0128010a0874e0e558056cd6b74b30cff21f69c8
[muen/linux.git] / fs / ext2 / super.c
1 /*
2  *  linux/fs/ext2/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/slab.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/parser.h>
26 #include <linux/random.h>
27 #include <linux/buffer_head.h>
28 #include <linux/exportfs.h>
29 #include <linux/vfs.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/log2.h>
33 #include <linux/quotaops.h>
34 #include <linux/uaccess.h>
35 #include <linux/dax.h>
36 #include <linux/iversion.h>
37 #include "ext2.h"
38 #include "xattr.h"
39 #include "acl.h"
40
41 static void ext2_write_super(struct super_block *sb);
42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
44 static int ext2_sync_fs(struct super_block *sb, int wait);
45 static int ext2_freeze(struct super_block *sb);
46 static int ext2_unfreeze(struct super_block *sb);
47
48 void ext2_error(struct super_block *sb, const char *function,
49                 const char *fmt, ...)
50 {
51         struct va_format vaf;
52         va_list args;
53         struct ext2_sb_info *sbi = EXT2_SB(sb);
54         struct ext2_super_block *es = sbi->s_es;
55
56         if (!sb_rdonly(sb)) {
57                 spin_lock(&sbi->s_lock);
58                 sbi->s_mount_state |= EXT2_ERROR_FS;
59                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
60                 spin_unlock(&sbi->s_lock);
61                 ext2_sync_super(sb, es, 1);
62         }
63
64         va_start(args, fmt);
65
66         vaf.fmt = fmt;
67         vaf.va = &args;
68
69         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
70                sb->s_id, function, &vaf);
71
72         va_end(args);
73
74         if (test_opt(sb, ERRORS_PANIC))
75                 panic("EXT2-fs: panic from previous error\n");
76         if (!sb_rdonly(sb) && test_opt(sb, ERRORS_RO)) {
77                 ext2_msg(sb, KERN_CRIT,
78                              "error: remounting filesystem read-only");
79                 sb->s_flags |= SB_RDONLY;
80         }
81 }
82
83 void ext2_msg(struct super_block *sb, const char *prefix,
84                 const char *fmt, ...)
85 {
86         struct va_format vaf;
87         va_list args;
88
89         va_start(args, fmt);
90
91         vaf.fmt = fmt;
92         vaf.va = &args;
93
94         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
95
96         va_end(args);
97 }
98
99 /*
100  * This must be called with sbi->s_lock held.
101  */
102 void ext2_update_dynamic_rev(struct super_block *sb)
103 {
104         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
105
106         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
107                 return;
108
109         ext2_msg(sb, KERN_WARNING,
110                      "warning: updating to rev %d because of "
111                      "new feature flag, running e2fsck is recommended",
112                      EXT2_DYNAMIC_REV);
113
114         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
115         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
116         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
117         /* leave es->s_feature_*compat flags alone */
118         /* es->s_uuid will be set by e2fsck if empty */
119
120         /*
121          * The rest of the superblock fields should be zero, and if not it
122          * means they are likely already in use, so leave them alone.  We
123          * can leave it up to e2fsck to clean up any inconsistencies there.
124          */
125 }
126
127 #ifdef CONFIG_QUOTA
128 static int ext2_quota_off(struct super_block *sb, int type);
129
130 static void ext2_quota_off_umount(struct super_block *sb)
131 {
132         int type;
133
134         for (type = 0; type < MAXQUOTAS; type++)
135                 ext2_quota_off(sb, type);
136 }
137 #else
138 static inline void ext2_quota_off_umount(struct super_block *sb)
139 {
140 }
141 #endif
142
143 static void ext2_put_super (struct super_block * sb)
144 {
145         int db_count;
146         int i;
147         struct ext2_sb_info *sbi = EXT2_SB(sb);
148
149         ext2_quota_off_umount(sb);
150
151         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
152         sbi->s_ea_block_cache = NULL;
153
154         if (!sb_rdonly(sb)) {
155                 struct ext2_super_block *es = sbi->s_es;
156
157                 spin_lock(&sbi->s_lock);
158                 es->s_state = cpu_to_le16(sbi->s_mount_state);
159                 spin_unlock(&sbi->s_lock);
160                 ext2_sync_super(sb, es, 1);
161         }
162         db_count = sbi->s_gdb_count;
163         for (i = 0; i < db_count; i++)
164                 if (sbi->s_group_desc[i])
165                         brelse (sbi->s_group_desc[i]);
166         kfree(sbi->s_group_desc);
167         kfree(sbi->s_debts);
168         percpu_counter_destroy(&sbi->s_freeblocks_counter);
169         percpu_counter_destroy(&sbi->s_freeinodes_counter);
170         percpu_counter_destroy(&sbi->s_dirs_counter);
171         brelse (sbi->s_sbh);
172         sb->s_fs_info = NULL;
173         kfree(sbi->s_blockgroup_lock);
174         fs_put_dax(sbi->s_daxdev);
175         kfree(sbi);
176 }
177
178 static struct kmem_cache * ext2_inode_cachep;
179
180 static struct inode *ext2_alloc_inode(struct super_block *sb)
181 {
182         struct ext2_inode_info *ei;
183         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
184         if (!ei)
185                 return NULL;
186         ei->i_block_alloc_info = NULL;
187         inode_set_iversion(&ei->vfs_inode, 1);
188 #ifdef CONFIG_QUOTA
189         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
190 #endif
191
192         return &ei->vfs_inode;
193 }
194
195 static void ext2_i_callback(struct rcu_head *head)
196 {
197         struct inode *inode = container_of(head, struct inode, i_rcu);
198         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
199 }
200
201 static void ext2_destroy_inode(struct inode *inode)
202 {
203         call_rcu(&inode->i_rcu, ext2_i_callback);
204 }
205
206 static void init_once(void *foo)
207 {
208         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
209
210         rwlock_init(&ei->i_meta_lock);
211 #ifdef CONFIG_EXT2_FS_XATTR
212         init_rwsem(&ei->xattr_sem);
213 #endif
214         mutex_init(&ei->truncate_mutex);
215 #ifdef CONFIG_FS_DAX
216         init_rwsem(&ei->dax_sem);
217 #endif
218         inode_init_once(&ei->vfs_inode);
219 }
220
221 static int __init init_inodecache(void)
222 {
223         ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
224                                 sizeof(struct ext2_inode_info), 0,
225                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
226                                         SLAB_ACCOUNT),
227                                 offsetof(struct ext2_inode_info, i_data),
228                                 sizeof_field(struct ext2_inode_info, i_data),
229                                 init_once);
230         if (ext2_inode_cachep == NULL)
231                 return -ENOMEM;
232         return 0;
233 }
234
235 static void destroy_inodecache(void)
236 {
237         /*
238          * Make sure all delayed rcu free inodes are flushed before we
239          * destroy cache.
