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mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / affs / super.c
blob789a1c7db5d8cf326635efb526c6699c03a78a8f
1 /*
2 * linux/fs/affs/inode.c
3 *
4 * (c) 1996 Hans-Joachim Widmaier - Rewritten
5 *
6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
7 *
8 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
9 *
10 * (C) 1991 Linus Torvalds - minix filesystem
11 */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/statfs.h>
16 #include <linux/parser.h>
17 #include <linux/magic.h>
18 #include <linux/sched.h>
19 #include <linux/cred.h>
20 #include <linux/slab.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/seq_file.h>
24 #include "affs.h"
25
26 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
27 static int affs_show_options(struct seq_file *m, struct dentry *root);
28 static int affs_remount (struct super_block *sb, int *flags, char *data);
29
30 static void
31 affs_commit_super(struct super_block *sb, int wait)
32 {
33 struct affs_sb_info *sbi = AFFS_SB(sb);
34 struct buffer_head *bh = sbi->s_root_bh;
35 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
36
37 lock_buffer(bh);
38 affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change);
39 affs_fix_checksum(sb, bh);
40 unlock_buffer(bh);
41
42 mark_buffer_dirty(bh);
43 if (wait)
44 sync_dirty_buffer(bh);
45 }
46
47 static void
48 affs_put_super(struct super_block *sb)
49 {
50 struct affs_sb_info *sbi = AFFS_SB(sb);
51 pr_debug("%s()\n", __func__);
52
53 cancel_delayed_work_sync(&sbi->sb_work);
54 }
55
56 static int
57 affs_sync_fs(struct super_block *sb, int wait)
58 {
59 affs_commit_super(sb, wait);
60 return 0;
61 }
62
63 static void flush_superblock(struct work_struct *work)
64 {
65 struct affs_sb_info *sbi;
66 struct super_block *sb;
67
68 sbi = container_of(work, struct affs_sb_info, sb_work.work);
69 sb = sbi->sb;
70
71 spin_lock(&sbi->work_lock);
72 sbi->work_queued = 0;
73 spin_unlock(&sbi->work_lock);
74
75 affs_commit_super(sb, 1);
76 }
77
78 void affs_mark_sb_dirty(struct super_block *sb)
79 {
80 struct affs_sb_info *sbi = AFFS_SB(sb);
81 unsigned long delay;
82
83 if (sb_rdonly(sb))
84 return;
85
86 spin_lock(&sbi->work_lock);
87 if (!sbi->work_queued) {
88 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
89 queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
90 sbi->work_queued = 1;
91 }
92 spin_unlock(&sbi->work_lock);
93 }
94
95 static struct kmem_cache * affs_inode_cachep;
96
97 static struct inode *affs_alloc_inode(struct super_block *sb)
98 {
99 struct affs_inode_info *i;
100
101 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
102 if (!i)
103 return NULL;
104
105 i->vfs_inode.i_version = 1;
106 i->i_lc = NULL;
107 i->i_ext_bh = NULL;
108 i->i_pa_cnt = 0;
109
110 return &i->vfs_inode;
111 }
112
113 static void affs_i_callback(struct rcu_head *head)
114 {
115 struct inode *inode = container_of(head, struct inode, i_rcu);
116 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
117 }
118
119 static void affs_destroy_inode(struct inode *inode)
120 {
121 call_rcu(&inode->i_rcu, affs_i_callback);
122 }
123
124 static void init_once(void *foo)
125 {
126 struct affs_inode_info *ei = (struct affs_inode_info *) foo;
127
128 sema_init(&ei->i_link_lock, 1);
129 sema_init(&ei->i_ext_lock, 1);
130 inode_init_once(&ei->vfs_inode);
131 }
132
133 static int __init init_inodecache(void)
134 {
135 affs_inode_cachep = kmem_cache_create("affs_inode_cache",
136 sizeof(struct affs_inode_info),
137 0, (SLAB_RECLAIM_ACCOUNT|
138 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
139 init_once);
140 if (affs_inode_cachep == NULL)
141 return -ENOMEM;
142 return 0;
143 }
144
145 static void destroy_inodecache(void)
146 {
147 /*
148 * Make sure all delayed rcu free inodes are flushed before we
149 * destroy cache.
