fs/ext2/super.c: Use printf extension %pV
[linux-2.6.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
46 void ext2_error(struct super_block *sb, const char *function,
47                 const char *fmt, ...)
48 {
49         struct va_format vaf;
50         va_list args;
51         struct ext2_sb_info *sbi = EXT2_SB(sb);
52         struct ext2_super_block *es = sbi->s_es;
53
54         if (!(sb->s_flags & MS_RDONLY)) {
55                 spin_lock(&sbi->s_lock);
56                 sbi->s_mount_state |= EXT2_ERROR_FS;
57                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
58                 spin_unlock(&sbi->s_lock);
59                 ext2_sync_super(sb, es, 1);
60         }
61
62         va_start(args, fmt);
63
64         vaf.fmt = fmt;
65         vaf.va = &args;
66
67         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
68                sb->s_id, function, &vaf);
69
70         va_end(args);
71
72         if (test_opt(sb, ERRORS_PANIC))
73                 panic("EXT2-fs: panic from previous error\n");
74         if (test_opt(sb, ERRORS_RO)) {
75                 ext2_msg(sb, KERN_CRIT,
76                              "error: remounting filesystem read-only");
77                 sb->s_flags |= MS_RDONLY;
78         }
79 }
80
81 void ext2_msg(struct super_block *sb, const char *prefix,
82                 const char *fmt, ...)
83 {
84         struct va_format vaf;
85         va_list args;
86
87         va_start(args, fmt);
88
89         vaf.fmt = fmt;
90         vaf.va = &args;
91
92         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
93
94         va_end(args);
95 }
96
97 /*
98  * This must be called with sbi->s_lock held.
99  */
100 void ext2_update_dynamic_rev(struct super_block *sb)
101 {
102         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
103
104         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
105                 return;
106
107         ext2_msg(sb, KERN_WARNING,
108                      "warning: updating to rev %d because of "
109                      "new feature flag, running e2fsck is recommended",
110                      EXT2_DYNAMIC_REV);
111
112         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
113         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
114         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
115         /* leave es->s_feature_*compat flags alone */
116         /* es->s_uuid will be set by e2fsck if empty */
117
118         /*
119          * The rest of the superblock fields should be zero, and if not it
120          * means they are likely already in use, so leave them alone.  We
121          * can leave it up to e2fsck to clean up any inconsistencies there.
122          */
123 }
124
125 static void ext2_put_super (struct super_block * sb)
126 {
127         int db_count;
128         int i;
129         struct ext2_sb_info *sbi = EXT2_SB(sb);
130
131         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
132
133         if (sb->s_dirt)
134                 ext2_write_super(sb);
135
136         ext2_xattr_put_super(sb);
137         if (!(sb->s_flags & MS_RDONLY)) {
138                 struct ext2_super_block *es = sbi->s_es;
139
140                 spin_lock(&sbi->s_lock);
141                 es->s_state = cpu_to_le16(sbi->s_mount_state);
142                 spin_unlock(&sbi->s_lock);
143                 ext2_sync_super(sb, es, 1);
144         }
145         db_count = sbi->s_gdb_count;
146         for (i = 0; i < db_count; i++)
147                 if (sbi->s_group_desc[i])
148                         brelse (sbi->s_group_desc[i]);
149         kfree(sbi->s_group_desc);
150         kfree(sbi->s_debts);
151         percpu_counter_destroy(&sbi->s_freeblocks_counter);
152         percpu_counter_destroy(&sbi->s_freeinodes_counter);
153         percpu_counter_destroy(&sbi->s_dirs_counter);
154         brelse (sbi->s_sbh);
155         sb->s_fs_info = NULL;
156         kfree(sbi->s_blockgroup_lock);
157         kfree(sbi);
158 }
159
160 static struct kmem_cache * ext2_inode_cachep;
161
162 static struct inode *ext2_alloc_inode(struct super_block *sb)
163 {
164         struct ext2_inode_info *ei;
165         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
166         if (!ei)
167                 return NULL;
168         ei->i_block_alloc_info = NULL;
169         ei->vfs_inode.i_version = 1;
170         return &ei->vfs_inode;
171 }
172
173 static void ext2_destroy_inode(struct inode *inode)
174 {
175         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
176 }
177
178 static void init_once(void *foo)
179 {
180         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
181
182         rwlock_init(&ei->i_meta_lock);
183 #ifdef CONFIG_EXT2_FS_XATTR
184         init_rwsem(&ei->xattr_sem);
185 #endif
186         mutex_init(&ei->truncate_mutex);
187         inode_init_once(&ei->vfs_inode);
188 }
189
190 static int init_inodecache(void)
191 {
192         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
193                                              sizeof(struct ext2_inode_info),
194                                              0, (SLAB_RECLAIM_ACCOUNT|
195                                                 SLAB_MEM_SPREAD),
196                                              init_once);
197         if (ext2_inode_cachep == NULL)
198                 return -ENOMEM;
199         return 0;
200 }
201
202 static void destroy_inodecache(void)
203 {
204         kmem_cache_destroy(ext2_inode_cachep);
205 }
206
207 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
208 {
209         struct super_block *sb = vfs->mnt_sb;
