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-rw-r--r--fs/ext2/super.c1161
1 files changed, 1161 insertions, 0 deletions
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
new file mode 100644
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+++ b/fs/ext2/super.c
@@ -0,0 +1,1161 @@
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/slab.h>
23#include <linux/init.h>
24#include <linux/blkdev.h>
25#include <linux/parser.h>
26#include <linux/random.h>
27#include <linux/buffer_head.h>
28#include <linux/smp_lock.h>
29#include <linux/vfs.h>
30#include <asm/uaccess.h>
31#include "ext2.h"
32#include "xattr.h"
33#include "acl.h"
34
35static void ext2_sync_super(struct super_block *sb,
36 struct ext2_super_block *es);
37static int ext2_remount (struct super_block * sb, int * flags, char * data);
38static int ext2_statfs (struct super_block * sb, struct kstatfs * buf);
39
40void ext2_error (struct super_block * sb, const char * function,
41 const char * fmt, ...)
42{
43 va_list args;
44 struct ext2_sb_info *sbi = EXT2_SB(sb);
45 struct ext2_super_block *es = sbi->s_es;
46
47 if (!(sb->s_flags & MS_RDONLY)) {
48 sbi->s_mount_state |= EXT2_ERROR_FS;
49 es->s_state =
50 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
51 ext2_sync_super(sb, es);
52 }
53
54 va_start(args, fmt);
55 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
56 vprintk(fmt, args);
57 printk("\n");
58 va_end(args);
59
60 if (test_opt(sb, ERRORS_PANIC))
61 panic("EXT2-fs panic from previous error\n");
62 if (test_opt(sb, ERRORS_RO)) {
63 printk("Remounting filesystem read-only\n");
64 sb->s_flags |= MS_RDONLY;
65 }
66}
67
68void ext2_warning (struct super_block * sb, const char * function,
69 const char * fmt, ...)
70{
71 va_list args;
72
73 va_start(args, fmt);
74 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
75 sb->s_id, function);
76 vprintk(fmt, args);
77 printk("\n");
78 va_end(args);
79}
80
81void ext2_update_dynamic_rev(struct super_block *sb)
82{
83 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
84
85 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
86 return;
87
88 ext2_warning(sb, __FUNCTION__,
89 "updating to rev %d because of new feature flag, "
90 "running e2fsck is recommended",
91 EXT2_DYNAMIC_REV);
92
93 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
94 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
95 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
96 /* leave es->s_feature_*compat flags alone */
97 /* es->s_uuid will be set by e2fsck if empty */
98
99 /*
100 * The rest of the superblock fields should be zero, and if not it
101 * means they are likely already in use, so leave them alone. We
102 * can leave it up to e2fsck to clean up any inconsistencies there.
103 */
104}
105
106static void ext2_put_super (struct super_block * sb)
107{
108 int db_count;
109 int i;
110 struct ext2_sb_info *sbi = EXT2_SB(sb);
111
112 ext2_xattr_put_super(sb);
113 if (!(sb->s_flags & MS_RDONLY)) {
114 struct ext2_super_block *es = sbi->s_es;
115
116 es->s_state = cpu_to_le16(sbi->s_mount_state);
117 ext2_sync_super(sb, es);
118 }
119 db_count = sbi->s_gdb_count;
120 for (i = 0; i < db_count; i++)
121 if (sbi->s_group_desc[i])
122 brelse (sbi->s_group_desc[i]);
123 kfree(sbi->s_group_desc);
124 kfree(sbi->s_debts);
125 percpu_counter_destroy(&sbi->s_freeblocks_counter);
126 percpu_counter_destroy(&sbi->s_freeinodes_counter);
127 percpu_counter_destroy(&sbi->s_dirs_counter);
128 brelse (sbi->s_sbh);
129 sb->s_fs_info = NULL;
130 kfree(sbi);
131
132 return;
133}
134
135static kmem_cache_t * ext2_inode_cachep;
136
137static struct inode *ext2_alloc_inode(struct super_block *sb)
138{
139 struct ext2_inode_info *ei;
140 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
141 if (!ei)
142 return NULL;
143#ifdef CONFIG_EXT2_FS_POSIX_ACL
144 ei->i_acl = EXT2_ACL_NOT_CACHED;
145 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
146#endif
147 ei->vfs_inode.i_version = 1;
148 return &ei->vfs_inode;
149}
150
151static void ext2_destroy_inode(struct inode *inode)
152{
153 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
154}
155