150 */
151 rcu_barrier();
152 kmem_cache_destroy(affs_inode_cachep);
153 }
154
155 static const struct super_operations affs_sops = {
156 .alloc_inode = affs_alloc_inode,
157 .destroy_inode = affs_destroy_inode,
158 .write_inode = affs_write_inode,
159 .evict_inode = affs_evict_inode,
160 .put_super = affs_put_super,
161 .sync_fs = affs_sync_fs,
162 .statfs = affs_statfs,
163 .remount_fs = affs_remount,
164 .show_options = affs_show_options,
165 };
166
167 enum {
168 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
169 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
170 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
171 };
172
173 static const match_table_t tokens = {
174 {Opt_bs, "bs=%u"},
175 {Opt_mode, "mode=%o"},
176 {Opt_mufs, "mufs"},
177 {Opt_notruncate, "nofilenametruncate"},
178 {Opt_prefix, "prefix=%s"},
179 {Opt_protect, "protect"},
180 {Opt_reserved, "reserved=%u"},
181 {Opt_root, "root=%u"},
182 {Opt_setgid, "setgid=%u"},
183 {Opt_setuid, "setuid=%u"},
184 {Opt_verbose, "verbose"},
185 {Opt_volume, "volume=%s"},
186 {Opt_ignore, "grpquota"},
187 {Opt_ignore, "noquota"},
188 {Opt_ignore, "quota"},
189 {Opt_ignore, "usrquota"},
190 {Opt_err, NULL},
191 };
192
193 static int
194 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
195 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
196 {
197 char *p;
198 substring_t args[MAX_OPT_ARGS];
199
200 /* Fill in defaults */
201
202 *uid = current_uid();
203 *gid = current_gid();
204 *reserved = 2;
205 *root = -1;
206 *blocksize = -1;
207 volume[0] = ':';
208 volume[1] = 0;
209 *mount_opts = 0;
210 if (!options)
211 return 1;
212
213 while ((p = strsep(&options, ",")) != NULL) {
214 int token, n, option;
215 if (!*p)
216 continue;
217
218 token = match_token(p, tokens, args);
219 switch (token) {
220 case Opt_bs:
221 if (match_int(&args[0], &n))
222 return 0;
223 if (n != 512 && n != 1024 && n != 2048
224 && n != 4096) {
225 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
226 return 0;
227 }
228 *blocksize = n;
229 break;
230 case Opt_mode:
231 if (match_octal(&args[0], &option))
232 return 0;
233 *mode = option & 0777;
234 affs_set_opt(*mount_opts, SF_SETMODE);
235 break;
236 case Opt_mufs:
237 affs_set_opt(*mount_opts, SF_MUFS);
238 break;
239 case Opt_notruncate:
240 affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
241 break;
242 case Opt_prefix:
243 *prefix = match_strdup(&args[0]);
244 if (!*prefix)
245 return 0;
246 affs_set_opt(*mount_opts, SF_PREFIX);
247 break;
248 case Opt_protect:
249 affs_set_opt(*mount_opts, SF_IMMUTABLE);
250 break;
251 case Opt_reserved:
252 if (match_int(&args[0], reserved))
253 return 0;
254 break;
255 case Opt_root:
256 if (match_int(&args[0], root))
257 return 0;
258 break;
259 case Opt_setgid:
260 if (match_int(&args[0], &option))
261 return 0;
262 *gid = make_kgid(current_user_ns(), option);
263 if (!gid_valid(*gid))
264 return 0;
265 affs_set_opt(*mount_opts, SF_SETGID);
266 break;
267 case Opt_setuid:
268 if (match_int(&args[0], &option))
269 return 0;
270 *uid = make_kuid(current_user_ns(), option);
271 if (!uid_valid(*uid))
272 return 0;
273 affs_set_opt(*mount_opts, SF_SETUID);
274 break;
275 case Opt_verbose:
276 affs_set_opt(*mount_opts, SF_VERBOSE);
277 break;
278 case Opt_volume: {
279 char *vol = match_strdup(&args[0]);
280 if (!vol)
281 return 0;
282 strlcpy(volume, vol, 32);
283 kfree(vol);
284 break;
285 }
286 case Opt_ignore:
287 /* Silently ignore the quota options */
288 break;
289 default:
290 pr_warn("Unrecognized mount option \"%s\" or missing value\n",
291 p);
292 return 0;
293 }
294 }
295 return 1;
296 }
297
298 static int affs_show_options(struct seq_file *m, struct dentry *root)
299 {
300 struct super_block *sb = root->d_sb;
301 struct affs_sb_info *sbi = AFFS_SB(sb);
302
303 if (sb->s_blocksize)
304 seq_printf(m, ",bs=%lu", sb->s_blocksize);
305 if (affs_test_opt(sbi->s_flags, SF_SETMODE))
