2 * linux/fs/reiserfs/xattr.c
4 * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
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
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.
37 #include <linux/capability.h>
38 #include <linux/dcache.h>
39 #include <linux/namei.h>
40 #include <linux/errno.h>
41 #include <linux/gfp.h>
43 #include <linux/file.h>
44 #include <linux/pagemap.h>
45 #include <linux/xattr.h>
48 #include <asm/uaccess.h>
49 #include <net/checksum.h>
50 #include <linux/stat.h>
51 #include <linux/quotaops.h>
52 #include <linux/security.h>
53 #include <linux/posix_acl_xattr.h>
55 #define PRIVROOT_NAME ".reiserfs_priv"
56 #define XAROOT_NAME "xattrs"
60 * Helpers for inode ops. We do this so that we don't have all the VFS
61 * overhead and also for proper i_mutex annotation.
62 * dir->i_mutex must be held for all of them.
64 #ifdef CONFIG_REISERFS_FS_XATTR
65 static int xattr_create(struct inode *dir, struct dentry *dentry, int mode)
67 BUG_ON(!mutex_is_locked(&dir->i_mutex));
68 return dir->i_op->create(dir, dentry, mode, true);
72 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
74 BUG_ON(!mutex_is_locked(&dir->i_mutex));
75 return dir->i_op->mkdir(dir, dentry, mode);
79 * We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
80 * mutation ops aren't called during rename or splace, which are the
81 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
82 * better than allocating another subclass just for this code.
84 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
87 BUG_ON(!mutex_is_locked(&dir->i_mutex));
89 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
90 error = dir->i_op->unlink(dir, dentry);
91 mutex_unlock(&dentry->d_inode->i_mutex);
98 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
101 BUG_ON(!mutex_is_locked(&dir->i_mutex));
103 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
104 error = dir->i_op->rmdir(dir, dentry);
106 dentry->d_inode->i_flags |= S_DEAD;
107 mutex_unlock(&dentry->d_inode->i_mutex);
114 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
116 static struct dentry *open_xa_root(struct super_block *sb, int flags)
118 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
119 struct dentry *xaroot;
120 if (!privroot->d_inode)
121 return ERR_PTR(-ENODATA);
123 mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
125 xaroot = dget(REISERFS_SB(sb)->xattr_root);
127 xaroot = ERR_PTR(-ENODATA);
128 else if (!xaroot->d_inode) {
130 if (xattr_may_create(flags))
131 err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
134 xaroot = ERR_PTR(err);
138 mutex_unlock(&privroot->d_inode->i_mutex);
142 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
144 struct dentry *xaroot, *xadir;
147 xaroot = open_xa_root(inode->i_sb, flags);
151 snprintf(namebuf, sizeof(namebuf), "%X.%X",
152 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
153 inode->i_generation);
155 mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
157 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
158 if (!IS_ERR(xadir) && !xadir->d_inode) {
160 if (xattr_may_create(flags))
161 err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
164 xadir = ERR_PTR(err);
168 mutex_unlock(&xaroot->d_inode->i_mutex);
174 * The following are side effects of other operations that aren't explicitly
175 * modifying extended attributes. This includes operations such as permissions
176 * or ownership changes, object deletions, etc.
178 struct reiserfs_dentry_buf {
179 struct dir_context ctx;
180 struct dentry *xadir;
182 struct dentry *dentries[8];
186 fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
187 u64 ino, unsigned int d_type)
189 struct reiserfs_dentry_buf *dbuf = buf;
190 struct dentry *dentry;
191 WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
193 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
196 if (name[0] == '.' && (namelen < 2 ||
197 (namelen == 2 && name[1] == '.')))
200 dentry = lookup_one_len(name, dbuf->xadir, namelen);
201 if (IS_ERR(dentry)) {
202 return PTR_ERR(dentry);
203 } else if (!dentry->d_inode) {
204 /* A directory entry exists, but no file? */
205 reiserfs_error(dentry->d_sb, "xattr-20003",
206 "Corrupted directory: xattr %s listed but "
207 "not found for file %s.\n",
208 dentry->d_name.name, dbuf->xadir->d_name.name);
213 dbuf->dentries[dbuf->count++] = dentry;
218 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
221 for (i = 0; i < buf->count; i++)
222 if (buf->dentries[i])
223 dput(buf->dentries[i]);
226 static int reiserfs_for_each_xattr(struct inode *inode,
227 int (*action)(struct dentry *, void *),
232 struct reiserfs_dentry_buf buf = {
233 .ctx.actor = fill_with_dentries,
236 /* Skip out, an xattr has no xattrs associated with it */
237 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
240 dir = open_xa_dir(inode, XATTR_REPLACE);
244 } else if (!dir->d_inode) {
249 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
253 err = reiserfs_readdir_inode(dir->d_inode, &buf.ctx);
258 for (i = 0; !err && i < buf.count && buf.dentries[i]; i++) {
259 struct dentry *dentry = buf.dentries[i];
261 if (!S_ISDIR(dentry->d_inode->i_mode))
262 err = action(dentry, data);
265 buf.dentries[i] = NULL;
271 mutex_unlock(&dir->d_inode->i_mutex);
273 cleanup_dentry_buf(&buf);
277 * We start a transaction here to avoid a ABBA situation
278 * between the xattr root's i_mutex and the journal lock.
