page = bdev_try_to_free_page,
1290 };
1291
1292 static const struct super_operations ext4_nojournal_sops = {
1293         .alloc_inode    = ext4_alloc_inode,
1294         .destroy_inode  = ext4_destroy_inode,
1295         .write_inode    = ext4_write_inode,
1296         .dirty_inode    = ext4_dirty_inode,
1297         .drop_inode     = ext4_drop_inode,
1298         .evict_inode    = ext4_evict_inode,
1299         .write_super    = ext4_write_super,
1300         .put_super      = ext4_put_super,
1301         .statfs         = ext4_statfs,
1302         .remount_fs     = ext4_remount,
1303         .show_options   = ext4_show_options,
1304 #ifdef CONFIG_QUOTA
1305         .quota_read     = ext4_quota_read,
1306         .quota_write    = ext4_quota_write,
1307 #endif
1308         .bdev_try_to_free_page = bdev_try_to_free_page,
1309 };
1310
1311 static const struct export_operations ext4_export_ops = {
1312         .fh_to_dentry = ext4_fh_to_dentry,
1313         .fh_to_parent = ext4_fh_to_parent,
1314         .get_parent = ext4_get_parent,
1315 };
1316
1317 enum {
1318         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1319         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1320         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1321         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1322         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1323         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1324         Opt_journal_update, Opt_journal_dev,
1325         Opt_journal_checksum, Opt_journal_async_commit,
1326         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1327         Opt_data_err_abort, Opt_data_err_ignore,
1328         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1329         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1330         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1331         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1332         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1333         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1334         Opt_inode_readahead_blks, Opt_journal_ioprio,
1335         Opt_dioread_nolock, Opt_dioread_lock,
1336         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1337 };
1338
1339 static const match_table_t tokens = {
1340         {Opt_bsd_df, "bsddf"},
1341         {Opt_minix_df, "minixdf"},
1342         {Opt_grpid, "grpid"},
1343         {Opt_grpid, "bsdgroups"},
1344         {Opt_nogrpid, "nogrpid"},
1345         {Opt_nogrpid, "sysvgroups"},
1346         {Opt_resgid, "resgid=%u"},
1347         {Opt_resuid, "resuid=%u"},
1348         {Opt_sb, "sb=%u"},
1349         {Opt_err_cont, "errors=continue"},
1350         {Opt_err_panic, "errors=panic"},
1351         {Opt_err_ro, "errors=remount-ro"},
1352         {Opt_nouid32, "nouid32"},
1353         {Opt_debug, "debug"},
1354         {Opt_oldalloc, "oldalloc"},
1355         {Opt_orlov, "orlov"},
1356         {Opt_user_xattr, "user_xattr"},
1357         {Opt_nouser_xattr, "nouser_xattr"},
1358         {Opt_acl, "acl"},
1359         {Opt_noacl, "noacl"},
1360         {Opt_noload, "noload"},
1361         {Opt_noload, "norecovery"},
1362         {Opt_nobh, "nobh"},
1363         {Opt_bh, "bh"},
1364         {Opt_commit, "commit=%u"},
1365         {Opt_min_batch_time, "min_batch_time=%u"},
1366         {Opt_max_batch_time, "max_batch_time=%u"},
1367         {Opt_journal_update, "journal=update"},
1368         {Opt_journal_dev, "journal_dev=%u"},
1369         {Opt_journal_checksum, "journal_checksum"},
1370         {Opt_journal_async_commit, "journal_async_commit"},
1371         {Opt_abort, "abort"},
1372         {Opt_data_journal, "data=journal"},
1373         {Opt_data_ordered, "data=ordered"},
1374         {Opt_data_writeback, "data=writeback"},
1375         {Opt_data_err_abort, "data_err=abort"},
1376         {Opt_data_err_ignore, "data_err=ignore"},
1377         {Opt_offusrjquota, "usrjquota="},
1378         {Opt_usrjquota, "usrjquota=%s"},
1379         {Opt_offgrpjquota, "grpjquota="},
1380         {Opt_grpjquota, "grpjquota=%s"},
1381         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1382         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1383         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1384         {Opt_grpquota, "grpquota"},
1385         {Opt_noquota, "noquota"},
1386         {Opt_quota, "quota"},
1387         {Opt_usrquota, "usrquota"},
1388         {Opt_barrier, "barrier=%u"},
1389         {Opt_barrier, "barrier"},
1390         {Opt_nobarrier, "nobarrier"},
1391         {Opt_i_version, "i_version"},
1392         {Opt_stripe, "stripe=%u"},
1393         {Opt_resize, "resize"},
1394         {Opt_delalloc, "delalloc"},
1395         {Opt_nodelalloc, "nodelalloc"},
1396         {Opt_mblk_io_submit, "mblk_io_submit"},
1397         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1398         {Opt_block_validity, "block_validity"},
1399         {Opt_noblock_validity, "noblock_validity"},
1400         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1401         {Opt_journal_ioprio, "journal_ioprio=%u"},
1402         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1403         {Opt_auto_da_alloc, "auto_da_alloc"},
1404         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1405         {Opt_dioread_nolock, "dioread_nolock"},
1406         {Opt_dioread_lock, "dioread_lock"},
1407         {Opt_discard, "discard"},
1408         {Opt_nodiscard, "nodiscard"},
1409         {Opt_init_itable, "init_itable=%u"},
1410         {Opt_init_itable, "init_itable"},
1411         {Opt_noinit_itable, "noinit_itable"},
1412         {Opt_err, NULL},
1413 };
1414
1415 static ext4_fsblk_t get_sb_block(void **data)
1416 {
1417         ext4_fsblk_t    sb_block;
1418         char            *options = (char *) *data;
1419
1420         if (!options || strncmp(options, "sb=", 3) != 0)
1421                 return 1;       /* Default location */
1422
1423         options += 3;
1424         /* TODO: use simple_strtoll with >32bit ext4 */
1425         sb_block = simple_strtoul(options, &options, 0);
1426         if (*options && *options != ',') {
1427                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1428                        (char *) *data);
1429                 return 1;
1430         }
1431         if (*options == ',')
1432                 options++;
1433         *data = (void *) options;
1434
1435         return sb_block;
1436 }
1437
1438 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1439 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1440         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1441
1442 #ifdef CONFIG_QUOTA
1443 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1444 {
1445         struct ext4_sb_info *sbi = EXT4_SB(sb);
1446         char *qname;
1447
1448         if (sb_any_quota_loaded(sb) &&
1449                 !sbi->s_qf_names[qtype]) {
1450                 ext4_msg(sb, KERN_ERR,
1451                         "Cannot change journaled "
1452                         "quota options when quota turned on");
1453                 return 0;
1454         }
1455         qname = match_strdup(args);
1456         if (!qname) {
1457                 ext4_msg(sb, KERN_ERR,
1458                         "Not enough memory for storing quotafile name");
1459                 return 0;
1460         }
1461         if (sbi->s_qf_names[qtype] &&
1462                 strcmp(sbi->s_qf_names[qtype], qname)) {
1463                 ext4_msg(sb, KERN_ERR,
1464                         "%s quota file already specified", QTYPE2NAME(qtype));
1465                 kfree(qname);
1466                 return 0;
1467         }
1468         sbi->s_qf_names[qtype] = qname;
1469         if (strchr(sbi->s_qf_names[qtype], '/')) {
1470                 ext4_msg(sb, KERN_ERR,
1471                         "quotafile must be on filesystem root");
1472                 kfree(sbi->s_qf_names[qtype]);
1473                 sbi->s_qf_names[qtype] = NULL;
1474                 return 0;
1475         }
1476         set_opt(sb, QUOTA);
1477         return 1;
1478 }
1479
1480 static int clear_qf_name(struct super_block *sb, int qtype)
1481 {
1482
1483         struct ext4_sb_info *sbi = EXT4_SB(sb);
1484
1485         if (sb_any_quota_loaded(sb) &&
1486                 sbi->s_qf_names[qtype]) {
1487                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1488                         " when quota turned on");
1489                 return 0;
1490         }
1491         /*
1492          * The space will be released later when all options are confirmed
1493          * to be correct
1494          */
1495         sbi->s_qf_names[qtype] = NULL;
1496         return 1;
1497 }
1498 #endif
1499
1500 static int parse_options(char *options, struct super_block *sb,
1501                          unsigned long *journal_devnum,
1502                          unsigned int *journal_ioprio,
1503                          ext4_fsblk_t *n_blocks_count, int is_remount)
1504 {
1505         struct ext4_sb_info *sbi = EXT4_SB(sb);
1506         char *p;
1507         substring_t args[MAX_OPT_ARGS];
1508         int data_opt = 0;
1509         int option;
1510 #ifdef CONFIG_QUOTA
1511         int qfmt;
1512 #endif
1513
1514         if (!options)
1515                 return 1;
1516
1517         while ((p = strsep(&options, ",")) != NULL) {
1518                 int token;
1519                 if (!*p)
1520                         continue;
1521
1522                 /*
1523                  * Initialize args struct so we know whether arg was
1524                  * found; some options take optional arguments.
1525                  */
1526                 args[0].to = args[0].from = NULL;
1527                 token = match_token(p, tokens, args);
1528                 switch (token) {
1529                 case Opt_bsd_df:
1530                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1531                         clear_opt(sb, MINIX_DF);
1532                         break;
1533                 case Opt_minix_df:
1534                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1535                         set_opt(sb, MINIX_DF);
1536
1537                         break;
1538                 case Opt_grpid:
1539                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1540                         set_opt(sb, GRPID);
1541
1542                         break;
1543                 case Opt_nogrpid:
1544                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1545                         clear_opt(sb, GRPID);
1546
1547                         break;
1548                 case Opt_resuid:
1549                         if (match_int(&args[0], &option))
1550                                 return 0;
1551                         sbi->s_resuid = option;
1552                         break;
1553                 case Opt_resgid:
1554                         if (match_int(&args[0], &option))
1555                                 return 0;
1556                         sbi->s_resgid = option;
1557                         break;
1558                 case Opt_sb:
1559                         /* handled by get_sb_block() instead of here */
1560                         /* *sb_block = match_int(&args[0]); */
1561                         break;
1562                 case Opt_err_panic:
1563                         clear_opt(sb, ERRORS_CONT);
1564                         clear_opt(sb, ERRORS_RO);
1565                         set_opt(sb, ERRORS_PANIC);
1566                         break;
1567                 case Opt_err_ro:
1568                         clear_opt(sb, ERRORS_CONT);
1569                         clear_opt(sb, ERRORS_PANIC);
1570                         set_opt(sb, ERRORS_RO);
1571                         break;
1572                 case Opt_err_cont:
1573                         clear_opt(sb, ERRORS_RO);
1574                         clear_opt(sb, ERRORS_PANIC);
1575                         set_opt(sb, ERRORS_CONT);
1576                         break;
1577                 case Opt_nouid32:
1578                         set_opt(sb, NO_UID32);
1579                         break;
1580                 case Opt_debug:
1581                         set_opt(sb, DEBUG);
1582                         break;
1583                 case Opt_oldalloc:
1584                         ext4_msg(sb, KERN_WARNING,
1585                                  "Ignoring deprecated oldalloc option");
1586                         break;
1587                 case Opt_orlov:
1588                         ext4_msg(sb, KERN_WARNING,
1589                                  "Ignoring deprecated orlov option");
1590                         break;
1591 #ifdef CONFIG_EXT4_FS_XATTR
1592                 case Opt_user_xattr:
1593                         set_opt(sb, XATTR_USER);
1594                         break;
1595                 case Opt_nouser_xattr:
1596                         clear_opt(sb, XATTR_USER);
1597                         break;
1598 #else
1599                 case Opt_user_xattr:
1600                 case Opt_nouser_xattr:
1601                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1602                         break;
1603 #endif
1604 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1605                 case Opt_acl:
1606                         set_opt(sb, POSIX_ACL);
1607                         break;
1608                 case Opt_noacl:
1609                         clear_opt(sb, POSIX_ACL);
1610                         break;
1611 #else
1612                 case Opt_acl:
1613                 case Opt_noacl:
1614                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1615                         break;
1616 #endif
1617                 case Opt_journal_update:
1618                         /* @@@ FIXME */
1619                         /* Eventually we will want to be able to create
1620                            a journal file here.  For now, only allow the
1621                            user to specify an existing inode to be the
1622                            journal file. */
1623                         if (is_remount) {
1624                                 ext4_msg(sb, KERN_ERR,
1625                                          "Cannot specify journal on remount");
1626                                 return 0;
1627                         }
1628                         set_opt(sb, UPDATE_JOURNAL);
1629                         break;
1630                 case Opt_journal_dev:
1631                         if (is_remount) {
1632                                 ext4_msg(sb, KERN_ERR,
1633                                         "Cannot specify journal on remount");
1634                                 return 0;
1635                         }
1636                         if (match_int(&args[0], &option))
1637                                 return 0;
1638                         *journal_devnum = option;
1639                         break;
1640                 case Opt_journal_checksum:
1641                         set_opt(sb, JOURNAL_CHECKSUM);
1642                         break;
1643                 case Opt_journal_async_commit:
1644                         set_opt(sb, JOURNAL_ASYNC_COMMIT);
1645                         set_opt(sb, JOURNAL_CHECKSUM);
1646                         break;
1647                 case Opt_noload:
1648                         set_opt(sb, NOLOAD);
1649                         break;
1650                 case Opt_commit:
1651                         if (match_int(&args[0], &option))
1652                                 return 0;
1653                         if (option < 0)
1654                                 return 0;
1655                         if (option == 0)
1656                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1657                         sbi->s_commit_interval = HZ * option;
1658                         break;
1659                 case Opt_max_batch_time:
1660                         if (match_int(&args[0], &option))
1661                                 return 0;
1662                         if (option < 0)
1663                                 return 0;
1664                         if (option == 0)
1665                                 option = EXT4_DEF_MAX_BATCH_TIME;
1666                         sbi->s_max_batch_time = option;
1667                         break;
1668                 case Opt_min_batch_time:
1669                         if (match_int(&args[0], &option))
1670                                 return 0;
1671                         if (option < 0)
1672                                 return 0;
1673                         sbi->s_min_batch_time = option;
1674                         break;
1675                 case Opt_data_journal:
1676                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1677                         goto datacheck;
1678                 case Opt_data_ordered:
1679                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1680                         goto datacheck;
1681                 case Opt_data_writeback:
1682                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1683                 datacheck:
1684                         if (is_remount) {
1685                                 if (!sbi->s_journal)
1686                                         ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1687                                 else if (test_opt(sb, DATA_FLAGS) != data_opt) {
1688                                         ext4_msg(sb, KERN_ERR,
1689                                                 "Cannot change data mode on remount");
1690                                         return 0;
1691                                 }
1692                         } else {
1693                                 clear_opt(sb, DATA_FLAGS);
1694                                 sbi->s_mount_opt |= data_opt;
1695                         }
1696                         break;
1697                 case Opt_data_err_abort:
1698                         set_opt(sb, DATA_ERR_ABORT);
1699                         break;
1700                 case Opt_data_err_ignore:
1701                         clear_opt(sb, DATA_ERR_ABORT);
1702                         break;
1703 #ifdef CONFIG_QUOTA
1704                 case Opt_usrjquota:
1705                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1706                                 return 0;
1707                         break;
1708                 case Opt_grpjquota:
1709                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1710                                 return 0;
1711                         break;
1712                 case Opt_offusrjquota:
1713                         if (!clear_qf_name(sb, USRQUOTA))
1714                                 return 0;
1715                         break;
1716                 case Opt_offgrpjquota:
1717                         if (!clear_qf_name(sb, GRPQUOTA))
1718                                 return 0;
1719                         break;
1720
1721                 case Opt_jqfmt_vfsold:
1722                         qfmt = QFMT_VFS_OLD;
1723                         goto set_qf_format;
1724                 case Opt_jqfmt_vfsv0:
1725                         qfmt = QFMT_VFS_V0;
1726                         goto set_qf_format;
1727                 case Opt_jqfmt_vfsv1:
1728                         qfmt = QFMT_VFS_V1;
1729 set_qf_format:
1730                         if (sb_any_quota_loaded(sb) &&
1731                             sbi->s_jquota_fmt != qfmt) {
1732                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1733                                         "journaled quota options when "
1734                                         "quota turned on");
1735                                 return 0;
1736                         }
1737                         sbi->s_jquota_fmt = qfmt;
1738                         break;
1739                 case Opt_quota:
1740                 case Opt_usrquota:
1741                         set_opt(sb, QUOTA);
1742                         set_opt(sb, USRQUOTA);
1743                         break;
1744                 case Opt_grpquota:
1745                         set_opt(sb, QUOTA);