306 seq_printf(m, ",mode=%o", sbi->s_mode);
307 if (affs_test_opt(sbi->s_flags, SF_MUFS))
308 seq_puts(m, ",mufs");
309 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
310 seq_puts(m, ",nofilenametruncate");
311 if (affs_test_opt(sbi->s_flags, SF_PREFIX))
312 seq_printf(m, ",prefix=%s", sbi->s_prefix);
313 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
314 seq_puts(m, ",protect");
315 if (sbi->s_reserved != 2)
316 seq_printf(m, ",reserved=%u", sbi->s_reserved);
317 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
318 seq_printf(m, ",root=%u", sbi->s_root_block);
319 if (affs_test_opt(sbi->s_flags, SF_SETGID))
320 seq_printf(m, ",setgid=%u",
321 from_kgid_munged(&init_user_ns, sbi->s_gid));
322 if (affs_test_opt(sbi->s_flags, SF_SETUID))
323 seq_printf(m, ",setuid=%u",
324 from_kuid_munged(&init_user_ns, sbi->s_uid));
325 if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
326 seq_puts(m, ",verbose");
327 if (sbi->s_volume[0])
328 seq_printf(m, ",volume=%s", sbi->s_volume);
329 return 0;
330 }
331
332 /* This function definitely needs to be split up. Some fine day I'll
333 * hopefully have the guts to do so. Until then: sorry for the mess.
334 */
335
336 static int affs_fill_super(struct super_block *sb, void *data, int silent)
337 {
338 struct affs_sb_info *sbi;
339 struct buffer_head *root_bh = NULL;
340 struct buffer_head *boot_bh;
341 struct inode *root_inode = NULL;
342 s32 root_block;
343 int size, blocksize;
344 u32 chksum;
345 int num_bm;
346 int i, j;
347 kuid_t uid;
348 kgid_t gid;
349 int reserved;
350 unsigned long mount_flags;
351 int tmp_flags; /* fix remount prototype... */
352 u8 sig[4];
353 int ret;
354
355 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
356
357 sb->s_magic = AFFS_SUPER_MAGIC;
358 sb->s_op = &affs_sops;
359 sb->s_flags |= MS_NODIRATIME;
360
361 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
362 if (!sbi)
363 return -ENOMEM;
364
365 sb->s_fs_info = sbi;
366 sbi->sb = sb;
367 mutex_init(&sbi->s_bmlock);
368 spin_lock_init(&sbi->symlink_lock);
369 spin_lock_init(&sbi->work_lock);
370 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
371
372 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
373 &blocksize,&sbi->s_prefix,
374 sbi->s_volume, &mount_flags)) {
375 pr_err("Error parsing options\n");
376 return -EINVAL;
377 }
378 /* N.B. after this point s_prefix must be released */
379
380 sbi->s_flags = mount_flags;
381 sbi->s_mode = i;
382 sbi->s_uid = uid;
383 sbi->s_gid = gid;
384 sbi->s_reserved= reserved;
385
386 /* Get the size of the device in 512-byte blocks.
387 * If we later see that the partition uses bigger
388 * blocks, we will have to change it.
389 */
390
391 size = i_size_read(sb->s_bdev->bd_inode) >> 9;
392 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
393
394 affs_set_blocksize(sb, PAGE_SIZE);
395 /* Try to find root block. Its location depends on the block size. */
396
397 i = bdev_logical_block_size(sb->s_bdev);
398 j = PAGE_SIZE;
399 if (blocksize > 0) {
400 i = j = blocksize;
401 size = size / (blocksize / 512);
402 }
403
404 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
405 sbi->s_root_block = root_block;
406 if (root_block < 0)
407 sbi->s_root_block = (reserved + size - 1) / 2;
408 pr_debug("setting blocksize to %d\n", blocksize);
409 affs_set_blocksize(sb, blocksize);
410 sbi->s_partition_size = size;
411
412 /* The root block location that was calculated above is not
413 * correct if the partition size is an odd number of 512-
414 * byte blocks, which will be rounded down to a number of
415 * 1024-byte blocks, and if there were an even number of
416 * reserved blocks. Ideally, all partition checkers should
417 * report the real number of blocks of the real blocksize,
418 * but since this just cannot be done, we have to try to
419 * find the root block anyways. In the above case, it is one
420 * block behind the calculated one. So we check this one, too.
