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[net-next-2.6.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
1da177e4
LT		 19#include <linux/module.h>
20#include <linux/string.h>
8fc2751b 21#include <linux/fs.h>
1da177e4
LT		 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>
8fc2751b
MB		 30#include <linux/seq_file.h>
31#include <linux/mount.h>
1da177e4
LT		 32#include <asm/uaccess.h>
33#include "ext2.h"
34#include "xattr.h"
35#include "acl.h"
6d79125b 36#include "xip.h"
1da177e4
LT		 37
38static void ext2_sync_super(struct super_block *sb,
39 struct ext2_super_block *es);
40static int ext2_remount (struct super_block * sb, int * flags, char * data);
726c3342 41static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
1da177e4
LT		 42
43void ext2_error (struct super_block * sb, const char * function,
44 const char * fmt, ...)
45{
46 va_list args;
47 struct ext2_sb_info *sbi = EXT2_SB(sb);
48 struct ext2_super_block *es = sbi->s_es;
49
50 if (!(sb->s_flags & MS_RDONLY)) {
51 sbi->s_mount_state |= EXT2_ERROR_FS;
52 es->s_state =
53 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
54 ext2_sync_super(sb, es);
55 }
56
57 va_start(args, fmt);
58 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
59 vprintk(fmt, args);
60 printk("\n");
61 va_end(args);
62
63 if (test_opt(sb, ERRORS_PANIC))
64 panic("EXT2-fs panic from previous error\n");
65 if (test_opt(sb, ERRORS_RO)) {
66 printk("Remounting filesystem read-only\n");
67 sb->s_flags |= MS_RDONLY;
68 }
69}
70
71void ext2_warning (struct super_block * sb, const char * function,
72 const char * fmt, ...)
73{
74 va_list args;
75
76 va_start(args, fmt);
77 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
78 sb->s_id, function);
79 vprintk(fmt, args);
80 printk("\n");
81 va_end(args);
82}
83
84void ext2_update_dynamic_rev(struct super_block *sb)
85{
86 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
87
88 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
89 return;
90
91 ext2_warning(sb, __FUNCTION__,
92 "updating to rev %d because of new feature flag, "
93 "running e2fsck is recommended",
94 EXT2_DYNAMIC_REV);
95
96 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
97 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
98 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
99 /* leave es->s_feature_*compat flags alone */
100 /* es->s_uuid will be set by e2fsck if empty */
101
102 /*
103 * The rest of the superblock fields should be zero, and if not it
104 * means they are likely already in use, so leave them alone. We
105 * can leave it up to e2fsck to clean up any inconsistencies there.
106 */
107}
108
109static void ext2_put_super (struct super_block * sb)
110{
111 int db_count;
112 int i;
113 struct ext2_sb_info *sbi = EXT2_SB(sb);
114
115 ext2_xattr_put_super(sb);
116 if (!(sb->s_flags & MS_RDONLY)) {
117 struct ext2_super_block *es = sbi->s_es;
118
119 es->s_state = cpu_to_le16(sbi->s_mount_state);
120 ext2_sync_super(sb, es);
121 }
122 db_count = sbi->s_gdb_count;
123 for (i = 0; i < db_count; i++)
124 if (sbi->s_group_desc[i])
125 brelse (sbi->s_group_desc[i]);
126 kfree(sbi->s_group_desc);
127 kfree(sbi->s_debts);
128 percpu_counter_destroy(&sbi->s_freeblocks_counter);
129 percpu_counter_destroy(&sbi->s_freeinodes_counter);
130 percpu_counter_destroy(&sbi->s_dirs_counter);
131 brelse (sbi->s_sbh);
132 sb->s_fs_info = NULL;
133 kfree(sbi);
134
135 return;
136}
137
138static kmem_cache_t * ext2_inode_cachep;
139
140static struct inode *ext2_alloc_inode(struct super_block *sb)
141{
142 struct ext2_inode_info *ei;
e94b1766 143 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
1da177e4
LT		 144 if (!ei)
145 return NULL;
146#ifdef CONFIG_EXT2_FS_POSIX_ACL
147 ei->i_acl = EXT2_ACL_NOT_CACHED;
148 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
149#endif
150 ei->vfs_inode.i_version = 1;
151 return &ei->vfs_inode;
152}
153
154static void ext2_destroy_inode(struct inode *inode)
155{
156 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
157}
158
159static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
160{
161 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
162
163 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
164 SLAB_CTOR_CONSTRUCTOR) {
165 rwlock_init(&ei->i_meta_lock);
166#ifdef CONFIG_EXT2_FS_XATTR
167 init_rwsem(&ei->xattr_sem);
168#endif
169 inode_init_once(&ei->vfs_inode);
170 }
171}
172
173static int init_inodecache(void)
174{
175 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
176 sizeof(struct ext2_inode_info),
fffb60f9
PJ		 177 0, (SLAB_RECLAIM_ACCOUNT|
178 SLAB_MEM_SPREAD),
1da177e4
LT		 179 init_once, NULL);
180 if (ext2_inode_cachep == NULL)
181 return -ENOMEM;
182 return 0;
183}
184
185static void destroy_inodecache(void)
186{
1a1d92c1 187 kmem_cache_destroy(ext2_inode_cachep);
1da177e4
LT		 188}
189
190static void ext2_clear_inode(struct inode *inode)
