[PATCH] ext2: print xip mount option in ext2_show_options
[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/config.h>
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/slab.h>
24 #include <linux/init.h>
25 #include <linux/blkdev.h>
26 #include <linux/parser.h>
27 #include <linux/random.h>
28 #include <linux/buffer_head.h>
29 #include <linux/smp_lock.h>
30 #include <linux/vfs.h>
31 #include <linux/seq_file.h>
32 #include <linux/mount.h>
33 #include <asm/uaccess.h>
34 #include "ext2.h"
35 #include "xattr.h"
36 #include "acl.h"
37 #include "xip.h"
38
39 static void ext2_sync_super(struct super_block *sb,
40                             struct ext2_super_block *es);
41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
42 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf);
43
44 void ext2_error (struct super_block * sb, const char * function,
45                  const char * fmt, ...)
46 {
47         va_list args;
48         struct ext2_sb_info *sbi = EXT2_SB(sb);
49         struct ext2_super_block *es = sbi->s_es;
50
51         if (!(sb->s_flags & MS_RDONLY)) {
52                 sbi->s_mount_state |= EXT2_ERROR_FS;
53                 es->s_state =
54                         cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
55                 ext2_sync_super(sb, es);
56         }
57
58         va_start(args, fmt);
59         printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
60         vprintk(fmt, args);
61         printk("\n");
62         va_end(args);
63
64         if (test_opt(sb, ERRORS_PANIC))
65                 panic("EXT2-fs panic from previous error\n");
66         if (test_opt(sb, ERRORS_RO)) {
67                 printk("Remounting filesystem read-only\n");
68                 sb->s_flags |= MS_RDONLY;
69         }
70 }
71
72 void ext2_warning (struct super_block * sb, const char * function,
73                    const char * fmt, ...)
74 {
75         va_list args;
76
77         va_start(args, fmt);
78         printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
79                sb->s_id, function);
80         vprintk(fmt, args);
81         printk("\n");
82         va_end(args);
83 }
84
85 void ext2_update_dynamic_rev(struct super_block *sb)
86 {
87         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
88
89         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
90                 return;
91
92         ext2_warning(sb, __FUNCTION__,
93                      "updating to rev %d because of new feature flag, "
94                      "running e2fsck is recommended",
95                      EXT2_DYNAMIC_REV);
96
97         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
98         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
99         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
100         /* leave es->s_feature_*compat flags alone */
101         /* es->s_uuid will be set by e2fsck if empty */
102
103         /*
104          * The rest of the superblock fields should be zero, and if not it
105          * means they are likely already in use, so leave them alone.  We
106          * can leave it up to e2fsck to clean up any inconsistencies there.
107          */
108 }
109
110 static void ext2_put_super (struct super_block * sb)
111 {
112         int db_count;
113         int i;
114         struct ext2_sb_info *sbi = EXT2_SB(sb);
115
116         ext2_xattr_put_super(sb);
117         if (!(sb->s_flags & MS_RDONLY)) {
118                 struct ext2_super_block *es = sbi->s_es;
119
120                 es->s_state = cpu_to_le16(sbi->s_mount_state);
121                 ext2_sync_super(sb, es);
122         }
123         db_count = sbi->s_gdb_count;
124         for (i = 0; i < db_count; i++)
125                 if (sbi->s_group_desc[i])
126                         brelse (sbi->s_group_desc[i]);
127         kfree(sbi->s_group_desc);
128         kfree(sbi->s_debts);
129         percpu_counter_destroy(&sbi->s_freeblocks_counter);
130         percpu_counter_destroy(&sbi->s_freeinodes_counter);
131         percpu_counter_destroy(&sbi->s_dirs_counter);
132         brelse (sbi->s_sbh);
133         sb->s_fs_info = NULL;
134         kfree(sbi);
135
136         return;
137 }
138
139 static kmem_cache_t * ext2_inode_cachep;
140
141 static struct inode *ext2_alloc_inode(struct super_block *sb)
142 {
143         struct ext2_inode_info *ei;
144         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
145         if (!ei)
146                 return NULL;
147 #ifdef CONFIG_EXT2_FS_POSIX_ACL
148         ei->i_acl = EXT2_ACL_NOT_CACHED;
149         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
150 #endif
151         ei->vfs_inode.i_version = 1;
152         return &ei->vfs_inode;
153 }
154
155 static void ext2_destroy_inode(struct inode *inode)
156 {
157         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
158 }
159
160 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
161 {
162         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
163
164         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
165             SLAB_CTOR_CONSTRUCTOR) {
166                 rwlock_init(&ei->i_meta_lock);
167 #ifdef CONFIG_EXT2_FS_XATTR
168                 init_rwsem(&ei->xattr_sem);
169 #endif
170                 inode_init_once(&ei->vfs_inode);
171         }
172 }
173  
174 static int init_inodecache(void)
175 {
176         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
177                                              sizeof(struct ext2_inode_info),
178                                              0, SLAB_RECLAIM_ACCOUNT,
179                                              init_once, NULL);
180         if (ext2_inode_cachep == NULL)
181                 return -ENOMEM;
182         return 0;
183 }
184
185 static void destroy_inodecache(void)
186 {
187         if (kmem_cache_destroy(ext2_inode_cachep))
