823e7d9deee273f7d66a31845dc6658c58a880f2
[pandora-kernel.git] / 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_jbd2.h"
49 #include "xattr.h"
50 #include "acl.h"
51 #include "mballoc.h"
52
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/ext4.h>
55
56 static struct proc_dir_entry *ext4_proc_root;
57 static struct kset *ext4_kset;
58 static struct ext4_lazy_init *ext4_li_info;
59 static struct mutex ext4_li_mtx;
60 static struct ext4_features *ext4_feat;
61
62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
63                              unsigned long journal_devnum);
64 static int ext4_commit_super(struct super_block *sb, int sync);
65 static void ext4_mark_recovery_complete(struct super_block *sb,
66                                         struct ext4_super_block *es);
67 static void ext4_clear_journal_err(struct super_block *sb,
68                                    struct ext4_super_block *es);
69 static int ext4_sync_fs(struct super_block *sb, int wait);
70 static const char *ext4_decode_error(struct super_block *sb, int errno,
71                                      char nbuf[16]);
72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
74 static int ext4_unfreeze(struct super_block *sb);
75 static void ext4_write_super(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78                        const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85
86 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
87 static struct file_system_type ext2_fs_type = {
88         .owner          = THIS_MODULE,
89         .name           = "ext2",
90         .mount          = ext4_mount,
91         .kill_sb        = kill_block_super,
92         .fs_flags       = FS_REQUIRES_DEV,
93 };
94 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
95 #else
96 #define IS_EXT2_SB(sb) (0)
97 #endif
98
99
100 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
101 static struct file_system_type ext3_fs_type = {
102         .owner          = THIS_MODULE,
103         .name           = "ext3",
104         .mount          = ext4_mount,
105         .kill_sb        = kill_block_super,
106         .fs_flags       = FS_REQUIRES_DEV,
107 };
108 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
109 #else
110 #define IS_EXT3_SB(sb) (0)
111 #endif
112
113 void *ext4_kvmalloc(size_t size, gfp_t flags)
114 {
115         void *ret;
116
117         ret = kmalloc(size, flags);
118         if (!ret)
119                 ret = __vmalloc(size, flags, PAGE_KERNEL);
120         return ret;
121 }
122
123 void *ext4_kvzalloc(size_t size, gfp_t flags)
124 {
125         void *ret;
126
127         ret = kzalloc(size, flags);
128         if (!ret)
129                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
130         return ret;
131 }
132
133 void ext4_kvfree(void *ptr)
134 {
135         if (is_vmalloc_addr(ptr))
136                 vfree(ptr);
137         else
138                 kfree(ptr);
139
140 }
141
142 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
143                                struct ext4_group_desc *bg)
144 {
145         return le32_to_cpu(bg->bg_block_bitmap_lo) |
146                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
147                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
148 }
149
150 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
151                                struct ext4_group_desc *bg)
152 {
153         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
154                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
155                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
156 }
157
158 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
159                               struct ext4_group_desc *bg)
160 {
161         return le32_to_cpu(bg->bg_inode_table_lo) |
162                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
163                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
164 }
165
166 __u32 ext4_free_blks_count(struct super_block *sb,
167                               struct ext4_group_desc *bg)
168 {
169         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
170                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
171                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
172 }
173
174 __u32 ext4_free_inodes_count(struct super_block *sb,
175                               struct ext4_group_desc *bg)
176 {
177         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
178                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
179                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
180 }
181
182 __u32 ext4_used_dirs_count(struct super_block *sb,
183                               struct ext4_group_desc *bg)
184 {
185         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
186                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
187                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
188 }
189
190 __u32 ext4_itable_unused_count(struct super_block *sb,
191                               struct ext4_group_desc *bg)
192 {
193         return le16_to_cpu(bg->bg_itable_unused_lo) |
194                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
195                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
196 }
197
198 void ext4_block_bitmap_set(struct super_block *sb,
199                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
200 {
201         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
202         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
203                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
204 }
205
206 void ext4_inode_bitmap_set(struct super_block *sb,
207                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
208 {
209         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
210         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
211                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
212 }
213
214 void ext4_inode_table_set(struct super_block *sb,
215                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
216 {
217         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
218         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
219                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
220 }
221
222 void ext4_free_blks_set(struct super_block *sb,
223                           struct ext4_group_desc *bg, __u32 count)
224 {
225         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
226         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
227                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
228 }
229
230 void ext4_free_inodes_set(struct super_block *sb,
231                           struct ext4_group_desc *bg, __u32 count)
232 {
233         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
234         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
235                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
236 }
237
238 void ext4_used_dirs_set(struct super_block *sb,
239                           struct ext4_group_desc *bg, __u32 count)
240 {
241         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
242         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
243                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
244 }
245
246 void ext4_itable_unused_set(struct super_block *sb,
247                           struct ext4_group_desc *bg, __u32 count)
248 {
249         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
250         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
251                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
252 }
253
254
255 /* Just increment the non-pointer handle value */
256 static handle_t *ext4_get_nojournal(void)
257 {
258         handle_t *handle = current->journal_info;
259         unsigned long ref_cnt = (unsigned long)handle;
260
261         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
262
263         ref_cnt++;
264         handle = (handle_t *)ref_cnt;
265
266         current->journal_info = handle;
267         return handle;
268 }
269
270
271 /* Decrement the non-pointer handle value */
272 static void ext4_put_nojournal(handle_t *handle)
273 {
274         unsigned long ref_cnt = (unsigned long)handle;
275
276         BUG_ON(ref_cnt == 0);
277
278         ref_cnt--;
279         handle = (handle_t *)ref_cnt;
280
281         current->journal_info = handle;
282 }
283
284 /*
285  * Wrappers for jbd2_journal_start/end.
286  *
287  * The only special thing we need to do here is to make sure that all
288  * journal_end calls result in the superblock being marked dirty, so
289  * that sync() will call the filesystem's write_super callback if
290  * appropriate.
291  *
292  * To avoid j_barrier hold in userspace when a user calls freeze(),
293  * ext4 prevents a new handle from being started by s_frozen, which
294  * is in an upper layer.
295  */
296 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
297 {
298         journal_t *journal;
299         handle_t  *handle;
300
301         trace_ext4_journal_start(sb, nblocks, _RET_IP_);
302         if (sb->s_flags & MS_RDONLY)
303                 return ERR_PTR(-EROFS);
304
305         journal = EXT4_SB(sb)->s_journal;
306         handle = ext4_journal_current_handle();
307
308         /*
309          * If a handle has been started, it should be allowed to
310          * finish, otherwise deadlock could happen between freeze
311          * and others(e.g. truncate) due to the restart of the
312          * journal handle if the filesystem is forzen and active
313          * handles are not stopped.
314          */
315         if (!handle)
316                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
317
318         if (!journal)
319                 return ext4_get_nojournal();
320         /*
321          * Special case here: if the journal has aborted behind our
322          * backs (eg. EIO in the commit thread), then we still need to
323          * take the FS itself readonly cleanly.
324          */
325         if (is_journal_aborted(journal)) {
326                 ext4_abort(sb, "Detected aborted journal");
327                 return ERR_PTR(-EROFS);
328         }
329         return jbd2_journal_start(journal, nblocks);
330 }
331
332 /*
333  * The only special thing we need to do here is to make sure that all
334  * jbd2_journal_stop calls result in the superblock being marked dirty, so
335  * that sync() will call the filesystem's write_super callback if
336  * appropriate.
337  */
338 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
339 {
340         struct super_block *sb;
341         int err;
342         int rc;
343
344         if (!ext4_handle_valid(handle)) {
345                 ext4_put_nojournal(handle);
346                 return 0;
347         }
348         sb = handle->h_transaction->t_journal->j_private;
349         err = handle->h_err;
350         rc = jbd2_journal_stop(handle);
351
352         if (!err)
353                 err = rc;
354         if (err)
355                 __ext4_std_error(sb, where, line, err);
356         return err;
357 }
358
359 void ext4_journal_abort_handle(const char *caller, unsigned int line,
360                                const char *err_fn, struct buffer_head *bh,
361                                handle_t *handle, int err)
362 {
363         char nbuf[16];
364         const char *errstr = ext4_decode_error(NULL, err, nbuf);
365
366         BUG_ON(!ext4_handle_valid(handle));
367
368         if (bh)
369                 BUFFER_TRACE(bh, "abort");
370
371         if (!handle->h_err)
372                 handle->h_err = err;
373
374         if (is_handle_aborted(handle))
375                 return;
376
377         printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
378                caller, line, errstr, err_fn);
379
380         jbd2_journal_abort_handle(handle);
381 }
382
383 static void __save_error_info(struct super_block *sb, const char *func,
384                             unsigned int line)
385 {
386         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
387
388         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
389         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
390         es->s_last_error_time = cpu_to_le32(get_seconds());
391         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
392         es->s_last_error_line = cpu_to_le32(line);
393         if (!es->s_first_error_time) {
394                 es->s_first_error_time = es->s_last_error_time;
395                 strncpy(es->s_first_error_func, func,
396                         sizeof(es->s_first_error_func));
397                 es->s_first_error_line = cpu_to_le32(line);
398                 es->s_first_error_ino = es->s_last_error_ino;
399                 es->s_first_error_block = es->s_last_error_block;
400         }
401         /*
402          * Start the daily error reporting function if it hasn't been
403          * started already
404          */
405         if (!es->s_error_count)
406                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
407         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
408 }
409
410 static void save_error_info(struct super_block *sb, const char *func,
411                             unsigned int line)
412 {
413         __save_error_info(sb, func, line);
414         ext4_commit_super(sb, 1);
415 }
416
417 /*
418  * The del_gendisk() function uninitializes the disk-specific data
419  * structures, including the bdi structure, without telling anyone
420  * else.  Once this happens, any attempt to call mark_buffer_dirty()
421  * (for example, by ext4_commit_super), will cause a kernel OOPS.
422  * This is a kludge to prevent these oops until we can put in a proper
423  * hook in del_gendisk() to inform the VFS and file system layers.
424  */
425 static int block_device_ejected(struct super_block *sb)
426 {
427         struct inode *bd_inode = sb->s_bdev->bd_inode;
428         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
429
430         return bdi->dev == NULL;
431 }
432
433
434 /* Deal with the reporting of failure conditions on a filesystem such as
435  * inconsistencies detected or read IO failures.
436  *
437  * On ext2, we can store the error state of the filesystem in the
438  * superblock.  That is not possible on ext4, because we may have other
439  * write ordering constraints on the superblock which prevent us from
440  * writing it out straight away; and given that the journal is about to
441  * be aborted, we can't rely on the current, or future, transactions to
442  * write out the superblock safely.
443  *
444  * We'll just use the jbd2_journal_abort() error code to record an error in
445  * the journal instead.  On recovery, the journal will complain about
446  * that error until we've noted it down and cleared it.
447  */
448
449 static void ext4_handle_error(struct super_block *sb)
450 {
451         if (sb->s_flags & MS_RDONLY)
452                 return;
453
454         if (!test_opt(sb, ERRORS_CONT)) {
455                 journal_t *journal = EXT4_SB(sb)->s_journal;
456
457                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
458                 if (journal)
459                         jbd2_journal_abort(journal, -EIO);
460         }
461         if (test_opt(sb, ERRORS_RO)) {
462                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
463                 sb->s_flags |= MS_RDONLY;
464         }
465         if (test_opt(sb, ERRORS_PANIC))
466                 panic("EXT4-fs (device %s): panic forced after error\n",
467                         sb->s_id);
468 }
469
470 void __ext4_error(struct super_block *sb, const char *function,
471                   unsigned int line, const char *fmt, ...)
472 {
473         struct va_format vaf;
474         va_list args;
475
476         va_start(args, fmt);
477         vaf.fmt = fmt;
478         vaf.va = &args;
479         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
480                sb->s_id, function, line, current->comm, &vaf);
481         va_end(args);
482
483         ext4_handle_error(sb);
484 }
485
486 void ext4_error_inode(struct inode *inode, const char *function,
487                       unsigned int line, ext4_fsblk_t block,
488                       const char *fmt, ...)
489 {
490         va_list args;
491         struct va_format vaf;
492         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
493
494         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
495         es->s_last_error_block = cpu_to_le64(block);
496         save_error_info(inode->i_sb, function, line);
497         va_start(args, fmt);
498         vaf.fmt = fmt;
499         vaf.va = &args;
500         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
501                inode->i_sb->s_id, function, line, inode->i_ino);
502         if (block)
503                 printk(KERN_CONT "block %llu: ", block);
504         printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
505         va_end(args);
506
507         ext4_handle_error(inode->i_sb);
508 }
509
510 void ext4_error_file(struct file *file, const char *function,
511                      unsigned int line, ext4_fsblk_t block,
512                      const char *fmt, ...)
513 {
514         va_list args;
515         struct va_format vaf;
516         struct ext4_super_block *es;
517         struct inode *inode = file->f_dentry->d_inode;
518         char pathname[80], *path;
519
520         es = EXT4_SB(inode->i_sb)->s_es;
521         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
522         save_error_info(inode->i_sb, function, line);
523         path = d_path(&(file->f_path), pathname, sizeof(pathname));
524         if (IS_ERR(path))
525                 path = "(unknown)";
526         printk(KERN_CRIT
527                "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
528                inode->i_sb->s_id, function, line, inode->i_ino);
529         if (block)
530                 printk(KERN_CONT "block %llu: ", block);
531         va_start(args, fmt);
532         vaf.fmt = fmt;
533         vaf.va = &args;
534         printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
535         va_end(args);
536
537         ext4_handle_error(inode->i_sb);
538 }
539
540 static const char *ext4_decode_error(struct super_block *sb, int errno,
541                                      char nbuf[16])
542 {
543         char *errstr = NULL;
544
545         switch (errno) {
546         case -EIO:
547                 errstr = "IO failure";
548                 break;
549         case -ENOMEM:
550                 errstr = "Out of memory";
551                 break;
552         case -EROFS:
553                 if (!sb || (EXT4_SB(sb)->s_journal &&
554                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
555                         errstr = "Journal has aborted";
556                 else
557                         errstr = "Readonly filesystem";
558                 break;
559         default:
560                 /* If the caller passed in an extra buffer for unknown
561                  * errors, textualise them now.  Else we just return
562                  * NULL. */
563                 if (nbuf) {
564                         /* Check for truncated error codes... */
565                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
566                                 errstr = nbuf;
567                 }
568                 break;
569         }
570
571         return errstr;
572 }
573
574 /* __ext4_std_error decodes expected errors from journaling functions
575  * automatically and invokes the appropriate error response.  */
576
577 void __ext4_std_error(struct super_block *sb, const char *function,
578                       unsigned int line, int errno)
579 {
580         char nbuf[16];
581         const char *errstr;
582
583         /* Special case: if the error is EROFS, and we're not already
584          * inside a transaction, then there's really no point in logging
585          * an error. */
586         if (errno == -EROFS && journal_current_handle() == NULL &&
587             (sb->s_flags & MS_RDONLY))
588                 return;
589
590         errstr = ext4_decode_error(sb, errno, nbuf);
591         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
592                sb->s_id, function, line, errstr);
593         save_error_info(sb, function, line);
594
595         ext4_handle_error(sb);
596 }
597
598 /*
599  * ext4_abort is a much stronger failure handler than ext4_error.  The
600  * abort function may be used to deal with unrecoverable failures such
601  * as journal IO errors or ENOMEM at a critical moment in log management.
602  *
603  * We unconditionally force the filesystem into an ABORT|READONLY state,
604  * unless the error response on the fs has been set to panic in which
605  * case we take the easy way out and panic immediately.
606  */
607
608 void __ext4_abort(struct super_block *sb, const char *function,
609                 unsigned int line, const char *fmt, ...)
610 {
611         va_list args;
612
613         save_error_info(sb, function, line);
614         va_start(args, fmt);
615         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
616                function, line);
617         vprintk(fmt, args);
618         printk("\n");
619         va_end(args);
620
621         if ((sb->s_flags & MS_RDONLY) == 0) {
622                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
623                 sb->s_flags |= MS_RDONLY;
624                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
625                 if (EXT4_SB(sb)->s_journal)
626                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
627                 save_error_info(sb, function, line);
628         }
629         if (test_opt(sb, ERRORS_PANIC))
630                 panic("EXT4-fs panic from previous error\n");
631 }
632
633 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
634 {
635         struct va_format vaf;
636         va_list args;
637
638         va_start(args, fmt);
639         vaf.fmt = fmt;
640         vaf.va = &args;
641         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
642         va_end(args);
643 }
644
645 void __ext4_warning(struct super_block *sb, const char *function,
646                     unsigned int line, const char *fmt, ...)
647 {
648         struct va_format vaf;
649         va_list args;
650
651         va_start(args, fmt);
652         vaf.fmt = fmt;
653         vaf.va = &args;
654         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
655                sb->s_id, function, line, &vaf);
656         va_end(args);
657 }
658
659 void __ext4_grp_locked_error(const char *function, unsigned int line,
660                              struct super_block *sb, ext4_group_t grp,
661                              unsigned long ino, ext4_fsblk_t block,
662                              const char *fmt, ...)
663 __releases(bitlock)
664 __acquires(bitlock)
665 {
666         struct va_format vaf;
667         va_list args;
668         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
669
670         es->s_last_error_ino = cpu_to_le32(ino);
671         es->s_last_error_block = cpu_to_le64(block);
672         __save_error_info(sb, function, line);
673
674         va_start(args, fmt);
675
676         vaf.fmt = fmt;
677         vaf.va = &args;
678         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
679                sb->s_id, function, line, grp);
680         if (ino)
681                 printk(KERN_CONT "inode %lu: ", ino);
682         if (block)
683                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
684         printk(KERN_CONT "%pV\n", &vaf);
685         va_end(args);
686
687         if (test_opt(sb, ERRORS_CONT)) {
688                 ext4_commit_super(sb, 0);
689                 return;
690         }
691
692         ext4_unlock_group(sb, grp);
693         ext4_handle_error(sb);
694         /*
695          * We only get here in the ERRORS_RO case; relocking the group
696          * may be dangerous, but nothing bad will happen since the
697          * filesystem will have already been marked read/only and the
698          * journal has been aborted.  We return 1 as a hint to callers
699          * who might what to use the return value from
700          * ext4_grp_locked_error() to distinguish between the
701          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
702          * aggressively from the ext4 function in question, with a
703          * more appropriate error code.
704          */
705         ext4_lock_group(sb, grp);
706         return;
707 }
708
709 void ext4_update_dynamic_rev(struct super_block *sb)
710 {
711         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
712
713         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
714                 return;
715
716         ext4_warning(sb,
717                      "updating to rev %d because of new feature flag, "
718                      "running e2fsck is recommended",
719                      EXT4_DYNAMIC_REV);
720
721         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
722         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
723         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
724         /* leave es->s_feature_*compat flags alone */
725         /* es->s_uuid will be set by e2fsck if empty */
726
727         /*
728          * The rest of the superblock fields should be zero, and if not it
729          * means they are likely already in use, so leave them alone.  We
730          * can leave it up to e2fsck to clean up any inconsistencies there.
