b43legacy: avoid PPC fault during resume
[linux-2.6/mini2440.git] / fs / reiserfs / xattr.c
blob6925b835a43b6f2f94e8a4217180b2e8d1735ab7
1 /*
2 * linux/fs/reiserfs/xattr.c
4 * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
6 */
8 /*
9 * In order to implement EA/ACLs in a clean, backwards compatible manner,
10 * they are implemented as files in a "private" directory.
11 * Each EA is in it's own file, with the directory layout like so (/ is assumed
12 * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
13 * directories named using the capital-hex form of the objectid and
14 * generation number are used. Inside each directory are individual files
15 * named with the name of the extended attribute.
17 * So, for objectid 12648430, we could have:
18 * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
19 * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
20 * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
21 * .. or similar.
23 * The file contents are the text of the EA. The size is known based on the
24 * stat data describing the file.
26 * In the case of system.posix_acl_access and system.posix_acl_default, since
27 * these are special cases for filesystem ACLs, they are interpreted by the
28 * kernel, in addition, they are negatively and positively cached and attached
29 * to the inode so that unnecessary lookups are avoided.
31 * Locking works like so:
32 * Directory components (xattr root, xattr dir) are protectd by their i_mutex.
33 * The xattrs themselves are protected by the xattr_sem.
36 #include <linux/reiserfs_fs.h>
37 #include <linux/capability.h>
38 #include <linux/dcache.h>
39 #include <linux/namei.h>
40 #include <linux/errno.h>
41 #include <linux/fs.h>
42 #include <linux/file.h>
43 #include <linux/pagemap.h>
44 #include <linux/xattr.h>
45 #include <linux/reiserfs_xattr.h>
46 #include <linux/reiserfs_acl.h>
47 #include <asm/uaccess.h>
48 #include <net/checksum.h>
49 #include <linux/stat.h>
50 #include <linux/quotaops.h>
52 #define PRIVROOT_NAME ".reiserfs_priv"
53 #define XAROOT_NAME "xattrs"
56 /* Helpers for inode ops. We do this so that we don't have all the VFS
57 * overhead and also for proper i_mutex annotation.
58 * dir->i_mutex must be held for all of them. */
59 #ifdef CONFIG_REISERFS_FS_XATTR
60 static int xattr_create(struct inode *dir, struct dentry *dentry, int mode)
62 BUG_ON(!mutex_is_locked(&dir->i_mutex));
63 vfs_dq_init(dir);
64 return dir->i_op->create(dir, dentry, mode, NULL);
66 #endif
68 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode)
70 BUG_ON(!mutex_is_locked(&dir->i_mutex));
71 vfs_dq_init(dir);
72 return dir->i_op->mkdir(dir, dentry, mode);
75 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
76 * mutation ops aren't called during rename or splace, which are the
77 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
78 * better than allocating another subclass just for this code. */
79 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
81 int error;
82 BUG_ON(!mutex_is_locked(&dir->i_mutex));
83 vfs_dq_init(dir);
85 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
86 error = dir->i_op->unlink(dir, dentry);
87 mutex_unlock(&dentry->d_inode->i_mutex);
89 if (!error)
90 d_delete(dentry);
91 return error;
94 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
96 int error;
97 BUG_ON(!mutex_is_locked(&dir->i_mutex));
98 vfs_dq_init(dir);
100 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
101 dentry_unhash(dentry);
102 error = dir->i_op->rmdir(dir, dentry);
103 if (!error)
104 dentry->d_inode->i_flags |= S_DEAD;
105 mutex_unlock(&dentry->d_inode->i_mutex);
106 if (!error)
107 d_delete(dentry);
108 dput(dentry);
110 return error;
113 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
115 static struct dentry *open_xa_root(struct super_block *sb, int flags)
117 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
118 struct dentry *xaroot;
119 if (!privroot->d_inode)
120 return ERR_PTR(-ENODATA);
