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[PATCH] xip: fs/mm: execute in place
[deliverable/linux.git] / fs / ext2 / super.c
CommitLineData
1da177e4
LT		 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
1da177e4
LT		 201}
202
1da177e4
LT		 203#ifdef CONFIG_QUOTA
204static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
205static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
206#endif
207
208static struct super_operations ext2_sops = {
209 .alloc_inode = ext2_alloc_inode,
210 .destroy_inode = ext2_destroy_inode,
211 .read_inode = ext2_read_inode,
212 .write_inode = ext2_write_inode,
e072c6f2 213 .put_inode = ext2_put_inode,
1da177e4
LT		 214 .delete_inode = ext2_delete_inode,
215 .put_super = ext2_put_super,
216 .write_super = ext2_write_super,
217 .statfs = ext2_statfs,
218 .remount_fs = ext2_remount,
219 .clear_inode = ext2_clear_inode,
220#ifdef CONFIG_QUOTA
221 .quota_read = ext2_quota_read,
222 .quota_write = ext2_quota_write,
223#endif
224};
225
226/* Yes, most of these are left as NULL!!
227 * A NULL value implies the default, which works with ext2-like file
228 * systems, but can be improved upon.
229 * Currently only get_parent is required.
230 */
231struct dentry *ext2_get_parent(struct dentry *child);
232static struct export_operations ext2_export_ops = {
233 .get_parent = ext2_get_parent,
234};
235
236static unsigned long get_sb_block(void **data)
237{
238 unsigned long sb_block;
239 char *options = (char *) *data;
240
241 if (!options || strncmp(options, "sb=", 3) != 0)
242 return 1; /* Default location */
243 options += 3;
244 sb_block = simple_strtoul(options, &options, 0);
245 if (*options && *options != ',') {
246 printk("EXT2-fs: Invalid sb specification: %s\n",
247 (char *) *data);
248 return 1;
249 }
250 if (*options == ',')
251 options++;
252 *data = (void *) options;
253 return sb_block;
254}
255
256enum {
257 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
258 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
259 Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh,
260 Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
261 Opt_ignore, Opt_err,
262};
263
264static match_table_t tokens = {
265 {Opt_bsd_df, "bsddf"},
266 {Opt_minix_df, "minixdf"},
267 {Opt_grpid, "grpid"},
268 {Opt_grpid, "bsdgroups"},
269 {Opt_nogrpid, "nogrpid"},
270 {Opt_nogrpid, "sysvgroups"},
271 {Opt_resgid, "resgid=%u"},
272 {Opt_resuid, "resuid=%u"},
273 {Opt_sb, "sb=%u"},
274 {Opt_err_cont, "errors=continue"},
275 {Opt_err_panic, "errors=panic"},
276 {Opt_err_ro, "errors=remount-ro"},
277 {Opt_nouid32, "nouid32"},
278 {Opt_nocheck, "check=none"},
279 {Opt_nocheck, "nocheck"},
280 {Opt_check, "check"},
281 {Opt_debug, "debug"},
282 {Opt_oldalloc, "oldalloc"},
283 {Opt_orlov, "orlov"},
284 {Opt_nobh, "nobh"},
285 {Opt_user_xattr, "user_xattr"},
286 {Opt_nouser_xattr, "nouser_xattr"},
287 {Opt_acl, "acl"},
288 {Opt_noacl, "noacl"},
289 {Opt_ignore, "grpquota"},
290 {Opt_ignore, "noquota"},
291 {Opt_ignore, "quota"},
292 {Opt_ignore, "usrquota"},
293 {Opt_err, NULL}
294};
295
296static int parse_options (char * options,
297 struct ext2_sb_info *sbi)
298{
299 char * p;
300 substring_t args[MAX_OPT_ARGS];
301 unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
302 int option;
303
304 if (!options)
305 return 1;
306
307 while ((p = strsep (&options, ",")) != NULL) {
308 int token;
309 if (!*p)
310 continue;
311
312 token = match_token(p, tokens, args);
313 switch (token) {
314 case Opt_bsd_df:
315 clear_opt (sbi->s_mount_opt, MINIX_DF);
316 break;
317 case Opt_minix_df:
318 set_opt (sbi->s_mount_opt, MINIX_DF);
319 break;
320 case Opt_grpid:
321 set_opt (sbi->s_mount_opt, GRPID);
322 break;
323 case Opt_nogrpid:
324 clear_opt (sbi->s_mount_opt, GRPID);