731          */
732 }
733
734 /*
735  * Open the external journal device
736  */
737 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
738 {
739         struct block_device *bdev;
740         char b[BDEVNAME_SIZE];
741
742         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
743         if (IS_ERR(bdev))
744                 goto fail;
745         return bdev;
746
747 fail:
748         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
749                         __bdevname(dev, b), PTR_ERR(bdev));
750         return NULL;
751 }
752
753 /*
754  * Release the journal device
755  */
756 static int ext4_blkdev_put(struct block_device *bdev)
757 {
758         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
759 }
760
761 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
762 {
763         struct block_device *bdev;
764         int ret = -ENODEV;
765
766         bdev = sbi->journal_bdev;
767         if (bdev) {
768                 ret = ext4_blkdev_put(bdev);
769                 sbi->journal_bdev = NULL;
770         }
771         return ret;
772 }
773
774 static inline struct inode *orphan_list_entry(struct list_head *l)
775 {
776         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
777 }
778
779 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
780 {
781         struct list_head *l;
782
783         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
784                  le32_to_cpu(sbi->s_es->s_last_orphan));
785
786         printk(KERN_ERR "sb_info orphan list:\n");
787         list_for_each(l, &sbi->s_orphan) {
788                 struct inode *inode = orphan_list_entry(l);
789                 printk(KERN_ERR "  "
790                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
791                        inode->i_sb->s_id, inode->i_ino, inode,
792                        inode->i_mode, inode->i_nlink,
793                        NEXT_ORPHAN(inode));
794         }
795 }
796
797 static void ext4_put_super(struct super_block *sb)
798 {
799         struct ext4_sb_info *sbi = EXT4_SB(sb);
800         struct ext4_super_block *es = sbi->s_es;
801         int i, err;
802
803         ext4_unregister_li_request(sb);
804         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
805
806         flush_workqueue(sbi->dio_unwritten_wq);
807         destroy_workqueue(sbi->dio_unwritten_wq);
808
809         lock_super(sb);
810         if (sb->s_dirt)
811                 ext4_commit_super(sb, 1);
812
813         if (sbi->s_journal) {
814                 err = jbd2_journal_destroy(sbi->s_journal);
815                 sbi->s_journal = NULL;
816                 if (err < 0)
817                         ext4_abort(sb, "Couldn't clean up the journal");
818         }
819
820         del_timer(&sbi->s_err_report);
821         ext4_release_system_zone(sb);
822         ext4_mb_release(sb);
823         ext4_ext_release(sb);
824         ext4_xattr_put_super(sb);
825
826         if (!(sb->s_flags & MS_RDONLY)) {
827                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
828                 es->s_state = cpu_to_le16(sbi->s_mount_state);
829                 ext4_commit_super(sb, 1);
830         }
831         if (sbi->s_proc) {
832                 remove_proc_entry(sb->s_id, ext4_proc_root);
833         }
834         kobject_del(&sbi->s_kobj);
835
836         for (i = 0; i < sbi->s_gdb_count; i++)
837                 brelse(sbi->s_group_desc[i]);
838         ext4_kvfree(sbi->s_group_desc);
839         ext4_kvfree(sbi->s_flex_groups);
840         percpu_counter_destroy(&sbi->s_freeblocks_counter);
841         percpu_counter_destroy(&sbi->s_freeinodes_counter);
842         percpu_counter_destroy(&sbi->s_dirs_counter);
843         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
844         brelse(sbi->s_sbh);
845 #ifdef CONFIG_QUOTA
846         for (i = 0; i < MAXQUOTAS; i++)
847                 kfree(sbi->s_qf_names[i]);
848 #endif
849
850         /* Debugging code just in case the in-memory inode orphan list
851          * isn't empty.  The on-disk one can be non-empty if we've
852          * detected an error and taken the fs readonly, but the
853          * in-memory list had better be clean by this point. */
854         if (!list_empty(&sbi->s_orphan))
855                 dump_orphan_list(sb, sbi);
856         J_ASSERT(list_empty(&sbi->s_orphan));
857
858         invalidate_bdev(sb->s_bdev);
859         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
860                 /*
861                  * Invalidate the journal device's buffers.  We don't want them
862                  * floating about in memory - the physical journal device may
863                  * hotswapped, and it breaks the `ro-after' testing code.
864                  */
865                 sync_blockdev(sbi->journal_bdev);
866                 invalidate_bdev(sbi->journal_bdev);
867                 ext4_blkdev_remove(sbi);
868         }
869         if (sbi->s_mmp_tsk)
870                 kthread_stop(sbi->s_mmp_tsk);
871         sb->s_fs_info = NULL;
872         /*
873          * Now that we are completely done shutting down the
874          * superblock, we need to actually destroy the kobject.
875          */
876         unlock_super(sb);
877         kobject_put(&sbi->s_kobj);
878         wait_for_completion(&sbi->s_kobj_unregister);
879         kfree(sbi->s_blockgroup_lock);
880         kfree(sbi);
881 }
882
883 static struct kmem_cache *ext4_inode_cachep;
884
885 /*
886  * Called inside transaction, so use GFP_NOFS
887  */
888 static struct inode *ext4_alloc_inode(struct super_block *sb)
889 {
890         struct ext4_inode_info *ei;
891
892         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
893         if (!ei)
894                 return NULL;
895
896         ei->vfs_inode.i_version = 1;
897         ei->vfs_inode.i_data.writeback_index = 0;
898         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
899         INIT_LIST_HEAD(&ei->i_prealloc_list);
900         spin_lock_init(&ei->i_prealloc_lock);
901         ei->i_reserved_data_blocks = 0;
902         ei->i_reserved_meta_blocks = 0;
903         ei->i_allocated_meta_blocks = 0;
904         ei->i_da_metadata_calc_len = 0;
905         spin_lock_init(&(ei->i_block_reservation_lock));
906 #ifdef CONFIG_QUOTA
907         ei->i_reserved_quota = 0;
908 #endif
909         ei->jinode = NULL;
910         INIT_LIST_HEAD(&ei->i_completed_io_list);
911         spin_lock_init(&ei->i_completed_io_lock);
912         ei->cur_aio_dio = NULL;
913         ei->i_sync_tid = 0;
914         ei->i_datasync_tid = 0;
915         atomic_set(&ei->i_ioend_count, 0);
916         atomic_set(&ei->i_aiodio_unwritten, 0);
917
918         return &ei->vfs_inode;
919 }
920
921 static int ext4_drop_inode(struct inode *inode)
922 {
923         int drop = generic_drop_inode(inode);
924
925         trace_ext4_drop_inode(inode, drop);
926         return drop;
927 }
928
929 static void ext4_i_callback(struct rcu_head *head)
930 {
931         struct inode *inode = container_of(head, struct inode, i_rcu);
932         INIT_LIST_HEAD(&inode->i_dentry);
933         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
934 }
935
936 static void ext4_destroy_inode(struct inode *inode)
937 {
938         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
939                 ext4_msg(inode->i_sb, KERN_ERR,
940                          "Inode %lu (%p): orphan list check failed!",
941                          inode->i_ino, EXT4_I(inode));
942                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
943                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
944                                 true);
945                 dump_stack();
946         }
947         call_rcu(&inode->i_rcu, ext4_i_callback);
948 }
949
950 static void init_once(void *foo)
951 {
952         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
953
954         INIT_LIST_HEAD(&ei->i_orphan);
955 #ifdef CONFIG_EXT4_FS_XATTR
956         init_rwsem(&ei->xattr_sem);
957 #endif
958         init_rwsem(&ei->i_data_sem);
959         inode_init_once(&ei->vfs_inode);
960 }
961
962 static int init_inodecache(void)
963 {
964         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
965                                              sizeof(struct ext4_inode_info),
966                                              0, (SLAB_RECLAIM_ACCOUNT|
967                                                 SLAB_MEM_SPREAD),
968                                              init_once);
969         if (ext4_inode_cachep == NULL)
970                 return -ENOMEM;
971         return 0;
972 }
973
974 static void destroy_inodecache(void)
975 {
976         kmem_cache_destroy(ext4_inode_cachep);
977 }
978
979 void ext4_clear_inode(struct inode *inode)
980 {
981         invalidate_inode_buffers(inode);
982         end_writeback(inode);
983         dquot_drop(inode);
984         ext4_discard_preallocations(inode);
985         if (EXT4_I(inode)->jinode) {
986                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
987                                                EXT4_I(inode)->jinode);
988                 jbd2_free_inode(EXT4_I(inode)->jinode);
989                 EXT4_I(inode)->jinode = NULL;
990         }
991 }
992
993 static inline void ext4_show_quota_options(struct seq_file *seq,
994                                            struct super_block *sb)
995 {
996 #if defined(CONFIG_QUOTA)
997         struct ext4_sb_info *sbi = EXT4_SB(sb);
998
999         if (sbi->s_jquota_fmt) {
1000                 char *fmtname = "";
1001
1002                 switch (sbi->s_jquota_fmt) {
1003                 case QFMT_VFS_OLD:
1004                         fmtname = "vfsold";
1005                         break;
1006                 case QFMT_VFS_V0:
1007                         fmtname = "vfsv0";
1008                         break;
1009                 case QFMT_VFS_V1:
1010                         fmtname = "vfsv1";
1011                         break;
1012                 }
1013                 seq_printf(seq, ",jqfmt=%s", fmtname);
1014         }
1015
1016         if (sbi->s_qf_names[USRQUOTA])
1017                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1018
1019         if (sbi->s_qf_names[GRPQUOTA])
1020                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1021
1022         if (test_opt(sb, USRQUOTA))
1023                 seq_puts(seq, ",usrquota");
1024
1025         if (test_opt(sb, GRPQUOTA))
1026                 seq_puts(seq, ",grpquota");
1027 #endif
1028 }
1029
1030 /*
1031  * Show an option if
1032  *  - it's set to a non-default value OR
1033  *  - if the per-sb default is different from the global default
1034  */
1035 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
1036 {
1037         int def_errors;
1038         unsigned long def_mount_opts;
1039         struct super_block *sb = vfs->mnt_sb;
1040         struct ext4_sb_info *sbi = EXT4_SB(sb);
1041         struct ext4_super_block *es = sbi->s_es;
1042
1043         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1044         def_errors     = le16_to_cpu(es->s_errors);
1045
1046         if (sbi->s_sb_block != 1)
1047                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
1048         if (test_opt(sb, MINIX_DF))
1049                 seq_puts(seq, ",minixdf");
1050         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
1051                 seq_puts(seq, ",grpid");
1052         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
1053                 seq_puts(seq, ",nogrpid");
1054         if (sbi->s_resuid != EXT4_DEF_RESUID ||
1055             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
1056                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
1057         }
1058         if (sbi->s_resgid != EXT4_DEF_RESGID ||
1059             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
1060                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
1061         }
1062         if (test_opt(sb, ERRORS_RO)) {
1063                 if (def_errors == EXT4_ERRORS_PANIC ||
1064                     def_errors == EXT4_ERRORS_CONTINUE) {
1065                         seq_puts(seq, ",errors=remount-ro");
1066                 }
1067         }
1068         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1069                 seq_puts(seq, ",errors=continue");
1070         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1071                 seq_puts(seq, ",errors=panic");
1072         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
1073                 seq_puts(seq, ",nouid32");
1074         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
1075                 seq_puts(seq, ",debug");
1076         if (test_opt(sb, OLDALLOC))
1077                 seq_puts(seq, ",oldalloc");
1078 #ifdef CONFIG_EXT4_FS_XATTR
1079         if (test_opt(sb, XATTR_USER))
1080                 seq_puts(seq, ",user_xattr");
1081         if (!test_opt(sb, XATTR_USER))
1082                 seq_puts(seq, ",nouser_xattr");
1083 #endif
1084 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1085         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1086                 seq_puts(seq, ",acl");
1087         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1088                 seq_puts(seq, ",noacl");
1089 #endif
1090         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1091                 seq_printf(seq, ",commit=%u",
1092                            (unsigned) (sbi->s_commit_interval / HZ));
1093         }
1094         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1095                 seq_printf(seq, ",min_batch_time=%u",
1096                            (unsigned) sbi->s_min_batch_time);
1097         }
1098         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1099                 seq_printf(seq, ",max_batch_time=%u",
1100                            (unsigned) sbi->s_min_batch_time);
1101         }
1102
1103         /*
1104          * We're changing the default of barrier mount option, so
1105          * let's always display its mount state so it's clear what its
1106          * status is.
1107          */
1108         seq_puts(seq, ",barrier=");
1109         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1110         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1111                 seq_puts(seq, ",journal_async_commit");
1112         else if (test_opt(sb, JOURNAL_CHECKSUM))
1113                 seq_puts(seq, ",journal_checksum");
1114         if (test_opt(sb, I_VERSION))
1115                 seq_puts(seq, ",i_version");
1116         if (!test_opt(sb, DELALLOC) &&
1117             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1118                 seq_puts(seq, ",nodelalloc");
1119
1120         if (!test_opt(sb, MBLK_IO_SUBMIT))
1121                 seq_puts(seq, ",nomblk_io_submit");
1122         if (sbi->s_stripe)
1123                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1124         /*
1125          * journal mode get enabled in different ways
1126          * So just print the value even if we didn't specify it
1127          */
1128         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1129                 seq_puts(seq, ",data=journal");
1130         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1131                 seq_puts(seq, ",data=ordered");
1132         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1133                 seq_puts(seq, ",data=writeback");
1134
1135         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1136                 seq_printf(seq, ",inode_readahead_blks=%u",
1137                            sbi->s_inode_readahead_blks);
1138
1139         if (test_opt(sb, DATA_ERR_ABORT))
1140                 seq_puts(seq, ",data_err=abort");
1141
1142         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1143                 seq_puts(seq, ",noauto_da_alloc");
1144
1145         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1146                 seq_puts(seq, ",discard");
1147
1148         if (test_opt(sb, NOLOAD))
1149                 seq_puts(seq, ",norecovery");
1150
1151         if (test_opt(sb, DIOREAD_NOLOCK))
1152                 seq_puts(seq, ",dioread_nolock");
1153
1154         if (test_opt(sb, BLOCK_VALIDITY) &&
1155             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1156                 seq_puts(seq, ",block_validity");
1157
1158         if (!test_opt(sb, INIT_INODE_TABLE))
1159                 seq_puts(seq, ",noinit_inode_table");
1160         else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
1161                 seq_printf(seq, ",init_inode_table=%u",
1162                            (unsigned) sbi->s_li_wait_mult);
1163
1164         ext4_show_quota_options(seq, sb);
1165
1166         return 0;
1167 }
1168
1169 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1170                                         u64 ino, u32 generation)
1171 {
1172         struct inode *inode;
1173
1174         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1175                 return ERR_PTR(-ESTALE);
1176         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1177                 return ERR_PTR(-ESTALE);
1178
1179         /* iget isn't really right if the inode is currently unallocated!!
1180          *
1181          * ext4_read_inode will return a bad_inode if the inode had been
1182          * deleted, so we should be safe.
1183          *
1184          * Currently we don't know the generation for parent directory, so
1185          * a generation of 0 means "accept any"
1186          */
1187         inode = ext4_iget(sb, ino);
1188         if (IS_ERR(inode))
1189                 return ERR_CAST(inode);
1190         if (generation && inode->i_generation != generation) {
1191                 iput(inode);
1192                 return ERR_PTR(-ESTALE);
1193         }
1194
1195         return inode;
1196 }
1197
1198 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1199                                         int fh_len, int fh_type)
1200 {
1201         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1202                                     ext4_nfs_get_inode);
1203 }
1204
1205 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1206                                         int fh_len, int fh_type)
1207 {
1208         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1209                                     ext4_nfs_get_inode);
1210 }
1211
1212 /*
1213  * Try to release metadata pages (indirect blocks, directories) which are
1214  * mapped via the block device.  Since these pages could have journal heads
1215  * which would prevent try_to_free_buffers() from freeing them, we must use
1216  * jbd2 layer's try_to_free_buffers() function to release them.