188                 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
189 }
190
191 static void ext2_clear_inode(struct inode *inode)
192 {
193 #ifdef CONFIG_EXT2_FS_POSIX_ACL
194         struct ext2_inode_info *ei = EXT2_I(inode);
195
196         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
197                 posix_acl_release(ei->i_acl);
198                 ei->i_acl = EXT2_ACL_NOT_CACHED;
199         }
200         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
201                 posix_acl_release(ei->i_default_acl);
202                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
203         }
204 #endif
205 }
206
207 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
208 {
209         struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
210
211         if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
212                 seq_puts(seq, ",grpid");
213         else
214                 seq_puts(seq, ",nogrpid");
215
216 #if defined(CONFIG_QUOTA)
217         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
218                 seq_puts(seq, ",usrquota");
219
220         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
221                 seq_puts(seq, ",grpquota");
222 #endif
223
224 #if defined(CONFIG_EXT2_FS_XIP)
225         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
226                 seq_puts(seq, ",xip");
227 #endif
228
229         return 0;
230 }
231
232 #ifdef CONFIG_QUOTA
233 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
234 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
235 #endif
236
237 static struct super_operations ext2_sops = {
238         .alloc_inode    = ext2_alloc_inode,
239         .destroy_inode  = ext2_destroy_inode,
240         .read_inode     = ext2_read_inode,
241         .write_inode    = ext2_write_inode,
242         .put_inode      = ext2_put_inode,
243         .delete_inode   = ext2_delete_inode,
244         .put_super      = ext2_put_super,
245         .write_super    = ext2_write_super,
246         .statfs         = ext2_statfs,
247         .remount_fs     = ext2_remount,
248         .clear_inode    = ext2_clear_inode,
249         .show_options   = ext2_show_options,
250 #ifdef CONFIG_QUOTA
251         .quota_read     = ext2_quota_read,
252         .quota_write    = ext2_quota_write,
253 #endif
254 };
255
256 /* Yes, most of these are left as NULL!!
257  * A NULL value implies the default, which works with ext2-like file
258  * systems, but can be improved upon.
259  * Currently only get_parent is required.
260  */
261 struct dentry *ext2_get_parent(struct dentry *child);
262 static struct export_operations ext2_export_ops = {
263         .get_parent = ext2_get_parent,
264 };
265
266 static unsigned long get_sb_block(void **data)
267 {
268         unsigned long   sb_block;
269         char            *options = (char *) *data;
270
271         if (!options || strncmp(options, "sb=", 3) != 0)
272                 return 1;       /* Default location */
273         options += 3;
274         sb_block = simple_strtoul(options, &options, 0);
275         if (*options && *options != ',') {
276                 printk("EXT2-fs: Invalid sb specification: %s\n",
277                        (char *) *data);
278                 return 1;
279         }
280         if (*options == ',')
281                 options++;
282         *data = (void *) options;
283         return sb_block;
284 }
285
286 enum {
287         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
288         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
289         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
290         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
291         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
292         Opt_usrquota, Opt_grpquota
293 };
294
295 static match_table_t tokens = {
296         {Opt_bsd_df, "bsddf"},
297         {Opt_minix_df, "minixdf"},
298         {Opt_grpid, "grpid"},
299         {Opt_grpid, "bsdgroups"},
300         {Opt_nogrpid, "nogrpid"},
301         {Opt_nogrpid, "sysvgroups"},
302         {Opt_resgid, "resgid=%u"},
303         {Opt_resuid, "resuid=%u"},
304         {Opt_sb, "sb=%u"},
305         {Opt_err_cont, "errors=continue"},
306         {Opt_err_panic, "errors=panic"},
307         {Opt_err_ro, "errors=remount-ro"},
308         {Opt_nouid32, "nouid32"},
309         {Opt_nocheck, "check=none"},
310         {Opt_nocheck, "nocheck"},
311         {Opt_debug, "debug"},
312         {Opt_oldalloc, "oldalloc"},
313         {Opt_orlov, "orlov"},
314         {Opt_nobh, "nobh"},
315         {Opt_user_xattr, "user_xattr"},
316         {Opt_nouser_xattr, "nouser_xattr"},
317         {Opt_acl, "acl"},
318         {Opt_noacl, "noacl"},
319         {Opt_xip, "xip"},
320         {Opt_grpquota, "grpquota"},
321         {Opt_ignore, "noquota"},
322         {Opt_quota, "quota"},
323         {Opt_usrquota, "usrquota"},
324         {Opt_err, NULL}
325 };
326
327 static int parse_options (char * options,
328                           struct ext2_sb_info *sbi)
329 {
330         char * p;
331         substring_t args[MAX_OPT_ARGS];
332         unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
333         int option;
334
335         if (!options)
336                 return 1;
337
338         while ((p = strsep (&options, ",")) != NULL) {
339                 int token;
340                 if (!*p)
341                         continue;
342
343                 token = match_token(p, tokens, args);
344                 switch (token) {
345                 case Opt_bsd_df:
346                         clear_opt (sbi->s_mount_opt, MINIX_DF);
347                         break;
348                 case Opt_minix_df:
349                         set_opt (sbi->s_mount_opt, MINIX_DF);
350                         break;
351                 case Opt_grpid:
