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1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46
47 #include "ext4.h"
48 #include "ext4_extents.h"
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64                              unsigned long journal_devnum);
65 static int ext4_commit_super(struct super_block *sb, int sync);
66 static void ext4_mark_recovery_complete(struct super_block *sb,
67                                         struct ext4_super_block *es);
68 static void ext4_clear_journal_err(struct super_block *sb,
69                                    struct ext4_super_block *es);
70 static int ext4_sync_fs(struct super_block *sb, int wait);
71 static const char *ext4_decode_error(struct super_block *sb, int errno,
72                                      char nbuf[16]);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static void ext4_write_super(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79                        const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89         .owner          = THIS_MODULE,
90         .name           = "ext2",
91         .mount          = ext4_mount,
92         .kill_sb        = kill_block_super,
93         .fs_flags       = FS_REQUIRES_DEV,
94 };
95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
96 #else
97 #define IS_EXT2_SB(sb) (0)
98 #endif
99
100
101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
102 static struct file_system_type ext3_fs_type = {
103         .owner          = THIS_MODULE,
104         .name           = "ext3",
105         .mount          = ext4_mount,
106         .kill_sb        = kill_block_super,
107         .fs_flags       = FS_REQUIRES_DEV,
108 };
109 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
110 #else
111 #define IS_EXT3_SB(sb) (0)
112 #endif
113
114 void *ext4_kvmalloc(size_t size, gfp_t flags)
115 {
116         void *ret;
117
118         ret = kmalloc(size, flags);
119         if (!ret)
120                 ret = __vmalloc(size, flags, PAGE_KERNEL);
121         return ret;
122 }
123
124 void *ext4_kvzalloc(size_t size, gfp_t flags)
125 {
126         void *ret;
127
128         ret = kzalloc(size, flags);
129         if (!ret)
130                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
131         return ret;
132 }
133
134 void ext4_kvfree(void *ptr)
135 {
136         if (is_vmalloc_addr(ptr))
137                 vfree(ptr);
138         else
139                 kfree(ptr);
140
141 }
142
143 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
144                                struct ext4_group_desc *bg)
145 {
146         return le32_to_cpu(bg->bg_block_bitmap_lo) |
147                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
148                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
149 }
150
151 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
152                                struct ext4_group_desc *bg)
153 {
154         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
155                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
156                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
157 }
158
159 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
160                               struct ext4_group_desc *bg)
161 {
162         return le32_to_cpu(bg->bg_inode_table_lo) |
163                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
164                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
165 }
166
167 __u32 ext4_free_group_clusters(struct super_block *sb,
168                                struct ext4_group_desc *bg)
169 {
170         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
171                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
172                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
173 }
174
175 __u32 ext4_free_inodes_count(struct super_block *sb,
176                               struct ext4_group_desc *bg)
177 {
178         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
179                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
180                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
181 }
182
183 __u32 ext4_used_dirs_count(struct super_block *sb,
184                               struct ext4_group_desc *bg)
185 {
186         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
187                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
188                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
189 }
190
191 __u32 ext4_itable_unused_count(struct super_block *sb,
192                               struct ext4_group_desc *bg)
193 {
194         return le16_to_cpu(bg->bg_itable_unused_lo) |
195                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
196                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
197 }
198
199 void ext4_block_bitmap_set(struct super_block *sb,
200                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
201 {
202         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
203         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
204                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
205 }
206
207 void ext4_inode_bitmap_set(struct super_block *sb,
208                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
209 {
210         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
211         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
212                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
213 }
214
215 void ext4_inode_table_set(struct super_block *sb,
216                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
217 {
218         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
219         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
220                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
221 }
222
223 void ext4_free_group_clusters_set(struct super_block *sb,
224                                   struct ext4_group_desc *bg, __u32 count)
225 {
226         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
227         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
228                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
229 }
230
231 void ext4_free_inodes_set(struct super_block *sb,
232                           struct ext4_group_desc *bg, __u32 count)
233 {
234         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
235         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
236                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
237 }
238
239 void ext4_used_dirs_set(struct super_block *sb,
240                           struct ext4_group_desc *bg, __u32 count)
241 {
242         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
243         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
244                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
245 }
246
247 void ext4_itable_unused_set(struct super_block *sb,
248                           struct ext4_group_desc *bg, __u32 count)
249 {
250         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
251         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
252                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
253 }
254
255
256 /* Just increment the non-pointer handle value */
257 static handle_t *ext4_get_nojournal(void)
258 {
259         handle_t *handle = current->journal_info;
260         unsigned long ref_cnt = (unsigned long)handle;
261
262         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
263
264         ref_cnt++;
265         handle = (handle_t *)ref_cnt;
266
267         current->journal_info = handle;
268         return handle;
269 }
270
271
272 /* Decrement the non-pointer handle value */
273 static void ext4_put_nojournal(handle_t *handle)
274 {
275         unsigned long ref_cnt = (unsigned long)handle;
276
277         BUG_ON(ref_cnt == 0);
278
279         ref_cnt--;
280         handle = (handle_t *)ref_cnt;
281
282         current->journal_info = handle;
283 }
284
285 /*
286  * Wrappers for jbd2_journal_start/end.
287  *
288  * The only special thing we need to do here is to make sure that all
289  * journal_end calls result in the superblock being marked dirty, so
290  * that sync() will call the filesystem's write_super callback if
291  * appropriate.
292  *
293  * To avoid j_barrier hold in userspace when a user calls freeze(),
294  * ext4 prevents a new handle from being started by s_frozen, which
295  * is in an upper layer.
296  */
297 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
298 {
299         journal_t *journal;
300         handle_t  *handle;
301
302         trace_ext4_journal_start(sb, nblocks, _RET_IP_);
303         if (sb->s_flags & MS_RDONLY)
304                 return ERR_PTR(-EROFS);
305
306         journal = EXT4_SB(sb)->s_journal;
307         handle = ext4_journal_current_handle();
308
309         /*
310          * If a handle has been started, it should be allowed to
311          * finish, otherwise deadlock could happen between freeze
312          * and others(e.g. truncate) due to the restart of the
313          * journal handle if the filesystem is forzen and active
314          * handles are not stopped.
315          */
316         if (!handle)
317                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
318
319         if (!journal)
320                 return ext4_get_nojournal();
321         /*
322          * Special case here: if the journal has aborted behind our
323          * backs (eg. EIO in the commit thread), then we still need to
324          * take the FS itself readonly cleanly.
325          */
326         if (is_journal_aborted(journal)) {
327                 ext4_abort(sb, "Detected aborted journal");
328                 return ERR_PTR(-EROFS);
329         }
330         return jbd2_journal_start(journal, nblocks);
331 }
332
333 /*
334  * The only special thing we need to do here is to make sure that all
335  * jbd2_journal_stop calls result in the superblock being marked dirty, so
336  * that sync() will call the filesystem's write_super callback if
337  * appropriate.
338  */
339 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
340 {
341         struct super_block *sb;
342         int err;
343         int rc;
344
345         if (!ext4_handle_valid(handle)) {
346                 ext4_put_nojournal(handle);
347                 return 0;
348         }
349         sb = handle->h_transaction->t_journal->j_private;
350         err = handle->h_err;
351         rc = jbd2_journal_stop(handle);
352
353         if (!err)
354                 err = rc;
355         if (err)
356                 __ext4_std_error(sb, where, line, err);
357         return err;
358 }
359
360 void ext4_journal_abort_handle(const char *caller, unsigned int line,
361                                const char *err_fn, struct buffer_head *bh,
362                                handle_t *handle, int err)
363 {
364         char nbuf[16];
365         const char *errstr = ext4_decode_error(NULL, err, nbuf);
366
367         BUG_ON(!ext4_handle_valid(handle));
368
369         if (bh)
370                 BUFFER_TRACE(bh, "abort");
371
372         if (!handle->h_err)
373                 handle->h_err = err;
374
375         if (is_handle_aborted(handle))
376                 return;
377
378         printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
379                caller, line, errstr, err_fn);
380
381         jbd2_journal_abort_handle(handle);
382 }
383
384 static void __save_error_info(struct super_block *sb, const char *func,
385                             unsigned int line)
386 {
387         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
388
389         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
390         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
391         es->s_last_error_time = cpu_to_le32(get_seconds());
392         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
393         es->s_last_error_line = cpu_to_le32(line);
394         if (!es->s_first_error_time) {
395                 es->s_first_error_time = es->s_last_error_time;
396                 strncpy(es->s_first_error_func, func,
397                         sizeof(es->s_first_error_func));
398                 es->s_first_error_line = cpu_to_le32(line);
399                 es->s_first_error_ino = es->s_last_error_ino;
400                 es->s_first_error_block = es->s_last_error_block;
401         }
402         /*
403          * Start the daily error reporting function if it hasn't been
404          * started already
405          */
406         if (!es->s_error_count)
407                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
408         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
409 }
410
411 static void save_error_info(struct super_block *sb, const char *func,
412                             unsigned int line)
413 {
414         __save_error_info(sb, func, line);
415         ext4_commit_super(sb, 1);
416 }
417
418 /*
419  * The del_gendisk() function uninitializes the disk-specific data
420  * structures, including the bdi structure, without telling anyone
421  * else.  Once this happens, any attempt to call mark_buffer_dirty()
422  * (for example, by ext4_commit_super), will cause a kernel OOPS.
423  * This is a kludge to prevent these oops until we can put in a proper
424  * hook in del_gendisk() to inform the VFS and file system layers.
425  */
426 static int block_device_ejected(struct super_block *sb)
427 {
428         struct inode *bd_inode = sb->s_bdev->bd_inode;
429         struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
430
431         return bdi->dev == NULL;
432 }
433
434
435 /* Deal with the reporting of failure conditions on a filesystem such as
436  * inconsistencies detected or read IO failures.
437  *
438  * On ext2, we can store the error state of the filesystem in the
439  * superblock.  That is not possible on ext4, because we may have other
440  * write ordering constraints on the superblock which prevent us from
441  * writing it out straight away; and given that the journal is about to
442  * be aborted, we can't rely on the current, or future, transactions to
443  * write out the superblock safely.
444  *
445  * We'll just use the jbd2_journal_abort() error code to record an error in
446  * the journal instead.  On recovery, the journal will complain about
447  * that error until we've noted it down and cleared it.
448  */
449
450 static void ext4_handle_error(struct super_block *sb)
451 {
452         if (sb->s_flags & MS_RDONLY)
453                 return;
454
455         if (!test_opt(sb, ERRORS_CONT)) {
456                 journal_t *journal = EXT4_SB(sb)->s_journal;
457
458                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
459                 if (journal)
460                         jbd2_journal_abort(journal, -EIO);
461         }
462         if (test_opt(sb, ERRORS_RO)) {
463                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
464                 sb->s_flags |= MS_RDONLY;
465         }
466         if (test_opt(sb, ERRORS_PANIC))
467                 panic("EXT4-fs (device %s): panic forced after error\n",
468                         sb->s_id);
469 }
470
471 void __ext4_error(struct super_block *sb, const char *function,
472                   unsigned int line, const char *fmt, ...)
473 {
474         struct va_format vaf;
475         va_list args;
476
477         va_start(args, fmt);
478         vaf.fmt = fmt;
479         vaf.va = &args;
480         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
481                sb->s_id, function, line, current->comm, &vaf);
482         va_end(args);
483
484         ext4_handle_error(sb);
485 }
486
487 void ext4_error_inode(struct inode *inode, const char *function,
488                       unsigned int line, ext4_fsblk_t block,
489                       const char *fmt, ...)
490 {
491         va_list args;
492         struct va_format vaf;
493         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
494
495         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
496         es->s_last_error_block = cpu_to_le64(block);
497         save_error_info(inode->i_sb, function, line);
498         va_start(args, fmt);
499         vaf.fmt = fmt;
500         vaf.va = &args;
501         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
502                inode->i_sb->s_id, function, line, inode->i_ino);
503         if (block)
504                 printk(KERN_CONT "block %llu: ", block);
505         printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
506         va_end(args);
507
508         ext4_handle_error(inode->i_sb);
509 }
510
511 void ext4_error_file(struct file *file, const char *function,
512                      unsigned int line, ext4_fsblk_t block,
513                      const char *fmt, ...)