1746                         set_opt(sb, GRPQUOTA);
1747                         break;
1748                 case Opt_noquota:
1749                         if (sb_any_quota_loaded(sb)) {
1750                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1751                                         "options when quota turned on");
1752                                 return 0;
1753                         }
1754                         clear_opt(sb, QUOTA);
1755                         clear_opt(sb, USRQUOTA);
1756                         clear_opt(sb, GRPQUOTA);
1757                         break;
1758 #else
1759                 case Opt_quota:
1760                 case Opt_usrquota:
1761                 case Opt_grpquota:
1762                         ext4_msg(sb, KERN_ERR,
1763                                 "quota options not supported");
1764                         break;
1765                 case Opt_usrjquota:
1766                 case Opt_grpjquota:
1767                 case Opt_offusrjquota:
1768                 case Opt_offgrpjquota:
1769                 case Opt_jqfmt_vfsold:
1770                 case Opt_jqfmt_vfsv0:
1771                 case Opt_jqfmt_vfsv1:
1772                         ext4_msg(sb, KERN_ERR,
1773                                 "journaled quota options not supported");
1774                         break;
1775                 case Opt_noquota:
1776                         break;
1777 #endif
1778                 case Opt_abort:
1779                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1780                         break;
1781                 case Opt_nobarrier:
1782                         clear_opt(sb, BARRIER);
1783                         break;
1784                 case Opt_barrier:
1785                         if (args[0].from) {
1786                                 if (match_int(&args[0], &option))
1787                                         return 0;
1788                         } else
1789                                 option = 1;     /* No argument, default to 1 */
1790                         if (option)
1791                                 set_opt(sb, BARRIER);
1792                         else
1793                                 clear_opt(sb, BARRIER);
1794                         break;
1795                 case Opt_ignore:
1796                         break;
1797                 case Opt_resize:
1798                         if (!is_remount) {
1799                                 ext4_msg(sb, KERN_ERR,
1800                                         "resize option only available "
1801                                         "for remount");
1802                                 return 0;
1803                         }
1804                         if (match_int(&args[0], &option) != 0)
1805                                 return 0;
1806                         *n_blocks_count = option;
1807                         break;
1808                 case Opt_nobh:
1809                         ext4_msg(sb, KERN_WARNING,
1810                                  "Ignoring deprecated nobh option");
1811                         break;
1812                 case Opt_bh:
1813                         ext4_msg(sb, KERN_WARNING,
1814                                  "Ignoring deprecated bh option");
1815                         break;
1816                 case Opt_i_version:
1817                         set_opt(sb, I_VERSION);
1818                         sb->s_flags |= MS_I_VERSION;
1819                         break;
1820                 case Opt_nodelalloc:
1821                         clear_opt(sb, DELALLOC);
1822                         clear_opt2(sb, EXPLICIT_DELALLOC);
1823                         break;
1824                 case Opt_mblk_io_submit:
1825                         set_opt(sb, MBLK_IO_SUBMIT);
1826                         break;
1827                 case Opt_nomblk_io_submit:
1828                         clear_opt(sb, MBLK_IO_SUBMIT);
1829                         break;
1830                 case Opt_stripe:
1831                         if (match_int(&args[0], &option))
1832                                 return 0;
1833                         if (option < 0)
1834                                 return 0;
1835                         sbi->s_stripe = option;
1836                         break;
1837                 case Opt_delalloc:
1838                         set_opt(sb, DELALLOC);
1839                         set_opt2(sb, EXPLICIT_DELALLOC);
1840                         break;
1841                 case Opt_block_validity:
1842                         set_opt(sb, BLOCK_VALIDITY);
1843                         break;
1844                 case Opt_noblock_validity:
1845                         clear_opt(sb, BLOCK_VALIDITY);
1846                         break;
1847                 case Opt_inode_readahead_blks:
1848                         if (match_int(&args[0], &option))
1849                                 return 0;
1850                         if (option < 0 || option > (1 << 30))
1851                                 return 0;
1852                         if (option && !is_power_of_2(option)) {
1853                                 ext4_msg(sb, KERN_ERR,
1854                                          "EXT4-fs: inode_readahead_blks"
1855                                          " must be a power of 2");
1856                                 return 0;
1857                         }
1858                         sbi->s_inode_readahead_blks = option;
1859                         break;
1860                 case Opt_journal_ioprio:
1861                         if (match_int(&args[0], &option))
1862                                 return 0;
1863                         if (option < 0 || option > 7)
1864                                 break;
1865                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1866                                                             option);
1867                         break;
1868                 case Opt_noauto_da_alloc:
1869                         set_opt(sb, NO_AUTO_DA_ALLOC);
1870                         break;
1871                 case Opt_auto_da_alloc:
1872                         if (args[0].from) {
1873                                 if (match_int(&args[0], &option))
1874                                         return 0;
1875                         } else
1876                                 option = 1;     /* No argument, default to 1 */
1877                         if (option)
1878                                 clear_opt(sb, NO_AUTO_DA_ALLOC);
1879                         else
1880                                 set_opt(sb,NO_AUTO_DA_ALLOC);
1881                         break;
1882                 case Opt_discard:
1883                         set_opt(sb, DISCARD);
1884                         break;
1885                 case Opt_nodiscard:
1886                         clear_opt(sb, DISCARD);
1887                         break;
1888                 case Opt_dioread_nolock:
1889                         set_opt(sb, DIOREAD_NOLOCK);
1890                         break;
1891                 case Opt_dioread_lock:
1892                         clear_opt(sb, DIOREAD_NOLOCK);
1893                         break;
1894                 case Opt_init_itable:
1895                         set_opt(sb, INIT_INODE_TABLE);
1896                         if (args[0].from) {
1897                                 if (match_int(&args[0], &option))
1898                                         return 0;
1899                         } else
1900                                 option = EXT4_DEF_LI_WAIT_MULT;
1901                         if (option < 0)
1902                                 return 0;
1903                         sbi->s_li_wait_mult = option;
1904                         break;
1905                 case Opt_noinit_itable:
1906                         clear_opt(sb, INIT_INODE_TABLE);
1907                         break;
1908                 default:
1909                         ext4_msg(sb, KERN_ERR,
1910                                "Unrecognized mount option \"%s\" "
1911                                "or missing value", p);
1912                         return 0;
1913                 }
1914         }
1915 #ifdef CONFIG_QUOTA
1916         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1917                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1918                         clear_opt(sb, USRQUOTA);
1919
1920                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1921                         clear_opt(sb, GRPQUOTA);
1922
1923                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1924                         ext4_msg(sb, KERN_ERR, "old and new quota "
1925                                         "format mixing");
1926                         return 0;
1927                 }
1928
1929                 if (!sbi->s_jquota_fmt) {
1930                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1931                                         "not specified");
1932                         return 0;
1933                 }
1934         } else {
1935                 if (sbi->s_jquota_fmt) {
1936                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1937                                         "specified with no journaling "
1938                                         "enabled");
1939                         return 0;
1940                 }
1941         }
1942 #endif
1943         return 1;
1944 }
1945
1946 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1947                             int read_only)
1948 {
1949         struct ext4_sb_info *sbi = EXT4_SB(sb);
1950         int res = 0;
1951
1952         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1953                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1954                          "forcing read-only mode");
1955                 res = MS_RDONLY;
1956         }
1957         if (read_only)
1958                 goto done;
1959         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1960                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1961                          "running e2fsck is recommended");
1962         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1963                 ext4_msg(sb, KERN_WARNING,
1964                          "warning: mounting fs with errors, "
1965                          "running e2fsck is recommended");
1966         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1967                  le16_to_cpu(es->s_mnt_count) >=
1968                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1969                 ext4_msg(sb, KERN_WARNING,
1970                          "warning: maximal mount count reached, "
1971                          "running e2fsck is recommended");
1972         else if (le32_to_cpu(es->s_checkinterval) &&
1973                 (le32_to_cpu(es->s_lastcheck) +
1974                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1975                 ext4_msg(sb, KERN_WARNING,
1976                          "warning: checktime reached, "
1977                          "running e2fsck is recommended");
1978         if (!sbi->s_journal)
1979                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1980         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1981                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1982         le16_add_cpu(&es->s_mnt_count, 1);
1983         es->s_mtime = cpu_to_le32(get_seconds());
1984         ext4_update_dynamic_rev(sb);
1985         if (sbi->s_journal)
1986                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1987
1988         ext4_commit_super(sb, 1);
1989 done:
1990         if (test_opt(sb, DEBUG))
1991                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1992                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1993                         sb->s_blocksize,
1994                         sbi->s_groups_count,
1995                         EXT4_BLOCKS_PER_GROUP(sb),
1996                         EXT4_INODES_PER_GROUP(sb),
1997                         sbi->s_mount_opt, sbi->s_mount_opt2);
1998
1999         cleancache_init_fs(sb);
2000         return res;
2001 }
2002
2003 static int ext4_fill_flex_info(struct super_block *sb)
2004 {
2005         struct ext4_sb_info *sbi = EXT4_SB(sb);
2006         struct ext4_group_desc *gdp = NULL;
2007         ext4_group_t flex_group_count;
2008         ext4_group_t flex_group;
2009         int groups_per_flex = 0;
2010         size_t size;
2011         int i;
2012
2013         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2014         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
2015
2016         if (groups_per_flex < 2) {
2017                 sbi->s_log_groups_per_flex = 0;
2018                 return 1;
2019         }
2020
2021         /* We allocate both existing and potentially added groups */
2022         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
2023                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
2024                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
2025         size = flex_group_count * sizeof(struct flex_groups);
2026         sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
2027         if (sbi->s_flex_groups == NULL) {
2028                 ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
2029                          flex_group_count);
2030                 goto failed;
2031         }
2032
2033         for (i = 0; i < sbi->s_groups_count; i++) {
2034                 gdp = ext4_get_group_desc(sb, i, NULL);
2035
2036                 flex_group = ext4_flex_group(sbi, i);
2037                 atomic_add(ext4_free_inodes_count(sb, gdp),
2038                            &sbi->s_flex_groups[flex_group].free_inodes);
2039                 atomic_add(ext4_free_group_clusters(sb, gdp),
2040                            &sbi->s_flex_groups[flex_group].free_clusters);
2041                 atomic_add(ext4_used_dirs_count(sb, gdp),
2042                            &sbi->s_flex_groups[flex_group].used_dirs);
2043         }
2044
2045         return 1;
2046 failed:
2047         return 0;
2048 }
2049
2050 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2051                             struct ext4_group_desc *gdp)
2052 {
2053         __u16 crc = 0;
2054
2055         if (sbi->s_es->s_feature_ro_compat &
2056             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
2057                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
2058                 __le32 le_group = cpu_to_le32(block_group);
2059
2060                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2061                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2062                 crc = crc16(crc, (__u8 *)gdp, offset);
2063                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
2064                 /* for checksum of struct ext4_group_desc do the rest...*/
2065                 if ((sbi->s_es->s_feature_incompat &
2066                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2067                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
2068                         crc = crc16(crc, (__u8 *)gdp + offset,
2069                                     le16_to_cpu(sbi->s_es->s_desc_size) -
2070                                         offset);
2071         }
2072
2073         return cpu_to_le16(crc);
2074 }
2075
2076 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2077                                 struct ext4_group_desc *gdp)
2078 {
2079         if ((sbi->s_es->s_feature_ro_compat &
2080              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2081             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2082                 return 0;
2083
2084         return 1;
2085 }
2086
2087 /* Called at mount-time, super-block is locked */
2088 static int ext4_check_descriptors(struct super_block *sb,
2089                                   ext4_group_t *first_not_zeroed)
2090 {
2091         struct ext4_sb_info *sbi = EXT4_SB(sb);
2092         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2093         ext4_fsblk_t last_block;
2094         ext4_fsblk_t block_bitmap;
2095         ext4_fsblk_t inode_bitmap;
2096         ext4_fsblk_t inode_table;
2097         int flexbg_flag = 0;
2098         ext4_group_t i, grp = sbi->s_groups_count;
2099
2100         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2101                 flexbg_flag = 1;
2102
2103         ext4_debug("Checking group descriptors");
2104
2105         for (i = 0; i < sbi->s_groups_count; i++) {
2106                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2107
2108                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2109                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2110                 else
2111                         last_block = first_block +
2112                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2113
2114                 if ((grp == sbi->s_groups_count) &&
2115                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2116                         grp = i;
2117
2118                 block_bitmap = ext4_block_bitmap(sb, gdp);
2119                 if (block_bitmap < first_block || block_bitmap > last_block) {
2120                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2121                                "Block bitmap for group %u not in group "
2122                                "(block %llu)!", i, block_bitmap);
2123                         return 0;
2124                 }
2125                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2126                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2127                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2128                                "Inode bitmap for group %u not in group "
2129                                "(block %llu)!", i, inode_bitmap);
2130                         return 0;
2131                 }
2132                 inode_table = ext4_inode_table(sb, gdp);
2133                 if (inode_table < first_block ||
2134                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2135                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2136                                "Inode table for group %u not in group "
2137                                "(block %llu)!", i, inode_table);
2138                         return 0;
2139                 }
2140                 ext4_lock_group(sb, i);
2141                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2142                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2143                                  "Checksum for group %u failed (%u!=%u)",
2144                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2145                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2146                         if (!(sb->s_flags & MS_RDONLY)) {
2147                                 ext4_unlock_group(sb, i);
2148                                 return 0;
2149                         }
2150                 }
2151                 ext4_unlock_group(sb, i);
2152                 if (!flexbg_flag)
2153                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2154         }
2155         if (NULL != first_not_zeroed)
2156                 *first_not_zeroed = grp;
2157
2158         ext4_free_blocks_count_set(sbi->s_es,
2159                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2160         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2161         return 1;
2162 }
2163
2164 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2165  * the superblock) which were deleted from all directories, but held open by
2166  * a process at the time of a crash.  We walk the list and try to delete these
2167  * inodes at recovery time (only with a read-write filesystem).
2168  *
2169  * In order to keep the orphan inode chain consistent during traversal (in
2170  * case of crash during recovery), we link each inode into the superblock
2171  * orphan list_head and handle it the same way as an inode deletion during
2172  * normal operation (which journals the operations for us).
