Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-drm-fsl-dcu.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 <asm/uaccess.h>
35 #include "ext2.h"
36 #include "xattr.h"
37 #include "acl.h"
38 #include "xip.h"
39
40 static void ext2_sync_super(struct super_block *sb,
41                             struct ext2_super_block *es, int wait);
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->s_flags & MS_RDONLY)) {
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 (test_opt(sb, ERRORS_RO)) {
77                 ext2_msg(sb, KERN_CRIT,
78                              "error: remounting filesystem read-only");
79                 sb->s_flags |= MS_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 static void ext2_put_super (struct super_block * sb)
128 {
129         int db_count;
130         int i;
131         struct ext2_sb_info *sbi = EXT2_SB(sb);
132
133         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
134
135         ext2_xattr_put_super(sb);
136         if (!(sb->s_flags & MS_RDONLY)) {
137                 struct ext2_super_block *es = sbi->s_es;
138
139                 spin_lock(&sbi->s_lock);
140                 es->s_state = cpu_to_le16(sbi->s_mount_state);
141                 spin_unlock(&sbi->s_lock);
142                 ext2_sync_super(sb, es, 1);
143         }
144         db_count = sbi->s_gdb_count;
145         for (i = 0; i < db_count; i++)
146                 if (sbi->s_group_desc[i])
147                         brelse (sbi->s_group_desc[i]);
148         kfree(sbi->s_group_desc);
149         kfree(sbi->s_debts);
150         percpu_counter_destroy(&sbi->s_freeblocks_counter);
151         percpu_counter_destroy(&sbi->s_freeinodes_counter);
152         percpu_counter_destroy(&sbi->s_dirs_counter);
153         brelse (sbi->s_sbh);
154         sb->s_fs_info = NULL;
155         kfree(sbi->s_blockgroup_lock);
156         kfree(sbi);
157 }
158
159 static struct kmem_cache * ext2_inode_cachep;
160
161 static struct inode *ext2_alloc_inode(struct super_block *sb)
162 {
163         struct ext2_inode_info *ei;
164         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
165         if (!ei)
166                 return NULL;
167         ei->i_block_alloc_info = NULL;
168         ei->vfs_inode.i_version = 1;
169         return &ei->vfs_inode;
170 }
171
172 static void ext2_i_callback(struct rcu_head *head)
173 {
174         struct inode *inode = container_of(head, struct inode, i_rcu);
175         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
176 }
177
178 static void ext2_destroy_inode(struct inode *inode)
179 {
180         call_rcu(&inode->i_rcu, ext2_i_callback);
181 }
182
183 static void init_once(void *foo)
184 {
185         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
186
187         rwlock_init(&ei->i_meta_lock);
188 #ifdef CONFIG_EXT2_FS_XATTR
189         init_rwsem(&ei->xattr_sem);
190 #endif
191         mutex_init(&ei->truncate_mutex);
192         inode_init_once(&ei->vfs_inode);
193 }
194
195 static int init_inodecache(void)
196 {
197         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
198                                              sizeof(struct ext2_inode_info),
199                                              0, (SLAB_RECLAIM_ACCOUNT|
200                                                 SLAB_MEM_SPREAD),
201                                              init_once);
202         if (ext2_inode_cachep == NULL)
203                 return -ENOMEM;
204         return 0;
205 }
206
207 static void destroy_inodecache(void)
208 {
209         kmem_cache_destroy(ext2_inode_cachep);
210 }
211
212 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
213 {
214         struct super_block *sb = root->d_sb;
215         struct ext2_sb_info *sbi = EXT2_SB(sb);
216         struct ext2_super_block *es = sbi->s_es;
217         unsigned long def_mount_opts;
218
219         spin_lock(&sbi->s_lock);
220         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
221
222         if (sbi->s_sb_block != 1)
223                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
224         if (test_opt(sb, MINIX_DF))
225                 seq_puts(seq, ",minixdf");
226         if (test_opt(sb, GRPID))
227                 seq_puts(seq, ",grpid");
228         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
229                 seq_puts(seq, ",nogrpid");
230         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
231             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
232                 seq_printf(seq, ",resuid=%u",
233                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
234         }
235         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
236             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
237                 seq_printf(seq, ",resgid=%u",
238                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
239         }
240         if (test_opt(sb, ERRORS_RO)) {
241                 int def_errors = le16_to_cpu(es->s_errors);
242
243                 if (def_errors == EXT2_ERRORS_PANIC ||
244                     def_errors == EXT2_ERRORS_CONTINUE) {
245                         seq_puts(seq, ",errors=remount-ro");
246                 }
247         }
248         if (test_opt(sb, ERRORS_CONT))
249                 seq_puts(seq, ",errors=continue");
250         if (test_opt(sb, ERRORS_PANIC))
251                 seq_puts(seq, ",errors=panic");
252         if (test_opt(sb, NO_UID32))
253                 seq_puts(seq, ",nouid32");
254         if (test_opt(sb, DEBUG))
255                 seq_puts(seq, ",debug");
256         if (test_opt(sb, OLDALLOC))
257                 seq_puts(seq, ",oldalloc");
258
259 #ifdef CONFIG_EXT2_FS_XATTR
260         if (test_opt(sb, XATTR_USER))
261                 seq_puts(seq, ",user_xattr");
262         if (!test_opt(sb, XATTR_USER) &&
263             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
264                 seq_puts(seq, ",nouser_xattr");
265         }
266 #endif
267
268 #ifdef CONFIG_EXT2_FS_POSIX_ACL
269         if (test_opt(sb, POSIX_ACL))
270                 seq_puts(seq, ",acl");
271         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
272                 seq_puts(seq, ",noacl");
273 #endif
274
275         if (test_opt(sb, NOBH))
276                 seq_puts(seq, ",nobh");
277
278 #if defined(CONFIG_QUOTA)
279         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
280                 seq_puts(seq, ",usrquota");
281
282         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
283                 seq_puts(seq, ",grpquota");
284 #endif
285
286 #if defined(CONFIG_EXT2_FS_XIP)
287         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
288                 seq_puts(seq, ",xip");
289 #endif
290
291         if (!test_opt(sb, RESERVATION))
292                 seq_puts(seq, ",noreservation");
293
294         spin_unlock(&sbi->s_lock);
295         return 0;
296 }
297
298 #ifdef CONFIG_QUOTA
299 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
300 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
301 #endif
302
303 static const struct super_operations ext2_sops = {
304         .alloc_inode    = ext2_alloc_inode,
305         .destroy_inode  = ext2_destroy_inode,
306         .write_inode    = ext2_write_inode,
307         .evict_inode    = ext2_evict_inode,
308         .put_super      = ext2_put_super,
309         .sync_fs        = ext2_sync_fs,
310         .freeze_fs      = ext2_freeze,
311         .unfreeze_fs    = ext2_unfreeze,
312         .statfs         = ext2_statfs,
313         .remount_fs     = ext2_remount,
314         .show_options   = ext2_show_options,
315 #ifdef CONFIG_QUOTA
316         .quota_read     = ext2_quota_read,
317         .quota_write    = ext2_quota_write,
318 #endif
319 };
320
321 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
322                 u64 ino, u32 generation)
323 {
324         struct inode *inode;
325
326         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
327                 return ERR_PTR(-ESTALE);
328         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
329                 return ERR_PTR(-ESTALE);
330
331         /*
332          * ext2_iget isn't quite right if the inode is currently unallocated!