156static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
157{
158 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
159
160 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
161 SLAB_CTOR_CONSTRUCTOR) {
162 rwlock_init(&ei->i_meta_lock);
163#ifdef CONFIG_EXT2_FS_XATTR
164 init_rwsem(&ei->xattr_sem);
165#endif
166 inode_init_once(&ei->vfs_inode);
167 }
168}
169
170static int init_inodecache(void)
171{
172 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
173 sizeof(struct ext2_inode_info),
174 0, SLAB_RECLAIM_ACCOUNT,
175 init_once, NULL);
176 if (ext2_inode_cachep == NULL)
177 return -ENOMEM;
178 return 0;
179}
180
181static void destroy_inodecache(void)
182{
183 if (kmem_cache_destroy(ext2_inode_cachep))
184 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
185}
186
187static void ext2_clear_inode(struct inode *inode)
188{
189#ifdef CONFIG_EXT2_FS_POSIX_ACL
190 struct ext2_inode_info *ei = EXT2_I(inode);
191
192 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
193 posix_acl_release(ei->i_acl);
194 ei->i_acl = EXT2_ACL_NOT_CACHED;
195 }
196 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
197 posix_acl_release(ei->i_default_acl);
198 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
199 }
200#endif
201 if (!is_bad_inode(inode))
202 ext2_discard_prealloc(inode);
203}
204
205
206#ifdef CONFIG_QUOTA
207static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
208static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
209#endif
210
211static struct super_operations ext2_sops = {
212 .alloc_inode = ext2_alloc_inode,
213 .destroy_inode = ext2_destroy_inode,
214 .read_inode = ext2_read_inode,
215 .write_inode = ext2_write_inode,
216 .delete_inode = ext2_delete_inode,
217 .put_super = ext2_put_super,
218 .write_super = ext2_write_super,
219 .statfs = ext2_statfs,
220 .remount_fs = ext2_remount,
221 .clear_inode = ext2_clear_inode,
222#ifdef CONFIG_QUOTA
223 .quota_read = ext2_quota_read,
224 .quota_write = ext2_quota_write,
225#endif
226};
227
228/* Yes, most of these are left as NULL!!
229 * A NULL value implies the default, which works with ext2-like file
230 * systems, but can be improved upon.
231 * Currently only get_parent is required.
232 */
233struct dentry *ext2_get_parent(struct dentry *child);
234static struct export_operations ext2_export_ops = {
235 .get_parent = ext2_get_parent,
236};
237
238static unsigned long get_sb_block(void **data)
239{
240 unsigned long sb_block;
241 char *options = (char *) *data;
242
243 if (!options || strncmp(options, "sb=", 3) != 0)
244 return 1; /* Default location */
245 options += 3;
246 sb_block = simple_strtoul(options, &options, 0);
247 if (*options && *options != ',') {
248 printk("EXT2-fs: Invalid sb specification: %s\n",
249 (char *) *data);
250 return 1;
251 }
252 if (*options == ',')
253 options++;
254 *data = (void *) options;
255 return sb_block;
256}
257
258enum {
259 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
260 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
261 Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh,
262 Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
263 Opt_ignore, Opt_err,
264};
265
266static match_table_t tokens = {
267 {Opt_bsd_df, "bsddf"},
268 {Opt_minix_df, "minixdf"},
269 {Opt_grpid, "grpid"},
270 {Opt_grpid, "bsdgroups"},
271 {Opt_nogrpid, "nogrpid"},
272 {Opt_nogrpid, "sysvgroups"},
273 {Opt_resgid, "resgid=%u"},
274 {Opt_resuid, "resuid=%u"},
275 {Opt_sb, "sb=%u"},
276 {Opt_err_cont, "errors=continue"},
277 {Opt_err_panic, "errors=panic"},
278 {Opt_err_ro, "errors=remount-ro"},
279 {Opt_nouid32, "nouid32"},
280 {Opt_nocheck, "check=none"},
281 {Opt_nocheck, "nocheck"},
282 {Opt_check, "check"},
283 {Opt_debug, "debug"},
284 {Opt_oldalloc, "oldalloc"},
285 {Opt_orlov, "orlov"},
286 {Opt_nobh, "nobh"},
287 {Opt_user_xattr, "user_xattr"},
288 {Opt_nouser_xattr, "nouser_xattr"},
289 {Opt_acl, "acl"},
290 {Opt_noacl, "noacl"},
291 {Opt_ignore, "grpquota"},
292 {Opt_ignore, "noquota"},
293 {Opt_ignore, "quota"},
294 {Opt_ignore, "usrquota"},
295 {Opt_err, NULL}
296};
297
298static int parse_options (char * options,
