pdc202xx_old: fix resetproc() method
[linux-2.6/mini2440.git] / fs / reiserfs / xattr.c
blobf83f52bae390f6484702f8e470de497b41b59921
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/smp_lock.h>
50 #include <linux/stat.h>
51 #include <linux/quotaops.h>
53 #define PRIVROOT_NAME ".reiserfs_priv"
54 #define XAROOT_NAME "xattrs"
57 /* Helpers for inode ops. We do this so that we don't have all the VFS
58 * overhead and also for proper i_mutex annotation.
59 * dir->i_mutex must be held for all of them. */
60 #ifdef CONFIG_REISERFS_FS_XATTR
61 static int xattr_create(struct inode *dir, struct dentry *dentry, int mode)
63 BUG_ON(!mutex_is_locked(&dir->i_mutex));
64 vfs_dq_init(dir);
65 return dir->i_op->create(dir, dentry, mode, NULL);
67 #endif
69 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode)
71 BUG_ON(!mutex_is_locked(&dir->i_mutex));
72 vfs_dq_init(dir);
73 return dir->i_op->mkdir(dir, dentry, mode);
76 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
77 * mutation ops aren't called during rename or splace, which are the
78 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
79 * better than allocating another subclass just for this code. */
80 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
82 int error;
83 BUG_ON(!mutex_is_locked(&dir->i_mutex));
84 vfs_dq_init(dir);
86 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
87 error = dir->i_op->unlink(dir, dentry);
88 mutex_unlock(&dentry->d_inode->i_mutex);
90 if (!error)
91 d_delete(dentry);
92 return error;
95 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
97 int error;
98 BUG_ON(!mutex_is_locked(&dir->i_mutex));
99 vfs_dq_init(dir);
101 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
102 dentry_unhash(dentry);
103 error = dir->i_op->rmdir(dir, dentry);
104 if (!error)
105 dentry->d_inode->i_flags |= S_DEAD;
106 mutex_unlock(&dentry->d_inode->i_mutex);
107 if (!error)
108 d_delete(dentry);
109 dput(dentry);
111 return error;
114 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
116 /* Returns and possibly creates the xattr dir. */
117 static struct dentry *lookup_or_create_dir(struct dentry *parent,
118 const char *name, int flags)
120 struct dentry *dentry;
121 BUG_ON(!parent);
123 dentry = lookup_one_len(name, parent, strlen(name));
124 if (IS_ERR(dentry))
125 return dentry;
126 else if (!dentry->d_inode) {
127 int err = -ENODATA;
129 if (xattr_may_create(flags)) {
130 mutex_lock_nested(&parent->d_inode->i_mutex,
131 I_MUTEX_XATTR);
132 err = xattr_mkdir(parent->d_inode, dentry, 0700);
133 mutex_unlock(&parent->d_inode->i_mutex);
136 if (err) {
137 dput(dentry);
138 dentry = ERR_PTR(err);
142 return dentry;
145 static struct dentry *open_xa_root(struct super_block *sb, int flags)
147 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
148 if (!privroot)
149 return ERR_PTR(-ENODATA);
150 return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
153 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
155 struct dentry *xaroot, *xadir;
156 char namebuf[17];
158 xaroot = open_xa_root(inode->i_sb, flags);
159 if (IS_ERR(xaroot))
160 return xaroot;
162 snprintf(namebuf, sizeof(namebuf), "%X.%X",
163 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
164 inode->i_generation);
166 xadir = lookup_or_create_dir(xaroot, namebuf, flags);
167 dput(xaroot);
168 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;
188 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
189 return -ENOSPC;
191 if (name[0] == '.' && (name[1] == '\0' ||
192 (name[1] == '.' && name[2] == '\0')))
193 return 0;
195 dentry = lookup_one_len(name, dbuf->xadir, namelen);
196 if (IS_ERR(dentry)) {
197 return PTR_ERR(dentry);
198 } else if (!dentry->d_inode) {
199 /* A directory entry exists, but no file? */
200 reiserfs_error(dentry->d_sb, "xattr-20003",
201 "Corrupted directory: xattr %s listed but "
202 "not found for file %s.\n",
203 dentry->d_name.name, dbuf->xadir->d_name.name);
204 dput(dentry);
205 return -EIO;
208 dbuf->dentries[dbuf->count++] = dentry;
209 return 0;
212 static void
213 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
215 int i;
216 for (i = 0; i < buf->count; i++)
217 if (buf->dentries[i])