333          * However ext2_iget currently does appropriate checks to handle stale
334          * inodes so everything is OK.
335          */
336         inode = ext2_iget(sb, ino);
337         if (IS_ERR(inode))
338                 return ERR_CAST(inode);
339         if (generation && inode->i_generation != generation) {
340                 /* we didn't find the right inode.. */
341                 iput(inode);
342                 return ERR_PTR(-ESTALE);
343         }
344         return inode;
345 }
346
347 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
348                 int fh_len, int fh_type)
349 {
350         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
351                                     ext2_nfs_get_inode);
352 }
353
354 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
355                 int fh_len, int fh_type)
356 {
357         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
358                                     ext2_nfs_get_inode);
359 }
360
361 static const struct export_operations ext2_export_ops = {
362         .fh_to_dentry = ext2_fh_to_dentry,
363         .fh_to_parent = ext2_fh_to_parent,
364         .get_parent = ext2_get_parent,
365 };
366
367 static unsigned long get_sb_block(void **data)
368 {
369         unsigned long   sb_block;
370         char            *options = (char *) *data;
371
372         if (!options || strncmp(options, "sb=", 3) != 0)
373                 return 1;       /* Default location */
374         options += 3;
375         sb_block = simple_strtoul(options, &options, 0);
376         if (*options && *options != ',') {
377                 printk("EXT2-fs: Invalid sb specification: %s\n",
378                        (char *) *data);
379                 return 1;
380         }
381         if (*options == ',')
382                 options++;
383         *data = (void *) options;
384         return sb_block;
385 }
386
387 enum {
388         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
389         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
390         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
391         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
392         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
393         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
394 };
395
396 static const match_table_t tokens = {
397         {Opt_bsd_df, "bsddf"},
398         {Opt_minix_df, "minixdf"},
399         {Opt_grpid, "grpid"},
400         {Opt_grpid, "bsdgroups"},
401         {Opt_nogrpid, "nogrpid"},
402         {Opt_nogrpid, "sysvgroups"},
403         {Opt_resgid, "resgid=%u"},
404         {Opt_resuid, "resuid=%u"},
405         {Opt_sb, "sb=%u"},
406         {Opt_err_cont, "errors=continue"},
407         {Opt_err_panic, "errors=panic"},
408         {Opt_err_ro, "errors=remount-ro"},
409         {Opt_nouid32, "nouid32"},
410         {Opt_nocheck, "check=none"},
411         {Opt_nocheck, "nocheck"},
412         {Opt_debug, "debug"},
413         {Opt_oldalloc, "oldalloc"},
414         {Opt_orlov, "orlov"},
415         {Opt_nobh, "nobh"},
416         {Opt_user_xattr, "user_xattr"},
417         {Opt_nouser_xattr, "nouser_xattr"},
418         {Opt_acl, "acl"},
419         {Opt_noacl, "noacl"},
420         {Opt_xip, "xip"},
421         {Opt_grpquota, "grpquota"},
422         {Opt_ignore, "noquota"},
423         {Opt_quota, "quota"},
424         {Opt_usrquota, "usrquota"},
425         {Opt_reservation, "reservation"},
426         {Opt_noreservation, "noreservation"},
427         {Opt_err, NULL}
428 };
429
430 static int parse_options(char *options, struct super_block *sb)
431 {
432         char *p;
433         struct ext2_sb_info *sbi = EXT2_SB(sb);
434         substring_t args[MAX_OPT_ARGS];
435         int option;
436         kuid_t uid;
437         kgid_t gid;
438
439         if (!options)
440                 return 1;
441
442         while ((p = strsep (&options, ",")) != NULL) {
443                 int token;
444                 if (!*p)
445                         continue;
446
447                 token = match_token(p, tokens, args);
448                 switch (token) {
449                 case Opt_bsd_df:
450                         clear_opt (sbi->s_mount_opt, MINIX_DF);
451                         break;
452                 case Opt_minix_df:
453                         set_opt (sbi->s_mount_opt, MINIX_DF);
454                         break;
455                 case Opt_grpid:
456                         set_opt (sbi->s_mount_opt, GRPID);
457                         break;
458                 case Opt_nogrpid:
459                         clear_opt (sbi->s_mount_opt, GRPID);
460                         break;
461                 case Opt_resuid:
462                         if (match_int(&args[0], &option))
463                                 return 0;
464                         uid = make_kuid(current_user_ns(), option);
465                         if (!uid_valid(uid)) {
466                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
467                                 return -1;
468
469                         }
470                         sbi->s_resuid = uid;
471                         break;
472                 case Opt_resgid:
473                         if (match_int(&args[0], &option))
474                                 return 0;
475                         gid = make_kgid(current_user_ns(), option);
476                         if (!gid_valid(gid)) {
477                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
478                                 return -1;
479                         }
480                         sbi->s_resgid = gid;
481                         break;
482                 case Opt_sb:
483                         /* handled by get_sb_block() instead of here */
484                         /* *sb_block = match_int(&args[0]); */
485                         break;
486                 case Opt_err_panic:
487                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
488                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
489                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
490                         break;
491                 case Opt_err_ro:
492                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
493                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
494                         set_opt (sbi->s_mount_opt, ERRORS_RO);
495                         break;
496                 case Opt_err_cont:
497                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
498                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
499                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
500                         break;
501                 case Opt_nouid32:
502                         set_opt (sbi->s_mount_opt, NO_UID32);
503                         break;
504                 case Opt_nocheck:
505                         clear_opt (sbi->s_mount_opt, CHECK);
506                         break;
507                 case Opt_debug:
508                         set_opt (sbi->s_mount_opt, DEBUG);
509                         break;
510                 case Opt_oldalloc:
511                         set_opt (sbi->s_mount_opt, OLDALLOC);
512                         break;
513                 case Opt_orlov:
514                         clear_opt (sbi->s_mount_opt, OLDALLOC);
515                         break;
516                 case Opt_nobh:
517                         set_opt (sbi->s_mount_opt, NOBH);
518                         break;
519 #ifdef CONFIG_EXT2_FS_XATTR
520                 case Opt_user_xattr:
521                         set_opt (sbi->s_mount_opt, XATTR_USER);
522                         break;
523                 case Opt_nouser_xattr:
524                         clear_opt (sbi->s_mount_opt, XATTR_USER);
525                         break;
526 #else
527                 case Opt_user_xattr:
528                 case Opt_nouser_xattr:
529                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
530                                 "not supported");
531                         break;
532 #endif
533 #ifdef CONFIG_EXT2_FS_POSIX_ACL
534                 case Opt_acl:
535                         set_opt(sbi->s_mount_opt, POSIX_ACL);
536                         break;
537                 case Opt_noacl:
538                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
539                         break;
540 #else
541                 case Opt_acl:
542                 case Opt_noacl:
543                         ext2_msg(sb, KERN_INFO,
544                                 "(no)acl options not supported");
545                         break;
546 #endif
547                 case Opt_xip:
548 #ifdef CONFIG_EXT2_FS_XIP
549                         set_opt (sbi->s_mount_opt, XIP);
550 #else
551                         ext2_msg(sb, KERN_INFO, "xip option not supported");
552 #endif
553                         break;
554
555 #if defined(CONFIG_QUOTA)
556                 case Opt_quota:
557                 case Opt_usrquota:
558                         set_opt(sbi->s_mount_opt, USRQUOTA);
559                         break;
560
561                 case Opt_grpquota:
562                         set_opt(sbi->s_mount_opt, GRPQUOTA);
563                         break;
564 #else
565                 case Opt_quota:
566                 case Opt_usrquota:
567                 case Opt_grpquota:
568                         ext2_msg(sb, KERN_INFO,
569                                 "quota operations not supported");
570                         break;
571 #endif
572
573                 case Opt_reservation:
574                         set_opt(sbi->s_mount_opt, RESERVATION);
575                         ext2_msg(sb, KERN_INFO, "reservations ON");
576                         break;
577                 case Opt_noreservation:
578                         clear_opt(sbi->s_mount_opt, RESERVATION);
579                         ext2_msg(sb, KERN_INFO, "reservations OFF");
580                         break;
581                 case Opt_ignore:
582                         break;
583                 default:
584                         return 0;
585                 }
586         }
587         return 1;
588 }
589
590 static int ext2_setup_super (struct super_block * sb,
591                               struct ext2_super_block * es,
592                               int read_only)
593 {
594         int res = 0;
595         struct ext2_sb_info *sbi = EXT2_SB(sb);
596
597         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
598                 ext2_msg(sb, KERN_ERR,
599                         "error: revision level too high, "
600                         "forcing read-only mode");
601                 res = MS_RDONLY;
602         }
603         if (read_only)
604                 return res;
605         if (!(sbi->s_mount_state & EXT2_VALID_FS))
606                 ext2_msg(sb, KERN_WARNING,
607                         "warning: mounting unchecked fs, "
608                         "running e2fsck is recommended");
609         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
610                 ext2_msg(sb, KERN_WARNING,
611                         "warning: mounting fs with errors, "
612                         "running e2fsck is recommended");
613         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
614                  le16_to_cpu(es->s_mnt_count) >=
615                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
616                 ext2_msg(sb, KERN_WARNING,
617                         "warning: maximal mount count reached, "
618                         "running e2fsck is recommended");
619         else if (le32_to_cpu(es->s_checkinterval) &&
620                 (le32_to_cpu(es->s_lastcheck) +
621                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
622                 ext2_msg(sb, KERN_WARNING,
623                         "warning: checktime reached, "
624                         "running e2fsck is recommended");
625         if (!le16_to_cpu(es->s_max_mnt_count))
626                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
627         le16_add_cpu(&es->s_mnt_count, 1);
628         if (test_opt (sb, DEBUG))
629                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
630                         "bpg=%lu, ipg=%lu, mo=%04lx]",
631                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
632                         sbi->s_frag_size,
633                         sbi->s_groups_count,
634                         EXT2_BLOCKS_PER_GROUP(sb),
635                         EXT2_INODES_PER_GROUP(sb),
636                         sbi->s_mount_opt);
637         return res;
638 }
639
640 static int ext2_check_descriptors(struct super_block *sb)
641 {
642         int i;
643         struct ext2_sb_info *sbi = EXT2_SB(sb);
644
645         ext2_debug ("Checking group descriptors");
646
647         for (i = 0; i < sbi->s_groups_count; i++) {
648                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
649                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
650                 ext2_fsblk_t last_block;
651
652                 if (i == sbi->s_groups_count - 1)
653                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
654                 else
655                         last_block = first_block +
656                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
657
658                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
659                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
660                 {
661                         ext2_error (sb, "ext2_check_descriptors",
662                                     "Block bitmap for group %d"
663                                     " not in group (block %lu)!",
664                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
665                         return 0;
666                 }
667                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
668                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
669                 {
670                         ext2_error (sb, "ext2_check_descriptors",
671                                     "Inode bitmap for group %d"
672                                     " not in group (block %lu)!",
673                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
674                         return 0;
675                 }
676                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
677                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
678                     last_block)
679                 {
680                         ext2_error (sb, "ext2_check_descriptors",
681                                     "Inode table for group %d"
682                                     " not in group (block %lu)!",
683                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
684                         return 0;
685                 }
686         }
687         return 1;
688 }
689
690 /*
691  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
692  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
693  * We need to be 1 filesystem block less than the 2^32 sector limit.