299 struct ext2_sb_info *sbi)
300{
301 char * p;
302 substring_t args[MAX_OPT_ARGS];
303 unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
304 int option;
305
306 if (!options)
307 return 1;
308
309 while ((p = strsep (&options, ",")) != NULL) {
310 int token;
311 if (!*p)
312 continue;
313
314 token = match_token(p, tokens, args);
315 switch (token) {
316 case Opt_bsd_df:
317 clear_opt (sbi->s_mount_opt, MINIX_DF);
318 break;
319 case Opt_minix_df:
320 set_opt (sbi->s_mount_opt, MINIX_DF);
321 break;
322 case Opt_grpid:
323 set_opt (sbi->s_mount_opt, GRPID);
324 break;
325 case Opt_nogrpid:
326 clear_opt (sbi->s_mount_opt, GRPID);
327 break;
328 case Opt_resuid:
329 if (match_int(&args[0], &option))
330 return 0;
331 sbi->s_resuid = option;
332 break;
333 case Opt_resgid:
334 if (match_int(&args[0], &option))
335 return 0;
336 sbi->s_resgid = option;
337 break;
338 case Opt_sb:
339 /* handled by get_sb_block() instead of here */
340 /* *sb_block = match_int(&args[0]); */
341 break;
342 case Opt_err_panic:
343 kind = EXT2_MOUNT_ERRORS_PANIC;
344 break;
345 case Opt_err_ro:
346 kind = EXT2_MOUNT_ERRORS_RO;
347 break;
348 case Opt_err_cont:
349 kind = EXT2_MOUNT_ERRORS_CONT;
350 break;
351 case Opt_nouid32:
352 set_opt (sbi->s_mount_opt, NO_UID32);
353 break;
354 case Opt_check:
355#ifdef CONFIG_EXT2_CHECK
356 set_opt (sbi->s_mount_opt, CHECK);
357#else
358 printk("EXT2 Check option not supported\n");
359#endif
360 break;
361 case Opt_nocheck:
362 clear_opt (sbi->s_mount_opt, CHECK);
363 break;
364 case Opt_debug:
365 set_opt (sbi->s_mount_opt, DEBUG);
366 break;
367 case Opt_oldalloc:
368 set_opt (sbi->s_mount_opt, OLDALLOC);
369 break;
370 case Opt_orlov:
371 clear_opt (sbi->s_mount_opt, OLDALLOC);
372 break;
373 case Opt_nobh:
374 set_opt (sbi->s_mount_opt, NOBH);
375 break;
376#ifdef CONFIG_EXT2_FS_XATTR
377 case Opt_user_xattr:
378 set_opt (sbi->s_mount_opt, XATTR_USER);
379 break;
380 case Opt_nouser_xattr:
381 clear_opt (sbi->s_mount_opt, XATTR_USER);
382 break;
383#else
384 case Opt_user_xattr:
385 case Opt_nouser_xattr:
386 printk("EXT2 (no)user_xattr options not supported\n");
387 break;
388#endif
389#ifdef CONFIG_EXT2_FS_POSIX_ACL
390 case Opt_acl:
391 set_opt(sbi->s_mount_opt, POSIX_ACL);
392 break;
393 case Opt_noacl:
394 clear_opt(sbi->s_mount_opt, POSIX_ACL);
395 break;
396#else
397 case Opt_acl:
398 case Opt_noacl:
399 printk("EXT2 (no)acl options not supported\n");
400 break;
401#endif
402 case Opt_ignore:
403 break;
404 default:
405 return 0;
406 }
407 }
408 sbi->s_mount_opt |= kind;
409 return 1;
410}
411
412static int ext2_setup_super (struct super_block * sb,
413 struct ext2_super_block * es,
414 int read_only)
415{
416 int res = 0;
417 struct ext2_sb_info *sbi = EXT2_SB(sb);
418
419 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
420 printk ("EXT2-fs warning: revision level too high, "
421 "forcing read-only mode\n");
422 res = MS_RDONLY;
423 }
424 if (read_only)
425 return res;
426 if (!(sbi->s_mount_state & EXT2_VALID_FS))
427 printk ("EXT2-fs warning: mounting unchecked fs, "
428 "running e2fsck is recommended\n");
429 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
430 printk ("EXT2-fs warning: mounting fs with errors, "
431 "running e2fsck is recommended\n");
432 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
433 le16_to_cpu(es->s_mnt_count) >=
434 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
435 printk ("EXT2-fs warning: maximal mount count reached, "
436 "running e2fsck is recommended\n");
437 else if (le32_to_cpu(es->s_checkinterval) &&
438 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
439 printk ("EXT2-fs warning: checktime reached, "
440 "running e2fsck is recommended\n");
441 if (!le16_to_cpu(es->s_max_mnt_count))
442 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
443 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
444 ext2_write_super(sb);
445 if (test_opt (sb, DEBUG))
446 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
447 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
448 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
449 sbi->s_frag_size,
450 sbi->s_groups_count,