218 dput(buf->dentries[i]);
221 static int reiserfs_for_each_xattr(struct inode *inode,
222 int (*action)(struct dentry *, void *),
223 void *data)
225 struct dentry *dir;
226 int i, err = 0;
227 loff_t pos = 0;
228 struct reiserfs_dentry_buf buf = {
229 .count = 0,
232 /* Skip out, an xattr has no xattrs associated with it */
233 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
234 return 0;
236 dir = open_xa_dir(inode, XATTR_REPLACE);
237 if (IS_ERR(dir)) {
238 err = PTR_ERR(dir);
239 goto out;
240 } else if (!dir->d_inode) {
241 err = 0;
242 goto out_dir;
245 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
246 buf.xadir = dir;
247 err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos);
248 while ((err == 0 || err == -ENOSPC) && buf.count) {
249 err = 0;
251 for (i = 0; i < buf.count && buf.dentries[i]; i++) {
252 int lerr = 0;
253 struct dentry *dentry = buf.dentries[i];
255 if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode))
256 lerr = action(dentry, data);
258 dput(dentry);
259 buf.dentries[i] = NULL;
260 err = lerr ?: err;
262 buf.count = 0;
263 if (!err)
264 err = reiserfs_readdir_dentry(dir, &buf,
265 fill_with_dentries, &pos);
267 mutex_unlock(&dir->d_inode->i_mutex);
269 /* Clean up after a failed readdir */
270 cleanup_dentry_buf(&buf);
272 if (!err) {
273 /* We start a transaction here to avoid a ABBA situation
274 * between the xattr root's i_mutex and the journal lock.
275 * This doesn't incur much additional overhead since the
276 * new transaction will just nest inside the
277 * outer transaction. */
278 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
279 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
280 struct reiserfs_transaction_handle th;
281 err = journal_begin(&th, inode->i_sb, blocks);
282 if (!err) {
283 int jerror;
284 mutex_lock_nested(&dir->d_parent->d_inode->i_mutex,
285 I_MUTEX_XATTR);
286 err = action(dir, data);
287 jerror = journal_end(&th, inode->i_sb, blocks);
288 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
289 err = jerror ?: err;
292 out_dir:
293 dput(dir);
294 out:
295 /* -ENODATA isn't an error */
296 if (err == -ENODATA)
297 err = 0;
298 return err;
301 static int delete_one_xattr(struct dentry *dentry, void *data)
303 struct inode *dir = dentry->d_parent->d_inode;
305 /* This is the xattr dir, handle specially. */
306 if (S_ISDIR(dentry->d_inode->i_mode))
307 return xattr_rmdir(dir, dentry);
309 return xattr_unlink(dir, dentry);
312 static int chown_one_xattr(struct dentry *dentry, void *data)
314 struct iattr *attrs = data;
315 return reiserfs_setattr(dentry, attrs);
318 /* No i_mutex, but the inode is unconnected. */
319 int reiserfs_delete_xattrs(struct inode *inode)
321 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
322 if (err)
323 reiserfs_warning(inode->i_sb, "jdm-20004",
324 "Couldn't delete all xattrs (%d)\n", err);
325 return err;
328 /* inode->i_mutex: down */
329 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
331 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
332 if (err)
333 reiserfs_warning(inode->i_sb, "jdm-20007",
334 "Couldn't chown all xattrs (%d)\n", err);
335 return err;
338 #ifdef CONFIG_REISERFS_FS_XATTR
339 /* Returns a dentry corresponding to a specific extended attribute file
340 * for the inode. If flags allow, the file is created. Otherwise, a
341 * valid or negative dentry, or an error is returned. */
342 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
343 int flags)
345 struct dentry *xadir, *xafile;
346 int err = 0;
348 xadir = open_xa_dir(inode, flags);
349 if (IS_ERR(xadir))
350 return ERR_CAST(xadir);
352 xafile = lookup_one_len(name, xadir, strlen(name));
353 if (IS_ERR(xafile)) {
354 err = PTR_ERR(xafile);
355 goto out;
358 if (xafile->d_inode && (flags & XATTR_CREATE))
359 err = -EEXIST;
361 if (!xafile->d_inode) {
362 err = -ENODATA;
363 if (xattr_may_create(flags)) {
364 mutex_lock_nested(&xadir->d_inode->i_mutex,
365 I_MUTEX_XATTR);
366 err = xattr_create(xadir->d_inode, xafile,
367 0700|S_IFREG);
368 mutex_unlock(&xadir->d_inode->i_mutex);
372 if (err)
373 dput(xafile);
374 out:
375 dput(xadir);
376 if (err)
377 return ERR_PTR(err);
378 return xafile;