2173  *
2174  * We only do an iget() and an iput() on each inode, which is very safe if we
2175  * accidentally point at an in-use or already deleted inode.  The worst that
2176  * can happen in this case is that we get a "bit already cleared" message from
2177  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2178  * e2fsck was run on this filesystem, and it must have already done the orphan
2179  * inode cleanup for us, so we can safely abort without any further action.
2180  */
2181 static void ext4_orphan_cleanup(struct super_block *sb,
2182                                 struct ext4_super_block *es)
2183 {
2184         unsigned int s_flags = sb->s_flags;
2185         int nr_orphans = 0, nr_truncates = 0;
2186 #ifdef CONFIG_QUOTA
2187         int i;
2188 #endif
2189         if (!es->s_last_orphan) {
2190                 jbd_debug(4, "no orphan inodes to clean up\n");
2191                 return;
2192         }
2193
2194         if (bdev_read_only(sb->s_bdev)) {
2195                 ext4_msg(sb, KERN_ERR, "write access "
2196                         "unavailable, skipping orphan cleanup");
2197                 return;
2198         }
2199
2200         /* Check if feature set would not allow a r/w mount */
2201         if (!ext4_feature_set_ok(sb, 0)) {
2202                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2203                          "unknown ROCOMPAT features");
2204                 return;
2205         }
2206
2207         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2208                 if (es->s_last_orphan)
2209                         jbd_debug(1, "Errors on filesystem, "
2210                                   "clearing orphan list.\n");
2211                 es->s_last_orphan = 0;
2212                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2213                 return;
2214         }
2215
2216         if (s_flags & MS_RDONLY) {
2217                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2218                 sb->s_flags &= ~MS_RDONLY;
2219         }
2220 #ifdef CONFIG_QUOTA
2221         /* Needed for iput() to work correctly and not trash data */
2222         sb->s_flags |= MS_ACTIVE;
2223         /* Turn on quotas so that they are updated correctly */
2224         for (i = 0; i < MAXQUOTAS; i++) {
2225                 if (EXT4_SB(sb)->s_qf_names[i]) {
2226                         int ret = ext4_quota_on_mount(sb, i);
2227                         if (ret < 0)
2228                                 ext4_msg(sb, KERN_ERR,
2229                                         "Cannot turn on journaled "
2230                                         "quota: error %d", ret);
2231                 }
2232         }
2233 #endif
2234
2235         while (es->s_last_orphan) {
2236                 struct inode *inode;
2237
2238                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2239                 if (IS_ERR(inode)) {
2240                         es->s_last_orphan = 0;
2241                         break;
2242                 }
2243
2244                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2245                 dquot_initialize(inode);
2246                 if (inode->i_nlink) {
2247                         ext4_msg(sb, KERN_DEBUG,
2248                                 "%s: truncating inode %lu to %lld bytes",
2249                                 __func__, inode->i_ino, inode->i_size);
2250                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2251                                   inode->i_ino, inode->i_size);
2252                         ext4_truncate(inode);
2253                         nr_truncates++;
2254                 } else {
2255                         ext4_msg(sb, KERN_DEBUG,
2256                                 "%s: deleting unreferenced inode %lu",
2257                                 __func__, inode->i_ino);
2258                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2259                                   inode->i_ino);
2260                         nr_orphans++;
2261                 }
2262                 iput(inode);  /* The delete magic happens here! */
2263         }
2264
2265 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2266
2267         if (nr_orphans)
2268                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2269                        PLURAL(nr_orphans));
2270         if (nr_truncates)
2271                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2272                        PLURAL(nr_truncates));
2273 #ifdef CONFIG_QUOTA
2274         /* Turn quotas off */
2275         for (i = 0; i < MAXQUOTAS; i++) {
2276                 if (sb_dqopt(sb)->files[i])
2277                         dquot_quota_off(sb, i);
2278         }
2279 #endif
2280         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2281 }
2282
2283 /*
2284  * Maximal extent format file size.
2285  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2286  * extent format containers, within a sector_t, and within i_blocks
2287  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2288  * so that won't be a limiting factor.
2289  *
2290  * However there is other limiting factor. We do store extents in the form
2291  * of starting block and length, hence the resulting length of the extent
2292  * covering maximum file size must fit into on-disk format containers as
2293  * well. Given that length is always by 1 unit bigger than max unit (because
2294  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2295  *
2296  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2297  */
2298 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2299 {
2300         loff_t res;
2301         loff_t upper_limit = MAX_LFS_FILESIZE;
2302
2303         /* small i_blocks in vfs inode? */
2304         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2305                 /*
2306                  * CONFIG_LBDAF is not enabled implies the inode
2307                  * i_block represent total blocks in 512 bytes
2308                  * 32 == size of vfs inode i_blocks * 8
2309                  */
2310                 upper_limit = (1LL << 32) - 1;
2311
2312                 /* total blocks in file system block size */
2313                 upper_limit >>= (blkbits - 9);
2314                 upper_limit <<= blkbits;
2315         }
2316
2317         /*
2318          * 32-bit extent-start container, ee_block. We lower the maxbytes
2319          * by one fs block, so ee_len can cover the extent of maximum file
2320          * size
2321          */
2322         res = (1LL << 32) - 1;
2323         res <<= blkbits;
2324
2325         /* Sanity check against vm- & vfs- imposed limits */
2326         if (res > upper_limit)
2327                 res = upper_limit;
2328
2329         return res;
2330 }
2331
2332 /*
2333  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2334  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2335  * We need to be 1 filesystem block less than the 2^48 sector limit.
2336  */
2337 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2338 {
2339         loff_t res = EXT4_NDIR_BLOCKS;
2340         int meta_blocks;
2341         loff_t upper_limit;
2342         /* This is calculated to be the largest file size for a dense, block
2343          * mapped file such that the file's total number of 512-byte sectors,
2344          * including data and all indirect blocks, does not exceed (2^48 - 1).
2345          *
2346          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2347          * number of 512-byte sectors of the file.
2348          */
2349
2350         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2351                 /*
2352                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2353                  * the inode i_block field represents total file blocks in
2354                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2355                  */
2356                 upper_limit = (1LL << 32) - 1;
2357
2358                 /* total blocks in file system block size */
2359                 upper_limit >>= (bits - 9);
2360
2361         } else {
2362                 /*
2363                  * We use 48 bit ext4_inode i_blocks
2364                  * With EXT4_HUGE_FILE_FL set the i_blocks
2365                  * represent total number of blocks in
2366                  * file system block size
2367                  */
2368                 upper_limit = (1LL << 48) - 1;
2369
2370         }
2371
2372         /* indirect blocks */
2373         meta_blocks = 1;
2374         /* double indirect blocks */
2375         meta_blocks += 1 + (1LL << (bits-2));
2376         /* tripple indirect blocks */
2377         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2378
2379         upper_limit -= meta_blocks;
2380         upper_limit <<= bits;
2381
2382         res += 1LL << (bits-2);
2383         res += 1LL << (2*(bits-2));
2384         res += 1LL << (3*(bits-2));
2385         res <<= bits;
2386         if (res > upper_limit)
2387                 res = upper_limit;
2388
2389         if (res > MAX_LFS_FILESIZE)
2390                 res = MAX_LFS_FILESIZE;
2391
2392         return res;
2393 }
2394
2395 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2396                                    ext4_fsblk_t logical_sb_block, int nr)
2397 {
2398         struct ext4_sb_info *sbi = EXT4_SB(sb);
2399         ext4_group_t bg, first_meta_bg;
2400         int has_super = 0;
2401
2402         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2403
2404         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2405             nr < first_meta_bg)
2406                 return logical_sb_block + nr + 1;
2407         bg = sbi->s_desc_per_block * nr;
2408         if (ext4_bg_has_super(sb, bg))
2409                 has_super = 1;
2410
2411         return (has_super + ext4_group_first_block_no(sb, bg));
2412 }
2413
2414 /**
2415  * ext4_get_stripe_size: Get the stripe size.
2416  * @sbi: In memory super block info
2417  *
2418  * If we have specified it via mount option, then
2419  * use the mount option value. If the value specified at mount time is
2420  * greater than the blocks per group use the super block value.
2421  * If the super block value is greater than blocks per group return 0.
2422  * Allocator needs it be less than blocks per group.
2423  *
2424  */
2425 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2426 {
2427         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2428         unsigned long stripe_width =
2429                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2430         int ret;
2431
2432         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2433                 ret = sbi->s_stripe;
2434         else if (stripe_width <= sbi->s_blocks_per_group)
2435                 ret = stripe_width;
2436         else if (stride <= sbi->s_blocks_per_group)
2437                 ret = stride;
2438         else
2439                 ret = 0;
2440
2441         /*
2442          * If the stripe width is 1, this makes no sense and
2443          * we set it to 0 to turn off stripe handling code.
2444          */
2445         if (ret <= 1)
2446                 ret = 0;
2447
2448         return ret;
2449 }
2450
2451 /* sysfs supprt */
2452
2453 struct ext4_attr {
2454         struct attribute attr;
2455         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2456         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2457                          const char *, size_t);
2458         int offset;
2459 };
2460
2461 static int parse_strtoul(const char *buf,
2462                 unsigned long max, unsigned long *value)
2463 {
2464         char *endp;
2465
2466         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2467         endp = skip_spaces(endp);
2468         if (*endp || *value > max)
2469                 return -EINVAL;
2470
2471         return 0;
2472 }
2473
2474 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2475                                               struct ext4_sb_info *sbi,
2476                                               char *buf)
2477 {
2478         return snprintf(buf, PAGE_SIZE, "%llu\n",
2479                 (s64) EXT4_C2B(sbi,
2480                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2481 }
2482
2483 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2484                                          struct ext4_sb_info *sbi, char *buf)
2485 {
2486         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2487
2488         if (!sb->s_bdev->bd_part)
2489                 return snprintf(buf, PAGE_SIZE, "0\n");
2490         return snprintf(buf, PAGE_SIZE, "%lu\n",
2491                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2492                          sbi->s_sectors_written_start) >> 1);
2493 }
2494
2495 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2496                                           struct ext4_sb_info *sbi, char *buf)
2497 {
2498         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2499
2500         if (!sb->s_bdev->bd_part)
2501                 return snprintf(buf, PAGE_SIZE, "0\n");
2502         return snprintf(buf, PAGE_SIZE, "%llu\n",
2503                         (unsigned long long)(sbi->s_kbytes_written +
2504                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2505                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2506 }
2507
2508 static ssize_t extent_cache_hits_show(struct ext4_attr *a,
2509                                       struct ext4_sb_info *sbi, char *buf)
2510 {
2511         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
2512 }
2513
2514 static ssize_t extent_cache_misses_show(struct ext4_attr *a,
2515                                         struct ext4_sb_info *sbi, char *buf)
2516 {
2517         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
2518 }
2519
2520 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2521                                           struct ext4_sb_info *sbi,
2522                                           const char *buf, size_t count)
2523 {
2524         unsigned long t;
2525
2526         if (parse_strtoul(buf, 0x40000000, &t))
2527                 return -EINVAL;
2528
2529         if (t && !is_power_of_2(t))
2530                 return -EINVAL;
2531
2532         sbi->s_inode_readahead_blks = t;
2533         return count;
2534 }
2535
2536 static ssize_t sbi_ui_show(struct ext4_attr *a,
2537                            struct ext4_sb_info *sbi, char *buf)
2538 {
2539         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2540
2541         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2542 }
2543
2544 static ssize_t sbi_ui_store(struct ext4_attr *a,
2545                             struct ext4_sb_info *sbi,
2546                             const char *buf, size_t count)
2547 {
2548         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2549         unsigned long t;
2550
2551         if (parse_strtoul(buf, 0xffffffff, &t))
2552                 return -EINVAL;
2553         *ui = t;
2554         return count;
2555 }
2556
2557 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2558 static struct ext4_attr ext4_attr_##_name = {                   \
2559         .attr = {.name = __stringify(_name), .mode = _mode },   \
2560         .show   = _show,                                        \
2561         .store  = _store,                                       \
2562         .offset = offsetof(struct ext4_sb_info, _elname),       \
2563 }
2564 #define EXT4_ATTR(name, mode, show, store) \
2565 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2566
2567 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2568 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2569 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2570 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2571         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2572 #define ATTR_LIST(name) &ext4_attr_##name.attr
2573
2574 EXT4_RO_ATTR(delayed_allocation_blocks);
2575 EXT4_RO_ATTR(session_write_kbytes);
2576 EXT4_RO_ATTR(lifetime_write_kbytes);
2577 EXT4_RO_ATTR(extent_cache_hits);
2578 EXT4_RO_ATTR(extent_cache_misses);
2579 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2580                  inode_readahead_blks_store, s_inode_readahead_blks);
2581 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2582 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2583 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2584 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2585 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2586 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2587 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2588 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2589
2590 static struct attribute *ext4_attrs[] = {
2591         ATTR_LIST(delayed_allocation_blocks),
2592         ATTR_LIST(session_write_kbytes),
2593         ATTR_LIST(lifetime_write_kbytes),
2594         ATTR_LIST(extent_cache_hits),
2595         ATTR_LIST(extent_cache_misses),
2596         ATTR_LIST(inode_readahead_blks),
2597         ATTR_LIST(inode_goal),
2598         ATTR_LIST(mb_stats),
2599         ATTR_LIST(mb_max_to_scan),
2600         ATTR_LIST(mb_min_to_scan),
2601         ATTR_LIST(mb_order2_req),
2602         ATTR_LIST(mb_stream_req),
2603         ATTR_LIST(mb_group_prealloc),
2604         ATTR_LIST(max_writeback_mb_bump),
2605         NULL,
2606 };
2607
2608 /* Features this copy of ext4 supports */
2609 EXT4_INFO_ATTR(lazy_itable_init);
2610 EXT4_INFO_ATTR(batched_discard);
2611
2612 static struct attribute *ext4_feat_attrs[] = {
2613         ATTR_LIST(lazy_itable_init),
2614         ATTR_LIST(batched_discard),
2615         NULL,
2616 };
2617
2618 static ssize_t ext4_attr_show(struct kobject *kobj,
2619                               struct attribute *attr, char *buf)
2620 {
2621         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2622                                                 s_kobj);
2623         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2624
2625         return a->show ? a->show(a, sbi, buf) : 0;
2626 }
2627
2628 static ssize_t ext4_attr_store(struct kobject *kobj,
2629                                struct attribute *attr,
2630                                const char *buf, size_t len)
2631 {
2632         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2633                                                 s_kobj);
2634         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2635
2636         return a->store ? a->store(a, sbi, buf, len) : 0;
2637 }
2638
2639 static void ext4_sb_release(struct kobject *kobj)
2640 {
2641         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2642                                                 s_kobj);
2643         complete(&sbi->s_kobj_unregister);
2644 }
2645
2646 static const struct sysfs_ops ext4_attr_ops = {
2647         .show   = ext4_attr_show,
2648         .store  = ext4_attr_store,
2649 };
2650
2651 static struct kobj_type ext4_ktype = {
2652         .default_attrs  = ext4_attrs,
2653         .sysfs_ops      = &ext4_attr_ops,
2654         .release        = ext4_sb_release,
2655 };
2656
2657 static void ext4_feat_release(struct kobject *kobj)
2658 {
2659         complete(&ext4_feat->f_kobj_unregister);
2660 }
2661
2662 static struct kobj_type ext4_feat_ktype = {
2663         .default_attrs  = ext4_feat_attrs,
2664         .sysfs_ops      = &ext4_attr_ops,
2665         .release        = ext4_feat_release,
2666 };
2667
2668 /*
2669  * Check whether this filesystem can be mounted based on
2670  * the features present and the RDONLY/RDWR mount requested.