451 EXT2_BLOCKS_PER_GROUP(sb),
452 EXT2_INODES_PER_GROUP(sb),
453 sbi->s_mount_opt);
454#ifdef CONFIG_EXT2_CHECK
455 if (test_opt (sb, CHECK)) {
456 ext2_check_blocks_bitmap (sb);
457 ext2_check_inodes_bitmap (sb);
458 }
459#endif
460 return res;
461}
462
463static int ext2_check_descriptors (struct super_block * sb)
464{
465 int i;
466 int desc_block = 0;
467 struct ext2_sb_info *sbi = EXT2_SB(sb);
468 unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
469 struct ext2_group_desc * gdp = NULL;
470
471 ext2_debug ("Checking group descriptors");
472
473 for (i = 0; i < sbi->s_groups_count; i++)
474 {
475 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
476 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
477 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
478 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
479 {
480 ext2_error (sb, "ext2_check_descriptors",
481 "Block bitmap for group %d"
482 " not in group (block %lu)!",
483 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
484 return 0;
485 }
486 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
487 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
488 {
489 ext2_error (sb, "ext2_check_descriptors",
490 "Inode bitmap for group %d"
491 " not in group (block %lu)!",
492 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
493 return 0;
494 }
495 if (le32_to_cpu(gdp->bg_inode_table) < block ||
496 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
497 block + EXT2_BLOCKS_PER_GROUP(sb))
498 {
499 ext2_error (sb, "ext2_check_descriptors",
500 "Inode table for group %d"
501 " not in group (block %lu)!",
502 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
503 return 0;
504 }
505 block += EXT2_BLOCKS_PER_GROUP(sb);
506 gdp++;
507 }
508 return 1;
509}
510
511#define log2(n) ffz(~(n))
512
513/*
514 * Maximal file size. There is a direct, and {,double-,triple-}indirect
515 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
516 * We need to be 1 filesystem block less than the 2^32 sector limit.
517 */
518static loff_t ext2_max_size(int bits)
519{
520 loff_t res = EXT2_NDIR_BLOCKS;
521 /* This constant is calculated to be the largest file size for a
522 * dense, 4k-blocksize file such that the total number of
523 * sectors in the file, including data and all indirect blocks,
524 * does not exceed 2^32. */
525 const loff_t upper_limit = 0x1ff7fffd000LL;
526
527 res += 1LL << (bits-2);
528 res += 1LL << (2*(bits-2));
529 res += 1LL << (3*(bits-2));
530 res <<= bits;
531 if (res > upper_limit)
532 res = upper_limit;
533 return res;
534}
535
536static unsigned long descriptor_loc(struct super_block *sb,
537 unsigned long logic_sb_block,
538 int nr)
539{
540 struct ext2_sb_info *sbi = EXT2_SB(sb);
541 unsigned long bg, first_data_block, first_meta_bg;
542 int has_super = 0;
543
544 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
545 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
546
547 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
548 nr < first_meta_bg)
549 return (logic_sb_block + nr + 1);
550 bg = sbi->s_desc_per_block * nr;
551 if (ext2_bg_has_super(sb, bg))
552 has_super = 1;
553 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
554}
555
556static int ext2_fill_super(struct super_block *sb, void *data, int silent)
557{
558 struct buffer_head * bh;
559 struct ext2_sb_info * sbi;
560 struct ext2_super_block * es;
561 struct inode *root;
562 unsigned long block;
563 unsigned long sb_block = get_sb_block(&data);
564 unsigned long logic_sb_block;
565 unsigned long offset = 0;
566 unsigned long def_mount_opts;
567 int blocksize = BLOCK_SIZE;
568 int db_count;
569 int i, j;
570 __le32 features;
571
572 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
573 if (!sbi)
574 return -ENOMEM;
575 sb->s_fs_info = sbi;
576 memset(sbi, 0, sizeof(*sbi));
577
578 /*
579 * See what the current blocksize for the device is, and
580 * use that as the blocksize. Otherwise (or if the blocksize
581 * is smaller than the default) use the default.
582 * This is important for devices that have a hardware
583 * sectorsize that is larger than the default.