210         struct ext2_sb_info *sbi = EXT2_SB(sb);
211         struct ext2_super_block *es = sbi->s_es;
212         unsigned long def_mount_opts;
213
214         spin_lock(&sbi->s_lock);
215         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
216
217         if (sbi->s_sb_block != 1)
218                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
219         if (test_opt(sb, MINIX_DF))
220                 seq_puts(seq, ",minixdf");
221         if (test_opt(sb, GRPID))
222                 seq_puts(seq, ",grpid");
223         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
224                 seq_puts(seq, ",nogrpid");
225         if (sbi->s_resuid != EXT2_DEF_RESUID ||
226             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
227                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
228         }
229         if (sbi->s_resgid != EXT2_DEF_RESGID ||
230             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
231                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
232         }
233         if (test_opt(sb, ERRORS_RO)) {
234                 int def_errors = le16_to_cpu(es->s_errors);
235
236                 if (def_errors == EXT2_ERRORS_PANIC ||
237                     def_errors == EXT2_ERRORS_CONTINUE) {
238                         seq_puts(seq, ",errors=remount-ro");
239                 }
240         }
241         if (test_opt(sb, ERRORS_CONT))
242                 seq_puts(seq, ",errors=continue");
243         if (test_opt(sb, ERRORS_PANIC))
244                 seq_puts(seq, ",errors=panic");
245         if (test_opt(sb, NO_UID32))
246                 seq_puts(seq, ",nouid32");
247         if (test_opt(sb, DEBUG))
248                 seq_puts(seq, ",debug");
249         if (test_opt(sb, OLDALLOC))
250                 seq_puts(seq, ",oldalloc");
251
252 #ifdef CONFIG_EXT2_FS_XATTR
253         if (test_opt(sb, XATTR_USER))
254                 seq_puts(seq, ",user_xattr");
255         if (!test_opt(sb, XATTR_USER) &&
256             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
257                 seq_puts(seq, ",nouser_xattr");
258         }
259 #endif
260
261 #ifdef CONFIG_EXT2_FS_POSIX_ACL
262         if (test_opt(sb, POSIX_ACL))
263                 seq_puts(seq, ",acl");
264         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
265                 seq_puts(seq, ",noacl");
266 #endif
267
268         if (test_opt(sb, NOBH))
269                 seq_puts(seq, ",nobh");
270
271 #if defined(CONFIG_QUOTA)
272         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
273                 seq_puts(seq, ",usrquota");
274
275         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
276                 seq_puts(seq, ",grpquota");
277 #endif
278
279 #if defined(CONFIG_EXT2_FS_XIP)
280         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
281                 seq_puts(seq, ",xip");
282 #endif
283
284         if (!test_opt(sb, RESERVATION))
285                 seq_puts(seq, ",noreservation");
286
287         spin_unlock(&sbi->s_lock);
288         return 0;
289 }
290
291 #ifdef CONFIG_QUOTA
292 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
293 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
294 #endif
295
296 static const struct super_operations ext2_sops = {
297         .alloc_inode    = ext2_alloc_inode,
298         .destroy_inode  = ext2_destroy_inode,
299         .write_inode    = ext2_write_inode,
300         .evict_inode    = ext2_evict_inode,
301         .put_super      = ext2_put_super,
302         .write_super    = ext2_write_super,
303         .sync_fs        = ext2_sync_fs,
304         .statfs         = ext2_statfs,
305         .remount_fs     = ext2_remount,
306         .show_options   = ext2_show_options,
307 #ifdef CONFIG_QUOTA
308         .quota_read     = ext2_quota_read,
309         .quota_write    = ext2_quota_write,
310 #endif
311 };
312
313 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
314                 u64 ino, u32 generation)
315 {
316         struct inode *inode;
317
318         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
319                 return ERR_PTR(-ESTALE);
320         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
321                 return ERR_PTR(-ESTALE);
322
323         /* iget isn't really right if the inode is currently unallocated!!
324          * ext2_read_inode currently does appropriate checks, but
325          * it might be "neater" to call ext2_get_inode first and check
326          * if the inode is valid.....
327          */
328         inode = ext2_iget(sb, ino);
329         if (IS_ERR(inode))
330                 return ERR_CAST(inode);
331         if (generation && inode->i_generation != generation) {
332                 /* we didn't find the right inode.. */
333                 iput(inode);
334                 return ERR_PTR(-ESTALE);
335         }
336         return inode;
337 }
338
339 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
340                 int fh_len, int fh_type)
341 {
342         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
343                                     ext2_nfs_get_inode);
344 }
345
346 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
347                 int fh_len, int fh_type)
348 {
349         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
350                                     ext2_nfs_get_inode);
351 }
352
353 /* Yes, most of these are left as NULL!!
354  * A NULL value implies the default, which works with ext2-like file
355  * systems, but can be improved upon.
356  * Currently only get_parent is required.