240          */
241         rcu_barrier();
242         kmem_cache_destroy(ext2_inode_cachep);
243 }
244
245 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
246 {
247         struct super_block *sb = root->d_sb;
248         struct ext2_sb_info *sbi = EXT2_SB(sb);
249         struct ext2_super_block *es = sbi->s_es;
250         unsigned long def_mount_opts;
251
252         spin_lock(&sbi->s_lock);
253         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
254
255         if (sbi->s_sb_block != 1)
256                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
257         if (test_opt(sb, MINIX_DF))
258                 seq_puts(seq, ",minixdf");
259         if (test_opt(sb, GRPID))
260                 seq_puts(seq, ",grpid");
261         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
262                 seq_puts(seq, ",nogrpid");
263         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
264             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
265                 seq_printf(seq, ",resuid=%u",
266                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
267         }
268         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
269             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
270                 seq_printf(seq, ",resgid=%u",
271                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
272         }
273         if (test_opt(sb, ERRORS_RO)) {
274                 int def_errors = le16_to_cpu(es->s_errors);
275
276                 if (def_errors == EXT2_ERRORS_PANIC ||
277                     def_errors == EXT2_ERRORS_CONTINUE) {
278                         seq_puts(seq, ",errors=remount-ro");
279                 }
280         }
281         if (test_opt(sb, ERRORS_CONT))
282                 seq_puts(seq, ",errors=continue");
283         if (test_opt(sb, ERRORS_PANIC))
284                 seq_puts(seq, ",errors=panic");
285         if (test_opt(sb, NO_UID32))
286                 seq_puts(seq, ",nouid32");
287         if (test_opt(sb, DEBUG))
288                 seq_puts(seq, ",debug");
289         if (test_opt(sb, OLDALLOC))
290                 seq_puts(seq, ",oldalloc");
291
292 #ifdef CONFIG_EXT2_FS_XATTR
293         if (test_opt(sb, XATTR_USER))
294                 seq_puts(seq, ",user_xattr");
295         if (!test_opt(sb, XATTR_USER) &&
296             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
297                 seq_puts(seq, ",nouser_xattr");
298         }
299 #endif
300
301 #ifdef CONFIG_EXT2_FS_POSIX_ACL
302         if (test_opt(sb, POSIX_ACL))
303                 seq_puts(seq, ",acl");
304         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
305                 seq_puts(seq, ",noacl");
306 #endif
307
308         if (test_opt(sb, NOBH))
309                 seq_puts(seq, ",nobh");
310
311         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
312                 seq_puts(seq, ",usrquota");
313
314         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
315                 seq_puts(seq, ",grpquota");
316
317         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
318                 seq_puts(seq, ",xip");
319
320         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
321                 seq_puts(seq, ",dax");
322
323         if (!test_opt(sb, RESERVATION))
324                 seq_puts(seq, ",noreservation");
325
326         spin_unlock(&sbi->s_lock);
327         return 0;
328 }
329
330 #ifdef CONFIG_QUOTA
331 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
332 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
333 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
334                          const struct path *path);
335 static struct dquot **ext2_get_dquots(struct inode *inode)
336 {
337         return EXT2_I(inode)->i_dquot;
338 }
339
340 static const struct quotactl_ops ext2_quotactl_ops = {
341         .quota_on       = ext2_quota_on,
342         .quota_off      = ext2_quota_off,
343         .quota_sync     = dquot_quota_sync,
344         .get_state      = dquot_get_state,
345         .set_info       = dquot_set_dqinfo,
346         .get_dqblk      = dquot_get_dqblk,
347         .set_dqblk      = dquot_set_dqblk,
348         .get_nextdqblk  = dquot_get_next_dqblk,
349 };
350 #endif
351
352 static const struct super_operations ext2_sops = {
353         .alloc_inode    = ext2_alloc_inode,
354         .destroy_inode  = ext2_destroy_inode,
355         .write_inode    = ext2_write_inode,
356         .evict_inode    = ext2_evict_inode,
357         .put_super      = ext2_put_super,
358         .sync_fs        = ext2_sync_fs,
359         .freeze_fs      = ext2_freeze,
360         .unfreeze_fs    = ext2_unfreeze,
361         .statfs         = ext2_statfs,
362         .remount_fs     = ext2_remount,
363         .show_options   = ext2_show_options,
364 #ifdef CONFIG_QUOTA
365         .quota_read     = ext2_quota_read,
366         .quota_write    = ext2_quota_write,
367         .get_dquots     = ext2_get_dquots,
368 #endif
369 };
370
371 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
372                 u64 ino, u32 generation)
373 {
374         struct inode *inode;
375
376         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
377                 return ERR_PTR(-ESTALE);
378         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
379                 return ERR_PTR(-ESTALE);
380
381         /*
382          * ext2_iget isn't quite right if the inode is currently unallocated!
383          * However ext2_iget currently does appropriate checks to handle stale
384          * inodes so everything is OK.