2671  * Returns 1 if this filesystem can be mounted as requested,
2672  * 0 if it cannot be.
2673  */
2674 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2675 {
2676         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2677                 ext4_msg(sb, KERN_ERR,
2678                         "Couldn't mount because of "
2679                         "unsupported optional features (%x)",
2680                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2681                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2682                 return 0;
2683         }
2684
2685         if (readonly)
2686                 return 1;
2687
2688         /* Check that feature set is OK for a read-write mount */
2689         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2690                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2691                          "unsupported optional features (%x)",
2692                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2693                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2694                 return 0;
2695         }
2696         /*
2697          * Large file size enabled file system can only be mounted
2698          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2699          */
2700         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2701                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2702                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2703                                  "cannot be mounted RDWR without "
2704                                  "CONFIG_LBDAF");
2705                         return 0;
2706                 }
2707         }
2708         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2709             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2710                 ext4_msg(sb, KERN_ERR,
2711                          "Can't support bigalloc feature without "
2712                          "extents feature\n");
2713                 return 0;
2714         }
2715         return 1;
2716 }
2717
2718 /*
2719  * This function is called once a day if we have errors logged
2720  * on the file system
2721  */
2722 static void print_daily_error_info(unsigned long arg)
2723 {
2724         struct super_block *sb = (struct super_block *) arg;
2725         struct ext4_sb_info *sbi;
2726         struct ext4_super_block *es;
2727
2728         sbi = EXT4_SB(sb);
2729         es = sbi->s_es;
2730
2731         if (es->s_error_count)
2732                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2733                          le32_to_cpu(es->s_error_count));
2734         if (es->s_first_error_time) {
2735                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2736                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2737                        (int) sizeof(es->s_first_error_func),
2738                        es->s_first_error_func,
2739                        le32_to_cpu(es->s_first_error_line));
2740                 if (es->s_first_error_ino)
2741                         printk(": inode %u",
2742                                le32_to_cpu(es->s_first_error_ino));
2743                 if (es->s_first_error_block)
2744                         printk(": block %llu", (unsigned long long)
2745                                le64_to_cpu(es->s_first_error_block));
2746                 printk("\n");
2747         }
2748         if (es->s_last_error_time) {
2749                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2750                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2751                        (int) sizeof(es->s_last_error_func),
2752                        es->s_last_error_func,
2753                        le32_to_cpu(es->s_last_error_line));
2754                 if (es->s_last_error_ino)
2755                         printk(": inode %u",
2756                                le32_to_cpu(es->s_last_error_ino));
2757                 if (es->s_last_error_block)
2758                         printk(": block %llu", (unsigned long long)
2759                                le64_to_cpu(es->s_last_error_block));
2760                 printk("\n");
2761         }
2762         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2763 }
2764
2765 /* Find next suitable group and run ext4_init_inode_table */
2766 static int ext4_run_li_request(struct ext4_li_request *elr)
2767 {
2768         struct ext4_group_desc *gdp = NULL;
2769         ext4_group_t group, ngroups;
2770         struct super_block *sb;
2771         unsigned long timeout = 0;
2772         int ret = 0;
2773
2774         sb = elr->lr_super;
2775         ngroups = EXT4_SB(sb)->s_groups_count;
2776
2777         for (group = elr->lr_next_group; group < ngroups; group++) {
2778                 gdp = ext4_get_group_desc(sb, group, NULL);
2779                 if (!gdp) {
2780                         ret = 1;
2781                         break;
2782                 }
2783
2784                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2785                         break;
2786         }
2787
2788         if (group == ngroups)
2789                 ret = 1;
2790
2791         if (!ret) {
2792                 timeout = jiffies;
2793                 ret = ext4_init_inode_table(sb, group,
2794                                             elr->lr_timeout ? 0 : 1);
2795                 if (elr->lr_timeout == 0) {
2796                         timeout = (jiffies - timeout) *
2797                                   elr->lr_sbi->s_li_wait_mult;
2798                         elr->lr_timeout = timeout;
2799                 }
2800                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2801                 elr->lr_next_group = group + 1;
2802         }
2803
2804         return ret;
2805 }
2806
2807 /*
2808  * Remove lr_request from the list_request and free the
2809  * request structure. Should be called with li_list_mtx held
2810  */
2811 static void ext4_remove_li_request(struct ext4_li_request *elr)
2812 {
2813         struct ext4_sb_info *sbi;
2814
2815         if (!elr)
2816                 return;
2817
2818         sbi = elr->lr_sbi;
2819
2820         list_del(&elr->lr_request);
2821         sbi->s_li_request = NULL;
2822         kfree(elr);
2823 }
2824
2825 static void ext4_unregister_li_request(struct super_block *sb)
2826 {
2827         mutex_lock(&ext4_li_mtx);
2828         if (!ext4_li_info) {
2829                 mutex_unlock(&ext4_li_mtx);
2830                 return;
2831         }
2832
2833         mutex_lock(&ext4_li_info->li_list_mtx);
2834         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2835         mutex_unlock(&ext4_li_info->li_list_mtx);
2836         mutex_unlock(&ext4_li_mtx);
2837 }
2838
2839 static struct task_struct *ext4_lazyinit_task;
2840
2841 /*
2842  * This is the function where ext4lazyinit thread lives. It walks
2843  * through the request list searching for next scheduled filesystem.
2844  * When such a fs is found, run the lazy initialization request
2845  * (ext4_rn_li_request) and keep track of the time spend in this
2846  * function. Based on that time we compute next schedule time of
2847  * the request. When walking through the list is complete, compute
2848  * next waking time and put itself into sleep.
2849  */
2850 static int ext4_lazyinit_thread(void *arg)
2851 {
2852         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2853         struct list_head *pos, *n;
2854         struct ext4_li_request *elr;
2855         unsigned long next_wakeup, cur;
2856
2857         BUG_ON(NULL == eli);
2858
2859 cont_thread:
2860         while (true) {
2861                 next_wakeup = MAX_JIFFY_OFFSET;
2862
2863                 mutex_lock(&eli->li_list_mtx);
2864                 if (list_empty(&eli->li_request_list)) {
2865                         mutex_unlock(&eli->li_list_mtx);
2866                         goto exit_thread;
2867                 }
2868
2869                 list_for_each_safe(pos, n, &eli->li_request_list) {
2870                         elr = list_entry(pos, struct ext4_li_request,
2871                                          lr_request);
2872
2873                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2874                                 if (ext4_run_li_request(elr) != 0) {
2875                                         /* error, remove the lazy_init job */
2876                                         ext4_remove_li_request(elr);
2877                                         continue;
2878                                 }
2879                         }
2880
2881                         if (time_before(elr->lr_next_sched, next_wakeup))
2882                                 next_wakeup = elr->lr_next_sched;
2883                 }
2884                 mutex_unlock(&eli->li_list_mtx);
2885
2886                 if (freezing(current))
2887                         refrigerator();
2888
2889                 cur = jiffies;
2890                 if ((time_after_eq(cur, next_wakeup)) ||
2891                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2892                         cond_resched();
2893                         continue;
2894                 }
2895
2896                 schedule_timeout_interruptible(next_wakeup - cur);
2897
2898                 if (kthread_should_stop()) {
2899                         ext4_clear_request_list();
2900                         goto exit_thread;
2901                 }
2902         }
2903
2904 exit_thread:
2905         /*
2906          * It looks like the request list is empty, but we need
2907          * to check it under the li_list_mtx lock, to prevent any
2908          * additions into it, and of course we should lock ext4_li_mtx
2909          * to atomically free the list and ext4_li_info, because at
2910          * this point another ext4 filesystem could be registering
2911          * new one.
2912          */
2913         mutex_lock(&ext4_li_mtx);
2914         mutex_lock(&eli->li_list_mtx);
2915         if (!list_empty(&eli->li_request_list)) {
2916                 mutex_unlock(&eli->li_list_mtx);
2917                 mutex_unlock(&ext4_li_mtx);
2918                 goto cont_thread;
2919         }
2920         mutex_unlock(&eli->li_list_mtx);
2921         kfree(ext4_li_info);
2922         ext4_li_info = NULL;
2923         mutex_unlock(&ext4_li_mtx);
2924
2925         return 0;
2926 }
2927
2928 static void ext4_clear_request_list(void)
2929 {
2930         struct list_head *pos, *n;
2931         struct ext4_li_request *elr;
2932
2933         mutex_lock(&ext4_li_info->li_list_mtx);
2934         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2935                 elr = list_entry(pos, struct ext4_li_request,
2936                                  lr_request);
2937                 ext4_remove_li_request(elr);
2938         }
2939         mutex_unlock(&ext4_li_info->li_list_mtx);
2940 }
2941
2942 static int ext4_run_lazyinit_thread(void)
2943 {
2944         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2945                                          ext4_li_info, "ext4lazyinit");
2946         if (IS_ERR(ext4_lazyinit_task)) {
2947                 int err = PTR_ERR(ext4_lazyinit_task);
2948                 ext4_clear_request_list();
2949                 kfree(ext4_li_info);
2950                 ext4_li_info = NULL;
2951                 printk(KERN_CRIT "EXT4: error %d creating inode table "
2952                                  "initialization thread\n",
2953                                  err);
2954                 return err;
2955         }
2956         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2957         return 0;
2958 }
2959
2960 /*
2961  * Check whether it make sense to run itable init. thread or not.
2962  * If there is at least one uninitialized inode table, return
2963  * corresponding group number, else the loop goes through all
2964  * groups and return total number of groups.
2965  */
2966 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2967 {
2968         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2969         struct ext4_group_desc *gdp = NULL;
2970
2971         for (group = 0; group < ngroups; group++) {
2972                 gdp = ext4_get_group_desc(sb, group, NULL);
2973                 if (!gdp)
2974                         continue;
2975
2976                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2977                         break;
2978         }
2979
2980         return group;
2981 }
2982
2983 static int ext4_li_info_new(void)
2984 {
2985         struct ext4_lazy_init *eli = NULL;
2986
2987         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2988         if (!eli)
2989                 return -ENOMEM;
2990
2991         INIT_LIST_HEAD(&eli->li_request_list);
2992         mutex_init(&eli->li_list_mtx);
2993
2994         eli->li_state |= EXT4_LAZYINIT_QUIT;
2995
2996         ext4_li_info = eli;
2997
2998         return 0;
2999 }
3000
3001 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3002                                             ext4_group_t start)
3003 {
3004         struct ext4_sb_info *sbi = EXT4_SB(sb);
3005         struct ext4_li_request *elr;
3006         unsigned long rnd;
3007
3008         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3009         if (!elr)
3010                 return NULL;
3011
3012         elr->lr_super = sb;
3013         elr->lr_sbi = sbi;
3014         elr->lr_next_group = start;
3015
3016         /*
3017          * Randomize first schedule time of the request to
3018          * spread the inode table initialization requests
3019          * better.
3020          */
3021         get_random_bytes(&rnd, sizeof(rnd));
3022         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3023                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3024
3025         return elr;
3026 }
3027
3028 static int ext4_register_li_request(struct super_block *sb,
3029                                     ext4_group_t first_not_zeroed)
3030 {
3031         struct ext4_sb_info *sbi = EXT4_SB(sb);
3032         struct ext4_li_request *elr;
3033         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3034         int ret = 0;
3035
3036         if (sbi->s_li_request != NULL) {
3037                 /*
3038                  * Reset timeout so it can be computed again, because
3039                  * s_li_wait_mult might have changed.
3040                  */
3041                 sbi->s_li_request->lr_timeout = 0;
3042                 return 0;
3043         }
3044
3045         if (first_not_zeroed == ngroups ||
3046             (sb->s_flags & MS_RDONLY) ||
3047             !test_opt(sb, INIT_INODE_TABLE))
3048                 return 0;
3049
3050         elr = ext4_li_request_new(sb, first_not_zeroed);
3051         if (!elr)
3052                 return -ENOMEM;
3053
3054         mutex_lock(&ext4_li_mtx);
3055
3056         if (NULL == ext4_li_info) {
3057                 ret = ext4_li_info_new();
3058                 if (ret)
3059                         goto out;
3060         }
3061
3062         mutex_lock(&ext4_li_info->li_list_mtx);
3063         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3064         mutex_unlock(&ext4_li_info->li_list_mtx);
3065
3066         sbi->s_li_request = elr;
3067         /*
3068          * set elr to NULL here since it has been inserted to
3069          * the request_list and the removal and free of it is
3070          * handled by ext4_clear_request_list from now on.
3071          */
3072         elr = NULL;
3073
3074         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3075                 ret = ext4_run_lazyinit_thread();
3076                 if (ret)
3077                         goto out;
3078         }
3079 out:
3080         mutex_unlock(&ext4_li_mtx);
3081         if (ret)
3082                 kfree(elr);
3083         return ret;
3084 }
3085
3086 /*
3087  * We do not need to lock anything since this is called on
3088  * module unload.
3089  */
3090 static void ext4_destroy_lazyinit_thread(void)
3091 {
3092         /*
3093          * If thread exited earlier
3094          * there's nothing to be done.
3095          */
3096         if (!ext4_li_info || !ext4_lazyinit_task)
3097                 return;
3098
3099         kthread_stop(ext4_lazyinit_task);
3100 }
3101
3102 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3103 {
3104         char *orig_data = kstrdup(data, GFP_KERNEL);
3105         struct buffer_head *bh;
3106         struct ext4_super_block *es = NULL;
3107         struct ext4_sb_info *sbi;
3108         ext4_fsblk_t block;
3109         ext4_fsblk_t sb_block = get_sb_block(&data);
3110         ext4_fsblk_t logical_sb_block;
3111         unsigned long offset = 0;
3112         unsigned long journal_devnum = 0;
3113         unsigned long def_mount_opts;
3114         struct inode *root;
3115         char *cp;
3116         const char *descr;
3117         int ret = -ENOMEM;
3118         int blocksize, clustersize;
3119         unsigned int db_count;
3120         unsigned int i;
3121         int needs_recovery, has_huge_files, has_bigalloc;
3122         __u64 blocks_count;
3123         int err;
3124         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3125         ext4_group_t first_not_zeroed;
3126
3127         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3128         if (!sbi)
3129                 goto out_free_orig;
3130
3131         sbi->s_blockgroup_lock =
3132                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3133         if (!sbi->s_blockgroup_lock) {
3134                 kfree(sbi);
3135                 goto out_free_orig;
3136         }
3137         sb->s_fs_info = sbi;
3138         sbi->s_mount_opt = 0;
3139         sbi->s_resuid = EXT4_DEF_RESUID;
3140         sbi->s_resgid = EXT4_DEF_RESGID;
3141         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3142         sbi->s_sb_block = sb_block;
3143         if (sb->s_bdev->bd_part)
3144                 sbi->s_sectors_written_start =
3145                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3146
3147         /* Cleanup superblock name */
3148         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3149                 *cp = '!';
3150
3151         ret = -EINVAL;
3152         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3153         if (!blocksize) {
3154                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3155                 goto out_fail;
3156         }
3157
3158         /*
3159          * The ext4 superblock will not be buffer aligned for other than 1kB
3160          * block sizes.  We need to calculate the offset from buffer start.