352                         set_opt (sbi->s_mount_opt, GRPID);
353                         break;
354                 case Opt_nogrpid:
355                         clear_opt (sbi->s_mount_opt, GRPID);
356                         break;
357                 case Opt_resuid:
358                         if (match_int(&args[0], &option))
359                                 return 0;
360                         sbi->s_resuid = option;
361                         break;
362                 case Opt_resgid:
363                         if (match_int(&args[0], &option))
364                                 return 0;
365                         sbi->s_resgid = option;
366                         break;
367                 case Opt_sb:
368                         /* handled by get_sb_block() instead of here */
369                         /* *sb_block = match_int(&args[0]); */
370                         break;
371                 case Opt_err_panic:
372                         kind = EXT2_MOUNT_ERRORS_PANIC;
373                         break;
374                 case Opt_err_ro:
375                         kind = EXT2_MOUNT_ERRORS_RO;
376                         break;
377                 case Opt_err_cont:
378                         kind = EXT2_MOUNT_ERRORS_CONT;
379                         break;
380                 case Opt_nouid32:
381                         set_opt (sbi->s_mount_opt, NO_UID32);
382                         break;
383                 case Opt_nocheck:
384                         clear_opt (sbi->s_mount_opt, CHECK);
385                         break;
386                 case Opt_debug:
387                         set_opt (sbi->s_mount_opt, DEBUG);
388                         break;
389                 case Opt_oldalloc:
390                         set_opt (sbi->s_mount_opt, OLDALLOC);
391                         break;
392                 case Opt_orlov:
393                         clear_opt (sbi->s_mount_opt, OLDALLOC);
394                         break;
395                 case Opt_nobh:
396                         set_opt (sbi->s_mount_opt, NOBH);
397                         break;
398 #ifdef CONFIG_EXT2_FS_XATTR
399                 case Opt_user_xattr:
400                         set_opt (sbi->s_mount_opt, XATTR_USER);
401                         break;
402                 case Opt_nouser_xattr:
403                         clear_opt (sbi->s_mount_opt, XATTR_USER);
404                         break;
405 #else
406                 case Opt_user_xattr:
407                 case Opt_nouser_xattr:
408                         printk("EXT2 (no)user_xattr options not supported\n");
409                         break;
410 #endif
411 #ifdef CONFIG_EXT2_FS_POSIX_ACL
412                 case Opt_acl:
413                         set_opt(sbi->s_mount_opt, POSIX_ACL);
414                         break;
415                 case Opt_noacl:
416                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
417                         break;
418 #else
419                 case Opt_acl:
420                 case Opt_noacl:
421                         printk("EXT2 (no)acl options not supported\n");
422                         break;
423 #endif
424                 case Opt_xip:
425 #ifdef CONFIG_EXT2_FS_XIP
426                         set_opt (sbi->s_mount_opt, XIP);
427 #else
428                         printk("EXT2 xip option not supported\n");
429 #endif
430                         break;
431
432 #if defined(CONFIG_QUOTA)
433                 case Opt_quota:
434                 case Opt_usrquota:
435                         set_opt(sbi->s_mount_opt, USRQUOTA);
436                         break;
437
438                 case Opt_grpquota:
439                         set_opt(sbi->s_mount_opt, GRPQUOTA);
440                         break;
441 #else
442                 case Opt_quota:
443                 case Opt_usrquota:
444                 case Opt_grpquota:
445                         printk(KERN_ERR
446                                 "EXT2-fs: quota operations not supported.\n");
447
448                         break;
449 #endif
450
451                 case Opt_ignore:
452                         break;
453                 default:
454                         return 0;
455                 }
456         }
457         sbi->s_mount_opt |= kind;
458         return 1;
459 }
460
461 static int ext2_setup_super (struct super_block * sb,
462                               struct ext2_super_block * es,
463                               int read_only)
464 {
465         int res = 0;
466         struct ext2_sb_info *sbi = EXT2_SB(sb);
467
468         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
469                 printk ("EXT2-fs warning: revision level too high, "
470                         "forcing read-only mode\n");
471                 res = MS_RDONLY;
472         }
473         if (read_only)
474                 return res;
475         if (!(sbi->s_mount_state & EXT2_VALID_FS))
476                 printk ("EXT2-fs warning: mounting unchecked fs, "
477                         "running e2fsck is recommended\n");
478         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
479                 printk ("EXT2-fs warning: mounting fs with errors, "
480                         "running e2fsck is recommended\n");
481         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
482                  le16_to_cpu(es->s_mnt_count) >=
483                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
484                 printk ("EXT2-fs warning: maximal mount count reached, "
485                         "running e2fsck is recommended\n");
486         else if (le32_to_cpu(es->s_checkinterval) &&
487                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
488                 printk ("EXT2-fs warning: checktime reached, "
489                         "running e2fsck is recommended\n");
490         if (!le16_to_cpu(es->s_max_mnt_count))