381 /* Internal operations on file data */
382 static inline void reiserfs_put_page(struct page *page)
384 kunmap(page);
385 page_cache_release(page);
388 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
390 struct address_space *mapping = dir->i_mapping;
391 struct page *page;
392 /* We can deadlock if we try to free dentries,
393 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
394 mapping_set_gfp_mask(mapping, GFP_NOFS);
395 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
396 if (!IS_ERR(page)) {
397 kmap(page);
398 if (PageError(page))
399 goto fail;
401 return page;
403 fail:
404 reiserfs_put_page(page);
405 return ERR_PTR(-EIO);
408 static inline __u32 xattr_hash(const char *msg, int len)
410 return csum_partial(msg, len, 0);
413 int reiserfs_commit_write(struct file *f, struct page *page,
414 unsigned from, unsigned to);
415 int reiserfs_prepare_write(struct file *f, struct page *page,
416 unsigned from, unsigned to);
418 static void update_ctime(struct inode *inode)
420 struct timespec now = current_fs_time(inode->i_sb);
421 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
422 timespec_equal(&inode->i_ctime, &now))
423 return;
425 inode->i_ctime = CURRENT_TIME_SEC;
426 mark_inode_dirty(inode);
429 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
431 int err = 0;
432 struct dentry *dentry, *xadir;
434 xadir = open_xa_dir(inode, XATTR_REPLACE);
435 if (IS_ERR(xadir))
436 return PTR_ERR(xadir);
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 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
446 err = xattr_unlink(xadir->d_inode, dentry);
447 mutex_unlock(&xadir->d_inode->i_mutex);
448 update_ctime(inode);
451 dput(dentry);
452 out_dput:
453 dput(xadir);
454 return err;
458 /* Generic extended attribute operations that can be used by xa plugins */
461 * inode->i_mutex: down
464 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
465 struct inode *inode, const char *name,
466 const void *buffer, size_t buffer_size, int flags)
468 int err = 0;
469 struct dentry *dentry;
470 struct page *page;
471 char *data;
472 size_t file_pos = 0;
473 size_t buffer_pos = 0;
474 size_t new_size;
475 __u32 xahash = 0;
477 if (get_inode_sd_version(inode) == STAT_DATA_V1)
478 return -EOPNOTSUPP;
480 if (!buffer)
481 return lookup_and_delete_xattr(inode, name);
483 dentry = xattr_lookup(inode, name, flags);
484 if (IS_ERR(dentry))
485 return PTR_ERR(dentry);
487 down_write(&REISERFS_I(inode)->i_xattr_sem);
489 xahash = xattr_hash(buffer, buffer_size);
490 while (buffer_pos < buffer_size || buffer_pos == 0) {
491 size_t chunk;
492 size_t skip = 0;
493 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
494 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
495 chunk = PAGE_CACHE_SIZE;
496 else
497 chunk = buffer_size - buffer_pos;
499 page = reiserfs_get_page(dentry->d_inode, file_pos);
500 if (IS_ERR(page)) {
501 err = PTR_ERR(page);
502 goto out_unlock;
505 lock_page(page);
506 data = page_address(page);
508 if (file_pos == 0) {
509 struct reiserfs_xattr_header *rxh;
510 skip = file_pos = sizeof(struct reiserfs_xattr_header);
511 if (chunk + skip > PAGE_CACHE_SIZE)
512 chunk = PAGE_CACHE_SIZE - skip;
513 rxh = (struct reiserfs_xattr_header *)data;
514 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
515 rxh->h_hash = cpu_to_le32(xahash);
518 err = reiserfs_prepare_write(NULL, page, page_offset,
519 page_offset + chunk + skip);
520 if (!err) {
521 if (buffer)
522 memcpy(data + skip, buffer + buffer_pos, chunk);
523 err = reiserfs_commit_write(NULL, page, page_offset,
524 page_offset + chunk +
525 skip);
527 unlock_page(page);
528 reiserfs_put_page(page);
529 buffer_pos += chunk;
530 file_pos += chunk;
531 skip = 0;
532 if (err || buffer_size == 0 || !buffer)
533 break;
536 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
537 if (!err && new_size < i_size_read(dentry->d_inode)) {
538 struct iattr newattrs = {
539 .ia_ctime = current_fs_time(inode->i_sb),
540 .ia_size = buffer_size,
541 .ia_valid = ATTR_SIZE | ATTR_CTIME,
543 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
544 down_write(&dentry->d_inode->i_alloc_sem);
545 err = reiserfs_setattr(dentry, &newattrs);