584 */
585 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
586 if (!blocksize) {
587 printk ("EXT2-fs: unable to set blocksize\n");
588 goto failed_sbi;
589 }
590
591 /*
592 * If the superblock doesn't start on a hardware sector boundary,
593 * calculate the offset.
594 */
595 if (blocksize != BLOCK_SIZE) {
596 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
597 offset = (sb_block*BLOCK_SIZE) % blocksize;
598 } else {
599 logic_sb_block = sb_block;
600 }
601
602 if (!(bh = sb_bread(sb, logic_sb_block))) {
603 printk ("EXT2-fs: unable to read superblock\n");
604 goto failed_sbi;
605 }
606 /*
607 * Note: s_es must be initialized as soon as possible because
608 * some ext2 macro-instructions depend on its value
609 */
610 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
611 sbi->s_es = es;
612 sb->s_magic = le16_to_cpu(es->s_magic);
613
614 if (sb->s_magic != EXT2_SUPER_MAGIC)
615 goto cantfind_ext2;
616
617 /* Set defaults before we parse the mount options */
618 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
619 if (def_mount_opts & EXT2_DEFM_DEBUG)
620 set_opt(sbi->s_mount_opt, DEBUG);
621 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
622 set_opt(sbi->s_mount_opt, GRPID);
623 if (def_mount_opts & EXT2_DEFM_UID16)
624 set_opt(sbi->s_mount_opt, NO_UID32);
625 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
626 set_opt(sbi->s_mount_opt, XATTR_USER);
627 if (def_mount_opts & EXT2_DEFM_ACL)
628 set_opt(sbi->s_mount_opt, POSIX_ACL);
629
630 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
631 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
632 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
633 set_opt(sbi->s_mount_opt, ERRORS_RO);
634
635 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
636 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
637
638 if (!parse_options ((char *) data, sbi))
639 goto failed_mount;
640
641 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
642 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
643 MS_POSIXACL : 0);
644
645 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
646 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
647 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
648 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
649 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
650 "running e2fsck is recommended\n");
651 /*
652 * Check feature flags regardless of the revision level, since we
653 * previously didn't change the revision level when setting the flags,
654 * so there is a chance incompat flags are set on a rev 0 filesystem.
655 */
656 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
657 if (features) {
658 printk("EXT2-fs: %s: couldn't mount because of "
659 "unsupported optional features (%x).\n",
660 sb->s_id, le32_to_cpu(features));
661 goto failed_mount;
662 }
663 if (!(sb->s_flags & MS_RDONLY) &&
664 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
665 printk("EXT2-fs: %s: couldn't mount RDWR because of "
666 "unsupported optional features (%x).\n",
667 sb->s_id, le32_to_cpu(features));
668 goto failed_mount;
669 }
670
671 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
672
673 /* If the blocksize doesn't match, re-read the thing.. */
674 if (sb->s_blocksize != blocksize) {
675 brelse(bh);
676
677 if (!sb_set_blocksize(sb, blocksize)) {
678 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
679 goto failed_sbi;
680 }
681
682 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
683 offset = (sb_block*BLOCK_SIZE) % blocksize;
684 bh = sb_bread(sb, logic_sb_block);
685 if(!bh) {
686 printk("EXT2-fs: Couldn't read superblock on "
687 "2nd try.\n");
688 goto failed_sbi;
689 }
690 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
691 sbi->s_es = es;
692 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
693 printk ("EXT2-fs: Magic mismatch, very weird !\n");
694 goto failed_mount;
695 }
696 }
697
698 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
699
700 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
701 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
702 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
703 } else {
704 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
705 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
706 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
707 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
708 (sbi->s_inode_size > blocksize)) {
709 printk ("EXT2-fs: unsupported inode size: %d\n",
710 sbi->s_inode_size);
711 goto failed_mount;
712 }
713 }
714
715 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
716 le32_to_cpu(es->s_log_frag_size);
717 if (sbi->s_frag_size == 0)
718 goto cantfind_ext2;
719 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
720
721 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
722 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
723 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
724
725 if (EXT2_INODE_SIZE(sb) == 0)
726 goto cantfind_ext2;
727 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
728 if (sbi->s_inodes_per_block == 0)