122 mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
124 xaroot = dget(REISERFS_SB(sb)->xattr_root);
125 if (!xaroot)
126 xaroot = ERR_PTR(-ENODATA);
127 else if (!xaroot->d_inode) {
128 int err = -ENODATA;
129 if (xattr_may_create(flags))
130 err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
131 if (err) {
132 dput(xaroot);
133 xaroot = ERR_PTR(err);
137 mutex_unlock(&privroot->d_inode->i_mutex);
138 return xaroot;
141 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
143 struct dentry *xaroot, *xadir;
144 char namebuf[17];
146 xaroot = open_xa_root(inode->i_sb, flags);
147 if (IS_ERR(xaroot))
148 return xaroot;
150 snprintf(namebuf, sizeof(namebuf), "%X.%X",
151 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
152 inode->i_generation);
154 mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
156 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
157 if (!IS_ERR(xadir) && !xadir->d_inode) {
158 int err = -ENODATA;
159 if (xattr_may_create(flags))
160 err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
161 if (err) {
162 dput(xadir);
163 xadir = ERR_PTR(err);
167 mutex_unlock(&xaroot->d_inode->i_mutex);
168 dput(xaroot);
169 return xadir;
172 /* The following are side effects of other operations that aren't explicitly
173 * modifying extended attributes. This includes operations such as permissions
174 * or ownership changes, object deletions, etc. */
175 struct reiserfs_dentry_buf {
176 struct dentry *xadir;
177 int count;
178 struct dentry *dentries[8];
181 static int
182 fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
183 u64 ino, unsigned int d_type)
185 struct reiserfs_dentry_buf *dbuf = buf;
186 struct dentry *dentry;
187 WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
189 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
190 return -ENOSPC;
192 if (name[0] == '.' && (name[1] == '\0' ||
193 (name[1] == '.' && name[2] == '\0')))
194 return 0;
196 dentry = lookup_one_len(name, dbuf->xadir, namelen);
197 if (IS_ERR(dentry)) {
198 return PTR_ERR(dentry);
199 } else if (!dentry->d_inode) {
200 /* A directory entry exists, but no file? */
201 reiserfs_error(dentry->d_sb, "xattr-20003",
202 "Corrupted directory: xattr %s listed but "
203 "not found for file %s.\n",
204 dentry->d_name.name, dbuf->xadir->d_name.name);
205 dput(dentry);
206 return -EIO;
209 dbuf->dentries[dbuf->count++] = dentry;
210 return 0;
213 static void
214 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
216 int i;
217 for (i = 0; i < buf->count; i++)
218 if (buf->dentries[i])
219 dput(buf->dentries[i]);
222 static int reiserfs_for_each_xattr(struct inode *inode,
223 int (*action)(struct dentry *, void *),
224 void *data)
226 struct dentry *dir;
227 int i, err = 0;
228 loff_t pos = 0;
229 struct reiserfs_dentry_buf buf = {
230 .count = 0,
233 /* Skip out, an xattr has no xattrs associated with it */
234 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
235 return 0;
237 dir = open_xa_dir(inode, XATTR_REPLACE);
238 if (IS_ERR(dir)) {
239 err = PTR_ERR(dir);
240 goto out;
241 } else if (!dir->d_inode) {
242 err = 0;
243 goto out_dir;
246 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
247 buf.xadir = dir;
248 err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos);
249 while ((err == 0 || err == -ENOSPC) && buf.count) {
250 err = 0;
252 for (i = 0; i < buf.count && buf.dentries[i]; i++) {
253 int lerr = 0;
254 struct dentry *dentry = buf.dentries[i];
256 if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode))
257 lerr = action(dentry, data);
259 dput(dentry);
260 buf.dentries[i] = NULL;
261 err = lerr ?: err;
263 buf.count = 0;
264 if (!err)
265 err = reiserfs_readdir_dentry(dir, &buf,
266 fill_with_dentries, &pos);
268 mutex_unlock(&dir->d_inode->i_mutex);
270 /* Clean up after a failed readdir */
271 cleanup_dentry_buf(&buf);
273 if (!err) {
274 /* We start a transaction here to avoid a ABBA situation
275 * between the xattr root's i_mutex and the journal lock.