191{
192#ifdef CONFIG_EXT2_FS_POSIX_ACL
193 struct ext2_inode_info *ei = EXT2_I(inode);
194
195 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
196 posix_acl_release(ei->i_acl);
197 ei->i_acl = EXT2_ACL_NOT_CACHED;
198 }
199 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
200 posix_acl_release(ei->i_default_acl);
201 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
202 }
203#endif
1da177e4
LT		 204}
205
8fc2751b
MB		 206static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
207{
208 struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
209
210 if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
211 seq_puts(seq, ",grpid");
8fc2751b
MB		 212
213#if defined(CONFIG_QUOTA)
214 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
215 seq_puts(seq, ",usrquota");
216
217 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
218 seq_puts(seq, ",grpquota");
219#endif
220
83541796
CO		 221#if defined(CONFIG_EXT2_FS_XIP)
222 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
223 seq_puts(seq, ",xip");
224#endif
225
8fc2751b
MB		 226 return 0;
227}
228
1da177e4
LT		 229#ifdef CONFIG_QUOTA
230static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
231static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
232#endif
233
234static struct super_operations ext2_sops = {
235 .alloc_inode = ext2_alloc_inode,
236 .destroy_inode = ext2_destroy_inode,
237 .read_inode = ext2_read_inode,
238 .write_inode = ext2_write_inode,
e072c6f2 239 .put_inode = ext2_put_inode,
1da177e4
LT		 240 .delete_inode = ext2_delete_inode,
241 .put_super = ext2_put_super,
242 .write_super = ext2_write_super,
243 .statfs = ext2_statfs,
244 .remount_fs = ext2_remount,
245 .clear_inode = ext2_clear_inode,
8fc2751b 246 .show_options = ext2_show_options,
1da177e4
LT		 247#ifdef CONFIG_QUOTA
248 .quota_read = ext2_quota_read,
249 .quota_write = ext2_quota_write,
250#endif
251};
252
ecaff756
N		 253static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
254{
255 __u32 *objp = vobjp;
256 unsigned long ino = objp[0];
257 __u32 generation = objp[1];
258 struct inode *inode;
259 struct dentry *result;
260
261 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
262 return ERR_PTR(-ESTALE);
263 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
264 return ERR_PTR(-ESTALE);
265
266 /* iget isn't really right if the inode is currently unallocated!!
267 * ext2_read_inode currently does appropriate checks, but
268 * it might be "neater" to call ext2_get_inode first and check
269 * if the inode is valid.....
270 */
271 inode = iget(sb, ino);
272 if (inode == NULL)
273 return ERR_PTR(-ENOMEM);
274 if (is_bad_inode(inode) ||
275 (generation && inode->i_generation != generation)) {
276 /* we didn't find the right inode.. */
277 iput(inode);
278 return ERR_PTR(-ESTALE);
279 }
280 /* now to find a dentry.
281 * If possible, get a well-connected one
282 */
283 result = d_alloc_anon(inode);
284 if (!result) {
285 iput(inode);
286 return ERR_PTR(-ENOMEM);
287 }
288 return result;
289}
290
1da177e4
LT		 291/* Yes, most of these are left as NULL!!
292 * A NULL value implies the default, which works with ext2-like file
293 * systems, but can be improved upon.
294 * Currently only get_parent is required.
295 */
1da177e4
LT		 296static struct export_operations ext2_export_ops = {
297 .get_parent = ext2_get_parent,
ecaff756 298 .get_dentry = ext2_get_dentry,
1da177e4
LT		 299};
300
301static unsigned long get_sb_block(void **data)
302{
303 unsigned long sb_block;
304 char *options = (char *) *data;
305
306 if (!options || strncmp(options, "sb=", 3) != 0)
307 return 1; /* Default location */
308 options += 3;
309 sb_block = simple_strtoul(options, &options, 0);
310 if (*options && *options != ',') {
311 printk("EXT2-fs: Invalid sb specification: %s\n",
312 (char *) *data);
313 return 1;
314 }
315 if (*options == ',')
316 options++;
317 *data = (void *) options;
318 return sb_block;
319}
320
321enum {
322 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
8fc2751b 323 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
2860b733 324 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
8fc2751b
MB		 325 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
326 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
327 Opt_usrquota, Opt_grpquota
1da177e4
LT		 328};
329
330static match_table_t tokens = {
331 {Opt_bsd_df, "bsddf"},
332 {Opt_minix_df, "minixdf"},
333 {Opt_grpid, "grpid"},
334 {Opt_grpid, "bsdgroups"},
335 {Opt_nogrpid, "nogrpid"},
336 {Opt_nogrpid, "sysvgroups"},
337 {Opt_resgid, "resgid=%u"},
338 {Opt_resuid, "resuid=%u"},
339 {Opt_sb, "sb=%u"},
340 {Opt_err_cont, "errors=continue"},
341 {Opt_err_panic, "errors=panic"},
342 {Opt_err_ro, "errors=remount-ro"},
343 {Opt_nouid32, "nouid32"},
344 {Opt_nocheck, "check=none"},
345 {Opt_nocheck, "nocheck"},
1da177e4