385          */
386         inode = ext2_iget(sb, ino);
387         if (IS_ERR(inode))
388                 return ERR_CAST(inode);
389         if (generation && inode->i_generation != generation) {
390                 /* we didn't find the right inode.. */
391                 iput(inode);
392                 return ERR_PTR(-ESTALE);
393         }
394         return inode;
395 }
396
397 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
398                 int fh_len, int fh_type)
399 {
400         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
401                                     ext2_nfs_get_inode);
402 }
403
404 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
405                 int fh_len, int fh_type)
406 {
407         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
408                                     ext2_nfs_get_inode);
409 }
410
411 static const struct export_operations ext2_export_ops = {
412         .fh_to_dentry = ext2_fh_to_dentry,
413         .fh_to_parent = ext2_fh_to_parent,
414         .get_parent = ext2_get_parent,
415 };
416
417 static unsigned long get_sb_block(void **data)
418 {
419         unsigned long   sb_block;
420         char            *options = (char *) *data;
421
422         if (!options || strncmp(options, "sb=", 3) != 0)
423                 return 1;       /* Default location */
424         options += 3;
425         sb_block = simple_strtoul(options, &options, 0);
426         if (*options && *options != ',') {
427                 printk("EXT2-fs: Invalid sb specification: %s\n",
428                        (char *) *data);
429                 return 1;
430         }
431         if (*options == ',')
432                 options++;
433         *data = (void *) options;
434         return sb_block;
435 }
436
437 enum {
438         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
439         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
440         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
441         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
442         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
443         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
444 };
445
446 static const match_table_t tokens = {
447         {Opt_bsd_df, "bsddf"},
448         {Opt_minix_df, "minixdf"},
449         {Opt_grpid, "grpid"},
450         {Opt_grpid, "bsdgroups"},
451         {Opt_nogrpid, "nogrpid"},
452         {Opt_nogrpid, "sysvgroups"},
453         {Opt_resgid, "resgid=%u"},
454         {Opt_resuid, "resuid=%u"},
455         {Opt_sb, "sb=%u"},
456         {Opt_err_cont, "errors=continue"},
457         {Opt_err_panic, "errors=panic"},
458         {Opt_err_ro, "errors=remount-ro"},
459         {Opt_nouid32, "nouid32"},
460         {Opt_nocheck, "check=none"},
461         {Opt_nocheck, "nocheck"},
462         {Opt_debug, "debug"},
463         {Opt_oldalloc, "oldalloc"},
464         {Opt_orlov, "orlov"},
465         {Opt_nobh, "nobh"},
466         {Opt_user_xattr, "user_xattr"},
467         {Opt_nouser_xattr, "nouser_xattr"},
468         {Opt_acl, "acl"},
469         {Opt_noacl, "noacl"},
470         {Opt_xip, "xip"},
471         {Opt_dax, "dax"},
472         {Opt_grpquota, "grpquota"},
473         {Opt_ignore, "noquota"},
474         {Opt_quota, "quota"},
475         {Opt_usrquota, "usrquota"},
476         {Opt_reservation, "reservation"},
477         {Opt_noreservation, "noreservation"},
478         {Opt_err, NULL}
479 };
480
481 static int parse_options(char *options, struct super_block *sb,
482                          struct ext2_mount_options *opts)
483 {
484         char *p;
485         substring_t args[MAX_OPT_ARGS];
486         int option;
487         kuid_t uid;
488         kgid_t gid;
489
490         if (!options)
491                 return 1;
492
493         while ((p = strsep (&options, ",")) != NULL) {
494                 int token;
495                 if (!*p)
496                         continue;
497
498                 token = match_token(p, tokens, args);
499                 switch (token) {
500                 case Opt_bsd_df:
501                         clear_opt (opts->s_mount_opt, MINIX_DF);
502                         break;
503                 case Opt_minix_df:
504                         set_opt (opts->s_mount_opt, MINIX_DF);
505                         break;
506                 case Opt_grpid:
507                         set_opt (opts->s_mount_opt, GRPID);
508                         break;
509                 case Opt_nogrpid:
510                         clear_opt (opts->s_mount_opt, GRPID);
511                         break;
512                 case Opt_resuid:
513                         if (match_int(&args[0], &option))
514                                 return 0;
515                         uid = make_kuid(current_user_ns(), option);
516                         if (!uid_valid(uid)) {
517                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
518                                 return 0;
519
520                         }
521                         opts->s_resuid = uid;
522                         break;
523                 case Opt_resgid:
524                         if (match_int(&args[0], &option))
525                                 return 0;
526                         gid = make_kgid(current_user_ns(), option);
527                         if (!gid_valid(gid)) {
528                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
529                                 return 0;
530                         }
531                         opts->s_resgid = gid;
532                         break;
533                 case Opt_sb:
534                         /* handled by get_sb_block() instead of here */
535                         /* *sb_block = match_int(&args[0]); */
536                         break;
537                 case Opt_err_panic:
538                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
539                         clear_opt (opts->s_mount_opt, ERRORS_RO);
540                         set_opt (opts->s_mount_opt, ERRORS_PANIC);
541                         break;
542                 case Opt_err_ro:
543                         clear_opt (opts->s_mount_opt, ERRORS_CONT);
544                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
545                         set_opt (opts->s_mount_opt, ERRORS_RO);
546                         break;
547                 case Opt_err_cont:
548                         clear_opt (opts->s_mount_opt, ERRORS_RO);
549                         clear_opt (opts->s_mount_opt, ERRORS_PANIC);
550                         set_opt (opts->s_mount_opt, ERRORS_CONT);
551                         break;
552                 case Opt_nouid32:
553                         set_opt (opts->s_mount_opt, NO_UID32);
554                         break;
555                 case Opt_nocheck:
556                         ext2_msg(sb, KERN_WARNING,
557                                 "Option nocheck/check=none is deprecated and"
558                                 " will be removed in June 2020.");
559                         clear_opt (opts->s_mount_opt, CHECK);
560                         break;
561                 case Opt_debug:
562                         set_opt (opts->s_mount_opt, DEBUG);
563                         break;
564                 case Opt_oldalloc:
565                         set_opt (opts->s_mount_opt, OLDALLOC);
566                         break;
567                 case Opt_orlov:
568                         clear_opt (opts->s_mount_opt, OLDALLOC);
569                         break;
570                 case Opt_nobh:
571                         set_opt (opts->s_mount_opt, NOBH);
572                         break;
573 #ifdef CONFIG_EXT2_FS_XATTR
574                 case Opt_user_xattr:
575                         set_opt (opts->s_mount_opt, XATTR_USER);
576                         break;
577                 case Opt_nouser_xattr:
578                         clear_opt (opts->s_mount_opt, XATTR_USER);
579                         break;
580 #else
581                 case Opt_user_xattr:
582                 case Opt_nouser_xattr:
583                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
584                                 "not supported");
585                         break;
586 #endif
587 #ifdef CONFIG_EXT2_FS_POSIX_ACL
588                 case Opt_acl:
589                         set_opt(opts->s_mount_opt, POSIX_ACL);
590                         break;
591                 case Opt_noacl:
592                         clear_opt(opts->s_mount_opt, POSIX_ACL);
593                         break;
594 #else
595                 case Opt_acl:
596                 case Opt_noacl:
597                         ext2_msg(sb, KERN_INFO,
598                                 "(no)acl options not supported");
599                         break;
600 #endif
601                 case Opt_xip:
602                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
603                         set_opt(opts->s_mount_opt, XIP);
604                         /* Fall through */
605                 case Opt_dax:
606 #ifdef CONFIG_FS_DAX
607                         ext2_msg(sb, KERN_WARNING,
608                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
609                         set_opt(opts->s_mount_opt, DAX);
610 #else
611                         ext2_msg(sb, KERN_INFO, "dax option not supported");
612 #endif
613                         break;
614
615 #if defined(CONFIG_QUOTA)
616                 case Opt_quota:
617                 case Opt_usrquota:
618                         set_opt(opts->s_mount_opt, USRQUOTA);
619                         break;
620
621                 case Opt_grpquota:
622                         set_opt(opts->s_mount_opt, GRPQUOTA);
623                         break;
624 #else
625                 case Opt_quota:
626                 case Opt_usrquota:
627                 case Opt_grpquota:
628                         ext2_msg(sb, KERN_INFO,