276 * This doesn't incur much additional overhead since the
277 * new transaction will just nest inside the
278 * outer transaction. */
279 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
280 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
281 struct reiserfs_transaction_handle th;
282 err = journal_begin(&th, inode->i_sb, blocks);
283 if (!err) {
284 int jerror;
285 mutex_lock_nested(&dir->d_parent->d_inode->i_mutex,
286 I_MUTEX_XATTR);
287 err = action(dir, data);
288 jerror = journal_end(&th, inode->i_sb, blocks);
289 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
290 err = jerror ?: err;
293 out_dir:
294 dput(dir);
295 out:
296 /* -ENODATA isn't an error */
297 if (err == -ENODATA)
298 err = 0;
299 return err;
302 static int delete_one_xattr(struct dentry *dentry, void *data)
304 struct inode *dir = dentry->d_parent->d_inode;
306 /* This is the xattr dir, handle specially. */
307 if (S_ISDIR(dentry->d_inode->i_mode))
308 return xattr_rmdir(dir, dentry);
310 return xattr_unlink(dir, dentry);
313 static int chown_one_xattr(struct dentry *dentry, void *data)
315 struct iattr *attrs = data;
316 return reiserfs_setattr(dentry, attrs);
319 /* No i_mutex, but the inode is unconnected. */
320 int reiserfs_delete_xattrs(struct inode *inode)
322 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
323 if (err)
324 reiserfs_warning(inode->i_sb, "jdm-20004",
325 "Couldn't delete all xattrs (%d)\n", err);
326 return err;
329 /* inode->i_mutex: down */
330 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
332 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
333 if (err)
334 reiserfs_warning(inode->i_sb, "jdm-20007",
335 "Couldn't chown all xattrs (%d)\n", err);
336 return err;
339 #ifdef CONFIG_REISERFS_FS_XATTR
340 /* Returns a dentry corresponding to a specific extended attribute file
341 * for the inode. If flags allow, the file is created. Otherwise, a
342 * valid or negative dentry, or an error is returned. */
343 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
344 int flags)
346 struct dentry *xadir, *xafile;
347 int err = 0;
349 xadir = open_xa_dir(inode, flags);
350 if (IS_ERR(xadir))
351 return ERR_CAST(xadir);
353 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
354 xafile = lookup_one_len(name, xadir, strlen(name));
355 if (IS_ERR(xafile)) {
356 err = PTR_ERR(xafile);
357 goto out;
360 if (xafile->d_inode && (flags & XATTR_CREATE))
361 err = -EEXIST;
363 if (!xafile->d_inode) {
364 err = -ENODATA;
365 if (xattr_may_create(flags))
366 err = xattr_create(xadir->d_inode, xafile,
367 0700|S_IFREG);
370 if (err)
371 dput(xafile);
372 out:
373 mutex_unlock(&xadir->d_inode->i_mutex);
374 dput(xadir);
375 if (err)
376 return ERR_PTR(err);
377 return xafile;
380 /* Internal operations on file data */
381 static inline void reiserfs_put_page(struct page *page)
383 kunmap(page);
384 page_cache_release(page);
387 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
389 struct address_space *mapping = dir->i_mapping;
390 struct page *page;
391 /* We can deadlock if we try to free dentries,
392 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
393 mapping_set_gfp_mask(mapping, GFP_NOFS);
394 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
395 if (!IS_ERR(page)) {
396 kmap(page);
397 if (PageError(page))
398 goto fail;
400 return page;
402 fail:
403 reiserfs_put_page(page);
404 return ERR_PTR(-EIO);
407 static inline __u32 xattr_hash(const char *msg, int len)
409 return csum_partial(msg, len, 0);
412 int reiserfs_commit_write(struct file *f, struct page *page,
413 unsigned from, unsigned to);
414 int reiserfs_prepare_write(struct file *f, struct page *page,
