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ext2/4: use is_power_of_2()
[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 ([email protected])
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 ([email protected]), 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>
a5694255 28#include <linux/exportfs.h>
1da177e4
LT		 29#include <linux/smp_lock.h>
30#include <linux/vfs.h>
8fc2751b
MB		 31#include <linux/seq_file.h>
32#include <linux/mount.h>
d8ea6cf8 33#include <linux/log2.h>
1da177e4
LT		 34#include <asm/uaccess.h>
35#include "ext2.h"
36#include "xattr.h"
37#include "acl.h"
6d79125b 38#include "xip.h"
1da177e4
LT		 39
40static void ext2_sync_super(struct super_block *sb,
41 struct ext2_super_block *es);
42static int ext2_remount (struct super_block * sb, int * flags, char * data);
726c3342 43static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
1da177e4
LT		 44
45void ext2_error (struct super_block * sb, const char * function,
46 const char * fmt, ...)
47{
48 va_list args;
49 struct ext2_sb_info *sbi = EXT2_SB(sb);
50 struct ext2_super_block *es = sbi->s_es;
51
52 if (!(sb->s_flags & MS_RDONLY)) {
53 sbi->s_mount_state |= EXT2_ERROR_FS;
54 es->s_state =
55 cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
56 ext2_sync_super(sb, es);
57 }
58
59 va_start(args, fmt);
60 printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
61 vprintk(fmt, args);
62 printk("\n");
63 va_end(args);
64
65 if (test_opt(sb, ERRORS_PANIC))
66 panic("EXT2-fs panic from previous error\n");
67 if (test_opt(sb, ERRORS_RO)) {
68 printk("Remounting filesystem read-only\n");
69 sb->s_flags |= MS_RDONLY;
70 }
71}
72
73void ext2_warning (struct super_block * sb, const char * function,
74 const char * fmt, ...)
75{
76 va_list args;
77
78 va_start(args, fmt);
79 printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
80 sb->s_id, function);
81 vprintk(fmt, args);
82 printk("\n");
83 va_end(args);
84}
85
86void ext2_update_dynamic_rev(struct super_block *sb)
87{
88 struct ext2_super_block *es = EXT2_SB(sb)->s_es;
89
90 if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
91 return;
92
93 ext2_warning(sb, __FUNCTION__,
94 "updating to rev %d because of new feature flag, "
95 "running e2fsck is recommended",
96 EXT2_DYNAMIC_REV);
97
98 es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
99 es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
100 es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
101 /* leave es->s_feature_*compat flags alone */
102 /* es->s_uuid will be set by e2fsck if empty */
103
104 /*
105 * The rest of the superblock fields should be zero, and if not it
106 * means they are likely already in use, so leave them alone. We
107 * can leave it up to e2fsck to clean up any inconsistencies there.
108 */
109}
110
111static void ext2_put_super (struct super_block * sb)
112{
113 int db_count;
114 int i;
115 struct ext2_sb_info *sbi = EXT2_SB(sb);
116
117 ext2_xattr_put_super(sb);
118 if (!(sb->s_flags & MS_RDONLY)) {
119 struct ext2_super_block *es = sbi->s_es;
120
121 es->s_state = cpu_to_le16(sbi->s_mount_state);
122 ext2_sync_super(sb, es);
123 }
124 db_count = sbi->s_gdb_count;
125 for (i = 0; i < db_count; i++)
126 if (sbi->s_group_desc[i])
127 brelse (sbi->s_group_desc[i]);
128 kfree(sbi->s_group_desc);
129 kfree(sbi->s_debts);
130 percpu_counter_destroy(&sbi->s_freeblocks_counter);
131 percpu_counter_destroy(&sbi->s_freeinodes_counter);
132 percpu_counter_destroy(&sbi->s_dirs_counter);
133 brelse (sbi->s_sbh);
134 sb->s_fs_info = NULL;
135 kfree(sbi);
136
137 return;
138}
139
e18b890b 140static struct kmem_cache * ext2_inode_cachep;
1da177e4
LT		 141
142static struct inode *ext2_alloc_inode(struct super_block *sb)
143{
144 struct ext2_inode_info *ei;
e94b1766 145 ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
1da177e4
LT		 146 if (!ei)
147 return NULL;
148#ifdef CONFIG_EXT2_FS_POSIX_ACL
149 ei->i_acl = EXT2_ACL_NOT_CACHED;
150 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
151#endif
152 ei->vfs_inode.i_version = 1;
153 return &ei->vfs_inode;
154}
155
156static void ext2_destroy_inode(struct inode *inode)
157{
158 kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
159}
160
4ba9b9d0 161static void init_once(struct kmem_cache * cachep, void *foo)
1da177e4
LT		 162{
163 struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
164
a35afb83 165 rwlock_init(&ei->i_meta_lock);
1da177e4 166#ifdef CONFIG_EXT2_FS_XATTR
a35afb83 167 init_rwsem(&ei->xattr_sem);
1da177e4 168#endif
a35afb83 169 inode_init_once(&ei->vfs_inode);
1da177e4 170}
20c2df83 171
1da177e4
LT		 172static int init_inodecache(void)
173{
174 ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
175 sizeof(struct ext2_inode_info),
fffb60f9
PJ		 176 0, (SLAB_RECLAIM_ACCOUNT|
177 SLAB_MEM_SPREAD),
20c2df83 178 init_once);
1da177e4
LT		 179 if (ext2_inode_cachep == NULL)
180 return -ENOMEM;
181 return 0;
182}
183
184static void destroy_inodecache(void)
185{
1a1d92c1 186 kmem_cache_destroy(ext2_inode_cachep);
1da177e4
LT		 187}
188
189static void ext2_clear_inode(struct inode *inode)
190{