1217  */
1218 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1219                                  gfp_t wait)
1220 {
1221         journal_t *journal = EXT4_SB(sb)->s_journal;
1222
1223         WARN_ON(PageChecked(page));
1224         if (!page_has_buffers(page))
1225                 return 0;
1226         if (journal)
1227                 return jbd2_journal_try_to_free_buffers(journal, page,
1228                                                         wait & ~__GFP_WAIT);
1229         return try_to_free_buffers(page);
1230 }
1231
1232 #ifdef CONFIG_QUOTA
1233 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1234 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1235
1236 static int ext4_write_dquot(struct dquot *dquot);
1237 static int ext4_acquire_dquot(struct dquot *dquot);
1238 static int ext4_release_dquot(struct dquot *dquot);
1239 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1240 static int ext4_write_info(struct super_block *sb, int type);
1241 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1242                          struct path *path);
1243 static int ext4_quota_off(struct super_block *sb, int type);
1244 static int ext4_quota_on_mount(struct super_block *sb, int type);
1245 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1246                                size_t len, loff_t off);
1247 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1248                                 const char *data, size_t len, loff_t off);
1249
1250 static const struct dquot_operations ext4_quota_operations = {
1251         .get_reserved_space = ext4_get_reserved_space,
1252         .write_dquot    = ext4_write_dquot,
1253         .acquire_dquot  = ext4_acquire_dquot,
1254         .release_dquot  = ext4_release_dquot,
1255         .mark_dirty     = ext4_mark_dquot_dirty,
1256         .write_info     = ext4_write_info,
1257         .alloc_dquot    = dquot_alloc,
1258         .destroy_dquot  = dquot_destroy,
1259 };
1260
1261 static const struct quotactl_ops ext4_qctl_operations = {
1262         .quota_on       = ext4_quota_on,
1263         .quota_off      = ext4_quota_off,
1264         .quota_sync     = dquot_quota_sync,
1265         .get_info       = dquot_get_dqinfo,
1266         .set_info       = dquot_set_dqinfo,
1267         .get_dqblk      = dquot_get_dqblk,
1268         .set_dqblk      = dquot_set_dqblk
1269 };
1270 #endif
1271
1272 static const struct super_operations ext4_sops = {
1273         .alloc_inode    = ext4_alloc_inode,
1274         .destroy_inode  = ext4_destroy_inode,
1275         .write_inode    = ext4_write_inode,
1276         .dirty_inode    = ext4_dirty_inode,
1277         .drop_inode     = ext4_drop_inode,
1278         .evict_inode    = ext4_evict_inode,
1279         .put_super      = ext4_put_super,
1280         .sync_fs        = ext4_sync_fs,
1281         .freeze_fs      = ext4_freeze,
1282         .unfreeze_fs    = ext4_unfreeze,
1283         .statfs         = ext4_statfs,
1284         .remount_fs     = ext4_remount,
1285         .show_options   = ext4_show_options,
1286 #ifdef CONFIG_QUOTA
1287         .quota_read     = ext4_quota_read,
1288         .quota_write    = ext4_quota_write,
1289 #endif
1290         .bdev_try_to_free_page = bdev_try_to_free_page,
1291 };
1292
1293 static const struct super_operations ext4_nojournal_sops = {
1294         .alloc_inode    = ext4_alloc_inode,
1295         .destroy_inode  = ext4_destroy_inode,
1296         .write_inode    = ext4_write_inode,
1297         .dirty_inode    = ext4_dirty_inode,
1298         .drop_inode     = ext4_drop_inode,
1299         .evict_inode    = ext4_evict_inode,
1300         .write_super    = ext4_write_super,
1301         .put_super      = ext4_put_super,
1302         .statfs         = ext4_statfs,
1303         .remount_fs     = ext4_remount,
1304         .show_options   = ext4_show_options,
1305 #ifdef CONFIG_QUOTA
1306         .quota_read     = ext4_quota_read,
1307         .quota_write    = ext4_quota_write,
1308 #endif
1309         .bdev_try_to_free_page = bdev_try_to_free_page,
1310 };
1311
1312 static const struct export_operations ext4_export_ops = {
1313         .fh_to_dentry = ext4_fh_to_dentry,
1314         .fh_to_parent = ext4_fh_to_parent,
1315         .get_parent = ext4_get_parent,
1316 };
1317
1318 enum {
1319         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1320         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1321         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1322         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1323         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1324         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1325         Opt_journal_update, Opt_journal_dev,
1326         Opt_journal_checksum, Opt_journal_async_commit,
1327         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1328         Opt_data_err_abort, Opt_data_err_ignore,
1329         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1330         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1331         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1332         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1333         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1334         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1335         Opt_inode_readahead_blks, Opt_journal_ioprio,
1336         Opt_dioread_nolock, Opt_dioread_lock,
1337         Opt_discard, Opt_nodiscard,
1338         Opt_init_inode_table, Opt_noinit_inode_table,
1339 };
1340
1341 static const match_table_t tokens = {
1342         {Opt_bsd_df, "bsddf"},
1343         {Opt_minix_df, "minixdf"},
1344         {Opt_grpid, "grpid"},
1345         {Opt_grpid, "bsdgroups"},
1346         {Opt_nogrpid, "nogrpid"},
1347         {Opt_nogrpid, "sysvgroups"},
1348         {Opt_resgid, "resgid=%u"},
1349         {Opt_resuid, "resuid=%u"},
1350         {Opt_sb, "sb=%u"},
1351         {Opt_err_cont, "errors=continue"},
1352         {Opt_err_panic, "errors=panic"},
1353         {Opt_err_ro, "errors=remount-ro"},
1354         {Opt_nouid32, "nouid32"},
1355         {Opt_debug, "debug"},
1356         {Opt_oldalloc, "oldalloc"},
1357         {Opt_orlov, "orlov"},
1358         {Opt_user_xattr, "user_xattr"},
1359         {Opt_nouser_xattr, "nouser_xattr"},
1360         {Opt_acl, "acl"},
1361         {Opt_noacl, "noacl"},
1362         {Opt_noload, "noload"},
1363         {Opt_noload, "norecovery"},
1364         {Opt_nobh, "nobh"},
1365         {Opt_bh, "bh"},
1366         {Opt_commit, "commit=%u"},
1367         {Opt_min_batch_time, "min_batch_time=%u"},
1368         {Opt_max_batch_time, "max_batch_time=%u"},
1369         {Opt_journal_update, "journal=update"},
1370         {Opt_journal_dev, "journal_dev=%u"},
1371         {Opt_journal_checksum, "journal_checksum"},
1372         {Opt_journal_async_commit, "journal_async_commit"},
1373         {Opt_abort, "abort"},
1374         {Opt_data_journal, "data=journal"},
1375         {Opt_data_ordered, "data=ordered"},
1376         {Opt_data_writeback, "data=writeback"},
1377         {Opt_data_err_abort, "data_err=abort"},
1378         {Opt_data_err_ignore, "data_err=ignore"},
1379         {Opt_offusrjquota, "usrjquota="},
1380         {Opt_usrjquota, "usrjquota=%s"},
1381         {Opt_offgrpjquota, "grpjquota="},
1382         {Opt_grpjquota, "grpjquota=%s"},
1383         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1384         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1385         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1386         {Opt_grpquota, "grpquota"},
1387         {Opt_noquota, "noquota"},
1388         {Opt_quota, "quota"},
1389         {Opt_usrquota, "usrquota"},
1390         {Opt_barrier, "barrier=%u"},
1391         {Opt_barrier, "barrier"},
1392         {Opt_nobarrier, "nobarrier"},
1393         {Opt_i_version, "i_version"},
1394         {Opt_stripe, "stripe=%u"},
1395         {Opt_resize, "resize"},
1396         {Opt_delalloc, "delalloc"},
1397         {Opt_nodelalloc, "nodelalloc"},
1398         {Opt_mblk_io_submit, "mblk_io_submit"},
1399         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1400         {Opt_block_validity, "block_validity"},
1401         {Opt_noblock_validity, "noblock_validity"},
1402         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1403         {Opt_journal_ioprio, "journal_ioprio=%u"},
1404         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1405         {Opt_auto_da_alloc, "auto_da_alloc"},
1406         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1407         {Opt_dioread_nolock, "dioread_nolock"},
1408         {Opt_dioread_lock, "dioread_lock"},
1409         {Opt_discard, "discard"},
1410         {Opt_nodiscard, "nodiscard"},
1411         {Opt_init_inode_table, "init_itable=%u"},
1412         {Opt_init_inode_table, "init_itable"},
1413         {Opt_noinit_inode_table, "noinit_itable"},
1414         {Opt_err, NULL},
1415 };
1416
1417 static ext4_fsblk_t get_sb_block(void **data)
1418 {
1419         ext4_fsblk_t    sb_block;
1420         char            *options = (char *) *data;
1421
1422         if (!options || strncmp(options, "sb=", 3) != 0)
1423                 return 1;       /* Default location */
1424
1425         options += 3;
1426         /* TODO: use simple_strtoll with >32bit ext4 */
1427         sb_block = simple_strtoul(options, &options, 0);
1428         if (*options && *options != ',') {
1429                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1430                        (char *) *data);
1431                 return 1;
1432         }
1433         if (*options == ',')
1434                 options++;
1435         *data = (void *) options;
1436
1437         return sb_block;
1438 }
1439
1440 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1441 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1442         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1443
1444 #ifdef CONFIG_QUOTA
1445 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1446 {
1447         struct ext4_sb_info *sbi = EXT4_SB(sb);
1448         char *qname;
1449
1450         if (sb_any_quota_loaded(sb) &&
1451                 !sbi->s_qf_names[qtype]) {
1452                 ext4_msg(sb, KERN_ERR,
1453                         "Cannot change journaled "
1454                         "quota options when quota turned on");
1455                 return 0;
1456         }
1457         qname = match_strdup(args);
1458         if (!qname) {
1459                 ext4_msg(sb, KERN_ERR,
1460                         "Not enough memory for storing quotafile name");
1461                 return 0;
1462         }
1463         if (sbi->s_qf_names[qtype] &&
1464                 strcmp(sbi->s_qf_names[qtype], qname)) {
1465                 ext4_msg(sb, KERN_ERR,
1466                         "%s quota file already specified", QTYPE2NAME(qtype));
1467                 kfree(qname);
1468                 return 0;
1469         }
1470         sbi->s_qf_names[qtype] = qname;
1471         if (strchr(sbi->s_qf_names[qtype], '/')) {
1472                 ext4_msg(sb, KERN_ERR,
1473                         "quotafile must be on filesystem root");
1474                 kfree(sbi->s_qf_names[qtype]);
1475                 sbi->s_qf_names[qtype] = NULL;
1476                 return 0;
1477         }
1478         set_opt(sb, QUOTA);
1479         return 1;
1480 }
1481
1482 static int clear_qf_name(struct super_block *sb, int qtype)
1483 {
1484
1485         struct ext4_sb_info *sbi = EXT4_SB(sb);
1486
1487         if (sb_any_quota_loaded(sb) &&
1488                 sbi->s_qf_names[qtype]) {
1489                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1490                         " when quota turned on");
1491                 return 0;
1492         }
1493         /*
1494          * The space will be released later when all options are confirmed
1495          * to be correct
1496          */
1497         sbi->s_qf_names[qtype] = NULL;
1498         return 1;
1499 }
1500 #endif
1501
1502 static int parse_options(char *options, struct super_block *sb,
1503                          unsigned long *journal_devnum,
1504                          unsigned int *journal_ioprio,
1505                          ext4_fsblk_t *n_blocks_count, int is_remount)
1506 {
1507         struct ext4_sb_info *sbi = EXT4_SB(sb);
1508         char *p;
1509         substring_t args[MAX_OPT_ARGS];
1510         int data_opt = 0;
1511         int option;
1512 #ifdef CONFIG_QUOTA
1513         int qfmt;
1514 #endif
1515
1516         if (!options)
1517                 return 1;
1518
1519         while ((p = strsep(&options, ",")) != NULL) {
1520                 int token;
1521                 if (!*p)
1522                         continue;
1523
1524                 /*
1525                  * Initialize args struct so we know whether arg was
1526                  * found; some options take optional arguments.
1527                  */
1528                 args[0].to = args[0].from = NULL;
1529                 token = match_token(p, tokens, args);
1530                 switch (token) {
1531                 case Opt_bsd_df:
1532                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1533                         clear_opt(sb, MINIX_DF);
1534                         break;
1535                 case Opt_minix_df:
1536                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1537                         set_opt(sb, MINIX_DF);
1538
1539                         break;
1540                 case Opt_grpid:
1541                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1542                         set_opt(sb, GRPID);
1543
1544                         break;
1545                 case Opt_nogrpid:
1546                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1547                         clear_opt(sb, GRPID);
1548
1549                         break;
1550                 case Opt_resuid:
1551                         if (match_int(&args[0], &option))
1552                                 return 0;
1553                         sbi->s_resuid = option;
1554                         break;
1555                 case Opt_resgid:
1556                         if (match_int(&args[0], &option))
1557                                 return 0;
1558                         sbi->s_resgid = option;
1559                         break;
1560                 case Opt_sb:
1561                         /* handled by get_sb_block() instead of here */
1562                         /* *sb_block = match_int(&args[0]); */
1563                         break;
1564                 case Opt_err_panic:
1565                         clear_opt(sb, ERRORS_CONT);
1566                         clear_opt(sb, ERRORS_RO);
1567                         set_opt(sb, ERRORS_PANIC);
1568                         break;
1569                 case Opt_err_ro:
1570                         clear_opt(sb, ERRORS_CONT);
1571                         clear_opt(sb, ERRORS_PANIC);
1572                         set_opt(sb, ERRORS_RO);
1573                         break;
1574                 case Opt_err_cont:
1575                         clear_opt(sb, ERRORS_RO);
1576                         clear_opt(sb, ERRORS_PANIC);
1577                         set_opt(sb, ERRORS_CONT);
1578                         break;
1579                 case Opt_nouid32:
1580                         set_opt(sb, NO_UID32);
1581                         break;
1582                 case Opt_debug:
1583                         set_opt(sb, DEBUG);
1584                         break;
1585                 case Opt_oldalloc:
1586                         set_opt(sb, OLDALLOC);
1587                         break;
1588                 case Opt_orlov:
1589                         clear_opt(sb, OLDALLOC);
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 (test_opt(sb, DATA_FLAGS) != data_opt) {
1686                                         ext4_msg(sb, KERN_ERR,
1687                                                 "Cannot change data mode on remount");
1688                                         return 0;
1689                                 }
1690                         } else {
1691                                 clear_opt(sb, DATA_FLAGS);
1692                                 sbi->s_mount_opt |= data_opt;
1693                         }
1694                         break;
1695                 case Opt_data_err_abort:
1696                         set_opt(sb, DATA_ERR_ABORT);
1697                         break;
1698                 case Opt_data_err_ignore:
1699                         clear_opt(sb, DATA_ERR_ABORT);
1700                         break;
1701 #ifdef CONFIG_QUOTA
1702                 case Opt_usrjquota:
1703                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1704                                 return 0;
1705                         break;
1706                 case Opt_grpjquota:
1707                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1708                                 return 0;
1709                         break;
1710                 case Opt_offusrjquota:
1711                         if (!clear_qf_name(sb, USRQUOTA))
1712                                 return 0;
1713                         break;
1714                 case Opt_offgrpjquota:
1715                         if (!clear_qf_name(sb, GRPQUOTA))
1716                                 return 0;
1717                         break;
1718
1719                 case Opt_jqfmt_vfsold:
1720                         qfmt = QFMT_VFS_OLD;
1721                         goto set_qf_format;
1722                 case Opt_jqfmt_vfsv0:
1723                         qfmt = QFMT_VFS_V0;
1724                         goto set_qf_format;
1725                 case Opt_jqfmt_vfsv1:
1726                         qfmt = QFMT_VFS_V1;
1727 set_qf_format:
1728                         if (sb_any_quota_loaded(sb) &&
1729                             sbi->s_jquota_fmt != qfmt) {
1730                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1731                                         "journaled quota options when "
1732                                         "quota turned on");
1733                                 return 0;
1734                         }
1735                         sbi->s_jquota_fmt = qfmt;
1736                         break;
1737                 case Opt_quota:
1738                 case Opt_usrquota:
1739                         set_opt(sb, QUOTA);
1740                         set_opt(sb, USRQUOTA);
1741                         break;
1742                 case Opt_grpquota:
1743                         set_opt(sb, QUOTA);
1744                         set_opt(sb, GRPQUOTA);
1745                         break;
1746                 case Opt_noquota:
1747                         if (sb_any_quota_loaded(sb)) {
1748                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1749                                         "options when quota turned on");
1750                                 return 0;
1751                         }
1752                         clear_opt(sb, QUOTA);
1753                         clear_opt(sb, USRQUOTA);
1754                         clear_opt(sb, GRPQUOTA);
1755                         break;
1756 #else
1757                 case Opt_quota:
1758                 case Opt_usrquota:
1759                 case Opt_grpquota:
1760                         ext4_msg(sb, KERN_ERR,
1761                                 "quota options not supported");
1762                         break;
1763                 case Opt_usrjquota:
1764                 case Opt_grpjquota:
1765                 case Opt_offusrjquota:
1766                 case Opt_offgrpjquota:
1767                 case Opt_jqfmt_vfsold:
1768                 case Opt_jqfmt_vfsv0:
1769                 case Opt_jqfmt_vfsv1:
1770                         ext4_msg(sb, KERN_ERR,
1771                                 "journaled quota options not supported");
1772                         break;
1773                 case Opt_noquota:
1774                         break;
1775 #endif
1776                 case Opt_abort:
1777                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1778                         break;
1779                 case Opt_nobarrier:
1780                         clear_opt(sb, BARRIER);
1781                         break;
1782                 case Opt_barrier:
1783                         if (args[0].from) {
1784                                 if (match_int(&args[0], &option))
1785                                         return 0;
1786                         } else
1787                                 option = 1;     /* No argument, default to 1 */
1788                         if (option)
1789                                 set_opt(sb, BARRIER);
1790                         else
1791                                 clear_opt(sb, BARRIER);
1792                         break;
1793                 case Opt_ignore:
1794                         break;
1795                 case Opt_resize:
1796                         if (!is_remount) {
1797                                 ext4_msg(sb, KERN_ERR,
1798                                         "resize option only available "
1799                                         "for remount");
1800                                 return 0;
1801                         }
1802                         if (match_int(&args[0], &option) != 0)
1803                                 return 0;
1804                         *n_blocks_count = option;
1805                         break;
1806                 case Opt_nobh:
1807                         ext4_msg(sb, KERN_WARNING,
1808                                  "Ignoring deprecated nobh option");
1809                         break;
1810                 case Opt_bh:
1811                         ext4_msg(sb, KERN_WARNING,
1812                                  "Ignoring deprecated bh option");
1813                         break;
1814                 case Opt_i_version:
1815                         set_opt(sb, I_VERSION);
1816                         sb->s_flags |= MS_I_VERSION;
1817                         break;
1818                 case Opt_nodelalloc:
1819                         clear_opt(sb, DELALLOC);
1820                         clear_opt2(sb, EXPLICIT_DELALLOC);
1821                         break;
1822                 case Opt_mblk_io_submit:
1823                         set_opt(sb, MBLK_IO_SUBMIT);
1824                         break;
1825                 case Opt_nomblk_io_submit:
1826                         clear_opt(sb, MBLK_IO_SUBMIT);
1827                         break;
1828                 case Opt_stripe:
1829                         if (match_int(&args[0], &option))
1830                                 return 0;
1831                         if (option < 0)
1832                                 return 0;
1833                         sbi->s_stripe = option;
1834                         break;
1835                 case Opt_delalloc:
1836                         set_opt(sb, DELALLOC);
1837                         set_opt2(sb, EXPLICIT_DELALLOC);
1838                         break;
1839                 case Opt_block_validity:
1840                         set_opt(sb, BLOCK_VALIDITY);
1841                         break;
1842                 case Opt_noblock_validity:
1843                         clear_opt(sb, BLOCK_VALIDITY);
1844                         break;
1845                 case Opt_inode_readahead_blks:
1846                         if (match_int(&args[0], &option))
1847                                 return 0;
1848                         if (option < 0 || option > (1 << 30))
1849                                 return 0;
1850                         if (option && !is_power_of_2(option)) {
1851                                 ext4_msg(sb, KERN_ERR,
1852                                          "EXT4-fs: inode_readahead_blks"
1853                                          " must be a power of 2");
1854                                 return 0;
1855                         }
1856                         sbi->s_inode_readahead_blks = option;
1857                         break;
1858                 case Opt_journal_ioprio:
1859                         if (match_int(&args[0], &option))
1860                                 return 0;
1861                         if (option < 0 || option > 7)
1862                                 break;
1863                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1864                                                             option);
1865                         break;
1866                 case Opt_noauto_da_alloc:
1867                         set_opt(sb, NO_AUTO_DA_ALLOC);
1868                         break;
1869                 case Opt_auto_da_alloc:
1870                         if (args[0].from) {
1871                                 if (match_int(&args[0], &option))
1872                                         return 0;
1873                         } else
1874                                 option = 1;     /* No argument, default to 1 */
1875                         if (option)
1876                                 clear_opt(sb, NO_AUTO_DA_ALLOC);
1877                         else
1878                                 set_opt(sb,NO_AUTO_DA_ALLOC);
1879                         break;
1880                 case Opt_discard:
1881                         set_opt(sb, DISCARD);
1882                         break;
1883                 case Opt_nodiscard:
1884                         clear_opt(sb, DISCARD);
1885                         break;
1886                 case Opt_dioread_nolock:
1887                         set_opt(sb, DIOREAD_NOLOCK);
1888                         break;
1889                 case Opt_dioread_lock:
1890                         clear_opt(sb, DIOREAD_NOLOCK);
1891                         break;
1892                 case Opt_init_inode_table:
1893                         set_opt(sb, INIT_INODE_TABLE);
1894                         if (args[0].from) {
1895                                 if (match_int(&args[0], &option))
1896                                         return 0;
1897                         } else
1898                                 option = EXT4_DEF_LI_WAIT_MULT;
1899                         if (option < 0)
1900                                 return 0;
1901                         sbi->s_li_wait_mult = option;
1902                         break;
1903                 case Opt_noinit_inode_table:
1904                         clear_opt(sb, INIT_INODE_TABLE);
1905                         break;
1906                 default:
1907                         ext4_msg(sb, KERN_ERR,
1908                                "Unrecognized mount option \"%s\" "
1909                                "or missing value", p);
1910                         return 0;
1911                 }
1912         }
1913 #ifdef CONFIG_QUOTA
1914         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1915                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1916                         clear_opt(sb, USRQUOTA);
1917
1918                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1919                         clear_opt(sb, GRPQUOTA);
1920
1921                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1922                         ext4_msg(sb, KERN_ERR, "old and new quota "
1923                                         "format mixing");
1924                         return 0;
1925                 }
1926
1927                 if (!sbi->s_jquota_fmt) {
1928                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1929                                         "not specified");
1930                         return 0;
1931                 }
1932         } else {
1933                 if (sbi->s_jquota_fmt) {
1934                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1935                                         "specified with no journaling "
1936                                         "enabled");
1937                         return 0;
1938                 }
1939         }
1940 #endif
1941         return 1;
1942 }
1943
1944 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1945                             int read_only)
1946 {
1947         struct ext4_sb_info *sbi = EXT4_SB(sb);
1948         int res = 0;
1949
1950         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1951                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1952                          "forcing read-only mode");
1953                 res = MS_RDONLY;
1954         }
1955         if (read_only)
1956                 goto done;
1957         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1958                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1959                          "running e2fsck is recommended");
1960         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1961                 ext4_msg(sb, KERN_WARNING,
1962                          "warning: mounting fs with errors, "
1963                          "running e2fsck is recommended");
1964         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1965                  le16_to_cpu(es->s_mnt_count) >=