415 unsigned from, unsigned to);
417 static void update_ctime(struct inode *inode)
419 struct timespec now = current_fs_time(inode->i_sb);
420 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
421 timespec_equal(&inode->i_ctime, &now))
422 return;
424 inode->i_ctime = CURRENT_TIME_SEC;
425 mark_inode_dirty(inode);
428 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
430 int err = 0;
431 struct dentry *dentry, *xadir;
433 xadir = open_xa_dir(inode, XATTR_REPLACE);
434 if (IS_ERR(xadir))
435 return PTR_ERR(xadir);
437 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
438 dentry = lookup_one_len(name, xadir, strlen(name));
439 if (IS_ERR(dentry)) {
440 err = PTR_ERR(dentry);
441 goto out_dput;
444 if (dentry->d_inode) {
445 err = xattr_unlink(xadir->d_inode, dentry);
446 update_ctime(inode);
449 dput(dentry);
450 out_dput:
451 mutex_unlock(&xadir->d_inode->i_mutex);
452 dput(xadir);
453 return err;
457 /* Generic extended attribute operations that can be used by xa plugins */
460 * inode->i_mutex: down
463 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
464 struct inode *inode, const char *name,
465 const void *buffer, size_t buffer_size, int flags)
467 int err = 0;
468 struct dentry *dentry;
469 struct page *page;
470 char *data;
471 size_t file_pos = 0;
472 size_t buffer_pos = 0;
473 size_t new_size;
474 __u32 xahash = 0;
476 if (get_inode_sd_version(inode) == STAT_DATA_V1)
477 return -EOPNOTSUPP;
479 if (!buffer)
480 return lookup_and_delete_xattr(inode, name);
482 dentry = xattr_lookup(inode, name, flags);
483 if (IS_ERR(dentry))
484 return PTR_ERR(dentry);
486 down_write(&REISERFS_I(inode)->i_xattr_sem);
488 xahash = xattr_hash(buffer, buffer_size);
489 while (buffer_pos < buffer_size || buffer_pos == 0) {
490 size_t chunk;
491 size_t skip = 0;
492 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
493 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
494 chunk = PAGE_CACHE_SIZE;
495 else
496 chunk = buffer_size - buffer_pos;
498 page = reiserfs_get_page(dentry->d_inode, file_pos);
499 if (IS_ERR(page)) {
500 err = PTR_ERR(page);
501 goto out_unlock;
504 lock_page(page);
505 data = page_address(page);
507 if (file_pos == 0) {
508 struct reiserfs_xattr_header *rxh;
509 skip = file_pos = sizeof(struct reiserfs_xattr_header);
510 if (chunk + skip > PAGE_CACHE_SIZE)
511 chunk = PAGE_CACHE_SIZE - skip;
512 rxh = (struct reiserfs_xattr_header *)data;
513 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
514 rxh->h_hash = cpu_to_le32(xahash);
517 err = reiserfs_prepare_write(NULL, page, page_offset,
518 page_offset + chunk + skip);
519 if (!err) {
520 if (buffer)
521 memcpy(data + skip, buffer + buffer_pos, chunk);
522 err = reiserfs_commit_write(NULL, page, page_offset,
523 page_offset + chunk +
524 skip);
526 unlock_page(page);
527 reiserfs_put_page(page);
528 buffer_pos += chunk;
529 file_pos += chunk;
530 skip = 0;
531 if (err || buffer_size == 0 || !buffer)
532 break;
535 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
536 if (!err && new_size < i_size_read(dentry->d_inode)) {
537 struct iattr newattrs = {
538 .ia_ctime = current_fs_time(inode->i_sb),
539 .ia_size = buffer_size,
540 .ia_valid = ATTR_SIZE | ATTR_CTIME,
542 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
543 down_write(&dentry->d_inode->i_alloc_sem);
544 err = reiserfs_setattr(dentry, &newattrs);
545 up_write(&dentry->d_inode->i_alloc_sem);
546 mutex_unlock(&dentry->d_inode->i_mutex);
547 } else
548 update_ctime(inode);
549 out_unlock:
550 up_write(&REISERFS_I(inode)->i_xattr_sem);
551 dput(dentry);
552 return err;