514 {
515         va_list args;
516         struct va_format vaf;
517         struct ext4_super_block *es;
518         struct inode *inode = file->f_dentry->d_inode;
519         char pathname[80], *path;
520
521         es = EXT4_SB(inode->i_sb)->s_es;
522         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
523         save_error_info(inode->i_sb, function, line);
524         path = d_path(&(file->f_path), pathname, sizeof(pathname));
525         if (IS_ERR(path))
526                 path = "(unknown)";
527         printk(KERN_CRIT
528                "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
529                inode->i_sb->s_id, function, line, inode->i_ino);
530         if (block)
531                 printk(KERN_CONT "block %llu: ", block);
532         va_start(args, fmt);
533         vaf.fmt = fmt;
534         vaf.va = &args;
535         printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
536         va_end(args);
537
538         ext4_handle_error(inode->i_sb);
539 }
540
541 static const char *ext4_decode_error(struct super_block *sb, int errno,
542                                      char nbuf[16])
543 {
544         char *errstr = NULL;
545
546         switch (errno) {
547         case -EIO:
548                 errstr = "IO failure";
549                 break;
550         case -ENOMEM:
551                 errstr = "Out of memory";
552                 break;
553         case -EROFS:
554                 if (!sb || (EXT4_SB(sb)->s_journal &&
555                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
556                         errstr = "Journal has aborted";
557                 else
558                         errstr = "Readonly filesystem";
559                 break;
560         default:
561                 /* If the caller passed in an extra buffer for unknown
562                  * errors, textualise them now.  Else we just return
563                  * NULL. */
564                 if (nbuf) {
565                         /* Check for truncated error codes... */
566                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
567                                 errstr = nbuf;
568                 }
569                 break;
570         }
571
572         return errstr;
573 }
574
575 /* __ext4_std_error decodes expected errors from journaling functions
576  * automatically and invokes the appropriate error response.  */
577
578 void __ext4_std_error(struct super_block *sb, const char *function,
579                       unsigned int line, int errno)
580 {
581         char nbuf[16];
582         const char *errstr;
583
584         /* Special case: if the error is EROFS, and we're not already
585          * inside a transaction, then there's really no point in logging
586          * an error. */
587         if (errno == -EROFS && journal_current_handle() == NULL &&
588             (sb->s_flags & MS_RDONLY))
589                 return;
590
591         errstr = ext4_decode_error(sb, errno, nbuf);
592         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
593                sb->s_id, function, line, errstr);
594         save_error_info(sb, function, line);
595
596         ext4_handle_error(sb);
597 }
598
599 /*
600  * ext4_abort is a much stronger failure handler than ext4_error.  The
601  * abort function may be used to deal with unrecoverable failures such
602  * as journal IO errors or ENOMEM at a critical moment in log management.
603  *
604  * We unconditionally force the filesystem into an ABORT|READONLY state,
605  * unless the error response on the fs has been set to panic in which
606  * case we take the easy way out and panic immediately.
607  */
608
609 void __ext4_abort(struct super_block *sb, const char *function,
610                 unsigned int line, const char *fmt, ...)
611 {
612         va_list args;
613
614         save_error_info(sb, function, line);
615         va_start(args, fmt);
616         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
617                function, line);
618         vprintk(fmt, args);
619         printk("\n");
620         va_end(args);
621
622         if ((sb->s_flags & MS_RDONLY) == 0) {
623                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
624                 sb->s_flags |= MS_RDONLY;
625                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
626                 if (EXT4_SB(sb)->s_journal)
627                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
628                 save_error_info(sb, function, line);
629         }
630         if (test_opt(sb, ERRORS_PANIC))
631                 panic("EXT4-fs panic from previous error\n");
632 }
633
634 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
635 {
636         struct va_format vaf;
637         va_list args;
638
639         va_start(args, fmt);
640         vaf.fmt = fmt;
641         vaf.va = &args;
642         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
643         va_end(args);
644 }
645
646 void __ext4_warning(struct super_block *sb, const char *function,
647                     unsigned int line, const char *fmt, ...)
648 {
649         struct va_format vaf;
650         va_list args;
651
652         va_start(args, fmt);
653         vaf.fmt = fmt;
654         vaf.va = &args;
655         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
656                sb->s_id, function, line, &vaf);
657         va_end(args);
658 }
659
660 void __ext4_grp_locked_error(const char *function, unsigned int line,
661                              struct super_block *sb, ext4_group_t grp,
662                              unsigned long ino, ext4_fsblk_t block,
663                              const char *fmt, ...)
664 __releases(bitlock)
665 __acquires(bitlock)
666 {
667         struct va_format vaf;
668         va_list args;
669         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
670
671         es->s_last_error_ino = cpu_to_le32(ino);
672         es->s_last_error_block = cpu_to_le64(block);
673         __save_error_info(sb, function, line);
674
675         va_start(args, fmt);
676
677         vaf.fmt = fmt;
678         vaf.va = &args;
679         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
680                sb->s_id, function, line, grp);
681         if (ino)
682                 printk(KERN_CONT "inode %lu: ", ino);
683         if (block)
684                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
685         printk(KERN_CONT "%pV\n", &vaf);
686         va_end(args);
687
688         if (test_opt(sb, ERRORS_CONT)) {
689                 ext4_commit_super(sb, 0);
690                 return;
691         }
692
693         ext4_unlock_group(sb, grp);
694         ext4_handle_error(sb);
695         /*
696          * We only get here in the ERRORS_RO case; relocking the group
697          * may be dangerous, but nothing bad will happen since the
698          * filesystem will have already been marked read/only and the
699          * journal has been aborted.  We return 1 as a hint to callers
700          * who might what to use the return value from
701          * ext4_grp_locked_error() to distinguish between the
702          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
703          * aggressively from the ext4 function in question, with a
704          * more appropriate error code.
705          */
706         ext4_lock_group(sb, grp);
707         return;
708 }
709
710 void ext4_update_dynamic_rev(struct super_block *sb)
711 {
712         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
713
714         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
715                 return;
716
717         ext4_warning(sb,
718                      "updating to rev %d because of new feature flag, "
719                      "running e2fsck is recommended",
720                      EXT4_DYNAMIC_REV);
721
722         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
723         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
724         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
725         /* leave es->s_feature_*compat flags alone */
726         /* es->s_uuid will be set by e2fsck if empty */
727
728         /*
729          * The rest of the superblock fields should be zero, and if not it
730          * means they are likely already in use, so leave them alone.  We
731          * can leave it up to e2fsck to clean up any inconsistencies there.
732          */
733 }
734
735 /*
736  * Open the external journal device
737  */
738 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
739 {
740         struct block_device *bdev;
741         char b[BDEVNAME_SIZE];
742
743         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
744         if (IS_ERR(bdev))
745                 goto fail;
746         return bdev;
747
748 fail:
749         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
750                         __bdevname(dev, b), PTR_ERR(bdev));
751         return NULL;
752 }
753
754 /*
755  * Release the journal device
756  */
757 static int ext4_blkdev_put(struct block_device *bdev)
758 {
759         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
760 }
761
762 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
763 {
764         struct block_device *bdev;
765         int ret = -ENODEV;
766
767         bdev = sbi->journal_bdev;
768         if (bdev) {
769                 ret = ext4_blkdev_put(bdev);
770                 sbi->journal_bdev = NULL;
771         }
772         return ret;
773 }
774
775 static inline struct inode *orphan_list_entry(struct list_head *l)
776 {
777         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
778 }
779
780 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
781 {
782         struct list_head *l;
783
784         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
785                  le32_to_cpu(sbi->s_es->s_last_orphan));
786
787         printk(KERN_ERR "sb_info orphan list:\n");
788         list_for_each(l, &sbi->s_orphan) {
789                 struct inode *inode = orphan_list_entry(l);
790                 printk(KERN_ERR "  "
791                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
792                        inode->i_sb->s_id, inode->i_ino, inode,
793                        inode->i_mode, inode->i_nlink,
794                        NEXT_ORPHAN(inode));
795         }
796 }
797
798 static void ext4_put_super(struct super_block *sb)
799 {
800         struct ext4_sb_info *sbi = EXT4_SB(sb);
801         struct ext4_super_block *es = sbi->s_es;
802         int i, err;
803
804         ext4_unregister_li_request(sb);
805         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
806
807         flush_workqueue(sbi->dio_unwritten_wq);
808         destroy_workqueue(sbi->dio_unwritten_wq);
809
810         lock_super(sb);
811         if (sb->s_dirt)
812                 ext4_commit_super(sb, 1);
813
814         if (sbi->s_journal) {
815                 err = jbd2_journal_destroy(sbi->s_journal);
816                 sbi->s_journal = NULL;
817                 if (err < 0)
818                         ext4_abort(sb, "Couldn't clean up the journal");
819         }
820
821         del_timer(&sbi->s_err_report);
822         ext4_release_system_zone(sb);
823         ext4_mb_release(sb);
824         ext4_ext_release(sb);
825         ext4_xattr_put_super(sb);
826
827         if (!(sb->s_flags & MS_RDONLY)) {
828                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
829                 es->s_state = cpu_to_le16(sbi->s_mount_state);
830                 ext4_commit_super(sb, 1);
831         }
832         if (sbi->s_proc) {
833                 remove_proc_entry(sb->s_id, ext4_proc_root);
834         }
835         kobject_del(&sbi->s_kobj);
836
837         for (i = 0; i < sbi->s_gdb_count; i++)
838                 brelse(sbi->s_group_desc[i]);
839         ext4_kvfree(sbi->s_group_desc);
840         ext4_kvfree(sbi->s_flex_groups);
841         percpu_counter_destroy(&sbi->s_freeclusters_counter);
842         percpu_counter_destroy(&sbi->s_freeinodes_counter);
843         percpu_counter_destroy(&sbi->s_dirs_counter);
844         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
845         brelse(sbi->s_sbh);
846 #ifdef CONFIG_QUOTA
847         for (i = 0; i < MAXQUOTAS; i++)
848                 kfree(sbi->s_qf_names[i]);
849 #endif
850
851         /* Debugging code just in case the in-memory inode orphan list
852          * isn't empty.  The on-disk one can be non-empty if we've
853          * detected an error and taken the fs readonly, but the
854          * in-memory list had better be clean by this point. */
855         if (!list_empty(&sbi->s_orphan))
856                 dump_orphan_list(sb, sbi);
857         J_ASSERT(list_empty(&sbi->s_orphan));
858
859         invalidate_bdev(sb->s_bdev);
860         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
861                 /*
862                  * Invalidate the journal device's buffers.  We don't want them
863                  * floating about in memory - the physical journal device may
864                  * hotswapped, and it breaks the `ro-after' testing code.
865                  */
866                 sync_blockdev(sbi->journal_bdev);
867                 invalidate_bdev(sbi->journal_bdev);
868                 ext4_blkdev_remove(sbi);
869         }
870         if (sbi->s_mmp_tsk)
871                 kthread_stop(sbi->s_mmp_tsk);
872         sb->s_fs_info = NULL;
873         /*
874          * Now that we are completely done shutting down the
875          * superblock, we need to actually destroy the kobject.