325 break;
326 case Opt_resuid:
327 if (match_int(&args[0], &option))
328 return 0;
329 sbi->s_resuid = option;
330 break;
331 case Opt_resgid:
332 if (match_int(&args[0], &option))
333 return 0;
334 sbi->s_resgid = option;
335 break;
336 case Opt_sb:
337 /* handled by get_sb_block() instead of here */
338 /* *sb_block = match_int(&args[0]); */
339 break;
340 case Opt_err_panic:
341 kind = EXT2_MOUNT_ERRORS_PANIC;
342 break;
343 case Opt_err_ro:
344 kind = EXT2_MOUNT_ERRORS_RO;
345 break;
346 case Opt_err_cont:
347 kind = EXT2_MOUNT_ERRORS_CONT;
348 break;
349 case Opt_nouid32:
350 set_opt (sbi->s_mount_opt, NO_UID32);
351 break;
352 case Opt_check:
353#ifdef CONFIG_EXT2_CHECK
354 set_opt (sbi->s_mount_opt, CHECK);
355#else
356 printk("EXT2 Check option not supported\n");
357#endif
358 break;
359 case Opt_nocheck:
360 clear_opt (sbi->s_mount_opt, CHECK);
361 break;
362 case Opt_debug:
363 set_opt (sbi->s_mount_opt, DEBUG);
364 break;
365 case Opt_oldalloc:
366 set_opt (sbi->s_mount_opt, OLDALLOC);
367 break;
368 case Opt_orlov:
369 clear_opt (sbi->s_mount_opt, OLDALLOC);
370 break;
371 case Opt_nobh:
372 set_opt (sbi->s_mount_opt, NOBH);
373 break;
374#ifdef CONFIG_EXT2_FS_XATTR
375 case Opt_user_xattr:
376 set_opt (sbi->s_mount_opt, XATTR_USER);
377 break;
378 case Opt_nouser_xattr:
379 clear_opt (sbi->s_mount_opt, XATTR_USER);
380 break;
381#else
382 case Opt_user_xattr:
383 case Opt_nouser_xattr:
384 printk("EXT2 (no)user_xattr options not supported\n");
385 break;
386#endif
387#ifdef CONFIG_EXT2_FS_POSIX_ACL
388 case Opt_acl:
389 set_opt(sbi->s_mount_opt, POSIX_ACL);
390 break;
391 case Opt_noacl:
392 clear_opt(sbi->s_mount_opt, POSIX_ACL);
393 break;
394#else
395 case Opt_acl:
396 case Opt_noacl:
397 printk("EXT2 (no)acl options not supported\n");
398 break;
399#endif
400 case Opt_ignore:
401 break;
402 default:
403 return 0;
404 }
405 }
406 sbi->s_mount_opt |= kind;
407 return 1;
408}
409
410static int ext2_setup_super (struct super_block * sb,
411 struct ext2_super_block * es,
412 int read_only)
413{
414 int res = 0;
415 struct ext2_sb_info *sbi = EXT2_SB(sb);
416
417 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
418 printk ("EXT2-fs warning: revision level too high, "
419 "forcing read-only mode\n");
420 res = MS_RDONLY;
421 }
422 if (read_only)
423 return res;
424 if (!(sbi->s_mount_state & EXT2_VALID_FS))
425 printk ("EXT2-fs warning: mounting unchecked fs, "
426 "running e2fsck is recommended\n");
427 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
428 printk ("EXT2-fs warning: mounting fs with errors, "
429 "running e2fsck is recommended\n");
430 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
431 le16_to_cpu(es->s_mnt_count) >=
432 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
433 printk ("EXT2-fs warning: maximal mount count reached, "
434 "running e2fsck is recommended\n");
435 else if (le32_to_cpu(es->s_checkinterval) &&
436 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
437 printk ("EXT2-fs warning: checktime reached, "
438 "running e2fsck is recommended\n");
439 if (!le16_to_cpu(es->s_max_mnt_count))
440 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
441 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
442 ext2_write_super(sb);
443 if (test_opt (sb, DEBUG))
444 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
445 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
446 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
447 sbi->s_frag_size,
448 sbi->s_groups_count,
449 EXT2_BLOCKS_PER_GROUP(sb),
450 EXT2_INODES_PER_GROUP(sb),
451 sbi->s_mount_opt);
452#ifdef CONFIG_EXT2_CHECK
453 if (test_opt (sb, CHECK)) {
454 ext2_check_blocks_bitmap (sb);
455 ext2_check_inodes_bitmap (sb);
456 }
457#endif
458 return res;
459}
460