555 /* We need to start a transaction to maintain lock ordering */
556 int reiserfs_xattr_set(struct inode *inode, const char *name,
557 const void *buffer, size_t buffer_size, int flags)
560 struct reiserfs_transaction_handle th;
561 int error, error2;
562 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
564 if (!(flags & XATTR_REPLACE))
565 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
567 reiserfs_write_lock(inode->i_sb);
568 error = journal_begin(&th, inode->i_sb, jbegin_count);
569 if (error) {
570 reiserfs_write_unlock(inode->i_sb);
571 return error;
574 error = reiserfs_xattr_set_handle(&th, inode, name,
575 buffer, buffer_size, flags);
577 error2 = journal_end(&th, inode->i_sb, jbegin_count);
578 if (error == 0)
579 error = error2;
580 reiserfs_write_unlock(inode->i_sb);
582 return error;
586 * inode->i_mutex: down
589 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
590 size_t buffer_size)
592 ssize_t err = 0;
593 struct dentry *dentry;
594 size_t isize;
595 size_t file_pos = 0;
596 size_t buffer_pos = 0;
597 struct page *page;
598 __u32 hash = 0;
600 if (name == NULL)
601 return -EINVAL;
603 /* We can't have xattrs attached to v1 items since they don't have
604 * generation numbers */
605 if (get_inode_sd_version(inode) == STAT_DATA_V1)
606 return -EOPNOTSUPP;
608 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
609 if (IS_ERR(dentry)) {
610 err = PTR_ERR(dentry);
611 goto out;
614 down_read(&REISERFS_I(inode)->i_xattr_sem);
616 isize = i_size_read(dentry->d_inode);
618 /* Just return the size needed */
619 if (buffer == NULL) {
620 err = isize - sizeof(struct reiserfs_xattr_header);
621 goto out_unlock;
624 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
625 err = -ERANGE;
626 goto out_unlock;
629 while (file_pos < isize) {
630 size_t chunk;
631 char *data;
632 size_t skip = 0;
633 if (isize - file_pos > PAGE_CACHE_SIZE)
634 chunk = PAGE_CACHE_SIZE;
635 else
636 chunk = isize - file_pos;
638 page = reiserfs_get_page(dentry->d_inode, file_pos);
639 if (IS_ERR(page)) {
640 err = PTR_ERR(page);
641 goto out_unlock;
644 lock_page(page);
645 data = page_address(page);
646 if (file_pos == 0) {
647 struct reiserfs_xattr_header *rxh =
648 (struct reiserfs_xattr_header *)data;
649 skip = file_pos = sizeof(struct reiserfs_xattr_header);
650 chunk -= skip;
651 /* Magic doesn't match up.. */
652 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
653 unlock_page(page);
654 reiserfs_put_page(page);
655 reiserfs_warning(inode->i_sb, "jdm-20001",
656 "Invalid magic for xattr (%s) "
657 "associated with %k", name,
658 INODE_PKEY(inode));
659 err = -EIO;
660 goto out_unlock;
662 hash = le32_to_cpu(rxh->h_hash);
664 memcpy(buffer + buffer_pos, data + skip, chunk);
665 unlock_page(page);
666 reiserfs_put_page(page);
667 file_pos += chunk;
668 buffer_pos += chunk;
669 skip = 0;
671 err = isize - sizeof(struct reiserfs_xattr_header);
673 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
674 hash) {
675 reiserfs_warning(inode->i_sb, "jdm-20002",
676 "Invalid hash for xattr (%s) associated "
677 "with %k", name, INODE_PKEY(inode));
678 err = -EIO;
681 out_unlock:
682 up_read(&REISERFS_I(inode)->i_xattr_sem);
683 dput(dentry);
685 out:
686 return err;
690 * In order to implement different sets of xattr operations for each xattr
691 * prefix with the generic xattr API, a filesystem should create a
692 * null-terminated array of struct xattr_handler (one for each prefix) and
693 * hang a pointer to it off of the s_xattr field of the superblock.
695 * The generic_fooxattr() functions will use this list to dispatch xattr
696 * operations to the correct xattr_handler.