694  */
695 static loff_t ext2_max_size(int bits)
696 {
697         loff_t res = EXT2_NDIR_BLOCKS;
698         int meta_blocks;
699         loff_t upper_limit;
700
701         /* This is calculated to be the largest file size for a
702          * dense, file such that the total number of
703          * sectors in the file, including data and all indirect blocks,
704          * does not exceed 2^32 -1
705          * __u32 i_blocks representing the total number of
706          * 512 bytes blocks of the file
707          */
708         upper_limit = (1LL << 32) - 1;
709
710         /* total blocks in file system block size */
711         upper_limit >>= (bits - 9);
712
713
714         /* indirect blocks */
715         meta_blocks = 1;
716         /* double indirect blocks */
717         meta_blocks += 1 + (1LL << (bits-2));
718         /* tripple indirect blocks */
719         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
720
721         upper_limit -= meta_blocks;
722         upper_limit <<= bits;
723
724         res += 1LL << (bits-2);
725         res += 1LL << (2*(bits-2));
726         res += 1LL << (3*(bits-2));
727         res <<= bits;
728         if (res > upper_limit)
729                 res = upper_limit;
730
731         if (res > MAX_LFS_FILESIZE)
732                 res = MAX_LFS_FILESIZE;
733
734         return res;
735 }
736
737 static unsigned long descriptor_loc(struct super_block *sb,
738                                     unsigned long logic_sb_block,
739                                     int nr)
740 {
741         struct ext2_sb_info *sbi = EXT2_SB(sb);
742         unsigned long bg, first_meta_bg;
743         int has_super = 0;
744         
745         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
746
747         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
748             nr < first_meta_bg)
749                 return (logic_sb_block + nr + 1);
750         bg = sbi->s_desc_per_block * nr;
751         if (ext2_bg_has_super(sb, bg))
752                 has_super = 1;
753
754         return ext2_group_first_block_no(sb, bg) + has_super;
755 }
756
757 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
758 {
759         struct buffer_head * bh;
760         struct ext2_sb_info * sbi;
761         struct ext2_super_block * es;
762         struct inode *root;
763         unsigned long block;
764         unsigned long sb_block = get_sb_block(&data);
765         unsigned long logic_sb_block;
766         unsigned long offset = 0;
767         unsigned long def_mount_opts;
768         long ret = -EINVAL;
769         int blocksize = BLOCK_SIZE;
770         int db_count;
771         int i, j;
772         __le32 features;
773         int err;
774
775         err = -ENOMEM;
776         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
777         if (!sbi)
778                 goto failed;
779
780         sbi->s_blockgroup_lock =
781                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
782         if (!sbi->s_blockgroup_lock) {
783                 kfree(sbi);
784                 goto failed;
785         }
786         sb->s_fs_info = sbi;
787         sbi->s_sb_block = sb_block;
788
789         spin_lock_init(&sbi->s_lock);
790
791         /*
792          * See what the current blocksize for the device is, and
793          * use that as the blocksize.  Otherwise (or if the blocksize
794          * is smaller than the default) use the default.
795          * This is important for devices that have a hardware
796          * sectorsize that is larger than the default.
797          */
798         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
799         if (!blocksize) {
800                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
801                 goto failed_sbi;
802         }
803
804         /*
805          * If the superblock doesn't start on a hardware sector boundary,
806          * calculate the offset.  