3161          */
3162         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3163                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3164                 offset = do_div(logical_sb_block, blocksize);
3165         } else {
3166                 logical_sb_block = sb_block;
3167         }
3168
3169         if (!(bh = sb_bread(sb, logical_sb_block))) {
3170                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3171                 goto out_fail;
3172         }
3173         /*
3174          * Note: s_es must be initialized as soon as possible because
3175          *       some ext4 macro-instructions depend on its value
3176          */
3177         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3178         sbi->s_es = es;
3179         sb->s_magic = le16_to_cpu(es->s_magic);
3180         if (sb->s_magic != EXT4_SUPER_MAGIC)
3181                 goto cantfind_ext4;
3182         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3183
3184         /* Set defaults before we parse the mount options */
3185         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3186         set_opt(sb, INIT_INODE_TABLE);
3187         if (def_mount_opts & EXT4_DEFM_DEBUG)
3188                 set_opt(sb, DEBUG);
3189         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3190                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3191                         "2.6.38");
3192                 set_opt(sb, GRPID);
3193         }
3194         if (def_mount_opts & EXT4_DEFM_UID16)
3195                 set_opt(sb, NO_UID32);
3196         /* xattr user namespace & acls are now defaulted on */
3197 #ifdef CONFIG_EXT4_FS_XATTR
3198         set_opt(sb, XATTR_USER);
3199 #endif
3200 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3201         set_opt(sb, POSIX_ACL);
3202 #endif
3203         set_opt(sb, MBLK_IO_SUBMIT);
3204         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3205                 set_opt(sb, JOURNAL_DATA);
3206         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3207                 set_opt(sb, ORDERED_DATA);
3208         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3209                 set_opt(sb, WRITEBACK_DATA);
3210
3211         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3212                 set_opt(sb, ERRORS_PANIC);
3213         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3214                 set_opt(sb, ERRORS_CONT);
3215         else
3216                 set_opt(sb, ERRORS_RO);
3217         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3218                 set_opt(sb, BLOCK_VALIDITY);
3219         if (def_mount_opts & EXT4_DEFM_DISCARD)
3220                 set_opt(sb, DISCARD);
3221
3222         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3223         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3224         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3225         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3226         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3227
3228         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3229                 set_opt(sb, BARRIER);
3230
3231         /*
3232          * enable delayed allocation by default
3233          * Use -o nodelalloc to turn it off
3234          */
3235         if (!IS_EXT3_SB(sb) &&
3236             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3237                 set_opt(sb, DELALLOC);
3238
3239         /*
3240          * set default s_li_wait_mult for lazyinit, for the case there is
3241          * no mount option specified.
3242          */
3243         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3244
3245         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3246                            &journal_devnum, &journal_ioprio, NULL, 0)) {
3247                 ext4_msg(sb, KERN_WARNING,
3248                          "failed to parse options in superblock: %s",
3249                          sbi->s_es->s_mount_opts);
3250         }
3251         if (!parse_options((char *) data, sb, &journal_devnum,
3252                            &journal_ioprio, NULL, 0))
3253                 goto failed_mount;
3254
3255         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3256                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3257                             "with data=journal disables delayed "
3258                             "allocation and O_DIRECT support!\n");
3259                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3260                         ext4_msg(sb, KERN_ERR, "can't mount with "
3261                                  "both data=journal and delalloc");
3262                         goto failed_mount;
3263                 }
3264                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3265                         ext4_msg(sb, KERN_ERR, "can't mount with "
3266                                  "both data=journal and delalloc");
3267                         goto failed_mount;
3268                 }
3269                 if (test_opt(sb, DELALLOC))
3270                         clear_opt(sb, DELALLOC);
3271         }
3272
3273         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3274         if (test_opt(sb, DIOREAD_NOLOCK)) {
3275                 if (blocksize < PAGE_SIZE) {
3276                         ext4_msg(sb, KERN_ERR, "can't mount with "
3277                                  "dioread_nolock if block size != PAGE_SIZE");
3278                         goto failed_mount;
3279                 }
3280         }
3281
3282         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3283                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3284
3285         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3286             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3287              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3288              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3289                 ext4_msg(sb, KERN_WARNING,
3290                        "feature flags set on rev 0 fs, "
3291                        "running e2fsck is recommended");
3292
3293         if (IS_EXT2_SB(sb)) {
3294                 if (ext2_feature_set_ok(sb))
3295                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3296                                  "using the ext4 subsystem");
3297                 else {
3298                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3299                                  "to feature incompatibilities");
3300                         goto failed_mount;
3301                 }
3302         }
3303
3304         if (IS_EXT3_SB(sb)) {
3305                 if (ext3_feature_set_ok(sb))
3306                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3307                                  "using the ext4 subsystem");
3308                 else {
3309                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3310                                  "to feature incompatibilities");
3311                         goto failed_mount;
3312                 }
3313         }
3314
3315         /*
3316          * Check feature flags regardless of the revision level, since we
3317          * previously didn't change the revision level when setting the flags,
3318          * so there is a chance incompat flags are set on a rev 0 filesystem.
3319          */
3320         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3321                 goto failed_mount;
3322
3323         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3324             blocksize > EXT4_MAX_BLOCK_SIZE) {
3325                 ext4_msg(sb, KERN_ERR,
3326                        "Unsupported filesystem blocksize %d", blocksize);
3327                 goto failed_mount;
3328         }
3329
3330         if (sb->s_blocksize != blocksize) {
3331                 /* Validate the filesystem blocksize */
3332                 if (!sb_set_blocksize(sb, blocksize)) {
3333                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3334                                         blocksize);
3335                         goto failed_mount;
3336                 }
3337
3338                 brelse(bh);
3339                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3340                 offset = do_div(logical_sb_block, blocksize);
3341                 bh = sb_bread(sb, logical_sb_block);
3342                 if (!bh) {
3343                         ext4_msg(sb, KERN_ERR,
3344                                "Can't read superblock on 2nd try");
3345                         goto failed_mount;
3346                 }
3347                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3348                 sbi->s_es = es;
3349                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3350                         ext4_msg(sb, KERN_ERR,
3351                                "Magic mismatch, very weird!");
3352                         goto failed_mount;
3353                 }
3354         }
3355
3356         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3357                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3358         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3359                                                       has_huge_files);
3360         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3361
3362         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3363                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3364                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3365         } else {
3366                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3367                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3368                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3369                     (!is_power_of_2(sbi->s_inode_size)) ||
3370                     (sbi->s_inode_size > blocksize)) {
3371                         ext4_msg(sb, KERN_ERR,
3372                                "unsupported inode size: %d",
3373                                sbi->s_inode_size);
3374                         goto failed_mount;
3375                 }
3376                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3377                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3378         }
3379
3380         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3381         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3382                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3383                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3384                     !is_power_of_2(sbi->s_desc_size)) {
3385                         ext4_msg(sb, KERN_ERR,
3386                                "unsupported descriptor size %lu",
3387                                sbi->s_desc_size);
3388                         goto failed_mount;
3389                 }
3390         } else
3391                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3392
3393         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3394         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3395         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3396                 goto cantfind_ext4;
3397
3398         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3399         if (sbi->s_inodes_per_block == 0)
3400                 goto cantfind_ext4;
3401         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3402                                         sbi->s_inodes_per_block;
3403         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3404         sbi->s_sbh = bh;
3405         sbi->s_mount_state = le16_to_cpu(es->s_state);
3406         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3407         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3408
3409         for (i = 0; i < 4; i++)
3410                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3411         sbi->s_def_hash_version = es->s_def_hash_version;
3412         i = le32_to_cpu(es->s_flags);
3413         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3414                 sbi->s_hash_unsigned = 3;
3415         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3416 #ifdef __CHAR_UNSIGNED__
3417                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3418                 sbi->s_hash_unsigned = 3;
3419 #else
3420                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3421 #endif
3422                 sb->s_dirt = 1;
3423         }
3424
3425         /* Handle clustersize */
3426         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3427         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3428                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3429         if (has_bigalloc) {
3430                 if (clustersize < blocksize) {
3431                         ext4_msg(sb, KERN_ERR,
3432                                  "cluster size (%d) smaller than "
3433                                  "block size (%d)", clustersize, blocksize);
3434                         goto failed_mount;
3435                 }
3436                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3437                         le32_to_cpu(es->s_log_block_size);
3438                 sbi->s_clusters_per_group =
3439                         le32_to_cpu(es->s_clusters_per_group);
3440                 if (sbi->s_clusters_per_group > blocksize * 8) {
3441                         ext4_msg(sb, KERN_ERR,
3442                                  "#clusters per group too big: %lu",
3443                                  sbi->s_clusters_per_group);
3444                         goto failed_mount;
3445                 }
3446                 if (sbi->s_blocks_per_group !=
3447                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3448                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3449                                  "clusters per group (%lu) inconsistent",
3450                                  sbi->s_blocks_per_group,
3451                                  sbi->s_clusters_per_group);
3452                         goto failed_mount;
3453                 }
3454         } else {
3455                 if (clustersize != blocksize) {
3456                         ext4_warning(sb, "fragment/cluster size (%d) != "
3457                                      "block size (%d)", clustersize,
3458                                      blocksize);
3459                         clustersize = blocksize;
3460                 }
3461                 if (sbi->s_blocks_per_group > blocksize * 8) {
3462                         ext4_msg(sb, KERN_ERR,
3463                                  "#blocks per group too big: %lu",
3464                                  sbi->s_blocks_per_group);
3465                         goto failed_mount;
3466                 }
3467                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3468                 sbi->s_cluster_bits = 0;
3469         }
3470         sbi->s_cluster_ratio = clustersize / blocksize;
3471
3472         if (sbi->s_inodes_per_group > blocksize * 8) {
3473                 ext4_msg(sb, KERN_ERR,
3474                        "#inodes per group too big: %lu",
3475                        sbi->s_inodes_per_group);
3476                 goto failed_mount;
3477         }
3478
3479         /*
3480          * Test whether we have more sectors than will fit in sector_t,
3481          * and whether the max offset is addressable by the page cache.
3482          */
3483         err = generic_check_addressable(sb->s_blocksize_bits,
3484                                         ext4_blocks_count(es));
3485         if (err) {
3486                 ext4_msg(sb, KERN_ERR, "filesystem"
3487                          " too large to mount safely on this system");
3488                 if (sizeof(sector_t) < 8)
3489                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3490                 ret = err;
3491                 goto failed_mount;
3492         }
3493
3494         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3495                 goto cantfind_ext4;
3496
3497         /* check blocks count against device size */
3498         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3499         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3500                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3501                        "exceeds size of device (%llu blocks)",
3502                        ext4_blocks_count(es), blocks_count);
3503                 goto failed_mount;
3504         }
3505
3506         /*
3507          * It makes no sense for the first data block to be beyond the end
3508          * of the filesystem.
3509          */
3510         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3511                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3512                          "block %u is beyond end of filesystem (%llu)",
3513                          le32_to_cpu(es->s_first_data_block),
3514                          ext4_blocks_count(es));
3515                 goto failed_mount;
3516         }
3517         blocks_count = (ext4_blocks_count(es) -
3518                         le32_to_cpu(es->s_first_data_block) +
3519                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3520         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3521         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3522                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3523                        "(block count %llu, first data block %u, "
3524                        "blocks per group %lu)", sbi->s_groups_count,
3525                        ext4_blocks_count(es),
3526                        le32_to_cpu(es->s_first_data_block),
3527                        EXT4_BLOCKS_PER_GROUP(sb));
3528                 goto failed_mount;
3529         }
3530         sbi->s_groups_count = blocks_count;
3531         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3532                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3533         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3534                    EXT4_DESC_PER_BLOCK(sb);
3535         sbi->s_group_desc = ext4_kvmalloc(db_count *
3536                                           sizeof(struct buffer_head *),
3537                                           GFP_KERNEL);
3538         if (sbi->s_group_desc == NULL) {
3539                 ext4_msg(sb, KERN_ERR, "not enough memory");
3540                 goto failed_mount;
3541         }
3542
3543         if (ext4_proc_root)
3544                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3545
3546         bgl_lock_init(sbi->s_blockgroup_lock);
3547
3548         for (i = 0; i < db_count; i++) {
3549                 block = descriptor_loc(sb, logical_sb_block, i);
3550                 sbi->s_group_desc[i] = sb_bread(sb, block);
3551                 if (!sbi->s_group_desc[i]) {
3552                         ext4_msg(sb, KERN_ERR,
3553                                "can't read group descriptor %d", i);
3554                         db_count = i;
3555                         goto failed_mount2;
3556                 }
3557         }
3558         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3559                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3560                 goto failed_mount2;
3561         }
3562         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3563                 if (!ext4_fill_flex_info(sb)) {
3564                         ext4_msg(sb, KERN_ERR,
3565                                "unable to initialize "
3566                                "flex_bg meta info!");
3567                         goto failed_mount2;
3568                 }
3569
3570         sbi->s_gdb_count = db_count;
3571         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3572         spin_lock_init(&sbi->s_next_gen_lock);
3573
3574         init_timer(&sbi->s_err_report);
3575         sbi->s_err_report.function = print_daily_error_info;
3576         sbi->s_err_report.data = (unsigned long) sb;
3577
3578         err = percpu_counter_init(&sbi->s_freeclusters_counter,
3579                         ext4_count_free_clusters(sb));
3580         if (!err) {
3581                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3582                                 ext4_count_free_inodes(sb));
3583         }
3584         if (!err) {
3585                 err = percpu_counter_init(&sbi->s_dirs_counter,
3586                                 ext4_count_dirs(sb));
3587         }
3588         if (!err) {
3589                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3590         }
3591         if (err) {
3592                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3593                 goto failed_mount3;
3594         }
3595
3596         sbi->s_stripe = ext4_get_stripe_size(sbi);
3597         sbi->s_max_writeback_mb_bump = 128;
3598
3599         /*
3600          * set up enough so that it can read an inode
3601          */
3602         if (!test_opt(sb, NOLOAD) &&
3603             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3604                 sb->s_op = &ext4_sops;
3605         else
3606                 sb->s_op = &ext4_nojournal_sops;
3607         sb->s_export_op = &ext4_export_ops;
3608         sb->s_xattr = ext4_xattr_handlers;
3609 #ifdef CONFIG_QUOTA
3610         sb->s_qcop = &ext4_qctl_operations;
3611         sb->dq_op = &ext4_quota_operations;
3612 #endif
3613         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3614
3615         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3616         mutex_init(&sbi->s_orphan_lock);
3617         sbi->s_resize_flags = 0;
3618
3619         sb->s_root = NULL;
3620
3621         needs_recovery = (es->s_last_orphan != 0 ||
3622                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3623                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3624
3625         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3626             !(sb->s_flags & MS_RDONLY))
3627                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3628                         goto failed_mount3;
3629
3630         /*
3631          * The first inode we look at is the journal inode.  Don't try
3632          * root first: it may be modified in the journal!