629                                 "quota operations not supported");
630                         break;
631 #endif
632
633                 case Opt_reservation:
634                         set_opt(opts->s_mount_opt, RESERVATION);
635                         ext2_msg(sb, KERN_INFO, "reservations ON");
636                         break;
637                 case Opt_noreservation:
638                         clear_opt(opts->s_mount_opt, RESERVATION);
639                         ext2_msg(sb, KERN_INFO, "reservations OFF");
640                         break;
641                 case Opt_ignore:
642                         break;
643                 default:
644                         return 0;
645                 }
646         }
647         return 1;
648 }
649
650 static int ext2_setup_super (struct super_block * sb,
651                               struct ext2_super_block * es,
652                               int read_only)
653 {
654         int res = 0;
655         struct ext2_sb_info *sbi = EXT2_SB(sb);
656
657         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
658                 ext2_msg(sb, KERN_ERR,
659                         "error: revision level too high, "
660                         "forcing read-only mode");
661                 res = SB_RDONLY;
662         }
663         if (read_only)
664                 return res;
665         if (!(sbi->s_mount_state & EXT2_VALID_FS))
666                 ext2_msg(sb, KERN_WARNING,
667                         "warning: mounting unchecked fs, "
668                         "running e2fsck is recommended");
669         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
670                 ext2_msg(sb, KERN_WARNING,
671                         "warning: mounting fs with errors, "
672                         "running e2fsck is recommended");
673         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
674                  le16_to_cpu(es->s_mnt_count) >=
675                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
676                 ext2_msg(sb, KERN_WARNING,
677                         "warning: maximal mount count reached, "
678                         "running e2fsck is recommended");
679         else if (le32_to_cpu(es->s_checkinterval) &&
680                 (le32_to_cpu(es->s_lastcheck) +
681                         le32_to_cpu(es->s_checkinterval) <=
682                         ktime_get_real_seconds()))
683                 ext2_msg(sb, KERN_WARNING,
684                         "warning: checktime reached, "
685                         "running e2fsck is recommended");
686         if (!le16_to_cpu(es->s_max_mnt_count))
687                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
688         le16_add_cpu(&es->s_mnt_count, 1);
689         if (test_opt (sb, DEBUG))
690                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
691                         "bpg=%lu, ipg=%lu, mo=%04lx]",
692                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
693                         sbi->s_frag_size,
694                         sbi->s_groups_count,
695                         EXT2_BLOCKS_PER_GROUP(sb),
696                         EXT2_INODES_PER_GROUP(sb),
697                         sbi->s_mount_opt);
698         return res;
699 }
700
701 static int ext2_check_descriptors(struct super_block *sb)
702 {
703         int i;
704         struct ext2_sb_info *sbi = EXT2_SB(sb);
705
706         ext2_debug ("Checking group descriptors");
707
708         for (i = 0; i < sbi->s_groups_count; i++) {
709                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
710                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
711                 ext2_fsblk_t last_block;
712
713                 if (i == sbi->s_groups_count - 1)
714                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
715                 else
716                         last_block = first_block +
717                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
718
719                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
720                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
721                 {
722                         ext2_error (sb, "ext2_check_descriptors",
723                                     "Block bitmap for group %d"
724                                     " not in group (block %lu)!",
725                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
726                         return 0;
727                 }
728                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
729                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
730                 {
731                         ext2_error (sb, "ext2_check_descriptors",
732                                     "Inode bitmap for group %d"
733                                     " not in group (block %lu)!",
734                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
735                         return 0;
736                 }
737                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
738                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
739                     last_block)
740                 {
741                         ext2_error (sb, "ext2_check_descriptors",
742                                     "Inode table for group %d"
743                                     " not in group (block %lu)!",
744                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
745                         return 0;
746                 }
747         }
748         return 1;
749 }
750
751 /*
752  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
753  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
754  * We need to be 1 filesystem block less than the 2^32 sector limit.
755  */
756 static loff_t ext2_max_size(int bits)
757 {
758         loff_t res = EXT2_NDIR_BLOCKS;
759         int meta_blocks;
760         unsigned int upper_limit;
761         unsigned int ppb = 1 << (bits-2);
762
763         /* This is calculated to be the largest file size for a
764          * dense, file such that the total number of
765          * sectors in the file, including data and all indirect blocks,
766          * does not exceed 2^32 -1
767          * __u32 i_blocks representing the total number of
768          * 512 bytes blocks of the file
769          */
770         upper_limit = (1LL << 32) - 1;
771
772         /* total blocks in file system block size */
773         upper_limit >>= (bits - 9);
774
775         /* Compute how many blocks we can address by block tree */
776         res += 1LL << (bits-2);
777         res += 1LL << (2*(bits-2));
778         res += 1LL << (3*(bits-2));
779         /* Does block tree limit file size? */
780         if (res < upper_limit)
781                 goto check_lfs;
782
783         res = upper_limit;
784         /* How many metadata blocks are needed for addressing upper_limit? */
785         upper_limit -= EXT2_NDIR_BLOCKS;
786         /* indirect blocks */
787         meta_blocks = 1;
788         upper_limit -= ppb;
789         /* double indirect blocks */
790         if (upper_limit < ppb * ppb) {
791                 meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
792                 res -= meta_blocks;
793                 goto check_lfs;
794         }
795         meta_blocks += 1 + ppb;
796         upper_limit -= ppb * ppb;
797         /* tripple indirect blocks for the rest */
798         meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
799                 DIV_ROUND_UP(upper_limit, ppb*ppb);
800         res -= meta_blocks;
801 check_lfs:
802         res <<= bits;
803         if (res > MAX_LFS_FILESIZE)
804                 res = MAX_LFS_FILESIZE;
805
806         return res;
807 }
808
809 static unsigned long descriptor_loc(struct super_block *sb,
810                                     unsigned long logic_sb_block,
811                                     int nr)
812 {
813         struct ext2_sb_info *sbi = EXT2_SB(sb);
814         unsigned long bg, first_meta_bg;
815         int has_super = 0;
816         
817         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
818
819         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
820             nr < first_meta_bg)
821                 return (logic_sb_block + nr + 1);
822         bg = sbi->s_desc_per_block * nr;
823         if (ext2_bg_has_super(sb, bg))
824                 has_super = 1;
825
826         return ext2_group_first_block_no(sb, bg) + has_super;
827 }
828
829 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
830 {
831         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
832         struct buffer_head * bh;
833         struct ext2_sb_info * sbi;
834         struct ext2_super_block * es;
835         struct inode *root;
836         unsigned long block;
837         unsigned long sb_block = get_sb_block(&data);
838         unsigned long logic_sb_block;
839         unsigned long offset = 0;
840         unsigned long def_mount_opts;
841         long ret = -ENOMEM;
842         int blocksize = BLOCK_SIZE;
843         int db_count;
844         int i, j;
845         __le32 features;
846         int err;
847         struct ext2_mount_options opts;
848
849         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
850         if (!sbi)
851                 goto failed;
852
853         sbi->s_blockgroup_lock =
854                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
855         if (!sbi->s_blockgroup_lock) {
856                 kfree(sbi);
857                 goto failed;
858         }
859         sb->s_fs_info = sbi;
860         sbi->s_sb_block = sb_block;
861         sbi->s_daxdev = dax_dev;
862
863         spin_lock_init(&sbi->s_lock);
864         ret = -EINVAL;
865
866         /*
867          * See what the current blocksize for the device is, and
868          * use that as the blocksize.  Otherwise (or if the blocksize
869          * is smaller than the default) use the default.