1966                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1967                 ext4_msg(sb, KERN_WARNING,
1968                          "warning: maximal mount count reached, "
1969                          "running e2fsck is recommended");
1970         else if (le32_to_cpu(es->s_checkinterval) &&
1971                 (le32_to_cpu(es->s_lastcheck) +
1972                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1973                 ext4_msg(sb, KERN_WARNING,
1974                          "warning: checktime reached, "
1975                          "running e2fsck is recommended");
1976         if (!sbi->s_journal)
1977                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1978         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1979                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1980         le16_add_cpu(&es->s_mnt_count, 1);
1981         es->s_mtime = cpu_to_le32(get_seconds());
1982         ext4_update_dynamic_rev(sb);
1983         if (sbi->s_journal)
1984                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1985
1986         ext4_commit_super(sb, 1);
1987 done:
1988         if (test_opt(sb, DEBUG))
1989                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1990                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1991                         sb->s_blocksize,
1992                         sbi->s_groups_count,
1993                         EXT4_BLOCKS_PER_GROUP(sb),
1994                         EXT4_INODES_PER_GROUP(sb),
1995                         sbi->s_mount_opt, sbi->s_mount_opt2);
1996
1997         cleancache_init_fs(sb);
1998         return res;
1999 }
2000
2001 static int ext4_fill_flex_info(struct super_block *sb)
2002 {
2003         struct ext4_sb_info *sbi = EXT4_SB(sb);
2004         struct ext4_group_desc *gdp = NULL;
2005         ext4_group_t flex_group_count;
2006         ext4_group_t flex_group;
2007         int groups_per_flex = 0;
2008         size_t size;
2009         int i;
2010
2011         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2012         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
2013
2014         if (groups_per_flex < 2) {
2015                 sbi->s_log_groups_per_flex = 0;
2016                 return 1;
2017         }
2018
2019         /* We allocate both existing and potentially added groups */
2020         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
2021                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
2022                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
2023         size = flex_group_count * sizeof(struct flex_groups);
2024         sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
2025         if (sbi->s_flex_groups == NULL) {
2026                 ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
2027                          flex_group_count);
2028                 goto failed;
2029         }
2030
2031         for (i = 0; i < sbi->s_groups_count; i++) {
2032                 gdp = ext4_get_group_desc(sb, i, NULL);
2033
2034                 flex_group = ext4_flex_group(sbi, i);
2035                 atomic_add(ext4_free_inodes_count(sb, gdp),
2036                            &sbi->s_flex_groups[flex_group].free_inodes);
2037                 atomic_add(ext4_free_blks_count(sb, gdp),
2038                            &sbi->s_flex_groups[flex_group].free_blocks);
2039                 atomic_add(ext4_used_dirs_count(sb, gdp),
2040                            &sbi->s_flex_groups[flex_group].used_dirs);
2041         }
2042
2043         return 1;
2044 failed:
2045         return 0;
2046 }
2047
2048 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2049                             struct ext4_group_desc *gdp)
2050 {
2051         __u16 crc = 0;
2052
2053         if (sbi->s_es->s_feature_ro_compat &
2054             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
2055                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
2056                 __le32 le_group = cpu_to_le32(block_group);
2057
2058                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2059                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2060                 crc = crc16(crc, (__u8 *)gdp, offset);
2061                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
2062                 /* for checksum of struct ext4_group_desc do the rest...*/
2063                 if ((sbi->s_es->s_feature_incompat &
2064                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2065                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
2066                         crc = crc16(crc, (__u8 *)gdp + offset,
2067                                     le16_to_cpu(sbi->s_es->s_desc_size) -
2068                                         offset);
2069         }
2070
2071         return cpu_to_le16(crc);
2072 }
2073
2074 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2075                                 struct ext4_group_desc *gdp)
2076 {
2077         if ((sbi->s_es->s_feature_ro_compat &
2078              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2079             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2080                 return 0;
2081
2082         return 1;
2083 }
2084
2085 /* Called at mount-time, super-block is locked */
2086 static int ext4_check_descriptors(struct super_block *sb,
2087                                   ext4_group_t *first_not_zeroed)
2088 {
2089         struct ext4_sb_info *sbi = EXT4_SB(sb);
2090         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2091         ext4_fsblk_t last_block;
2092         ext4_fsblk_t block_bitmap;
2093         ext4_fsblk_t inode_bitmap;
2094         ext4_fsblk_t inode_table;
2095         int flexbg_flag = 0;
2096         ext4_group_t i, grp = sbi->s_groups_count;
2097
2098         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2099                 flexbg_flag = 1;
2100
2101         ext4_debug("Checking group descriptors");
2102
2103         for (i = 0; i < sbi->s_groups_count; i++) {
2104                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2105
2106                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2107                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2108                 else
2109                         last_block = first_block +
2110                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2111
2112                 if ((grp == sbi->s_groups_count) &&
2113                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2114                         grp = i;
2115
2116                 block_bitmap = ext4_block_bitmap(sb, gdp);
2117                 if (block_bitmap < first_block || block_bitmap > last_block) {
2118                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2119                                "Block bitmap for group %u not in group "
2120                                "(block %llu)!", i, block_bitmap);
2121                         return 0;
2122                 }
2123                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2124                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2125                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2126                                "Inode bitmap for group %u not in group "
2127                                "(block %llu)!", i, inode_bitmap);
2128                         return 0;
2129                 }
2130                 inode_table = ext4_inode_table(sb, gdp);
2131                 if (inode_table < first_block ||
2132                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2133                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2134                                "Inode table for group %u not in group "
2135                                "(block %llu)!", i, inode_table);
2136                         return 0;
2137                 }
2138                 ext4_lock_group(sb, i);
2139                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2140                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2141                                  "Checksum for group %u failed (%u!=%u)",
2142                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2143                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2144                         if (!(sb->s_flags & MS_RDONLY)) {
2145                                 ext4_unlock_group(sb, i);
2146                                 return 0;
2147                         }
2148                 }
2149                 ext4_unlock_group(sb, i);
2150                 if (!flexbg_flag)
2151                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2152         }
2153         if (NULL != first_not_zeroed)
2154                 *first_not_zeroed = grp;
2155
2156         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
2157         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2158         return 1;
2159 }
2160
2161 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2162  * the superblock) which were deleted from all directories, but held open by
2163  * a process at the time of a crash.  We walk the list and try to delete these
2164  * inodes at recovery time (only with a read-write filesystem).
2165  *
2166  * In order to keep the orphan inode chain consistent during traversal (in
2167  * case of crash during recovery), we link each inode into the superblock
2168  * orphan list_head and handle it the same way as an inode deletion during
2169  * normal operation (which journals the operations for us).
2170  *
2171  * We only do an iget() and an iput() on each inode, which is very safe if we
2172  * accidentally point at an in-use or already deleted inode.  The worst that
2173  * can happen in this case is that we get a "bit already cleared" message from
2174  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2175  * e2fsck was run on this filesystem, and it must have already done the orphan
2176  * inode cleanup for us, so we can safely abort without any further action.
2177  */
2178 static void ext4_orphan_cleanup(struct super_block *sb,
2179                                 struct ext4_super_block *es)
2180 {
2181         unsigned int s_flags = sb->s_flags;
2182         int nr_orphans = 0, nr_truncates = 0;
2183 #ifdef CONFIG_QUOTA
2184         int i;
2185 #endif
2186         if (!es->s_last_orphan) {
2187                 jbd_debug(4, "no orphan inodes to clean up\n");
2188                 return;
2189         }
2190
2191         if (bdev_read_only(sb->s_bdev)) {
2192                 ext4_msg(sb, KERN_ERR, "write access "
2193                         "unavailable, skipping orphan cleanup");
2194                 return;
2195         }
2196
2197         /* Check if feature set would not allow a r/w mount */
2198         if (!ext4_feature_set_ok(sb, 0)) {
2199                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2200                          "unknown ROCOMPAT features");
2201                 return;
2202         }
2203
2204         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2205                 if (es->s_last_orphan)
2206                         jbd_debug(1, "Errors on filesystem, "
2207                                   "clearing orphan list.\n");
2208                 es->s_last_orphan = 0;
2209                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2210                 return;
2211         }
2212
2213         if (s_flags & MS_RDONLY) {
2214                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2215                 sb->s_flags &= ~MS_RDONLY;
2216         }
2217 #ifdef CONFIG_QUOTA
2218         /* Needed for iput() to work correctly and not trash data */
2219         sb->s_flags |= MS_ACTIVE;
2220         /* Turn on quotas so that they are updated correctly */
2221         for (i = 0; i < MAXQUOTAS; i++) {
2222                 if (EXT4_SB(sb)->s_qf_names[i]) {
2223                         int ret = ext4_quota_on_mount(sb, i);
2224                         if (ret < 0)
2225                                 ext4_msg(sb, KERN_ERR,
2226                                         "Cannot turn on journaled "
2227                                         "quota: error %d", ret);
2228                 }
2229         }
2230 #endif
2231
2232         while (es->s_last_orphan) {
2233                 struct inode *inode;
2234
2235                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2236                 if (IS_ERR(inode)) {
2237                         es->s_last_orphan = 0;
2238                         break;
2239                 }
2240
2241                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2242                 dquot_initialize(inode);
2243                 if (inode->i_nlink) {
2244                         ext4_msg(sb, KERN_DEBUG,
2245                                 "%s: truncating inode %lu to %lld bytes",
2246                                 __func__, inode->i_ino, inode->i_size);
2247                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2248                                   inode->i_ino, inode->i_size);
2249                         ext4_truncate(inode);
2250                         nr_truncates++;
2251                 } else {
2252                         ext4_msg(sb, KERN_DEBUG,
2253                                 "%s: deleting unreferenced inode %lu",
2254                                 __func__, inode->i_ino);
2255                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2256                                   inode->i_ino);
2257                         nr_orphans++;
2258                 }
2259                 iput(inode);  /* The delete magic happens here! */
2260         }
2261
2262 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2263
2264         if (nr_orphans)
2265                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2266                        PLURAL(nr_orphans));
2267         if (nr_truncates)
2268                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2269                        PLURAL(nr_truncates));
2270 #ifdef CONFIG_QUOTA
2271         /* Turn quotas off */
2272         for (i = 0; i < MAXQUOTAS; i++) {
2273                 if (sb_dqopt(sb)->files[i])
2274                         dquot_quota_off(sb, i);
2275         }
2276 #endif
2277         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2278 }
2279
2280 /*
2281  * Maximal extent format file size.
2282  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2283  * extent format containers, within a sector_t, and within i_blocks
2284  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2285  * so that won't be a limiting factor.
2286  *
2287  * However there is other limiting factor. We do store extents in the form
2288  * of starting block and length, hence the resulting length of the extent
2289  * covering maximum file size must fit into on-disk format containers as
2290  * well. Given that length is always by 1 unit bigger than max unit (because
2291  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2292  *
2293  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2294  */
2295 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2296 {
2297         loff_t res;
2298         loff_t upper_limit = MAX_LFS_FILESIZE;
2299
2300         /* small i_blocks in vfs inode? */
2301         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2302                 /*
2303                  * CONFIG_LBDAF is not enabled implies the inode
2304                  * i_block represent total blocks in 512 bytes
2305                  * 32 == size of vfs inode i_blocks * 8
2306                  */
2307                 upper_limit = (1LL << 32) - 1;
2308
2309                 /* total blocks in file system block size */
2310                 upper_limit >>= (blkbits - 9);
2311                 upper_limit <<= blkbits;
2312         }
2313
2314         /*
2315          * 32-bit extent-start container, ee_block. We lower the maxbytes
2316          * by one fs block, so ee_len can cover the extent of maximum file
2317          * size
2318          */
2319         res = (1LL << 32) - 1;
2320         res <<= blkbits;
2321
2322         /* Sanity check against vm- & vfs- imposed limits */
2323         if (res > upper_limit)
2324                 res = upper_limit;
2325
2326         return res;
2327 }
2328
2329 /*
2330  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2331  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2332  * We need to be 1 filesystem block less than the 2^48 sector limit.
2333  */
2334 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2335 {
2336         loff_t res = EXT4_NDIR_BLOCKS;
2337         int meta_blocks;
2338         loff_t upper_limit;
2339         /* This is calculated to be the largest file size for a dense, block
2340          * mapped file such that the file's total number of 512-byte sectors,
2341          * including data and all indirect blocks, does not exceed (2^48 - 1).
2342          *
2343          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2344          * number of 512-byte sectors of the file.
2345          */
2346
2347         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2348                 /*
2349                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2350                  * the inode i_block field represents total file blocks in
2351                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2352                  */
2353                 upper_limit = (1LL << 32) - 1;
2354
2355                 /* total blocks in file system block size */
2356                 upper_limit >>= (bits - 9);
2357
2358         } else {
2359                 /*
2360                  * We use 48 bit ext4_inode i_blocks
2361                  * With EXT4_HUGE_FILE_FL set the i_blocks
2362                  * represent total number of blocks in
2363                  * file system block size
2364                  */
2365                 upper_limit = (1LL << 48) - 1;
2366
2367         }
2368
2369         /* indirect blocks */
2370         meta_blocks = 1;
2371         /* double indirect blocks */
2372         meta_blocks += 1 + (1LL << (bits-2));
2373         /* tripple indirect blocks */
2374         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2375
2376         upper_limit -= meta_blocks;
2377         upper_limit <<= bits;
2378
2379         res += 1LL << (bits-2);
2380         res += 1LL << (2*(bits-2));
2381         res += 1LL << (3*(bits-2));
2382         res <<= bits;
2383         if (res > upper_limit)
2384                 res = upper_limit;
2385
2386         if (res > MAX_LFS_FILESIZE)
2387                 res = MAX_LFS_FILESIZE;
2388
2389         return res;
2390 }
2391
2392 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2393                                    ext4_fsblk_t logical_sb_block, int nr)
2394 {
2395         struct ext4_sb_info *sbi = EXT4_SB(sb);
2396         ext4_group_t bg, first_meta_bg;
2397         int has_super = 0;
2398
2399         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2400
2401         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2402             nr < first_meta_bg)
2403                 return logical_sb_block + nr + 1;
2404         bg = sbi->s_desc_per_block * nr;
2405         if (ext4_bg_has_super(sb, bg))
2406                 has_super = 1;
2407
2408         return (has_super + ext4_group_first_block_no(sb, bg));
2409 }
2410
2411 /**
2412  * ext4_get_stripe_size: Get the stripe size.
2413  * @sbi: In memory super block info
2414  *
2415  * If we have specified it via mount option, then
2416  * use the mount option value. If the value specified at mount time is
2417  * greater than the blocks per group use the super block value.
2418  * If the super block value is greater than blocks per group return 0.
2419  * Allocator needs it be less than blocks per group.
2420  *
2421  */
2422 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2423 {
2424         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2425         unsigned long stripe_width =
2426                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2427         int ret;
2428
2429         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2430                 ret = sbi->s_stripe;
2431         else if (stripe_width <= sbi->s_blocks_per_group)
2432                 ret = stripe_width;
2433         else if (stride <= sbi->s_blocks_per_group)
2434                 ret = stride;
2435         else
2436                 ret = 0;
2437
2438         /*
2439          * If the stripe width is 1, this makes no sense and
2440          * we set it to 0 to turn off stripe handling code.
2441          */
2442         if (ret <= 1)
2443                 ret = 0;
2444
2445         return ret;
2446 }
2447
2448 /* sysfs supprt */
2449
2450 struct ext4_attr {
2451         struct attribute attr;
2452         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2453         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2454                          const char *, size_t);
2455         int offset;
2456 };
2457
2458 static int parse_strtoul(const char *buf,
2459                 unsigned long max, unsigned long *value)
2460 {
2461         char *endp;
2462
2463         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2464         endp = skip_spaces(endp);
2465         if (*endp || *value > max)
2466                 return -EINVAL;
2467
2468         return 0;
2469 }
2470
2471 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2472                                               struct ext4_sb_info *sbi,
2473                                               char *buf)
2474 {
2475         return snprintf(buf, PAGE_SIZE, "%llu\n",
2476                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2477 }
2478
2479 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2480                                          struct ext4_sb_info *sbi, char *buf)
2481 {
2482         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2483
2484         if (!sb->s_bdev->bd_part)
2485                 return snprintf(buf, PAGE_SIZE, "0\n");
2486         return snprintf(buf, PAGE_SIZE, "%lu\n",
2487                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2488                          sbi->s_sectors_written_start) >> 1);
2489 }
2490
2491 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2492                                           struct ext4_sb_info *sbi, char *buf)
2493 {
2494         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2495
2496         if (!sb->s_bdev->bd_part)
2497                 return snprintf(buf, PAGE_SIZE, "0\n");
2498         return snprintf(buf, PAGE_SIZE, "%llu\n",
2499                         (unsigned long long)(sbi->s_kbytes_written +
2500                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2501                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2502 }
2503
2504 static ssize_t extent_cache_hits_show(struct ext4_attr *a,
2505                                       struct ext4_sb_info *sbi, char *buf)
2506 {
2507         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
2508 }
2509
2510 static ssize_t extent_cache_misses_show(struct ext4_attr *a,
2511                                         struct ext4_sb_info *sbi, char *buf)
2512 {
2513         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
2514 }
2515
2516 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2517                                           struct ext4_sb_info *sbi,
2518                                           const char *buf, size_t count)
2519 {
2520         unsigned long t;
2521
2522         if (parse_strtoul(buf, 0x40000000, &t))
2523                 return -EINVAL;
2524
2525         if (t && !is_power_of_2(t))
2526                 return -EINVAL;
2527
2528         sbi->s_inode_readahead_blks = t;
2529         return count;
2530 }
2531
2532 static ssize_t sbi_ui_show(struct ext4_attr *a,
2533                            struct ext4_sb_info *sbi, char *buf)
2534 {
2535         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2536
2537         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2538 }
2539
2540 static ssize_t sbi_ui_store(struct ext4_attr *a,
2541                             struct ext4_sb_info *sbi,
2542                             const char *buf, size_t count)
2543 {
2544         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2545         unsigned long t;
2546
2547         if (parse_strtoul(buf, 0xffffffff, &t))
2548                 return -EINVAL;
2549         *ui = t;
2550         return count;
2551 }
2552
2553 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2554 static struct ext4_attr ext4_attr_##_name = {                   \
2555         .attr = {.name = __stringify(_name), .mode = _mode },   \
2556         .show   = _show,                                        \
2557         .store  = _store,                                       \
2558         .offset = offsetof(struct ext4_sb_info, _elname),       \
2559 }
2560 #define EXT4_ATTR(name, mode, show, store) \
2561 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2562
2563 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2564 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2565 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2566 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2567         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2568 #define ATTR_LIST(name) &ext4_attr_##name.attr
2569
2570 EXT4_RO_ATTR(delayed_allocation_blocks);
2571 EXT4_RO_ATTR(session_write_kbytes);
2572 EXT4_RO_ATTR(lifetime_write_kbytes);
2573 EXT4_RO_ATTR(extent_cache_hits);
2574 EXT4_RO_ATTR(extent_cache_misses);
2575 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2576                  inode_readahead_blks_store, s_inode_readahead_blks);
2577 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2578 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2579 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2580 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2581 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2582 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2583 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2584 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2585
2586 static struct attribute *ext4_attrs[] = {
2587         ATTR_LIST(delayed_allocation_blocks),
2588         ATTR_LIST(session_write_kbytes),
2589         ATTR_LIST(lifetime_write_kbytes),
2590         ATTR_LIST(extent_cache_hits),
2591         ATTR_LIST(extent_cache_misses),
2592         ATTR_LIST(inode_readahead_blks),
2593         ATTR_LIST(inode_goal),
2594         ATTR_LIST(mb_stats),
2595         ATTR_LIST(mb_max_to_scan),
2596         ATTR_LIST(mb_min_to_scan),
2597         ATTR_LIST(mb_order2_req),
2598         ATTR_LIST(mb_stream_req),
2599         ATTR_LIST(mb_group_prealloc),
2600         ATTR_LIST(max_writeback_mb_bump),
2601         NULL,
2602 };
2603
2604 /* Features this copy of ext4 supports */
2605 EXT4_INFO_ATTR(lazy_itable_init);
2606 EXT4_INFO_ATTR(batched_discard);
2607
2608 static struct attribute *ext4_feat_attrs[] = {
2609         ATTR_LIST(lazy_itable_init),
2610         ATTR_LIST(batched_discard),
2611         NULL,
2612 };
2613
2614 static ssize_t ext4_attr_show(struct kobject *kobj,
2615                               struct attribute *attr, char *buf)
2616 {
2617         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2618                                                 s_kobj);
2619         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2620
2621         return a->show ? a->show(a, sbi, buf) : 0;
2622 }
2623
2624 static ssize_t ext4_attr_store(struct kobject *kobj,
2625                                struct attribute *attr,
2626                                const char *buf, size_t len)
2627 {
2628         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2629                                                 s_kobj);
2630         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2631
2632         return a->store ? a->store(a, sbi, buf, len) : 0;
2633 }
2634
2635 static void ext4_sb_release(struct kobject *kobj)
2636 {
2637         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2638                                                 s_kobj);
2639         complete(&sbi->s_kobj_unregister);
2640 }
2641
2642 static const struct sysfs_ops ext4_attr_ops = {
2643         .show   = ext4_attr_show,
2644         .store  = ext4_attr_store,
2645 };
2646
2647 static struct kobj_type ext4_ktype = {
2648         .default_attrs  = ext4_attrs,
2649         .sysfs_ops      = &ext4_attr_ops,
2650         .release        = ext4_sb_release,
2651 };
2652
2653 static void ext4_feat_release(struct kobject *kobj)
2654 {
2655         complete(&ext4_feat->f_kobj_unregister);
2656 }
2657
2658 static struct kobj_type ext4_feat_ktype = {
2659         .default_attrs  = ext4_feat_attrs,
2660         .sysfs_ops      = &ext4_attr_ops,
2661         .release        = ext4_feat_release,
2662 };
2663
2664 /*
2665  * Check whether this filesystem can be mounted based on
2666  * the features present and the RDONLY/RDWR mount requested.