546 up_write(&dentry->d_inode->i_alloc_sem);
547 mutex_unlock(&dentry->d_inode->i_mutex);
548 } else
549 update_ctime(inode);
550 out_unlock:
551 up_write(&REISERFS_I(inode)->i_xattr_sem);
552 dput(dentry);
553 return err;
556 /* We need to start a transaction to maintain lock ordering */
557 int reiserfs_xattr_set(struct inode *inode, const char *name,
558 const void *buffer, size_t buffer_size, int flags)
561 struct reiserfs_transaction_handle th;
562 int error, error2;
563 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
565 if (!(flags & XATTR_REPLACE))
566 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
568 reiserfs_write_lock(inode->i_sb);
569 error = journal_begin(&th, inode->i_sb, jbegin_count);
570 if (error) {
571 reiserfs_write_unlock(inode->i_sb);
572 return error;
575 error = reiserfs_xattr_set_handle(&th, inode, name,
576 buffer, buffer_size, flags);
578 error2 = journal_end(&th, inode->i_sb, jbegin_count);
579 if (error == 0)
580 error = error2;
581 reiserfs_write_unlock(inode->i_sb);
583 return error;
587 * inode->i_mutex: down
590 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
591 size_t buffer_size)
593 ssize_t err = 0;
594 struct dentry *dentry;
595 size_t isize;
596 size_t file_pos = 0;
597 size_t buffer_pos = 0;
598 struct page *page;
599 __u32 hash = 0;
601 if (name == NULL)
602 return -EINVAL;
604 /* We can't have xattrs attached to v1 items since they don't have
605 * generation numbers */
606 if (get_inode_sd_version(inode) == STAT_DATA_V1)
607 return -EOPNOTSUPP;
609 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
610 if (IS_ERR(dentry)) {
611 err = PTR_ERR(dentry);
612 goto out;
615 down_read(&REISERFS_I(inode)->i_xattr_sem);
617 isize = i_size_read(dentry->d_inode);
619 /* Just return the size needed */
620 if (buffer == NULL) {
621 err = isize - sizeof(struct reiserfs_xattr_header);
622 goto out_unlock;
625 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
626 err = -ERANGE;
627 goto out_unlock;
630 while (file_pos < isize) {
631 size_t chunk;
632 char *data;
633 size_t skip = 0;
634 if (isize - file_pos > PAGE_CACHE_SIZE)
635 chunk = PAGE_CACHE_SIZE;
636 else
637 chunk = isize - file_pos;
639 page = reiserfs_get_page(dentry->d_inode, file_pos);
640 if (IS_ERR(page)) {
641 err = PTR_ERR(page);
642 goto out_unlock;
645 lock_page(page);
646 data = page_address(page);
647 if (file_pos == 0) {
648 struct reiserfs_xattr_header *rxh =
649 (struct reiserfs_xattr_header *)data;
650 skip = file_pos = sizeof(struct reiserfs_xattr_header);
651 chunk -= skip;
652 /* Magic doesn't match up.. */
653 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
654 unlock_page(page);
655 reiserfs_put_page(page);
656 reiserfs_warning(inode->i_sb, "jdm-20001",
657 "Invalid magic for xattr (%s) "
658 "associated with %k", name,
659 INODE_PKEY(inode));
660 err = -EIO;
661 goto out_unlock;
663 hash = le32_to_cpu(rxh->h_hash);
665 memcpy(buffer + buffer_pos, data + skip, chunk);
666 unlock_page(page);
667 reiserfs_put_page(page);
668 file_pos += chunk;
669 buffer_pos += chunk;
670 skip = 0;
672 err = isize - sizeof(struct reiserfs_xattr_header);
674 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
675 hash) {
676 reiserfs_warning(inode->i_sb, "jdm-20002",
677 "Invalid hash for xattr (%s) associated "
678 "with %k", name, INODE_PKEY(inode));
679 err = -EIO;
682 out_unlock:
683 up_read(&REISERFS_I(inode)->i_xattr_sem);
684 dput(dentry);
686 out:
687 return err;
690 /* Actual operations that are exported to VFS-land */
691 struct xattr_handler *reiserfs_xattr_handlers[] = {
692 &reiserfs_xattr_user_handler,
693 &reiserfs_xattr_trusted_handler,
694 #ifdef CONFIG_REISERFS_FS_SECURITY
695 &reiserfs_xattr_security_handler,
696 #endif
697 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
698 &reiserfs_posix_acl_access_handler,
699 &reiserfs_posix_acl_default_handler,
700 #endif
701 NULL
705 * In order to implement different sets of xattr operations for each xattr
706 * prefix with the generic xattr API, a filesystem should create a
707 * null-terminated array of struct xattr_handler (one for each prefix) and
708 * hang a pointer to it off of the s_xattr field of the superblock.