461static int ext2_check_descriptors (struct super_block * sb)
462{
463 int i;
464 int desc_block = 0;
465 struct ext2_sb_info *sbi = EXT2_SB(sb);
466 unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
467 struct ext2_group_desc * gdp = NULL;
468
469 ext2_debug ("Checking group descriptors");
470
471 for (i = 0; i < sbi->s_groups_count; i++)
472 {
473 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
474 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
475 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
476 le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
477 {
478 ext2_error (sb, "ext2_check_descriptors",
479 "Block bitmap for group %d"
480 " not in group (block %lu)!",
481 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
482 return 0;
483 }
484 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
485 le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
486 {
487 ext2_error (sb, "ext2_check_descriptors",
488 "Inode bitmap for group %d"
489 " not in group (block %lu)!",
490 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
491 return 0;
492 }
493 if (le32_to_cpu(gdp->bg_inode_table) < block ||
494 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
495 block + EXT2_BLOCKS_PER_GROUP(sb))
496 {
497 ext2_error (sb, "ext2_check_descriptors",
498 "Inode table for group %d"
499 " not in group (block %lu)!",
500 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
501 return 0;
502 }
503 block += EXT2_BLOCKS_PER_GROUP(sb);
504 gdp++;
505 }
506 return 1;
507}
508
509#define log2(n) ffz(~(n))
510
511/*
512 * Maximal file size. There is a direct, and {,double-,triple-}indirect
513 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
514 * We need to be 1 filesystem block less than the 2^32 sector limit.
515 */
516static loff_t ext2_max_size(int bits)
517{
518 loff_t res = EXT2_NDIR_BLOCKS;
519 /* This constant is calculated to be the largest file size for a
520 * dense, 4k-blocksize file such that the total number of
521 * sectors in the file, including data and all indirect blocks,
522 * does not exceed 2^32. */
523 const loff_t upper_limit = 0x1ff7fffd000LL;
524
525 res += 1LL << (bits-2);
526 res += 1LL << (2*(bits-2));
527 res += 1LL << (3*(bits-2));
528 res <<= bits;
529 if (res > upper_limit)
530 res = upper_limit;
531 return res;
532}
533
534static unsigned long descriptor_loc(struct super_block *sb,
535 unsigned long logic_sb_block,
536 int nr)
537{
538 struct ext2_sb_info *sbi = EXT2_SB(sb);
539 unsigned long bg, first_data_block, first_meta_bg;
540 int has_super = 0;
541
542 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
543 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
544
545 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
546 nr < first_meta_bg)
547 return (logic_sb_block + nr + 1);
548 bg = sbi->s_desc_per_block * nr;
549 if (ext2_bg_has_super(sb, bg))
550 has_super = 1;
551 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
552}
553
554static int ext2_fill_super(struct super_block *sb, void *data, int silent)
555{
556 struct buffer_head * bh;
557 struct ext2_sb_info * sbi;
558 struct ext2_super_block * es;
559 struct inode *root;
560 unsigned long block;
561 unsigned long sb_block = get_sb_block(&data);
562 unsigned long logic_sb_block;
563 unsigned long offset = 0;
564 unsigned long def_mount_opts;
565 int blocksize = BLOCK_SIZE;
566 int db_count;
567 int i, j;
568 __le32 features;
569
570 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
571 if (!sbi)
572 return -ENOMEM;
573 sb->s_fs_info = sbi;
574 memset(sbi, 0, sizeof(*sbi));
575
576 /*
577 * See what the current blocksize for the device is, and
578 * use that as the blocksize. Otherwise (or if the blocksize
579 * is smaller than the default) use the default.