191#ifdef CONFIG_EXT2_FS_POSIX_ACL
192 struct ext2_inode_info *ei = EXT2_I(inode);
193
194 if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
195 posix_acl_release(ei->i_acl);
196 ei->i_acl = EXT2_ACL_NOT_CACHED;
197 }
198 if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
199 posix_acl_release(ei->i_default_acl);
200 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
201 }
202#endif
1da177e4
LT		 203}
204
8fc2751b
MB		 205static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
206{
93d44cb2
MS		 207 struct super_block *sb = vfs->mnt_sb;
208 struct ext2_sb_info *sbi = EXT2_SB(sb);
209 struct ext2_super_block *es = sbi->s_es;
210 unsigned long def_mount_opts;
8fc2751b 211
93d44cb2
MS		 212 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
213
214 if (sbi->s_sb_block != 1)
215 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
216 if (test_opt(sb, MINIX_DF))
217 seq_puts(seq, ",minixdf");
218 if (test_opt(sb, GRPID))
8fc2751b 219 seq_puts(seq, ",grpid");
93d44cb2
MS		 220 if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
221 seq_puts(seq, ",nogrpid");
222 if (sbi->s_resuid != EXT2_DEF_RESUID ||
223 le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
224 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
225 }
226 if (sbi->s_resgid != EXT2_DEF_RESGID ||
227 le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
228 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
229 }
230 if (test_opt(sb, ERRORS_CONT)) {
231 int def_errors = le16_to_cpu(es->s_errors);
232
233 if (def_errors == EXT2_ERRORS_PANIC ||
234 def_errors == EXT2_ERRORS_RO) {
235 seq_puts(seq, ",errors=continue");
236 }
237 }
238 if (test_opt(sb, ERRORS_RO))
239 seq_puts(seq, ",errors=remount-ro");
240 if (test_opt(sb, ERRORS_PANIC))
241 seq_puts(seq, ",errors=panic");
242 if (test_opt(sb, NO_UID32))
243 seq_puts(seq, ",nouid32");
244 if (test_opt(sb, DEBUG))
245 seq_puts(seq, ",debug");
246 if (test_opt(sb, OLDALLOC))
247 seq_puts(seq, ",oldalloc");
248
249#ifdef CONFIG_EXT2_FS_XATTR
250 if (test_opt(sb, XATTR_USER))
251 seq_puts(seq, ",user_xattr");
252 if (!test_opt(sb, XATTR_USER) &&
253 (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
254 seq_puts(seq, ",nouser_xattr");
255 }
256#endif
257
258#ifdef CONFIG_EXT2_FS_POSIX_ACL
259 if (test_opt(sb, POSIX_ACL))
260 seq_puts(seq, ",acl");
261 if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
262 seq_puts(seq, ",noacl");
263#endif
264
265 if (test_opt(sb, NOBH))
266 seq_puts(seq, ",nobh");
8fc2751b
MB		 267
268#if defined(CONFIG_QUOTA)
269 if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
270 seq_puts(seq, ",usrquota");
271
272 if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
273 seq_puts(seq, ",grpquota");
274#endif
275
83541796
CO		 276#if defined(CONFIG_EXT2_FS_XIP)
277 if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
278 seq_puts(seq, ",xip");
279#endif
280
8fc2751b
MB		 281 return 0;
282}
283
1da177e4
LT		 284#ifdef CONFIG_QUOTA
285static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
286static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
287#endif
288
ee9b6d61 289static const struct super_operations ext2_sops = {
1da177e4
LT		 290 .alloc_inode = ext2_alloc_inode,
291 .destroy_inode = ext2_destroy_inode,
292 .read_inode = ext2_read_inode,
293 .write_inode = ext2_write_inode,
e072c6f2 294 .put_inode = ext2_put_inode,
1da177e4
LT		 295 .delete_inode = ext2_delete_inode,
296 .put_super = ext2_put_super,
297 .write_super = ext2_write_super,
298 .statfs = ext2_statfs,
299 .remount_fs = ext2_remount,
300 .clear_inode = ext2_clear_inode,
8fc2751b 301 .show_options = ext2_show_options,
1da177e4
LT		 302#ifdef CONFIG_QUOTA
303 .quota_read = ext2_quota_read,
304 .quota_write = ext2_quota_write,
305#endif
306};
307
ecaff756
N		 308static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
309{
310 __u32 *objp = vobjp;
311 unsigned long ino = objp[0];
312 __u32 generation = objp[1];
313 struct inode *inode;
314 struct dentry *result;
315
316 if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
317 return ERR_PTR(-ESTALE);
318 if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
319 return ERR_PTR(-ESTALE);
320
321 /* iget isn't really right if the inode is currently unallocated!!
322 * ext2_read_inode currently does appropriate checks, but
323 * it might be "neater" to call ext2_get_inode first and check
324 * if the inode is valid.....
325 */
326 inode = iget(sb, ino);
327 if (inode == NULL)
328 return ERR_PTR(-ENOMEM);
329 if (is_bad_inode(inode) ||
330 (generation && inode->i_generation != generation)) {
331 /* we didn't find the right inode.. */
332 iput(inode);
333 return ERR_PTR(-ESTALE);
334 }
335 /* now to find a dentry.
336 * If possible, get a well-connected one
337 */
338 result = d_alloc_anon(inode);
339 if (!result) {
340 iput(inode);
341 return ERR_PTR(-ENOMEM);
342 }
343 return result;
344}
345
1da177e4
LT		 346/* Yes, most of these are left as NULL!!
347 * A NULL value implies the default, which works with ext2-like file
348 * systems, but can be improved upon.
349 * Currently only get_parent is required.