710 * The generic_fooxattr() functions will use this list to dispatch xattr
711 * operations to the correct xattr_handler.
713 #define for_each_xattr_handler(handlers, handler) \
714 for ((handler) = *(handlers)++; \
715 (handler) != NULL; \
716 (handler) = *(handlers)++)
718 /* This is the implementation for the xattr plugin infrastructure */
719 static inline struct xattr_handler *
720 find_xattr_handler_prefix(struct xattr_handler **handlers,
721 const char *name)
723 struct xattr_handler *xah;
725 if (!handlers)
726 return NULL;
728 for_each_xattr_handler(handlers, xah) {
729 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
730 break;
733 return xah;
738 * Inode operation getxattr()
740 ssize_t
741 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
742 size_t size)
744 struct inode *inode = dentry->d_inode;
745 struct xattr_handler *handler;
747 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
749 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
750 return -EOPNOTSUPP;
752 return handler->get(inode, name, buffer, size);
756 * Inode operation setxattr()
758 * dentry->d_inode->i_mutex down
761 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
762 size_t size, int flags)
764 struct inode *inode = dentry->d_inode;
765 struct xattr_handler *handler;
767 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
769 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
770 return -EOPNOTSUPP;
772 return handler->set(inode, name, value, size, flags);
776 * Inode operation removexattr()
778 * dentry->d_inode->i_mutex down
780 int reiserfs_removexattr(struct dentry *dentry, const char *name)
782 struct inode *inode = dentry->d_inode;
783 struct xattr_handler *handler;
784 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
786 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
787 return -EOPNOTSUPP;
789 return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
792 struct listxattr_buf {
793 size_t size;
794 size_t pos;
795 char *buf;
796 struct inode *inode;
799 static int listxattr_filler(void *buf, const char *name, int namelen,
800 loff_t offset, u64 ino, unsigned int d_type)
802 struct listxattr_buf *b = (struct listxattr_buf *)buf;
803 size_t size;
804 if (name[0] != '.' ||
805 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
806 struct xattr_handler *handler;
807 handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
808 name);
809 if (!handler) /* Unsupported xattr name */
810 return 0;
811 if (b->buf) {
812 size = handler->list(b->inode, b->buf + b->pos,
813 b->size, name, namelen);
814 if (size > b->size)
815 return -ERANGE;
816 } else {
817 size = handler->list(b->inode, NULL, 0, name, namelen);
820 b->pos += size;
822 return 0;
826 * Inode operation listxattr()
828 * We totally ignore the generic listxattr here because it would be stupid
829 * not to. Since the xattrs are organized in a directory, we can just
830 * readdir to find them.
832 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
834 struct dentry *dir;
835 int err = 0;
836 loff_t pos = 0;
837 struct listxattr_buf buf = {
838 .inode = dentry->d_inode,
839 .buf = buffer,
840 .size = buffer ? size : 0,
843 if (!dentry->d_inode)
844 return -EINVAL;
846 if (!reiserfs_xattrs(dentry->d_sb) ||
847 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
848 return -EOPNOTSUPP;
850 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
851 if (IS_ERR(dir)) {
852 err = PTR_ERR(dir);
853 if (err == -ENODATA)
854 err = 0; /* Not an error if there aren't any xattrs */
855 goto out;
858 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
859 err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos);
860 mutex_unlock(&dir->d_inode->i_mutex);
862 if (!err)
863 err = buf.pos;
865 dput(dir);
866 out:
867 return err;
870 static int reiserfs_check_acl(struct inode *inode, int mask)
872 struct posix_acl *acl;
873 int error = -EAGAIN; /* do regular unix permission checks by default */
875 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
877 if (acl) {
878 if (!IS_ERR(acl)) {
879 error = posix_acl_permission(inode, acl, mask);
880 posix_acl_release(acl);
881 } else if (PTR_ERR(acl) != -ENODATA)
882 error = PTR_ERR(acl);
885 return error;
888 int reiserfs_permission(struct inode *inode, int mask)
891 * We don't do permission checks on the internal objects.