357  */
358 static const struct export_operations ext2_export_ops = {
359         .fh_to_dentry = ext2_fh_to_dentry,
360         .fh_to_parent = ext2_fh_to_parent,
361         .get_parent = ext2_get_parent,
362 };
363
364 static unsigned long get_sb_block(void **data)
365 {
366         unsigned long   sb_block;
367         char            *options = (char *) *data;
368
369         if (!options || strncmp(options, "sb=", 3) != 0)
370                 return 1;       /* Default location */
371         options += 3;
372         sb_block = simple_strtoul(options, &options, 0);
373         if (*options && *options != ',') {
374                 printk("EXT2-fs: Invalid sb specification: %s\n",
375                        (char *) *data);
376                 return 1;
377         }
378         if (*options == ',')
379                 options++;
380         *data = (void *) options;
381         return sb_block;
382 }
383
384 enum {
385         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
386         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
387         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
388         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
389         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
390         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
391 };
392
393 static const match_table_t tokens = {
394         {Opt_bsd_df, "bsddf"},
395         {Opt_minix_df, "minixdf"},
396         {Opt_grpid, "grpid"},
397         {Opt_grpid, "bsdgroups"},
398         {Opt_nogrpid, "nogrpid"},
399         {Opt_nogrpid, "sysvgroups"},
400         {Opt_resgid, "resgid=%u"},
401         {Opt_resuid, "resuid=%u"},
402         {Opt_sb, "sb=%u"},
403         {Opt_err_cont, "errors=continue"},
404         {Opt_err_panic, "errors=panic"},
405         {Opt_err_ro, "errors=remount-ro"},
406         {Opt_nouid32, "nouid32"},
407         {Opt_nocheck, "check=none"},
408         {Opt_nocheck, "nocheck"},
409         {Opt_debug, "debug"},
410         {Opt_oldalloc, "oldalloc"},
411         {Opt_orlov, "orlov"},
412         {Opt_nobh, "nobh"},
413         {Opt_user_xattr, "user_xattr"},
414         {Opt_nouser_xattr, "nouser_xattr"},
415         {Opt_acl, "acl"},
416         {Opt_noacl, "noacl"},
417         {Opt_xip, "xip"},
418         {Opt_grpquota, "grpquota"},
419         {Opt_ignore, "noquota"},
420         {Opt_quota, "quota"},
421         {Opt_usrquota, "usrquota"},
422         {Opt_reservation, "reservation"},
423         {Opt_noreservation, "noreservation"},
424         {Opt_err, NULL}
425 };
426
427 static int parse_options(char *options, struct super_block *sb)
428 {
429         char *p;
430         struct ext2_sb_info *sbi = EXT2_SB(sb);
431         substring_t args[MAX_OPT_ARGS];
432         int option;
433
434         if (!options)
435                 return 1;
436
437         while ((p = strsep (&options, ",")) != NULL) {
438                 int token;
439                 if (!*p)
440                         continue;
441
442                 token = match_token(p, tokens, args);
443                 switch (token) {
444                 case Opt_bsd_df:
445                         clear_opt (sbi->s_mount_opt, MINIX_DF);
446                         break;
447                 case Opt_minix_df:
448                         set_opt (sbi->s_mount_opt, MINIX_DF);
449                         break;
450                 case Opt_grpid:
451                         set_opt (sbi->s_mount_opt, GRPID);
452                         break;
453                 case Opt_nogrpid:
454                         clear_opt (sbi->s_mount_opt, GRPID);
455                         break;
456                 case Opt_resuid:
457                         if (match_int(&args[0], &option))
458                                 return 0;
459                         sbi->s_resuid = option;
460                         break;
461                 case Opt_resgid:
462                         if (match_int(&args[0], &option))
463                                 return 0;
464                         sbi->s_resgid = option;
465                         break;
466                 case Opt_sb:
467                         /* handled by get_sb_block() instead of here */
468                         /* *sb_block = match_int(&args[0]); */
469                         break;
470                 case Opt_err_panic:
471                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
472                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
473                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
474                         break;
475                 case Opt_err_ro:
476                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
477                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
478                         set_opt (sbi->s_mount_opt, ERRORS_RO);
479                         break;
480                 case Opt_err_cont:
481                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
482                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
483                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
484                         break;
485                 case Opt_nouid32:
486                         set_opt (sbi->s_mount_opt, NO_UID32);
487                         break;
488                 case Opt_nocheck:
489                         clear_opt (sbi->s_mount_opt, CHECK);
490                         break;
491                 case Opt_debug:
492                         set_opt (sbi->s_mount_opt, DEBUG);
493                         break;
494                 case Opt_oldalloc:
495                         set_opt (sbi->s_mount_opt, OLDALLOC);
496                         break;
497                 case Opt_orlov:
498                         clear_opt (sbi->s_mount_opt, OLDALLOC);
499                         break;
500                 case Opt_nobh:
501                         set_opt (sbi->s_mount_opt, NOBH);
502                         break;
503 #ifdef CONFIG_EXT2_FS_XATTR
504                 case Opt_user_xattr:
505                         set_opt (sbi->s_mount_opt, XATTR_USER);
506                         break;
507                 case Opt_nouser_xattr:
508                         clear_opt (sbi->s_mount_opt, XATTR_USER);
509                         break;
510 #else
511                 case Opt_user_xattr:
512                 case Opt_nouser_xattr:
513                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
514                                 "not supported");
515                         break;
516 #endif
517 #ifdef CONFIG_EXT2_FS_POSIX_ACL
518                 case Opt_acl:
519                         set_opt(sbi->s_mount_opt, POSIX_ACL);
520                         break;
521                 case Opt_noacl:
522                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
523                         break;
524 #else
525                 case Opt_acl:
526                 case Opt_noacl:
527                         ext2_msg(sb, KERN_INFO,
528                                 "(no)acl options not supported");
529                         break;
530 #endif
531                 case Opt_xip:
532 #ifdef CONFIG_EXT2_FS_XIP
533                         set_opt (sbi->s_mount_opt, XIP);
534 #else
535                         ext2_msg(sb, KERN_INFO, "xip option not supported");
536 #endif
537                         break;
538
539 #if defined(CONFIG_QUOTA)
540                 case Opt_quota:
541                 case Opt_usrquota:
542                         set_opt(sbi->s_mount_opt, USRQUOTA);
543                         break;
544
545                 case Opt_grpquota:
546                         set_opt(sbi->s_mount_opt, GRPQUOTA);
547                         break;
548 #else
549                 case Opt_quota:
550                 case Opt_usrquota:
551                 case Opt_grpquota:
552                         ext2_msg(sb, KERN_INFO,
553                                 "quota operations not supported");
554                         break;
555 #endif
556
557                 case Opt_reservation:
558                         set_opt(sbi->s_mount_opt, RESERVATION);
559                         ext2_msg(sb, KERN_INFO, "reservations ON");
560                         break;
561                 case Opt_noreservation:
562                         clear_opt(sbi->s_mount_opt, RESERVATION);
563                         ext2_msg(sb, KERN_INFO, "reservations OFF");
564                         break;
565                 case Opt_ignore:
566                         break;