876          */
877         unlock_super(sb);
878         kobject_put(&sbi->s_kobj);
879         wait_for_completion(&sbi->s_kobj_unregister);
880         kfree(sbi->s_blockgroup_lock);
881         kfree(sbi);
882 }
883
884 static struct kmem_cache *ext4_inode_cachep;
885
886 /*
887  * Called inside transaction, so use GFP_NOFS
888  */
889 static struct inode *ext4_alloc_inode(struct super_block *sb)
890 {
891         struct ext4_inode_info *ei;
892
893         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
894         if (!ei)
895                 return NULL;
896
897         ei->vfs_inode.i_version = 1;
898         ei->vfs_inode.i_data.writeback_index = 0;
899         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
900         INIT_LIST_HEAD(&ei->i_prealloc_list);
901         spin_lock_init(&ei->i_prealloc_lock);
902         ei->i_reserved_data_blocks = 0;
903         ei->i_reserved_meta_blocks = 0;
904         ei->i_allocated_meta_blocks = 0;
905         ei->i_da_metadata_calc_len = 0;
906         spin_lock_init(&(ei->i_block_reservation_lock));
907 #ifdef CONFIG_QUOTA
908         ei->i_reserved_quota = 0;
909 #endif
910         ei->jinode = NULL;
911         INIT_LIST_HEAD(&ei->i_completed_io_list);
912         spin_lock_init(&ei->i_completed_io_lock);
913         ei->cur_aio_dio = NULL;
914         ei->i_sync_tid = 0;
915         ei->i_datasync_tid = 0;
916         atomic_set(&ei->i_ioend_count, 0);
917         atomic_set(&ei->i_aiodio_unwritten, 0);
918
919         return &ei->vfs_inode;
920 }
921
922 static int ext4_drop_inode(struct inode *inode)
923 {
924         int drop = generic_drop_inode(inode);
925
926         trace_ext4_drop_inode(inode, drop);
927         return drop;
928 }
929
930 static void ext4_i_callback(struct rcu_head *head)
931 {
932         struct inode *inode = container_of(head, struct inode, i_rcu);
933         INIT_LIST_HEAD(&inode->i_dentry);
934         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
935 }
936
937 static void ext4_destroy_inode(struct inode *inode)
938 {
939         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
940                 ext4_msg(inode->i_sb, KERN_ERR,
941                          "Inode %lu (%p): orphan list check failed!",
942                          inode->i_ino, EXT4_I(inode));
943                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
944                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
945                                 true);
946                 dump_stack();
947         }
948         call_rcu(&inode->i_rcu, ext4_i_callback);
949 }
950
951 static void init_once(void *foo)
952 {
953         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
954
955         INIT_LIST_HEAD(&ei->i_orphan);
956 #ifdef CONFIG_EXT4_FS_XATTR
957         init_rwsem(&ei->xattr_sem);
958 #endif
959         init_rwsem(&ei->i_data_sem);
960         inode_init_once(&ei->vfs_inode);
961 }
962
963 static int init_inodecache(void)
964 {
965         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
966                                              sizeof(struct ext4_inode_info),
967                                              0, (SLAB_RECLAIM_ACCOUNT|
968                                                 SLAB_MEM_SPREAD),
969                                              init_once);
970         if (ext4_inode_cachep == NULL)
971                 return -ENOMEM;
972         return 0;
973 }
974
975 static void destroy_inodecache(void)
976 {
977         kmem_cache_destroy(ext4_inode_cachep);
978 }
979
980 void ext4_clear_inode(struct inode *inode)
981 {
982         invalidate_inode_buffers(inode);
983         end_writeback(inode);
984         dquot_drop(inode);
985         ext4_discard_preallocations(inode);
986         if (EXT4_I(inode)->jinode) {
987                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
988                                                EXT4_I(inode)->jinode);
989                 jbd2_free_inode(EXT4_I(inode)->jinode);
990                 EXT4_I(inode)->jinode = NULL;
991         }
992 }
993
994 static inline void ext4_show_quota_options(struct seq_file *seq,
995                                            struct super_block *sb)
996 {
997 #if defined(CONFIG_QUOTA)
998         struct ext4_sb_info *sbi = EXT4_SB(sb);
999
1000         if (sbi->s_jquota_fmt) {
1001                 char *fmtname = "";
1002
1003                 switch (sbi->s_jquota_fmt) {
1004                 case QFMT_VFS_OLD:
1005                         fmtname = "vfsold";
1006                         break;
1007                 case QFMT_VFS_V0:
1008                         fmtname = "vfsv0";
1009                         break;
1010                 case QFMT_VFS_V1:
1011                         fmtname = "vfsv1";
1012                         break;
1013                 }
1014                 seq_printf(seq, ",jqfmt=%s", fmtname);
1015         }
1016
1017         if (sbi->s_qf_names[USRQUOTA])
1018                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1019
1020         if (sbi->s_qf_names[GRPQUOTA])
1021                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1022
1023         if (test_opt(sb, USRQUOTA))
1024                 seq_puts(seq, ",usrquota");
1025
1026         if (test_opt(sb, GRPQUOTA))
1027                 seq_puts(seq, ",grpquota");
1028 #endif
1029 }
1030
1031 /*
1032  * Show an option if
1033  *  - it's set to a non-default value OR
1034  *  - if the per-sb default is different from the global default
1035  */
1036 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
1037 {
1038         int def_errors;
1039         unsigned long def_mount_opts;
1040         struct super_block *sb = vfs->mnt_sb;
1041         struct ext4_sb_info *sbi = EXT4_SB(sb);
1042         struct ext4_super_block *es = sbi->s_es;
1043
1044         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1045         def_errors     = le16_to_cpu(es->s_errors);
1046
1047         if (sbi->s_sb_block != 1)
1048                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
1049         if (test_opt(sb, MINIX_DF))
1050                 seq_puts(seq, ",minixdf");
1051         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
1052                 seq_puts(seq, ",grpid");
1053         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
1054                 seq_puts(seq, ",nogrpid");
1055         if (sbi->s_resuid != EXT4_DEF_RESUID ||
1056             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
1057                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
1058         }
1059         if (sbi->s_resgid != EXT4_DEF_RESGID ||
1060             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
1061                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
1062         }
1063         if (test_opt(sb, ERRORS_RO)) {
1064                 if (def_errors == EXT4_ERRORS_PANIC ||
1065                     def_errors == EXT4_ERRORS_CONTINUE) {
1066                         seq_puts(seq, ",errors=remount-ro");
1067                 }
1068         }
1069         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1070                 seq_puts(seq, ",errors=continue");
1071         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1072                 seq_puts(seq, ",errors=panic");
1073         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
1074                 seq_puts(seq, ",nouid32");
1075         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
1076                 seq_puts(seq, ",debug");
1077 #ifdef CONFIG_EXT4_FS_XATTR
1078         if (test_opt(sb, XATTR_USER))
1079                 seq_puts(seq, ",user_xattr");
1080         if (!test_opt(sb, XATTR_USER))
1081                 seq_puts(seq, ",nouser_xattr");
1082 #endif
1083 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1084         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1085                 seq_puts(seq, ",acl");
1086         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1087                 seq_puts(seq, ",noacl");
1088 #endif
1089         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1090                 seq_printf(seq, ",commit=%u",
1091                            (unsigned) (sbi->s_commit_interval / HZ));
1092         }
1093         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1094                 seq_printf(seq, ",min_batch_time=%u",
1095                            (unsigned) sbi->s_min_batch_time);
1096         }
1097         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1098                 seq_printf(seq, ",max_batch_time=%u",
1099                            (unsigned) sbi->s_min_batch_time);
1100         }
1101
1102         /*
1103          * We're changing the default of barrier mount option, so
1104          * let's always display its mount state so it's clear what its
1105          * status is.
1106          */
1107         seq_puts(seq, ",barrier=");
1108         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1109         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1110                 seq_puts(seq, ",journal_async_commit");
1111         else if (test_opt(sb, JOURNAL_CHECKSUM))
1112                 seq_puts(seq, ",journal_checksum");
1113         if (test_opt(sb, I_VERSION))
1114                 seq_puts(seq, ",i_version");
1115         if (!test_opt(sb, DELALLOC) &&
1116             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1117                 seq_puts(seq, ",nodelalloc");
1118
1119         if (!test_opt(sb, MBLK_IO_SUBMIT))
1120                 seq_puts(seq, ",nomblk_io_submit");
1121         if (sbi->s_stripe)
1122                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1123         /*
1124          * journal mode get enabled in different ways
1125          * So just print the value even if we didn't specify it
1126          */
1127         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1128                 seq_puts(seq, ",data=journal");
1129         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1130                 seq_puts(seq, ",data=ordered");
1131         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1132                 seq_puts(seq, ",data=writeback");
1133
1134         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1135                 seq_printf(seq, ",inode_readahead_blks=%u",
1136                            sbi->s_inode_readahead_blks);
1137
1138         if (test_opt(sb, DATA_ERR_ABORT))
1139                 seq_puts(seq, ",data_err=abort");
1140
1141         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1142                 seq_puts(seq, ",noauto_da_alloc");
1143
1144         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1145                 seq_puts(seq, ",discard");
1146
1147         if (test_opt(sb, NOLOAD))
1148                 seq_puts(seq, ",norecovery");
1149
1150         if (test_opt(sb, DIOREAD_NOLOCK))
1151                 seq_puts(seq, ",dioread_nolock");
1152
1153         if (test_opt(sb, BLOCK_VALIDITY) &&
1154             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1155                 seq_puts(seq, ",block_validity");
1156
1157         if (!test_opt(sb, INIT_INODE_TABLE))
1158                 seq_puts(seq, ",noinit_itable");
1159         else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
1160                 seq_printf(seq, ",init_itable=%u",
1161                            (unsigned) sbi->s_li_wait_mult);
1162
1163         ext4_show_quota_options(seq, sb);
1164
1165         return 0;
1166 }
1167
1168 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1169                                         u64 ino, u32 generation)
1170 {
1171         struct inode *inode;
1172
1173         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1174                 return ERR_PTR(-ESTALE);
1175         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1176                 return ERR_PTR(-ESTALE);
1177
1178         /* iget isn't really right if the inode is currently unallocated!!
1179          *
1180          * ext4_read_inode will return a bad_inode if the inode had been
1181          * deleted, so we should be safe.
1182          *
1183          * Currently we don't know the generation for parent directory, so
1184          * a generation of 0 means "accept any"
1185          */
1186         inode = ext4_iget(sb, ino);
1187         if (IS_ERR(inode))
1188                 return ERR_CAST(inode);
1189         if (generation && inode->i_generation != generation) {
1190                 iput(inode);
1191                 return ERR_PTR(-ESTALE);
1192         }
1193
1194         return inode;
1195 }
1196
1197 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1198                                         int fh_len, int fh_type)
1199 {
1200         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1201                                     ext4_nfs_get_inode);
1202 }
1203
1204 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1205                                         int fh_len, int fh_type)
1206 {
1207         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1208                                     ext4_nfs_get_inode);
1209 }
1210
1211 /*
1212  * Try to release metadata pages (indirect blocks, directories) which are
1213  * mapped via the block device.  Since these pages could have journal heads
1214  * which would prevent try_to_free_buffers() from freeing them, we must use
1215  * jbd2 layer's try_to_free_buffers() function to release them.
1216  */
1217 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1218                                  gfp_t wait)
1219 {
1220         journal_t *journal = EXT4_SB(sb)->s_journal;
1221
1222         WARN_ON(PageChecked(page));
1223         if (!page_has_buffers(page))
1224                 return 0;
1225         if (journal)
1226                 return jbd2_journal_try_to_free_buffers(journal, page,
1227                                                         wait & ~__GFP_WAIT);
1228         return try_to_free_buffers(page);
1229 }
1230
1231 #ifdef CONFIG_QUOTA
1232 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1233 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1234
1235 static int ext4_write_dquot(struct dquot *dquot);
1236 static int ext4_acquire_dquot(struct dquot *dquot);
1237 static int ext4_release_dquot(struct dquot *dquot);
1238 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1239 static int ext4_write_info(struct super_block *sb, int type);
1240 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1241                          struct path *path);
1242 static int ext4_quota_off(struct super_block *sb, int type);
1243 static int ext4_quota_on_mount(struct super_block *sb, int type);
1244 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1245                                size_t len, loff_t off);
1246 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1247                                 const char *data, size_t len, loff_t off);
1248
1249 static const struct dquot_operations ext4_quota_operations = {
1250         .get_reserved_space = ext4_get_reserved_space,
1251         .write_dquot    = ext4_write_dquot,
1252         .acquire_dquot  = ext4_acquire_dquot,
1253         .release_dquot  = ext4_release_dquot,
1254         .mark_dirty     = ext4_mark_dquot_dirty,
1255         .write_info     = ext4_write_info,
1256         .alloc_dquot    = dquot_alloc,
1257         .destroy_dquot  = dquot_destroy,
1258 };
1259
1260 static const struct quotactl_ops ext4_qctl_operations = {
1261         .quota_on       = ext4_quota_on,
1262         .quota_off      = ext4_quota_off,
1263         .quota_sync     = dquot_quota_sync,
1264         .get_info       = dquot_get_dqinfo,
1265         .set_info       = dquot_set_dqinfo,
1266         .get_dqblk      = dquot_get_dqblk,
1267         .set_dqblk      = dquot_set_dqblk
1268 };
1269 #endif
1270
1271 static const struct super_operations ext4_sops = {
1272         .alloc_inode    = ext4_alloc_inode,
1273         .destroy_inode  = ext4_destroy_inode,
1274         .write_inode    = ext4_write_inode,
1275         .dirty_inode    = ext4_dirty_inode,
1276         .drop_inode     = ext4_drop_inode,
1277         .evict_inode    = ext4_evict_inode,
1278         .put_super      = ext4_put_super,
1279         .sync_fs        = ext4_sync_fs,
1280         .freeze_fs      = ext4_freeze,
1281         .unfreeze_fs    = ext4_unfreeze,
1282         .statfs         = ext4_statfs,
1283         .remount_fs     = ext4_remount,
1284         .show_options   = ext4_show_options,
1285 #ifdef CONFIG_QUOTA
1286         .quota_read     = ext4_quota_read,
1287         .quota_write    = ext4_quota_write,
1288 #endif
1289         .bdev_try_to_free_page = bdev_try_to_free_page,
1290 };
1291
1292 static const struct super_operations ext4_nojournal_sops = {
1293         .alloc_inode    = ext4_alloc_inode,
1294         .destroy_inode  = ext4_destroy_inode,
1295         .write_inode    = ext4_write_inode,
1296         .dirty_inode    = ext4_dirty_inode,
1297         .drop_inode     = ext4_drop_inode,
1298         .evict_inode    = ext4_evict_inode,
1299         .write_super    = ext4_write_super,
1300         .put_super      = ext4_put_super,
1301         .statfs         = ext4_statfs,
1302         .remount_fs     = ext4_remount,
1303         .show_options   = ext4_show_options,
1304 #ifdef CONFIG_QUOTA
1305         .quota_read     = ext4_quota_read,
1306         .quota_write    = ext4_quota_write,
1307 #endif
1308         .bdev_try_to_free_page = bdev_try_to_free_page,
1309 };
1310
1311 static const struct export_operations ext4_export_ops = {
1312         .fh_to_dentry = ext4_fh_to_dentry,
1313         .fh_to_parent = ext4_fh_to_parent,
1314         .get_parent = ext4_get_parent,
1315 };
1316
1317 enum {
1318         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1319         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1320         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1321         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1322         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1323         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1324         Opt_journal_update, Opt_journal_dev,
1325         Opt_journal_checksum, Opt_journal_async_commit,
1326         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1327         Opt_data_err_abort, Opt_data_err_ignore,
1328         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1329         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1330         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1331         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1332         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1333         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1334         Opt_inode_readahead_blks, Opt_journal_ioprio,
1335         Opt_dioread_nolock, Opt_dioread_lock,
1336         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1337 };