580 * This is important for devices that have a hardware
581 * sectorsize that is larger than the default.
582 */
583 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
584 if (!blocksize) {
585 printk ("EXT2-fs: unable to set blocksize\n");
586 goto failed_sbi;
587 }
588
589 /*
590 * If the superblock doesn't start on a hardware sector boundary,
591 * calculate the offset.
592 */
593 if (blocksize != BLOCK_SIZE) {
594 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
595 offset = (sb_block*BLOCK_SIZE) % blocksize;
596 } else {
597 logic_sb_block = sb_block;
598 }
599
600 if (!(bh = sb_bread(sb, logic_sb_block))) {
601 printk ("EXT2-fs: unable to read superblock\n");
602 goto failed_sbi;
603 }
604 /*
605 * Note: s_es must be initialized as soon as possible because
606 * some ext2 macro-instructions depend on its value
607 */
608 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
609 sbi->s_es = es;
610 sb->s_magic = le16_to_cpu(es->s_magic);
611
612 if (sb->s_magic != EXT2_SUPER_MAGIC)
613 goto cantfind_ext2;
614
615 /* Set defaults before we parse the mount options */
616 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
617 if (def_mount_opts & EXT2_DEFM_DEBUG)
618 set_opt(sbi->s_mount_opt, DEBUG);
619 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
620 set_opt(sbi->s_mount_opt, GRPID);
621 if (def_mount_opts & EXT2_DEFM_UID16)
622 set_opt(sbi->s_mount_opt, NO_UID32);
623 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
624 set_opt(sbi->s_mount_opt, XATTR_USER);
625 if (def_mount_opts & EXT2_DEFM_ACL)
626 set_opt(sbi->s_mount_opt, POSIX_ACL);
627
628 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
629 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
630 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
631 set_opt(sbi->s_mount_opt, ERRORS_RO);
632
633 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
634 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
635
636 if (!parse_options ((char *) data, sbi))
637 goto failed_mount;
638
639 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
640 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
641 MS_POSIXACL : 0);
642
643 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
644 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
645 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
646 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
647 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
648 "running e2fsck is recommended\n");
649 /*
650 * Check feature flags regardless of the revision level, since we
651 * previously didn't change the revision level when setting the flags,
652 * so there is a chance incompat flags are set on a rev 0 filesystem.