3633          */
3634         if (!test_opt(sb, NOLOAD) &&
3635             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3636                 if (ext4_load_journal(sb, es, journal_devnum))
3637                         goto failed_mount3;
3638         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3639               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3640                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3641                        "suppressed and not mounted read-only");
3642                 goto failed_mount_wq;
3643         } else {
3644                 clear_opt(sb, DATA_FLAGS);
3645                 sbi->s_journal = NULL;
3646                 needs_recovery = 0;
3647                 goto no_journal;
3648         }
3649
3650         if (ext4_blocks_count(es) > 0xffffffffULL &&
3651             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3652                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3653                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3654                 goto failed_mount_wq;
3655         }
3656
3657         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3658                 jbd2_journal_set_features(sbi->s_journal,
3659                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3660                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3661         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3662                 jbd2_journal_set_features(sbi->s_journal,
3663                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3664                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3665                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3666         } else {
3667                 jbd2_journal_clear_features(sbi->s_journal,
3668                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3669                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3670         }
3671
3672         /* We have now updated the journal if required, so we can
3673          * validate the data journaling mode. */
3674         switch (test_opt(sb, DATA_FLAGS)) {
3675         case 0:
3676                 /* No mode set, assume a default based on the journal
3677                  * capabilities: ORDERED_DATA if the journal can
3678                  * cope, else JOURNAL_DATA
3679                  */
3680                 if (jbd2_journal_check_available_features
3681                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3682                         set_opt(sb, ORDERED_DATA);
3683                 else
3684                         set_opt(sb, JOURNAL_DATA);
3685                 break;
3686
3687         case EXT4_MOUNT_ORDERED_DATA:
3688         case EXT4_MOUNT_WRITEBACK_DATA:
3689                 if (!jbd2_journal_check_available_features
3690                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3691                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3692                                "requested data journaling mode");
3693                         goto failed_mount_wq;
3694                 }
3695         default:
3696                 break;
3697         }
3698         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3699
3700         /*
3701          * The journal may have updated the bg summary counts, so we
3702          * need to update the global counters.
3703          */
3704         percpu_counter_set(&sbi->s_freeclusters_counter,
3705                            ext4_count_free_clusters(sb));
3706         percpu_counter_set(&sbi->s_freeinodes_counter,
3707                            ext4_count_free_inodes(sb));
3708         percpu_counter_set(&sbi->s_dirs_counter,
3709                            ext4_count_dirs(sb));
3710         percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3711
3712 no_journal:
3713         /*
3714          * The maximum number of concurrent works can be high and
3715          * concurrency isn't really necessary.  Limit it to 1.
3716          */
3717         EXT4_SB(sb)->dio_unwritten_wq =
3718                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3719         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3720                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3721                 goto failed_mount_wq;
3722         }
3723
3724         /*
3725          * The jbd2_journal_load will have done any necessary log recovery,
3726          * so we can safely mount the rest of the filesystem now.
3727          */
3728
3729         root = ext4_iget(sb, EXT4_ROOT_INO);
3730         if (IS_ERR(root)) {
3731                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3732                 ret = PTR_ERR(root);
3733                 root = NULL;
3734                 goto failed_mount4;
3735         }
3736         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3737                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3738                 goto failed_mount4;
3739         }
3740         sb->s_root = d_alloc_root(root);
3741         if (!sb->s_root) {
3742                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3743                 ret = -ENOMEM;
3744                 goto failed_mount4;
3745         }
3746
3747         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3748
3749         /* determine the minimum size of new large inodes, if present */
3750         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3751                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3752                                                      EXT4_GOOD_OLD_INODE_SIZE;
3753                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3754                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3755                         if (sbi->s_want_extra_isize <
3756                             le16_to_cpu(es->s_want_extra_isize))
3757                                 sbi->s_want_extra_isize =
3758                                         le16_to_cpu(es->s_want_extra_isize);
3759                         if (sbi->s_want_extra_isize <
3760                             le16_to_cpu(es->s_min_extra_isize))
3761                                 sbi->s_want_extra_isize =
3762                                         le16_to_cpu(es->s_min_extra_isize);
3763                 }
3764         }
3765         /* Check if enough inode space is available */
3766         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3767                                                         sbi->s_inode_size) {
3768                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3769                                                        EXT4_GOOD_OLD_INODE_SIZE;
3770                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3771                          "available");
3772         }
3773
3774         err = ext4_setup_system_zone(sb);
3775         if (err) {
3776                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3777                          "zone (%d)", err);
3778                 goto failed_mount4;
3779         }
3780
3781         ext4_ext_init(sb);
3782         err = ext4_mb_init(sb, needs_recovery);
3783         if (err) {
3784                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3785                          err);
3786                 goto failed_mount5;
3787         }
3788
3789         err = ext4_register_li_request(sb, first_not_zeroed);
3790         if (err)
3791                 goto failed_mount6;
3792
3793         sbi->s_kobj.kset = ext4_kset;
3794         init_completion(&sbi->s_kobj_unregister);
3795         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3796                                    "%s", sb->s_id);
3797         if (err)
3798                 goto failed_mount7;
3799
3800         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3801         ext4_orphan_cleanup(sb, es);
3802         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3803         if (needs_recovery) {
3804                 ext4_msg(sb, KERN_INFO, "recovery complete");
3805                 ext4_mark_recovery_complete(sb, es);
3806         }
3807         if (EXT4_SB(sb)->s_journal) {
3808                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3809                         descr = " journalled data mode";
3810                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3811                         descr = " ordered data mode";
3812                 else
3813                         descr = " writeback data mode";
3814         } else
3815                 descr = "out journal";
3816
3817         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3818                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3819                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3820
3821         if (es->s_error_count)
3822                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3823
3824         kfree(orig_data);
3825         return 0;
3826
3827 cantfind_ext4:
3828         if (!silent)
3829                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3830         goto failed_mount;
3831
3832 failed_mount7:
3833         ext4_unregister_li_request(sb);
3834 failed_mount6:
3835         ext4_ext_release(sb);
3836 failed_mount5:
3837         ext4_mb_release(sb);
3838         ext4_release_system_zone(sb);
3839 failed_mount4:
3840         iput(root);
3841         sb->s_root = NULL;
3842         ext4_msg(sb, KERN_ERR, "mount failed");
3843         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3844 failed_mount_wq:
3845         if (sbi->s_journal) {
3846                 jbd2_journal_destroy(sbi->s_journal);
3847                 sbi->s_journal = NULL;
3848         }
3849 failed_mount3:
3850         del_timer(&sbi->s_err_report);
3851         if (sbi->s_flex_groups)
3852                 ext4_kvfree(sbi->s_flex_groups);
3853         percpu_counter_destroy(&sbi->s_freeclusters_counter);
3854         percpu_counter_destroy(&sbi->s_freeinodes_counter);
3855         percpu_counter_destroy(&sbi->s_dirs_counter);
3856         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
3857         if (sbi->s_mmp_tsk)
3858                 kthread_stop(sbi->s_mmp_tsk);
3859 failed_mount2:
3860         for (i = 0; i < db_count; i++)
3861                 brelse(sbi->s_group_desc[i]);
3862         ext4_kvfree(sbi->s_group_desc);
3863 failed_mount:
3864         if (sbi->s_proc) {
3865                 remove_proc_entry(sb->s_id, ext4_proc_root);
3866         }
3867 #ifdef CONFIG_QUOTA
3868         for (i = 0; i < MAXQUOTAS; i++)
3869                 kfree(sbi->s_qf_names[i]);
3870 #endif
3871         ext4_blkdev_remove(sbi);
3872         brelse(bh);
3873 out_fail:
3874         sb->s_fs_info = NULL;
3875         kfree(sbi->s_blockgroup_lock);
3876         kfree(sbi);
3877 out_free_orig:
3878         kfree(orig_data);
3879         return ret;
3880 }
3881
3882 /*
3883  * Setup any per-fs journal parameters now.  We'll do this both on
3884  * initial mount, once the journal has been initialised but before we've
3885  * done any recovery; and again on any subsequent remount.
3886  */
3887 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3888 {
3889         struct ext4_sb_info *sbi = EXT4_SB(sb);
3890
3891         journal->j_commit_interval = sbi->s_commit_interval;
3892         journal->j_min_batch_time = sbi->s_min_batch_time;
3893         journal->j_max_batch_time = sbi->s_max_batch_time;
3894
3895         write_lock(&journal->j_state_lock);
3896         if (test_opt(sb, BARRIER))
3897                 journal->j_flags |= JBD2_BARRIER;
3898         else
3899                 journal->j_flags &= ~JBD2_BARRIER;
3900         if (test_opt(sb, DATA_ERR_ABORT))
3901                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3902         else
3903                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3904         write_unlock(&journal->j_state_lock);
3905 }
3906
3907 static journal_t *ext4_get_journal(struct super_block *sb,
3908                                    unsigned int journal_inum)
3909 {
3910         struct inode *journal_inode;
3911         journal_t *journal;
3912
3913         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3914
3915         /* First, test for the existence of a valid inode on disk.  Bad
3916          * things happen if we iget() an unused inode, as the subsequent
3917          * iput() will try to delete it. */
3918
3919         journal_inode = ext4_iget(sb, journal_inum);
3920         if (IS_ERR(journal_inode)) {
3921                 ext4_msg(sb, KERN_ERR, "no journal found");
3922                 return NULL;
3923         }
3924         if (!journal_inode->i_nlink) {
3925                 make_bad_inode(journal_inode);
3926                 iput(journal_inode);
3927                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3928                 return NULL;
3929         }
3930
3931         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3932                   journal_inode, journal_inode->i_size);
3933         if (!S_ISREG(journal_inode->i_mode)) {
3934                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3935                 iput(journal_inode);
3936                 return NULL;
3937         }
3938
3939         journal = jbd2_journal_init_inode(journal_inode);
3940         if (!journal) {
3941                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3942                 iput(journal_inode);
3943                 return NULL;
3944         }
3945         journal->j_private = sb;
3946         ext4_init_journal_params(sb, journal);
3947         return journal;
3948 }
3949
3950 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3951                                        dev_t j_dev)
3952 {
3953         struct buffer_head *bh;
3954         journal_t *journal;
3955         ext4_fsblk_t start;
3956         ext4_fsblk_t len;
3957         int hblock, blocksize;
3958         ext4_fsblk_t sb_block;
3959         unsigned long offset;
3960         struct ext4_super_block *es;
3961         struct block_device *bdev;
3962
3963         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3964
3965         bdev = ext4_blkdev_get(j_dev, sb);
3966         if (bdev == NULL)
3967                 return NULL;
3968
3969         blocksize = sb->s_blocksize;
3970         hblock = bdev_logical_block_size(bdev);
3971         if (blocksize < hblock) {
3972                 ext4_msg(sb, KERN_ERR,
3973                         "blocksize too small for journal device");
3974                 goto out_bdev;
3975         }
3976
3977         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3978         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3979         set_blocksize(bdev, blocksize);
3980         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3981                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3982                        "external journal");
3983                 goto out_bdev;
3984         }
3985
3986         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3987         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3988             !(le32_to_cpu(es->s_feature_incompat) &
3989               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3990                 ext4_msg(sb, KERN_ERR, "external journal has "
3991                                         "bad superblock");
3992                 brelse(bh);
3993                 goto out_bdev;
3994         }
3995
3996         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3997                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3998                 brelse(bh);
3999                 goto out_bdev;
4000         }
4001
4002         len = ext4_blocks_count(es);
4003         start = sb_block + 1;
4004         brelse(bh);     /* we're done with the superblock */
4005
4006         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4007                                         start, len, blocksize);
4008         if (!journal) {
4009                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4010                 goto out_bdev;
4011         }
4012         journal->j_private = sb;
4013         ll_rw_block(READ, 1, &journal->j_sb_buffer);
4014         wait_on_buffer(journal->j_sb_buffer);
4015         if (!buffer_uptodate(journal->j_sb_buffer)) {
4016                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4017                 goto out_journal;
4018         }
4019         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4020                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4021                                         "user (unsupported) - %d",
4022                         be32_to_cpu(journal->j_superblock->s_nr_users));
4023                 goto out_journal;
4024         }
4025         EXT4_SB(sb)->journal_bdev = bdev;
4026         ext4_init_journal_params(sb, journal);
4027         return journal;
4028
4029 out_journal:
4030         jbd2_journal_destroy(journal);
4031 out_bdev:
4032         ext4_blkdev_put(bdev);
4033         return NULL;
4034 }
4035
4036 static int ext4_load_journal(struct super_block *sb,
4037                              struct ext4_super_block *es,
4038                              unsigned long journal_devnum)
4039 {
4040         journal_t *journal;
4041         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4042         dev_t journal_dev;
4043         int err = 0;
4044         int really_read_only;
4045
4046         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4047
4048         if (journal_devnum &&
4049             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4050                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4051                         "numbers have changed");
4052                 journal_dev = new_decode_dev(journal_devnum);
4053         } else
4054                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4055
4056         really_read_only = bdev_read_only(sb->s_bdev);
4057
4058         /*
4059          * Are we loading a blank journal or performing recovery after a
4060          * crash?  For recovery, we need to check in advance whether we
4061          * can get read-write access to the device.
4062          */
4063         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4064                 if (sb->s_flags & MS_RDONLY) {
4065                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4066                                         "required on readonly filesystem");
4067                         if (really_read_only) {
4068                                 ext4_msg(sb, KERN_ERR, "write access "
4069                                         "unavailable, cannot proceed");
4070                                 return -EROFS;
4071                         }
4072                         ext4_msg(sb, KERN_INFO, "write access will "
4073                                "be enabled during recovery");
4074                 }
4075         }
4076
4077         if (journal_inum && journal_dev) {
4078                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4079                        "and inode journals!");
4080                 return -EINVAL;
4081         }
4082
4083         if (journal_inum) {
4084                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4085                         return -EINVAL;
4086         } else {
4087                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4088                         return -EINVAL;
4089         }
4090
4091         if (!(journal->j_flags & JBD2_BARRIER))
4092                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4093
4094         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
4095                 err = jbd2_journal_update_format(journal);
4096                 if (err)  {
4097                         ext4_msg(sb, KERN_ERR, "error updating journal");
4098                         jbd2_journal_destroy(journal);
4099                         return err;
4100                 }
4101         }
4102
4103         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4104                 err = jbd2_journal_wipe(journal, !really_read_only);
4105         if (!err) {
4106                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4107                 if (save)
4108                         memcpy(save, ((char *) es) +
4109                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4110                 err = jbd2_journal_load(journal);
4111                 if (save)
4112                         memcpy(((char *) es) + EXT4_S_ERR_START,
4113                                save, EXT4_S_ERR_LEN);
4114                 kfree(save);
4115         }
4116
4117         if (err) {
4118                 ext4_msg(sb, KERN_ERR, "error loading journal");
4119                 jbd2_journal_destroy(journal);
4120                 return err;
4121         }
4122
4123         EXT4_SB(sb)->s_journal = journal;
4124         ext4_clear_journal_err(sb, es);
4125
4126         if (!really_read_only && journal_devnum &&
4127             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4128                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4129
4130                 /* Make sure we flush the recovery flag to disk. */
4131                 ext4_commit_super(sb, 1);
4132         }
4133
4134         return 0;
4135 }
4136
4137 static int ext4_commit_super(struct super_block *sb, int sync)
4138 {
4139         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4140         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4141         int error = 0;
4142
4143         if (!sbh || block_device_ejected(sb))
4144                 return error;
4145         if (buffer_write_io_error(sbh)) {
4146                 /*
4147                  * Oh, dear.  A previous attempt to write the
4148                  * superblock failed.  This could happen because the
4149                  * USB device was yanked out.  Or it could happen to
4150                  * be a transient write error and maybe the block will
4151                  * be remapped.  Nothing we can do but to retry the
4152                  * write and hope for the best.