LT		 346 {Opt_debug, "debug"},
347 {Opt_oldalloc, "oldalloc"},
348 {Opt_orlov, "orlov"},
349 {Opt_nobh, "nobh"},
350 {Opt_user_xattr, "user_xattr"},
351 {Opt_nouser_xattr, "nouser_xattr"},
352 {Opt_acl, "acl"},
353 {Opt_noacl, "noacl"},
6d79125b 354 {Opt_xip, "xip"},
8fc2751b 355 {Opt_grpquota, "grpquota"},
1da177e4 356 {Opt_ignore, "noquota"},
8fc2751b
MB		 357 {Opt_quota, "quota"},
358 {Opt_usrquota, "usrquota"},
1da177e4
LT		 359 {Opt_err, NULL}
360};
361
362static int parse_options (char * options,
363 struct ext2_sb_info *sbi)
364{
365 char * p;
366 substring_t args[MAX_OPT_ARGS];
1da177e4
LT		 367 int option;
368
369 if (!options)
370 return 1;
371
372 while ((p = strsep (&options, ",")) != NULL) {
373 int token;
374 if (!*p)
375 continue;
376
377 token = match_token(p, tokens, args);
378 switch (token) {
379 case Opt_bsd_df:
380 clear_opt (sbi->s_mount_opt, MINIX_DF);
381 break;
382 case Opt_minix_df:
383 set_opt (sbi->s_mount_opt, MINIX_DF);
384 break;
385 case Opt_grpid:
386 set_opt (sbi->s_mount_opt, GRPID);
387 break;
388 case Opt_nogrpid:
389 clear_opt (sbi->s_mount_opt, GRPID);
390 break;
391 case Opt_resuid:
392 if (match_int(&args[0], &option))
393 return 0;
394 sbi->s_resuid = option;
395 break;
396 case Opt_resgid:
397 if (match_int(&args[0], &option))
398 return 0;
399 sbi->s_resgid = option;
400 break;
401 case Opt_sb:
402 /* handled by get_sb_block() instead of here */
403 /* *sb_block = match_int(&args[0]); */
404 break;
405 case Opt_err_panic:
5a2b4062
VA		 406 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
407 clear_opt (sbi->s_mount_opt, ERRORS_RO);
408 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
1da177e4
LT		 409 break;
410 case Opt_err_ro:
5a2b4062
VA		 411 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
412 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
413 set_opt (sbi->s_mount_opt, ERRORS_RO);
1da177e4
LT		 414 break;
415 case Opt_err_cont:
5a2b4062
VA		 416 clear_opt (sbi->s_mount_opt, ERRORS_RO);
417 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
418 set_opt (sbi->s_mount_opt, ERRORS_CONT);
1da177e4
LT		 419 break;
420 case Opt_nouid32:
421 set_opt (sbi->s_mount_opt, NO_UID32);
422 break;
1da177e4
LT		 423 case Opt_nocheck:
424 clear_opt (sbi->s_mount_opt, CHECK);
425 break;
426 case Opt_debug:
427 set_opt (sbi->s_mount_opt, DEBUG);
428 break;
429 case Opt_oldalloc:
430 set_opt (sbi->s_mount_opt, OLDALLOC);
431 break;
432 case Opt_orlov:
433 clear_opt (sbi->s_mount_opt, OLDALLOC);
434 break;
435 case Opt_nobh:
436 set_opt (sbi->s_mount_opt, NOBH);
437 break;
438#ifdef CONFIG_EXT2_FS_XATTR
439 case Opt_user_xattr:
440 set_opt (sbi->s_mount_opt, XATTR_USER);
441 break;
442 case Opt_nouser_xattr:
443 clear_opt (sbi->s_mount_opt, XATTR_USER);
444 break;
445#else
446 case Opt_user_xattr:
447 case Opt_nouser_xattr:
448 printk("EXT2 (no)user_xattr options not supported\n");
449 break;
450#endif
451#ifdef CONFIG_EXT2_FS_POSIX_ACL
452 case Opt_acl:
453 set_opt(sbi->s_mount_opt, POSIX_ACL);
454 break;
455 case Opt_noacl:
456 clear_opt(sbi->s_mount_opt, POSIX_ACL);
457 break;
458#else
459 case Opt_acl:
460 case Opt_noacl:
461 printk("EXT2 (no)acl options not supported\n");
462 break;
463#endif
6d79125b
CO		 464 case Opt_xip:
465#ifdef CONFIG_EXT2_FS_XIP
466 set_opt (sbi->s_mount_opt, XIP);
467#else
468 printk("EXT2 xip option not supported\n");
469#endif
470 break;
8fc2751b
MB		 471
472#if defined(CONFIG_QUOTA)
473 case Opt_quota:
474 case Opt_usrquota:
475 set_opt(sbi->s_mount_opt, USRQUOTA);
476 break;
477
478 case Opt_grpquota:
479 set_opt(sbi->s_mount_opt, GRPQUOTA);
480 break;
481#else
482 case Opt_quota:
483 case Opt_usrquota:
484 case Opt_grpquota:
485 printk(KERN_ERR
486 "EXT2-fs: quota operations not supported.\n");
487
488 break;
489#endif
490
1da177e4
LT		 491 case Opt_ignore:
492 break;
493 default:
494 return 0;
495 }
496 }
1da177e4
LT		 497 return 1;
498}
499
500static int ext2_setup_super (struct super_block * sb,
501 struct ext2_super_block * es,
502 int read_only)
503{
504 int res = 0;
505 struct ext2_sb_info *sbi = EXT2_SB(sb);
506
507 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
508 printk ("EXT2-fs warning: revision level too high, "
509 "forcing read-only mode\n");
510 res = MS_RDONLY;
511 }
512 if (read_only)
513 return res;
514 if (!(sbi->s_mount_state & EXT2_VALID_FS))
515 printk ("EXT2-fs warning: mounting unchecked fs, "
516 "running e2fsck is recommended\n");
517 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
518 printk ("EXT2-fs warning: mounting fs with errors, "
519 "running e2fsck is recommended\n");
520 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
521 le16_to_cpu(es->s_mnt_count) >=
522 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
523 printk ("EXT2-fs warning: maximal mount count reached, "
524 "running e2fsck is recommended\n");
525 else if (le32_to_cpu(es->s_checkinterval) &&