653 */
654 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
655 if (features) {
656 printk("EXT2-fs: %s: couldn't mount because of "
657 "unsupported optional features (%x).\n",
658 sb->s_id, le32_to_cpu(features));
659 goto failed_mount;
660 }
661 if (!(sb->s_flags & MS_RDONLY) &&
662 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
663 printk("EXT2-fs: %s: couldn't mount RDWR because of "
664 "unsupported optional features (%x).\n",
665 sb->s_id, le32_to_cpu(features));
666 goto failed_mount;
667 }
668
669 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
670
671 /* If the blocksize doesn't match, re-read the thing.. */
672 if (sb->s_blocksize != blocksize) {
673 brelse(bh);
674
675 if (!sb_set_blocksize(sb, blocksize)) {
676 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
677 goto failed_sbi;
678 }
679
680 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
681 offset = (sb_block*BLOCK_SIZE) % blocksize;
682 bh = sb_bread(sb, logic_sb_block);
683 if(!bh) {
684 printk("EXT2-fs: Couldn't read superblock on "
685 "2nd try.\n");
686 goto failed_sbi;
687 }
688 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
689 sbi->s_es = es;
690 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
691 printk ("EXT2-fs: Magic mismatch, very weird !\n");
692 goto failed_mount;
693 }
694 }
695
696 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
697
698 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
699 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
700 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
701 } else {
702 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
703 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
704 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
705 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
706 (sbi->s_inode_size > blocksize)) {
707 printk ("EXT2-fs: unsupported inode size: %d\n",
708 sbi->s_inode_size);
709 goto failed_mount;
710 }
711 }
712
713 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
714 le32_to_cpu(es->s_log_frag_size);
715 if (sbi->s_frag_size == 0)
716 goto cantfind_ext2;
717 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
718
719 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
720 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
721 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
722
723 if (EXT2_INODE_SIZE(sb) == 0)
724 goto cantfind_ext2;
725 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
726 if (sbi->s_inodes_per_block == 0)
727 goto cantfind_ext2;
728 sbi->s_itb_per_group = sbi->s_inodes_per_group /
729 sbi->s_inodes_per_block;
730 sbi->s_desc_per_block = sb->s_blocksize /
731 sizeof (struct ext2_group_desc);
732 sbi->s_sbh = bh;
733 sbi->s_mount_state = le16_to_cpu(es->s_state);
734 sbi->s_addr_per_block_bits =
735 log2 (EXT2_ADDR_PER_BLOCK(sb));
736 sbi->s_desc_per_block_bits =
737 log2 (EXT2_DESC_PER_BLOCK(sb));
738
739 if (sb->s_magic != EXT2_SUPER_MAGIC)
740 goto cantfind_ext2;
741
742 if (sb->s_blocksize != bh->b_size) {
743 if (!silent)
744 printk ("VFS: Unsupported blocksize on dev "
745 "%s.\n", sb->s_id);
746 goto failed_mount;
747 }
748
749 if (sb->s_blocksize != sbi->s_frag_size) {
750 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
751 sbi->s_frag_size, sb->s_blocksize);
752 goto failed_mount;
753 }
754
755 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
756 printk ("EXT2-fs: #blocks per group too big: %lu\n",
757 sbi->s_blocks_per_group);
758 goto failed_mount;
759 }
760 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
761 printk ("EXT2-fs: #fragments per group too big: %lu\n",
762 sbi->s_frags_per_group);
763 goto failed_mount;
764 }
765 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
766 printk ("EXT2-fs: #inodes per group too big: %lu\n",
767 sbi->s_inodes_per_group);
768 goto failed_mount;
769 }
770
771 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
772 goto cantfind_ext2;
773 sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
774 le32_to_cpu(es->s_first_data_block) +
775 EXT2_BLOCKS_PER_GROUP(sb) - 1) /
776 EXT2_BLOCKS_PER_GROUP(sb);
777 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
778 EXT2_DESC_PER_BLOCK(sb);
779 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
780 if (sbi->s_group_desc == NULL) {
781 printk ("EXT2-fs: not enough memory\n");
782 goto failed_mount;
783 }
784 percpu_counter_init(&sbi->s_freeblocks_counter);