491                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
492         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
493         ext2_write_super(sb);
494         if (test_opt (sb, DEBUG))
495                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
496                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
497                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
498                         sbi->s_frag_size,
499                         sbi->s_groups_count,
500                         EXT2_BLOCKS_PER_GROUP(sb),
501                         EXT2_INODES_PER_GROUP(sb),
502                         sbi->s_mount_opt);
503         return res;
504 }
505
506 static int ext2_check_descriptors (struct super_block * sb)
507 {
508         int i;
509         int desc_block = 0;
510         struct ext2_sb_info *sbi = EXT2_SB(sb);
511         unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
512         struct ext2_group_desc * gdp = NULL;
513
514         ext2_debug ("Checking group descriptors");
515
516         for (i = 0; i < sbi->s_groups_count; i++)
517         {
518                 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
519                         gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
520                 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
521                     le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
522                 {
523                         ext2_error (sb, "ext2_check_descriptors",
524                                     "Block bitmap for group %d"
525                                     " not in group (block %lu)!",
526                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
527                         return 0;
528                 }
529                 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
530                     le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
531                 {
532                         ext2_error (sb, "ext2_check_descriptors",
533                                     "Inode bitmap for group %d"
534                                     " not in group (block %lu)!",
535                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
536                         return 0;
537                 }
538                 if (le32_to_cpu(gdp->bg_inode_table) < block ||
539                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
540                     block + EXT2_BLOCKS_PER_GROUP(sb))
541                 {
542                         ext2_error (sb, "ext2_check_descriptors",
543                                     "Inode table for group %d"
544                                     " not in group (block %lu)!",
545                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
546                         return 0;
547                 }
548                 block += EXT2_BLOCKS_PER_GROUP(sb);
549                 gdp++;
550         }
551         return 1;
552 }
553
554 #define log2(n) ffz(~(n))
555  
556 /*
557  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
558  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
559  * We need to be 1 filesystem block less than the 2^32 sector limit.
560  */
561 static loff_t ext2_max_size(int bits)
562 {
563         loff_t res = EXT2_NDIR_BLOCKS;
564         /* This constant is calculated to be the largest file size for a
565          * dense, 4k-blocksize file such that the total number of
566          * sectors in the file, including data and all indirect blocks,
567          * does not exceed 2^32. */
568         const loff_t upper_limit = 0x1ff7fffd000LL;
569
570         res += 1LL << (bits-2);
571         res += 1LL << (2*(bits-2));
572         res += 1LL << (3*(bits-2));
573         res <<= bits;
574         if (res > upper_limit)
575                 res = upper_limit;
576         return res;
577 }
578
579 static unsigned long descriptor_loc(struct super_block *sb,
580                                     unsigned long logic_sb_block,
581                                     int nr)
582 {
583         struct ext2_sb_info *sbi = EXT2_SB(sb);
584         unsigned long bg, first_data_block, first_meta_bg;
585         int has_super = 0;
586         
587         first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
588         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
589
590         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
591             nr < first_meta_bg)
592                 return (logic_sb_block + nr + 1);
593         bg = sbi->s_desc_per_block * nr;
594         if (ext2_bg_has_super(sb, bg))
595                 has_super = 1;
596         return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
597 }
598
599 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
600 {
601         struct buffer_head * bh;
602         struct ext2_sb_info * sbi;
603         struct ext2_super_block * es;
604         struct inode *root;
605         unsigned long block;
606         unsigned long sb_block = get_sb_block(&data);
607         unsigned long logic_sb_block;
608         unsigned long offset = 0;
609         unsigned long def_mount_opts;
610         int blocksize = BLOCK_SIZE;
611         int db_count;
612         int i, j;
613         __le32 features;
614
615         sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
616         if (!sbi)
617                 return -ENOMEM;
618         sb->s_fs_info = sbi;
619         memset(sbi, 0, sizeof(*sbi));
620
621         /*
622          * See what the current blocksize for the device is, and
623          * use that as the blocksize.  Otherwise (or if the blocksize
624          * is smaller than the default) use the default.
625          * This is important for devices that have a hardware
626          * sectorsize that is larger than the default.