567                 default:
568                         return 0;
569                 }
570         }
571         return 1;
572 }
573
574 static int ext2_setup_super (struct super_block * sb,
575                               struct ext2_super_block * es,
576                               int read_only)
577 {
578         int res = 0;
579         struct ext2_sb_info *sbi = EXT2_SB(sb);
580
581         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
582                 ext2_msg(sb, KERN_ERR,
583                         "error: revision level too high, "
584                         "forcing read-only mode");
585                 res = MS_RDONLY;
586         }
587         if (read_only)
588                 return res;
589         if (!(sbi->s_mount_state & EXT2_VALID_FS))
590                 ext2_msg(sb, KERN_WARNING,
591                         "warning: mounting unchecked fs, "
592                         "running e2fsck is recommended");
593         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
594                 ext2_msg(sb, KERN_WARNING,
595                         "warning: mounting fs with errors, "
596                         "running e2fsck is recommended");
597         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
598                  le16_to_cpu(es->s_mnt_count) >=
599                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
600                 ext2_msg(sb, KERN_WARNING,
601                         "warning: maximal mount count reached, "
602                         "running e2fsck is recommended");
603         else if (le32_to_cpu(es->s_checkinterval) &&
604                 (le32_to_cpu(es->s_lastcheck) +
605                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
606                 ext2_msg(sb, KERN_WARNING,
607                         "warning: checktime reached, "
608                         "running e2fsck is recommended");
609         if (!le16_to_cpu(es->s_max_mnt_count))
610                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
611         le16_add_cpu(&es->s_mnt_count, 1);
612         if (test_opt (sb, DEBUG))
613                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
614                         "bpg=%lu, ipg=%lu, mo=%04lx]",
615                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
616                         sbi->s_frag_size,
617                         sbi->s_groups_count,
618                         EXT2_BLOCKS_PER_GROUP(sb),
619                         EXT2_INODES_PER_GROUP(sb),
620                         sbi->s_mount_opt);
621         return res;
622 }
623
624 static int ext2_check_descriptors(struct super_block *sb)
625 {
626         int i;
627         struct ext2_sb_info *sbi = EXT2_SB(sb);
628
629         ext2_debug ("Checking group descriptors");
630
631         for (i = 0; i < sbi->s_groups_count; i++) {
632                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
633                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
634                 ext2_fsblk_t last_block;
635
636                 if (i == sbi->s_groups_count - 1)
637                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
638                 else
639                         last_block = first_block +
640                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
641
642                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
643                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
644                 {
645                         ext2_error (sb, "ext2_check_descriptors",
646                                     "Block bitmap for group %d"
647                                     " not in group (block %lu)!",
648                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
649                         return 0;
650                 }
651                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
652                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
653                 {
654                         ext2_error (sb, "ext2_check_descriptors",
655                                     "Inode bitmap for group %d"
656                                     " not in group (block %lu)!",
657                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
658                         return 0;
659                 }
660                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
661                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
662                     last_block)
663                 {
664                         ext2_error (sb, "ext2_check_descriptors",
665                                     "Inode table for group %d"
666                                     " not in group (block %lu)!",
667                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
668                         return 0;
669                 }
670         }
671         return 1;
672 }
673
674 /*
675  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
676  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
677  * We need to be 1 filesystem block less than the 2^32 sector limit.
678  */
679 static loff_t ext2_max_size(int bits)
680 {
681         loff_t res = EXT2_NDIR_BLOCKS;
682         int meta_blocks;
683         loff_t upper_limit;
684
685         /* This is calculated to be the largest file size for a
686          * dense, file such that the total number of
687          * sectors in the file, including data and all indirect blocks,
688          * does not exceed 2^32 -1
689          * __u32 i_blocks representing the total number of
690          * 512 bytes blocks of the file
691          */
692         upper_limit = (1LL << 32) - 1;
693
694         /* total blocks in file system block size */
695         upper_limit >>= (bits - 9);
696
697
698         /* indirect blocks */
699         meta_blocks = 1;
700         /* double indirect blocks */
701         meta_blocks += 1 + (1LL << (bits-2));
702         /* tripple indirect blocks */
703         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
704
705         upper_limit -= meta_blocks;
706         upper_limit <<= bits;
707
708         res += 1LL << (bits-2);
709         res += 1LL << (2*(bits-2));
710         res += 1LL << (3*(bits-2));
711         res <<= bits;
712         if (res > upper_limit)
713                 res = upper_limit;
714
715         if (res > MAX_LFS_FILESIZE)
716                 res = MAX_LFS_FILESIZE;
717
718         return res;
719 }
720
721 static unsigned long descriptor_loc(struct super_block *sb,
722                                     unsigned long logic_sb_block,
723                                     int nr)
724 {
725         struct ext2_sb_info *sbi = EXT2_SB(sb);
726         unsigned long bg, first_meta_bg;
727         int has_super = 0;
728         
729         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
730
731         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
732             nr < first_meta_bg)
733                 return (logic_sb_block + nr + 1);
734         bg = sbi->s_desc_per_block * nr;
735         if (ext2_bg_has_super(sb, bg))
736                 has_super = 1;
737
738         return ext2_group_first_block_no(sb, bg) + has_super;
739 }
740
741 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
742 {
743         struct buffer_head * bh;
744         struct ext2_sb_info * sbi;
745         struct ext2_super_block * es;
746         struct inode *root;
747         unsigned long block;
748         unsigned long sb_block = get_sb_block(&data);
749         unsigned long logic_sb_block;
750         unsigned long offset = 0;
751         unsigned long def_mount_opts;
752         long ret = -EINVAL;
753         int blocksize = BLOCK_SIZE;
754         int db_count;
755         int i, j;
756         __le32 features;
757         int err;
758
759         err = -ENOMEM;
760         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
761         if (!sbi)
762                 goto failed_unlock;
763
764         sbi->s_blockgroup_lock =
765                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
766         if (!sbi->s_blockgroup_lock) {
767                 kfree(sbi);
768                 goto failed_unlock;
769         }
770         sb->s_fs_info = sbi;
771         sbi->s_sb_block = sb_block;
772
773         spin_lock_init(&sbi->s_lock);
774
775         /*
776          * See what the current blocksize for the device is, and
777          * use that as the blocksize.  Otherwise (or if the blocksize
778          * is smaller than the default) use the default.