4153                  */
4154                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4155                        "superblock detected");
4156                 clear_buffer_write_io_error(sbh);
4157                 set_buffer_uptodate(sbh);
4158         }
4159         /*
4160          * If the file system is mounted read-only, don't update the
4161          * superblock write time.  This avoids updating the superblock
4162          * write time when we are mounting the root file system
4163          * read/only but we need to replay the journal; at that point,
4164          * for people who are east of GMT and who make their clock
4165          * tick in localtime for Windows bug-for-bug compatibility,
4166          * the clock is set in the future, and this will cause e2fsck
4167          * to complain and force a full file system check.
4168          */
4169         if (!(sb->s_flags & MS_RDONLY))
4170                 es->s_wtime = cpu_to_le32(get_seconds());
4171         if (sb->s_bdev->bd_part)
4172                 es->s_kbytes_written =
4173                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4174                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4175                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4176         else
4177                 es->s_kbytes_written =
4178                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4179         ext4_free_blocks_count_set(es,
4180                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4181                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4182         es->s_free_inodes_count =
4183                 cpu_to_le32(percpu_counter_sum_positive(
4184                                 &EXT4_SB(sb)->s_freeinodes_counter));
4185         sb->s_dirt = 0;
4186         BUFFER_TRACE(sbh, "marking dirty");
4187         mark_buffer_dirty(sbh);
4188         if (sync) {
4189                 error = sync_dirty_buffer(sbh);
4190                 if (error)
4191                         return error;
4192
4193                 error = buffer_write_io_error(sbh);
4194                 if (error) {
4195                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4196                                "superblock");
4197                         clear_buffer_write_io_error(sbh);
4198                         set_buffer_uptodate(sbh);
4199                 }
4200         }
4201         return error;
4202 }
4203
4204 /*
4205  * Have we just finished recovery?  If so, and if we are mounting (or
4206  * remounting) the filesystem readonly, then we will end up with a
4207  * consistent fs on disk.  Record that fact.
4208  */
4209 static void ext4_mark_recovery_complete(struct super_block *sb,
4210                                         struct ext4_super_block *es)
4211 {
4212         journal_t *journal = EXT4_SB(sb)->s_journal;
4213
4214         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4215                 BUG_ON(journal != NULL);
4216                 return;
4217         }
4218         jbd2_journal_lock_updates(journal);
4219         if (jbd2_journal_flush(journal) < 0)
4220                 goto out;
4221
4222         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4223             sb->s_flags & MS_RDONLY) {
4224                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4225                 ext4_commit_super(sb, 1);
4226         }
4227
4228 out:
4229         jbd2_journal_unlock_updates(journal);
4230 }
4231
4232 /*
4233  * If we are mounting (or read-write remounting) a filesystem whose journal
4234  * has recorded an error from a previous lifetime, move that error to the
4235  * main filesystem now.
4236  */
4237 static void ext4_clear_journal_err(struct super_block *sb,
4238                                    struct ext4_super_block *es)
4239 {
4240         journal_t *journal;
4241         int j_errno;
4242         const char *errstr;
4243
4244         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4245
4246         journal = EXT4_SB(sb)->s_journal;
4247
4248         /*
4249          * Now check for any error status which may have been recorded in the
4250          * journal by a prior ext4_error() or ext4_abort()
4251          */
4252
4253         j_errno = jbd2_journal_errno(journal);
4254         if (j_errno) {
4255                 char nbuf[16];
4256
4257                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4258                 ext4_warning(sb, "Filesystem error recorded "
4259                              "from previous mount: %s", errstr);
4260                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4261
4262                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4263                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4264                 ext4_commit_super(sb, 1);
4265
4266                 jbd2_journal_clear_err(journal);
4267         }
4268 }
4269
4270 /*
4271  * Force the running and committing transactions to commit,
4272  * and wait on the commit.
4273  */
4274 int ext4_force_commit(struct super_block *sb)
4275 {
4276         journal_t *journal;
4277         int ret = 0;
4278
4279         if (sb->s_flags & MS_RDONLY)
4280                 return 0;
4281
4282         journal = EXT4_SB(sb)->s_journal;
4283         if (journal) {
4284                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
4285                 ret = ext4_journal_force_commit(journal);
4286         }
4287
4288         return ret;
4289 }
4290
4291 static void ext4_write_super(struct super_block *sb)
4292 {
4293         lock_super(sb);
4294         ext4_commit_super(sb, 1);
4295         unlock_super(sb);
4296 }
4297
4298 static int ext4_sync_fs(struct super_block *sb, int wait)
4299 {
4300         int ret = 0;
4301         tid_t target;
4302         struct ext4_sb_info *sbi = EXT4_SB(sb);
4303
4304         trace_ext4_sync_fs(sb, wait);
4305         flush_workqueue(sbi->dio_unwritten_wq);
4306         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4307                 if (wait)
4308                         jbd2_log_wait_commit(sbi->s_journal, target);
4309         }
4310         return ret;
4311 }
4312
4313 /*
4314  * LVM calls this function before a (read-only) snapshot is created.  This
4315  * gives us a chance to flush the journal completely and mark the fs clean.
4316  *
4317  * Note that only this function cannot bring a filesystem to be in a clean
4318  * state independently, because ext4 prevents a new handle from being started
4319  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4320  * the upper layer.
4321  */
4322 static int ext4_freeze(struct super_block *sb)
4323 {
4324         int error = 0;
4325         journal_t *journal;
4326
4327         if (sb->s_flags & MS_RDONLY)
4328                 return 0;
4329
4330         journal = EXT4_SB(sb)->s_journal;
4331
4332         /* Now we set up the journal barrier. */
4333         jbd2_journal_lock_updates(journal);
4334
4335         /*
4336          * Don't clear the needs_recovery flag if we failed to flush
4337          * the journal.
4338          */
4339         error = jbd2_journal_flush(journal);
4340         if (error < 0)
4341                 goto out;
4342
4343         /* Journal blocked and flushed, clear needs_recovery flag. */
4344         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4345         error = ext4_commit_super(sb, 1);
4346 out:
4347         /* we rely on s_frozen to stop further updates */
4348         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4349         return error;
4350 }
4351
4352 /*
4353  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4354  * flag here, even though the filesystem is not technically dirty yet.
4355  */
4356 static int ext4_unfreeze(struct super_block *sb)
4357 {
4358         if (sb->s_flags & MS_RDONLY)
4359                 return 0;
4360
4361         lock_super(sb);
4362         /* Reset the needs_recovery flag before the fs is unlocked. */
4363         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4364         ext4_commit_super(sb, 1);
4365         unlock_super(sb);
4366         return 0;
4367 }
4368
4369 /*
4370  * Structure to save mount options for ext4_remount's benefit
4371  */
4372 struct ext4_mount_options {
4373         unsigned long s_mount_opt;
4374         unsigned long s_mount_opt2;
4375         uid_t s_resuid;
4376         gid_t s_resgid;
4377         unsigned long s_commit_interval;
4378         u32 s_min_batch_time, s_max_batch_time;
4379 #ifdef CONFIG_QUOTA
4380         int s_jquota_fmt;
4381         char *s_qf_names[MAXQUOTAS];
4382 #endif
4383 };
4384
4385 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4386 {
4387         struct ext4_super_block *es;
4388         struct ext4_sb_info *sbi = EXT4_SB(sb);
4389         ext4_fsblk_t n_blocks_count = 0;
4390         unsigned long old_sb_flags;
4391         struct ext4_mount_options old_opts;
4392         int enable_quota = 0;
4393         ext4_group_t g;
4394         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4395         int err = 0;
4396 #ifdef CONFIG_QUOTA
4397         int i;
4398 #endif
4399         char *orig_data = kstrdup(data, GFP_KERNEL);
4400
4401         /* Store the original options */
4402         lock_super(sb);
4403         old_sb_flags = sb->s_flags;
4404         old_opts.s_mount_opt = sbi->s_mount_opt;
4405         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4406         old_opts.s_resuid = sbi->s_resuid;
4407         old_opts.s_resgid = sbi->s_resgid;
4408         old_opts.s_commit_interval = sbi->s_commit_interval;
4409         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4410         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4411 #ifdef CONFIG_QUOTA
4412         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4413         for (i = 0; i < MAXQUOTAS; i++)
4414                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4415 #endif
4416         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4417                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4418
4419         /*
4420          * Allow the "check" option to be passed as a remount option.
4421          */
4422         if (!parse_options(data, sb, NULL, &journal_ioprio,
4423                            &n_blocks_count, 1)) {
4424                 err = -EINVAL;
4425                 goto restore_opts;
4426         }
4427
4428         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4429                 ext4_abort(sb, "Abort forced by user");
4430
4431         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4432                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4433
4434         es = sbi->s_es;
4435
4436         if (sbi->s_journal) {
4437                 ext4_init_journal_params(sb, sbi->s_journal);
4438                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4439         }
4440
4441         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4442                 n_blocks_count > ext4_blocks_count(es)) {
4443                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4444                         err = -EROFS;
4445                         goto restore_opts;
4446                 }
4447
4448                 if (*flags & MS_RDONLY) {
4449                         err = dquot_suspend(sb, -1);
4450                         if (err < 0)
4451                                 goto restore_opts;
4452
4453                         /*
4454                          * First of all, the unconditional stuff we have to do
4455                          * to disable replay of the journal when we next remount
4456                          */
4457                         sb->s_flags |= MS_RDONLY;
4458
4459                         /*
4460                          * OK, test if we are remounting a valid rw partition
4461                          * readonly, and if so set the rdonly flag and then
4462                          * mark the partition as valid again.
4463                          */
4464                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4465                             (sbi->s_mount_state & EXT4_VALID_FS))
4466                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4467
4468                         if (sbi->s_journal)
4469                                 ext4_mark_recovery_complete(sb, es);
4470                 } else {
4471                         /* Make sure we can mount this feature set readwrite */
4472                         if (!ext4_feature_set_ok(sb, 0)) {
4473                                 err = -EROFS;
4474                                 goto restore_opts;
4475                         }
4476                         /*
4477                          * Make sure the group descriptor checksums
4478                          * are sane.  If they aren't, refuse to remount r/w.
4479                          */
4480                         for (g = 0; g < sbi->s_groups_count; g++) {
4481                                 struct ext4_group_desc *gdp =
4482                                         ext4_get_group_desc(sb, g, NULL);
4483
4484                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4485                                         ext4_msg(sb, KERN_ERR,
4486                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4487                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4488                                                le16_to_cpu(gdp->bg_checksum));
4489                                         err = -EINVAL;
4490                                         goto restore_opts;
4491                                 }
4492                         }
4493
4494                         /*
4495                          * If we have an unprocessed orphan list hanging
4496                          * around from a previously readonly bdev mount,
4497                          * require a full umount/remount for now.
4498                          */
4499                         if (es->s_last_orphan) {
4500                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4501                                        "remount RDWR because of unprocessed "
4502                                        "orphan inode list.  Please "
4503                                        "umount/remount instead");
4504                                 err = -EINVAL;
4505                                 goto restore_opts;
4506                         }
4507
4508                         /*
4509                          * Mounting a RDONLY partition read-write, so reread
4510                          * and store the current valid flag.  (It may have
4511                          * been changed by e2fsck since we originally mounted
4512                          * the partition.)
4513                          */
4514                         if (sbi->s_journal)
4515                                 ext4_clear_journal_err(sb, es);
4516                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4517                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4518                                 goto restore_opts;
4519                         if (!ext4_setup_super(sb, es, 0))
4520                                 sb->s_flags &= ~MS_RDONLY;
4521                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4522                                                      EXT4_FEATURE_INCOMPAT_MMP))
4523                                 if (ext4_multi_mount_protect(sb,
4524                                                 le64_to_cpu(es->s_mmp_block))) {
4525                                         err = -EROFS;
4526                                         goto restore_opts;
4527                                 }
4528                         enable_quota = 1;
4529                 }
4530         }
4531
4532         /*
4533          * Reinitialize lazy itable initialization thread based on
4534          * current settings
4535          */
4536         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4537                 ext4_unregister_li_request(sb);
4538         else {
4539                 ext4_group_t first_not_zeroed;
4540                 first_not_zeroed = ext4_has_uninit_itable(sb);
4541                 ext4_register_li_request(sb, first_not_zeroed);
4542         }
4543
4544         ext4_setup_system_zone(sb);
4545         if (sbi->s_journal == NULL)
4546                 ext4_commit_super(sb, 1);
4547
4548 #ifdef CONFIG_QUOTA
4549         /* Release old quota file names */
4550         for (i = 0; i < MAXQUOTAS; i++)
4551                 if (old_opts.s_qf_names[i] &&
4552                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4553                         kfree(old_opts.s_qf_names[i]);
4554 #endif
4555         unlock_super(sb);
4556         if (enable_quota)
4557                 dquot_resume(sb, -1);
4558
4559         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4560         kfree(orig_data);
4561         return 0;
4562
4563 restore_opts:
4564         sb->s_flags = old_sb_flags;
4565         sbi->s_mount_opt = old_opts.s_mount_opt;
4566         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4567         sbi->s_resuid = old_opts.s_resuid;
4568         sbi->s_resgid = old_opts.s_resgid;
4569         sbi->s_commit_interval = old_opts.s_commit_interval;
4570         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4571         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4572 #ifdef CONFIG_QUOTA
4573         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4574         for (i = 0; i < MAXQUOTAS; i++) {
4575                 if (sbi->s_qf_names[i] &&
4576                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4577                         kfree(sbi->s_qf_names[i]);
4578                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4579         }
4580 #endif
4581         unlock_super(sb);
4582         kfree(orig_data);
4583         return err;
4584 }
4585
4586 /*
4587  * Note: calculating the overhead so we can be compatible with
4588  * historical BSD practice is quite difficult in the face of
4589  * clusters/bigalloc.  This is because multiple metadata blocks from
4590  * different block group can end up in the same allocation cluster.
4591  * Calculating the exact overhead in the face of clustered allocation
4592  * requires either O(all block bitmaps) in memory or O(number of block
4593  * groups**2) in time.  We will still calculate the superblock for
4594  * older file systems --- and if we come across with a bigalloc file
4595  * system with zero in s_overhead_clusters the estimate will be close to
4596  * correct especially for very large cluster sizes --- but for newer
4597  * file systems, it's better to calculate this figure once at mkfs
4598  * time, and store it in the superblock.  If the superblock value is
4599  * present (even for non-bigalloc file systems), we will use it.
4600  */
4601 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4602 {
4603         struct super_block *sb = dentry->d_sb;
4604         struct ext4_sb_info *sbi = EXT4_SB(sb);
4605         struct ext4_super_block *es = sbi->s_es;
4606         struct ext4_group_desc *gdp;
4607         u64 fsid;
4608         s64 bfree;
4609
4610         if (test_opt(sb, MINIX_DF)) {
4611                 sbi->s_overhead_last = 0;
4612         } else if (es->s_overhead_clusters) {
4613                 sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
4614         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4615                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4616                 ext4_fsblk_t overhead = 0;
4617
4618                 /*
4619                  * Compute the overhead (FS structures).  This is constant
4620                  * for a given filesystem unless the number of block groups
4621                  * changes so we cache the previous value until it does.