627          */
628         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
629         if (!blocksize) {
630                 printk ("EXT2-fs: unable to set blocksize\n");
631                 goto failed_sbi;
632         }
633
634         /*
635          * If the superblock doesn't start on a hardware sector boundary,
636          * calculate the offset.  
637          */
638         if (blocksize != BLOCK_SIZE) {
639                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
640                 offset = (sb_block*BLOCK_SIZE) % blocksize;
641         } else {
642                 logic_sb_block = sb_block;
643         }
644
645         if (!(bh = sb_bread(sb, logic_sb_block))) {
646                 printk ("EXT2-fs: unable to read superblock\n");
647                 goto failed_sbi;
648         }
649         /*
650          * Note: s_es must be initialized as soon as possible because
651          *       some ext2 macro-instructions depend on its value
652          */
653         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
654         sbi->s_es = es;
655         sb->s_magic = le16_to_cpu(es->s_magic);
656
657         if (sb->s_magic != EXT2_SUPER_MAGIC)
658                 goto cantfind_ext2;
659
660         /* Set defaults before we parse the mount options */
661         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
662         if (def_mount_opts & EXT2_DEFM_DEBUG)
663                 set_opt(sbi->s_mount_opt, DEBUG);
664         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
665                 set_opt(sbi->s_mount_opt, GRPID);
666         if (def_mount_opts & EXT2_DEFM_UID16)
667                 set_opt(sbi->s_mount_opt, NO_UID32);
668         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
669                 set_opt(sbi->s_mount_opt, XATTR_USER);
670         if (def_mount_opts & EXT2_DEFM_ACL)
671                 set_opt(sbi->s_mount_opt, POSIX_ACL);
672         
673         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
674                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
675         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
676                 set_opt(sbi->s_mount_opt, ERRORS_RO);
677
678         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
679         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
680         
681         if (!parse_options ((char *) data, sbi))
682                 goto failed_mount;
683
684         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
685                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
686                  MS_POSIXACL : 0);
687
688         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
689                                     EXT2_MOUNT_XIP if not */
690
691         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
692             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
693              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
694              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
695                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
696                        "running e2fsck is recommended\n");
697         /*
698          * Check feature flags regardless of the revision level, since we
699          * previously didn't change the revision level when setting the flags,
700          * so there is a chance incompat flags are set on a rev 0 filesystem.
701          */
702         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
703         if (features) {
704                 printk("EXT2-fs: %s: couldn't mount because of "
705                        "unsupported optional features (%x).\n",
706                        sb->s_id, le32_to_cpu(features));
707                 goto failed_mount;
708         }
709         if (!(sb->s_flags & MS_RDONLY) &&
710             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
711                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
712                        "unsupported optional features (%x).\n",
713                        sb->s_id, le32_to_cpu(features));
714                 goto failed_mount;
715         }
716
717         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
718
719         if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
720                                   (sb->s_blocksize != blocksize))) {
721                 if (!silent)
722                         printk("XIP: Unsupported blocksize\n");
723                 goto failed_mount;
724         }
725
726         /* If the blocksize doesn't match, re-read the thing.. */
727         if (sb->s_blocksize != blocksize) {
728                 brelse(bh);
729
730                 if (!sb_set_blocksize(sb, blocksize)) {
731                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
732                         goto failed_sbi;
733                 }
734
735                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
736                 offset = (sb_block*BLOCK_SIZE) % blocksize;
737                 bh = sb_bread(sb, logic_sb_block);
738                 if(!bh) {
739                         printk("EXT2-fs: Couldn't read superblock on "
740                                "2nd try.\n");
741                         goto failed_sbi;
742                 }
743                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
744                 sbi->s_es = es;
745                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
746                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
747                         goto failed_mount;
748                 }
749         }
750
751         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
752
753         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
754                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
755                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
756         } else {
757                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
758                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
759                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
760                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
761                     (sbi->s_inode_size > blocksize)) {
762                         printk ("EXT2-fs: unsupported inode size: %d\n",
763                                 sbi->s_inode_size);
764                         goto failed_mount;
765                 }
766         }
767
768         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
769                                    le32_to_cpu(es->s_log_frag_size);
770         if (sbi->s_frag_size == 0)
771                 goto cantfind_ext2;
772         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
773
774         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
775         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
776         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
777
778         if (EXT2_INODE_SIZE(sb) == 0)
779                 goto cantfind_ext2;