779          * This is important for devices that have a hardware
780          * sectorsize that is larger than the default.
781          */
782         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
783         if (!blocksize) {
784                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
785                 goto failed_sbi;
786         }
787
788         /*
789          * If the superblock doesn't start on a hardware sector boundary,
790          * calculate the offset.  
791          */
792         if (blocksize != BLOCK_SIZE) {
793                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
794                 offset = (sb_block*BLOCK_SIZE) % blocksize;
795         } else {
796                 logic_sb_block = sb_block;
797         }
798
799         if (!(bh = sb_bread(sb, logic_sb_block))) {
800                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
801                 goto failed_sbi;
802         }
803         /*
804          * Note: s_es must be initialized as soon as possible because
805          *       some ext2 macro-instructions depend on its value
806          */
807         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
808         sbi->s_es = es;
809         sb->s_magic = le16_to_cpu(es->s_magic);
810
811         if (sb->s_magic != EXT2_SUPER_MAGIC)
812                 goto cantfind_ext2;
813
814         /* Set defaults before we parse the mount options */
815         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
816         if (def_mount_opts & EXT2_DEFM_DEBUG)
817                 set_opt(sbi->s_mount_opt, DEBUG);
818         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
819                 set_opt(sbi->s_mount_opt, GRPID);
820         if (def_mount_opts & EXT2_DEFM_UID16)
821                 set_opt(sbi->s_mount_opt, NO_UID32);
822 #ifdef CONFIG_EXT2_FS_XATTR
823         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
824                 set_opt(sbi->s_mount_opt, XATTR_USER);
825 #endif
826 #ifdef CONFIG_EXT2_FS_POSIX_ACL
827         if (def_mount_opts & EXT2_DEFM_ACL)
828                 set_opt(sbi->s_mount_opt, POSIX_ACL);
829 #endif
830         
831         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
832                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
833         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
834                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
835         else
836                 set_opt(sbi->s_mount_opt, ERRORS_RO);
837
838         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
839         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
840         
841         set_opt(sbi->s_mount_opt, RESERVATION);
842
843         if (!parse_options((char *) data, sb))
844                 goto failed_mount;
845
846         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
847                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
848                  MS_POSIXACL : 0);
849
850         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
851                                     EXT2_MOUNT_XIP if not */
852
853         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
854             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
855              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
856              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
857                 ext2_msg(sb, KERN_WARNING,
858                         "warning: feature flags set on rev 0 fs, "
859                         "running e2fsck is recommended");
860         /*
861          * Check feature flags regardless of the revision level, since we
862          * previously didn't change the revision level when setting the flags,
863          * so there is a chance incompat flags are set on a rev 0 filesystem.
864          */
865         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
866         if (features) {
867                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
868                        "unsupported optional features (%x)",
869                         le32_to_cpu(features));
870                 goto failed_mount;
871         }
872         if (!(sb->s_flags & MS_RDONLY) &&
873             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
874                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
875                        "unsupported optional features (%x)",
876                        le32_to_cpu(features));
877                 goto failed_mount;
878         }
879
880         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
881
882         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
883                 if (!silent)
884                         ext2_msg(sb, KERN_ERR,
885                                 "error: unsupported blocksize for xip");
886                 goto failed_mount;
887         }
888
889         /* If the blocksize doesn't match, re-read the thing.. */
890         if (sb->s_blocksize != blocksize) {
891                 brelse(bh);
892
893                 if (!sb_set_blocksize(sb, blocksize)) {
894                         ext2_msg(sb, KERN_ERR, "error: blocksize is too small");
895                         goto failed_sbi;
896                 }
897
898                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
899                 offset = (sb_block*BLOCK_SIZE) % blocksize;
900                 bh = sb_bread(sb, logic_sb_block);
901                 if(!bh) {
902                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
903                                 "superblock on 2nd try");
904                         goto failed_sbi;
905                 }
906                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
907                 sbi->s_es = es;
908                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
909                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
910                         goto failed_mount;
911                 }
912         }
913
914         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
915
916         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
917                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
918                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
919         } else {
920                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
921                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
922                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
923                     !is_power_of_2(sbi->s_inode_size) ||
924                     (sbi->s_inode_size > blocksize)) {
925                         ext2_msg(sb, KERN_ERR,
926                                 "error: unsupported inode size: %d",
927                                 sbi->s_inode_size);
928                         goto failed_mount;
929                 }
930         }
931
932         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
933                                    le32_to_cpu(es->s_log_frag_size);
934         if (sbi->s_frag_size == 0)
935                 goto cantfind_ext2;
936         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
937
938         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
939         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
940         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
941
942         if (EXT2_INODE_SIZE(sb) == 0)
943                 goto cantfind_ext2;
944         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
945         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
946                 goto cantfind_ext2;
947         sbi->s_itb_per_group = sbi->s_inodes_per_group /
948                                         sbi->s_inodes_per_block;
949         sbi->s_desc_per_block = sb->s_blocksize /
950                                         sizeof (struct ext2_group_desc);
951         sbi->s_sbh = bh;