526 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
527 printk ("EXT2-fs warning: checktime reached, "
528 "running e2fsck is recommended\n");
529 if (!le16_to_cpu(es->s_max_mnt_count))
530 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
531 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
532 ext2_write_super(sb);
533 if (test_opt (sb, DEBUG))
534 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
535 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
536 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
537 sbi->s_frag_size,
538 sbi->s_groups_count,
539 EXT2_BLOCKS_PER_GROUP(sb),
540 EXT2_INODES_PER_GROUP(sb),
541 sbi->s_mount_opt);
1da177e4
LT		 542 return res;
543}
544
545static int ext2_check_descriptors (struct super_block * sb)
546{
547 int i;
548 int desc_block = 0;
549 struct ext2_sb_info *sbi = EXT2_SB(sb);
41f04d85
ES		 550 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
551 unsigned long last_block;
1da177e4
LT		 552 struct ext2_group_desc * gdp = NULL;
553
554 ext2_debug ("Checking group descriptors");
555
556 for (i = 0; i < sbi->s_groups_count; i++)
557 {
41f04d85
ES		 558 if (i == sbi->s_groups_count - 1)
559 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
560 else
561 last_block = first_block +
562 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
563
1da177e4
LT		 564 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
565 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
41f04d85
ES		 566 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
567 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
1da177e4
LT		 568 {
569 ext2_error (sb, "ext2_check_descriptors",
570 "Block bitmap for group %d"
571 " not in group (block %lu)!",
572 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
573 return 0;
574 }
41f04d85
ES		 575 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
576 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
1da177e4
LT		 577 {
578 ext2_error (sb, "ext2_check_descriptors",
579 "Inode bitmap for group %d"
580 " not in group (block %lu)!",
581 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
582 return 0;
583 }
41f04d85
ES		 584 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
585 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
586 last_block)
1da177e4
LT		 587 {
588 ext2_error (sb, "ext2_check_descriptors",
589 "Inode table for group %d"
590 " not in group (block %lu)!",
591 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
592 return 0;
593 }
41f04d85 594 first_block += EXT2_BLOCKS_PER_GROUP(sb);
1da177e4
LT		 595 gdp++;
596 }
597 return 1;
598}
599
600#define log2(n) ffz(~(n))
601
602/*
603 * Maximal file size. There is a direct, and {,double-,triple-}indirect
604 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
605 * We need to be 1 filesystem block less than the 2^32 sector limit.
606 */
607static loff_t ext2_max_size(int bits)
608{
609 loff_t res = EXT2_NDIR_BLOCKS;
610 /* This constant is calculated to be the largest file size for a
611 * dense, 4k-blocksize file such that the total number of
612 * sectors in the file, including data and all indirect blocks,
613 * does not exceed 2^32. */
614 const loff_t upper_limit = 0x1ff7fffd000LL;
615
616 res += 1LL << (bits-2);
617 res += 1LL << (2*(bits-2));
618 res += 1LL << (3*(bits-2));
619 res <<= bits;
620 if (res > upper_limit)
621 res = upper_limit;
622 return res;
623}
624
625static unsigned long descriptor_loc(struct super_block *sb,
626 unsigned long logic_sb_block,
627 int nr)
628{
629 struct ext2_sb_info *sbi = EXT2_SB(sb);
630 unsigned long bg, first_data_block, first_meta_bg;
631 int has_super = 0;
632
633 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
634 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
635
636 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
637 nr < first_meta_bg)
638 return (logic_sb_block + nr + 1);
639 bg = sbi->s_desc_per_block * nr;
640 if (ext2_bg_has_super(sb, bg))
641 has_super = 1;
642 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
643}
644
645static int ext2_fill_super(struct super_block *sb, void *data, int silent)
646{
647 struct buffer_head * bh;
648 struct ext2_sb_info * sbi;
649 struct ext2_super_block * es;
650 struct inode *root;
651 unsigned long block;
652 unsigned long sb_block = get_sb_block(&data);
653 unsigned long logic_sb_block;
654 unsigned long offset = 0;
655 unsigned long def_mount_opts;
656 int blocksize = BLOCK_SIZE;
657 int db_count;
658 int i, j;
659 __le32 features;
660
f8314dc6 661 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1da177e4
LT		 662 if (!sbi)
663 return -ENOMEM;
664 sb->s_fs_info = sbi;
1da177e4
LT		 665
666 /*
667 * See what the current blocksize for the device is, and
668 * use that as the blocksize. Otherwise (or if the blocksize
669 * is smaller than the default) use the default.