1338
1339 static const match_table_t tokens = {
1340         {Opt_bsd_df, "bsddf"},
1341         {Opt_minix_df, "minixdf"},
1342         {Opt_grpid, "grpid"},
1343         {Opt_grpid, "bsdgroups"},
1344         {Opt_nogrpid, "nogrpid"},
1345         {Opt_nogrpid, "sysvgroups"},
1346         {Opt_resgid, "resgid=%u"},
1347         {Opt_resuid, "resuid=%u"},
1348         {Opt_sb, "sb=%u"},
1349         {Opt_err_cont, "errors=continue"},
1350         {Opt_err_panic, "errors=panic"},
1351         {Opt_err_ro, "errors=remount-ro"},
1352         {Opt_nouid32, "nouid32"},
1353         {Opt_debug, "debug"},
1354         {Opt_oldalloc, "oldalloc"},
1355         {Opt_orlov, "orlov"},
1356         {Opt_user_xattr, "user_xattr"},
1357         {Opt_nouser_xattr, "nouser_xattr"},
1358         {Opt_acl, "acl"},
1359         {Opt_noacl, "noacl"},
1360         {Opt_noload, "noload"},
1361         {Opt_noload, "norecovery"},
1362         {Opt_nobh, "nobh"},
1363         {Opt_bh, "bh"},
1364         {Opt_commit, "commit=%u"},
1365         {Opt_min_batch_time, "min_batch_time=%u"},
1366         {Opt_max_batch_time, "max_batch_time=%u"},
1367         {Opt_journal_update, "journal=update"},
1368         {Opt_journal_dev, "journal_dev=%u"},
1369         {Opt_journal_checksum, "journal_checksum"},
1370         {Opt_journal_async_commit, "journal_async_commit"},
1371         {Opt_abort, "abort"},
1372         {Opt_data_journal, "data=journal"},
1373         {Opt_data_ordered, "data=ordered"},
1374         {Opt_data_writeback, "data=writeback"},
1375         {Opt_data_err_abort, "data_err=abort"},
1376         {Opt_data_err_ignore, "data_err=ignore"},
1377         {Opt_offusrjquota, "usrjquota="},
1378         {Opt_usrjquota, "usrjquota=%s"},
1379         {Opt_offgrpjquota, "grpjquota="},
1380         {Opt_grpjquota, "grpjquota=%s"},
1381         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1382         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1383         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1384         {Opt_grpquota, "grpquota"},
1385         {Opt_noquota, "noquota"},
1386         {Opt_quota, "quota"},
1387         {Opt_usrquota, "usrquota"},
1388         {Opt_barrier, "barrier=%u"},
1389         {Opt_barrier, "barrier"},
1390         {Opt_nobarrier, "nobarrier"},
1391         {Opt_i_version, "i_version"},
1392         {Opt_stripe, "stripe=%u"},
1393         {Opt_resize, "resize"},
1394         {Opt_delalloc, "delalloc"},
1395         {Opt_nodelalloc, "nodelalloc"},
1396         {Opt_mblk_io_submit, "mblk_io_submit"},
1397         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1398         {Opt_block_validity, "block_validity"},
1399         {Opt_noblock_validity, "noblock_validity"},
1400         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1401         {Opt_journal_ioprio, "journal_ioprio=%u"},
1402         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1403         {Opt_auto_da_alloc, "auto_da_alloc"},
1404         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1405         {Opt_dioread_nolock, "dioread_nolock"},
1406         {Opt_dioread_lock, "dioread_lock"},
1407         {Opt_discard, "discard"},
1408         {Opt_nodiscard, "nodiscard"},
1409         {Opt_init_itable, "init_itable=%u"},
1410         {Opt_init_itable, "init_itable"},
1411         {Opt_noinit_itable, "noinit_itable"},
1412         {Opt_err, NULL},
1413 };
1414
1415 static ext4_fsblk_t get_sb_block(void **data)
1416 {
1417         ext4_fsblk_t    sb_block;
1418         char            *options = (char *) *data;
1419
1420         if (!options || strncmp(options, "sb=", 3) != 0)
1421                 return 1;       /* Default location */
1422
1423         options += 3;
1424         /* TODO: use simple_strtoll with >32bit ext4 */
1425         sb_block = simple_strtoul(options, &options, 0);
1426         if (*options && *options != ',') {
1427                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1428                        (char *) *data);
1429                 return 1;
1430         }
1431         if (*options == ',')
1432                 options++;
1433         *data = (void *) options;
1434
1435         return sb_block;
1436 }
1437
1438 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1439 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1440         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1441
1442 #ifdef CONFIG_QUOTA
1443 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1444 {
1445         struct ext4_sb_info *sbi = EXT4_SB(sb);
1446         char *qname;
1447
1448         if (sb_any_quota_loaded(sb) &&
1449                 !sbi->s_qf_names[qtype]) {
1450                 ext4_msg(sb, KERN_ERR,
1451                         "Cannot change journaled "
1452                         "quota options when quota turned on");
1453                 return 0;
1454         }
1455         qname = match_strdup(args);
1456         if (!qname) {
1457                 ext4_msg(sb, KERN_ERR,
1458                         "Not enough memory for storing quotafile name");
1459                 return 0;
1460         }
1461         if (sbi->s_qf_names[qtype] &&
1462                 strcmp(sbi->s_qf_names[qtype], qname)) {
1463                 ext4_msg(sb, KERN_ERR,
1464                         "%s quota file already specified", QTYPE2NAME(qtype));
1465                 kfree(qname);
1466                 return 0;
1467         }
1468         sbi->s_qf_names[qtype] = qname;
1469         if (strchr(sbi->s_qf_names[qtype], '/')) {
1470                 ext4_msg(sb, KERN_ERR,
1471                         "quotafile must be on filesystem root");
1472                 kfree(sbi->s_qf_names[qtype]);
1473                 sbi->s_qf_names[qtype] = NULL;
1474                 return 0;
1475         }
1476         set_opt(sb, QUOTA);
1477         return 1;
1478 }
1479
1480 static int clear_qf_name(struct super_block *sb, int qtype)
1481 {
1482
1483         struct ext4_sb_info *sbi = EXT4_SB(sb);
1484
1485         if (sb_any_quota_loaded(sb) &&
1486                 sbi->s_qf_names[qtype]) {
1487                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1488                         " when quota turned on");
1489                 return 0;
1490         }
1491         /*
1492          * The space will be released later when all options are confirmed
1493          * to be correct
1494          */
1495         sbi->s_qf_names[qtype] = NULL;
1496         return 1;
1497 }
1498 #endif
1499
1500 static int parse_options(char *options, struct super_block *sb,
1501                          unsigned long *journal_devnum,
1502                          unsigned int *journal_ioprio,
1503                          ext4_fsblk_t *n_blocks_count, int is_remount)
1504 {
1505         struct ext4_sb_info *sbi = EXT4_SB(sb);
1506         char *p;
1507         substring_t args[MAX_OPT_ARGS];
1508         int data_opt = 0;
1509         int option;
1510 #ifdef CONFIG_QUOTA
1511         int qfmt;
1512 #endif
1513
1514         if (!options)
1515                 return 1;
1516
1517         while ((p = strsep(&options, ",")) != NULL) {
1518                 int token;
1519                 if (!*p)
1520                         continue;
1521
1522                 /*
1523                  * Initialize args struct so we know whether arg was
1524                  * found; some options take optional arguments.
1525                  */
1526                 args[0].to = args[0].from = NULL;
1527                 token = match_token(p, tokens, args);
1528                 switch (token) {
1529                 case Opt_bsd_df:
1530                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1531                         clear_opt(sb, MINIX_DF);
1532                         break;
1533                 case Opt_minix_df:
1534                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1535                         set_opt(sb, MINIX_DF);
1536
1537                         break;
1538                 case Opt_grpid:
1539                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1540                         set_opt(sb, GRPID);
1541
1542                         break;
1543                 case Opt_nogrpid:
1544                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1545                         clear_opt(sb, GRPID);
1546
1547                         break;
1548                 case Opt_resuid:
1549                         if (match_int(&args[0], &option))
1550                                 return 0;
1551                         sbi->s_resuid = option;
1552                         break;
1553                 case Opt_resgid:
1554                         if (match_int(&args[0], &option))
1555                                 return 0;
1556                         sbi->s_resgid = option;
1557                         break;
1558                 case Opt_sb:
1559                         /* handled by get_sb_block() instead of here */
1560                         /* *sb_block = match_int(&args[0]); */
1561                         break;
1562                 case Opt_err_panic:
1563                         clear_opt(sb, ERRORS_CONT);
1564                         clear_opt(sb, ERRORS_RO);
1565                         set_opt(sb, ERRORS_PANIC);
1566                         break;
1567                 case Opt_err_ro:
1568                         clear_opt(sb, ERRORS_CONT);
1569                         clear_opt(sb, ERRORS_PANIC);
1570                         set_opt(sb, ERRORS_RO);
1571                         break;
1572                 case Opt_err_cont:
1573                         clear_opt(sb, ERRORS_RO);
1574                         clear_opt(sb, ERRORS_PANIC);
1575                         set_opt(sb, ERRORS_CONT);
1576                         break;
1577                 case Opt_nouid32:
1578                         set_opt(sb, NO_UID32);
1579                         break;
1580                 case Opt_debug:
1581                         set_opt(sb, DEBUG);
1582                         break;
1583                 case Opt_oldalloc:
1584                         ext4_msg(sb, KERN_WARNING,
1585                                  "Ignoring deprecated oldalloc option");
1586                         break;
1587                 case Opt_orlov:
1588                         ext4_msg(sb, KERN_WARNING,
1589                                  "Ignoring deprecated orlov option");
1590                         break;
1591 #ifdef CONFIG_EXT4_FS_XATTR
1592                 case Opt_user_xattr:
1593                         set_opt(sb, XATTR_USER);
1594                         break;
1595                 case Opt_nouser_xattr:
1596                         clear_opt(sb, XATTR_USER);
1597                         break;
1598 #else
1599                 case Opt_user_xattr:
1600                 case Opt_nouser_xattr:
1601                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1602                         break;
1603 #endif
1604 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1605                 case Opt_acl:
1606                         set_opt(sb, POSIX_ACL);
1607                         break;
1608                 case Opt_noacl:
1609                         clear_opt(sb, POSIX_ACL);
1610                         break;
1611 #else
1612                 case Opt_acl:
1613                 case Opt_noacl:
1614                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1615                         break;
1616 #endif
1617                 case Opt_journal_update:
1618                         /* @@@ FIXME */
1619                         /* Eventually we will want to be able to create
1620                            a journal file here.  For now, only allow the
1621                            user to specify an existing inode to be the
1622                            journal file. */
1623                         if (is_remount) {
1624                                 ext4_msg(sb, KERN_ERR,
1625                                          "Cannot specify journal on remount");
1626                                 return 0;
1627                         }
1628                         set_opt(sb, UPDATE_JOURNAL);
1629                         break;
1630                 case Opt_journal_dev:
1631                         if (is_remount) {
1632                                 ext4_msg(sb, KERN_ERR,
1633                                         "Cannot specify journal on remount");
1634                                 return 0;
1635                         }
1636                         if (match_int(&args[0], &option))
1637                                 return 0;
1638                         *journal_devnum = option;
1639                         break;
1640                 case Opt_journal_checksum:
1641                         set_opt(sb, JOURNAL_CHECKSUM);
1642                         break;
1643                 case Opt_journal_async_commit:
1644                         set_opt(sb, JOURNAL_ASYNC_COMMIT);
1645                         set_opt(sb, JOURNAL_CHECKSUM);
1646                         break;
1647                 case Opt_noload:
1648                         set_opt(sb, NOLOAD);
1649                         break;
1650                 case Opt_commit:
1651                         if (match_int(&args[0], &option))
1652                                 return 0;
1653                         if (option < 0)
1654                                 return 0;
1655                         if (option == 0)
1656                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1657                         sbi->s_commit_interval = HZ * option;
1658                         break;
1659                 case Opt_max_batch_time:
1660                         if (match_int(&args[0], &option))
1661                                 return 0;
1662                         if (option < 0)
1663                                 return 0;
1664                         if (option == 0)
1665                                 option = EXT4_DEF_MAX_BATCH_TIME;
1666                         sbi->s_max_batch_time = option;
1667                         break;
1668                 case Opt_min_batch_time:
1669                         if (match_int(&args[0], &option))
1670                                 return 0;
1671                         if (option < 0)
1672                                 return 0;
1673                         sbi->s_min_batch_time = option;
1674                         break;
1675                 case Opt_data_journal:
1676                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1677                         goto datacheck;
1678                 case Opt_data_ordered:
1679                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1680                         goto datacheck;
1681                 case Opt_data_writeback:
1682                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1683                 datacheck:
1684                         if (is_remount) {
1685                                 if (!sbi->s_journal)
1686                                         ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1687                                 else if (test_opt(sb, DATA_FLAGS) != data_opt) {
1688                                         ext4_msg(sb, KERN_ERR,
1689                                                 "Cannot change data mode on remount");
1690                                         return 0;
1691                                 }
1692                         } else {
1693                                 clear_opt(sb, DATA_FLAGS);
1694                                 sbi->s_mount_opt |= data_opt;
1695                         }
1696                         break;
1697                 case Opt_data_err_abort:
1698                         set_opt(sb, DATA_ERR_ABORT);
1699                         break;
1700                 case Opt_data_err_ignore:
1701                         clear_opt(sb, DATA_ERR_ABORT);
1702                         break;
1703 #ifdef CONFIG_QUOTA
1704                 case Opt_usrjquota:
1705                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1706                                 return 0;
1707                         break;
1708                 case Opt_grpjquota:
1709                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1710                                 return 0;
1711                         break;
1712                 case Opt_offusrjquota:
1713                         if (!clear_qf_name(sb, USRQUOTA))
1714                                 return 0;
1715                         break;
1716                 case Opt_offgrpjquota:
1717                         if (!clear_qf_name(sb, GRPQUOTA))
1718                                 return 0;
1719                         break;
1720
1721                 case Opt_jqfmt_vfsold:
1722                         qfmt = QFMT_VFS_OLD;
1723                         goto set_qf_format;
1724                 case Opt_jqfmt_vfsv0:
1725                         qfmt = QFMT_VFS_V0;
1726                         goto set_qf_format;
1727                 case Opt_jqfmt_vfsv1:
1728                         qfmt = QFMT_VFS_V1;
1729 set_qf_format:
1730                         if (sb_any_quota_loaded(sb) &&
1731                             sbi->s_jquota_fmt != qfmt) {
1732                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1733                                         "journaled quota options when "
1734                                         "quota turned on");
1735                                 return 0;
1736                         }
1737                         sbi->s_jquota_fmt = qfmt;
1738                         break;
1739                 case Opt_quota:
1740                 case Opt_usrquota:
1741                         set_opt(sb, QUOTA);
1742                         set_opt(sb, USRQUOTA);
1743                         break;
1744                 case Opt_grpquota:
1745                         set_opt(sb, QUOTA);
1746                         set_opt(sb, GRPQUOTA);
1747                         break;
1748                 case Opt_noquota:
1749                         if (sb_any_quota_loaded(sb)) {
1750                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1751                                         "options when quota turned on");
1752                                 return 0;
1753                         }
1754                         clear_opt(sb, QUOTA);
1755                         clear_opt(sb, USRQUOTA);
1756                         clear_opt(sb, GRPQUOTA);
1757                         break;
1758 #else
1759                 case Opt_quota:
1760                 case Opt_usrquota:
1761                 case Opt_grpquota:
1762                         ext4_msg(sb, KERN_ERR,
1763                                 "quota options not supported");
1764                         break;
1765                 case Opt_usrjquota:
1766                 case Opt_grpjquota:
1767                 case Opt_offusrjquota:
1768                 case Opt_offgrpjquota:
1769                 case Opt_jqfmt_vfsold:
1770                 case Opt_jqfmt_vfsv0:
1771                 case Opt_jqfmt_vfsv1:
1772                         ext4_msg(sb, KERN_ERR,
1773                                 "journaled quota options not supported");
1774                         break;
1775                 case Opt_noquota:
1776                         break;
1777 #endif
1778                 case Opt_abort:
1779                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1780                         break;
1781                 case Opt_nobarrier:
1782                         clear_opt(sb, BARRIER);
1783                         break;
1784                 case Opt_barrier:
1785                         if (args[0].from) {
1786                                 if (match_int(&args[0], &option))
1787                                         return 0;
1788                         } else
1789                                 option = 1;     /* No argument, default to 1 */
1790                         if (option)
1791                                 set_opt(sb, BARRIER);
1792                         else
1793                                 clear_opt(sb, BARRIER);
1794                         break;
1795                 case Opt_ignore:
1796                         break;
1797                 case Opt_resize:
1798                         if (!is_remount) {
1799                                 ext4_msg(sb, KERN_ERR,
1800                                         "resize option only available "
1801                                         "for remount");
1802                                 return 0;
1803                         }
1804                         if (match_int(&args[0], &option) != 0)
1805                                 return 0;
1806                         *n_blocks_count = option;
1807                         break;
1808                 case Opt_nobh:
1809                         ext4_msg(sb, KERN_WARNING,
1810                                  "Ignoring deprecated nobh option");
1811                         break;
1812                 case Opt_bh:
1813                         ext4_msg(sb, KERN_WARNING,
1814                                  "Ignoring deprecated bh option");
1815                         break;
1816                 case Opt_i_version:
1817                         set_opt(sb, I_VERSION);
1818                         sb->s_flags |= MS_I_VERSION;
1819                         break;
1820                 case Opt_nodelalloc:
1821                         clear_opt(sb, DELALLOC);
1822                         clear_opt2(sb, EXPLICIT_DELALLOC);
1823                         break;
1824                 case Opt_mblk_io_submit:
1825                         set_opt(sb, MBLK_IO_SUBMIT);
1826                         break;
1827                 case Opt_nomblk_io_submit:
1828                         clear_opt(sb, MBLK_IO_SUBMIT);
1829                         break;
1830                 case Opt_stripe:
1831                         if (match_int(&args[0], &option))
1832                                 return 0;
1833                         if (option < 0)
1834                                 return 0;
1835                         sbi->s_stripe = option;
1836                         break;
1837                 case Opt_delalloc:
1838                         set_opt(sb, DELALLOC);
1839                         set_opt2(sb, EXPLICIT_DELALLOC);
1840                         break;
1841                 case Opt_block_validity:
1842                         set_opt(sb, BLOCK_VALIDITY);
1843                         break;
1844                 case Opt_noblock_validity:
1845                         clear_opt(sb, BLOCK_VALIDITY);
1846                         break;
1847                 case Opt_inode_readahead_blks:
1848                         if (match_int(&args[0], &option))
1849                                 return 0;
1850                         if (option < 0 || option > (1 << 30))
1851                                 return 0;
1852                         if (option && !is_power_of_2(option)) {
1853                                 ext4_msg(sb, KERN_ERR,
1854                                          "EXT4-fs: inode_readahead_blks"
1855                                          " must be a power of 2");
1856                                 return 0;
1857                         }
1858                         sbi->s_inode_readahead_blks = option;
1859                         break;
1860                 case Opt_journal_ioprio:
1861                         if (match_int(&args[0], &option))
1862                                 return 0;
1863                         if (option < 0 || option > 7)
1864                                 break;
1865                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1866                                                             option);
1867                         break;
1868                 case Opt_noauto_da_alloc:
1869                         set_opt(sb, NO_AUTO_DA_ALLOC);
1870                         break;
1871                 case Opt_auto_da_alloc:
1872                         if (args[0].from) {
1873                                 if (match_int(&args[0], &option))
1874                                         return 0;
1875                         } else
1876                                 option = 1;     /* No argument, default to 1 */
1877                         if (option)
1878                                 clear_opt(sb, NO_AUTO_DA_ALLOC);
1879                         else
1880                                 set_opt(sb,NO_AUTO_DA_ALLOC);
1881                         break;
1882                 case Opt_discard:
1883                         set_opt(sb, DISCARD);
1884                         break;
1885                 case Opt_nodiscard:
1886                         clear_opt(sb, DISCARD);
1887                         break;
1888                 case Opt_dioread_nolock:
1889                         set_opt(sb, DIOREAD_NOLOCK);
1890                         break;
1891                 case Opt_dioread_lock:
1892                         clear_opt(sb, DIOREAD_NOLOCK);
1893                         break;
1894                 case Opt_init_itable:
1895                         set_opt(sb, INIT_INODE_TABLE);
1896                         if (args[0].from) {
1897                                 if (match_int(&args[0], &option))
1898                                         return 0;
1899                         } else
1900                                 option = EXT4_DEF_LI_WAIT_MULT;
1901                         if (option < 0)
1902                                 return 0;
1903                         sbi->s_li_wait_mult = option;
1904                         break;
1905                 case Opt_noinit_itable:
1906                         clear_opt(sb, INIT_INODE_TABLE);
1907                         break;
1908                 default:
1909                         ext4_msg(sb, KERN_ERR,
1910                                "Unrecognized mount option \"%s\" "
1911                                "or missing value", p);
1912                         return 0;
1913                 }
1914         }
1915 #ifdef CONFIG_QUOTA
1916         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1917                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1918                         clear_opt(sb, USRQUOTA);
1919
1920                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1921                         clear_opt(sb, GRPQUOTA);
1922
1923                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1924                         ext4_msg(sb, KERN_ERR, "old and new quota "
1925                                         "format mixing");
1926                         return 0;
1927                 }
1928
1929                 if (!sbi->s_jquota_fmt) {
1930                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1931                                         "not specified");
1932                         return 0;
1933                 }
1934         } else {
1935                 if (sbi->s_jquota_fmt) {
1936                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1937                                         "specified with no journaling "
1938                                         "enabled");
1939                         return 0;
1940                 }
1941         }
1942 #endif
1943         return 1;
1944 }
1945
1946 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1947                             int read_only)
1948 {
1949         struct ext4_sb_info *sbi = EXT4_SB(sb);
1950         int res = 0;
1951
1952         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1953                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1954                          "forcing read-only mode");
1955                 res = MS_RDONLY;
1956         }
1957         if (read_only)
1958                 goto done;
1959         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1960                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1961                          "running e2fsck is recommended");
1962         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1963                 ext4_msg(sb, KERN_WARNING,
1964                          "warning: mounting fs with errors, "
1965                          "running e2fsck is recommended");
1966         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1967                  le16_to_cpu(es->s_mnt_count) >=
1968                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1969                 ext4_msg(sb, KERN_WARNING,
1970                          "warning: maximal mount count reached, "
1971                          "running e2fsck is recommended");
1972         else if (le32_to_cpu(es->s_checkinterval) &&
1973                 (le32_to_cpu(es->s_lastcheck) +
1974                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1975                 ext4_msg(sb, KERN_WARNING,
1976                          "warning: checktime reached, "
1977                          "running e2fsck is recommended");
1978         if (!sbi->s_journal)
1979                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1980         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1981                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1982         le16_add_cpu(&es->s_mnt_count, 1);
1983         es->s_mtime = cpu_to_le32(get_seconds());
1984         ext4_update_dynamic_rev(sb);
1985         if (sbi->s_journal)
1986                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1987
1988         ext4_commit_super(sb, 1);
1989 done:
1990         if (test_opt(sb, DEBUG))
1991                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1992                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1993                         sb->s_blocksize,
1994                         sbi->s_groups_count,
1995                         EXT4_BLOCKS_PER_GROUP(sb),
1996                         EXT4_INODES_PER_GROUP(sb),
1997                         sbi->s_mount_opt, sbi->s_mount_opt2);
1998
1999         cleancache_init_fs(sb);
2000         return res;
2001 }
2002
2003 static int ext4_fill_flex_info(struct super_block *sb)
2004 {
2005         struct ext4_sb_info *sbi = EXT4_SB(sb);
2006         struct ext4_group_desc *gdp = NULL;
2007         ext4_group_t flex_group_count;
2008         ext4_group_t flex_group;
2009         int groups_per_flex = 0;
2010         size_t size;
2011         int i;
2012
2013         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2014         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
2015
2016         if (groups_per_flex < 2) {
2017                 sbi->s_log_groups_per_flex = 0;
2018                 return 1;
2019         }
2020
2021         /* We allocate both existing and potentially added groups */
2022         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
2023                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
2024                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
2025         size = flex_group_count * sizeof(struct flex_groups);
2026         sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
2027         if (sbi->s_flex_groups == NULL) {
2028                 ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
2029                          flex_group_count);
2030                 goto failed;
2031         }
2032
2033         for (i = 0; i < sbi->s_groups_count; i++) {
2034                 gdp = ext4_get_group_desc(sb, i, NULL);
2035
2036                 flex_group = ext4_flex_group(sbi, i);
2037                 atomic_add(ext4_free_inodes_count(sb, gdp),
2038                            &sbi->s_flex_groups[flex_group].free_inodes);
2039                 atomic_add(ext4_free_group_clusters(sb, gdp),
2040                            &sbi->s_flex_groups[flex_group].free_clusters);
2041                 atomic_add(ext4_used_dirs_count(sb, gdp),
2042                            &sbi->s_flex_groups[flex_group].used_dirs);
2043         }
2044
2045         return 1;
2046 failed:
2047         return 0;
2048 }
2049
2050 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2051                             struct ext4_group_desc *gdp)
2052 {
2053         __u16 crc = 0;
2054
2055         if (sbi->s_es->s_feature_ro_compat &
2056             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
2057                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
2058                 __le32 le_group = cpu_to_le32(block_group);
2059
2060                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2061                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2062                 crc = crc16(crc, (__u8 *)gdp, offset);
2063                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
2064                 /* for checksum of struct ext4_group_desc do the rest...*/
2065                 if ((sbi->s_es->s_feature_incompat &
2066                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2067                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
2068                         crc = crc16(crc, (__u8 *)gdp + offset,
2069                                     le16_to_cpu(sbi->s_es->s_desc_size) -
2070                                         offset);
2071         }
2072
2073         return cpu_to_le16(crc);
2074 }
2075
2076 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2077                                 struct ext4_group_desc *gdp)
2078 {
2079         if ((sbi->s_es->s_feature_ro_compat &
2080              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2081             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2082                 return 0;
2083
2084         return 1;
2085 }
2086
2087 /* Called at mount-time, super-block is locked */
2088 static int ext4_check_descriptors(struct super_block *sb,
2089                                   ext4_group_t *first_not_zeroed)
2090 {
2091         struct ext4_sb_info *sbi = EXT4_SB(sb);
2092         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2093         ext4_fsblk_t last_block;
2094         ext4_fsblk_t block_bitmap;
2095         ext4_fsblk_t inode_bitmap;
2096         ext4_fsblk_t inode_table;
2097         int flexbg_flag = 0;
2098         ext4_group_t i, grp = sbi->s_groups_count;
2099
2100         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2101                 flexbg_flag = 1;
2102
2103         ext4_debug("Checking group descriptors");
2104
2105         for (i = 0; i < sbi->s_groups_count; i++) {
2106                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2107
2108                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2109                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2110                 else
2111                         last_block = first_block +
2112                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2113
2114                 if ((grp == sbi->s_groups_count) &&
2115                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2116                         grp = i;
2117
2118                 block_bitmap = ext4_block_bitmap(sb, gdp);
2119                 if (block_bitmap < first_block || block_bitmap > last_block) {
2120                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2121                                "Block bitmap for group %u not in group "
2122                                "(block %llu)!", i, block_bitmap);
2123                         return 0;
2124                 }
2125                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2126                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2127                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2128                                "Inode bitmap for group %u not in group "
2129                                "(block %llu)!", i, inode_bitmap);
2130                         return 0;
2131                 }
2132                 inode_table = ext4_inode_table(sb, gdp);
2133                 if (inode_table < first_block ||
2134                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2135                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2136                                "Inode table for group %u not in group "
2137                                "(block %llu)!", i, inode_table);
2138                         return 0;
2139                 }
2140                 ext4_lock_group(sb, i);
2141                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2142                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2143                                  "Checksum for group %u failed (%u!=%u)",
2144                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2145                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2146                         if (!(sb->s_flags & MS_RDONLY)) {
2147                                 ext4_unlock_group(sb, i);
2148                                 return 0;
2149                         }
2150                 }
2151                 ext4_unlock_group(sb, i);
2152                 if (!flexbg_flag)
2153                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2154         }
2155         if (NULL != first_not_zeroed)
2156                 *first_not_zeroed = grp;
2157
2158         ext4_free_blocks_count_set(sbi->s_es,
2159                                    EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2160         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2161         return 1;
2162 }
2163
2164 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2165  * the superblock) which were deleted from all directories, but held open by
2166  * a process at the time of a crash.  We walk the list and try to delete these
2167  * inodes at recovery time (only with a read-write filesystem).