807          */
808         if (blocksize != BLOCK_SIZE) {
809                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
810                 offset = (sb_block*BLOCK_SIZE) % blocksize;
811         } else {
812                 logic_sb_block = sb_block;
813         }
814
815         if (!(bh = sb_bread(sb, logic_sb_block))) {
816                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
817                 goto failed_sbi;
818         }
819         /*
820          * Note: s_es must be initialized as soon as possible because
821          *       some ext2 macro-instructions depend on its value
822          */
823         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
824         sbi->s_es = es;
825         sb->s_magic = le16_to_cpu(es->s_magic);
826
827         if (sb->s_magic != EXT2_SUPER_MAGIC)
828                 goto cantfind_ext2;
829
830         /* Set defaults before we parse the mount options */
831         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
832         if (def_mount_opts & EXT2_DEFM_DEBUG)
833                 set_opt(sbi->s_mount_opt, DEBUG);
834         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
835                 set_opt(sbi->s_mount_opt, GRPID);
836         if (def_mount_opts & EXT2_DEFM_UID16)
837                 set_opt(sbi->s_mount_opt, NO_UID32);
838 #ifdef CONFIG_EXT2_FS_XATTR
839         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
840                 set_opt(sbi->s_mount_opt, XATTR_USER);
841 #endif
842 #ifdef CONFIG_EXT2_FS_POSIX_ACL
843         if (def_mount_opts & EXT2_DEFM_ACL)
844                 set_opt(sbi->s_mount_opt, POSIX_ACL);
845 #endif
846         
847         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
848                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
849         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
850                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
851         else
852                 set_opt(sbi->s_mount_opt, ERRORS_RO);
853
854         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
855         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
856         
857         set_opt(sbi->s_mount_opt, RESERVATION);
858
859         if (!parse_options((char *) data, sb))
860                 goto failed_mount;
861
862         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
863                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
864                  MS_POSIXACL : 0);
865
866         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
867                                     EXT2_MOUNT_XIP if not */
868
869         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
870             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
871              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
872              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
873                 ext2_msg(sb, KERN_WARNING,
874                         "warning: feature flags set on rev 0 fs, "
875                         "running e2fsck is recommended");
876         /*
877          * Check feature flags regardless of the revision level, since we
878          * previously didn't change the revision level when setting the flags,
879          * so there is a chance incompat flags are set on a rev 0 filesystem.
880          */
881         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
882         if (features) {
883                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
884                        "unsupported optional features (%x)",
885                         le32_to_cpu(features));
886                 goto failed_mount;
887         }
888         if (!(sb->s_flags & MS_RDONLY) &&
889             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
890                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
891                        "unsupported optional features (%x)",
892                        le32_to_cpu(features));
893                 goto failed_mount;
894         }
895
896         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
897
898         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
899                 if (!silent)
900                         ext2_msg(sb, KERN_ERR,
901                                 "error: unsupported blocksize for xip");
902                 goto failed_mount;
903         }
904
905         /* If the blocksize doesn't match, re-read the thing.. */
906         if (sb->s_blocksize != blocksize) {
907                 brelse(bh);
908
909                 if (!sb_set_blocksize(sb, blocksize)) {
910                         ext2_msg(sb, KERN_ERR,
911                                 "error: bad blocksize %d", blocksize);
912                         goto failed_sbi;
913                 }
914
915                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
916                 offset = (sb_block*BLOCK_SIZE) % blocksize;
917                 bh = sb_bread(sb, logic_sb_block);
918                 if(!bh) {
919                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
920                                 "superblock on 2nd try");
921                         goto failed_sbi;
922                 }
923                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
924                 sbi->s_es = es;
925                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
926                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
927                         goto failed_mount;
928                 }
929         }
930
931         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
932         sb->s_max_links = EXT2_LINK_MAX;
933
934         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
935                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
936                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
937         } else {
938                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
939                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
940                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
941                     !is_power_of_2(sbi->s_inode_size) ||
942                     (sbi->s_inode_size > blocksize)) {
943                         ext2_msg(sb, KERN_ERR,
944                                 "error: unsupported inode size: %d",
945                                 sbi->s_inode_size);
946                         goto failed_mount;
947                 }
948         }
949
950         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
951                                    le32_to_cpu(es->s_log_frag_size);
952         if (sbi->s_frag_size == 0)
953                 goto cantfind_ext2;
954         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
955
956         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
957         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
958         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
959
960         if (EXT2_INODE_SIZE(sb) == 0)
961                 goto cantfind_ext2;
962         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
963         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
964                 goto cantfind_ext2;
965         sbi->s_itb_per_group = sbi->s_inodes_per_group /
966                                         sbi->s_inodes_per_block;
967         sbi->s_desc_per_block = sb->s_blocksize /
968                                         sizeof (struct ext2_group_desc);
969         sbi->s_sbh = bh;
970         sbi->s_mount_state = le16_to_cpu(es->s_state);
971         sbi->s_addr_per_block_bits =
972                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
973         sbi->s_desc_per_block_bits =
974                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
975
976         if (sb->s_magic != EXT2_SUPER_MAGIC)
977                 goto cantfind_ext2;
978
979         if (sb->s_blocksize != bh->b_size) {
980                 if (!silent)
981                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
982                 goto failed_mount;
983         }
984
985         if (sb->s_blocksize != sbi->s_frag_size) {
986                 ext2_msg(sb, KERN_ERR,
987                         "error: fragsize %lu != blocksize %lu"
988                         "(not supported yet)",
989                         sbi->s_frag_size, sb->s_blocksize);
990                 goto failed_mount;
991         }
992
993         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
994                 ext2_msg(sb, KERN_ERR,
995                         "error: #blocks per group too big: %lu",
996                         sbi->s_blocks_per_group);
997                 goto failed_mount;
998         }
999         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1000                 ext2_msg(sb, KERN_ERR,
1001                         "error: #fragments per group too big: %lu",
1002                         sbi->s_frags_per_group);
1003                 goto failed_mount;
1004         }
1005         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1006                 ext2_msg(sb, KERN_ERR,
1007                         "error: #inodes per group too big: %lu",
1008                         sbi->s_inodes_per_group);
1009                 goto failed_mount;
1010         }
1011
1012         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1013                 goto cantfind_ext2;
1014         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1015                                 le32_to_cpu(es->s_first_data_block) - 1)
1016                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1017         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1018                    EXT2_DESC_PER_BLOCK(sb);
1019         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1020         if (sbi->s_group_desc == NULL) {
1021                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1022                 goto failed_mount;
1023         }
1024         bgl_lock_init(sbi->s_blockgroup_lock);
1025         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1026         if (!sbi->s_debts) {
1027                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1028                 goto failed_mount_group_desc;
1029         }
1030         for (i = 0; i < db_count; i++) {
1031                 block = descriptor_loc(sb, logic_sb_block, i);
1032                 sbi->s_group_desc[i] = sb_bread(sb, block);
1033                 if (!sbi->s_group_desc[i]) {
1034                         for (j = 0; j < i; j++)
1035                                 brelse (sbi->s_group_desc[j]);
1036                         ext2_msg(sb, KERN_ERR,
1037                                 "error: unable to read group descriptors");
1038                         goto failed_mount_group_desc;
1039                 }
1040         }
1041         if (!ext2_check_descriptors (sb)) {
1042                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1043                 goto failed_mount2;
1044         }
1045         sbi->s_gdb_count = db_count;
1046         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1047         spin_lock_init(&sbi->s_next_gen_lock);
1048
1049         /* per fileystem reservation list head & lock */
1050         spin_lock_init(&sbi->s_rsv_window_lock);
1051         sbi->s_rsv_window_root = RB_ROOT;
1052         /*
1053          * Add a single, static dummy reservation to the start of the
1054          * reservation window list --- it gives us a placeholder for
1055          * append-at-start-of-list which makes the allocation logic
1056          * _much_ simpler.