729 goto cantfind_ext2;
730 sbi->s_itb_per_group = sbi->s_inodes_per_group /
731 sbi->s_inodes_per_block;
732 sbi->s_desc_per_block = sb->s_blocksize /
733 sizeof (struct ext2_group_desc);
734 sbi->s_sbh = bh;
735 sbi->s_mount_state = le16_to_cpu(es->s_state);
736 sbi->s_addr_per_block_bits =
737 log2 (EXT2_ADDR_PER_BLOCK(sb));
738 sbi->s_desc_per_block_bits =
739 log2 (EXT2_DESC_PER_BLOCK(sb));
740
741 if (sb->s_magic != EXT2_SUPER_MAGIC)
742 goto cantfind_ext2;
743
744 if (sb->s_blocksize != bh->b_size) {
745 if (!silent)
746 printk ("VFS: Unsupported blocksize on dev "
747 "%s.\n", sb->s_id);
748 goto failed_mount;
749 }
750
751 if (sb->s_blocksize != sbi->s_frag_size) {
752 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
753 sbi->s_frag_size, sb->s_blocksize);
754 goto failed_mount;
755 }
756
757 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
758 printk ("EXT2-fs: #blocks per group too big: %lu\n",
759 sbi->s_blocks_per_group);
760 goto failed_mount;
761 }
762 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
763 printk ("EXT2-fs: #fragments per group too big: %lu\n",
764 sbi->s_frags_per_group);
765 goto failed_mount;
766 }
767 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
768 printk ("EXT2-fs: #inodes per group too big: %lu\n",
769 sbi->s_inodes_per_group);
770 goto failed_mount;
771 }
772
773 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
774 goto cantfind_ext2;
775 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
776 le32_to_cpu(es->s_first_data_block) +
777 EXT2_BLOCKS_PER_GROUP(sb) - 1) /
778 EXT2_BLOCKS_PER_GROUP(sb);
779 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
780 EXT2_DESC_PER_BLOCK(sb);
781 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
782 if (sbi->s_group_desc == NULL) {
783 printk ("EXT2-fs: not enough memory\n");
784 goto failed_mount;
785 }
786 percpu_counter_init(&sbi->s_freeblocks_counter);
787 percpu_counter_init(&sbi->s_freeinodes_counter);
788 percpu_counter_init(&sbi->s_dirs_counter);
789 bgl_lock_init(&sbi->s_blockgroup_lock);
790 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
791 GFP_KERNEL);
792 if (!sbi->s_debts) {
793 printk ("EXT2-fs: not enough memory\n");
794 goto failed_mount_group_desc;
795 }
796 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
797 for (i = 0; i < db_count; i++) {
798 block = descriptor_loc(sb, logic_sb_block, i);
799 sbi->s_group_desc[i] = sb_bread(sb, block);
800 if (!sbi->s_group_desc[i]) {
801 for (j = 0; j < i; j++)
802 brelse (sbi->s_group_desc[j]);
803 printk ("EXT2-fs: unable to read group descriptors\n");
804 goto failed_mount_group_desc;
805 }
806 }
807 if (!ext2_check_descriptors (sb)) {
808 printk ("EXT2-fs: group descriptors corrupted!\n");
809 db_count = i;
810 goto failed_mount2;
811 }
812 sbi->s_gdb_count = db_count;
813 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
814 spin_lock_init(&sbi->s_next_gen_lock);
815 /*
816 * set up enough so that it can read an inode
817 */
818 sb->s_op = &ext2_sops;
819 sb->s_export_op = &ext2_export_ops;
820 sb->s_xattr = ext2_xattr_handlers;
821 root = iget(sb, EXT2_ROOT_INO);
822 sb->s_root = d_alloc_root(root);
823 if (!sb->s_root) {
824 iput(root);
825 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
826 goto failed_mount2;
827 }
828 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
829 dput(sb->s_root);
830 sb->s_root = NULL;
831 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
832 goto failed_mount2;
833 }
834 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
835 ext2_warning(sb, __FUNCTION__,
836 "mounting ext3 filesystem as ext2\n");
837 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
838 percpu_counter_mod(&sbi->s_freeblocks_counter,
839 ext2_count_free_blocks(sb));
840 percpu_counter_mod(&sbi->s_freeinodes_counter,
841 ext2_count_free_inodes(sb));
842 percpu_counter_mod(&sbi->s_dirs_counter,
843 ext2_count_dirs(sb));
844 return 0;
845
846cantfind_ext2:
847 if (!silent)
848 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
849 sb->s_id);
850 goto failed_mount;
851
852failed_mount2:
853 for (i = 0; i < db_count; i++)
854 brelse(sbi->s_group_desc[i]);
855failed_mount_group_desc:
856 kfree(sbi->s_group_desc);
857 kfree(sbi->s_debts);
858failed_mount:
859 brelse(bh);
860failed_sbi:
861 sb->s_fs_info = NULL;
862 kfree(sbi);
863 return -EINVAL;
864}
865
866static void ext2_commit_super (struct super_block * sb,
867 struct ext2_super_block * es)
868{
869 es->s_wtime = cpu_to_le32(get_seconds());
870 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
871 sb->s_dirt = 0;
872}
873
874static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
875{
876 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
877 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
878 es->s_wtime = cpu_to_le32(get_seconds());
879 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
880 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
881 sb->s_dirt = 0;
882}
883
884/*
885 * In the second extended file system, it is not necessary to
886 * write the super block since we use a mapping of the
887 * disk super block in a buffer.