870          * This is important for devices that have a hardware
871          * sectorsize that is larger than the default.
872          */
873         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
874         if (!blocksize) {
875                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
876                 goto failed_sbi;
877         }
878
879         /*
880          * If the superblock doesn't start on a hardware sector boundary,
881          * calculate the offset.  
882          */
883         if (blocksize != BLOCK_SIZE) {
884                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
885                 offset = (sb_block*BLOCK_SIZE) % blocksize;
886         } else {
887                 logic_sb_block = sb_block;
888         }
889
890         if (!(bh = sb_bread(sb, logic_sb_block))) {
891                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
892                 goto failed_sbi;
893         }
894         /*
895          * Note: s_es must be initialized as soon as possible because
896          *       some ext2 macro-instructions depend on its value
897          */
898         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
899         sbi->s_es = es;
900         sb->s_magic = le16_to_cpu(es->s_magic);
901
902         if (sb->s_magic != EXT2_SUPER_MAGIC)
903                 goto cantfind_ext2;
904
905         opts.s_mount_opt = 0;
906         /* Set defaults before we parse the mount options */
907         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
908         if (def_mount_opts & EXT2_DEFM_DEBUG)
909                 set_opt(opts.s_mount_opt, DEBUG);
910         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
911                 set_opt(opts.s_mount_opt, GRPID);
912         if (def_mount_opts & EXT2_DEFM_UID16)
913                 set_opt(opts.s_mount_opt, NO_UID32);
914 #ifdef CONFIG_EXT2_FS_XATTR
915         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
916                 set_opt(opts.s_mount_opt, XATTR_USER);
917 #endif
918 #ifdef CONFIG_EXT2_FS_POSIX_ACL
919         if (def_mount_opts & EXT2_DEFM_ACL)
920                 set_opt(opts.s_mount_opt, POSIX_ACL);
921 #endif
922         
923         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
924                 set_opt(opts.s_mount_opt, ERRORS_PANIC);
925         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
926                 set_opt(opts.s_mount_opt, ERRORS_CONT);
927         else
928                 set_opt(opts.s_mount_opt, ERRORS_RO);
929
930         opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
931         opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
932         
933         set_opt(opts.s_mount_opt, RESERVATION);
934
935         if (!parse_options((char *) data, sb, &opts))
936                 goto failed_mount;
937
938         sbi->s_mount_opt = opts.s_mount_opt;
939         sbi->s_resuid = opts.s_resuid;
940         sbi->s_resgid = opts.s_resgid;
941
942         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
943                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
944                  SB_POSIXACL : 0);
945         sb->s_iflags |= SB_I_CGROUPWB;
946
947         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
948             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
949              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
950              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
951                 ext2_msg(sb, KERN_WARNING,
952                         "warning: feature flags set on rev 0 fs, "
953                         "running e2fsck is recommended");
954         /*
955          * Check feature flags regardless of the revision level, since we
956          * previously didn't change the revision level when setting the flags,
957          * so there is a chance incompat flags are set on a rev 0 filesystem.
958          */
959         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
960         if (features) {
961                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
962                        "unsupported optional features (%x)",
963                         le32_to_cpu(features));
964                 goto failed_mount;
965         }
966         if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
967                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
968                        "unsupported optional features (%x)",
969                        le32_to_cpu(features));
970                 goto failed_mount;
971         }
972
973         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
974
975         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
976                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
977                         ext2_msg(sb, KERN_ERR,
978                                 "DAX unsupported by block device. Turning off DAX.");
979                         sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
980                 }
981         }
982
983         /* If the blocksize doesn't match, re-read the thing.. */
984         if (sb->s_blocksize != blocksize) {
985                 brelse(bh);
986
987                 if (!sb_set_blocksize(sb, blocksize)) {
988                         ext2_msg(sb, KERN_ERR,
989                                 "error: bad blocksize %d", blocksize);
990                         goto failed_sbi;
991                 }
992
993                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
994                 offset = (sb_block*BLOCK_SIZE) % blocksize;
995                 bh = sb_bread(sb, logic_sb_block);
996                 if(!bh) {
997                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
998                                 "superblock on 2nd try");
999                         goto failed_sbi;
1000                 }
1001                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
1002                 sbi->s_es = es;
1003                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
1004                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
1005                         goto failed_mount;
1006                 }
1007         }
1008
1009         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
1010         sb->s_max_links = EXT2_LINK_MAX;
1011
1012         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1013                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1014                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1015         } else {
1016                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1017                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1018                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1019                     !is_power_of_2(sbi->s_inode_size) ||
1020                     (sbi->s_inode_size > blocksize)) {
1021                         ext2_msg(sb, KERN_ERR,
1022                                 "error: unsupported inode size: %d",
1023                                 sbi->s_inode_size);
1024                         goto failed_mount;
1025                 }
1026         }
1027
1028         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1029                                    le32_to_cpu(es->s_log_frag_size);
1030         if (sbi->s_frag_size == 0)
1031                 goto cantfind_ext2;
1032         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1033
1034         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1035         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1036         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1037
1038         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1039         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1040                 goto cantfind_ext2;
1041         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1042                                         sbi->s_inodes_per_block;
1043         sbi->s_desc_per_block = sb->s_blocksize /
1044                                         sizeof (struct ext2_group_desc);
1045         sbi->s_sbh = bh;
1046         sbi->s_mount_state = le16_to_cpu(es->s_state);
1047         sbi->s_addr_per_block_bits =
1048                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1049         sbi->s_desc_per_block_bits =
1050                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1051