350 */
1da177e4
LT		 351static struct export_operations ext2_export_ops = {
352 .get_parent = ext2_get_parent,
ecaff756 353 .get_dentry = ext2_get_dentry,
1da177e4
LT		 354};
355
356static unsigned long get_sb_block(void **data)
357{
358 unsigned long sb_block;
359 char *options = (char *) *data;
360
361 if (!options || strncmp(options, "sb=", 3) != 0)
362 return 1; /* Default location */
363 options += 3;
364 sb_block = simple_strtoul(options, &options, 0);
365 if (*options && *options != ',') {
366 printk("EXT2-fs: Invalid sb specification: %s\n",
367 (char *) *data);
368 return 1;
369 }
370 if (*options == ',')
371 options++;
372 *data = (void *) options;
373 return sb_block;
374}
375
376enum {
377 Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
8fc2751b 378 Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
2860b733 379 Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
8fc2751b
MB		 380 Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
381 Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
382 Opt_usrquota, Opt_grpquota
1da177e4
LT		 383};
384
385static match_table_t tokens = {
386 {Opt_bsd_df, "bsddf"},
387 {Opt_minix_df, "minixdf"},
388 {Opt_grpid, "grpid"},
389 {Opt_grpid, "bsdgroups"},
390 {Opt_nogrpid, "nogrpid"},
391 {Opt_nogrpid, "sysvgroups"},
392 {Opt_resgid, "resgid=%u"},
393 {Opt_resuid, "resuid=%u"},
394 {Opt_sb, "sb=%u"},
395 {Opt_err_cont, "errors=continue"},
396 {Opt_err_panic, "errors=panic"},
397 {Opt_err_ro, "errors=remount-ro"},
398 {Opt_nouid32, "nouid32"},
399 {Opt_nocheck, "check=none"},
400 {Opt_nocheck, "nocheck"},
1da177e4
LT		 401 {Opt_debug, "debug"},
402 {Opt_oldalloc, "oldalloc"},
403 {Opt_orlov, "orlov"},
404 {Opt_nobh, "nobh"},
405 {Opt_user_xattr, "user_xattr"},
406 {Opt_nouser_xattr, "nouser_xattr"},
407 {Opt_acl, "acl"},
408 {Opt_noacl, "noacl"},
6d79125b 409 {Opt_xip, "xip"},
8fc2751b 410 {Opt_grpquota, "grpquota"},
1da177e4 411 {Opt_ignore, "noquota"},
8fc2751b
MB		 412 {Opt_quota, "quota"},
413 {Opt_usrquota, "usrquota"},
1da177e4
LT		 414 {Opt_err, NULL}
415};
416
417static int parse_options (char * options,
418 struct ext2_sb_info *sbi)
419{
420 char * p;
421 substring_t args[MAX_OPT_ARGS];
1da177e4
LT		 422 int option;
423
424 if (!options)
425 return 1;
426
427 while ((p = strsep (&options, ",")) != NULL) {
428 int token;
429 if (!*p)
430 continue;
431
432 token = match_token(p, tokens, args);
433 switch (token) {
434 case Opt_bsd_df:
435 clear_opt (sbi->s_mount_opt, MINIX_DF);
436 break;
437 case Opt_minix_df:
438 set_opt (sbi->s_mount_opt, MINIX_DF);
439 break;
440 case Opt_grpid:
441 set_opt (sbi->s_mount_opt, GRPID);
442 break;
443 case Opt_nogrpid:
444 clear_opt (sbi->s_mount_opt, GRPID);
445 break;
446 case Opt_resuid:
447 if (match_int(&args[0], &option))
448 return 0;
449 sbi->s_resuid = option;
450 break;
451 case Opt_resgid:
452 if (match_int(&args[0], &option))
453 return 0;
454 sbi->s_resgid = option;
455 break;
456 case Opt_sb:
457 /* handled by get_sb_block() instead of here */
458 /* *sb_block = match_int(&args[0]); */
459 break;
460 case Opt_err_panic:
5a2b4062
VA		 461 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
462 clear_opt (sbi->s_mount_opt, ERRORS_RO);
463 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
1da177e4
LT		 464 break;
465 case Opt_err_ro:
5a2b4062
VA		 466 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
467 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
468 set_opt (sbi->s_mount_opt, ERRORS_RO);
1da177e4
LT		 469 break;
470 case Opt_err_cont:
5a2b4062
VA		 471 clear_opt (sbi->s_mount_opt, ERRORS_RO);
472 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
473 set_opt (sbi->s_mount_opt, ERRORS_CONT);
1da177e4
LT		 474 break;
475 case Opt_nouid32:
476 set_opt (sbi->s_mount_opt, NO_UID32);
477 break;
1da177e4
LT		 478 case Opt_nocheck:
479 clear_opt (sbi->s_mount_opt, CHECK);
480 break;
481 case Opt_debug:
482 set_opt (sbi->s_mount_opt, DEBUG);
483 break;
484 case Opt_oldalloc:
485 set_opt (sbi->s_mount_opt, OLDALLOC);
486 break;
487 case Opt_orlov:
488 clear_opt (sbi->s_mount_opt, OLDALLOC);
489 break;
490 case Opt_nobh:
491 set_opt (sbi->s_mount_opt, NOBH);
492 break;
493#ifdef CONFIG_EXT2_FS_XATTR
494 case Opt_user_xattr:
495 set_opt (sbi->s_mount_opt, XATTR_USER);
496 break;
497 case Opt_nouser_xattr:
498 clear_opt (sbi->s_mount_opt, XATTR_USER);
499 break;
500#else
501 case Opt_user_xattr:
502 case Opt_nouser_xattr:
503 printk("EXT2 (no)user_xattr options not supported\n");
504 break;
505#endif
506#ifdef CONFIG_EXT2_FS_POSIX_ACL
507 case Opt_acl:
508 set_opt(sbi->s_mount_opt, POSIX_ACL);
509 break;
510 case Opt_noacl:
511 clear_opt(sbi->s_mount_opt, POSIX_ACL);
512 break;
513#else
514 case Opt_acl:
515 case Opt_noacl:
516 printk("EXT2 (no)acl options not supported\n");
517 break;
518#endif
6d79125b
CO		 519 case Opt_xip:
520#ifdef CONFIG_EXT2_FS_XIP
521 set_opt (sbi->s_mount_opt, XIP);
522#else
523 printk("EXT2 xip option not supported\n");
524#endif
525 break;
8fc2751b
MB		 526
527#if defined(CONFIG_QUOTA)
528 case Opt_quota:
529 case Opt_usrquota:
530 set_opt(sbi->s_mount_opt, USRQUOTA);
531 break;
532
533 case Opt_grpquota:
534 set_opt(sbi->s_mount_opt, GRPQUOTA);
535 break;
536#else
537 case Opt_quota:
538 case Opt_usrquota:
539 case Opt_grpquota:
540 printk(KERN_ERR
541 "EXT2-fs: quota operations not supported.\n");
542
543 break;
544#endif
545
1da177e4
LT		 546 case Opt_ignore:
547 break;
548 default:
549 return 0;
550 }
551 }
1da177e4
LT		 552 return 1;
553}
554
555static int ext2_setup_super (struct super_block * sb,
556 struct ext2_super_block * es,
557 int read_only)
558{
559 int res = 0;
560 struct ext2_sb_info *sbi = EXT2_SB(sb);
561
562 if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