888 *
889 * However, this function is still used to set the fs valid
890 * flags to 0. We need to set this flag to 0 since the fs
891 * may have been checked while mounted and e2fsck may have
892 * set s_state to EXT2_VALID_FS after some corrections.
893 */
894
895void ext2_write_super (struct super_block * sb)
896{
897 struct ext2_super_block * es;
898 lock_kernel();
899 if (!(sb->s_flags & MS_RDONLY)) {
900 es = EXT2_SB(sb)->s_es;
901
902 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
903 ext2_debug ("setting valid to 0\n");
904 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
905 ~EXT2_VALID_FS);
906 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
907 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
908 es->s_mtime = cpu_to_le32(get_seconds());
909 ext2_sync_super(sb, es);
910 } else
911 ext2_commit_super (sb, es);
912 }
913 sb->s_dirt = 0;
914 unlock_kernel();
915}
916
917static int ext2_remount (struct super_block * sb, int * flags, char * data)
918{
919 struct ext2_sb_info * sbi = EXT2_SB(sb);
920 struct ext2_super_block * es;
921
922 /*
923 * Allow the "check" option to be passed as a remount option.
924 */
925 if (!parse_options (data, sbi))
926 return -EINVAL;
927
928 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
929 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
930
931 es = sbi->s_es;
932 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
933 return 0;
934 if (*flags & MS_RDONLY) {
935 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
936 !(sbi->s_mount_state & EXT2_VALID_FS))
937 return 0;
938 /*
939 * OK, we are remounting a valid rw partition rdonly, so set
940 * the rdonly flag and then mark the partition as valid again.
941 */
942 es->s_state = cpu_to_le16(sbi->s_mount_state);
943 es->s_mtime = cpu_to_le32(get_seconds());
944 } else {
945 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
946 ~EXT2_FEATURE_RO_COMPAT_SUPP);
947 if (ret) {
948 printk("EXT2-fs: %s: couldn't remount RDWR because of "
949 "unsupported optional features (%x).\n",
950 sb->s_id, le32_to_cpu(ret));
951 return -EROFS;
952 }
953 /*
954 * Mounting a RDONLY partition read-write, so reread and
955 * store the current valid flag. (It may have been changed
956 * by e2fsck since we originally mounted the partition.)
957 */
958 sbi->s_mount_state = le16_to_cpu(es->s_state);
959 if (!ext2_setup_super (sb, es, 0))
960 sb->s_flags &= ~MS_RDONLY;
961 }
962 ext2_sync_super(sb, es);
963 return 0;
964}
965
966static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
967{
968 struct ext2_sb_info *sbi = EXT2_SB(sb);
969 unsigned long overhead;
970 int i;
971
972 if (test_opt (sb, MINIX_DF))
973 overhead = 0;
974 else {
975 /*
976 * Compute the overhead (FS structures)
977 */
978
979 /*
980 * All of the blocks before first_data_block are
981 * overhead
982 */
983 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
984
985 /*
986 * Add the overhead attributed to the superblock and
987 * block group descriptors. If the sparse superblocks
988 * feature is turned on, then not all groups have this.
989 */
990 for (i = 0; i < sbi->s_groups_count; i++)
991 overhead += ext2_bg_has_super(sb, i) +
992 ext2_bg_num_gdb(sb, i);
993
994 /*
995 * Every block group has an inode bitmap, a block
996 * bitmap, and an inode table.