279 * This doesn't incur much additional overhead since the
280 * new transaction will just nest inside the
283 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
284 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
285 struct reiserfs_transaction_handle th;
286 reiserfs_write_lock(inode->i_sb);
287 err = journal_begin(&th, inode->i_sb, blocks);
288 reiserfs_write_unlock(inode->i_sb);
291 mutex_lock_nested(&dir->d_parent->d_inode->i_mutex,
293 err = action(dir, data);
294 reiserfs_write_lock(inode->i_sb);
295 jerror = journal_end(&th);
296 reiserfs_write_unlock(inode->i_sb);
297 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
304 /* -ENODATA isn't an error */
310 static int delete_one_xattr(struct dentry *dentry, void *data)
312 struct inode *dir = dentry->d_parent->d_inode;
314 /* This is the xattr dir, handle specially. */
315 if (S_ISDIR(dentry->d_inode->i_mode))
316 return xattr_rmdir(dir, dentry);
318 return xattr_unlink(dir, dentry);
321 static int chown_one_xattr(struct dentry *dentry, void *data)
323 struct iattr *attrs = data;
324 int ia_valid = attrs->ia_valid;
328 * We only want the ownership bits. Otherwise, we'll do
329 * things like change a directory to a regular file if
332 attrs->ia_valid &= (ATTR_UID|ATTR_GID);
333 err = reiserfs_setattr(dentry, attrs);
334 attrs->ia_valid = ia_valid;
339 /* No i_mutex, but the inode is unconnected. */
340 int reiserfs_delete_xattrs(struct inode *inode)
342 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
344 reiserfs_warning(inode->i_sb, "jdm-20004",
345 "Couldn't delete all xattrs (%d)\n", err);
349 /* inode->i_mutex: down */
350 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
352 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
354 reiserfs_warning(inode->i_sb, "jdm-20007",
355 "Couldn't chown all xattrs (%d)\n", err);
359 #ifdef CONFIG_REISERFS_FS_XATTR
361 * Returns a dentry corresponding to a specific extended attribute file
362 * for the inode. If flags allow, the file is created. Otherwise, a
363 * valid or negative dentry, or an error is returned.
365 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
368 struct dentry *xadir, *xafile;
371 xadir = open_xa_dir(inode, flags);
373 return ERR_CAST(xadir);
375 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
376 xafile = lookup_one_len(name, xadir, strlen(name));
377 if (IS_ERR(xafile)) {
378 err = PTR_ERR(xafile);
382 if (xafile->d_inode && (flags & XATTR_CREATE))
385 if (!xafile->d_inode) {
387 if (xattr_may_create(flags))
388 err = xattr_create(xadir->d_inode, xafile,
395 mutex_unlock(&xadir->d_inode->i_mutex);
402 /* Internal operations on file data */
403 static inline void reiserfs_put_page(struct page *page)
406 page_cache_release(page);
409 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
411 struct address_space *mapping = dir->i_mapping;
414 * We can deadlock if we try to free dentries,
415 * and an unlink/rmdir has just occurred - GFP_NOFS avoids this
417 mapping_set_gfp_mask(mapping, GFP_NOFS);
418 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
427 reiserfs_put_page(page);
428 return ERR_PTR(-EIO);
431 static inline __u32 xattr_hash(const char *msg, int len)
433 return csum_partial(msg, len, 0);
436 int reiserfs_commit_write(struct file *f, struct page *page,
437 unsigned from, unsigned to);
439 static void update_ctime(struct inode *inode)
441 struct timespec now = current_fs_time(inode->i_sb);
442 if (inode_unhashed(inode) || !inode->i_nlink ||
443 timespec_equal(&inode->i_ctime, &now))
446 inode->i_ctime = CURRENT_TIME_SEC;
447 mark_inode_dirty(inode);
450 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
453 struct dentry *dentry, *xadir;
455 xadir = open_xa_dir(inode, XATTR_REPLACE);
457 return PTR_ERR(xadir);
459 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
460 dentry = lookup_one_len(name, xadir, strlen(name));
461 if (IS_ERR(dentry)) {
462 err = PTR_ERR(dentry);