421 */
422 for (num_bm = 0; num_bm < 2; num_bm++) {
423 pr_debug("Dev %s, trying root=%u, bs=%d, "
424 "size=%d, reserved=%d\n",
425 sb->s_id,
426 sbi->s_root_block + num_bm,
427 blocksize, size, reserved);
428 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
429 if (!root_bh)
430 continue;
431 if (!affs_checksum_block(sb, root_bh) &&
432 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
433 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
434 sbi->s_hashsize = blocksize / 4 - 56;
435 sbi->s_root_block += num_bm;
436 goto got_root;
437 }
438 affs_brelse(root_bh);
439 root_bh = NULL;
440 }
441 }
442 if (!silent)
443 pr_err("No valid root block on device %s\n", sb->s_id);
444 return -EINVAL;
445
446 /* N.B. after this point bh must be released */
447 got_root:
448 /* Keep super block in cache */
449 sbi->s_root_bh = root_bh;
450 root_block = sbi->s_root_block;
451
452 /* Find out which kind of FS we have */
453 boot_bh = sb_bread(sb, 0);
454 if (!boot_bh) {
455 pr_err("Cannot read boot block\n");
456 return -EINVAL;
457 }
458 memcpy(sig, boot_bh->b_data, 4);
459 brelse(boot_bh);
460 chksum = be32_to_cpu(*(__be32 *)sig);
461
462 /* Dircache filesystems are compatible with non-dircache ones
463 * when reading. As long as they aren't supported, writing is
464 * not recommended.
465 */
466 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
467 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) {
468 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
469 sb->s_flags |= MS_RDONLY;
470 }
471 switch (chksum) {
472 case MUFS_FS:
473 case MUFS_INTLFFS:
474 case MUFS_DCFFS:
475 affs_set_opt(sbi->s_flags, SF_MUFS);
476 /* fall thru */
477 case FS_INTLFFS:
478 case FS_DCFFS:
479 affs_set_opt(sbi->s_flags, SF_INTL);
480 break;
481 case MUFS_FFS:
482 affs_set_opt(sbi->s_flags, SF_MUFS);
483 break;
484 case FS_FFS:
485 break;
486 case MUFS_OFS:
487 affs_set_opt(sbi->s_flags, SF_MUFS);
488 /* fall thru */
489 case FS_OFS:
490 affs_set_opt(sbi->s_flags, SF_OFS);
491 sb->s_flags |= MS_NOEXEC;
492 break;
493 case MUFS_DCOFS:
494 case MUFS_INTLOFS:
495 affs_set_opt(sbi->s_flags, SF_MUFS);
496 case FS_DCOFS:
497 case FS_INTLOFS:
498 affs_set_opt(sbi->s_flags, SF_INTL);
499 affs_set_opt(sbi->s_flags, SF_OFS);
500 sb->s_flags |= MS_NOEXEC;
501 break;
502 default:
503 pr_err("Unknown filesystem on device %s: %08X\n",
504 sb->s_id, chksum);
505 return -EINVAL;
506 }
507
508 if (affs_test_opt(mount_flags, SF_VERBOSE)) {
509 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
510 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
511 len > 31 ? 31 : len,
512 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
513 sig, sig[3] + '0', blocksize);
514 }
515
516 sb->s_flags |= MS_NODEV | MS_NOSUID;
517
518 sbi->s_data_blksize = sb->s_blocksize;
519 if (affs_test_opt(sbi->s_flags, SF_OFS))
520 sbi->s_data_blksize -= 24;
521
522 tmp_flags = sb->s_flags;
523 ret = affs_init_bitmap(sb, &tmp_flags);
524 if (ret)
525 return ret;
526 sb->s_flags = tmp_flags;
527
528 /* set up enough so that it can read an inode */
529
530 root_inode = affs_iget(sb, root_block);
531 if (IS_ERR(root_inode))
532 return PTR_ERR(root_inode);
533
534 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
535 sb->s_d_op = &affs_intl_dentry_operations;
536 else
537 sb->s_d_op = &affs_dentry_operations;
538
539 sb->s_root = d_make_root(root_inode);
540 if (!sb->s_root) {