997 */
998 overhead += (sbi->s_groups_count *
999 (2 + sbi->s_itb_per_group));
1000 }
1001
1002 buf->f_type = EXT2_SUPER_MAGIC;
1003 buf->f_bsize = sb->s_blocksize;
1004 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1005 buf->f_bfree = ext2_count_free_blocks(sb);
1006 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1007 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1008 buf->f_bavail = 0;
1009 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1010 buf->f_ffree = ext2_count_free_inodes (sb);
1011 buf->f_namelen = EXT2_NAME_LEN;
1012 return 0;
1013}
1014
1015static struct super_block *ext2_get_sb(struct file_system_type *fs_type,
1016 int flags, const char *dev_name, void *data)
1017{
1018 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1019}
1020
1021#ifdef CONFIG_QUOTA
1022
1023/* Read data from quotafile - avoid pagecache and such because we cannot afford
1024 * acquiring the locks... As quota files are never truncated and quota code
1025 * itself serializes the operations (and noone else should touch the files)
1026 * we don't have to be afraid of races */
1027static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1028 size_t len, loff_t off)
1029{
1030 struct inode *inode = sb_dqopt(sb)->files[type];
1031 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1032 int err = 0;
1033 int offset = off & (sb->s_blocksize - 1);
1034 int tocopy;
1035 size_t toread;
1036 struct buffer_head tmp_bh;
1037 struct buffer_head *bh;
1038 loff_t i_size = i_size_read(inode);
1039
1040 if (off > i_size)
1041 return 0;
1042 if (off+len > i_size)
1043 len = i_size-off;
1044 toread = len;
1045 while (toread > 0) {
1046 tocopy = sb->s_blocksize - offset < toread ?
1047 sb->s_blocksize - offset : toread;
1048
1049 tmp_bh.b_state = 0;
1050 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1051 if (err)
1052 return err;
1053 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1054 memset(data, 0, tocopy);
1055 else {
1056 bh = sb_bread(sb, tmp_bh.b_blocknr);
1057 if (!bh)
1058 return -EIO;
1059 memcpy(data, bh->b_data+offset, tocopy);
1060 brelse(bh);
1061 }
1062 offset = 0;
1063 toread -= tocopy;
1064 data += tocopy;
1065 blk++;
1066 }
1067 return len;
1068}
1069
1070/* Write to quotafile */
1071static ssize_t ext2_quota_write(struct super_block *sb, int type,
1072 const char *data, size_t len, loff_t off)
1073{
1074 struct inode *inode = sb_dqopt(sb)->files[type];
1075 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1076 int err = 0;
1077 int offset = off & (sb->s_blocksize - 1);
1078 int tocopy;
1079 size_t towrite = len;
1080 struct buffer_head tmp_bh;
1081 struct buffer_head *bh;
1082
1083 down(&inode->i_sem);
1084 while (towrite > 0) {
1085 tocopy = sb->s_blocksize - offset < towrite ?
1086 sb->s_blocksize - offset : towrite;
1087
1088 tmp_bh.b_state = 0;
1089 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1090 if (err)
1091 goto out;
1092 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1093 bh = sb_bread(sb, tmp_bh.b_blocknr);
1094 else
1095 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1096 if (!bh) {
1097 err = -EIO;
1098 goto out;
1099 }
1100 lock_buffer(bh);
1101 memcpy(bh->b_data+offset, data, tocopy);
1102 flush_dcache_page(bh->b_page);
1103 set_buffer_uptodate(bh);
1104 mark_buffer_dirty(bh);
1105 unlock_buffer(bh);
1106 brelse(bh);
1107 offset = 0;
1108 towrite -= tocopy;
1109 data += tocopy;
1110 blk++;
1111 }
1112out:
1113 if (len == towrite)
1114 return err;
1115 if (inode->i_size < off+len-towrite)
1116 i_size_write(inode, off+len-towrite);
1117 inode->i_version++;
1118 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1119 mark_inode_dirty(inode);
1120 up(&inode->i_sem);
1121 return len - towrite;
1122}
1123
1124#endif
1125
1126static struct file_system_type ext2_fs_type = {
1127 .owner = THIS_MODULE,
1128 .name = "ext2",
1129 .get_sb = ext2_get_sb,
1130 .kill_sb = kill_block_super,
1131 .fs_flags = FS_REQUIRES_DEV,
1132};
1133
1134static int __init init_ext2_fs(void)
1135{
1136 int err = init_ext2_xattr();
1137 if (err)
1138 return err;
1139 err = init_inodecache();
1140 if (err)
1141 goto out1;
1142 err = register_filesystem(&ext2_fs_type);
1143 if (err)
1144 goto out;
1145 return 0;
1146out:
1147 destroy_inodecache();
1148out1:
1149 exit_ext2_xattr();
1150 return err;
1151}
1152
1153static void __exit exit_ext2_fs(void)
1154{
1155 unregister_filesystem(&ext2_fs_type);
1156 destroy_inodecache();
1157 exit_ext2_xattr();
1158}
1159
1160module_init(init_ext2_fs)
1161module_exit(exit_ext2_fs)
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-26 17:49:58 -0500