2667  * Returns 1 if this filesystem can be mounted as requested,
2668  * 0 if it cannot be.
2669  */
2670 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2671 {
2672         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2673                 ext4_msg(sb, KERN_ERR,
2674                         "Couldn't mount because of "
2675                         "unsupported optional features (%x)",
2676                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2677                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2678                 return 0;
2679         }
2680
2681         if (readonly)
2682                 return 1;
2683
2684         /* Check that feature set is OK for a read-write mount */
2685         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2686                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2687                          "unsupported optional features (%x)",
2688                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2689                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2690                 return 0;
2691         }
2692         /*
2693          * Large file size enabled file system can only be mounted
2694          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2695          */
2696         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2697                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2698                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2699                                  "cannot be mounted RDWR without "
2700                                  "CONFIG_LBDAF");
2701                         return 0;
2702                 }
2703         }
2704         return 1;
2705 }
2706
2707 /*
2708  * This function is called once a day if we have errors logged
2709  * on the file system
2710  */
2711 static void print_daily_error_info(unsigned long arg)
2712 {
2713         struct super_block *sb = (struct super_block *) arg;
2714         struct ext4_sb_info *sbi;
2715         struct ext4_super_block *es;
2716
2717         sbi = EXT4_SB(sb);
2718         es = sbi->s_es;
2719
2720         if (es->s_error_count)
2721                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2722                          le32_to_cpu(es->s_error_count));
2723         if (es->s_first_error_time) {
2724                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2725                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2726                        (int) sizeof(es->s_first_error_func),
2727                        es->s_first_error_func,
2728                        le32_to_cpu(es->s_first_error_line));
2729                 if (es->s_first_error_ino)
2730                         printk(": inode %u",
2731                                le32_to_cpu(es->s_first_error_ino));
2732                 if (es->s_first_error_block)
2733                         printk(": block %llu", (unsigned long long)
2734                                le64_to_cpu(es->s_first_error_block));
2735                 printk("\n");
2736         }
2737         if (es->s_last_error_time) {
2738                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2739                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2740                        (int) sizeof(es->s_last_error_func),
2741                        es->s_last_error_func,
2742                        le32_to_cpu(es->s_last_error_line));
2743                 if (es->s_last_error_ino)
2744                         printk(": inode %u",
2745                                le32_to_cpu(es->s_last_error_ino));
2746                 if (es->s_last_error_block)
2747                         printk(": block %llu", (unsigned long long)
2748                                le64_to_cpu(es->s_last_error_block));
2749                 printk("\n");
2750         }
2751         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2752 }
2753
2754 /* Find next suitable group and run ext4_init_inode_table */
2755 static int ext4_run_li_request(struct ext4_li_request *elr)
2756 {
2757         struct ext4_group_desc *gdp = NULL;
2758         ext4_group_t group, ngroups;
2759         struct super_block *sb;
2760         unsigned long timeout = 0;
2761         int ret = 0;
2762
2763         sb = elr->lr_super;
2764         ngroups = EXT4_SB(sb)->s_groups_count;
2765
2766         for (group = elr->lr_next_group; group < ngroups; group++) {
2767                 gdp = ext4_get_group_desc(sb, group, NULL);
2768                 if (!gdp) {
2769                         ret = 1;
2770                         break;
2771                 }
2772
2773                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2774                         break;
2775         }
2776
2777         if (group == ngroups)
2778                 ret = 1;
2779
2780         if (!ret) {
2781                 timeout = jiffies;
2782                 ret = ext4_init_inode_table(sb, group,
2783                                             elr->lr_timeout ? 0 : 1);
2784                 if (elr->lr_timeout == 0) {
2785                         timeout = (jiffies - timeout) *
2786                                   elr->lr_sbi->s_li_wait_mult;
2787                         elr->lr_timeout = timeout;
2788                 }
2789                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2790                 elr->lr_next_group = group + 1;
2791         }
2792
2793         return ret;
2794 }
2795
2796 /*
2797  * Remove lr_request from the list_request and free the
2798  * request structure. Should be called with li_list_mtx held
2799  */
2800 static void ext4_remove_li_request(struct ext4_li_request *elr)
2801 {
2802         struct ext4_sb_info *sbi;
2803
2804         if (!elr)
2805                 return;
2806
2807         sbi = elr->lr_sbi;
2808
2809         list_del(&elr->lr_request);
2810         sbi->s_li_request = NULL;
2811         kfree(elr);
2812 }
2813
2814 static void ext4_unregister_li_request(struct super_block *sb)
2815 {
2816         mutex_lock(&ext4_li_mtx);
2817         if (!ext4_li_info) {
2818                 mutex_unlock(&ext4_li_mtx);
2819                 return;
2820         }
2821
2822         mutex_lock(&ext4_li_info->li_list_mtx);
2823         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2824         mutex_unlock(&ext4_li_info->li_list_mtx);
2825         mutex_unlock(&ext4_li_mtx);
2826 }
2827
2828 static struct task_struct *ext4_lazyinit_task;
2829
2830 /*
2831  * This is the function where ext4lazyinit thread lives. It walks
2832  * through the request list searching for next scheduled filesystem.
2833  * When such a fs is found, run the lazy initialization request
2834  * (ext4_rn_li_request) and keep track of the time spend in this
2835  * function. Based on that time we compute next schedule time of
2836  * the request. When walking through the list is complete, compute
2837  * next waking time and put itself into sleep.
2838  */
2839 static int ext4_lazyinit_thread(void *arg)
2840 {
2841         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2842         struct list_head *pos, *n;
2843         struct ext4_li_request *elr;
2844         unsigned long next_wakeup, cur;
2845
2846         BUG_ON(NULL == eli);
2847
2848 cont_thread:
2849         while (true) {
2850                 next_wakeup = MAX_JIFFY_OFFSET;
2851
2852                 mutex_lock(&eli->li_list_mtx);
2853                 if (list_empty(&eli->li_request_list)) {
2854                         mutex_unlock(&eli->li_list_mtx);
2855                         goto exit_thread;
2856                 }
2857
2858                 list_for_each_safe(pos, n, &eli->li_request_list) {
2859                         elr = list_entry(pos, struct ext4_li_request,
2860                                          lr_request);
2861
2862                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2863                                 if (ext4_run_li_request(elr) != 0) {
2864                                         /* error, remove the lazy_init job */
2865                                         ext4_remove_li_request(elr);
2866                                         continue;
2867                                 }
2868                         }
2869
2870                         if (time_before(elr->lr_next_sched, next_wakeup))
2871                                 next_wakeup = elr->lr_next_sched;
2872                 }
2873                 mutex_unlock(&eli->li_list_mtx);
2874
2875                 if (freezing(current))
2876                         refrigerator();
2877
2878                 cur = jiffies;
2879                 if ((time_after_eq(cur, next_wakeup)) ||
2880                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2881                         cond_resched();
2882                         continue;
2883                 }
2884
2885                 schedule_timeout_interruptible(next_wakeup - cur);
2886
2887                 if (kthread_should_stop()) {
2888                         ext4_clear_request_list();
2889                         goto exit_thread;
2890                 }
2891         }
2892
2893 exit_thread:
2894         /*
2895          * It looks like the request list is empty, but we need
2896          * to check it under the li_list_mtx lock, to prevent any
2897          * additions into it, and of course we should lock ext4_li_mtx
2898          * to atomically free the list and ext4_li_info, because at
2899          * this point another ext4 filesystem could be registering
2900          * new one.
2901          */
2902         mutex_lock(&ext4_li_mtx);
2903         mutex_lock(&eli->li_list_mtx);
2904         if (!list_empty(&eli->li_request_list)) {
2905                 mutex_unlock(&eli->li_list_mtx);
2906                 mutex_unlock(&ext4_li_mtx);
2907                 goto cont_thread;
2908         }
2909         mutex_unlock(&eli->li_list_mtx);
2910         kfree(ext4_li_info);
2911         ext4_li_info = NULL;
2912         mutex_unlock(&ext4_li_mtx);
2913
2914         return 0;
2915 }
2916
2917 static void ext4_clear_request_list(void)
2918 {
2919         struct list_head *pos, *n;
2920         struct ext4_li_request *elr;
2921
2922         mutex_lock(&ext4_li_info->li_list_mtx);
2923         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2924                 elr = list_entry(pos, struct ext4_li_request,
2925                                  lr_request);
2926                 ext4_remove_li_request(elr);
2927         }
2928         mutex_unlock(&ext4_li_info->li_list_mtx);
2929 }
2930
2931 static int ext4_run_lazyinit_thread(void)
2932 {
2933         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2934                                          ext4_li_info, "ext4lazyinit");
2935         if (IS_ERR(ext4_lazyinit_task)) {
2936                 int err = PTR_ERR(ext4_lazyinit_task);
2937                 ext4_clear_request_list();
2938                 kfree(ext4_li_info);
2939                 ext4_li_info = NULL;
2940                 printk(KERN_CRIT "EXT4: error %d creating inode table "
2941                                  "initialization thread\n",
2942                                  err);
2943                 return err;
2944         }
2945         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2946         return 0;
2947 }
2948
2949 /*
2950  * Check whether it make sense to run itable init. thread or not.
2951  * If there is at least one uninitialized inode table, return
2952  * corresponding group number, else the loop goes through all
2953  * groups and return total number of groups.
2954  */
2955 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2956 {
2957         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2958         struct ext4_group_desc *gdp = NULL;
2959
2960         for (group = 0; group < ngroups; group++) {
2961                 gdp = ext4_get_group_desc(sb, group, NULL);
2962                 if (!gdp)
2963                         continue;
2964
2965                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2966                         break;
2967         }
2968
2969         return group;
2970 }
2971
2972 static int ext4_li_info_new(void)
2973 {
2974         struct ext4_lazy_init *eli = NULL;
2975
2976         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2977         if (!eli)
2978                 return -ENOMEM;
2979
2980         INIT_LIST_HEAD(&eli->li_request_list);
2981         mutex_init(&eli->li_list_mtx);
2982
2983         eli->li_state |= EXT4_LAZYINIT_QUIT;
2984
2985         ext4_li_info = eli;
2986
2987         return 0;
2988 }
2989
2990 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2991                                             ext4_group_t start)
2992 {
2993         struct ext4_sb_info *sbi = EXT4_SB(sb);
2994         struct ext4_li_request *elr;
2995         unsigned long rnd;
2996
2997         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2998         if (!elr)
2999                 return NULL;
3000
3001         elr->lr_super = sb;
3002         elr->lr_sbi = sbi;
3003         elr->lr_next_group = start;
3004
3005         /*
3006          * Randomize first schedule time of the request to
3007          * spread the inode table initialization requests
3008          * better.
3009          */
3010         get_random_bytes(&rnd, sizeof(rnd));
3011         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3012                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3013
3014         return elr;
3015 }
3016
3017 static int ext4_register_li_request(struct super_block *sb,
3018                                     ext4_group_t first_not_zeroed)
3019 {
3020         struct ext4_sb_info *sbi = EXT4_SB(sb);
3021         struct ext4_li_request *elr;
3022         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3023         int ret = 0;
3024
3025         if (sbi->s_li_request != NULL) {
3026                 /*
3027                  * Reset timeout so it can be computed again, because
3028                  * s_li_wait_mult might have changed.
3029                  */
3030                 sbi->s_li_request->lr_timeout = 0;
3031                 return 0;
3032         }
3033
3034         if (first_not_zeroed == ngroups ||
3035             (sb->s_flags & MS_RDONLY) ||
3036             !test_opt(sb, INIT_INODE_TABLE))
3037                 return 0;
3038
3039         elr = ext4_li_request_new(sb, first_not_zeroed);
3040         if (!elr)
3041                 return -ENOMEM;
3042
3043         mutex_lock(&ext4_li_mtx);
3044
3045         if (NULL == ext4_li_info) {
3046                 ret = ext4_li_info_new();
3047                 if (ret)
3048                         goto out;
3049         }
3050
3051         mutex_lock(&ext4_li_info->li_list_mtx);
3052         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3053         mutex_unlock(&ext4_li_info->li_list_mtx);
3054
3055         sbi->s_li_request = elr;
3056         /*
3057          * set elr to NULL here since it has been inserted to
3058          * the request_list and the removal and free of it is
3059          * handled by ext4_clear_request_list from now on.
3060          */
3061         elr = NULL;
3062
3063         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3064                 ret = ext4_run_lazyinit_thread();
3065                 if (ret)
3066                         goto out;
3067         }
3068 out:
3069         mutex_unlock(&ext4_li_mtx);
3070         if (ret)
3071                 kfree(elr);
3072         return ret;
3073 }
3074
3075 /*
3076  * We do not need to lock anything since this is called on
3077  * module unload.
3078  */
3079 static void ext4_destroy_lazyinit_thread(void)
3080 {
3081         /*
3082          * If thread exited earlier
3083          * there's nothing to be done.
3084          */
3085         if (!ext4_li_info || !ext4_lazyinit_task)
3086                 return;
3087
3088         kthread_stop(ext4_lazyinit_task);
3089 }
3090
3091 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3092                                 __releases(kernel_lock)
3093                                 __acquires(kernel_lock)
3094 {
3095         char *orig_data = kstrdup(data, GFP_KERNEL);
3096         struct buffer_head *bh;
3097         struct ext4_super_block *es = NULL;
3098         struct ext4_sb_info *sbi;
3099         ext4_fsblk_t block;
3100         ext4_fsblk_t sb_block = get_sb_block(&data);
3101         ext4_fsblk_t logical_sb_block;
3102         unsigned long offset = 0;
3103         unsigned long journal_devnum = 0;
3104         unsigned long def_mount_opts;
3105         struct inode *root;
3106         char *cp;
3107         const char *descr;
3108         int ret = -ENOMEM;
3109         int blocksize, clustersize;
3110         unsigned int db_count;
3111         unsigned int i;
3112         int needs_recovery, has_huge_files, has_bigalloc;
3113         __u64 blocks_count;
3114         int err;
3115         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3116         ext4_group_t first_not_zeroed;
3117
3118         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3119         if (!sbi)
3120                 goto out_free_orig;
3121
3122         sbi->s_blockgroup_lock =
3123                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3124         if (!sbi->s_blockgroup_lock) {
3125                 kfree(sbi);
3126                 goto out_free_orig;
3127         }
3128         sb->s_fs_info = sbi;
3129         sbi->s_mount_opt = 0;
3130         sbi->s_resuid = EXT4_DEF_RESUID;
3131         sbi->s_resgid = EXT4_DEF_RESGID;
3132         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3133         sbi->s_sb_block = sb_block;
3134         if (sb->s_bdev->bd_part)
3135                 sbi->s_sectors_written_start =
3136                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3137
3138         /* Cleanup superblock name */
3139         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3140                 *cp = '!';
3141
3142         ret = -EINVAL;
3143         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3144         if (!blocksize) {
3145                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3146                 goto out_fail;
3147         }
3148
3149         /*
3150          * The ext4 superblock will not be buffer aligned for other than 1kB
3151          * block sizes.  We need to calculate the offset from buffer start.
3152          */
3153         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3154                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3155                 offset = do_div(logical_sb_block, blocksize);
3156         } else {
3157                 logical_sb_block = sb_block;
3158         }
3159
3160         if (!(bh = sb_bread(sb, logical_sb_block))) {
3161                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3162                 goto out_fail;
3163         }
3164         /*
3165          * Note: s_es must be initialized as soon as possible because
3166          *       some ext4 macro-instructions depend on its value
3167          */
3168         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3169         sbi->s_es = es;
3170         sb->s_magic = le16_to_cpu(es->s_magic);
3171         if (sb->s_magic != EXT4_SUPER_MAGIC)
3172                 goto cantfind_ext4;
3173         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3174
3175         /* Set defaults before we parse the mount options */
3176         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3177         set_opt(sb, INIT_INODE_TABLE);
3178         if (def_mount_opts & EXT4_DEFM_DEBUG)
3179                 set_opt(sb, DEBUG);
3180         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3181                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3182                         "2.6.38");
3183                 set_opt(sb, GRPID);
3184         }
3185         if (def_mount_opts & EXT4_DEFM_UID16)
3186                 set_opt(sb, NO_UID32);
3187         /* xattr user namespace & acls are now defaulted on */
3188 #ifdef CONFIG_EXT4_FS_XATTR
3189         set_opt(sb, XATTR_USER);
3190 #endif
3191 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3192         set_opt(sb, POSIX_ACL);
3193 #endif
3194         set_opt(sb, MBLK_IO_SUBMIT);
3195         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3196                 set_opt(sb, JOURNAL_DATA);
3197         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3198                 set_opt(sb, ORDERED_DATA);
3199         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3200                 set_opt(sb, WRITEBACK_DATA);
3201
3202         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3203                 set_opt(sb, ERRORS_PANIC);
3204         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3205                 set_opt(sb, ERRORS_CONT);
3206         else
3207                 set_opt(sb, ERRORS_RO);
3208         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3209                 set_opt(sb, BLOCK_VALIDITY);
3210         if (def_mount_opts & EXT4_DEFM_DISCARD)
3211                 set_opt(sb, DISCARD);
3212
3213         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3214         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3215         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3216         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3217         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3218
3219         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3220                 set_opt(sb, BARRIER);
3221
3222         /*
3223          * enable delayed allocation by default
3224          * Use -o nodelalloc to turn it off
3225          */
3226         if (!IS_EXT3_SB(sb) &&
3227             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3228                 set_opt(sb, DELALLOC);
3229
3230         /*
3231          * set default s_li_wait_mult for lazyinit, for the case there is
3232          * no mount option specified.