698 #define for_each_xattr_handler(handlers, handler) \
699 for ((handler) = *(handlers)++; \
700 (handler) != NULL; \
701 (handler) = *(handlers)++)
703 /* This is the implementation for the xattr plugin infrastructure */
704 static inline struct xattr_handler *
705 find_xattr_handler_prefix(struct xattr_handler **handlers,
706 const char *name)
708 struct xattr_handler *xah;
710 if (!handlers)
711 return NULL;
713 for_each_xattr_handler(handlers, xah) {
714 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
715 break;
718 return xah;
723 * Inode operation getxattr()
725 ssize_t
726 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
727 size_t size)
729 struct inode *inode = dentry->d_inode;
730 struct xattr_handler *handler;
732 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
734 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
735 return -EOPNOTSUPP;
737 return handler->get(inode, name, buffer, size);
741 * Inode operation setxattr()
743 * dentry->d_inode->i_mutex down
746 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
747 size_t size, int flags)
749 struct inode *inode = dentry->d_inode;
750 struct xattr_handler *handler;
752 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
754 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
755 return -EOPNOTSUPP;
757 return handler->set(inode, name, value, size, flags);
761 * Inode operation removexattr()
763 * dentry->d_inode->i_mutex down
765 int reiserfs_removexattr(struct dentry *dentry, const char *name)
767 struct inode *inode = dentry->d_inode;
768 struct xattr_handler *handler;
769 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
771 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
772 return -EOPNOTSUPP;
774 return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
777 struct listxattr_buf {
778 size_t size;
779 size_t pos;
780 char *buf;
781 struct inode *inode;
784 static int listxattr_filler(void *buf, const char *name, int namelen,
785 loff_t offset, u64 ino, unsigned int d_type)
787 struct listxattr_buf *b = (struct listxattr_buf *)buf;
788 size_t size;
789 if (name[0] != '.' ||
790 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
791 struct xattr_handler *handler;
792 handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
793 name);
794 if (!handler) /* Unsupported xattr name */
795 return 0;
796 if (b->buf) {
797 size = handler->list(b->inode, b->buf + b->pos,
798 b->size, name, namelen);
799 if (size > b->size)
800 return -ERANGE;
801 } else {
802 size = handler->list(b->inode, NULL, 0, name, namelen);
805 b->pos += size;
807 return 0;
811 * Inode operation listxattr()
813 * We totally ignore the generic listxattr here because it would be stupid
814 * not to. Since the xattrs are organized in a directory, we can just
815 * readdir to find them.
817 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
819 struct dentry *dir;
820 int err = 0;
821 loff_t pos = 0;
822 struct listxattr_buf buf = {
823 .inode = dentry->d_inode,
824 .buf = buffer,
825 .size = buffer ? size : 0,
828 if (!dentry->d_inode)
829 return -EINVAL;
831 if (!dentry->d_sb->s_xattr ||
832 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
833 return -EOPNOTSUPP;
835 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
836 if (IS_ERR(dir)) {
837 err = PTR_ERR(dir);
838 if (err == -ENODATA)
839 err = 0; /* Not an error if there aren't any xattrs */
840 goto out;
843 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
844 err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos);
845 mutex_unlock(&dir->d_inode->i_mutex);
847 if (!err)
848 err = buf.pos;
850 dput(dir);
851 out:
852 return err;
855 static int reiserfs_check_acl(struct inode *inode, int mask)
857 struct posix_acl *acl;
858 int error = -EAGAIN; /* do regular unix permission checks by default */
860 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
862 if (acl) {
863 if (!IS_ERR(acl)) {
864 error = posix_acl_permission(inode, acl, mask);
865 posix_acl_release(acl);
866 } else if (PTR_ERR(acl) != -ENODATA)
867 error = PTR_ERR(acl);
870 return error;
873 static int create_privroot(struct dentry *dentry)
875 int err;
876 struct inode *inode = dentry->d_parent->d_inode;
877 WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
879 err = xattr_mkdir(inode, dentry, 0700);
880 if (err || !dentry->d_inode) {
881 reiserfs_warning(dentry->d_sb, "jdm-20006",
882 "xattrs/ACLs enabled and couldn't "
883 "find/create .reiserfs_priv. "
884 "Failing mount.");
885 return -EOPNOTSUPP;
888 dentry->d_inode->i_flags |= S_PRIVATE;
889 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
890 "storage.\n", PRIVROOT_NAME);
892 return 0;
895 #else
896 int __init reiserfs_xattr_register_handlers(void) { return 0; }
897 void reiserfs_xattr_unregister_handlers(void) {}
898 static int create_privroot(struct dentry *dentry) { return 0; }
899 #endif
901 /* Actual operations that are exported to VFS-land */
902 struct xattr_handler *reiserfs_xattr_handlers[] = {
903 #ifdef CONFIG_REISERFS_FS_XATTR
904 &reiserfs_xattr_user_handler,
905 &reiserfs_xattr_trusted_handler,
906 #endif
907 #ifdef CONFIG_REISERFS_FS_SECURITY
908 &reiserfs_xattr_security_handler,
909 #endif
910 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
911 &reiserfs_posix_acl_access_handler,
912 &reiserfs_posix_acl_default_handler,
913 #endif
914 NULL
917 static int xattr_mount_check(struct super_block *s)
919 /* We need generation numbers to ensure that the oid mapping is correct
920 * v3.5 filesystems don't have them. */
921 if (old_format_only(s)) {
922 if (reiserfs_xattrs_optional(s)) {
923 /* Old format filesystem, but optional xattrs have
924 * been enabled. Error out. */
925 reiserfs_warning(s, "jdm-2005",
926 "xattrs/ACLs not supported "
927 "on pre-v3.6 format filesystems. "
928 "Failing mount.");
929 return -EOPNOTSUPP;
933 return 0;
936 int reiserfs_permission(struct inode *inode, int mask)
939 * We don't do permission checks on the internal objects.