785 percpu_counter_init(&sbi->s_freeinodes_counter);
786 percpu_counter_init(&sbi->s_dirs_counter);
787 bgl_lock_init(&sbi->s_blockgroup_lock);
788 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
789 GFP_KERNEL);
790 if (!sbi->s_debts) {
791 printk ("EXT2-fs: not enough memory\n");
792 goto failed_mount_group_desc;
793 }
794 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
795 for (i = 0; i < db_count; i++) {
796 block = descriptor_loc(sb, logic_sb_block, i);
797 sbi->s_group_desc[i] = sb_bread(sb, block);
798 if (!sbi->s_group_desc[i]) {
799 for (j = 0; j < i; j++)
800 brelse (sbi->s_group_desc[j]);
801 printk ("EXT2-fs: unable to read group descriptors\n");
802 goto failed_mount_group_desc;
803 }
804 }
805 if (!ext2_check_descriptors (sb)) {
806 printk ("EXT2-fs: group descriptors corrupted!\n");
807 db_count = i;
808 goto failed_mount2;
809 }
810 sbi->s_gdb_count = db_count;
811 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
812 spin_lock_init(&sbi->s_next_gen_lock);
813 /*
814 * set up enough so that it can read an inode
815 */
816 sb->s_op = &ext2_sops;
817 sb->s_export_op = &ext2_export_ops;
818 sb->s_xattr = ext2_xattr_handlers;
819 root = iget(sb, EXT2_ROOT_INO);
820 sb->s_root = d_alloc_root(root);
821 if (!sb->s_root) {
822 iput(root);
823 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
824 goto failed_mount2;
825 }
826 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
827 dput(sb->s_root);
828 sb->s_root = NULL;
829 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
830 goto failed_mount2;
831 }
832 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
833 ext2_warning(sb, __FUNCTION__,
834 "mounting ext3 filesystem as ext2\n");
835 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
836 percpu_counter_mod(&sbi->s_freeblocks_counter,
837 ext2_count_free_blocks(sb));
838 percpu_counter_mod(&sbi->s_freeinodes_counter,
839 ext2_count_free_inodes(sb));
840 percpu_counter_mod(&sbi->s_dirs_counter,
841 ext2_count_dirs(sb));
842 return 0;
843
844cantfind_ext2:
845 if (!silent)
846 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
847 sb->s_id);
848 goto failed_mount;
849
850failed_mount2:
851 for (i = 0; i < db_count; i++)
852 brelse(sbi->s_group_desc[i]);
853failed_mount_group_desc:
854 kfree(sbi->s_group_desc);
855 kfree(sbi->s_debts);
856failed_mount:
857 brelse(bh);
858failed_sbi:
859 sb->s_fs_info = NULL;
860 kfree(sbi);
861 return -EINVAL;
862}
863
864static void ext2_commit_super (struct super_block * sb,
865 struct ext2_super_block * es)
866{
867 es->s_wtime = cpu_to_le32(get_seconds());
868 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
869 sb->s_dirt = 0;
870}
871
872static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
873{
874 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
875 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
876 es->s_wtime = cpu_to_le32(get_seconds());
877 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
878 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
879 sb->s_dirt = 0;
880}
881
882/*
883 * In the second extended file system, it is not necessary to
884 * write the super block since we use a mapping of the
885 * disk super block in a buffer.
886 *
887 * However, this function is still used to set the fs valid
888 * flags to 0. We need to set this flag to 0 since the fs
889 * may have been checked while mounted and e2fsck may have
890 * set s_state to EXT2_VALID_FS after some corrections.
891 */
892
893void ext2_write_super (struct super_block * sb)
894{
895 struct ext2_super_block * es;
896 lock_kernel();
897 if (!(sb->s_flags & MS_RDONLY)) {
898 es = EXT2_SB(sb)->s_es;
899
900 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
901 ext2_debug ("setting valid to 0\n");
902 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
903 ~EXT2_VALID_FS);
904 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
905 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
906 es->s_mtime = cpu_to_le32(get_seconds());
907 ext2_sync_super(sb, es);
908 } else
909 ext2_commit_super (sb, es);
910 }
911 sb->s_dirt = 0;
912 unlock_kernel();
913}
914
915static int ext2_remount (struct super_block * sb, int * flags, char * data)
916{
917 struct ext2_sb_info * sbi = EXT2_SB(sb);
918 struct ext2_super_block * es;
919
920 /*
921 * Allow the "check" option to be passed as a remount option.