3233          */
3234         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3235
3236         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3237                            &journal_devnum, &journal_ioprio, NULL, 0)) {
3238                 ext4_msg(sb, KERN_WARNING,
3239                          "failed to parse options in superblock: %s",
3240                          sbi->s_es->s_mount_opts);
3241         }
3242         if (!parse_options((char *) data, sb, &journal_devnum,
3243                            &journal_ioprio, NULL, 0))
3244                 goto failed_mount;
3245
3246         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3247                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3248                             "with data=journal disables delayed "
3249                             "allocation and O_DIRECT support!\n");
3250                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3251                         ext4_msg(sb, KERN_ERR, "can't mount with "
3252                                  "both data=journal and delalloc");
3253                         goto failed_mount;
3254                 }
3255                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3256                         ext4_msg(sb, KERN_ERR, "can't mount with "
3257                                  "both data=journal and delalloc");
3258                         goto failed_mount;
3259                 }
3260                 if (test_opt(sb, DELALLOC))
3261                         clear_opt(sb, DELALLOC);
3262         }
3263
3264         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3265         if (test_opt(sb, DIOREAD_NOLOCK)) {
3266                 if (blocksize < PAGE_SIZE) {
3267                         ext4_msg(sb, KERN_ERR, "can't mount with "
3268                                  "dioread_nolock if block size != PAGE_SIZE");
3269                         goto failed_mount;
3270                 }
3271         }
3272
3273         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3274                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3275
3276         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3277             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3278              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3279              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3280                 ext4_msg(sb, KERN_WARNING,
3281                        "feature flags set on rev 0 fs, "
3282                        "running e2fsck is recommended");
3283
3284         if (IS_EXT2_SB(sb)) {
3285                 if (ext2_feature_set_ok(sb))
3286                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3287                                  "using the ext4 subsystem");
3288                 else {
3289                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3290                                  "to feature incompatibilities");
3291                         goto failed_mount;
3292                 }
3293         }
3294
3295         if (IS_EXT3_SB(sb)) {
3296                 if (ext3_feature_set_ok(sb))
3297                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3298                                  "using the ext4 subsystem");
3299                 else {
3300                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3301                                  "to feature incompatibilities");
3302                         goto failed_mount;
3303                 }
3304         }
3305
3306         /*
3307          * Check feature flags regardless of the revision level, since we
3308          * previously didn't change the revision level when setting the flags,
3309          * so there is a chance incompat flags are set on a rev 0 filesystem.
3310          */
3311         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3312                 goto failed_mount;
3313
3314         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3315             blocksize > EXT4_MAX_BLOCK_SIZE) {
3316                 ext4_msg(sb, KERN_ERR,
3317                        "Unsupported filesystem blocksize %d", blocksize);
3318                 goto failed_mount;
3319         }
3320
3321         if (sb->s_blocksize != blocksize) {
3322                 /* Validate the filesystem blocksize */
3323                 if (!sb_set_blocksize(sb, blocksize)) {
3324                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3325                                         blocksize);
3326                         goto failed_mount;
3327                 }
3328
3329                 brelse(bh);
3330                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3331                 offset = do_div(logical_sb_block, blocksize);
3332                 bh = sb_bread(sb, logical_sb_block);
3333                 if (!bh) {
3334                         ext4_msg(sb, KERN_ERR,
3335                                "Can't read superblock on 2nd try");
3336                         goto failed_mount;
3337                 }
3338                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3339                 sbi->s_es = es;
3340                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3341                         ext4_msg(sb, KERN_ERR,
3342                                "Magic mismatch, very weird!");
3343                         goto failed_mount;
3344                 }
3345         }
3346
3347         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3348                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3349         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3350                                                       has_huge_files);
3351         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3352
3353         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3354                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3355                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3356         } else {
3357                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3358                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3359                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3360                     (!is_power_of_2(sbi->s_inode_size)) ||
3361                     (sbi->s_inode_size > blocksize)) {
3362                         ext4_msg(sb, KERN_ERR,
3363                                "unsupported inode size: %d",
3364                                sbi->s_inode_size);
3365                         goto failed_mount;
3366                 }
3367                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3368                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3369         }
3370
3371         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3372         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3373                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3374                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3375                     !is_power_of_2(sbi->s_desc_size)) {
3376                         ext4_msg(sb, KERN_ERR,
3377                                "unsupported descriptor size %lu",
3378                                sbi->s_desc_size);
3379                         goto failed_mount;
3380                 }
3381         } else
3382                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3383
3384         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3385         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3386         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3387                 goto cantfind_ext4;
3388
3389         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3390         if (sbi->s_inodes_per_block == 0)
3391                 goto cantfind_ext4;
3392         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3393                                         sbi->s_inodes_per_block;
3394         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3395         sbi->s_sbh = bh;
3396         sbi->s_mount_state = le16_to_cpu(es->s_state);
3397         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3398         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3399
3400         for (i = 0; i < 4; i++)
3401                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3402         sbi->s_def_hash_version = es->s_def_hash_version;
3403         i = le32_to_cpu(es->s_flags);
3404         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3405                 sbi->s_hash_unsigned = 3;
3406         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3407 #ifdef __CHAR_UNSIGNED__
3408                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3409                 sbi->s_hash_unsigned = 3;
3410 #else
3411                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3412 #endif
3413                 sb->s_dirt = 1;
3414         }
3415
3416         /* Handle clustersize */
3417         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3418         has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3419                                 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3420         if (has_bigalloc) {
3421                 if (clustersize < blocksize) {
3422                         ext4_msg(sb, KERN_ERR,
3423                                  "cluster size (%d) smaller than "
3424                                  "block size (%d)", clustersize, blocksize);
3425                         goto failed_mount;
3426                 }
3427                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3428                         le32_to_cpu(es->s_log_block_size);
3429                 sbi->s_clusters_per_group =
3430                         le32_to_cpu(es->s_clusters_per_group);
3431                 if (sbi->s_clusters_per_group > blocksize * 8) {
3432                         ext4_msg(sb, KERN_ERR,
3433                                  "#clusters per group too big: %lu",
3434                                  sbi->s_clusters_per_group);
3435                         goto failed_mount;
3436                 }
3437                 if (sbi->s_blocks_per_group !=
3438                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3439                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3440                                  "clusters per group (%lu) inconsistent",
3441                                  sbi->s_blocks_per_group,
3442                                  sbi->s_clusters_per_group);
3443                         goto failed_mount;
3444                 }
3445         } else {
3446                 if (clustersize != blocksize) {
3447                         ext4_warning(sb, "fragment/cluster size (%d) != "
3448                                      "block size (%d)", clustersize,
3449                                      blocksize);
3450                         clustersize = blocksize;
3451                 }
3452                 if (sbi->s_blocks_per_group > blocksize * 8) {
3453                         ext4_msg(sb, KERN_ERR,
3454                                  "#blocks per group too big: %lu",
3455                                  sbi->s_blocks_per_group);
3456                         goto failed_mount;
3457                 }
3458                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3459                 sbi->s_cluster_bits = 0;
3460         }
3461         sbi->s_cluster_ratio = clustersize / blocksize;
3462
3463         if (sbi->s_inodes_per_group > blocksize * 8) {
3464                 ext4_msg(sb, KERN_ERR,
3465                        "#inodes per group too big: %lu",
3466                        sbi->s_inodes_per_group);
3467                 goto failed_mount;
3468         }
3469
3470         /*
3471          * Test whether we have more sectors than will fit in sector_t,
3472          * and whether the max offset is addressable by the page cache.
3473          */
3474         err = generic_check_addressable(sb->s_blocksize_bits,
3475                                         ext4_blocks_count(es));
3476         if (err) {
3477                 ext4_msg(sb, KERN_ERR, "filesystem"
3478                          " too large to mount safely on this system");
3479                 if (sizeof(sector_t) < 8)
3480                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3481                 ret = err;
3482                 goto failed_mount;
3483         }
3484
3485         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3486                 goto cantfind_ext4;
3487
3488         /* check blocks count against device size */
3489         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3490         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3491                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3492                        "exceeds size of device (%llu blocks)",
3493                        ext4_blocks_count(es), blocks_count);
3494                 goto failed_mount;
3495         }
3496
3497         /*
3498          * It makes no sense for the first data block to be beyond the end
3499          * of the filesystem.
3500          */
3501         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3502                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3503                          "block %u is beyond end of filesystem (%llu)",
3504                          le32_to_cpu(es->s_first_data_block),
3505                          ext4_blocks_count(es));
3506                 goto failed_mount;
3507         }
3508         blocks_count = (ext4_blocks_count(es) -
3509                         le32_to_cpu(es->s_first_data_block) +
3510                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3511         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3512         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3513                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3514                        "(block count %llu, first data block %u, "
3515                        "blocks per group %lu)", sbi->s_groups_count,
3516                        ext4_blocks_count(es),
3517                        le32_to_cpu(es->s_first_data_block),
3518                        EXT4_BLOCKS_PER_GROUP(sb));
3519                 goto failed_mount;
3520         }
3521         sbi->s_groups_count = blocks_count;
3522         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3523                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3524         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3525                    EXT4_DESC_PER_BLOCK(sb);
3526         sbi->s_group_desc = ext4_kvmalloc(db_count *
3527                                           sizeof(struct buffer_head *),
3528                                           GFP_KERNEL);
3529         if (sbi->s_group_desc == NULL) {
3530                 ext4_msg(sb, KERN_ERR, "not enough memory");
3531                 goto failed_mount;
3532         }
3533
3534 #ifdef CONFIG_PROC_FS
3535         if (ext4_proc_root)
3536                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3537 #endif
3538
3539         bgl_lock_init(sbi->s_blockgroup_lock);
3540
3541         for (i = 0; i < db_count; i++) {
3542                 block = descriptor_loc(sb, logical_sb_block, i);
3543                 sbi->s_group_desc[i] = sb_bread(sb, block);
3544                 if (!sbi->s_group_desc[i]) {
3545                         ext4_msg(sb, KERN_ERR,
3546                                "can't read group descriptor %d", i);
3547                         db_count = i;
3548                         goto failed_mount2;
3549                 }
3550         }
3551         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3552                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3553                 goto failed_mount2;
3554         }
3555         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3556                 if (!ext4_fill_flex_info(sb)) {
3557                         ext4_msg(sb, KERN_ERR,
3558                                "unable to initialize "
3559                                "flex_bg meta info!");
3560                         goto failed_mount2;
3561                 }
3562
3563         sbi->s_gdb_count = db_count;
3564         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3565         spin_lock_init(&sbi->s_next_gen_lock);
3566
3567         init_timer(&sbi->s_err_report);
3568         sbi->s_err_report.function = print_daily_error_info;
3569         sbi->s_err_report.data = (unsigned long) sb;
3570
3571         err = percpu_counter_init(&sbi->s_freeblocks_counter,
3572                         ext4_count_free_blocks(sb));
3573         if (!err) {
3574                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3575                                 ext4_count_free_inodes(sb));
3576         }
3577         if (!err) {
3578                 err = percpu_counter_init(&sbi->s_dirs_counter,
3579                                 ext4_count_dirs(sb));
3580         }
3581         if (!err) {
3582                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
3583         }
3584         if (err) {
3585                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3586                 goto failed_mount3;
3587         }
3588
3589         sbi->s_stripe = ext4_get_stripe_size(sbi);
3590         sbi->s_max_writeback_mb_bump = 128;
3591
3592         /*
3593          * set up enough so that it can read an inode
3594          */
3595         if (!test_opt(sb, NOLOAD) &&
3596             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3597                 sb->s_op = &ext4_sops;
3598         else
3599                 sb->s_op = &ext4_nojournal_sops;
3600         sb->s_export_op = &ext4_export_ops;
3601         sb->s_xattr = ext4_xattr_handlers;
3602 #ifdef CONFIG_QUOTA
3603         sb->s_qcop = &ext4_qctl_operations;
3604         sb->dq_op = &ext4_quota_operations;
3605 #endif
3606         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3607
3608         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3609         mutex_init(&sbi->s_orphan_lock);
3610         sbi->s_resize_flags = 0;
3611
3612         sb->s_root = NULL;
3613
3614         needs_recovery = (es->s_last_orphan != 0 ||
3615                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3616                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3617
3618         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3619             !(sb->s_flags & MS_RDONLY))
3620                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3621                         goto failed_mount3;
3622
3623         /*
3624          * The first inode we look at is the journal inode.  Don't try
3625          * root first: it may be modified in the journal!
3626          */
3627         if (!test_opt(sb, NOLOAD) &&
3628             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3629                 if (ext4_load_journal(sb, es, journal_devnum))
3630                         goto failed_mount3;
3631         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3632               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3633                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3634                        "suppressed and not mounted read-only");
3635                 goto failed_mount_wq;
3636         } else {
3637                 clear_opt(sb, DATA_FLAGS);
3638                 sbi->s_journal = NULL;
3639                 needs_recovery = 0;
3640                 goto no_journal;
3641         }
3642
3643         if (ext4_blocks_count(es) > 0xffffffffULL &&
3644             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3645                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3646                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3647                 goto failed_mount_wq;
3648         }
3649
3650         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3651                 jbd2_journal_set_features(sbi->s_journal,
3652                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3653                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3654         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3655                 jbd2_journal_set_features(sbi->s_journal,
3656                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3657                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3658                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3659         } else {
3660                 jbd2_journal_clear_features(sbi->s_journal,
3661                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3662                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3663         }
3664
3665         /* We have now updated the journal if required, so we can
3666          * validate the data journaling mode. */
3667         switch (test_opt(sb, DATA_FLAGS)) {
3668         case 0:
3669                 /* No mode set, assume a default based on the journal
3670                  * capabilities: ORDERED_DATA if the journal can
3671                  * cope, else JOURNAL_DATA
3672                  */
3673                 if (jbd2_journal_check_available_features
3674                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3675                         set_opt(sb, ORDERED_DATA);
3676                 else
3677                         set_opt(sb, JOURNAL_DATA);
3678                 break;
3679
3680         case EXT4_MOUNT_ORDERED_DATA:
3681         case EXT4_MOUNT_WRITEBACK_DATA:
3682                 if (!jbd2_journal_check_available_features
3683                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3684                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3685                                "requested data journaling mode");
3686                         goto failed_mount_wq;
3687                 }
3688         default:
3689                 break;
3690         }
3691         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3692
3693         /*
3694          * The journal may have updated the bg summary counts, so we
3695          * need to update the global counters.
3696          */
3697         percpu_counter_set(&sbi->s_freeblocks_counter,
3698                            ext4_count_free_blocks(sb));
3699         percpu_counter_set(&sbi->s_freeinodes_counter,
3700                            ext4_count_free_inodes(sb));
3701         percpu_counter_set(&sbi->s_dirs_counter,
3702                            ext4_count_dirs(sb));
3703         percpu_counter_set(&sbi->s_dirtyblocks_counter, 0);
3704
3705 no_journal:
3706         /*
3707          * The maximum number of concurrent works can be high and
3708          * concurrency isn't really necessary.  Limit it to 1.
3709          */
3710         EXT4_SB(sb)->dio_unwritten_wq =
3711                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3712         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3713                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3714                 goto failed_mount_wq;
3715         }
3716
3717         /*
3718          * The jbd2_journal_load will have done any necessary log recovery,
3719          * so we can safely mount the rest of the filesystem now.
3720          */
3721
3722         root = ext4_iget(sb, EXT4_ROOT_INO);
3723         if (IS_ERR(root)) {
3724                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3725                 ret = PTR_ERR(root);
3726                 root = NULL;
3727                 goto failed_mount4;
3728         }
3729         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3730                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3731                 goto failed_mount4;
3732         }
3733         sb->s_root = d_alloc_root(root);
3734         if (!sb->s_root) {
3735                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3736                 ret = -ENOMEM;
3737                 goto failed_mount4;
3738         }
3739
3740         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3741
3742         /* determine the minimum size of new large inodes, if present */
3743         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3744                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3745                                                      EXT4_GOOD_OLD_INODE_SIZE;
3746                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3747                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3748                         if (sbi->s_want_extra_isize <
3749                             le16_to_cpu(es->s_want_extra_isize))
3750                                 sbi->s_want_extra_isize =
3751                                         le16_to_cpu(es->s_want_extra_isize);
3752                         if (sbi->s_want_extra_isize <
3753                             le16_to_cpu(es->s_min_extra_isize))
3754                                 sbi->s_want_extra_isize =
3755                                         le16_to_cpu(es->s_min_extra_isize);
3756                 }
3757         }
3758         /* Check if enough inode space is available */
3759         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3760                                                         sbi->s_inode_size) {
3761                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3762                                                        EXT4_GOOD_OLD_INODE_SIZE;
3763                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3764                          "available");
3765         }
3766
3767         err = ext4_setup_system_zone(sb);
3768         if (err) {
3769                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3770                          "zone (%d)", err);
3771                 goto failed_mount4;
3772         }
3773
3774         ext4_ext_init(sb);
3775         err = ext4_mb_init(sb, needs_recovery);
3776         if (err) {
3777                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3778                          err);
3779                 goto failed_mount4;
3780         }
3781
3782         err = ext4_register_li_request(sb, first_not_zeroed);
3783         if (err)
3784                 goto failed_mount4;
3785
3786         sbi->s_kobj.kset = ext4_kset;
3787         init_completion(&sbi->s_kobj_unregister);
3788         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3789                                    "%s", sb->s_id);
3790         if (err) {
3791                 ext4_mb_release(sb);
3792                 ext4_ext_release(sb);
3793                 goto failed_mount4;
3794         };
3795
3796         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3797         ext4_orphan_cleanup(sb, es);
3798         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3799         if (needs_recovery) {
3800                 ext4_msg(sb, KERN_INFO, "recovery complete");
3801                 ext4_mark_recovery_complete(sb, es);
3802         }
3803         if (EXT4_SB(sb)->s_journal) {
3804                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3805                         descr = " journalled data mode";
3806                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3807                         descr = " ordered data mode";
3808                 else
3809                         descr = " writeback data mode";
3810         } else
3811                 descr = "out journal";
3812
3813         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3814                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3815                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3816
3817         if (es->s_error_count)
3818                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3819
3820         kfree(orig_data);
3821         return 0;
3822
3823 cantfind_ext4:
3824         if (!silent)
3825                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3826         goto failed_mount;
3827
3828 failed_mount4:
3829         iput(root);
3830         sb->s_root = NULL;
3831         ext4_msg(sb, KERN_ERR, "mount failed");
3832         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3833 failed_mount_wq:
3834         ext4_release_system_zone(sb);
3835         if (sbi->s_journal) {
3836                 jbd2_journal_destroy(sbi->s_journal);
3837                 sbi->s_journal = NULL;
3838         }
3839 failed_mount3:
3840         del_timer(&sbi->s_err_report);
3841         if (sbi->s_flex_groups)
3842                 ext4_kvfree(sbi->s_flex_groups);
3843         percpu_counter_destroy(&sbi->s_freeblocks_counter);
3844         percpu_counter_destroy(&sbi->s_freeinodes_counter);
3845         percpu_counter_destroy(&sbi->s_dirs_counter);
3846         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
3847         if (sbi->s_mmp_tsk)
3848                 kthread_stop(sbi->s_mmp_tsk);
3849 failed_mount2:
3850         for (i = 0; i < db_count; i++)
3851                 brelse(sbi->s_group_desc[i]);
3852         ext4_kvfree(sbi->s_group_desc);
3853 failed_mount:
3854         if (sbi->s_proc) {
3855                 remove_proc_entry(sb->s_id, ext4_proc_root);
3856         }
3857 #ifdef CONFIG_QUOTA
3858         for (i = 0; i < MAXQUOTAS; i++)
3859                 kfree(sbi->s_qf_names[i]);
3860 #endif
3861         ext4_blkdev_remove(sbi);
3862         brelse(bh);
3863 out_fail:
3864         sb->s_fs_info = NULL;
3865         kfree(sbi->s_blockgroup_lock);
3866         kfree(sbi);
3867 out_free_orig:
3868         kfree(orig_data);
3869         return ret;
3870 }
3871
3872 /*
3873  * Setup any per-fs journal parameters now.  We'll do this both on
3874  * initial mount, once the journal has been initialised but before we've
3875  * done any recovery; and again on any subsequent remount.