4622                  */
4623
4624                 /*
4625                  * All of the blocks before first_data_block are
4626                  * overhead
4627                  */
4628                 overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4629
4630                 /*
4631                  * Add the overhead found in each block group
4632                  */
4633                 for (i = 0; i < ngroups; i++) {
4634                         gdp = ext4_get_group_desc(sb, i, NULL);
4635                         overhead += ext4_num_overhead_clusters(sb, i, gdp);
4636                         cond_resched();
4637                 }
4638                 sbi->s_overhead_last = overhead;
4639                 smp_wmb();
4640                 sbi->s_blocks_last = ext4_blocks_count(es);
4641         }
4642
4643         buf->f_type = EXT4_SUPER_MAGIC;
4644         buf->f_bsize = sb->s_blocksize;
4645         buf->f_blocks = (ext4_blocks_count(es) -
4646                          EXT4_C2B(sbi, sbi->s_overhead_last));
4647         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4648                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4649         /* prevent underflow in case that few free space is available */
4650         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4651         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4652         if (buf->f_bfree < ext4_r_blocks_count(es))
4653                 buf->f_bavail = 0;
4654         buf->f_files = le32_to_cpu(es->s_inodes_count);
4655         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4656         buf->f_namelen = EXT4_NAME_LEN;
4657         fsid = le64_to_cpup((void *)es->s_uuid) ^
4658                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4659         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4660         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4661
4662         return 0;
4663 }
4664
4665 /* Helper function for writing quotas on sync - we need to start transaction
4666  * before quota file is locked for write. Otherwise the are possible deadlocks:
4667  * Process 1                         Process 2
4668  * ext4_create()                     quota_sync()
4669  *   jbd2_journal_start()                  write_dquot()
4670  *   dquot_initialize()                         down(dqio_mutex)
4671  *     down(dqio_mutex)                    jbd2_journal_start()
4672  *
4673  */
4674
4675 #ifdef CONFIG_QUOTA
4676
4677 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4678 {
4679         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4680 }
4681
4682 static int ext4_write_dquot(struct dquot *dquot)
4683 {
4684         int ret, err;
4685         handle_t *handle;
4686         struct inode *inode;
4687
4688         inode = dquot_to_inode(dquot);
4689         handle = ext4_journal_start(inode,
4690                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4691         if (IS_ERR(handle))
4692                 return PTR_ERR(handle);
4693         ret = dquot_commit(dquot);
4694         err = ext4_journal_stop(handle);
4695         if (!ret)
4696                 ret = err;
4697         return ret;
4698 }
4699
4700 static int ext4_acquire_dquot(struct dquot *dquot)
4701 {
4702         int ret, err;
4703         handle_t *handle;
4704
4705         handle = ext4_journal_start(dquot_to_inode(dquot),
4706                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4707         if (IS_ERR(handle))
4708                 return PTR_ERR(handle);
4709         ret = dquot_acquire(dquot);
4710         err = ext4_journal_stop(handle);
4711         if (!ret)
4712                 ret = err;
4713         return ret;
4714 }
4715
4716 static int ext4_release_dquot(struct dquot *dquot)
4717 {
4718         int ret, err;
4719         handle_t *handle;
4720
4721         handle = ext4_journal_start(dquot_to_inode(dquot),
4722                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4723         if (IS_ERR(handle)) {
4724                 /* Release dquot anyway to avoid endless cycle in dqput() */
4725                 dquot_release(dquot);
4726                 return PTR_ERR(handle);
4727         }
4728         ret = dquot_release(dquot);
4729         err = ext4_journal_stop(handle);
4730         if (!ret)
4731                 ret = err;
4732         return ret;
4733 }
4734
4735 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4736 {
4737         /* Are we journaling quotas? */
4738         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4739             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4740                 dquot_mark_dquot_dirty(dquot);
4741                 return ext4_write_dquot(dquot);
4742         } else {
4743                 return dquot_mark_dquot_dirty(dquot);
4744         }
4745 }
4746
4747 static int ext4_write_info(struct super_block *sb, int type)
4748 {
4749         int ret, err;
4750         handle_t *handle;
4751
4752         /* Data block + inode block */
4753         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4754         if (IS_ERR(handle))
4755                 return PTR_ERR(handle);
4756         ret = dquot_commit_info(sb, type);
4757         err = ext4_journal_stop(handle);
4758         if (!ret)
4759                 ret = err;
4760         return ret;
4761 }
4762
4763 /*
4764  * Turn on quotas during mount time - we need to find
4765  * the quota file and such...
4766  */
4767 static int ext4_quota_on_mount(struct super_block *sb, int type)
4768 {
4769         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4770                                         EXT4_SB(sb)->s_jquota_fmt, type);
4771 }
4772
4773 /*
4774  * Standard function to be called on quota_on
4775  */
4776 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4777                          struct path *path)
4778 {
4779         int err;
4780
4781         if (!test_opt(sb, QUOTA))
4782                 return -EINVAL;
4783
4784         /* Quotafile not on the same filesystem? */
4785         if (path->mnt->mnt_sb != sb)
4786                 return -EXDEV;
4787         /* Journaling quota? */
4788         if (EXT4_SB(sb)->s_qf_names[type]) {
4789                 /* Quotafile not in fs root? */
4790                 if (path->dentry->d_parent != sb->s_root)
4791                         ext4_msg(sb, KERN_WARNING,
4792                                 "Quota file not on filesystem root. "
4793                                 "Journaled quota will not work");
4794         }
4795
4796         /*
4797          * When we journal data on quota file, we have to flush journal to see
4798          * all updates to the file when we bypass pagecache...
4799          */
4800         if (EXT4_SB(sb)->s_journal &&
4801             ext4_should_journal_data(path->dentry->d_inode)) {
4802                 /*
4803                  * We don't need to lock updates but journal_flush() could
4804                  * otherwise be livelocked...
4805                  */
4806                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4807                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4808                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4809                 if (err)
4810                         return err;
4811         }
4812
4813         return dquot_quota_on(sb, type, format_id, path);
4814 }
4815
4816 static int ext4_quota_off(struct super_block *sb, int type)
4817 {
4818         struct inode *inode = sb_dqopt(sb)->files[type];
4819         handle_t *handle;
4820
4821         /* Force all delayed allocation blocks to be allocated.
4822          * Caller already holds s_umount sem */
4823         if (test_opt(sb, DELALLOC))
4824                 sync_filesystem(sb);
4825
4826         if (!inode)
4827                 goto out;
4828
4829         /* Update modification times of quota files when userspace can
4830          * start looking at them */
4831         handle = ext4_journal_start(inode, 1);
4832         if (IS_ERR(handle))
4833                 goto out;
4834         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4835         ext4_mark_inode_dirty(handle, inode);
4836         ext4_journal_stop(handle);
4837
4838 out:
4839         return dquot_quota_off(sb, type);
4840 }
4841
4842 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4843  * acquiring the locks... As quota files are never truncated and quota code
4844  * itself serializes the operations (and no one else should touch the files)
4845  * we don't have to be afraid of races */
4846 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4847                                size_t len, loff_t off)
4848 {
4849         struct inode *inode = sb_dqopt(sb)->files[type];
4850         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4851         int err = 0;
4852         int offset = off & (sb->s_blocksize - 1);
4853         int tocopy;
4854         size_t toread;
4855         struct buffer_head *bh;
4856         loff_t i_size = i_size_read(inode);
4857
4858         if (off > i_size)
4859                 return 0;
4860         if (off+len > i_size)
4861                 len = i_size-off;
4862         toread = len;
4863         while (toread > 0) {
4864                 tocopy = sb->s_blocksize - offset < toread ?
4865                                 sb->s_blocksize - offset : toread;
4866                 bh = ext4_bread(NULL, inode, blk, 0, &err);
4867                 if (err)
4868                         return err;
4869                 if (!bh)        /* A hole? */
4870                         memset(data, 0, tocopy);
4871                 else
4872                         memcpy(data, bh->b_data+offset, tocopy);
4873                 brelse(bh);
4874                 offset = 0;
4875                 toread -= tocopy;
4876                 data += tocopy;
4877                 blk++;
4878         }
4879         return len;
4880 }
4881
4882 /* Write to quotafile (we know the transaction is already started and has
4883  * enough credits) */
4884 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4885                                 const char *data, size_t len, loff_t off)
4886 {
4887         struct inode *inode = sb_dqopt(sb)->files[type];
4888         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4889         int err = 0;
4890         int offset = off & (sb->s_blocksize - 1);
4891         struct buffer_head *bh;
4892         handle_t *handle = journal_current_handle();
4893
4894         if (EXT4_SB(sb)->s_journal && !handle) {
4895                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4896                         " cancelled because transaction is not started",
4897                         (unsigned long long)off, (unsigned long long)len);
4898                 return -EIO;
4899         }
4900         /*
4901          * Since we account only one data block in transaction credits,
4902          * then it is impossible to cross a block boundary.
4903          */
4904         if (sb->s_blocksize - offset < len) {
4905                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4906                         " cancelled because not block aligned",
4907                         (unsigned long long)off, (unsigned long long)len);
4908                 return -EIO;
4909         }
4910
4911         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4912         bh = ext4_bread(handle, inode, blk, 1, &err);
4913         if (!bh)
4914                 goto out;
4915         err = ext4_journal_get_write_access(handle, bh);
4916         if (err) {
4917                 brelse(bh);
4918                 goto out;
4919         }
4920         lock_buffer(bh);
4921         memcpy(bh->b_data+offset, data, len);
4922         flush_dcache_page(bh->b_page);
4923         unlock_buffer(bh);
4924         err = ext4_handle_dirty_metadata(handle, NULL, bh);
4925         brelse(bh);
4926 out:
4927         if (err) {
4928                 mutex_unlock(&inode->i_mutex);
4929                 return err;
4930         }
4931         if (inode->i_size < off + len) {
4932                 i_size_write(inode, off + len);
4933                 EXT4_I(inode)->i_disksize = inode->i_size;
4934                 ext4_mark_inode_dirty(handle, inode);
4935         }
4936         mutex_unlock(&inode->i_mutex);
4937         return len;
4938 }
4939
4940 #endif
4941
4942 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4943                        const char *dev_name, void *data)
4944 {
4945         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4946 }
4947
4948 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4949 static inline void register_as_ext2(void)
4950 {
4951         int err = register_filesystem(&ext2_fs_type);
4952         if (err)
4953                 printk(KERN_WARNING
4954                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4955 }
4956
4957 static inline void unregister_as_ext2(void)
4958 {
4959         unregister_filesystem(&ext2_fs_type);
4960 }
4961
4962 static inline int ext2_feature_set_ok(struct super_block *sb)
4963 {
4964         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
4965                 return 0;
4966         if (sb->s_flags & MS_RDONLY)
4967                 return 1;
4968         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
4969                 return 0;
4970         return 1;
4971 }
4972 MODULE_ALIAS("ext2");
4973 #else
4974 static inline void register_as_ext2(void) { }
4975 static inline void unregister_as_ext2(void) { }
4976 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
4977 #endif
4978
4979 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4980 static inline void register_as_ext3(void)
4981 {
4982         int err = register_filesystem(&ext3_fs_type);
4983         if (err)
4984                 printk(KERN_WARNING
4985                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4986 }
4987
4988 static inline void unregister_as_ext3(void)
4989 {
4990         unregister_filesystem(&ext3_fs_type);
4991 }
4992
4993 static inline int ext3_feature_set_ok(struct super_block *sb)
4994 {
4995         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
4996                 return 0;
4997         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
4998                 return 0;
4999         if (sb->s_flags & MS_RDONLY)
5000                 return 1;
5001         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5002                 return 0;
5003         return 1;
5004 }
5005 MODULE_ALIAS("ext3");
5006 #else
5007 static inline void register_as_ext3(void) { }
5008 static inline void unregister_as_ext3(void) { }
5009 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5010 #endif
5011
5012 static struct file_system_type ext4_fs_type = {
5013         .owner          = THIS_MODULE,
5014         .name           = "ext4",
5015         .mount          = ext4_mount,
5016         .kill_sb        = kill_block_super,
5017         .fs_flags       = FS_REQUIRES_DEV,
5018 };
5019
5020 static int __init ext4_init_feat_adverts(void)
5021 {
5022         struct ext4_features *ef;
5023         int ret = -ENOMEM;
5024
5025         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5026         if (!ef)
5027                 goto out;
5028
5029         ef->f_kobj.kset = ext4_kset;
5030         init_completion(&ef->f_kobj_unregister);
5031         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5032                                    "features");
5033         if (ret) {
5034                 kfree(ef);
5035                 goto out;
5036         }
5037
5038         ext4_feat = ef;
5039         ret = 0;
5040 out:
5041         return ret;
5042 }
5043
5044 static void ext4_exit_feat_adverts(void)
5045 {
5046         kobject_put(&ext4_feat->f_kobj);
5047         wait_for_completion(&ext4_feat->f_kobj_unregister);
5048         kfree(ext4_feat);
5049 }
5050
5051 /* Shared across all ext4 file systems */
5052 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5053 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5054
5055 static int __init ext4_init_fs(void)
5056 {
5057         int i, err;
5058
5059         ext4_check_flag_values();
5060
5061         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5062                 mutex_init(&ext4__aio_mutex[i]);
5063                 init_waitqueue_head(&ext4__ioend_wq[i]);
5064         }
5065
5066         err = ext4_init_pageio();
5067         if (err)
5068                 return err;
5069         err = ext4_init_system_zone();
5070         if (err)
5071                 goto out6;
5072         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5073         if (!ext4_kset)
5074                 goto out5;
5075         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5076
5077         err = ext4_init_feat_adverts();
5078         if (err)
5079                 goto out4;
5080
5081         err = ext4_init_mballoc();
5082         if (err)
5083                 goto out3;
5084
5085         err = ext4_init_xattr();
5086         if (err)
5087                 goto out2;
5088         err = init_inodecache();
5089         if (err)
5090                 goto out1;
5091         register_as_ext3();
5092         register_as_ext2();
5093         err = register_filesystem(&ext4_fs_type);
5094         if (err)
5095                 goto out;
5096
5097         ext4_li_info = NULL;
5098         mutex_init(&ext4_li_mtx);
5099         return 0;
5100 out:
5101         unregister_as_ext2();
5102         unregister_as_ext3();
5103         destroy_inodecache();
5104 out1:
5105         ext4_exit_xattr();
5106 out2:
5107         ext4_exit_mballoc();
5108 out3:
5109         ext4_exit_feat_adverts();
5110 out4:
5111         if (ext4_proc_root)
5112                 remove_proc_entry("fs/ext4", NULL);
5113         kset_unregister(ext4_kset);
5114 out5:
5115         ext4_exit_system_zone();
5116 out6:
5117         ext4_exit_pageio();
5118         return err;
5119 }
5120
5121 static void __exit ext4_exit_fs(void)
5122 {
5123         ext4_destroy_lazyinit_thread();
5124         unregister_as_ext2();
5125         unregister_as_ext3();
5126         unregister_filesystem(&ext4_fs_type);
5127         destroy_inodecache();
5128         ext4_exit_xattr();
5129         ext4_exit_mballoc();
5130         ext4_exit_feat_adverts();
5131         remove_proc_entry("fs/ext4", NULL);
5132         kset_unregister(ext4_kset);
5133         ext4_exit_system_zone();
5134         ext4_exit_pageio();
5135 }
5136
5137 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5138 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5139 MODULE_LICENSE("GPL");
5140 module_init(ext4_init_fs)
5141 module_exit(ext4_exit_fs)