2168  *
2169  * In order to keep the orphan inode chain consistent during traversal (in
2170  * case of crash during recovery), we link each inode into the superblock
2171  * orphan list_head and handle it the same way as an inode deletion during
2172  * normal operation (which journals the operations for us).
2173  *
2174  * We only do an iget() and an iput() on each inode, which is very safe if we
2175  * accidentally point at an in-use or already deleted inode.  The worst that
2176  * can happen in this case is that we get a "bit already cleared" message from
2177  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2178  * e2fsck was run on this filesystem, and it must have already done the orphan
2179  * inode cleanup for us, so we can safely abort without any further action.
2180  */
2181 static void ext4_orphan_cleanup(struct super_block *sb,
2182                                 struct ext4_super_block *es)
2183 {
2184         unsigned int s_flags = sb->s_flags;
2185         int nr_orphans = 0, nr_truncates = 0;
2186 #ifdef CONFIG_QUOTA
2187         int i;
2188 #endif
2189         if (!es->s_last_orphan) {
2190                 jbd_debug(4, "no orphan inodes to clean up\n");
2191                 return;
2192         }
2193
2194         if (bdev_read_only(sb->s_bdev)) {
2195                 ext4_msg(sb, KERN_ERR, "write access "
2196                         "unavailable, skipping orphan cleanup");
2197                 return;
2198         }
2199
2200         /* Check if feature set would not allow a r/w mount */
2201         if (!ext4_feature_set_ok(sb, 0)) {
2202                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2203                          "unknown ROCOMPAT features");
2204                 return;
2205         }
2206
2207         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2208                 if (es->s_last_orphan)
2209                         jbd_debug(1, "Errors on filesystem, "
2210                                   "clearing orphan list.\n");
2211                 es->s_last_orphan = 0;
2212                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2213                 return;
2214         }
2215
2216         if (s_flags & MS_RDONLY) {
2217                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2218                 sb->s_flags &= ~MS_RDONLY;
2219         }
2220 #ifdef CONFIG_QUOTA
2221         /* Needed for iput() to work correctly and not trash data */
2222         sb->s_flags |= MS_ACTIVE;
2223         /* Turn on quotas so that they are updated correctly */
2224         for (i = 0; i < MAXQUOTAS; i++) {
2225                 if (EXT4_SB(sb)->s_qf_names[i]) {
2226                         int ret = ext4_quota_on_mount(sb, i);
2227                         if (ret < 0)
2228                                 ext4_msg(sb, KERN_ERR,
2229                                         "Cannot turn on journaled "
2230                                         "quota: error %d", ret);
2231                 }
2232         }
2233 #endif
2234
2235         while (es->s_last_orphan) {
2236                 struct inode *inode;
2237
2238                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2239                 if (IS_ERR(inode)) {
2240                         es->s_last_orphan = 0;
2241                         break;
2242                 }
2243
2244                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2245                 dquot_initialize(inode);
2246                 if (inode->i_nlink) {
2247                         ext4_msg(sb, KERN_DEBUG,
2248                                 "%s: truncating inode %lu to %lld bytes",
2249                                 __func__, inode->i_ino, inode->i_size);
2250                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2251                                   inode->i_ino, inode->i_size);
2252                         ext4_truncate(inode);
2253                         nr_truncates++;
2254                 } else {
2255                         ext4_msg(sb, KERN_DEBUG,
2256                                 "%s: deleting unreferenced inode %lu",
2257                                 __func__, inode->i_ino);
2258                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2259                                   inode->i_ino);
2260                         nr_orphans++;
2261                 }
2262                 iput(inode);  /* The delete magic happens here! */
2263         }
2264
2265 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2266
2267         if (nr_orphans)
2268                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2269                        PLURAL(nr_orphans));
2270         if (nr_truncates)
2271                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2272                        PLURAL(nr_truncates));
2273 #ifdef CONFIG_QUOTA
2274         /* Turn quotas off */
2275         for (i = 0; i < MAXQUOTAS; i++) {
2276                 if (sb_dqopt(sb)->files[i])
2277                         dquot_quota_off(sb, i);
2278         }
2279 #endif
2280         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2281 }
2282
2283 /*
2284  * Maximal extent format file size.
2285  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2286  * extent format containers, within a sector_t, and within i_blocks
2287  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2288  * so that won't be a limiting factor.
2289  *
2290  * However there is other limiting factor. We do store extents in the form
2291  * of starting block and length, hence the resulting length of the extent
2292  * covering maximum file size must fit into on-disk format containers as
2293  * well. Given that length is always by 1 unit bigger than max unit (because
2294  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2295  *
2296  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2297  */
2298 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2299 {
2300         loff_t res;
2301         loff_t upper_limit = MAX_LFS_FILESIZE;
2302
2303         /* small i_blocks in vfs inode? */
2304         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2305                 /*
2306                  * CONFIG_LBDAF is not enabled implies the inode
2307                  * i_block represent total blocks in 512 bytes
2308                  * 32 == size of vfs inode i_blocks * 8
2309                  */
2310                 upper_limit = (1LL << 32) - 1;
2311
2312                 /* total blocks in file system block size */
2313                 upper_limit >>= (blkbits - 9);
2314                 upper_limit <<= blkbits;
2315         }
2316
2317         /*
2318          * 32-bit extent-start container, ee_block. We lower the maxbytes
2319          * by one fs block, so ee_len can cover the extent of maximum file
2320          * size
2321          */
2322         res = (1LL << 32) - 1;
2323         res <<= blkbits;
2324
2325         /* Sanity check against vm- & vfs- imposed limits */
2326         if (res > upper_limit)
2327                 res = upper_limit;
2328
2329         return res;
2330 }
2331
2332 /*
2333  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2334  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2335  * We need to be 1 filesystem block less than the 2^48 sector limit.
2336  */
2337 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2338 {
2339         loff_t res = EXT4_NDIR_BLOCKS;
2340         int meta_blocks;
2341         loff_t upper_limit;
2342         /* This is calculated to be the largest file size for a dense, block
2343          * mapped file such that the file's total number of 512-byte sectors,
2344          * including data and all indirect blocks, does not exceed (2^48 - 1).
2345          *
2346          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2347          * number of 512-byte sectors of the file.
2348          */
2349
2350         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2351                 /*
2352                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2353                  * the inode i_block field represents total file blocks in
2354                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2355                  */
2356                 upper_limit = (1LL << 32) - 1;
2357
2358                 /* total blocks in file system block size */
2359                 upper_limit >>= (bits - 9);
2360
2361         } else {
2362                 /*
2363                  * We use 48 bit ext4_inode i_blocks
2364                  * With EXT4_HUGE_FILE_FL set the i_blocks
2365                  * represent total number of blocks in
2366                  * file system block size
2367                  */
2368                 upper_limit = (1LL << 48) - 1;
2369
2370         }
2371
2372         /* indirect blocks */
2373         meta_blocks = 1;
2374         /* double indirect blocks */
2375         meta_blocks += 1 + (1LL << (bits-2));
2376         /* tripple indirect blocks */
2377         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2378
2379         upper_limit -= meta_blocks;
2380         upper_limit <<= bits;
2381
2382         res += 1LL << (bits-2);
2383         res += 1LL << (2*(bits-2));
2384         res += 1LL << (3*(bits-2));
2385         res <<= bits;
2386         if (res > upper_limit)
2387                 res = upper_limit;
2388
2389         if (res > MAX_LFS_FILESIZE)
2390                 res = MAX_LFS_FILESIZE;
2391
2392         return res;
2393 }
2394
2395 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2396                                    ext4_fsblk_t logical_sb_block, int nr)
2397 {
2398         struct ext4_sb_info *sbi = EXT4_SB(sb);
2399         ext4_group_t bg, first_meta_bg;
2400         int has_super = 0;
2401
2402         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2403
2404         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2405             nr < first_meta_bg)
2406                 return logical_sb_block + nr + 1;
2407         bg = sbi->s_desc_per_block * nr;
2408         if (ext4_bg_has_super(sb, bg))
2409                 has_super = 1;
2410
2411         return (has_super + ext4_group_first_block_no(sb, bg));
2412 }
2413
2414 /**
2415  * ext4_get_stripe_size: Get the stripe size.
2416  * @sbi: In memory super block info
2417  *
2418  * If we have specified it via mount option, then
2419  * use the mount option value. If the value specified at mount time is
2420  * greater than the blocks per group use the super block value.
2421  * If the super block value is greater than blocks per group return 0.
2422  * Allocator needs it be less than blocks per group.
2423  *
2424  */
2425 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2426 {
2427         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2428         unsigned long stripe_width =
2429                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2430         int ret;
2431
2432         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2433                 ret = sbi->s_stripe;
2434         else if (stripe_width <= sbi->s_blocks_per_group)
2435                 ret = stripe_width;
2436         else if (stride <= sbi->s_blocks_per_group)
2437                 ret = stride;
2438         else
2439                 ret = 0;
2440
2441         /*
2442          * If the stripe width is 1, this makes no sense and
2443          * we set it to 0 to turn off stripe handling code.