563 printk ("EXT2-fs warning: revision level too high, "
564 "forcing read-only mode\n");
565 res = MS_RDONLY;
566 }
567 if (read_only)
568 return res;
569 if (!(sbi->s_mount_state & EXT2_VALID_FS))
570 printk ("EXT2-fs warning: mounting unchecked fs, "
571 "running e2fsck is recommended\n");
572 else if ((sbi->s_mount_state & EXT2_ERROR_FS))
573 printk ("EXT2-fs warning: mounting fs with errors, "
574 "running e2fsck is recommended\n");
575 else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
576 le16_to_cpu(es->s_mnt_count) >=
577 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
578 printk ("EXT2-fs warning: maximal mount count reached, "
579 "running e2fsck is recommended\n");
580 else if (le32_to_cpu(es->s_checkinterval) &&
581 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
582 printk ("EXT2-fs warning: checktime reached, "
583 "running e2fsck is recommended\n");
584 if (!le16_to_cpu(es->s_max_mnt_count))
585 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
586 es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
587 ext2_write_super(sb);
588 if (test_opt (sb, DEBUG))
589 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
590 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
591 EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
592 sbi->s_frag_size,
593 sbi->s_groups_count,
594 EXT2_BLOCKS_PER_GROUP(sb),
595 EXT2_INODES_PER_GROUP(sb),
596 sbi->s_mount_opt);
1da177e4
LT		 597 return res;
598}
599
600static int ext2_check_descriptors (struct super_block * sb)
601{
602 int i;
603 int desc_block = 0;
604 struct ext2_sb_info *sbi = EXT2_SB(sb);
41f04d85
ES		 605 unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
606 unsigned long last_block;
1da177e4
LT		 607 struct ext2_group_desc * gdp = NULL;
608
609 ext2_debug ("Checking group descriptors");
610
611 for (i = 0; i < sbi->s_groups_count; i++)
612 {
41f04d85
ES		 613 if (i == sbi->s_groups_count - 1)
614 last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
615 else
616 last_block = first_block +
617 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
618
1da177e4
LT		 619 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
620 gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
41f04d85
ES		 621 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
622 le32_to_cpu(gdp->bg_block_bitmap) > last_block)
1da177e4
LT		 623 {
624 ext2_error (sb, "ext2_check_descriptors",
625 "Block bitmap for group %d"
626 " not in group (block %lu)!",
627 i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
628 return 0;
629 }
41f04d85
ES		 630 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
631 le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
1da177e4
LT		 632 {
633 ext2_error (sb, "ext2_check_descriptors",
634 "Inode bitmap for group %d"
635 " not in group (block %lu)!",
636 i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
637 return 0;
638 }
41f04d85 639 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
780dcdb2 640 le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
41f04d85 641 last_block)
1da177e4
LT		 642 {
643 ext2_error (sb, "ext2_check_descriptors",
644 "Inode table for group %d"
645 " not in group (block %lu)!",
646 i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
647 return 0;
648 }
41f04d85 649 first_block += EXT2_BLOCKS_PER_GROUP(sb);
1da177e4
LT		 650 gdp++;
651 }
652 return 1;
653}
654
1da177e4
LT		 655/*
656 * Maximal file size. There is a direct, and {,double-,triple-}indirect
657 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
658 * We need to be 1 filesystem block less than the 2^32 sector limit.
659 */
660static loff_t ext2_max_size(int bits)
661{
662 loff_t res = EXT2_NDIR_BLOCKS;
663 /* This constant is calculated to be the largest file size for a
664 * dense, 4k-blocksize file such that the total number of
665 * sectors in the file, including data and all indirect blocks,
666 * does not exceed 2^32. */
667 const loff_t upper_limit = 0x1ff7fffd000LL;
668
669 res += 1LL << (bits-2);
670 res += 1LL << (2*(bits-2));
671 res += 1LL << (3*(bits-2));
672 res <<= bits;
673 if (res > upper_limit)
674 res = upper_limit;
675 return res;
676}
677
678static unsigned long descriptor_loc(struct super_block *sb,
679 unsigned long logic_sb_block,
680 int nr)
681{
682 struct ext2_sb_info *sbi = EXT2_SB(sb);
683 unsigned long bg, first_data_block, first_meta_bg;
684 int has_super = 0;
685
686 first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
687 first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
688
689 if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
690 nr < first_meta_bg)
691 return (logic_sb_block + nr + 1);
692 bg = sbi->s_desc_per_block * nr;
693 if (ext2_bg_has_super(sb, bg))
694 has_super = 1;
695 return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
696}
697
698static int ext2_fill_super(struct super_block *sb, void *data, int silent)
699{
700 struct buffer_head * bh;
701 struct ext2_sb_info * sbi;
702 struct ext2_super_block * es;
703 struct inode *root;
704 unsigned long block;
705 unsigned long sb_block = get_sb_block(&data);
706 unsigned long logic_sb_block;
707 unsigned long offset = 0;
708 unsigned long def_mount_opts;
709 int blocksize = BLOCK_SIZE;
710 int db_count;
711 int i, j;
712 __le32 features;
833f4077 713 int err;
1da177e4 714
f8314dc6 715 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1da177e4
LT		 716 if (!sbi)
717 return -ENOMEM;
718 sb->s_fs_info = sbi;
93d44cb2 719 sbi->s_sb_block = sb_block;
1da177e4
LT		 720
721 /*
722 * See what the current blocksize for the device is, and
723 * use that as the blocksize. Otherwise (or if the blocksize
724 * is smaller than the default) use the default.