1052         if (sb->s_magic != EXT2_SUPER_MAGIC)
1053                 goto cantfind_ext2;
1054
1055         if (sb->s_blocksize != bh->b_size) {
1056                 if (!silent)
1057                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1058                 goto failed_mount;
1059         }
1060
1061         if (sb->s_blocksize != sbi->s_frag_size) {
1062                 ext2_msg(sb, KERN_ERR,
1063                         "error: fragsize %lu != blocksize %lu"
1064                         "(not supported yet)",
1065                         sbi->s_frag_size, sb->s_blocksize);
1066                 goto failed_mount;
1067         }
1068
1069         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1070                 ext2_msg(sb, KERN_ERR,
1071                         "error: #blocks per group too big: %lu",
1072                         sbi->s_blocks_per_group);
1073                 goto failed_mount;
1074         }
1075         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1076                 ext2_msg(sb, KERN_ERR,
1077                         "error: #fragments per group too big: %lu",
1078                         sbi->s_frags_per_group);
1079                 goto failed_mount;
1080         }
1081         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1082                 ext2_msg(sb, KERN_ERR,
1083                         "error: #inodes per group too big: %lu",
1084                         sbi->s_inodes_per_group);
1085                 goto failed_mount;
1086         }
1087
1088         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1089                 goto cantfind_ext2;
1090         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1091                                 le32_to_cpu(es->s_first_data_block) - 1)
1092                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1093         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1094                    EXT2_DESC_PER_BLOCK(sb);
1095         sbi->s_group_desc = kmalloc_array (db_count,
1096                                            sizeof(struct buffer_head *),
1097                                            GFP_KERNEL);
1098         if (sbi->s_group_desc == NULL) {
1099                 ret = -ENOMEM;
1100                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1101                 goto failed_mount;
1102         }
1103         bgl_lock_init(sbi->s_blockgroup_lock);
1104         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1105         if (!sbi->s_debts) {
1106                 ret = -ENOMEM;
1107                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1108                 goto failed_mount_group_desc;
1109         }
1110         for (i = 0; i < db_count; i++) {
1111                 block = descriptor_loc(sb, logic_sb_block, i);
1112                 sbi->s_group_desc[i] = sb_bread(sb, block);
1113                 if (!sbi->s_group_desc[i]) {
1114                         for (j = 0; j < i; j++)
1115                                 brelse (sbi->s_group_desc[j]);
1116                         ext2_msg(sb, KERN_ERR,
1117                                 "error: unable to read group descriptors");
1118                         goto failed_mount_group_desc;
1119                 }
1120         }
1121         if (!ext2_check_descriptors (sb)) {
1122                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1123                 goto failed_mount2;
1124         }
1125         sbi->s_gdb_count = db_count;
1126         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1127         spin_lock_init(&sbi->s_next_gen_lock);
1128
1129         /* per fileystem reservation list head & lock */
1130         spin_lock_init(&sbi->s_rsv_window_lock);
1131         sbi->s_rsv_window_root = RB_ROOT;
1132         /*
1133          * Add a single, static dummy reservation to the start of the
1134          * reservation window list --- it gives us a placeholder for
1135          * append-at-start-of-list which makes the allocation logic
1136          * _much_ simpler.
1137          */
1138         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1139         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1140         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1141         sbi->s_rsv_window_head.rsv_goal_size = 0;
1142         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1143
1144         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1145                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1146         if (!err) {
1147                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1148                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1149         }
1150         if (!err) {
1151                 err = percpu_counter_init(&sbi->s_dirs_counter,
1152                                 ext2_count_dirs(sb), GFP_KERNEL);
1153         }
1154         if (err) {
1155                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1156                 goto failed_mount3;
1157         }
1158
1159 #ifdef CONFIG_EXT2_FS_XATTR
1160         sbi->s_ea_block_cache = ext2_xattr_create_cache();
1161         if (!sbi->s_ea_block_cache) {
1162                 ret = -ENOMEM;
1163                 ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1164                 goto failed_mount3;
1165         }
1166 #endif
1167         /*
1168          * set up enough so that it can read an inode
1169          */
1170         sb->s_op = &ext2_sops;
1171         sb->s_export_op = &ext2_export_ops;
1172         sb->s_xattr = ext2_xattr_handlers;
1173
1174 #ifdef CONFIG_QUOTA
1175         sb->dq_op = &dquot_operations;
1176         sb->s_qcop = &ext2_quotactl_ops;
1177         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1178 #endif
1179
1180         root = ext2_iget(sb, EXT2_ROOT_INO);
1181         if (IS_ERR(root)) {
1182                 ret = PTR_ERR(root);
1183                 goto failed_mount3;
1184         }
1185         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1186                 iput(root);
1187                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1188                 goto failed_mount3;
1189         }
1190
1191         sb->s_root = d_make_root(root);
1192         if (!sb->s_root) {
1193                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1194                 ret = -ENOMEM;
1195                 goto failed_mount3;
1196         }
1197         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1198                 ext2_msg(sb, KERN_WARNING,
1199                         "warning: mounting ext3 filesystem as ext2");
1200         if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1201                 sb->s_flags |= SB_RDONLY;
1202         ext2_write_super(sb);
1203         return 0;
1204
1205 cantfind_ext2:
1206         if (!silent)
1207                 ext2_msg(sb, KERN_ERR,
1208                         "error: can't find an ext2 filesystem on dev %s.",
1209                         sb->s_id);
1210         goto failed_mount;
1211 failed_mount3:
1212         ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1213         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1214         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1215         percpu_counter_destroy(&sbi->s_dirs_counter);
1216 failed_mount2:
1217         for (i = 0; i < db_count; i++)
1218                 brelse(sbi->s_group_desc[i]);
1219 failed_mount_group_desc:
1220         kfree(sbi->s_group_desc);
1221         kfree(sbi->s_debts);
1222 failed_mount:
1223         brelse(bh);
1224 failed_sbi:
1225         sb->s_fs_info = NULL;
1226         kfree(sbi->s_blockgroup_lock);
1227         kfree(sbi);
1228 failed:
1229         fs_put_dax(dax_dev);
1230         return ret;
1231 }
1232
1233 static void ext2_clear_super_error(struct super_block *sb)
1234 {
1235         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1236
1237         if (buffer_write_io_error(sbh)) {
1238                 /*
1239                  * Oh, dear.  A previous attempt to write the
1240                  * superblock failed.  This could happen because the
1241                  * USB device was yanked out.  Or it could happen to
1242                  * be a transient write error and maybe the block will
1243                  * be remapped.  Nothing we can do but to retry the
1244                  * write and hope for the best.