892 * Permissions are determined by the "owning" object.
894 if (IS_PRIVATE(inode))
895 return 0;
897 * Stat data v1 doesn't support ACLs.
899 if (get_inode_sd_version(inode) == STAT_DATA_V1)
900 return generic_permission(inode, mask, NULL);
901 else
902 return generic_permission(inode, mask, reiserfs_check_acl);
905 static int create_privroot(struct dentry *dentry)
907 int err;
908 struct inode *inode = dentry->d_parent->d_inode;
909 mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
910 err = xattr_mkdir(inode, dentry, 0700);
911 mutex_unlock(&inode->i_mutex);
912 if (err) {
913 dput(dentry);
914 dentry = NULL;
917 if (dentry && dentry->d_inode)
918 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
919 "storage.\n", PRIVROOT_NAME);
921 return err;
924 static int xattr_mount_check(struct super_block *s)
926 /* We need generation numbers to ensure that the oid mapping is correct
927 * v3.5 filesystems don't have them. */
928 if (old_format_only(s)) {
929 if (reiserfs_xattrs_optional(s)) {
930 /* Old format filesystem, but optional xattrs have
931 * been enabled. Error out. */
932 reiserfs_warning(s, "jdm-2005",
933 "xattrs/ACLs not supported "
934 "on pre-v3.6 format filesystems. "
935 "Failing mount.");
936 return -EOPNOTSUPP;
940 return 0;
943 #else
944 int __init reiserfs_xattr_register_handlers(void) { return 0; }
945 void reiserfs_xattr_unregister_handlers(void) {}
946 #endif
948 /* This will catch lookups from the fs root to .reiserfs_priv */
949 static int
950 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
952 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
953 if (name->len == priv_root->d_name.len &&
954 name->hash == priv_root->d_name.hash &&
955 !memcmp(name->name, priv_root->d_name.name, name->len)) {
956 return -ENOENT;
957 } else if (q1->len == name->len &&
958 !memcmp(q1->name, name->name, name->len))
959 return 0;
960 return 1;
963 static const struct dentry_operations xattr_lookup_poison_ops = {
964 .d_compare = xattr_lookup_poison,
967 /* We need to take a copy of the mount flags since things like
968 * MS_RDONLY don't get set until *after* we're called.
969 * mount_flags != mount_options */
970 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
972 int err = 0;
974 #ifdef CONFIG_REISERFS_FS_XATTR
975 err = xattr_mount_check(s);
976 if (err)
977 goto error;
978 #endif
980 /* If we don't have the privroot located yet - go find it */
981 if (!REISERFS_SB(s)->priv_root) {
982 struct dentry *dentry;
983 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
984 strlen(PRIVROOT_NAME));
985 if (!IS_ERR(dentry)) {
986 #ifdef CONFIG_REISERFS_FS_XATTR
987 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode)
988 err = create_privroot(dentry);
989 #endif
990 if (!dentry->d_inode) {
991 dput(dentry);
992 dentry = NULL;
994 } else
995 err = PTR_ERR(dentry);
997 if (!err && dentry) {
998 s->s_root->d_op = &xattr_lookup_poison_ops;
999 dentry->d_inode->i_flags |= S_PRIVATE;
1000 REISERFS_SB(s)->priv_root = dentry;
1001 #ifdef CONFIG_REISERFS_FS_XATTR
1002 /* xattrs are unavailable */
1003 } else if (!(mount_flags & MS_RDONLY)) {
1004 /* If we're read-only it just means that the dir
1005 * hasn't been created. Not an error -- just no
1006 * xattrs on the fs. We'll check again if we
1007 * go read-write */
1008 reiserfs_warning(s, "jdm-20006",
1009 "xattrs/ACLs enabled and couldn't "
1010 "find/create .reiserfs_priv. "
1011 "Failing mount.");
1012 err = -EOPNOTSUPP;
1013 #endif
1017 #ifdef CONFIG_REISERFS_FS_XATTR
1018 if (!err)
1019 s->s_xattr = reiserfs_xattr_handlers;
1021 error:
1022 if (err) {
1023 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1024 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1026 #endif
1028 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1029 s->s_flags = s->s_flags & ~MS_POSIXACL;
1030 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1031 if (reiserfs_posixacl(s))
1032 s->s_flags |= MS_POSIXACL;
1033 #endif
1035 return err;