725 * This is important for devices that have a hardware
726 * sectorsize that is larger than the default.
727 */
728 blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
729 if (!blocksize) {
730 printk ("EXT2-fs: unable to set blocksize\n");
731 goto failed_sbi;
732 }
733
734 /*
735 * If the superblock doesn't start on a hardware sector boundary,
736 * calculate the offset.
737 */
738 if (blocksize != BLOCK_SIZE) {
739 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
740 offset = (sb_block*BLOCK_SIZE) % blocksize;
741 } else {
742 logic_sb_block = sb_block;
743 }
744
745 if (!(bh = sb_bread(sb, logic_sb_block))) {
746 printk ("EXT2-fs: unable to read superblock\n");
747 goto failed_sbi;
748 }
749 /*
750 * Note: s_es must be initialized as soon as possible because
751 * some ext2 macro-instructions depend on its value
752 */
753 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
754 sbi->s_es = es;
755 sb->s_magic = le16_to_cpu(es->s_magic);
756
757 if (sb->s_magic != EXT2_SUPER_MAGIC)
758 goto cantfind_ext2;
759
760 /* Set defaults before we parse the mount options */
761 def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
762 if (def_mount_opts & EXT2_DEFM_DEBUG)
763 set_opt(sbi->s_mount_opt, DEBUG);
764 if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
765 set_opt(sbi->s_mount_opt, GRPID);
766 if (def_mount_opts & EXT2_DEFM_UID16)
767 set_opt(sbi->s_mount_opt, NO_UID32);
2e7842b8 768#ifdef CONFIG_EXT2_FS_XATTR
1da177e4
LT		 769 if (def_mount_opts & EXT2_DEFM_XATTR_USER)
770 set_opt(sbi->s_mount_opt, XATTR_USER);
2e7842b8
HD		 771#endif
772#ifdef CONFIG_EXT2_FS_POSIX_ACL
1da177e4
LT		 773 if (def_mount_opts & EXT2_DEFM_ACL)
774 set_opt(sbi->s_mount_opt, POSIX_ACL);
2e7842b8 775#endif
1da177e4
LT		 776
777 if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
778 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
779 else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
780 set_opt(sbi->s_mount_opt, ERRORS_RO);
5a2b4062
VA		 781 else
782 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1da177e4
LT		 783
784 sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
785 sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
786
787 if (!parse_options ((char *) data, sbi))
788 goto failed_mount;
789
790 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
791 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
792 MS_POSIXACL : 0);
793
6d79125b
CO		 794 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
795 EXT2_MOUNT_XIP if not */
796
1da177e4
LT		 797 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
798 (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
799 EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
800 EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
801 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
802 "running e2fsck is recommended\n");
803 /*
804 * Check feature flags regardless of the revision level, since we
805 * previously didn't change the revision level when setting the flags,
806 * so there is a chance incompat flags are set on a rev 0 filesystem.
807 */
808 features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
809 if (features) {
810 printk("EXT2-fs: %s: couldn't mount because of "
811 "unsupported optional features (%x).\n",
812 sb->s_id, le32_to_cpu(features));
813 goto failed_mount;
814 }
815 if (!(sb->s_flags & MS_RDONLY) &&
816 (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
817 printk("EXT2-fs: %s: couldn't mount RDWR because of "
818 "unsupported optional features (%x).\n",
819 sb->s_id, le32_to_cpu(features));
820 goto failed_mount;
821 }
822
823 blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
824
6d79125b
CO		 825 if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
826 (sb->s_blocksize != blocksize))) {
827 if (!silent)
828 printk("XIP: Unsupported blocksize\n");
829 goto failed_mount;
830 }
831
1da177e4
LT		 832 /* If the blocksize doesn't match, re-read the thing.. */
833 if (sb->s_blocksize != blocksize) {
834 brelse(bh);
835
836 if (!sb_set_blocksize(sb, blocksize)) {
837 printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
838 goto failed_sbi;
839 }
840
841 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
842 offset = (sb_block*BLOCK_SIZE) % blocksize;
843 bh = sb_bread(sb, logic_sb_block);
844 if(!bh) {
845 printk("EXT2-fs: Couldn't read superblock on "
846 "2nd try.\n");
847 goto failed_sbi;
848 }
849 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
850 sbi->s_es = es;
851 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
852 printk ("EXT2-fs: Magic mismatch, very weird !\n");
853 goto failed_mount;
854 }
855 }
856
857 sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
858
859 if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
860 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
861 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
862 } else {
863 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
864 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
865 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
d8ea6cf8 866 !is_power_of_2(sbi->s_inode_size) ||
1da177e4
LT		 867 (sbi->s_inode_size > blocksize)) {
868 printk ("EXT2-fs: unsupported inode size: %d\n",
869 sbi->s_inode_size);
870 goto failed_mount;
871 }
872 }
873
874 sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
875 le32_to_cpu(es->s_log_frag_size);
876 if (sbi->s_frag_size == 0)
877 goto cantfind_ext2;
878 sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
879
880 sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
881 sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
882 sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
883
884 if (EXT2_INODE_SIZE(sb) == 0)
885 goto cantfind_ext2;