922 */
923 if (!parse_options (data, sbi))
924 return -EINVAL;
925
926 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
927 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
928
929 es = sbi->s_es;
930 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
931 return 0;
932 if (*flags & MS_RDONLY) {
933 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
934 !(sbi->s_mount_state & EXT2_VALID_FS))
935 return 0;
936 /*
937 * OK, we are remounting a valid rw partition rdonly, so set
938 * the rdonly flag and then mark the partition as valid again.
939 */
940 es->s_state = cpu_to_le16(sbi->s_mount_state);
941 es->s_mtime = cpu_to_le32(get_seconds());
942 } else {
943 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
944 ~EXT2_FEATURE_RO_COMPAT_SUPP);
945 if (ret) {
946 printk("EXT2-fs: %s: couldn't remount RDWR because of "
947 "unsupported optional features (%x).\n",
948 sb->s_id, le32_to_cpu(ret));
949 return -EROFS;
950 }
951 /*
952 * Mounting a RDONLY partition read-write, so reread and
953 * store the current valid flag. (It may have been changed
954 * by e2fsck since we originally mounted the partition.)
955 */
956 sbi->s_mount_state = le16_to_cpu(es->s_state);
957 if (!ext2_setup_super (sb, es, 0))
958 sb->s_flags &= ~MS_RDONLY;
959 }
960 ext2_sync_super(sb, es);
961 return 0;
962}
963
964static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
965{
966 struct ext2_sb_info *sbi = EXT2_SB(sb);
967 unsigned long overhead;
968 int i;
969
970 if (test_opt (sb, MINIX_DF))
971 overhead = 0;
972 else {
973 /*
974 * Compute the overhead (FS structures)
975 */
976
977 /*
978 * All of the blocks before first_data_block are
979 * overhead
980 */
981 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
982
983 /*
984 * Add the overhead attributed to the superblock and
985 * block group descriptors. If the sparse superblocks
986 * feature is turned on, then not all groups have this.
987 */
988 for (i = 0; i < sbi->s_groups_count; i++)
989 overhead += ext2_bg_has_super(sb, i) +
990 ext2_bg_num_gdb(sb, i);
991
992 /*
993 * Every block group has an inode bitmap, a block
994 * bitmap, and an inode table.
995 */
996 overhead += (sbi->s_groups_count *
997 (2 + sbi->s_itb_per_group));
998 }
999
1000 buf->f_type = EXT2_SUPER_MAGIC;
1001 buf->f_bsize = sb->s_blocksize;
1002 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1003 buf->f_bfree = ext2_count_free_blocks(sb);
1004 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1005 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1006 buf->f_bavail = 0;
1007 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1008 buf->f_ffree = ext2_count_free_inodes (sb);
1009 buf->f_namelen = EXT2_NAME_LEN;
1010 return 0;
1011}
1012
1013static struct super_block *ext2_get_sb(struct file_system_type *fs_type,
1014 int flags, const char *dev_name, void *data)
1015{
1016 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1017}
1018
1019#ifdef CONFIG_QUOTA
1020
1021/* Read data from quotafile - avoid pagecache and such because we cannot afford
1022 * acquiring the locks... As quota files are never truncated and quota code
1023 * itself serializes the operations (and noone else should touch the files)
1024 * we don't have to be afraid of races */
1025static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1026 size_t len, loff_t off)
1027{
1028 struct inode *inode = sb_dqopt(sb)->files[type];
1029 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1030 int err = 0;
1031 int offset = off & (sb->s_blocksize - 1);
1032 int tocopy;
1033 size_t toread;
1034 struct buffer_head tmp_bh;
1035 struct buffer_head *bh;
1036 loff_t i_size = i_size_read(inode);
1037
1038 if (off > i_size)
1039 return 0;
1040 if (off+len > i_size)
1041 len = i_size-off;
1042 toread = len;
1043 while (toread > 0) {
1044 tocopy = sb->s_blocksize - offset < toread ?