780         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
781         if (sbi->s_inodes_per_block == 0)
782                 goto cantfind_ext2;
783         sbi->s_itb_per_group = sbi->s_inodes_per_group /
784                                         sbi->s_inodes_per_block;
785         sbi->s_desc_per_block = sb->s_blocksize /
786                                         sizeof (struct ext2_group_desc);
787         sbi->s_sbh = bh;
788         sbi->s_mount_state = le16_to_cpu(es->s_state);
789         sbi->s_addr_per_block_bits =
790                 log2 (EXT2_ADDR_PER_BLOCK(sb));
791         sbi->s_desc_per_block_bits =
792                 log2 (EXT2_DESC_PER_BLOCK(sb));
793
794         if (sb->s_magic != EXT2_SUPER_MAGIC)
795                 goto cantfind_ext2;
796
797         if (sb->s_blocksize != bh->b_size) {
798                 if (!silent)
799                         printk ("VFS: Unsupported blocksize on dev "
800                                 "%s.\n", sb->s_id);
801                 goto failed_mount;
802         }
803
804         if (sb->s_blocksize != sbi->s_frag_size) {
805                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
806                         sbi->s_frag_size, sb->s_blocksize);
807                 goto failed_mount;
808         }
809
810         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
811                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
812                         sbi->s_blocks_per_group);
813                 goto failed_mount;
814         }
815         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
816                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
817                         sbi->s_frags_per_group);
818                 goto failed_mount;
819         }
820         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
821                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
822                         sbi->s_inodes_per_group);
823                 goto failed_mount;
824         }
825
826         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
827                 goto cantfind_ext2;
828         sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
829                                         le32_to_cpu(es->s_first_data_block) +
830                                        EXT2_BLOCKS_PER_GROUP(sb) - 1) /
831                                        EXT2_BLOCKS_PER_GROUP(sb);
832         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
833                    EXT2_DESC_PER_BLOCK(sb);
834         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
835         if (sbi->s_group_desc == NULL) {
836                 printk ("EXT2-fs: not enough memory\n");
837                 goto failed_mount;
838         }
839         percpu_counter_init(&sbi->s_freeblocks_counter);
840         percpu_counter_init(&sbi->s_freeinodes_counter);
841         percpu_counter_init(&sbi->s_dirs_counter);
842         bgl_lock_init(&sbi->s_blockgroup_lock);
843         sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
844                                GFP_KERNEL);
845         if (!sbi->s_debts) {
846                 printk ("EXT2-fs: not enough memory\n");
847                 goto failed_mount_group_desc;
848         }
849         memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
850         for (i = 0; i < db_count; i++) {
851                 block = descriptor_loc(sb, logic_sb_block, i);
852                 sbi->s_group_desc[i] = sb_bread(sb, block);
853                 if (!sbi->s_group_desc[i]) {
854                         for (j = 0; j < i; j++)
855                                 brelse (sbi->s_group_desc[j]);
856                         printk ("EXT2-fs: unable to read group descriptors\n");
857                         goto failed_mount_group_desc;
858                 }
859         }
860         if (!ext2_check_descriptors (sb)) {
861                 printk ("EXT2-fs: group descriptors corrupted!\n");
862                 db_count = i;
863                 goto failed_mount2;
864         }
865         sbi->s_gdb_count = db_count;
866         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
867         spin_lock_init(&sbi->s_next_gen_lock);
868         /*
869          * set up enough so that it can read an inode
870          */
871         sb->s_op = &ext2_sops;
872         sb->s_export_op = &ext2_export_ops;
873         sb->s_xattr = ext2_xattr_handlers;
874         root = iget(sb, EXT2_ROOT_INO);
875         sb->s_root = d_alloc_root(root);
876         if (!sb->s_root) {
877                 iput(root);
878                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
879                 goto failed_mount2;
880         }
881         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
882                 dput(sb->s_root);
883                 sb->s_root = NULL;
884                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
885                 goto failed_mount2;
886         }
887         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
888                 ext2_warning(sb, __FUNCTION__,
889                         "mounting ext3 filesystem as ext2");
890         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
891         percpu_counter_mod(&sbi->s_freeblocks_counter,
892                                 ext2_count_free_blocks(sb));
893         percpu_counter_mod(&sbi->s_freeinodes_counter,
894                                 ext2_count_free_inodes(sb));
895         percpu_counter_mod(&sbi->s_dirs_counter,
896                                 ext2_count_dirs(sb));
897         return 0;
898
899 cantfind_ext2:
900         if (!silent)
901                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
902                        sb->s_id);
903         goto failed_mount;
904
905 failed_mount2:
906         for (i = 0; i < db_count; i++)
907                 brelse(sbi->s_group_desc[i]);
908 failed_mount_group_desc:
909         kfree(sbi->s_group_desc);
910         kfree(sbi->s_debts);
911 failed_mount:
912         brelse(bh);
913 failed_sbi:
914         sb->s_fs_info = NULL;
915         kfree(sbi);
916         return -EINVAL;
917 }
918
919 static void ext2_commit_super (struct super_block * sb,
920                                struct ext2_super_block * es)
921 {
922         es->s_wtime = cpu_to_le32(get_seconds());
923         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
924         sb->s_dirt = 0;
925 }
926
927 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
928 {
929         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
930         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
931         es->s_wtime = cpu_to_le32(get_seconds());
932         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
933         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
934         sb->s_dirt = 0;
935 }
936
937 /*
938  * In the second extended file system, it is not necessary to
939  * write the super block since we use a mapping of the
940  * disk super block in a buffer.