1057          */
1058         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1059         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1060         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1061         sbi->s_rsv_window_head.rsv_goal_size = 0;
1062         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1063
1064         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1065                                 ext2_count_free_blocks(sb));
1066         if (!err) {
1067                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1068                                 ext2_count_free_inodes(sb));
1069         }
1070         if (!err) {
1071                 err = percpu_counter_init(&sbi->s_dirs_counter,
1072                                 ext2_count_dirs(sb));
1073         }
1074         if (err) {
1075                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1076                 goto failed_mount3;
1077         }
1078         /*
1079          * set up enough so that it can read an inode
1080          */
1081         sb->s_op = &ext2_sops;
1082         sb->s_export_op = &ext2_export_ops;
1083         sb->s_xattr = ext2_xattr_handlers;
1084
1085 #ifdef CONFIG_QUOTA
1086         sb->dq_op = &dquot_operations;
1087         sb->s_qcop = &dquot_quotactl_ops;
1088 #endif
1089
1090         root = ext2_iget(sb, EXT2_ROOT_INO);
1091         if (IS_ERR(root)) {
1092                 ret = PTR_ERR(root);
1093                 goto failed_mount3;
1094         }
1095         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1096                 iput(root);
1097                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1098                 goto failed_mount3;
1099         }
1100
1101         sb->s_root = d_make_root(root);
1102         if (!sb->s_root) {
1103                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1104                 ret = -ENOMEM;
1105                 goto failed_mount3;
1106         }
1107         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1108                 ext2_msg(sb, KERN_WARNING,
1109                         "warning: mounting ext3 filesystem as ext2");
1110         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1111                 sb->s_flags |= MS_RDONLY;
1112         ext2_write_super(sb);
1113         return 0;
1114
1115 cantfind_ext2:
1116         if (!silent)
1117                 ext2_msg(sb, KERN_ERR,
1118                         "error: can't find an ext2 filesystem on dev %s.",
1119                         sb->s_id);
1120         goto failed_mount;
1121 failed_mount3:
1122         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1123         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1124         percpu_counter_destroy(&sbi->s_dirs_counter);
1125 failed_mount2:
1126         for (i = 0; i < db_count; i++)
1127                 brelse(sbi->s_group_desc[i]);
1128 failed_mount_group_desc:
1129         kfree(sbi->s_group_desc);
1130         kfree(sbi->s_debts);
1131 failed_mount:
1132         brelse(bh);
1133 failed_sbi:
1134         sb->s_fs_info = NULL;
1135         kfree(sbi->s_blockgroup_lock);
1136         kfree(sbi);
1137 failed:
1138         return ret;
1139 }
1140
1141 static void ext2_clear_super_error(struct super_block *sb)
1142 {
1143         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1144
1145         if (buffer_write_io_error(sbh)) {
1146                 /*
1147                  * Oh, dear.  A previous attempt to write the
1148                  * superblock failed.  This could happen because the
1149                  * USB device was yanked out.  Or it could happen to
1150                  * be a transient write error and maybe the block will
1151                  * be remapped.  Nothing we can do but to retry the
1152                  * write and hope for the best.
1153                  */
1154                 ext2_msg(sb, KERN_ERR,
1155                        "previous I/O error to superblock detected\n");
1156                 clear_buffer_write_io_error(sbh);
1157                 set_buffer_uptodate(sbh);
1158         }
1159 }
1160
1161 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1162                             int wait)
1163 {
1164         ext2_clear_super_error(sb);
1165         spin_lock(&EXT2_SB(sb)->s_lock);
1166         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1167         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1168         es->s_wtime = cpu_to_le32(get_seconds());
1169         /* unlock before we do IO */
1170         spin_unlock(&EXT2_SB(sb)->s_lock);
1171         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1172         if (wait)
1173                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1174 }
1175
1176 /*
1177  * In the second extended file system, it is not necessary to
1178  * write the super block since we use a mapping of the
1179  * disk super block in a buffer.
1180  *
1181  * However, this function is still used to set the fs valid
1182  * flags to 0.  We need to set this flag to 0 since the fs
1183  * may have been checked while mounted and e2fsck may have
1184  * set s_state to EXT2_VALID_FS after some corrections.
1185  */
1186 static int ext2_sync_fs(struct super_block *sb, int wait)
1187 {
1188         struct ext2_sb_info *sbi = EXT2_SB(sb);
1189         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1190
1191         /*
1192          * Write quota structures to quota file, sync_blockdev() will write
1193          * them to disk later
1194          */
1195         dquot_writeback_dquots(sb, -1);
1196
1197         spin_lock(&sbi->s_lock);
1198         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1199                 ext2_debug("setting valid to 0\n");
1200                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1201         }
1202         spin_unlock(&sbi->s_lock);
1203         ext2_sync_super(sb, es, wait);
1204         return 0;
1205 }
1206
1207 static int ext2_freeze(struct super_block *sb)
1208 {
1209         struct ext2_sb_info *sbi = EXT2_SB(sb);
1210
1211         /*
1212          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1213          * because we have unattached inodes and thus filesystem is not fully
1214          * consistent.