1245                  */
1246                 ext2_msg(sb, KERN_ERR,
1247                        "previous I/O error to superblock detected");
1248                 clear_buffer_write_io_error(sbh);
1249                 set_buffer_uptodate(sbh);
1250         }
1251 }
1252
1253 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1254                      int wait)
1255 {
1256         ext2_clear_super_error(sb);
1257         spin_lock(&EXT2_SB(sb)->s_lock);
1258         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1259         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1260         es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
1261         /* unlock before we do IO */
1262         spin_unlock(&EXT2_SB(sb)->s_lock);
1263         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1264         if (wait)
1265                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1266 }
1267
1268 /*
1269  * In the second extended file system, it is not necessary to
1270  * write the super block since we use a mapping of the
1271  * disk super block in a buffer.
1272  *
1273  * However, this function is still used to set the fs valid
1274  * flags to 0.  We need to set this flag to 0 since the fs
1275  * may have been checked while mounted and e2fsck may have
1276  * set s_state to EXT2_VALID_FS after some corrections.
1277  */
1278 static int ext2_sync_fs(struct super_block *sb, int wait)
1279 {
1280         struct ext2_sb_info *sbi = EXT2_SB(sb);
1281         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1282
1283         /*
1284          * Write quota structures to quota file, sync_blockdev() will write
1285          * them to disk later
1286          */
1287         dquot_writeback_dquots(sb, -1);
1288
1289         spin_lock(&sbi->s_lock);
1290         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1291                 ext2_debug("setting valid to 0\n");
1292                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1293         }
1294         spin_unlock(&sbi->s_lock);
1295         ext2_sync_super(sb, es, wait);
1296         return 0;
1297 }
1298
1299 static int ext2_freeze(struct super_block *sb)
1300 {
1301         struct ext2_sb_info *sbi = EXT2_SB(sb);
1302
1303         /*
1304          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1305          * because we have unattached inodes and thus filesystem is not fully
1306          * consistent.
1307          */
1308         if (atomic_long_read(&sb->s_remove_count)) {
1309                 ext2_sync_fs(sb, 1);
1310                 return 0;
1311         }
1312         /* Set EXT2_FS_VALID flag */
1313         spin_lock(&sbi->s_lock);
1314         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1315         spin_unlock(&sbi->s_lock);
1316         ext2_sync_super(sb, sbi->s_es, 1);
1317
1318         return 0;
1319 }
1320
1321 static int ext2_unfreeze(struct super_block *sb)
1322 {
1323         /* Just write sb to clear EXT2_VALID_FS flag */
1324         ext2_write_super(sb);
1325
1326         return 0;
1327 }
1328
1329 static void ext2_write_super(struct super_block *sb)
1330 {
1331         if (!sb_rdonly(sb))
1332                 ext2_sync_fs(sb, 1);
1333 }
1334
1335 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1336 {
1337         struct ext2_sb_info * sbi = EXT2_SB(sb);
1338         struct ext2_super_block * es;
1339         struct ext2_mount_options new_opts;
1340         int err;
1341
1342         sync_filesystem(sb);
1343
1344         spin_lock(&sbi->s_lock);
1345         new_opts.s_mount_opt = sbi->s_mount_opt;
1346         new_opts.s_resuid = sbi->s_resuid;
1347         new_opts.s_resgid = sbi->s_resgid;
1348         spin_unlock(&sbi->s_lock);
1349
1350         if (!parse_options(data, sb, &new_opts))
1351                 return -EINVAL;
1352
1353         spin_lock(&sbi->s_lock);
1354         es = sbi->s_es;
1355         if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1356                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1357                          "dax flag with busy inodes while remounting");
1358                 new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1359         }
1360         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1361                 goto out_set;
1362         if (*flags & SB_RDONLY) {
1363                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1364                     !(sbi->s_mount_state & EXT2_VALID_FS))
1365                         goto out_set;
1366
1367                 /*
1368                  * OK, we are remounting a valid rw partition rdonly, so set
1369                  * the rdonly flag and then mark the partition as valid again.
1370                  */
1371                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1372                 es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
1373                 spin_unlock(&sbi->s_lock);
1374
1375                 err = dquot_suspend(sb, -1);
1376                 if (err < 0)
1377                         return err;
1378
1379                 ext2_sync_super(sb, es, 1);
1380         } else {
1381                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1382                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1383                 if (ret) {
1384                         spin_unlock(&sbi->s_lock);
1385                         ext2_msg(sb, KERN_WARNING,
1386                                 "warning: couldn't remount RDWR because of "
1387                                 "unsupported optional features (%x).",
1388                                 le32_to_cpu(ret));
1389                         return -EROFS;
1390                 }
1391                 /*
1392                  * Mounting a RDONLY partition read-write, so reread and
1393                  * store the current valid flag.  (It may have been changed
1394                  * by e2fsck since we originally mounted the partition.)
1395                  */
1396                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1397                 if (!ext2_setup_super (sb, es, 0))
1398                         sb->s_flags &= ~SB_RDONLY;
1399                 spin_unlock(&sbi->s_lock);
1400
1401                 ext2_write_super(sb);
1402
1403                 dquot_resume(sb, -1);
1404         }
1405
1406         spin_lock(&sbi->s_lock);
1407 out_set:
1408         sbi->s_mount_opt = new_opts.s_mount_opt;
1409         sbi->s_resuid = new_opts.s_resuid;
1410         sbi->s_resgid = new_opts.s_resgid;
1411         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1412                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
1413         spin_unlock(&sbi->s_lock);
1414
1415         return 0;
1416 }
1417
1418 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1419 {
1420         struct super_block *sb = dentry->d_sb;
1421         struct ext2_sb_info *sbi = EXT2_SB(sb);
1422         struct ext2_super_block *es = sbi->s_es;
1423         u64 fsid;
1424
1425         spin_lock(&sbi->s_lock);
1426
1427         if (test_opt (sb, MINIX_DF))
1428                 sbi->s_overhead_last = 0;
1429         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1430                 unsigned long i, overhead = 0;
1431                 smp_rmb();
1432
1433                 /*
1434                  * Compute the overhead (FS structures). This is constant
1435                  * for a given filesystem unless the number of block groups
1436                  * changes so we cache the previous value until it does.
1437                  */
1438
1439                 /*
1440                  * All of the blocks before first_data_block are
1441                  * overhead
1442                  */
1443                 overhead = le32_to_cpu(es->s_first_data_block);
1444
1445                 /*
1446                  * Add the overhead attributed to the superblock and
1447                  * block group descriptors.  If the sparse superblocks
1448                  * feature is turned on, then not all groups have this.
1449                  */
1450                 for (i = 0; i < sbi->s_groups_count; i++)
1451                         overhead += ext2_bg_has_super(sb, i) +
1452                                 ext2_bg_num_gdb(sb, i);
1453
1454                 /*
1455                  * Every block group has an inode bitmap, a block
1456                  * bitmap, and an inode table.