670 * This is important for devices that have a hardware
671 * sectorsize that is larger than the default.
672 */
673 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
674 if (!blocksize) {
675 printk ("EXT2-fs: unable to set blocksize\n");
676 goto failed_sbi;
677 }
678
679 /*
680 * If the superblock doesn't start on a hardware sector boundary,
681 * calculate the offset.
682 */
683 if (blocksize != BLOCK_SIZE) {
684 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
685 offset = (sb_block*BLOCK_SIZE) % blocksize;
686 } else {
687 logic_sb_block = sb_block;
688 }
689
690 if (!(bh = sb_bread(sb, logic_sb_block))) {
691 printk ("EXT2-fs: unable to read superblock\n");
692 goto failed_sbi;
693 }
694 /*
695 * Note: s_es must be initialized as soon as possible because
696 * some ext2 macro-instructions depend on its value
697 */
698 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
699 sbi->s_es = es;
700 sb->s_magic = le16_to_cpu(es->s_magic);
701
702 if (sb->s_magic != EXT2_SUPER_MAGIC)
703 goto cantfind_ext2;
704
705 /* Set defaults before we parse the mount options */
706 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
707 if (def_mount_opts & EXT2_DEFM_DEBUG)
708 set_opt(sbi->s_mount_opt, DEBUG);
709 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
710 set_opt(sbi->s_mount_opt, GRPID);
711 if (def_mount_opts & EXT2_DEFM_UID16)
712 set_opt(sbi->s_mount_opt, NO_UID32);
713 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
714 set_opt(sbi->s_mount_opt, XATTR_USER);
715 if (def_mount_opts & EXT2_DEFM_ACL)
716 set_opt(sbi->s_mount_opt, POSIX_ACL);
717
718 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
719 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
720 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
721 set_opt(sbi->s_mount_opt, ERRORS_RO);
5a2b4062
VA		 722 else
723 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1da177e4
LT		 724
725 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
726 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
727
728 if (!parse_options ((char *) data, sbi))
729 goto failed_mount;
730
731 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
732 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
733 MS_POSIXACL : 0);
734
6d79125b
CO		 735 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
736 EXT2_MOUNT_XIP if not */
737
1da177e4
LT		 738 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
739 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
740 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
741 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
742 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
743 "running e2fsck is recommended\n");
744 /*
745 * Check feature flags regardless of the revision level, since we
746 * previously didn't change the revision level when setting the flags,
747 * so there is a chance incompat flags are set on a rev 0 filesystem.
748 */
749 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
750 if (features) {
751 printk("EXT2-fs: %s: couldn't mount because of "
752 "unsupported optional features (%x).\n",
753 sb->s_id, le32_to_cpu(features));
754 goto failed_mount;
755 }
756 if (!(sb->s_flags & MS_RDONLY) &&
757 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
758 printk("EXT2-fs: %s: couldn't mount RDWR because of "
759 "unsupported optional features (%x).\n",
760 sb->s_id, le32_to_cpu(features));
761 goto failed_mount;
762 }
763
764 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
765
6d79125b
CO		 766 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
767 (sb->s_blocksize != blocksize))) {
768 if (!silent)
769 printk("XIP: Unsupported blocksize\n");
770 goto failed_mount;
771 }
772
1da177e4
LT		 773 /* If the blocksize doesn't match, re-read the thing.. */
774 if (sb->s_blocksize != blocksize) {
775 brelse(bh);
776
777 if (!sb_set_blocksize(sb, blocksize)) {
778 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
779 goto failed_sbi;
780 }
781
782 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
783 offset = (sb_block*BLOCK_SIZE) % blocksize;
784 bh = sb_bread(sb, logic_sb_block);
785 if(!bh) {
786 printk("EXT2-fs: Couldn't read superblock on "
787 "2nd try.\n");
788 goto failed_sbi;
789 }
790 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
791 sbi->s_es = es;
792 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
793 printk ("EXT2-fs: Magic mismatch, very weird !\n");
794 goto failed_mount;
795 }
796 }
797
798 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
799
800 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
801 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
802 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
803 } else {
804 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
805 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
806 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
807 (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
808 (sbi->s_inode_size > blocksize)) {
809 printk ("EXT2-fs: unsupported inode size: %d\n",
810 sbi->s_inode_size);
811 goto failed_mount;
812 }
813 }
814
815 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
816 le32_to_cpu(es->s_log_frag_size);
817 if (sbi->s_frag_size == 0)
818 goto cantfind_ext2;
819 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
820
821 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
822 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
823 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
824