1215          */
1216         if (atomic_long_read(&sb->s_remove_count)) {
1217                 ext2_sync_fs(sb, 1);
1218                 return 0;
1219         }
1220         /* Set EXT2_FS_VALID flag */
1221         spin_lock(&sbi->s_lock);
1222         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1223         spin_unlock(&sbi->s_lock);
1224         ext2_sync_super(sb, sbi->s_es, 1);
1225
1226         return 0;
1227 }
1228
1229 static int ext2_unfreeze(struct super_block *sb)
1230 {
1231         /* Just write sb to clear EXT2_VALID_FS flag */
1232         ext2_write_super(sb);
1233
1234         return 0;
1235 }
1236
1237 void ext2_write_super(struct super_block *sb)
1238 {
1239         if (!(sb->s_flags & MS_RDONLY))
1240                 ext2_sync_fs(sb, 1);
1241 }
1242
1243 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1244 {
1245         struct ext2_sb_info * sbi = EXT2_SB(sb);
1246         struct ext2_super_block * es;
1247         unsigned long old_mount_opt = sbi->s_mount_opt;
1248         struct ext2_mount_options old_opts;
1249         unsigned long old_sb_flags;
1250         int err;
1251
1252         spin_lock(&sbi->s_lock);
1253
1254         /* Store the old options */
1255         old_sb_flags = sb->s_flags;
1256         old_opts.s_mount_opt = sbi->s_mount_opt;
1257         old_opts.s_resuid = sbi->s_resuid;
1258         old_opts.s_resgid = sbi->s_resgid;
1259
1260         /*
1261          * Allow the "check" option to be passed as a remount option.
1262          */
1263         if (!parse_options(data, sb)) {
1264                 err = -EINVAL;
1265                 goto restore_opts;
1266         }
1267
1268         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1269                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1270
1271         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1272                                     EXT2_MOUNT_XIP if not */
1273
1274         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1275                 ext2_msg(sb, KERN_WARNING,
1276                         "warning: unsupported blocksize for xip");
1277                 err = -EINVAL;
1278                 goto restore_opts;
1279         }
1280
1281         es = sbi->s_es;
1282         if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1283                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1284                          "xip flag with busy inodes while remounting");
1285                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1286                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1287         }
1288         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1289                 spin_unlock(&sbi->s_lock);
1290                 return 0;
1291         }
1292         if (*flags & MS_RDONLY) {
1293                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1294                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1295                         spin_unlock(&sbi->s_lock);
1296                         return 0;
1297                 }
1298
1299                 /*
1300                  * OK, we are remounting a valid rw partition rdonly, so set
1301                  * the rdonly flag and then mark the partition as valid again.
1302                  */
1303                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1304                 es->s_mtime = cpu_to_le32(get_seconds());
1305                 spin_unlock(&sbi->s_lock);
1306
1307                 err = dquot_suspend(sb, -1);
1308                 if (err < 0) {
1309                         spin_lock(&sbi->s_lock);
1310                         goto restore_opts;
1311                 }
1312
1313                 ext2_sync_super(sb, es, 1);
1314         } else {
1315                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1316                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1317                 if (ret) {
1318                         ext2_msg(sb, KERN_WARNING,
1319                                 "warning: couldn't remount RDWR because of "
1320                                 "unsupported optional features (%x).",
1321                                 le32_to_cpu(ret));
1322                         err = -EROFS;
1323                         goto restore_opts;
1324                 }
1325                 /*
1326                  * Mounting a RDONLY partition read-write, so reread and
1327                  * store the current valid flag.  (It may have been changed
1328                  * by e2fsck since we originally mounted the partition.)
1329                  */
1330                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1331                 if (!ext2_setup_super (sb, es, 0))
1332                         sb->s_flags &= ~MS_RDONLY;
1333                 spin_unlock(&sbi->s_lock);
1334
1335                 ext2_write_super(sb);
1336
1337                 dquot_resume(sb, -1);
1338         }
1339
1340         return 0;
1341 restore_opts:
1342         sbi->s_mount_opt = old_opts.s_mount_opt;
1343         sbi->s_resuid = old_opts.s_resuid;
1344         sbi->s_resgid = old_opts.s_resgid;
1345         sb->s_flags = old_sb_flags;
1346         spin_unlock(&sbi->s_lock);
1347         return err;
1348 }
1349
1350 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1351 {
1352         struct super_block *sb = dentry->d_sb;
1353         struct ext2_sb_info *sbi = EXT2_SB(sb);
1354         struct ext2_super_block *es = sbi->s_es;
1355         u64 fsid;
1356
1357         spin_lock(&sbi->s_lock);
1358
1359         if (test_opt (sb, MINIX_DF))
1360                 sbi->s_overhead_last = 0;
1361         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1362                 unsigned long i, overhead = 0;
1363                 smp_rmb();
1364
1365                 /*
1366                  * Compute the overhead (FS structures). This is constant
1367                  * for a given filesystem unless the number of block groups
1368                  * changes so we cache the previous value until it does.
1369                  */
1370
1371                 /*
1372                  * All of the blocks before first_data_block are
1373                  * overhead
1374                  */
1375                 overhead = le32_to_cpu(es->s_first_data_block);
1376
1377                 /*
1378                  * Add the overhead attributed to the superblock and
1379                  * block group descriptors.  If the sparse superblocks
1380                  * feature is turned on, then not all groups have this.