541 pr_err("AFFS: Get root inode failed\n");
542 return -ENOMEM;
543 }
544
545 sb->s_export_op = &affs_export_ops;
546 pr_debug("s_flags=%lX\n", sb->s_flags);
547 return 0;
548 }
549
550 static int
551 affs_remount(struct super_block *sb, int *flags, char *data)
552 {
553 struct affs_sb_info *sbi = AFFS_SB(sb);
554 int blocksize;
555 kuid_t uid;
556 kgid_t gid;
557 int mode;
558 int reserved;
559 int root_block;
560 unsigned long mount_flags;
561 int res = 0;
562 char volume[32];
563 char *prefix = NULL;
564
565 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
566
567 sync_filesystem(sb);
568 *flags |= MS_NODIRATIME;
569
570 memcpy(volume, sbi->s_volume, 32);
571 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
572 &blocksize, &prefix, volume,
573 &mount_flags)) {
574 kfree(prefix);
575 return -EINVAL;
576 }
577
578 flush_delayed_work(&sbi->sb_work);
579
580 sbi->s_flags = mount_flags;
581 sbi->s_mode = mode;
582 sbi->s_uid = uid;
583 sbi->s_gid = gid;
584 /* protect against readers */
585 spin_lock(&sbi->symlink_lock);
586 if (prefix) {
587 kfree(sbi->s_prefix);
588 sbi->s_prefix = prefix;
589 }
590 memcpy(sbi->s_volume, volume, 32);
591 spin_unlock(&sbi->symlink_lock);
592
593 if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb))
594 return 0;
595
596 if (*flags & MS_RDONLY)
597 affs_free_bitmap(sb);
598 else
599 res = affs_init_bitmap(sb, flags);
600
601 return res;
602 }
603
604 static int
605 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
606 {
607 struct super_block *sb = dentry->d_sb;
608 int free;
609 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
610
611 pr_debug("%s() partsize=%d, reserved=%d\n",
612 __func__, AFFS_SB(sb)->s_partition_size,
613 AFFS_SB(sb)->s_reserved);
614
615 free = affs_count_free_blocks(sb);
616 buf->f_type = AFFS_SUPER_MAGIC;
617 buf->f_bsize = sb->s_blocksize;
618 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
619 buf->f_bfree = free;
620 buf->f_bavail = free;
621 buf->f_fsid.val[0] = (u32)id;
622 buf->f_fsid.val[1] = (u32)(id >> 32);
623 buf->f_namelen = AFFSNAMEMAX;
624 return 0;
625 }
626
627 static struct dentry *affs_mount(struct file_system_type *fs_type,
628 int flags, const char *dev_name, void *data)
629 {
630 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
631 }
632
633 static void affs_kill_sb(struct super_block *sb)
634 {
635 struct affs_sb_info *sbi = AFFS_SB(sb);
636 kill_block_super(sb);
637 if (sbi) {
638 affs_free_bitmap(sb);
639 affs_brelse(sbi->s_root_bh);
640 kfree(sbi->s_prefix);
641 mutex_destroy(&sbi->s_bmlock);
642 kfree(sbi);
643 }
644 }
645
646 static struct file_system_type affs_fs_type = {
647 .owner = THIS_MODULE,
648 .name = "affs",
649 .mount = affs_mount,
650 .kill_sb = affs_kill_sb,
651 .fs_flags = FS_REQUIRES_DEV,
652 };
653 MODULE_ALIAS_FS("affs");
654
655 static int __init init_affs_fs(void)
656 {
657 int err = init_inodecache();
658 if (err)
659 goto out1;
660 err = register_filesystem(&affs_fs_type);
661 if (err)
662 goto out;
663 return 0;
664 out:
665 destroy_inodecache();
666 out1:
667 return err;
668 }
669
670 static void __exit exit_affs_fs(void)
671 {
672 unregister_filesystem(&affs_fs_type);
673 destroy_inodecache();
674 }
675
676 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
677 MODULE_LICENSE("GPL");
678
679 module_init(init_affs_fs)
680 module_exit(exit_affs_fs)
Linux with added FPC-III support