886 sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
607eb266 887 if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1da177e4
LT		 888 goto cantfind_ext2;
889 sbi->s_itb_per_group = sbi->s_inodes_per_group /
890 sbi->s_inodes_per_block;
891 sbi->s_desc_per_block = sb->s_blocksize /
892 sizeof (struct ext2_group_desc);
893 sbi->s_sbh = bh;
894 sbi->s_mount_state = le16_to_cpu(es->s_state);
895 sbi->s_addr_per_block_bits =
f0d1b0b3 896 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1da177e4 897 sbi->s_desc_per_block_bits =
f0d1b0b3 898 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1da177e4
LT		 899
900 if (sb->s_magic != EXT2_SUPER_MAGIC)
901 goto cantfind_ext2;
902
903 if (sb->s_blocksize != bh->b_size) {
904 if (!silent)
905 printk ("VFS: Unsupported blocksize on dev "
906 "%s.\n", sb->s_id);
907 goto failed_mount;
908 }
909
910 if (sb->s_blocksize != sbi->s_frag_size) {
911 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
912 sbi->s_frag_size, sb->s_blocksize);
913 goto failed_mount;
914 }
915
916 if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
917 printk ("EXT2-fs: #blocks per group too big: %lu\n",
918 sbi->s_blocks_per_group);
919 goto failed_mount;
920 }
921 if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
922 printk ("EXT2-fs: #fragments per group too big: %lu\n",
923 sbi->s_frags_per_group);
924 goto failed_mount;
925 }
926 if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
927 printk ("EXT2-fs: #inodes per group too big: %lu\n",
928 sbi->s_inodes_per_group);
929 goto failed_mount;
930 }
931
932 if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
933 goto cantfind_ext2;
41f04d85
ES		 934 sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
935 le32_to_cpu(es->s_first_data_block) - 1)
936 / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1da177e4
LT		 937 db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
938 EXT2_DESC_PER_BLOCK(sb);
939 sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
940 if (sbi->s_group_desc == NULL) {
941 printk ("EXT2-fs: not enough memory\n");
942 goto failed_mount;
943 }
1da177e4 944 bgl_lock_init(&sbi->s_blockgroup_lock);
dd00cc48 945 sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1da177e4
LT		 946 if (!sbi->s_debts) {
947 printk ("EXT2-fs: not enough memory\n");
948 goto failed_mount_group_desc;
949 }
1da177e4
LT		 950 for (i = 0; i < db_count; i++) {
951 block = descriptor_loc(sb, logic_sb_block, i);
952 sbi->s_group_desc[i] = sb_bread(sb, block);
953 if (!sbi->s_group_desc[i]) {
954 for (j = 0; j < i; j++)
955 brelse (sbi->s_group_desc[j]);
956 printk ("EXT2-fs: unable to read group descriptors\n");
957 goto failed_mount_group_desc;
958 }
959 }
960 if (!ext2_check_descriptors (sb)) {
961 printk ("EXT2-fs: group descriptors corrupted!\n");
1da177e4
LT		 962 goto failed_mount2;
963 }
964 sbi->s_gdb_count = db_count;
965 get_random_bytes(&sbi->s_next_generation, sizeof(u32));
966 spin_lock_init(&sbi->s_next_gen_lock);
0216bfcf 967
833f4077 968 err = percpu_counter_init(&sbi->s_freeblocks_counter,
0216bfcf 969 ext2_count_free_blocks(sb));
833f4077
PZ		 970 if (!err) {
971 err = percpu_counter_init(&sbi->s_freeinodes_counter,
0216bfcf 972 ext2_count_free_inodes(sb));
833f4077
PZ		 973 }
974 if (!err) {
975 err = percpu_counter_init(&sbi->s_dirs_counter,
0216bfcf 976 ext2_count_dirs(sb));
833f4077
PZ		 977 }
978 if (err) {
979 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
980 goto failed_mount3;
981 }
1da177e4
LT		 982 /*
983 * set up enough so that it can read an inode
984 */
985 sb->s_op = &ext2_sops;
986 sb->s_export_op = &ext2_export_ops;
987 sb->s_xattr = ext2_xattr_handlers;
988 root = iget(sb, EXT2_ROOT_INO);
989 sb->s_root = d_alloc_root(root);
990 if (!sb->s_root) {
991 iput(root);
992 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
0216bfcf 993 goto failed_mount3;
1da177e4
LT		 994 }
995 if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
996 dput(sb->s_root);
997 sb->s_root = NULL;
998 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
0216bfcf 999 goto failed_mount3;
1da177e4
LT		 1000 }
1001 if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1002 ext2_warning(sb, __FUNCTION__,
ec63f22d 1003 "mounting ext3 filesystem as ext2");
1da177e4 1004 ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1da177e4
LT		 1005 return 0;
1006
1007cantfind_ext2:
1008 if (!silent)
1009 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1010 sb->s_id);
1011 goto failed_mount;
0216bfcf
MC		 1012failed_mount3:
1013 percpu_counter_destroy(&sbi->s_freeblocks_counter);
1014 percpu_counter_destroy(&sbi->s_freeinodes_counter);
1015 percpu_counter_destroy(&sbi->s_dirs_counter);
1da177e4
LT		 1016failed_mount2:
1017 for (i = 0; i < db_count; i++)
1018 brelse(sbi->s_group_desc[i]);
1019failed_mount_group_desc:
1020 kfree(sbi->s_group_desc);
1021 kfree(sbi->s_debts);
1022failed_mount:
1023 brelse(bh);
1024failed_sbi:
1025 sb->s_fs_info = NULL;
1026 kfree(sbi);
1027 return -EINVAL;
1028}
1029
1030static void ext2_commit_super (struct super_block * sb,
1031 struct ext2_super_block * es)
1032{
1033 es->s_wtime = cpu_to_le32(get_seconds());
1034 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1035 sb->s_dirt = 0;
1036}
1037
1038static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1039{
1040 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1041 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1042 es->s_wtime = cpu_to_le32(get_seconds());
1043 mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1044 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1045 sb->s_dirt = 0;
1046}
1047
1048/*
1049 * In the second extended file system, it is not necessary to
1050 * write the super block since we use a mapping of the
1051 * disk super block in a buffer.