3876  */
3877 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3878 {
3879         struct ext4_sb_info *sbi = EXT4_SB(sb);
3880
3881         journal->j_commit_interval = sbi->s_commit_interval;
3882         journal->j_min_batch_time = sbi->s_min_batch_time;
3883         journal->j_max_batch_time = sbi->s_max_batch_time;
3884
3885         write_lock(&journal->j_state_lock);
3886         if (test_opt(sb, BARRIER))
3887                 journal->j_flags |= JBD2_BARRIER;
3888         else
3889                 journal->j_flags &= ~JBD2_BARRIER;
3890         if (test_opt(sb, DATA_ERR_ABORT))
3891                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3892         else
3893                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3894         write_unlock(&journal->j_state_lock);
3895 }
3896
3897 static journal_t *ext4_get_journal(struct super_block *sb,
3898                                    unsigned int journal_inum)
3899 {
3900         struct inode *journal_inode;
3901         journal_t *journal;
3902
3903         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3904
3905         /* First, test for the existence of a valid inode on disk.  Bad
3906          * things happen if we iget() an unused inode, as the subsequent
3907          * iput() will try to delete it. */
3908
3909         journal_inode = ext4_iget(sb, journal_inum);
3910         if (IS_ERR(journal_inode)) {
3911                 ext4_msg(sb, KERN_ERR, "no journal found");
3912                 return NULL;
3913         }
3914         if (!journal_inode->i_nlink) {
3915                 make_bad_inode(journal_inode);
3916                 iput(journal_inode);
3917                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3918                 return NULL;
3919         }
3920
3921         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3922                   journal_inode, journal_inode->i_size);
3923         if (!S_ISREG(journal_inode->i_mode)) {
3924                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3925                 iput(journal_inode);
3926                 return NULL;
3927         }
3928
3929         journal = jbd2_journal_init_inode(journal_inode);
3930         if (!journal) {
3931                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3932                 iput(journal_inode);
3933                 return NULL;
3934         }
3935         journal->j_private = sb;
3936         ext4_init_journal_params(sb, journal);
3937         return journal;
3938 }
3939
3940 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3941                                        dev_t j_dev)
3942 {
3943         struct buffer_head *bh;
3944         journal_t *journal;
3945         ext4_fsblk_t start;
3946         ext4_fsblk_t len;
3947         int hblock, blocksize;
3948         ext4_fsblk_t sb_block;
3949         unsigned long offset;
3950         struct ext4_super_block *es;
3951         struct block_device *bdev;
3952
3953         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3954
3955         bdev = ext4_blkdev_get(j_dev, sb);
3956         if (bdev == NULL)
3957                 return NULL;
3958
3959         blocksize = sb->s_blocksize;
3960         hblock = bdev_logical_block_size(bdev);
3961         if (blocksize < hblock) {
3962                 ext4_msg(sb, KERN_ERR,
3963                         "blocksize too small for journal device");
3964                 goto out_bdev;
3965         }
3966
3967         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3968         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3969         set_blocksize(bdev, blocksize);
3970         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3971                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3972                        "external journal");
3973                 goto out_bdev;
3974         }
3975
3976         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3977         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3978             !(le32_to_cpu(es->s_feature_incompat) &
3979               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3980                 ext4_msg(sb, KERN_ERR, "external journal has "
3981                                         "bad superblock");
3982                 brelse(bh);
3983                 goto out_bdev;
3984         }
3985
3986         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3987                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3988                 brelse(bh);
3989                 goto out_bdev;
3990         }
3991
3992         len = ext4_blocks_count(es);
3993         start = sb_block + 1;
3994         brelse(bh);     /* we're done with the superblock */
3995
3996         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3997                                         start, len, blocksize);
3998         if (!journal) {
3999                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4000                 goto out_bdev;
4001         }
4002         journal->j_private = sb;
4003         ll_rw_block(READ, 1, &journal->j_sb_buffer);
4004         wait_on_buffer(journal->j_sb_buffer);
4005         if (!buffer_uptodate(journal->j_sb_buffer)) {
4006                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4007                 goto out_journal;
4008         }
4009         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4010                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4011                                         "user (unsupported) - %d",
4012                         be32_to_cpu(journal->j_superblock->s_nr_users));
4013                 goto out_journal;
4014         }
4015         EXT4_SB(sb)->journal_bdev = bdev;
4016         ext4_init_journal_params(sb, journal);
4017         return journal;
4018
4019 out_journal:
4020         jbd2_journal_destroy(journal);
4021 out_bdev:
4022         ext4_blkdev_put(bdev);
4023         return NULL;
4024 }
4025
4026 static int ext4_load_journal(struct super_block *sb,
4027                              struct ext4_super_block *es,
4028                              unsigned long journal_devnum)
4029 {
4030         journal_t *journal;
4031         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4032         dev_t journal_dev;
4033         int err = 0;
4034         int really_read_only;
4035
4036         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4037
4038         if (journal_devnum &&
4039             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4040                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4041                         "numbers have changed");
4042                 journal_dev = new_decode_dev(journal_devnum);
4043         } else
4044                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4045
4046         really_read_only = bdev_read_only(sb->s_bdev);
4047
4048         /*
4049          * Are we loading a blank journal or performing recovery after a
4050          * crash?  For recovery, we need to check in advance whether we
4051          * can get read-write access to the device.
4052          */
4053         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4054                 if (sb->s_flags & MS_RDONLY) {
4055                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4056                                         "required on readonly filesystem");
4057                         if (really_read_only) {
4058                                 ext4_msg(sb, KERN_ERR, "write access "
4059                                         "unavailable, cannot proceed");
4060                                 return -EROFS;
4061                         }
4062                         ext4_msg(sb, KERN_INFO, "write access will "
4063                                "be enabled during recovery");
4064                 }
4065         }
4066
4067         if (journal_inum && journal_dev) {
4068                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4069                        "and inode journals!");
4070                 return -EINVAL;
4071         }
4072
4073         if (journal_inum) {
4074                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4075                         return -EINVAL;
4076         } else {
4077                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4078                         return -EINVAL;
4079         }
4080
4081         if (!(journal->j_flags & JBD2_BARRIER))
4082                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4083
4084         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
4085                 err = jbd2_journal_update_format(journal);
4086                 if (err)  {
4087                         ext4_msg(sb, KERN_ERR, "error updating journal");
4088                         jbd2_journal_destroy(journal);
4089                         return err;
4090                 }
4091         }
4092
4093         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4094                 err = jbd2_journal_wipe(journal, !really_read_only);
4095         if (!err) {
4096                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4097                 if (save)
4098                         memcpy(save, ((char *) es) +
4099                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4100                 err = jbd2_journal_load(journal);
4101                 if (save)
4102                         memcpy(((char *) es) + EXT4_S_ERR_START,
4103                                save, EXT4_S_ERR_LEN);
4104                 kfree(save);
4105         }
4106
4107         if (err) {
4108                 ext4_msg(sb, KERN_ERR, "error loading journal");
4109                 jbd2_journal_destroy(journal);
4110                 return err;
4111         }
4112
4113         EXT4_SB(sb)->s_journal = journal;
4114         ext4_clear_journal_err(sb, es);
4115
4116         if (!really_read_only && journal_devnum &&
4117             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4118                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4119
4120                 /* Make sure we flush the recovery flag to disk. */
4121                 ext4_commit_super(sb, 1);
4122         }
4123
4124         return 0;
4125 }
4126
4127 static int ext4_commit_super(struct super_block *sb, int sync)
4128 {
4129         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4130         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4131         int error = 0;
4132
4133         if (!sbh || block_device_ejected(sb))
4134                 return error;
4135         if (buffer_write_io_error(sbh)) {
4136                 /*
4137                  * Oh, dear.  A previous attempt to write the
4138                  * superblock failed.  This could happen because the
4139                  * USB device was yanked out.  Or it could happen to
4140                  * be a transient write error and maybe the block will
4141                  * be remapped.  Nothing we can do but to retry the
4142                  * write and hope for the best.
4143                  */
4144                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4145                        "superblock detected");
4146                 clear_buffer_write_io_error(sbh);
4147                 set_buffer_uptodate(sbh);
4148         }
4149         /*
4150          * If the file system is mounted read-only, don't update the
4151          * superblock write time.  This avoids updating the superblock
4152          * write time when we are mounting the root file system
4153          * read/only but we need to replay the journal; at that point,
4154          * for people who are east of GMT and who make their clock
4155          * tick in localtime for Windows bug-for-bug compatibility,
4156          * the clock is set in the future, and this will cause e2fsck
4157          * to complain and force a full file system check.
4158          */
4159         if (!(sb->s_flags & MS_RDONLY))
4160                 es->s_wtime = cpu_to_le32(get_seconds());
4161         if (sb->s_bdev->bd_part)
4162                 es->s_kbytes_written =
4163                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4164                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4165                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4166         else
4167                 es->s_kbytes_written =
4168                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4169         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
4170                                            &EXT4_SB(sb)->s_freeblocks_counter));
4171         es->s_free_inodes_count =
4172                 cpu_to_le32(percpu_counter_sum_positive(
4173                                 &EXT4_SB(sb)->s_freeinodes_counter));
4174         sb->s_dirt = 0;
4175         BUFFER_TRACE(sbh, "marking dirty");
4176         mark_buffer_dirty(sbh);
4177         if (sync) {
4178                 error = sync_dirty_buffer(sbh);
4179                 if (error)
4180                         return error;
4181
4182                 error = buffer_write_io_error(sbh);
4183                 if (error) {
4184                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4185                                "superblock");
4186                         clear_buffer_write_io_error(sbh);
4187                         set_buffer_uptodate(sbh);
4188                 }
4189         }
4190         return error;
4191 }
4192
4193 /*
4194  * Have we just finished recovery?  If so, and if we are mounting (or
4195  * remounting) the filesystem readonly, then we will end up with a
4196  * consistent fs on disk.  Record that fact.
4197  */
4198 static void ext4_mark_recovery_complete(struct super_block *sb,
4199                                         struct ext4_super_block *es)
4200 {
4201         journal_t *journal = EXT4_SB(sb)->s_journal;
4202
4203         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4204                 BUG_ON(journal != NULL);
4205                 return;
4206         }
4207         jbd2_journal_lock_updates(journal);
4208         if (jbd2_journal_flush(journal) < 0)
4209                 goto out;
4210
4211         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4212             sb->s_flags & MS_RDONLY) {
4213                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4214                 ext4_commit_super(sb, 1);
4215         }
4216
4217 out:
4218         jbd2_journal_unlock_updates(journal);
4219 }
4220
4221 /*
4222  * If we are mounting (or read-write remounting) a filesystem whose journal
4223  * has recorded an error from a previous lifetime, move that error to the
4224  * main filesystem now.
4225  */
4226 static void ext4_clear_journal_err(struct super_block *sb,
4227                                    struct ext4_super_block *es)
4228 {
4229         journal_t *journal;
4230         int j_errno;
4231         const char *errstr;
4232
4233         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4234
4235         journal = EXT4_SB(sb)->s_journal;
4236
4237         /*
4238          * Now check for any error status which may have been recorded in the
4239          * journal by a prior ext4_error() or ext4_abort()
4240          */
4241
4242         j_errno = jbd2_journal_errno(journal);
4243         if (j_errno) {
4244                 char nbuf[16];
4245
4246                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4247                 ext4_warning(sb, "Filesystem error recorded "
4248                              "from previous mount: %s", errstr);
4249                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4250
4251                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4252                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4253                 ext4_commit_super(sb, 1);
4254
4255                 jbd2_journal_clear_err(journal);
4256         }
4257 }
4258
4259 /*
4260  * Force the running and committing transactions to commit,
4261  * and wait on the commit.
4262  */
4263 int ext4_force_commit(struct super_block *sb)
4264 {
4265         journal_t *journal;
4266         int ret = 0;
4267
4268         if (sb->s_flags & MS_RDONLY)
4269                 return 0;
4270
4271         journal = EXT4_SB(sb)->s_journal;
4272         if (journal) {
4273                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
4274                 ret = ext4_journal_force_commit(journal);
4275         }
4276
4277         return ret;
4278 }
4279
4280 static void ext4_write_super(struct super_block *sb)
4281 {
4282         lock_super(sb);
4283         ext4_commit_super(sb, 1);
4284         unlock_super(sb);
4285 }
4286
4287 static int ext4_sync_fs(struct super_block *sb, int wait)
4288 {
4289         int ret = 0;
4290         tid_t target;
4291         struct ext4_sb_info *sbi = EXT4_SB(sb);
4292
4293         trace_ext4_sync_fs(sb, wait);
4294         flush_workqueue(sbi->dio_unwritten_wq);
4295         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4296                 if (wait)
4297                         jbd2_log_wait_commit(sbi->s_journal, target);
4298         }
4299         return ret;
4300 }
4301
4302 /*
4303  * LVM calls this function before a (read-only) snapshot is created.  This
4304  * gives us a chance to flush the journal completely and mark the fs clean.
4305  *
4306  * Note that only this function cannot bring a filesystem to be in a clean
4307  * state independently, because ext4 prevents a new handle from being started
4308  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4309  * the upper layer.
4310  */
4311 static int ext4_freeze(struct super_block *sb)
4312 {
4313         int error = 0;
4314         journal_t *journal;
4315
4316         if (sb->s_flags & MS_RDONLY)
4317                 return 0;
4318
4319         journal = EXT4_SB(sb)->s_journal;
4320
4321         /* Now we set up the journal barrier. */
4322         jbd2_journal_lock_updates(journal);
4323
4324         /*
4325          * Don't clear the needs_recovery flag if we failed to flush
4326          * the journal.
4327          */
4328         error = jbd2_journal_flush(journal);
4329         if (error < 0)
4330                 goto out;
4331
4332         /* Journal blocked and flushed, clear needs_recovery flag. */
4333         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4334         error = ext4_commit_super(sb, 1);
4335 out:
4336         /* we rely on s_frozen to stop further updates */
4337         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4338         return error;
4339 }
4340
4341 /*
4342  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4343  * flag here, even though the filesystem is not technically dirty yet.
4344  */
4345 static int ext4_unfreeze(struct super_block *sb)
4346 {
4347         if (sb->s_flags & MS_RDONLY)
4348                 return 0;
4349
4350         lock_super(sb);
4351         /* Reset the needs_recovery flag before the fs is unlocked. */
4352         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4353         ext4_commit_super(sb, 1);
4354         unlock_super(sb);
4355         return 0;
4356 }
4357
4358 /*
4359  * Structure to save mount options for ext4_remount's benefit
4360  */
4361 struct ext4_mount_options {
4362         unsigned long s_mount_opt;
4363         unsigned long s_mount_opt2;
4364         uid_t s_resuid;
4365         gid_t s_resgid;
4366         unsigned long s_commit_interval;
4367         u32 s_min_batch_time, s_max_batch_time;
4368 #ifdef CONFIG_QUOTA
4369         int s_jquota_fmt;
4370         char *s_qf_names[MAXQUOTAS];
4371 #endif
4372 };
4373
4374 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4375 {
4376         struct ext4_super_block *es;
4377         struct ext4_sb_info *sbi = EXT4_SB(sb);
4378         ext4_fsblk_t n_blocks_count = 0;
4379         unsigned long old_sb_flags;
4380         struct ext4_mount_options old_opts;
4381         int enable_quota = 0;
4382         ext4_group_t g;
4383         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4384         int err = 0;
4385 #ifdef CONFIG_QUOTA
4386         int i;
4387 #endif
4388         char *orig_data = kstrdup(data, GFP_KERNEL);
4389
4390         /* Store the original options */
4391         lock_super(sb);
4392         old_sb_flags = sb->s_flags;
4393         old_opts.s_mount_opt = sbi->s_mount_opt;
4394         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4395         old_opts.s_resuid = sbi->s_resuid;
4396         old_opts.s_resgid = sbi->s_resgid;
4397         old_opts.s_commit_interval = sbi->s_commit_interval;
4398         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4399         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4400 #ifdef CONFIG_QUOTA
4401         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4402         for (i = 0; i < MAXQUOTAS; i++)
4403                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4404 #endif
4405         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4406                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4407
4408         /*
4409          * Allow the "check" option to be passed as a remount option.
4410          */
4411         if (!parse_options(data, sb, NULL, &journal_ioprio,
4412                            &n_blocks_count, 1)) {
4413                 err = -EINVAL;
4414                 goto restore_opts;
4415         }
4416
4417         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4418                 ext4_abort(sb, "Abort forced by user");
4419
4420         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4421                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4422
4423         es = sbi->s_es;
4424
4425         if (sbi->s_journal) {
4426                 ext4_init_journal_params(sb, sbi->s_journal);
4427                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4428         }
4429
4430         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4431                 n_blocks_count > ext4_blocks_count(es)) {
4432                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4433                         err = -EROFS;
4434                         goto restore_opts;
4435                 }
4436
4437                 if (*flags & MS_RDONLY) {
4438                         err = dquot_suspend(sb, -1);
4439                         if (err < 0)
4440                                 goto restore_opts;
4441
4442                         /*
4443                          * First of all, the unconditional stuff we have to do
4444                          * to disable replay of the journal when we next remount
4445                          */
4446                         sb->s_flags |= MS_RDONLY;
4447
4448                         /*
4449                          * OK, test if we are remounting a valid rw partition
4450                          * readonly, and if so set the rdonly flag and then
4451                          * mark the partition as valid again.
4452                          */
4453                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4454                             (sbi->s_mount_state & EXT4_VALID_FS))
4455                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4456
4457                         if (sbi->s_journal)
4458                                 ext4_mark_recovery_complete(sb, es);
4459                 } else {
4460                         /* Make sure we can mount this feature set readwrite */
4461                         if (!ext4_feature_set_ok(sb, 0)) {
4462                                 err = -EROFS;
4463                                 goto restore_opts;
4464                         }
4465                         /*
4466                          * Make sure the group descriptor checksums
4467                          * are sane.  If they aren't, refuse to remount r/w.
4468                          */
4469                         for (g = 0; g < sbi->s_groups_count; g++) {
4470                                 struct ext4_group_desc *gdp =
4471                                         ext4_get_group_desc(sb, g, NULL);
4472
4473                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4474                                         ext4_msg(sb, KERN_ERR,
4475                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4476                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4477                                                le16_to_cpu(gdp->bg_checksum));
4478                                         err = -EINVAL;
4479                                         goto restore_opts;
4480                                 }
4481                         }
4482
4483                         /*
4484                          * If we have an unprocessed orphan list hanging
4485                          * around from a previously readonly bdev mount,
4486                          * require a full umount/remount for now.