2444          */
2445         if (ret <= 1)
2446                 ret = 0;
2447
2448         return ret;
2449 }
2450
2451 /* sysfs supprt */
2452
2453 struct ext4_attr {
2454         struct attribute attr;
2455         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2456         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2457                          const char *, size_t);
2458         int offset;
2459 };
2460
2461 static int parse_strtoul(const char *buf,
2462                 unsigned long max, unsigned long *value)
2463 {
2464         char *endp;
2465
2466         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2467         endp = skip_spaces(endp);
2468         if (*endp || *value > max)
2469                 return -EINVAL;
2470
2471         return 0;
2472 }
2473
2474 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2475                                               struct ext4_sb_info *sbi,
2476                                               char *buf)
2477 {
2478         return snprintf(buf, PAGE_SIZE, "%llu\n",
2479                 (s64) EXT4_C2B(sbi,
2480                         percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2481 }
2482
2483 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2484                                          struct ext4_sb_info *sbi, char *buf)
2485 {
2486         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2487
2488         if (!sb->s_bdev->bd_part)
2489                 return snprintf(buf, PAGE_SIZE, "0\n");
2490         return snprintf(buf, PAGE_SIZE, "%lu\n",
2491                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2492                          sbi->s_sectors_written_start) >> 1);
2493 }
2494
2495 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2496                                           struct ext4_sb_info *sbi, char *buf)
2497 {
2498         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2499
2500         if (!sb->s_bdev->bd_part)
2501                 return snprintf(buf, PAGE_SIZE, "0\n");
2502         return snprintf(buf, PAGE_SIZE, "%llu\n",
2503                         (unsigned long long)(sbi->s_kbytes_written +
2504                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2505                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2506 }
2507
2508 static ssize_t extent_cache_hits_show(struct ext4_attr *a,
2509                                       struct ext4_sb_info *sbi, char *buf)
2510 {
2511         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
2512 }
2513
2514 static ssize_t extent_cache_misses_show(struct ext4_attr *a,
2515                                         struct ext4_sb_info *sbi, char *buf)
2516 {
2517         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
2518 }
2519
2520 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2521                                           struct ext4_sb_info *sbi,
2522                                           const char *buf, size_t count)
2523 {
2524         unsigned long t;
2525
2526         if (parse_strtoul(buf, 0x40000000, &t))
2527                 return -EINVAL;
2528
2529         if (t && !is_power_of_2(t))
2530                 return -EINVAL;
2531
2532         sbi->s_inode_readahead_blks = t;
2533         return count;
2534 }
2535
2536 static ssize_t sbi_ui_show(struct ext4_attr *a,
2537                            struct ext4_sb_info *sbi, char *buf)
2538 {
2539         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2540
2541         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2542 }
2543
2544 static ssize_t sbi_ui_store(struct ext4_attr *a,
2545                             struct ext4_sb_info *sbi,
2546                             const char *buf, size_t count)
2547 {
2548         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2549         unsigned long t;
2550
2551         if (parse_strtoul(buf, 0xffffffff, &t))
2552                 return -EINVAL;
2553         *ui = t;
2554         return count;
2555 }
2556
2557 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2558 static struct ext4_attr ext4_attr_##_name = {                   \
2559         .attr = {.name = __stringify(_name), .mode = _mode },   \
2560         .show   = _show,                                        \
2561         .store  = _store,                                       \
2562         .offset = offsetof(struct ext4_sb_info, _elname),       \
2563 }
2564 #define EXT4_ATTR(name, mode, show, store) \
2565 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2566
2567 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2568 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2569 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2570 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2571         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2572 #define ATTR_LIST(name) &ext4_attr_##name.attr
2573
2574 EXT4_RO_ATTR(delayed_allocation_blocks);
2575 EXT4_RO_ATTR(session_write_kbytes);
2576 EXT4_RO_ATTR(lifetime_write_kbytes);
2577 EXT4_RO_ATTR(extent_cache_hits);
2578 EXT4_RO_ATTR(extent_cache_misses);
2579 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2580                  inode_readahead_blks_store, s_inode_readahead_blks);
2581 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2582 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2583 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2584 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2585 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2586 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2587 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2588 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2589
2590 static struct attribute *ext4_attrs[] = {
2591         ATTR_LIST(delayed_allocation_blocks),
2592         ATTR_LIST(session_write_kbytes),
2593         ATTR_LIST(lifetime_write_kbytes),
2594         ATTR_LIST(extent_cache_hits),
2595         ATTR_LIST(extent_cache_misses),
2596         ATTR_LIST(inode_readahead_blks),
2597         ATTR_LIST(inode_goal),
2598         ATTR_LIST(mb_stats),
2599         ATTR_LIST(mb_max_to_scan),
2600         ATTR_LIST(mb_min_to_scan),
2601         ATTR_LIST(mb_order2_req),
2602         ATTR_LIST(mb_stream_req),
2603         ATTR_LIST(mb_group_prealloc),
2604         ATTR_LIST(max_writeback_mb_bump),
2605         NULL,
2606 };
2607
2608 /* Features this copy of ext4 supports */
2609 EXT4_INFO_ATTR(lazy_itable_init);
2610 EXT4_INFO_ATTR(batched_discard);
2611
2612 static struct attribute *ext4_feat_attrs[] = {
2613         ATTR_LIST(lazy_itable_init),
2614         ATTR_LIST(batched_discard),
2615         NULL,
2616 };
2617
2618 static ssize_t ext4_attr_show(struct kobject *kobj,
2619                               struct attribute *attr, char *buf)
2620 {
2621         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2622                                                 s_kobj);
2623         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2624
2625         return a->show ? a->show(a, sbi, buf) : 0;
2626 }
2627
2628 static ssize_t ext4_attr_store(struct kobject *kobj,
2629                                struct attribute *attr,
2630                                const char *buf, size_t len)
2631 {
2632         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2633                                                 s_kobj);
2634         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2635
2636         return a->store ? a->store(a, sbi, buf, len) : 0;
2637 }
2638
2639 static void ext4_sb_release(struct kobject *kobj)
2640 {
2641         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2642                                                 s_kobj);
2643         complete(&sbi->s_kobj_unregister);
2644 }
2645
2646 static const struct sysfs_ops ext4_attr_ops = {
2647         .show   = ext4_attr_show,
2648         .store  = ext4_attr_store,
2649 };
2650
2651 static struct kobj_type ext4_ktype = {
2652         .default_attrs  = ext4_attrs,
2653         .sysfs_ops      = &ext4_attr_ops,
2654         .release        = ext4_sb_release,
2655 };
2656
2657 static void ext4_feat_release(struct kobject *kobj)
2658 {
2659         complete(&ext4_feat->f_kobj_unregister);
2660 }
2661
2662 static struct kobj_type ext4_feat_ktype = {
2663         .default_attrs  = ext4_feat_attrs,
2664         .sysfs_ops      = &ext4_attr_ops,
2665         .release        = ext4_feat_release,
2666 };
2667
2668 /*
2669  * Check whether this filesystem can be mounted based on
2670  * the features present and the RDONLY/RDWR mount requested.
2671  * Returns 1 if this filesystem can be mounted as requested,
2672  * 0 if it cannot be.
2673  */
2674 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2675 {
2676         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2677                 ext4_msg(sb, KERN_ERR,
2678                         "Couldn't mount because of "
2679                         "unsupported optional features (%x)",
2680                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2681                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2682                 return 0;
2683         }
2684
2685         if (readonly)
2686                 return 1;
2687
2688         /* Check that feature set is OK for a read-write mount */
2689         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2690                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2691                          "unsupported optional features (%x)",
2692                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2693                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2694                 return 0;
2695         }
2696         /*
2697          * Large file size enabled file system can only be mounted
2698          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2699          */
2700         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2701                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2702                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2703                                  "cannot be mounted RDWR without "
2704                                  "CONFIG_LBDAF");
2705                         return 0;
2706                 }
2707         }
2708         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2709             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2710                 ext4_msg(sb, KERN_ERR,
2711                          "Can't support bigalloc feature without "
2712                          "extents feature\n");
2713                 return 0;
2714         }
2715         return 1;
2716 }
2717
2718 /*
2719  * This function is called once a day if we have errors logged
2720  * on the file system
2721  */
2722 static void print_daily_error_info(unsigned long arg)
2723 {
2724         struct super_block *sb = (struct super_block *) arg;
2725         struct ext4_sb_info *sbi;
2726         struct ext4_super_block *es;
2727
2728         sbi = EXT4_SB(sb);
2729         es = sbi->s_es;
2730
2731         if (es->s_error_count)
2732                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2733                          le32_to_cpu(es->s_error_count));
2734         if (es->s_first_error_time) {
2735                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2736                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2737                        (int) sizeof(es->s_first_error_func),
2738                        es->s_first_error_func,
2739                        le32_to_cpu(es->s_first_error_line));
2740                 if (es->s_first_error_ino)
2741                         printk(": inode %u",
2742                                le32_to_cpu(es->s_first_error_ino));
2743                 if (es->s_first_error_block)
2744                         printk(": block %llu", (unsigned long long)
2745                                le64_to_cpu(es->s_first_error_block));
2746                 printk("\n");
2747         }
2748         if (es->s_last_error_time) {
2749                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2750                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2751                        (int) sizeof(es->s_last_error_func),
2752                        es->s_last_error_func,
2753                        le32_to_cpu(es->s_last_error_line));
2754                 if (es->s_last_error_ino)
2755                         printk(": inode %u",
2756                                le32_to_cpu(es->s_last_error_ino));
2757                 if (es->s_last_error_block)
2758                         printk(": block %llu", (unsigned long long)
2759                                le64_to_cpu(es->s_last_error_block));
2760                 printk("\n");
2761         }
2762         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2763 }
2764
2765 /* Find next suitable group and run ext4_init_inode_table */
2766 static int ext4_run_li_request(struct ext4_li_request *elr)
2767 {
2768         struct ext4_group_desc *gdp = NULL;
2769         ext4_group_t group, ngroups;
2770         struct super_block *sb;
2771         unsigned long timeout = 0;
2772         int ret = 0;
2773
2774         sb = elr->lr_super;
2775         ngroups = EXT4_SB(sb)->s_groups_count;
2776
2777         for (group = elr->lr_next_group; group < ngroups; group++) {
2778                 gdp = ext4_get_group_desc(sb, group, NULL);
2779                 if (!gdp) {
2780                         ret = 1;
2781                         break;
2782                 }
2783
2784                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2785                         break;
2786         }
2787
2788         if (group == ngroups)
2789                 ret = 1;
2790
2791         if (!ret) {
2792                 timeout = jiffies;
2793                 ret = ext4_init_inode_table(sb, group,
2794                                             elr->lr_timeout ? 0 : 1);
2795                 if (elr->lr_timeout == 0) {
2796                         timeout = (jiffies - timeout) *
2797                                   elr->lr_sbi->s_li_wait_mult;
2798                         elr->lr_timeout = timeout;
2799                 }
2800                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2801                 elr->lr_next_group = group + 1;
2802         }
2803
2804         return ret;
2805 }
2806
2807 /*
2808  * Remove lr_request from the list_request and free the
2809  * request structure. Should be called with li_list_mtx held
2810  */
2811 static void ext4_remove_li_request(struct ext4_li_request *elr)
2812 {
2813         struct ext4_sb_info *sbi;
2814
2815         if (!elr)
2816                 return;
2817
2818         sbi = elr->lr_sbi;
2819
2820         list_del(&elr->lr_request);
2821         sbi->s_li_request = NULL;
2822         kfree(elr);
2823 }
2824
2825 static void ext4_unregister_li_request(struct super_block *sb)
2826 {
2827         mutex_lock(&ext4_li_mtx);
2828         if (!ext4_li_info) {
2829                 mutex_unlock(&ext4_li_mtx);
2830                 return;
2831         }
2832
2833         mutex_lock(&ext4_li_info->li_list_mtx);
2834         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2835         mutex_unlock(&ext4_li_info->li_list_mtx);
2836         mutex_unlock(&ext4_li_mtx);
2837 }
2838
2839 static struct task_struct *ext4_lazyinit_task;
2840
2841 /*
2842  * This is the function where ext4lazyinit thread lives. It walks
2843  * through the request list searching for next scheduled filesystem.
2844  * When such a fs is found, run the lazy initialization request
2845  * (ext4_rn_li_request) and keep track of the time spend in this
2846  * function. Based on that time we compute next schedule time of
2847  * the request. When walking through the list is complete, compute
2848  * next waking time and put itself into sleep.
2849  */
2850 static int ext4_lazyinit_thread(void *arg)
2851 {
2852         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2853         struct list_head *pos, *n;
2854         struct ext4_li_request *elr;
2855         unsigned long next_wakeup, cur;
2856
2857         BUG_ON(NULL == eli);
2858
2859 cont_thread:
2860         while (true) {
2861                 next_wakeup = MAX_JIFFY_OFFSET;
2862
2863                 mutex_lock(&eli->li_list_mtx);
2864                 if (list_empty(&eli->li_request_list)) {
2865                         mutex_unlock(&eli->li_list_mtx);
2866                         goto exit_thread;
2867                 }
2868
2869                 list_for_each_safe(pos, n, &eli->li_request_list) {
2870                         elr = list_entry(pos, struct ext4_li_request,
2871                                          lr_request);
2872
2873                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2874                                 if (ext4_run_li_request(elr) != 0) {
2875                                         /* error, remove the lazy_init job */
2876                                         ext4_remove_li_request(elr);
2877                                         continue;
2878                                 }
2879                         }
2880
2881                         if (time_before(elr->lr_next_sched, next_wakeup))
2882                                 next_wakeup = elr->lr_next_sched;
2883                 }
2884                 mutex_unlock(&eli->li_list_mtx);
2885
2886                 if (freezing(current))
2887                         refrigerator();
2888
2889                 cur = jiffies;
2890                 if ((time_after_eq(cur, next_wakeup)) ||
2891                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2892                         cond_resched();
2893                         continue;
2894                 }
2895
2896                 schedule_timeout_interruptible(next_wakeup - cur);
2897
2898                 if (kthread_should_stop()) {
2899                         ext4_clear_request_list();
2900                         goto exit_thread;
2901                 }
2902         }
2903
2904 exit_thread:
2905         /*
2906          * It looks like the request list is empty, but we need
2907          * to check it under the li_list_mtx lock, to prevent any
2908          * additions into it, and of course we should lock ext4_li_mtx
2909          * to atomically free the list and ext4_li_info, because at
2910          * this point another ext4 filesystem could be registering
2911          * new one.