1052 *
1053 * However, this function is still used to set the fs valid
1054 * flags to 0. We need to set this flag to 0 since the fs
1055 * may have been checked while mounted and e2fsck may have
1056 * set s_state to EXT2_VALID_FS after some corrections.
1057 */
1058
1059void ext2_write_super (struct super_block * sb)
1060{
1061 struct ext2_super_block * es;
1062 lock_kernel();
1063 if (!(sb->s_flags & MS_RDONLY)) {
1064 es = EXT2_SB(sb)->s_es;
1065
1066 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1067 ext2_debug ("setting valid to 0\n");
1068 es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1069 ~EXT2_VALID_FS);
1070 es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1071 es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1072 es->s_mtime = cpu_to_le32(get_seconds());
1073 ext2_sync_super(sb, es);
1074 } else
1075 ext2_commit_super (sb, es);
1076 }
1077 sb->s_dirt = 0;
1078 unlock_kernel();
1079}
1080
1081static int ext2_remount (struct super_block * sb, int * flags, char * data)
1082{
1083 struct ext2_sb_info * sbi = EXT2_SB(sb);
1084 struct ext2_super_block * es;
6d79125b 1085 unsigned long old_mount_opt = sbi->s_mount_opt;
50a52234
JK		 1086 struct ext2_mount_options old_opts;
1087 unsigned long old_sb_flags;
1088 int err;
1089
1090 /* Store the old options */
1091 old_sb_flags = sb->s_flags;
1092 old_opts.s_mount_opt = sbi->s_mount_opt;
1093 old_opts.s_resuid = sbi->s_resuid;
1094 old_opts.s_resgid = sbi->s_resgid;
1da177e4
LT		 1095
1096 /*
1097 * Allow the "check" option to be passed as a remount option.
1098 */
50a52234
JK		 1099 if (!parse_options (data, sbi)) {
1100 err = -EINVAL;
1101 goto restore_opts;
1102 }
1da177e4
LT		 1103
1104 sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1105 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1106
266f5aa0
CO		 1107 ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1108 EXT2_MOUNT_XIP if not */
1109
1110 if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1111 printk("XIP: Unsupported blocksize\n");
ddc80bd7 1112 err = -EINVAL;
266f5aa0
CO		 1113 goto restore_opts;
1114 }
1115
1da177e4 1116 es = sbi->s_es;
6d79125b
CO		 1117 if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1118 (old_mount_opt & EXT2_MOUNT_XIP)) &&
1119 invalidate_inodes(sb))
1120 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1121 "xip remain in cache (no functional problem)");
1da177e4
LT		 1122 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1123 return 0;
1124 if (*flags & MS_RDONLY) {
1125 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1126 !(sbi->s_mount_state & EXT2_VALID_FS))
1127 return 0;
1128 /*
1129 * OK, we are remounting a valid rw partition rdonly, so set
1130 * the rdonly flag and then mark the partition as valid again.
1131 */
1132 es->s_state = cpu_to_le16(sbi->s_mount_state);
1133 es->s_mtime = cpu_to_le32(get_seconds());
1134 } else {
1135 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1136 ~EXT2_FEATURE_RO_COMPAT_SUPP);
1137 if (ret) {
1138 printk("EXT2-fs: %s: couldn't remount RDWR because of "
1139 "unsupported optional features (%x).\n",
1140 sb->s_id, le32_to_cpu(ret));
50a52234
JK		 1141 err = -EROFS;
1142 goto restore_opts;
1da177e4
LT		 1143 }
1144 /*
1145 * Mounting a RDONLY partition read-write, so reread and
1146 * store the current valid flag. (It may have been changed
1147 * by e2fsck since we originally mounted the partition.)
1148 */
1149 sbi->s_mount_state = le16_to_cpu(es->s_state);
1150 if (!ext2_setup_super (sb, es, 0))
1151 sb->s_flags &= ~MS_RDONLY;
1152 }
1153 ext2_sync_super(sb, es);
1154 return 0;
50a52234
JK		 1155restore_opts:
1156 sbi->s_mount_opt = old_opts.s_mount_opt;
1157 sbi->s_resuid = old_opts.s_resuid;
1158 sbi->s_resgid = old_opts.s_resgid;
1159 sb->s_flags = old_sb_flags;
1160 return err;
1da177e4
LT		 1161}
1162
726c3342 1163static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1da177e4 1164{
726c3342 1165 struct super_block *sb = dentry->d_sb;
1da177e4 1166 struct ext2_sb_info *sbi = EXT2_SB(sb);
e4fca01e 1167 struct ext2_super_block *es = sbi->s_es;
e4fca01e 1168 u64 fsid;
1da177e4
LT		 1169
1170 if (test_opt (sb, MINIX_DF))
2235219b
BP		 1171 sbi->s_overhead_last = 0;
1172 else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1173 unsigned long i, overhead = 0;
1174 smp_rmb();
1175
1da177e4 1176 /*
2235219b
BP		 1177 * Compute the overhead (FS structures). This is constant
1178 * for a given filesystem unless the number of block groups
1179 * changes so we cache the previous value until it does.
1da177e4
LT		 1180 */
1181
1182 /*
1183 * All of the blocks before first_data_block are
1184 * overhead
1185 */
e4fca01e 1186 overhead = le32_to_cpu(es->s_first_data_block);
1da177e4
LT		 1187
1188 /*
1189 * Add the overhead attributed to the superblock and
1190 * block group descriptors. If the sparse superblocks
1191 * feature is turned on, then not all groups have this.
1192 */
1193 for (i = 0; i < sbi->s_groups_count; i++)
1194 overhead += ext2_bg_has_super(sb, i) +
1195 ext2_bg_num_gdb(sb, i);
1196
1197 /*
1198 * Every block group has an inode bitmap, a block
1199 * bitmap, and an inode table.