941  *
942  * However, this function is still used to set the fs valid
943  * flags to 0.  We need to set this flag to 0 since the fs
944  * may have been checked while mounted and e2fsck may have
945  * set s_state to EXT2_VALID_FS after some corrections.
946  */
947
948 void ext2_write_super (struct super_block * sb)
949 {
950         struct ext2_super_block * es;
951         lock_kernel();
952         if (!(sb->s_flags & MS_RDONLY)) {
953                 es = EXT2_SB(sb)->s_es;
954
955                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
956                         ext2_debug ("setting valid to 0\n");
957                         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
958                                                   ~EXT2_VALID_FS);
959                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
960                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
961                         es->s_mtime = cpu_to_le32(get_seconds());
962                         ext2_sync_super(sb, es);
963                 } else
964                         ext2_commit_super (sb, es);
965         }
966         sb->s_dirt = 0;
967         unlock_kernel();
968 }
969
970 static int ext2_remount (struct super_block * sb, int * flags, char * data)
971 {
972         struct ext2_sb_info * sbi = EXT2_SB(sb);
973         struct ext2_super_block * es;
974         unsigned long old_mount_opt = sbi->s_mount_opt;
975         struct ext2_mount_options old_opts;
976         unsigned long old_sb_flags;
977         int err;
978
979         /* Store the old options */
980         old_sb_flags = sb->s_flags;
981         old_opts.s_mount_opt = sbi->s_mount_opt;
982         old_opts.s_resuid = sbi->s_resuid;
983         old_opts.s_resgid = sbi->s_resgid;
984
985         /*
986          * Allow the "check" option to be passed as a remount option.
987          */
988         if (!parse_options (data, sbi)) {
989                 err = -EINVAL;
990                 goto restore_opts;
991         }
992
993         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
994                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
995
996         es = sbi->s_es;
997         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
998             (old_mount_opt & EXT2_MOUNT_XIP)) &&
999             invalidate_inodes(sb))
1000                 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1001                              "xip remain in cache (no functional problem)");
1002         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1003                 return 0;
1004         if (*flags & MS_RDONLY) {
1005                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1006                     !(sbi->s_mount_state & EXT2_VALID_FS))
1007                         return 0;
1008                 /*
1009                  * OK, we are remounting a valid rw partition rdonly, so set
1010                  * the rdonly flag and then mark the partition as valid again.
1011                  */
1012                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1013                 es->s_mtime = cpu_to_le32(get_seconds());
1014         } else {
1015                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1016                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1017                 if (ret) {
1018                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
1019                                "unsupported optional features (%x).\n",
1020                                sb->s_id, le32_to_cpu(ret));
1021                         err = -EROFS;
1022                         goto restore_opts;
1023                 }
1024                 /*
1025                  * Mounting a RDONLY partition read-write, so reread and
1026                  * store the current valid flag.  (It may have been changed
1027                  * by e2fsck since we originally mounted the partition.)
1028                  */
1029                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1030                 if (!ext2_setup_super (sb, es, 0))
1031                         sb->s_flags &= ~MS_RDONLY;
1032         }
1033         ext2_sync_super(sb, es);
1034         return 0;
1035 restore_opts:
1036         sbi->s_mount_opt = old_opts.s_mount_opt;
1037         sbi->s_resuid = old_opts.s_resuid;
1038         sbi->s_resgid = old_opts.s_resgid;
1039         sb->s_flags = old_sb_flags;
1040         return err;
1041 }
1042
1043 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
1044 {
1045         struct ext2_sb_info *sbi = EXT2_SB(sb);
1046         unsigned long overhead;
1047         int i;
1048
1049         if (test_opt (sb, MINIX_DF))
1050                 overhead = 0;
1051         else {
1052                 /*
1053                  * Compute the overhead (FS structures)
1054                  */
1055
1056                 /*
1057                  * All of the blocks before first_data_block are
1058                  * overhead
1059                  */
1060                 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
1061
1062                 /*
1063                  * Add the overhead attributed to the superblock and
1064                  * block group descriptors.  If the sparse superblocks
1065                  * feature is turned on, then not all groups have this.
1066                  */
1067                 for (i = 0; i < sbi->s_groups_count; i++)
1068                         overhead += ext2_bg_has_super(sb, i) +
1069                                 ext2_bg_num_gdb(sb, i);
1070
1071                 /*
1072                  * Every block group has an inode bitmap, a block
1073                  * bitmap, and an inode table.