940 * Permissions are determined by the "owning" object.
942 if (IS_PRIVATE(inode))
943 return 0;
945 #ifdef CONFIG_REISERFS_FS_XATTR
947 * Stat data v1 doesn't support ACLs.
949 if (get_inode_sd_version(inode) != STAT_DATA_V1)
950 return generic_permission(inode, mask, reiserfs_check_acl);
951 #endif
952 return generic_permission(inode, mask, NULL);
955 /* This will catch lookups from the fs root to .reiserfs_priv */
956 static int
957 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
959 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
960 if (container_of(q1, struct dentry, d_name) == priv_root)
961 return -ENOENT;
962 if (q1->len == name->len &&
963 !memcmp(q1->name, name->name, name->len))
964 return 0;
965 return 1;
968 static const struct dentry_operations xattr_lookup_poison_ops = {
969 .d_compare = xattr_lookup_poison,
972 int reiserfs_lookup_privroot(struct super_block *s)
974 struct dentry *dentry;
975 int err = 0;
977 /* If we don't have the privroot located yet - go find it */
978 mutex_lock(&s->s_root->d_inode->i_mutex);
979 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
980 strlen(PRIVROOT_NAME));
981 if (!IS_ERR(dentry)) {
982 REISERFS_SB(s)->priv_root = dentry;
983 if (!reiserfs_expose_privroot(s))
984 s->s_root->d_op = &xattr_lookup_poison_ops;
985 if (dentry->d_inode)
986 dentry->d_inode->i_flags |= S_PRIVATE;
987 } else
988 err = PTR_ERR(dentry);
989 mutex_unlock(&s->s_root->d_inode->i_mutex);
991 return err;
994 /* We need to take a copy of the mount flags since things like
995 * MS_RDONLY don't get set until *after* we're called.
996 * mount_flags != mount_options */
997 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
999 int err = 0;
1000 struct dentry *privroot = REISERFS_SB(s)->priv_root;
1002 err = xattr_mount_check(s);
1003 if (err)
1004 goto error;
1006 if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
1007 mutex_lock(&s->s_root->d_inode->i_mutex);
1008 err = create_privroot(REISERFS_SB(s)->priv_root);
1009 mutex_unlock(&s->s_root->d_inode->i_mutex);
1012 if (privroot->d_inode) {
1013 s->s_xattr = reiserfs_xattr_handlers;
1014 mutex_lock(&privroot->d_inode->i_mutex);
1015 if (!REISERFS_SB(s)->xattr_root) {
1016 struct dentry *dentry;
1017 dentry = lookup_one_len(XAROOT_NAME, privroot,
1018 strlen(XAROOT_NAME));
1019 if (!IS_ERR(dentry))
1020 REISERFS_SB(s)->xattr_root = dentry;
1021 else
1022 err = PTR_ERR(dentry);
1024 mutex_unlock(&privroot->d_inode->i_mutex);
1027 error:
1028 if (err) {
1029 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1030 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1033 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1034 if (reiserfs_posixacl(s))
1035 s->s_flags |= MS_POSIXACL;
1036 else
1037 s->s_flags &= ~MS_POSIXACL;
1039 return err;