952         sbi->s_mount_state = le16_to_cpu(es->s_state);
953         sbi->s_addr_per_block_bits =
954                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
955         sbi->s_desc_per_block_bits =
956                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
957
958         if (sb->s_magic != EXT2_SUPER_MAGIC)
959                 goto cantfind_ext2;
960
961         if (sb->s_blocksize != bh->b_size) {
962                 if (!silent)
963                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
964                 goto failed_mount;
965         }
966
967         if (sb->s_blocksize != sbi->s_frag_size) {
968                 ext2_msg(sb, KERN_ERR,
969                         "error: fragsize %lu != blocksize %lu"
970                         "(not supported yet)",
971                         sbi->s_frag_size, sb->s_blocksize);
972                 goto failed_mount;
973         }
974
975         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
976                 ext2_msg(sb, KERN_ERR,
977                         "error: #blocks per group too big: %lu",
978                         sbi->s_blocks_per_group);
979                 goto failed_mount;
980         }
981         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
982                 ext2_msg(sb, KERN_ERR,
983                         "error: #fragments per group too big: %lu",
984                         sbi->s_frags_per_group);
985                 goto failed_mount;
986         }
987         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
988                 ext2_msg(sb, KERN_ERR,
989                         "error: #inodes per group too big: %lu",
990                         sbi->s_inodes_per_group);
991                 goto failed_mount;
992         }
993
994         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
995                 goto cantfind_ext2;
996         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
997                                 le32_to_cpu(es->s_first_data_block) - 1)
998                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
999         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1000                    EXT2_DESC_PER_BLOCK(sb);
1001         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1002         if (sbi->s_group_desc == NULL) {
1003                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1004                 goto failed_mount;
1005         }
1006         bgl_lock_init(sbi->s_blockgroup_lock);
1007         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1008         if (!sbi->s_debts) {
1009                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1010                 goto failed_mount_group_desc;
1011         }
1012         for (i = 0; i < db_count; i++) {
1013                 block = descriptor_loc(sb, logic_sb_block, i);
1014                 sbi->s_group_desc[i] = sb_bread(sb, block);
1015                 if (!sbi->s_group_desc[i]) {
1016                         for (j = 0; j < i; j++)
1017                                 brelse (sbi->s_group_desc[j]);
1018                         ext2_msg(sb, KERN_ERR,
1019                                 "error: unable to read group descriptors");
1020                         goto failed_mount_group_desc;
1021                 }
1022         }
1023         if (!ext2_check_descriptors (sb)) {
1024                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1025                 goto failed_mount2;
1026         }
1027         sbi->s_gdb_count = db_count;
1028         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1029         spin_lock_init(&sbi->s_next_gen_lock);
1030
1031         /* per fileystem reservation list head & lock */
1032         spin_lock_init(&sbi->s_rsv_window_lock);
1033         sbi->s_rsv_window_root = RB_ROOT;
1034         /*
1035          * Add a single, static dummy reservation to the start of the
1036          * reservation window list --- it gives us a placeholder for
1037          * append-at-start-of-list which makes the allocation logic
1038          * _much_ simpler.
1039          */
1040         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1041         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1042         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1043         sbi->s_rsv_window_head.rsv_goal_size = 0;
1044         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1045
1046         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1047                                 ext2_count_free_blocks(sb));
1048         if (!err) {
1049                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1050                                 ext2_count_free_inodes(sb));
1051         }
1052         if (!err) {
1053                 err = percpu_counter_init(&sbi->s_dirs_counter,
1054                                 ext2_count_dirs(sb));
1055         }
1056         if (err) {
1057                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1058                 goto failed_mount3;
1059         }
1060         /*
1061          * set up enough so that it can read an inode
1062          */
1063         sb->s_op = &ext2_sops;
1064         sb->s_export_op = &ext2_export_ops;
1065         sb->s_xattr = ext2_xattr_handlers;
1066
1067 #ifdef CONFIG_QUOTA
1068         sb->dq_op = &dquot_operations;
1069         sb->s_qcop = &dquot_quotactl_ops;
1070 #endif
1071
1072         root = ext2_iget(sb, EXT2_ROOT_INO);
1073         if (IS_ERR(root)) {
1074                 ret = PTR_ERR(root);
1075                 goto failed_mount3;
1076         }
1077         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1078                 iput(root);
1079                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1080                 goto failed_mount3;
1081         }
1082
1083         sb->s_root = d_alloc_root(root);
1084         if (!sb->s_root) {
1085                 iput(root);
1086                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1087                 ret = -ENOMEM;
1088                 goto failed_mount3;
1089         }
1090         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1091                 ext2_msg(sb, KERN_WARNING,
1092                         "warning: mounting ext3 filesystem as ext2");
1093         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1094                 sb->s_flags |= MS_RDONLY;
1095         ext2_write_super(sb);
1096         return 0;
1097
1098 cantfind_ext2:
1099         if (!silent)
1100                 ext2_msg(sb, KERN_ERR,
1101                         "error: can't find an ext2 filesystem on dev %s.",
1102                         sb->s_id);
1103         goto failed_mount;
1104 failed_mount3:
1105         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1106         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1107         percpu_counter_destroy(&sbi->s_dirs_counter);
1108 failed_mount2:
1109         for (i = 0; i < db_count; i++)
1110                 brelse(sbi->s_group_desc[i]);
1111 failed_mount_group_desc:
1112         kfree(sbi->s_group_desc);
1113         kfree(sbi->s_debts);
1114 failed_mount:
1115         brelse(bh);
1116 failed_sbi:
1117         sb->s_fs_info = NULL;
1118         kfree(sbi->s_blockgroup_lock);
1119         kfree(sbi);
1120 failed_unlock:
1121         return ret;
1122 }
1123
1124 static void ext2_clear_super_error(struct super_block *sb)
1125 {
1126         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1127
1128         if (buffer_write_io_error(sbh)) {
1129                 /*
1130                  * Oh, dear.  A previous attempt to write the
1131                  * superblock failed.  This could happen because the
1132                  * USB device was yanked out.  Or it could happen to
1133                  * be a transient write error and maybe the block will
1134                  * be remapped.  Nothing we can do but to retry the
1135                  * write and hope for the best.