1200 */
1201 overhead += (sbi->s_groups_count *
1202 (2 + sbi->s_itb_per_group));
2235219b
BP		 1203 sbi->s_overhead_last = overhead;
1204 smp_wmb();
1205 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1da177e4
LT		 1206 }
1207
1208 buf->f_type = EXT2_SUPER_MAGIC;
1209 buf->f_bsize = sb->s_blocksize;
2235219b 1210 buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1da177e4 1211 buf->f_bfree = ext2_count_free_blocks(sb);
2235219b 1212 es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
e4fca01e
PE		 1213 buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1214 if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1da177e4 1215 buf->f_bavail = 0;
e4fca01e
PE		 1216 buf->f_files = le32_to_cpu(es->s_inodes_count);
1217 buf->f_ffree = ext2_count_free_inodes(sb);
2235219b 1218 es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1da177e4 1219 buf->f_namelen = EXT2_NAME_LEN;
e4fca01e
PE		 1220 fsid = le64_to_cpup((void *)es->s_uuid) ^
1221 le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1222 buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1223 buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1da177e4
LT		 1224 return 0;
1225}
1226
454e2398
DH		 1227static int ext2_get_sb(struct file_system_type *fs_type,
1228 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1da177e4 1229{
454e2398 1230 return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1da177e4
LT		 1231}
1232
1233#ifdef CONFIG_QUOTA
1234
1235/* Read data from quotafile - avoid pagecache and such because we cannot afford
1236 * acquiring the locks... As quota files are never truncated and quota code
1237 * itself serializes the operations (and noone else should touch the files)
1238 * we don't have to be afraid of races */
1239static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1240 size_t len, loff_t off)
1241{
1242 struct inode *inode = sb_dqopt(sb)->files[type];
1243 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1244 int err = 0;
1245 int offset = off & (sb->s_blocksize - 1);
1246 int tocopy;
1247 size_t toread;
1248 struct buffer_head tmp_bh;
1249 struct buffer_head *bh;
1250 loff_t i_size = i_size_read(inode);
1251
1252 if (off > i_size)
1253 return 0;
1254 if (off+len > i_size)
1255 len = i_size-off;
1256 toread = len;
1257 while (toread > 0) {
1258 tocopy = sb->s_blocksize - offset < toread ?
1259 sb->s_blocksize - offset : toread;
1260
1261 tmp_bh.b_state = 0;
1262 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1263 if (err)
1264 return err;
1265 if (!buffer_mapped(&tmp_bh)) /* A hole? */
1266 memset(data, 0, tocopy);
1267 else {
1268 bh = sb_bread(sb, tmp_bh.b_blocknr);
1269 if (!bh)
1270 return -EIO;
1271 memcpy(data, bh->b_data+offset, tocopy);
1272 brelse(bh);
1273 }
1274 offset = 0;
1275 toread -= tocopy;
1276 data += tocopy;
1277 blk++;
1278 }
1279 return len;
1280}
1281
1282/* Write to quotafile */
1283static ssize_t ext2_quota_write(struct super_block *sb, int type,
1284 const char *data, size_t len, loff_t off)
1285{
1286 struct inode *inode = sb_dqopt(sb)->files[type];
1287 sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1288 int err = 0;
1289 int offset = off & (sb->s_blocksize - 1);
1290 int tocopy;
1291 size_t towrite = len;
1292 struct buffer_head tmp_bh;
1293 struct buffer_head *bh;
1294
5c81a419 1295 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1da177e4
LT		 1296 while (towrite > 0) {
1297 tocopy = sb->s_blocksize - offset < towrite ?
1298 sb->s_blocksize - offset : towrite;
1299
1300 tmp_bh.b_state = 0;
1301 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1302 if (err)
1303 goto out;
1304 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1305 bh = sb_bread(sb, tmp_bh.b_blocknr);
1306 else
1307 bh = sb_getblk(sb, tmp_bh.b_blocknr);
1308 if (!bh) {
1309 err = -EIO;
1310 goto out;
1311 }
1312 lock_buffer(bh);
1313 memcpy(bh->b_data+offset, data, tocopy);
1314 flush_dcache_page(bh->b_page);
1315 set_buffer_uptodate(bh);
1316 mark_buffer_dirty(bh);
1317 unlock_buffer(bh);
1318 brelse(bh);
1319 offset = 0;
1320 towrite -= tocopy;
1321 data += tocopy;
1322 blk++;
1323 }
1324out:
1325 if (len == towrite)
1326 return err;
1327 if (inode->i_size < off+len-towrite)
1328 i_size_write(inode, off+len-towrite);
1329 inode->i_version++;
1330 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1331 mark_inode_dirty(inode);
1b1dcc1b 1332 mutex_unlock(&inode->i_mutex);
1da177e4
LT		 1333 return len - towrite;
1334}
1335
1336#endif
1337
1338static struct file_system_type ext2_fs_type = {
1339 .owner = THIS_MODULE,
1340 .name = "ext2",
1341 .get_sb = ext2_get_sb,
1342 .kill_sb = kill_block_super,
1343 .fs_flags = FS_REQUIRES_DEV,
1344};
1345
1346static int __init init_ext2_fs(void)
1347{
1348 int err = init_ext2_xattr();
1349 if (err)
1350 return err;
1351 err = init_inodecache();
1352 if (err)
1353 goto out1;
1354 err = register_filesystem(&ext2_fs_type);
1355 if (err)
1356 goto out;
1357 return 0;
1358out:
1359 destroy_inodecache();
1360out1:
1361 exit_ext2_xattr();
1362 return err;
1363}
1364
1365static void __exit exit_ext2_fs(void)
1366{
1367 unregister_filesystem(&ext2_fs_type);
1368 destroy_inodecache();
1369 exit_ext2_xattr();
1370}
1371
1372module_init(init_ext2_fs)
1373module_exit(exit_ext2_fs)
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