2912          */
2913         mutex_lock(&ext4_li_mtx);
2914         mutex_lock(&eli->li_list_mtx);
2915         if (!list_empty(&eli->li_request_list)) {
2916                 mutex_unlock(&eli->li_list_mtx);
2917                 mutex_unlock(&ext4_li_mtx);
2918                 goto cont_thread;
2919         }
2920         mutex_unlock(&eli->li_list_mtx);
2921         kfree(ext4_li_info);
2922         ext4_li_info = NULL;
2923         mutex_unlock(&ext4_li_mtx);
2924
2925         return 0;
2926 }
2927
2928 static void ext4_clear_request_list(void)
2929 {
2930         struct list_head *pos, *n;
2931         struct ext4_li_request *elr;
2932
2933         mutex_lock(&ext4_li_info->li_list_mtx);
2934         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2935                 elr = list_entry(pos, struct ext4_li_request,
2936                                  lr_request);
2937                 ext4_remove_li_request(elr);
2938         }
2939         mutex_unlock(&ext4_li_info->li_list_mtx);
2940 }
2941
2942 static int ext4_run_lazyinit_thread(void)
2943 {
2944         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2945                                          ext4_li_info, "ext4lazyinit");
2946         if (IS_ERR(ext4_lazyinit_task)) {
2947                 int err = PTR_ERR(ext4_lazyinit_task);
2948                 ext4_clear_request_list();
2949                 kfree(ext4_li_info);
2950                 ext4_li_info = NULL;
2951                 printk(KERN_CRIT "EXT4: error %d creating inode table "
2952                                  "initialization thread\n",
2953                                  err);
2954                 return err;
2955         }
2956         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2957         return 0;
2958 }
2959
2960 /*
2961  * Check whether it make sense to run itable init. thread or not.
2962  * If there is at least one uninitialized inode table, return
2963  * corresponding group number, else the loop goes through all
2964  * groups and return total number of groups.
2965  */
2966 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2967 {
2968         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2969         struct ext4_group_desc *gdp = NULL;
2970
2971         for (group = 0; group < ngroups; group++) {
2972                 gdp = ext4_get_group_desc(sb, group, NULL);
2973                 if (!gdp)
2974                         continue;
2975
2976                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2977                         break;
2978         }
2979
2980         return group;
2981 }
2982
2983 static int ext4_li_info_new(void)
2984 {
2985         struct ext4_lazy_init *eli = NULL;
2986
2987         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2988         if (!eli)
2989                 return -ENOMEM;
2990
2991         INIT_LIST_HEAD(&eli->li_request_list);
2992         mutex_init(&eli->li_list_mtx);
2993
2994         eli->li_state |= EXT4_LAZYINIT_QUIT;
2995
2996         ext4_li_info = eli;
2997
2998         return 0;
2999 }
3000
3001 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3002                                             ext4_group_t start)
3003 {
3004         struct ext4_sb_info *sbi = EXT4_SB(sb);
3005         struct ext4_li_request *elr;
3006         unsigned long rnd;
3007
3008         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3009         if (!elr)
3010                 return NULL;
3011
3012         elr->lr_super = sb;
3013         elr->lr_sbi = sbi;
3014         elr->lr_next_group = start;
3015
3016         /*
3017          * Randomize first schedule time of the request to
3018          * spread the inode table initialization requests
3019          * better.
3020          */
3021         get_random_bytes(&rnd, sizeof(rnd));
3022         elr->lr_next_sched = jiffies + (unsigned long)rnd %
3023                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3024
3025         return elr;
3026 }
3027
3028 static int ext4_register_li_request(struct super_block *sb,
3029                                     ext4_group_t first_not_zeroed)
3030 {
3031         struct ext4_sb_info *sbi = EXT4_SB(sb);
3032         struct ext4_li_request *elr;
3033         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3034         int ret = 0;
3035
3036         if (sbi->s_li_request != NULL) {
3037                 /*
3038                  * Reset timeout so it can be computed again, because
3039                  * s_li_wait_mult might have changed.
3040                  */
3041                 sbi->s_li_request->lr_timeout = 0;
3042                 return 0;
3043         }
3044
3045         if (first_not_zeroed == ngroups ||
3046             (sb->s_flags & MS_RDONLY) ||
3047             !test_opt(sb, INIT_INODE_TABLE))
3048                 return 0;
3049
3050         elr = ext4_li_request_new(sb, first_not_zeroed);
3051         if (!elr)
3052                 return -ENOMEM;
3053
3054         mutex_lock(&ext4_li_mtx);
3055
3056         if (NULL == ext4_li_info) {
3057                 ret = ext4_li_info_new();
3058                 if (ret)
3059                         goto out;
3060         }
3061
3062         mutex_lock(&ext4_li_info->li_list_mtx);
3063         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3064         mutex_unlock(&ext4_li_info->li_list_mtx);
3065
3066         sbi->s_li_request = elr;
3067         /*
3068          * set elr to NULL here since it has been inserted to
3069          * the request_list and the removal and free of it is
3070          * handled by ext4_clear_request_list from now on.
3071          */
3072         elr = NULL;
3073
3074         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3075                 ret = ext4_run_lazyinit_thread();
3076                 if (ret)
3077                         goto out;
3078         }
3079 out:
3080         mutex_unlock(&ext4_li_mtx);
3081         if (ret)
3082                 kfree(elr);
3083         return ret;
3084 }
3085
3086 /*
3087  * We do not need to lock anything since this is called on
3088  * module unload.
3089  */
3090 static void ext4_destroy_lazyinit_thread(void)
3091 {
3092         /*
3093          * If thread exited earlier
3094          * there's nothing to be done.
3095          */
3096         if (!ext4_li_info || !ext4_lazyinit_task)
3097                 return;
3098
3099         kthread_stop(ext4_lazyinit_task);
3100 }
3101
3102 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3103 {
3104         char *orig_data = kstrdup(data, GFP_KERNEL);
3105         struct buffer_head *bh;
3106         struct ext4_super_block *es = NULL;
3107         struct ext4_sb_info *sbi;
3108         ext4_fsblk_t block;
3109         ext4_fsblk_t sb_block = get_sb_block(&data);
3110         ext4_fsblk_t logical_sb_block;
3111         unsigned long offset = 0;
3112         unsigned long journal_devnum = 0;
3113         unsigned long def_mount_opts;
3114         struct inode *root;
3115         char *cp;
3116         const char *descr;
3117         int ret = -ENOMEM;
3118         int blocksize, clustersize;
3119         unsigned int db_count;
3120         unsigned int i;
3121         int needs_recovery, has_huge_files, has_bigalloc;
3122         __u64 blocks_count;
3123         int err;
3124         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3125         ext4_group_t first_not_zeroed;
3126
3127         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3128         if (!sbi)
3129                 goto out_free_orig;
3130
3131         sbi->s_blockgroup_lock =
3132                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3133         if (!sbi->s_blockgroup_lock) {
3134                 kfree(sbi);
3135                 goto out_free_orig;
3136         }
3137         sb->s_fs_info = sbi;
3138         sbi->s_mount_opt = 0;
3139         sbi->s_resuid = EXT4_DEF_RESUID;
3140         sbi->s_resgid = EXT4_DEF_RESGID;
3141         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3142         sbi->s_sb_block = sb_block;
3143         if (sb->s_bdev->bd_part)
3144                 sbi->s_sectors_written_start =
3145                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3146
3147         /* Cleanup superblock name */
3148         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3149                 *cp = '!';
3150
3151         ret = -EINVAL;
3152         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3153         if (!blocksize) {
3154                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3155                 goto out_fail;
3156         }
3157
3158         /*
3159          * The ext4 superblock will not be buffer aligned for other than 1kB
3160          * block sizes.  We need to calculate the offset from buffer start.
3161          */
3162         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3163                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3164                 offset = do_div(logical_sb_block, blocksize);
3165         } else {
3166                 logical_sb_block = sb_block;
3167         }
3168
3169         if (!(bh = sb_bread(sb, logical_sb_block))) {
3170                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3171                 goto out_fail;
3172         }
3173         /*
3174          * Note: s_es must be initialized as soon as possible because
3175          *       some ext4 macro-instructions depend on its value
3176          */
3177         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3178         sbi->s_es = es;
3179         sb->s_magic = le16_to_cpu(es->s_magic);
3180         if (sb->s_magic != EXT4_SUPER_MAGIC)
3181                 goto cantfind_ext4;
3182         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3183
3184         /* Set defaults before we parse the mount options */
3185         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3186         set_opt(sb, INIT_INODE_TABLE);
3187         if (def_mount_opts & EXT4_DEFM_DEBUG)
3188                 set_opt(sb, DEBUG);
3189         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3190                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3191                         "2.6.38");
3192                 set_opt(sb, GRPID);
3193         }
3194         if (def_mount_opts & EXT4_DEFM_UID16)
3195                 set_opt(sb, NO_UID32);
3196         /* xattr user namespace & acls are now defaulted on */
3197 #ifdef CONFIG_EXT4_FS_XATTR
3198         set_opt(sb, XATTR_USER);
3199 #endif
3200 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3201         set_opt(sb, POSIX_ACL);
3202 #endif
3203         set_opt(sb, MBLK_IO_SUBMIT);
3204         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3205                 set_opt(sb, JOURNAL_DATA);
3206         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3207                 set_opt(sb, ORDERED_DATA);
3208         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3209                 set_opt(sb, WRITEBACK_DATA);
3210
3211         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3212                 set_opt(sb, ERRORS_PANIC);
3213         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3214                 set_opt(sb, ERRORS_CONT);
3215         else
3216                 set_opt(sb, ERRORS_RO);
3217         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3218                 set_opt(sb, BLOCK_VALIDITY);
3219         if (def_mount_opts & EXT4_DEFM_DISCARD)
3220                 set_opt(sb, DISCARD);
3221
3222         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3223         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3224         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3225         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3226         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3227
3228         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3229                 set_opt(sb, BARRIER);
3230
3231         /*
3232          * enable delayed allocation by default
3233          * Use -o nodelalloc to turn it off
3234          */
3235         if (!IS_EXT3_SB(sb) &&
3236             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3237                 set_opt(sb, DELALLOC);
3238
3239         /*
3240          * set default s_li_wait_mult for lazyinit, for the case there is
3241          * no mount option specified.
3242          */
3243         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3244
3245         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3246                            &journal_devnum, &journal_ioprio, NULL, 0)) {
3247                 ext4_msg(sb, KERN_WARNING,
3248                          "failed to parse options in superblock: %s",
3249                          sbi->s_es->s_mount_opts);
3250         }
3251         if (!parse_options((char *) data, sb, &journal_devnum,
3252                            &journal_ioprio, NULL, 0))
3253                 goto failed_mount;
3254
3255         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3256                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3257                             "with data=journal disables delayed "
3258                             "allocation and O_DIRECT support!\n");
3259                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3260                         ext4_msg(sb, KERN_ERR, "can't mount with "
3261                                  "both data=journal and delalloc");
3262                         goto failed_mount;
3263                 }
3264                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3265                         ext4_msg(sb, KERN_ERR, "can't mount with "
3266                                  "both data=journal and delalloc");
3267                         goto failed_mount;
3268                 }
3269                 if (test_opt(sb, DELALLOC))
3270                         clear_opt(sb, DELALLOC);
3271         }
3272
3273         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3274         if (test_opt(sb, DIOREAD_NOLOCK)) {
3275                 if (blocksize < PAGE_SIZE) {
3276                         ext4_msg(sb, KERN_ERR, "can't mount with "
3277                                  "dioread_nolock if block size != PAGE_SIZE");
3278                         goto failed_mount;
3279                 }
3280         }
3281
3282         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3283                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3284
3285         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3286             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3287              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3288              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3289                 ext4_msg(sb, KERN_WARNING,
3290                        "feature flags set on rev 0 fs, "
3291                        "running e2fsck is recommended");
3292
3293         if (IS_EXT2_SB(sb)) {
3294                 if (ext2_feature_set_ok(sb))
3295                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3296                                  "using the ext4 subsystem");
3297                 else {
3298                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3299                                  "to feature incompatibilities");
3300                         goto failed_mount;
3301                 }
3302         }
3303
3304         if (IS_EXT3_SB(sb)) {
3305                 if (ext3_feature_set_ok(sb))
3306                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3307                                  "using the ext4 subsystem");
3308                 else {
3309                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3310                                  "to feature incompatibilities");
3311                         goto failed_mount;
3312                 }
3313         }
3314
3315         /*
3316          * Check feature flags regardless of the revision level, since we
3317          * previously didn't change the revision level when setting the flags,
3318          * so there is a chance incompat flags are set on a rev 0 filesystem.
3319          */
3320         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3321                 goto failed_mount;
3322
3323         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3324             blocksize > EXT4_MAX_BLOCK_SIZE) {
3325                 ext4_msg(sb, KERN_ERR,
3326                        "Unsupported filesystem blocksize %d", blocksize);
3327                 goto failed_mount;
3328         }
3329
3330         if (sb->s_blocksize != blocksize) {
3331                 /* Validate the filesystem blocksize */
3332                 if (!sb_set_blocksize(sb, blocksize)) {
3333   &nb