1074                  */
1075                 overhead += (sbi->s_groups_count *
1076                              (2 + sbi->s_itb_per_group));
1077         }
1078
1079         buf->f_type = EXT2_SUPER_MAGIC;
1080         buf->f_bsize = sb->s_blocksize;
1081         buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1082         buf->f_bfree = ext2_count_free_blocks(sb);
1083         buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1084         if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1085                 buf->f_bavail = 0;
1086         buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1087         buf->f_ffree = ext2_count_free_inodes (sb);
1088         buf->f_namelen = EXT2_NAME_LEN;
1089         return 0;
1090 }
1091
1092 static struct super_block *ext2_get_sb(struct file_system_type *fs_type,
1093         int flags, const char *dev_name, void *data)
1094 {
1095         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1096 }
1097
1098 #ifdef CONFIG_QUOTA
1099
1100 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1101  * acquiring the locks... As quota files are never truncated and quota code
1102  * itself serializes the operations (and noone else should touch the files)
1103  * we don't have to be afraid of races */
1104 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1105                                size_t len, loff_t off)
1106 {
1107         struct inode *inode = sb_dqopt(sb)->files[type];
1108         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1109         int err = 0;
1110         int offset = off & (sb->s_blocksize - 1);
1111         int tocopy;
1112         size_t toread;
1113         struct buffer_head tmp_bh;
1114         struct buffer_head *bh;
1115         loff_t i_size = i_size_read(inode);
1116
1117         if (off > i_size)
1118                 return 0;
1119         if (off+len > i_size)
1120                 len = i_size-off;
1121         toread = len;
1122         while (toread > 0) {
1123                 tocopy = sb->s_blocksize - offset < toread ?
1124                                 sb->s_blocksize - offset : toread;
1125
1126                 tmp_bh.b_state = 0;
1127                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1128                 if (err)
1129                         return err;
1130                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1131                         memset(data, 0, tocopy);
1132                 else {
1133                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1134                         if (!bh)
1135                                 return -EIO;
1136                         memcpy(data, bh->b_data+offset, tocopy);
1137                         brelse(bh);
1138                 }
1139                 offset = 0;
1140                 toread -= tocopy;
1141                 data += tocopy;
1142                 blk++;
1143         }
1144         return len;
1145 }
1146
1147 /* Write to quotafile */
1148 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1149                                 const char *data, size_t len, loff_t off)
1150 {
1151         struct inode *inode = sb_dqopt(sb)->files[type];
1152         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1153         int err = 0;
1154         int offset = off & (sb->s_blocksize - 1);
1155         int tocopy;
1156         size_t towrite = len;
1157         struct buffer_head tmp_bh;
1158         struct buffer_head *bh;
1159
1160         mutex_lock(&inode->i_mutex);
1161         while (towrite > 0) {
1162                 tocopy = sb->s_blocksize - offset < towrite ?
1163                                 sb->s_blocksize - offset : towrite;
1164
1165                 tmp_bh.b_state = 0;
1166                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1167                 if (err)
1168                         goto out;
1169                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1170                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1171                 else
1172                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1173                 if (!bh) {
1174                         err = -EIO;
1175                         goto out;
1176                 }
1177                 lock_buffer(bh);
1178                 memcpy(bh->b_data+offset, data, tocopy);
1179                 flush_dcache_page(bh->b_page);
1180                 set_buffer_uptodate(bh);
1181                 mark_buffer_dirty(bh);
1182                 unlock_buffer(bh);
1183                 brelse(bh);
1184                 offset = 0;
1185                 towrite -= tocopy;
1186                 data += tocopy;
1187                 blk++;
1188         }
1189 out:
1190         if (len == towrite)
1191                 return err;
1192         if (inode->i_size < off+len-towrite)
1193                 i_size_write(inode, off+len-towrite);
1194         inode->i_version++;
1195         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1196         mark_inode_dirty(inode);
1197         mutex_unlock(&inode->i_mutex);
1198         return len - towrite;
1199 }
1200
1201 #endif
1202
1203 static struct file_system_type ext2_fs_type = {
1204         .owner          = THIS_MODULE,
1205         .name           = "ext2",
1206         .get_sb         = ext2_get_sb,
1207         .kill_sb        = kill_block_super,
1208         .fs_flags       = FS_REQUIRES_DEV,
1209 };
1210
1211 static int __init init_ext2_fs(void)
1212 {
1213         int err = init_ext2_xattr();
1214         if (err)
1215                 return err;
1216         err = init_inodecache();
1217         if (err)
1218                 goto out1;
1219         err = register_filesystem(&ext2_fs_type);
1220         if (err)
1221                 goto out;
1222         return 0;
1223 out:
1224         destroy_inodecache();
1225 out1:
1226         exit_ext2_xattr();
1227         return err;
1228 }
1229
1230 static void __exit exit_ext2_fs(void)
1231 {
1232         unregister_filesystem(&ext2_fs_type);
1233         destroy_inodecache();
1234         exit_ext2_xattr();
1235 }
1236
1237 module_init(init_ext2_fs)
1238 module_exit(exit_ext2_fs)