1457                  */
1458                 overhead += (sbi->s_groups_count *
1459                              (2 + sbi->s_itb_per_group));
1460                 sbi->s_overhead_last = overhead;
1461                 smp_wmb();
1462                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1463         }
1464
1465         buf->f_type = EXT2_SUPER_MAGIC;
1466         buf->f_bsize = sb->s_blocksize;
1467         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1468         buf->f_bfree = ext2_count_free_blocks(sb);
1469         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1470         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1471         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1472                 buf->f_bavail = 0;
1473         buf->f_files = le32_to_cpu(es->s_inodes_count);
1474         buf->f_ffree = ext2_count_free_inodes(sb);
1475         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1476         buf->f_namelen = EXT2_NAME_LEN;
1477         fsid = le64_to_cpup((void *)es->s_uuid) ^
1478                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1479         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1480         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1481         spin_unlock(&sbi->s_lock);
1482         return 0;
1483 }
1484
1485 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1486         int flags, const char *dev_name, void *data)
1487 {
1488         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1489 }
1490
1491 #ifdef CONFIG_QUOTA
1492
1493 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1494  * acquiring the locks... As quota files are never truncated and quota code
1495  * itself serializes the operations (and no one else should touch the files)
1496  * we don't have to be afraid of races */
1497 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1498                                size_t len, loff_t off)
1499 {
1500         struct inode *inode = sb_dqopt(sb)->files[type];
1501         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1502         int err = 0;
1503         int offset = off & (sb->s_blocksize - 1);
1504         int tocopy;
1505         size_t toread;
1506         struct buffer_head tmp_bh;
1507         struct buffer_head *bh;
1508         loff_t i_size = i_size_read(inode);
1509
1510         if (off > i_size)
1511                 return 0;
1512         if (off+len > i_size)
1513                 len = i_size-off;
1514         toread = len;
1515         while (toread > 0) {
1516                 tocopy = sb->s_blocksize - offset < toread ?
1517                                 sb->s_blocksize - offset : toread;
1518
1519                 tmp_bh.b_state = 0;
1520                 tmp_bh.b_size = sb->s_blocksize;
1521                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1522                 if (err < 0)
1523                         return err;
1524                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1525                         memset(data, 0, tocopy);
1526                 else {
1527                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1528                         if (!bh)
1529                                 return -EIO;
1530                         memcpy(data, bh->b_data+offset, tocopy);
1531                         brelse(bh);
1532                 }
1533                 offset = 0;
1534                 toread -= tocopy;
1535                 data += tocopy;
1536                 blk++;
1537         }
1538         return len;
1539 }
1540
1541 /* Write to quotafile */
1542 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1543                                 const char *data, size_t len, loff_t off)
1544 {
1545         struct inode *inode = sb_dqopt(sb)->files[type];
1546         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1547         int err = 0;
1548         int offset = off & (sb->s_blocksize - 1);
1549         int tocopy;
1550         size_t towrite = len;
1551         struct buffer_head tmp_bh;
1552         struct buffer_head *bh;
1553
1554         while (towrite > 0) {
1555                 tocopy = sb->s_blocksize - offset < towrite ?
1556                                 sb->s_blocksize - offset : towrite;
1557
1558                 tmp_bh.b_state = 0;
1559                 tmp_bh.b_size = sb->s_blocksize;
1560                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1561                 if (err < 0)
1562                         goto out;
1563                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1564                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1565                 else
1566                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1567                 if (unlikely(!bh)) {
1568                         err = -EIO;
1569                         goto out;
1570                 }
1571                 lock_buffer(bh);
1572                 memcpy(bh->b_data+offset, data, tocopy);
1573                 flush_dcache_page(bh->b_page);
1574                 set_buffer_uptodate(bh);
1575                 mark_buffer_dirty(bh);
1576                 unlock_buffer(bh);
1577                 brelse(bh);
1578                 offset = 0;
1579                 towrite -= tocopy;
1580                 data += tocopy;
1581                 blk++;
1582         }
1583 out:
1584         if (len == towrite)
1585                 return err;
1586         if (inode->i_size < off+len-towrite)
1587                 i_size_write(inode, off+len-towrite);
1588         inode_inc_iversion(inode);
1589         inode->i_mtime = inode->i_ctime = current_time(inode);
1590         mark_inode_dirty(inode);
1591         return len - towrite;
1592 }
1593
1594 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1595                          const struct path *path)
1596 {
1597         int err;
1598         struct inode *inode;
1599
1600         err = dquot_quota_on(sb, type, format_id, path);
1601         if (err)
1602                 return err;
1603
1604         inode = d_inode(path->dentry);
1605         inode_lock(inode);
1606         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1607         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1608                         S_NOATIME | S_IMMUTABLE);
1609         inode_unlock(inode);
1610         mark_inode_dirty(inode);
1611
1612         return 0;
1613 }
1614
1615 static int ext2_quota_off(struct super_block *sb, int type)
1616 {
1617         struct inode *inode = sb_dqopt(sb)->files[type];
1618         int err;
1619
1620         if (!inode || !igrab(inode))
1621                 goto out;
1622
1623         err = dquot_quota_off(sb, type);
1624         if (err)
1625                 goto out_put;
1626
1627         inode_lock(inode);
1628         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1629         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1630         inode_unlock(inode);
1631         mark_inode_dirty(inode);
1632 out_put:
1633         iput(inode);
1634         return err;
1635 out:
1636         return dquot_quota_off(sb, type);
1637 }
1638
1639 #endif
1640
1641 static struct file_system_type ext2_fs_type = {
1642         .owner          = THIS_MODULE,
1643         .name           = "ext2",
1644         .mount          = ext2_mount,
1645         .kill_sb        = kill_block_super,
1646         .fs_flags       = FS_REQUIRES_DEV,
1647 };
1648 MODULE_ALIAS_FS("ext2");
1649
1650 static int __init init_ext2_fs(void)
1651 {
1652         int err;
1653
1654         err = init_inodecache();
1655         if (err)
1656                 return err;
1657         err = register_filesystem(&ext2_fs_type);
1658         if (err)
1659                 goto out;
1660         return 0;
1661 out:
1662         destroy_inodecache();
1663         return err;
1664 }
1665
1666 static void __exit exit_ext2_fs(void)
1667 {
1668         unregister_filesystem(&ext2_fs_type);
1669         destroy_inodecache();
1670 }
1671
1672 MODULE_AUTHOR("Remy Card and others");
1673 MODULE_DESCRIPTION("Second Extended Filesystem");
1674 MODULE_LICENSE("GPL");
1675 module_init(init_ext2_fs)
1676 module_exit(exit_ext2_fs)