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