1045 sb->s_blocksize - offset : toread;
1046
1047 tmp_bh.b_state = 0;
1048 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1049 if (err)
1050 return err;
1051 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1052 memset(data, 0, tocopy);
1053 else {
1054 bh = sb_bread(sb, tmp_bh.b_blocknr);
1055 if (!bh)
1056 return -EIO;
1057 memcpy(data, bh->b_data+offset, tocopy);
1058 brelse(bh);
1059 }
1060 offset = 0;
1061 toread -= tocopy;
1062 data += tocopy;
1063 blk++;
1064 }
1065 return len;
1066}
1067
1068/* Write to quotafile */
1069static ssize_t ext2_quota_write(struct super_block *sb, int type,
1070 const char *data, size_t len, loff_t off)
1071{
1072 struct inode *inode = sb_dqopt(sb)->files[type];
1073 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1074 int err = 0;
1075 int offset = off & (sb->s_blocksize - 1);
1076 int tocopy;
1077 size_t towrite = len;
1078 struct buffer_head tmp_bh;
1079 struct buffer_head *bh;
1080
1081 down(&inode->i_sem);
1082 while (towrite > 0) {
1083 tocopy = sb->s_blocksize - offset < towrite ?
1084 sb->s_blocksize - offset : towrite;
1085
1086 tmp_bh.b_state = 0;
1087 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1088 if (err)
1089 goto out;
1090 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1091 bh = sb_bread(sb, tmp_bh.b_blocknr);
1092 else
1093 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1094 if (!bh) {
1095 err = -EIO;
1096 goto out;
1097 }
1098 lock_buffer(bh);
1099 memcpy(bh->b_data+offset, data, tocopy);
1100 flush_dcache_page(bh->b_page);
1101 set_buffer_uptodate(bh);
1102 mark_buffer_dirty(bh);
1103 unlock_buffer(bh);
1104 brelse(bh);
1105 offset = 0;
1106 towrite -= tocopy;
1107 data += tocopy;
1108 blk++;
1109 }
1110out:
1111 if (len == towrite)
1112 return err;
1113 if (inode->i_size < off+len-towrite)
1114 i_size_write(inode, off+len-towrite);
1115 inode->i_version++;
1116 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1117 mark_inode_dirty(inode);
1118 up(&inode->i_sem);
1119 return len - towrite;
1120}
1121
1122#endif
1123
1124static struct file_system_type ext2_fs_type = {
1125 .owner = THIS_MODULE,
1126 .name = "ext2",
1127 .get_sb = ext2_get_sb,
1128 .kill_sb = kill_block_super,
1129 .fs_flags = FS_REQUIRES_DEV,
1130};
1131
1132static int __init init_ext2_fs(void)
1133{
1134 int err = init_ext2_xattr();
1135 if (err)
1136 return err;
1137 err = init_inodecache();
1138 if (err)
1139 goto out1;
1140 err = register_filesystem(&ext2_fs_type);
1141 if (err)
1142 goto out;
1143 return 0;
1144out:
1145 destroy_inodecache();
1146out1:
1147 exit_ext2_xattr();
1148 return err;
1149}
1150
1151static void __exit exit_ext2_fs(void)
1152{
1153 unregister_filesystem(&ext2_fs_type);
1154 destroy_inodecache();
1155 exit_ext2_xattr();
1156}
1157
1158module_init(init_ext2_fs)
1159module_exit(exit_ext2_fs)
Linux kernel - Deliverables
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