825 if (EXT2_INODE_SIZE(sb) == 0)
826 goto cantfind_ext2;
827 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
607eb266 828 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1da177e4
LT		 829 goto cantfind_ext2;
830 sbi->s_itb_per_group = sbi->s_inodes_per_group /
831 sbi->s_inodes_per_block;
832 sbi->s_desc_per_block = sb->s_blocksize /
833 sizeof (struct ext2_group_desc);
834 sbi->s_sbh = bh;
835 sbi->s_mount_state = le16_to_cpu(es->s_state);
836 sbi->s_addr_per_block_bits =
837 log2 (EXT2_ADDR_PER_BLOCK(sb));
838 sbi->s_desc_per_block_bits =
839 log2 (EXT2_DESC_PER_BLOCK(sb));
840
841 if (sb->s_magic != EXT2_SUPER_MAGIC)
842 goto cantfind_ext2;
843
844 if (sb->s_blocksize != bh->b_size) {
845 if (!silent)
846 printk ("VFS: Unsupported blocksize on dev "
847 "%s.\n", sb->s_id);
848 goto failed_mount;
849 }
850
851 if (sb->s_blocksize != sbi->s_frag_size) {
852 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
853 sbi->s_frag_size, sb->s_blocksize);
854 goto failed_mount;
855 }
856
857 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
858 printk ("EXT2-fs: #blocks per group too big: %lu\n",
859 sbi->s_blocks_per_group);
860 goto failed_mount;
861 }
862 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
863 printk ("EXT2-fs: #fragments per group too big: %lu\n",
864 sbi->s_frags_per_group);
865 goto failed_mount;
866 }
867 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
868 printk ("EXT2-fs: #inodes per group too big: %lu\n",
869 sbi->s_inodes_per_group);
870 goto failed_mount;
871 }
872
873 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
874 goto cantfind_ext2;
41f04d85
ES		 875 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
876 le32_to_cpu(es->s_first_data_block) - 1)
877 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1da177e4
LT		 878 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
879 EXT2_DESC_PER_BLOCK(sb);
880 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
881 if (sbi->s_group_desc == NULL) {
882 printk ("EXT2-fs: not enough memory\n");
883 goto failed_mount;
884 }
1da177e4
LT		 885 bgl_lock_init(&sbi->s_blockgroup_lock);
886 sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
887 GFP_KERNEL);
888 if (!sbi->s_debts) {
889 printk ("EXT2-fs: not enough memory\n");
890 goto failed_mount_group_desc;
891 }
892 memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
893 for (i = 0; i < db_count; i++) {
894 block = descriptor_loc(sb, logic_sb_block, i);
895 sbi->s_group_desc[i] = sb_bread(sb, block);
896 if (!sbi->s_group_desc[i]) {
897 for (j = 0; j < i; j++)
898 brelse (sbi->s_group_desc[j]);
899 printk ("EXT2-fs: unable to read group descriptors\n");
900 goto failed_mount_group_desc;
901 }
902 }
903 if (!ext2_check_descriptors (sb)) {
904 printk ("EXT2-fs: group descriptors corrupted!\n");
1da177e4
LT		 905 goto failed_mount2;
906 }
907 sbi->s_gdb_count = db_count;
908 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
909 spin_lock_init(&sbi->s_next_gen_lock);
0216bfcf
MC		 910
911 percpu_counter_init(&sbi->s_freeblocks_counter,
912 ext2_count_free_blocks(sb));
913 percpu_counter_init(&sbi->s_freeinodes_counter,
914 ext2_count_free_inodes(sb));
915 percpu_counter_init(&sbi->s_dirs_counter,
916 ext2_count_dirs(sb));
1da177e4
LT		 917 /*
918 * set up enough so that it can read an inode
919 */
920 sb->s_op = &ext2_sops;
921 sb->s_export_op = &ext2_export_ops;
922 sb->s_xattr = ext2_xattr_handlers;
923 root = iget(sb, EXT2_ROOT_INO);
924 sb->s_root = d_alloc_root(root);
925 if (!sb->s_root) {
926 iput(root);
927 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
0216bfcf 928 goto failed_mount3;
1da177e4
LT		 929 }
930 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
931 dput(sb->s_root);
932 sb->s_root = NULL;
933 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
0216bfcf 934 goto failed_mount3;
1da177e4
LT		 935 }
936 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
937 ext2_warning(sb, __FUNCTION__,
ec63f22d 938 "mounting ext3 filesystem as ext2");
1da177e4 939 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1da177e4
LT		 940 return 0;
941
942cantfind_ext2:
943 if (!silent)
944 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
945 sb->s_id);
946 goto failed_mount;
0216bfcf
MC		 947failed_mount3:
948 percpu_counter_destroy(&sbi->s_freeblocks_counter);
949 percpu_counter_destroy(&sbi->s_freeinodes_counter);
950 percpu_counter_destroy(&sbi->s_dirs_counter);
1da177e4
LT		 951failed_mount2:
952 for (i = 0; i < db_count; i++)
953 brelse(sbi->s_group_desc[i]);
954failed_mount_group_desc:
955 kfree(sbi->s_group_desc);
956 kfree(sbi->s_debts);
957failed_mount:
958 brelse(bh);
959failed_sbi:
960 sb->s_fs_info = NULL;
961 kfree(sbi);
962 return -EINVAL;
963}
964
965static void ext2_commit_super (struct super_block * sb,
966 struct ext2_super_block * es)
967{
968 es->s_wtime = cpu_to_le32(get_seconds());
969 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
970 sb->s_dirt = 0;
971}
972
973static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
974{
975 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
976 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
977 es->s_wtime = cpu_to_le32(get_seconds());
978 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
979 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
980 sb->s_dirt = 0;
981}
982
983/*
984 * In the second extended file system, it is not necessary to
985 * write the super block since we use a mapping of the
986 * disk super block in a buffer.