1136                  */
1137                 ext2_msg(sb, KERN_ERR,
1138                        "previous I/O error to superblock detected\n");
1139                 clear_buffer_write_io_error(sbh);
1140                 set_buffer_uptodate(sbh);
1141         }
1142 }
1143
1144 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1145                             int wait)
1146 {
1147         ext2_clear_super_error(sb);
1148         spin_lock(&EXT2_SB(sb)->s_lock);
1149         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1150         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1151         es->s_wtime = cpu_to_le32(get_seconds());
1152         /* unlock before we do IO */
1153         spin_unlock(&EXT2_SB(sb)->s_lock);
1154         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1155         if (wait)
1156                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1157         sb->s_dirt = 0;
1158 }
1159
1160 /*
1161  * In the second extended file system, it is not necessary to
1162  * write the super block since we use a mapping of the
1163  * disk super block in a buffer.
1164  *
1165  * However, this function is still used to set the fs valid
1166  * flags to 0.  We need to set this flag to 0 since the fs
1167  * may have been checked while mounted and e2fsck may have
1168  * set s_state to EXT2_VALID_FS after some corrections.
1169  */
1170 static int ext2_sync_fs(struct super_block *sb, int wait)
1171 {
1172         struct ext2_sb_info *sbi = EXT2_SB(sb);
1173         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1174
1175         spin_lock(&sbi->s_lock);
1176         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1177                 ext2_debug("setting valid to 0\n");
1178                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1179         }
1180         spin_unlock(&sbi->s_lock);
1181         ext2_sync_super(sb, es, wait);
1182         return 0;
1183 }
1184
1185
1186 void ext2_write_super(struct super_block *sb)
1187 {
1188         if (!(sb->s_flags & MS_RDONLY))
1189                 ext2_sync_fs(sb, 1);
1190         else
1191                 sb->s_dirt = 0;
1192 }
1193
1194 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1195 {
1196         struct ext2_sb_info * sbi = EXT2_SB(sb);
1197         struct ext2_super_block * es;
1198         unsigned long old_mount_opt = sbi->s_mount_opt;
1199         struct ext2_mount_options old_opts;
1200         unsigned long old_sb_flags;
1201         int err;
1202
1203         spin_lock(&sbi->s_lock);
1204
1205         /* Store the old options */
1206         old_sb_flags = sb->s_flags;
1207         old_opts.s_mount_opt = sbi->s_mount_opt;
1208         old_opts.s_resuid = sbi->s_resuid;
1209         old_opts.s_resgid = sbi->s_resgid;
1210
1211         /*
1212          * Allow the "check" option to be passed as a remount option.
1213          */
1214         if (!parse_options(data, sb)) {
1215                 err = -EINVAL;
1216                 goto restore_opts;
1217         }
1218
1219         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1220                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1221
1222         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1223                                     EXT2_MOUNT_XIP if not */
1224
1225         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1226                 ext2_msg(sb, KERN_WARNING,
1227                         "warning: unsupported blocksize for xip");
1228                 err = -EINVAL;
1229                 goto restore_opts;
1230         }
1231
1232         es = sbi->s_es;
1233         if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1234                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1235                          "xip flag with busy inodes while remounting");
1236                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1237                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1238         }
1239         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1240                 spin_unlock(&sbi->s_lock);
1241                 return 0;
1242         }
1243         if (*flags & MS_RDONLY) {
1244                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1245                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1246                         spin_unlock(&sbi->s_lock);
1247                         return 0;
1248                 }
1249
1250                 /*
1251                  * OK, we are remounting a valid rw partition rdonly, so set
1252                  * the rdonly flag and then mark the partition as valid again.
1253                  */
1254                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1255                 es->s_mtime = cpu_to_le32(get_seconds());
1256                 spin_unlock(&sbi->s_lock);
1257
1258                 err = dquot_suspend(sb, -1);
1259                 if (err < 0) {
1260                         spin_lock(&sbi->s_lock);
1261                         goto restore_opts;
1262                 }
1263
1264                 ext2_sync_super(sb, es, 1);
1265         } else {
1266                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1267                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1268                 if (ret) {
1269                         ext2_msg(sb, KERN_WARNING,
1270                                 "warning: couldn't remount RDWR because of "
1271                                 "unsupported optional features (%x).",
1272                                 le32_to_cpu(ret));
1273                         err = -EROFS;
1274                         goto restore_opts;
1275                 }
1276                 /*
1277                  * Mounting a RDONLY partition read-write, so reread and
1278                  * store the current valid flag.  (It may have been changed
1279                  * by e2fsck since we originally mounted the partition.)
1280                  */
1281                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1282                 if (!ext2_setup_super (sb, es, 0))
1283                         sb->s_flags &= ~MS_RDONLY;
1284                 spin_unlock(&sbi->s_lock);
1285
1286                 ext2_write_super(sb);
1287
1288                 dquot_resume(sb, -1);
1289         }
1290
1291         return 0;
1292 restore_opts:
1293         sbi->s_mount_opt = old_opts.s_mount_opt;
1294         sbi->s_resuid = old_opts.s_resuid;
1295         sbi->s_resgid = old_opts.s_resgid;
1296         sb->s_flags = old_sb_flags;
1297         spin_unlock(&sbi->s_lock);
1298         return err;
1299 }
1300
1301 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1302 {
1303         struct super_block *sb = dentry->d_sb;
1304         struct ext2_sb_info *sbi = EXT2_SB(sb);
1305         struct ext2_super_block *es = sbi->s_es;
1306         u64 fsid;
1307
1308         spin_lock(&sbi->s_lock);
1309
1310         if (test_opt (sb, MINIX_DF))
1311                 sbi->s_overhead_last = 0;
1312         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1313                 unsigned long i, overhead = 0;
1314                 smp_rmb();
1315
1316                 /*
1317                  * Compute the overhead (FS structures). This is constant
1318                  * for a given filesystem unless the number of block groups
1319                  * changes so we cache the previous value until it does.
1320                  */
1321
1322                 /*
1323                  * All of the blocks before first_data_block are
1324                  * overhead
1325                  */
1326                 overhead = le32_to_cpu(es->s_first_data_block);
1327
1328                 /*
1329                  * Add the overhead attributed to the superblock and
1330                  * block group descriptors.  If the sparse superblocks
1331                  * feature is turned on, then not all groups have this.