1381                  */
1382                 for (i = 0; i < sbi->s_groups_count; i++)
1383                         overhead += ext2_bg_has_super(sb, i) +
1384                                 ext2_bg_num_gdb(sb, i);
1385
1386                 /*
1387                  * Every block group has an inode bitmap, a block
1388                  * bitmap, and an inode table.
1389                  */
1390                 overhead += (sbi->s_groups_count *
1391                              (2 + sbi->s_itb_per_group));
1392                 sbi->s_overhead_last = overhead;
1393                 smp_wmb();
1394                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1395         }
1396
1397         buf->f_type = EXT2_SUPER_MAGIC;
1398         buf->f_bsize = sb->s_blocksize;
1399         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1400         buf->f_bfree = ext2_count_free_blocks(sb);
1401         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1402         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1403         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1404                 buf->f_bavail = 0;
1405         buf->f_files = le32_to_cpu(es->s_inodes_count);
1406         buf->f_ffree = ext2_count_free_inodes(sb);
1407         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1408         buf->f_namelen = EXT2_NAME_LEN;
1409         fsid = le64_to_cpup((void *)es->s_uuid) ^
1410                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1411         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1412         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1413         spin_unlock(&sbi->s_lock);
1414         return 0;
1415 }
1416
1417 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1418         int flags, const char *dev_name, void *data)
1419 {
1420         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1421 }
1422
1423 #ifdef CONFIG_QUOTA
1424
1425 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1426  * acquiring the locks... As quota files are never truncated and quota code
1427  * itself serializes the operations (and no one else should touch the files)
1428  * we don't have to be afraid of races */
1429 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1430                                size_t len, loff_t off)
1431 {
1432         struct inode *inode = sb_dqopt(sb)->files[type];
1433         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1434         int err = 0;
1435         int offset = off & (sb->s_blocksize - 1);
1436         int tocopy;
1437         size_t toread;
1438         struct buffer_head tmp_bh;
1439         struct buffer_head *bh;
1440         loff_t i_size = i_size_read(inode);
1441
1442         if (off > i_size)
1443                 return 0;
1444         if (off+len > i_size)
1445                 len = i_size-off;
1446         toread = len;
1447         while (toread > 0) {
1448                 tocopy = sb->s_blocksize - offset < toread ?
1449                                 sb->s_blocksize - offset : toread;
1450
1451                 tmp_bh.b_state = 0;
1452                 tmp_bh.b_size = sb->s_blocksize;
1453                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1454                 if (err < 0)
1455                         return err;
1456                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1457                         memset(data, 0, tocopy);
1458                 else {
1459                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1460                         if (!bh)
1461                                 return -EIO;
1462                         memcpy(data, bh->b_data+offset, tocopy);
1463                         brelse(bh);
1464                 }
1465                 offset = 0;
1466                 toread -= tocopy;
1467                 data += tocopy;
1468                 blk++;
1469         }
1470         return len;
1471 }
1472
1473 /* Write to quotafile */
1474 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1475                                 const char *data, size_t len, loff_t off)
1476 {
1477         struct inode *inode = sb_dqopt(sb)->files[type];
1478         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1479         int err = 0;
1480         int offset = off & (sb->s_blocksize - 1);
1481         int tocopy;
1482         size_t towrite = len;
1483         struct buffer_head tmp_bh;
1484         struct buffer_head *bh;
1485
1486         while (towrite > 0) {
1487                 tocopy = sb->s_blocksize - offset < towrite ?
1488                                 sb->s_blocksize - offset : towrite;
1489
1490                 tmp_bh.b_state = 0;
1491                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1492                 if (err < 0)
1493                         goto out;
1494                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1495                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1496                 else
1497                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1498                 if (!bh) {
1499                         err = -EIO;
1500                         goto out;
1501                 }
1502                 lock_buffer(bh);
1503                 memcpy(bh->b_data+offset, data, tocopy);
1504                 flush_dcache_page(bh->b_page);
1505                 set_buffer_uptodate(bh);
1506                 mark_buffer_dirty(bh);
1507                 unlock_buffer(bh);
1508                 brelse(bh);
1509                 offset = 0;
1510                 towrite -= tocopy;
1511                 data += tocopy;
1512                 blk++;
1513         }
1514 out:
1515         if (len == towrite)
1516                 return err;
1517         if (inode->i_size < off+len-towrite)
1518                 i_size_write(inode, off+len-towrite);
1519         inode->i_version++;
1520         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1521         mark_inode_dirty(inode);
1522         return len - towrite;
1523 }
1524
1525 #endif
1526
1527 static struct file_system_type ext2_fs_type = {
1528         .owner          = THIS_MODULE,
1529         .name           = "ext2",
1530         .mount          = ext2_mount,
1531         .kill_sb        = kill_block_super,
1532         .fs_flags       = FS_REQUIRES_DEV,
1533 };
1534
1535 static int __init init_ext2_fs(void)
1536 {
1537         int err = init_ext2_xattr();
1538         if (err)
1539                 return err;
1540         err = init_inodecache();
1541         if (err)
1542                 goto out1;
1543         err = register_filesystem(&ext2_fs_type);
1544         if (err)
1545                 goto out;
1546         return 0;
1547 out:
1548         destroy_inodecache();
1549 out1:
1550         exit_ext2_xattr();
1551         return err;
1552 }
1553
1554 static void __exit exit_ext2_fs(void)
1555 {
1556         unregister_filesystem(&ext2_fs_type);
1557         destroy_inodecache();
1558         exit_ext2_xattr();
1559 }
1560
1561 MODULE_AUTHOR("Remy Card and others");
1562 MODULE_DESCRIPTION("Second Extended Filesystem");
1563 MODULE_LICENSE("GPL");
1564 module_init(init_ext2_fs)
1565 module_exit(exit_ext2_fs)