987 *
988 * However, this function is still used to set the fs valid
989 * flags to 0. We need to set this flag to 0 since the fs
990 * may have been checked while mounted and e2fsck may have
991 * set s_state to EXT2_VALID_FS after some corrections.
992 */
993
994void ext2_write_super (struct super_block * sb)
995{
996 struct ext2_super_block * es;
997 lock_kernel();
998 if (!(sb->s_flags & MS_RDONLY)) {
999 es = EXT2_SB(sb)->s_es;
1000
1001 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1002 ext2_debug ("setting valid to 0\n");
1003 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1004 ~EXT2_VALID_FS);
1005 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1006 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1007 es->s_mtime = cpu_to_le32(get_seconds());
1008 ext2_sync_super(sb, es);
1009 } else
1010 ext2_commit_super (sb, es);
1011 }
1012 sb->s_dirt = 0;
1013 unlock_kernel();
1014}
1015
1016static int ext2_remount (struct super_block * sb, int * flags, char * data)
1017{
1018 struct ext2_sb_info * sbi = EXT2_SB(sb);
1019 struct ext2_super_block * es;
6d79125b 1020 unsigned long old_mount_opt = sbi->s_mount_opt;
50a52234
JK		 1021 struct ext2_mount_options old_opts;
1022 unsigned long old_sb_flags;
1023 int err;
1024
1025 /* Store the old options */
1026 old_sb_flags = sb->s_flags;
1027 old_opts.s_mount_opt = sbi->s_mount_opt;
1028 old_opts.s_resuid = sbi->s_resuid;
1029 old_opts.s_resgid = sbi->s_resgid;
1da177e4
LT		 1030
1031 /*
1032 * Allow the "check" option to be passed as a remount option.
1033 */
50a52234
JK		 1034 if (!parse_options (data, sbi)) {
1035 err = -EINVAL;
1036 goto restore_opts;
1037 }
1da177e4
LT		 1038
1039 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1040 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1041
1042 es = sbi->s_es;
6d79125b
CO		 1043 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1044 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1045 invalidate_inodes(sb))
1046 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1047 "xip remain in cache (no functional problem)");
1da177e4
LT		 1048 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1049 return 0;
1050 if (*flags & MS_RDONLY) {
1051 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1052 !(sbi->s_mount_state & EXT2_VALID_FS))
1053 return 0;
1054 /*
1055 * OK, we are remounting a valid rw partition rdonly, so set
1056 * the rdonly flag and then mark the partition as valid again.
1057 */
1058 es->s_state = cpu_to_le16(sbi->s_mount_state);
1059 es->s_mtime = cpu_to_le32(get_seconds());
1060 } else {
1061 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1062 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1063 if (ret) {
1064 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1065 "unsupported optional features (%x).\n",
1066 sb->s_id, le32_to_cpu(ret));
50a52234
JK		 1067 err = -EROFS;
1068 goto restore_opts;
1da177e4
LT		 1069 }
1070 /*
1071 * Mounting a RDONLY partition read-write, so reread and
1072 * store the current valid flag. (It may have been changed
1073 * by e2fsck since we originally mounted the partition.)
1074 */
1075 sbi->s_mount_state = le16_to_cpu(es->s_state);
1076 if (!ext2_setup_super (sb, es, 0))
1077 sb->s_flags &= ~MS_RDONLY;
1078 }
1079 ext2_sync_super(sb, es);
1080 return 0;
50a52234
JK		 1081restore_opts:
1082 sbi->s_mount_opt = old_opts.s_mount_opt;
1083 sbi->s_resuid = old_opts.s_resuid;
1084 sbi->s_resgid = old_opts.s_resgid;
1085 sb->s_flags = old_sb_flags;
1086 return err;
1da177e4
LT		 1087}
1088
726c3342 1089static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1da177e4 1090{
726c3342 1091 struct super_block *sb = dentry->d_sb;
1da177e4
LT		 1092 struct ext2_sb_info *sbi = EXT2_SB(sb);
1093 unsigned long overhead;
1094 int i;
1095
1096 if (test_opt (sb, MINIX_DF))
1097 overhead = 0;
1098 else {
1099 /*
1100 * Compute the overhead (FS structures)
1101 */
1102
1103 /*
1104 * All of the blocks before first_data_block are
1105 * overhead
1106 */
1107 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
1108
1109 /*
1110 * Add the overhead attributed to the superblock and
1111 * block group descriptors. If the sparse superblocks
1112 * feature is turned on, then not all groups have this.
1113 */
1114 for (i = 0; i < sbi->s_groups_count; i++)
1115 overhead += ext2_bg_has_super(sb, i) +
1116 ext2_bg_num_gdb(sb, i);
1117
1118 /*
1119 * Every block group has an inode bitmap, a block
1120 * bitmap, and an inode table.