1332                  */
1333                 for (i = 0; i < sbi->s_groups_count; i++)
1334                         overhead += ext2_bg_has_super(sb, i) +
1335                                 ext2_bg_num_gdb(sb, i);
1336
1337                 /*
1338                  * Every block group has an inode bitmap, a block
1339                  * bitmap, and an inode table.
1340                  */
1341                 overhead += (sbi->s_groups_count *
1342                              (2 + sbi->s_itb_per_group));
1343                 sbi->s_overhead_last = overhead;
1344                 smp_wmb();
1345                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1346         }
1347
1348         buf->f_type = EXT2_SUPER_MAGIC;
1349         buf->f_bsize = sb->s_blocksize;
1350         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1351         buf->f_bfree = ext2_count_free_blocks(sb);
1352         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1353         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1354         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1355                 buf->f_bavail = 0;
1356         buf->f_files = le32_to_cpu(es->s_inodes_count);
1357         buf->f_ffree = ext2_count_free_inodes(sb);
1358         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1359         buf->f_namelen = EXT2_NAME_LEN;
1360         fsid = le64_to_cpup((void *)es->s_uuid) ^
1361                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1362         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1363         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1364         spin_unlock(&sbi->s_lock);
1365         return 0;
1366 }
1367
1368 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1369         int flags, const char *dev_name, void *data)
1370 {
1371         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1372 }
1373
1374 #ifdef CONFIG_QUOTA
1375
1376 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1377  * acquiring the locks... As quota files are never truncated and quota code
1378  * itself serializes the operations (and noone else should touch the files)
1379  * we don't have to be afraid of races */
1380 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1381                                size_t len, loff_t off)
1382 {
1383         struct inode *inode = sb_dqopt(sb)->files[type];
1384         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1385         int err = 0;
1386         int offset = off & (sb->s_blocksize - 1);
1387         int tocopy;
1388         size_t toread;
1389         struct buffer_head tmp_bh;
1390         struct buffer_head *bh;
1391         loff_t i_size = i_size_read(inode);
1392
1393         if (off > i_size)
1394                 return 0;
1395         if (off+len > i_size)
1396                 len = i_size-off;
1397         toread = len;
1398         while (toread > 0) {
1399                 tocopy = sb->s_blocksize - offset < toread ?
1400                                 sb->s_blocksize - offset : toread;
1401
1402                 tmp_bh.b_state = 0;
1403                 tmp_bh.b_size = sb->s_blocksize;
1404                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1405                 if (err < 0)
1406                         return err;
1407                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1408                         memset(data, 0, tocopy);
1409                 else {
1410                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1411                         if (!bh)
1412                                 return -EIO;
1413                         memcpy(data, bh->b_data+offset, tocopy);
1414                         brelse(bh);
1415                 }
1416                 offset = 0;
1417                 toread -= tocopy;
1418                 data += tocopy;
1419                 blk++;
1420         }
1421         return len;
1422 }
1423
1424 /* Write to quotafile */
1425 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1426                                 const char *data, size_t len, loff_t off)
1427 {
1428         struct inode *inode = sb_dqopt(sb)->files[type];
1429         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1430         int err = 0;
1431         int offset = off & (sb->s_blocksize - 1);
1432         int tocopy;
1433         size_t towrite = len;
1434         struct buffer_head tmp_bh;
1435         struct buffer_head *bh;
1436
1437         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1438         while (towrite > 0) {
1439                 tocopy = sb->s_blocksize - offset < towrite ?
1440                                 sb->s_blocksize - offset : towrite;
1441
1442                 tmp_bh.b_state = 0;
1443                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1444                 if (err < 0)
1445                         goto out;
1446                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1447                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1448                 else
1449                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1450                 if (!bh) {
1451                         err = -EIO;
1452                         goto out;
1453                 }
1454                 lock_buffer(bh);
1455                 memcpy(bh->b_data+offset, data, tocopy);
1456                 flush_dcache_page(bh->b_page);
1457                 set_buffer_uptodate(bh);
1458                 mark_buffer_dirty(bh);
1459                 unlock_buffer(bh);
1460                 brelse(bh);
1461                 offset = 0;
1462                 towrite -= tocopy;
1463                 data += tocopy;
1464                 blk++;
1465         }
1466 out:
1467         if (len == towrite) {
1468                 mutex_unlock(&inode->i_mutex);
1469                 return err;
1470         }
1471         if (inode->i_size < off+len-towrite)
1472                 i_size_write(inode, off+len-towrite);
1473         inode->i_version++;
1474         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1475         mark_inode_dirty(inode);
1476         mutex_unlock(&inode->i_mutex);
1477         return len - towrite;
1478 }
1479
1480 #endif
1481
1482 static struct file_system_type ext2_fs_type = {
1483         .owner          = THIS_MODULE,
1484         .name           = "ext2",
1485         .mount          = ext2_mount,
1486         .kill_sb        = kill_block_super,
1487         .fs_flags       = FS_REQUIRES_DEV,
1488 };
1489
1490 static int __init init_ext2_fs(void)
1491 {
1492         int err = init_ext2_xattr();
1493         if (err)
1494                 return err;
1495         err = init_inodecache();
1496         if (err)
1497                 goto out1;
1498         err = register_filesystem(&ext2_fs_type);
1499         if (err)
1500                 goto out;
1501         return 0;
1502 out:
1503         destroy_inodecache();
1504 out1:
1505         exit_ext2_xattr();
1506         return err;
1507 }
1508
1509 static void __exit exit_ext2_fs(void)
1510 {
1511         unregister_filesystem(&ext2_fs_type);
1512         destroy_inodecache();
1513         exit_ext2_xattr();
1514 }
1515
1516 module_init(init_ext2_fs)
1517 module_exit(exit_ext2_fs)