4487                          */
4488                         if (es->s_last_orphan) {
4489                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4490                                        "remount RDWR because of unprocessed "
4491                                        "orphan inode list.  Please "
4492                                        "umount/remount instead");
4493                                 err = -EINVAL;
4494                                 goto restore_opts;
4495                         }
4496
4497                         /*
4498                          * Mounting a RDONLY partition read-write, so reread
4499                          * and store the current valid flag.  (It may have
4500                          * been changed by e2fsck since we originally mounted
4501                          * the partition.)
4502                          */
4503                         if (sbi->s_journal)
4504                                 ext4_clear_journal_err(sb, es);
4505                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4506                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4507                                 goto restore_opts;
4508                         if (!ext4_setup_super(sb, es, 0))
4509                                 sb->s_flags &= ~MS_RDONLY;
4510                         if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4511                                                      EXT4_FEATURE_INCOMPAT_MMP))
4512                                 if (ext4_multi_mount_protect(sb,
4513                                                 le64_to_cpu(es->s_mmp_block))) {
4514                                         err = -EROFS;
4515                                         goto restore_opts;
4516                                 }
4517                         enable_quota = 1;
4518                 }
4519         }
4520
4521         /*
4522          * Reinitialize lazy itable initialization thread based on
4523          * current settings
4524          */
4525         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4526                 ext4_unregister_li_request(sb);
4527         else {
4528                 ext4_group_t first_not_zeroed;
4529                 first_not_zeroed = ext4_has_uninit_itable(sb);
4530                 ext4_register_li_request(sb, first_not_zeroed);
4531         }
4532
4533         ext4_setup_system_zone(sb);
4534         if (sbi->s_journal == NULL)
4535                 ext4_commit_super(sb, 1);
4536
4537 #ifdef CONFIG_QUOTA
4538         /* Release old quota file names */
4539         for (i = 0; i < MAXQUOTAS; i++)
4540                 if (old_opts.s_qf_names[i] &&
4541                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4542                         kfree(old_opts.s_qf_names[i]);
4543 #endif
4544         unlock_super(sb);
4545         if (enable_quota)
4546                 dquot_resume(sb, -1);
4547
4548         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4549         kfree(orig_data);
4550         return 0;
4551
4552 restore_opts:
4553         sb->s_flags = old_sb_flags;
4554         sbi->s_mount_opt = old_opts.s_mount_opt;
4555         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4556         sbi->s_resuid = old_opts.s_resuid;
4557         sbi->s_resgid = old_opts.s_resgid;
4558         sbi->s_commit_interval = old_opts.s_commit_interval;
4559         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4560         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4561 #ifdef CONFIG_QUOTA
4562         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4563         for (i = 0; i < MAXQUOTAS; i++) {
4564                 if (sbi->s_qf_names[i] &&
4565                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4566                         kfree(sbi->s_qf_names[i]);
4567                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4568         }
4569 #endif
4570         unlock_super(sb);
4571         kfree(orig_data);
4572         return err;
4573 }
4574
4575 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4576 {
4577         struct super_block *sb = dentry->d_sb;
4578         struct ext4_sb_info *sbi = EXT4_SB(sb);
4579         struct ext4_super_block *es = sbi->s_es;
4580         u64 fsid;
4581         s64 bfree;
4582
4583         if (test_opt(sb, MINIX_DF)) {
4584                 sbi->s_overhead_last = 0;
4585         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4586                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4587                 ext4_fsblk_t overhead = 0;
4588
4589                 /*
4590                  * Compute the overhead (FS structures).  This is constant
4591                  * for a given filesystem unless the number of block groups
4592                  * changes so we cache the previous value until it does.
4593                  */
4594
4595                 /*
4596                  * All of the blocks before first_data_block are
4597                  * overhead
4598                  */
4599                 overhead = le32_to_cpu(es->s_first_data_block);
4600
4601                 /*
4602                  * Add the overhead attributed to the superblock and
4603                  * block group descriptors.  If the sparse superblocks
4604                  * feature is turned on, then not all groups have this.
4605                  */
4606                 for (i = 0; i < ngroups; i++) {
4607                         overhead += ext4_bg_has_super(sb, i) +
4608                                 ext4_bg_num_gdb(sb, i);
4609                         cond_resched();
4610                 }
4611
4612                 /*
4613                  * Every block group has an inode bitmap, a block
4614                  * bitmap, and an inode table.
4615                  */
4616                 overhead += ngroups * (2 + sbi->s_itb_per_group);
4617                 sbi->s_overhead_last = overhead;
4618                 smp_wmb();
4619                 sbi->s_blocks_last = ext4_blocks_count(es);
4620         }
4621
4622         buf->f_type = EXT4_SUPER_MAGIC;
4623         buf->f_bsize = sb->s_blocksize;
4624         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
4625         bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
4626                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
4627         /* prevent underflow in case that few free space is available */
4628         buf->f_bfree = max_t(s64, bfree, 0);
4629         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4630         if (buf->f_bfree < ext4_r_blocks_count(es))
4631                 buf->f_bavail = 0;
4632         buf->f_files = le32_to_cpu(es->s_inodes_count);
4633         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4634         buf->f_namelen = EXT4_NAME_LEN;
4635         fsid = le64_to_cpup((void *)es->s_uuid) ^
4636                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4637         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4638         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4639
4640         return 0;
4641 }
4642
4643 /* Helper function for writing quotas on sync - we need to start transaction
4644  * before quota file is locked for write. Otherwise the are possible deadlocks:
4645  * Process 1                         Process 2
4646  * ext4_create()                     quota_sync()
4647  *   jbd2_journal_start()                  write_dquot()
4648  *   dquot_initialize()                         down(dqio_mutex)
4649  *     down(dqio_mutex)                    jbd2_journal_start()
4650  *
4651  */
4652
4653 #ifdef CONFIG_QUOTA
4654
4655 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4656 {
4657         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4658 }
4659
4660 static int ext4_write_dquot(struct dquot *dquot)
4661 {
4662         int ret, err;
4663         handle_t *handle;
4664         struct inode *inode;
4665
4666         inode = dquot_to_inode(dquot);
4667         handle = ext4_journal_start(inode,
4668                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4669         if (IS_ERR(handle))
4670                 return PTR_ERR(handle);
4671         ret = dquot_commit(dquot);
4672         err = ext4_journal_stop(handle);
4673         if (!ret)
4674                 ret = err;
4675         return ret;
4676 }
4677
4678 static int ext4_acquire_dquot(struct dquot *dquot)
4679 {
4680         int ret, err;
4681         handle_t *handle;
4682
4683         handle = ext4_journal_start(dquot_to_inode(dquot),
4684                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4685         if (IS_ERR(handle))
4686                 return PTR_ERR(handle);
4687         ret = dquot_acquire(dquot);
4688         err = ext4_journal_stop(handle);
4689         if (!ret)
4690                 ret = err;
4691         return ret;
4692 }
4693
4694 static int ext4_release_dquot(struct dquot *dquot)
4695 {
4696         int ret, err;
4697         handle_t *handle;
4698
4699         handle = ext4_journal_start(dquot_to_inode(dquot),
4700                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4701         if (IS_ERR(handle)) {
4702                 /* Release dquot anyway to avoid endless cycle in dqput() */
4703                 dquot_release(dquot);
4704                 return PTR_ERR(handle);
4705         }
4706         ret = dquot_release(dquot);
4707         err = ext4_journal_stop(handle);
4708         if (!ret)
4709                 ret = err;
4710         return ret;
4711 }
4712
4713 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4714 {
4715         /* Are we journaling quotas? */
4716         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4717             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4718                 dquot_mark_dquot_dirty(dquot);
4719                 return ext4_write_dquot(dquot);
4720         } else {
4721                 return dquot_mark_dquot_dirty(dquot);
4722         }
4723 }
4724
4725 static int ext4_write_info(struct super_block *sb, int type)
4726 {
4727         int ret, err;
4728         handle_t *handle;
4729
4730         /* Data block + inode block */
4731         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4732         if (IS_ERR(handle))
4733                 return PTR_ERR(handle);
4734         ret = dquot_commit_info(sb, type);
4735         err = ext4_journal_stop(handle);
4736         if (!ret)
4737                 ret = err;
4738         return ret;
4739 }
4740
4741 /*
4742  * Turn on quotas during mount time - we need to find
4743  * the quota file and such...
4744  */
4745 static int ext4_quota_on_mount(struct super_block *sb, int type)
4746 {
4747         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4748                                         EXT4_SB(sb)->s_jquota_fmt, type);
4749 }
4750
4751 /*
4752  * Standard function to be called on quota_on
4753  */
4754 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4755                          struct path *path)
4756 {
4757         int err;
4758
4759         if (!test_opt(sb, QUOTA))
4760                 return -EINVAL;
4761
4762         /* Quotafile not on the same filesystem? */
4763         if (path->mnt->mnt_sb != sb)
4764                 return -EXDEV;
4765         /* Journaling quota? */
4766         if (EXT4_SB(sb)->s_qf_names[type]) {
4767                 /* Quotafile not in fs root? */
4768                 if (path->dentry->d_parent != sb->s_root)
4769                         ext4_msg(sb, KERN_WARNING,
4770                                 "Quota file not on filesystem root. "
4771                                 "Journaled quota will not work");
4772         }
4773
4774         /*
4775          * When we journal data on quota file, we have to flush journal to see
4776          * all updates to the file when we bypass pagecache...
4777          */
4778         if (EXT4_SB(sb)->s_journal &&
4779             ext4_should_journal_data(path->dentry->d_inode)) {
4780                 /*
4781                  * We don't need to lock updates but journal_flush() could
4782                  * otherwise be livelocked...
4783                  */
4784                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4785                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4786                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4787                 if (err)
4788                         return err;
4789         }
4790
4791         return dquot_quota_on(sb, type, format_id, path);
4792 }
4793
4794 static int ext4_quota_off(struct super_block *sb, int type)
4795 {
4796         struct inode *inode = sb_dqopt(sb)->files[type];
4797         handle_t *handle;
4798
4799         /* Force all delayed allocation blocks to be allocated.
4800          * Caller already holds s_umount sem */
4801         if (test_opt(sb, DELALLOC))
4802                 sync_filesystem(sb);
4803
4804         if (!inode)
4805                 goto out;
4806
4807         /* Update modification times of quota files when userspace can
4808          * start looking at them */
4809         handle = ext4_journal_start(inode, 1);
4810         if (IS_ERR(handle))
4811                 goto out;
4812         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4813         ext4_mark_inode_dirty(handle, inode);
4814         ext4_journal_stop(handle);
4815
4816 out:
4817         return dquot_quota_off(sb, type);
4818 }
4819
4820 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4821  * acquiring the locks... As quota files are never truncated and quota code
4822  * itself serializes the operations (and no one else should touch the files)
4823  * we don't have to be afraid of races */
4824 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4825                                size_t len, loff_t off)
4826 {
4827         struct inode *inode = sb_dqopt(sb)->files[type];
4828         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4829         int err = 0;
4830         int offset = off & (sb->s_blocksize - 1);
4831         int tocopy;
4832         size_t toread;
4833         struct buffer_head *bh;
4834         loff_t i_size = i_size_read(inode);
4835
4836         if (off > i_size)
4837                 return 0;
4838         if (off+len > i_size)
4839                 len = i_size-off;
4840         toread = len;
4841         while (toread > 0) {
4842                 tocopy = sb->s_blocksize - offset < toread ?
4843                                 sb->s_blocksize - offset : toread;
4844                 bh = ext4_bread(NULL, inode, blk, 0, &err);
4845                 if (err)
4846                         return err;
4847                 if (!bh)        /* A hole? */
4848                         memset(data, 0, tocopy);
4849                 else
4850                         memcpy(data, bh->b_data+offset, tocopy);
4851                 brelse(bh);
4852                 offset = 0;
4853                 toread -= tocopy;
4854                 data += tocopy;
4855                 blk++;
4856         }
4857         return len;
4858 }
4859
4860 /* Write to quotafile (we know the transaction is already started and has
4861  * enough credits) */
4862 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4863                                 const char *data, size_t len, loff_t off)
4864 {
4865         struct inode *inode = sb_dqopt(sb)->files[type];
4866         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4867         int err = 0;
4868         int offset = off & (sb->s_blocksize - 1);
4869         struct buffer_head *bh;
4870         handle_t *handle = journal_current_handle();
4871
4872         if (EXT4_SB(sb)->s_journal && !handle) {
4873                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4874                         " cancelled because transaction is not started",
4875                         (unsigned long long)off, (unsigned long long)len);
4876                 return -EIO;
4877         }
4878         /*
4879          * Since we account only one data block in transaction credits,
4880          * then it is impossible to cross a block boundary.
4881          */
4882         if (sb->s_blocksize - offset < len) {
4883                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4884                         " cancelled because not block aligned",
4885                         (unsigned long long)off, (unsigned long long)len);
4886                 return -EIO;
4887         }
4888
4889         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4890         bh = ext4_bread(handle, inode, blk, 1, &err);
4891         if (!bh)
4892                 goto out;
4893         err = ext4_journal_get_write_access(handle, bh);
4894         if (err) {
4895                 brelse(bh);
4896                 goto out;
4897         }
4898         lock_buffer(bh);
4899         memcpy(bh->b_data+offset, data, len);
4900         flush_dcache_page(bh->b_page);
4901         unlock_buffer(bh);
4902         err = ext4_handle_dirty_metadata(handle, NULL, bh);
4903         brelse(bh);
4904 out:
4905         if (err) {
4906                 mutex_unlock(&inode->i_mutex);
4907                 return err;
4908         }
4909         if (inode->i_size < off + len) {
4910                 i_size_write(inode, off + len);
4911                 EXT4_I(inode)->i_disksize = inode->i_size;
4912                 ext4_mark_inode_dirty(handle, inode);
4913         }
4914         mutex_unlock(&inode->i_mutex);
4915         return len;
4916 }
4917
4918 #endif
4919
4920 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4921                        const char *dev_name, void *data)
4922 {
4923         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4924 }
4925
4926 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4927 static inline void register_as_ext2(void)
4928 {
4929         int err = register_filesystem(&ext2_fs_type);
4930         if (err)
4931                 printk(KERN_WARNING
4932                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4933 }
4934
4935 static inline void unregister_as_ext2(void)
4936 {
4937         unregister_filesystem(&ext2_fs_type);
4938 }
4939
4940 static inline int ext2_feature_set_ok(struct super_block *sb)
4941 {
4942         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
4943                 return 0;
4944         if (sb->s_flags & MS_RDONLY)
4945                 return 1;
4946         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
4947                 return 0;
4948         return 1;
4949 }
4950 MODULE_ALIAS("ext2");
4951 #else
4952 static inline void register_as_ext2(void) { }
4953 static inline void unregister_as_ext2(void) { }
4954 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
4955 #endif
4956
4957 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4958 static inline void register_as_ext3(void)
4959 {
4960         int err = register_filesystem(&ext3_fs_type);
4961         if (err)
4962                 printk(KERN_WARNING
4963                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4964 }
4965
4966 static inline void unregister_as_ext3(void)
4967 {
4968         unregister_filesystem(&ext3_fs_type);
4969 }
4970
4971 static inline int ext3_feature_set_ok(struct super_block *sb)
4972 {
4973         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
4974                 return 0;
4975         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
4976                 return 0;
4977         if (sb->s_flags & MS_RDONLY)
4978                 return 1;
4979         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
4980                 return 0;
4981         return 1;
4982 }
4983 MODULE_ALIAS("ext3");
4984 #else
4985 static inline void register_as_ext3(void) { }
4986 static inline void unregister_as_ext3(void) { }
4987 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
4988 #endif
4989
4990 static struct file_system_type ext4_fs_type = {
4991         .owner          = THIS_MODULE,
4992         .name           = "ext4",
4993         .mount          = ext4_mount,
4994         .kill_sb        = kill_block_super,
4995         .fs_flags       = FS_REQUIRES_DEV,
4996 };
4997
4998 static int __init ext4_init_feat_adverts(void)
4999 {
5000         struct ext4_features *ef;
5001         int ret = -ENOMEM;
5002
5003         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5004         if (!ef)
5005                 goto out;
5006
5007         ef->f_kobj.kset = ext4_kset;
5008         init_completion(&ef->f_kobj_unregister);
5009         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5010                                    "features");
5011         if (ret) {
5012                 kfree(ef);
5013                 goto out;
5014         }
5015
5016         ext4_feat = ef;
5017         ret = 0;
5018 out:
5019         return ret;
5020 }
5021
5022 static void ext4_exit_feat_adverts(void)
5023 {
5024         kobject_put(&ext4_feat->f_kobj);
5025         wait_for_completion(&ext4_feat->f_kobj_unregister);
5026         kfree(ext4_feat);
5027 }
5028
5029 /* Shared across all ext4 file systems */
5030 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5031 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5032
5033 static int __init ext4_init_fs(void)
5034 {
5035         int i, err;
5036
5037         ext4_check_flag_values();
5038
5039         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5040                 mutex_init(&ext4__aio_mutex[i]);
5041                 init_waitqueue_head(&ext4__ioend_wq[i]);
5042         }
5043
5044         err = ext4_init_pageio();
5045         if (err)
5046                 return err;
5047         err = ext4_init_system_zone();
5048         if (err)
5049                 goto out7;
5050         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5051         if (!ext4_kset)
5052                 goto out6;
5053         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5054         if (!ext4_proc_root)
5055                 goto out5;
5056
5057         err = ext4_init_feat_adverts();
5058         if (err)
5059                 goto out4;
5060
5061         err = ext4_init_mballoc();
5062         if (err)
5063                 goto out3;
5064
5065         err = ext4_init_xattr();
5066         if (err)
5067                 goto out2;
5068         err = init_inodecache();
5069         if (err)
5070                 goto out1;
5071         register_as_ext3();
5072         register_as_ext2();
5073         err = register_filesystem(&ext4_fs_type);
5074         if (err)
5075                 goto out;
5076
5077         ext4_li_info = NULL;
5078         mutex_init(&ext4_li_mtx);
5079         return 0;
5080 out:
5081         unregister_as_ext2();
5082         unregister_as_ext3();
5083         destroy_inodecache();
5084 out1:
5085         ext4_exit_xattr();
5086 out2:
5087         ext4_exit_mballoc();
5088 out3:
5089         ext4_exit_feat_adverts();
5090 out4:
5091         remove_proc_entry("fs/ext4", NULL);
5092 out5:
5093         kset_unregister(ext4_kset);
5094 out6:
5095         ext4_exit_system_zone();
5096 out7:
5097         ext4_exit_pageio();
5098         return err;
5099 }
5100
5101 static void __exit ext4_exit_fs(void)
5102 {
5103         ext4_destroy_lazyinit_thread();
5104         unregister_as_ext2();
5105         unregister_as_ext3();
5106         unregister_filesystem(&ext4_fs_type);
5107         destroy_inodecache();
5108         ext4_exit_xattr();
5109         ext4_exit_mballoc();
5110         ext4_exit_feat_adverts();
5111         remove_proc_entry("fs/ext4", NULL);
5112         kset_unregister(ext4_kset);
5113         ext4_exit_system_zone();
5114         ext4_exit_pageio();
5115 }
5116
5117 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5118 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5119 MODULE_LICENSE("GPL");
5120 module_init(ext4_init_fs)
5121 module_exit(ext4_exit_fs)