1121 */
1122 overhead += (sbi->s_groups_count *
1123 (2 + sbi->s_itb_per_group));
1124 }
1125
1126 buf->f_type = EXT2_SUPER_MAGIC;
1127 buf->f_bsize = sb->s_blocksize;
1128 buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1129 buf->f_bfree = ext2_count_free_blocks(sb);
1130 buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1131 if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1132 buf->f_bavail = 0;
1133 buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1134 buf->f_ffree = ext2_count_free_inodes (sb);
1135 buf->f_namelen = EXT2_NAME_LEN;
1136 return 0;
1137}
1138
454e2398
DH		 1139static int ext2_get_sb(struct file_system_type *fs_type,
1140 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1da177e4 1141{
454e2398 1142 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1da177e4
LT		 1143}
1144
1145#ifdef CONFIG_QUOTA
1146
1147/* Read data from quotafile - avoid pagecache and such because we cannot afford
1148 * acquiring the locks... As quota files are never truncated and quota code
1149 * itself serializes the operations (and noone else should touch the files)
1150 * we don't have to be afraid of races */
1151static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1152 size_t len, loff_t off)
1153{
1154 struct inode *inode = sb_dqopt(sb)->files[type];
1155 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1156 int err = 0;
1157 int offset = off & (sb->s_blocksize - 1);
1158 int tocopy;
1159 size_t toread;
1160 struct buffer_head tmp_bh;
1161 struct buffer_head *bh;
1162 loff_t i_size = i_size_read(inode);
1163
1164 if (off > i_size)
1165 return 0;
1166 if (off+len > i_size)
1167 len = i_size-off;
1168 toread = len;
1169 while (toread > 0) {
1170 tocopy = sb->s_blocksize - offset < toread ?
1171 sb->s_blocksize - offset : toread;
1172
1173 tmp_bh.b_state = 0;
1174 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1175 if (err)
1176 return err;
1177 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1178 memset(data, 0, tocopy);
1179 else {
1180 bh = sb_bread(sb, tmp_bh.b_blocknr);
1181 if (!bh)
1182 return -EIO;
1183 memcpy(data, bh->b_data+offset, tocopy);
1184 brelse(bh);
1185 }
1186 offset = 0;
1187 toread -= tocopy;
1188 data += tocopy;
1189 blk++;
1190 }
1191 return len;
1192}
1193
1194/* Write to quotafile */
1195static ssize_t ext2_quota_write(struct super_block *sb, int type,
1196 const char *data, size_t len, loff_t off)
1197{
1198 struct inode *inode = sb_dqopt(sb)->files[type];
1199 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1200 int err = 0;
1201 int offset = off & (sb->s_blocksize - 1);
1202 int tocopy;
1203 size_t towrite = len;
1204 struct buffer_head tmp_bh;
1205 struct buffer_head *bh;
1206
5c81a419 1207 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1da177e4
LT		 1208 while (towrite > 0) {
1209 tocopy = sb->s_blocksize - offset < towrite ?
1210 sb->s_blocksize - offset : towrite;
1211
1212 tmp_bh.b_state = 0;
1213 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1214 if (err)
1215 goto out;
1216 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1217 bh = sb_bread(sb, tmp_bh.b_blocknr);
1218 else
1219 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1220 if (!bh) {
1221 err = -EIO;
1222 goto out;
1223 }
1224 lock_buffer(bh);
1225 memcpy(bh->b_data+offset, data, tocopy);
1226 flush_dcache_page(bh->b_page);
1227 set_buffer_uptodate(bh);
1228 mark_buffer_dirty(bh);
1229 unlock_buffer(bh);
1230 brelse(bh);
1231 offset = 0;
1232 towrite -= tocopy;
1233 data += tocopy;
1234 blk++;
1235 }
1236out:
1237 if (len == towrite)
1238 return err;
1239 if (inode->i_size < off+len-towrite)
1240 i_size_write(inode, off+len-towrite);
1241 inode->i_version++;
1242 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1243 mark_inode_dirty(inode);
1b1dcc1b 1244 mutex_unlock(&inode->i_mutex);
1da177e4
LT		 1245 return len - towrite;
1246}
1247
1248#endif
1249
1250static struct file_system_type ext2_fs_type = {
1251 .owner = THIS_MODULE,
1252 .name = "ext2",
1253 .get_sb = ext2_get_sb,
1254 .kill_sb = kill_block_super,
1255 .fs_flags = FS_REQUIRES_DEV,
1256};
1257
1258static int __init init_ext2_fs(void)
1259{
1260 int err = init_ext2_xattr();
1261 if (err)
1262 return err;
1263 err = init_inodecache();
1264 if (err)
1265 goto out1;
1266 err = register_filesystem(&ext2_fs_type);
1267 if (err)
1268 goto out;
1269 return 0;
1270out:
1271 destroy_inodecache();
1272out1:
1273 exit_ext2_xattr();
1274 return err;
1275}
1276
1277static void __exit exit_ext2_fs(void)
1278{
1279 unregister_filesystem(&ext2_fs_type);
1280 destroy_inodecache();
1281 exit_ext2_xattr();
1282}
1283
1284module_init(init_ext2_fs)
1285module_exit(exit_ext2_fs)
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