466 if (dentry->d_inode) {
467 err = xattr_unlink(xadir->d_inode, dentry);
473 mutex_unlock(&xadir->d_inode->i_mutex);
479 /* Generic extended attribute operations that can be used by xa plugins */
482 * inode->i_mutex: down
485 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
486 struct inode *inode, const char *name,
487 const void *buffer, size_t buffer_size, int flags)
490 struct dentry *dentry;
494 size_t buffer_pos = 0;
498 if (get_inode_sd_version(inode) == STAT_DATA_V1)
502 err = lookup_and_delete_xattr(inode, name);
506 dentry = xattr_lookup(inode, name, flags);
508 return PTR_ERR(dentry);
510 down_write(&REISERFS_I(inode)->i_xattr_sem);
512 xahash = xattr_hash(buffer, buffer_size);
513 while (buffer_pos < buffer_size || buffer_pos == 0) {
516 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
517 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
518 chunk = PAGE_CACHE_SIZE;
520 chunk = buffer_size - buffer_pos;
522 page = reiserfs_get_page(dentry->d_inode, file_pos);
529 data = page_address(page);
532 struct reiserfs_xattr_header *rxh;
533 skip = file_pos = sizeof(struct reiserfs_xattr_header);
534 if (chunk + skip > PAGE_CACHE_SIZE)
535 chunk = PAGE_CACHE_SIZE - skip;
536 rxh = (struct reiserfs_xattr_header *)data;
537 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
538 rxh->h_hash = cpu_to_le32(xahash);
541 reiserfs_write_lock(inode->i_sb);
542 err = __reiserfs_write_begin(page, page_offset, chunk + skip);
545 memcpy(data + skip, buffer + buffer_pos, chunk);
546 err = reiserfs_commit_write(NULL, page, page_offset,
547 page_offset + chunk +
550 reiserfs_write_unlock(inode->i_sb);
552 reiserfs_put_page(page);
556 if (err || buffer_size == 0 || !buffer)
560 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
561 if (!err && new_size < i_size_read(dentry->d_inode)) {
562 struct iattr newattrs = {
563 .ia_ctime = current_fs_time(inode->i_sb),
565 .ia_valid = ATTR_SIZE | ATTR_CTIME,
568 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
569 inode_dio_wait(dentry->d_inode);
571 err = reiserfs_setattr(dentry, &newattrs);
572 mutex_unlock(&dentry->d_inode->i_mutex);
576 up_write(&REISERFS_I(inode)->i_xattr_sem);
581 /* We need to start a transaction to maintain lock ordering */
582 int reiserfs_xattr_set(struct inode *inode, const char *name,
583 const void *buffer, size_t buffer_size, int flags)
586 struct reiserfs_transaction_handle th;
588 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
590 if (!(flags & XATTR_REPLACE))
591 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
593 reiserfs_write_lock(inode->i_sb);
594 error = journal_begin(&th, inode->i_sb, jbegin_count);
595 reiserfs_write_unlock(inode->i_sb);
600 error = reiserfs_xattr_set_handle(&th, inode, name,
601 buffer, buffer_size, flags);
603 reiserfs_write_lock(inode->i_sb);
604 error2 = journal_end(&th);
605 reiserfs_write_unlock(inode->i_sb);
613 * inode->i_mutex: down
616 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
620 struct dentry *dentry;
623 size_t buffer_pos = 0;
631 * We can't have xattrs attached to v1 items since they don't have
634 if (get_inode_sd_version(inode) == STAT_DATA_V1)
637 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
638 if (IS_ERR(dentry)) {
639 err = PTR_ERR(dentry);
643 down_read(&REISERFS_I(inode)->i_xattr_sem);
645 isize = i_size_read(dentry->d_inode);
647 /* Just return the size needed */
648 if (buffer == NULL) {
649 err = isize - sizeof(struct reiserfs_xattr_header);
653 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
658 while (file_pos < isize) {
662 if (isize - file_pos > PAGE_CACHE_SIZE)
663 chunk = PAGE_CACHE_SIZE;
665 chunk = isize - file_pos;
667 page = reiserfs_get_page(dentry->d_inode, file_pos);
674 data = page_address(page);
676 struct reiserfs_xattr_header *rxh =
677 (struct reiserfs_xattr_header *)data;
678 skip = file_pos = sizeof(struct reiserfs_xattr_header);
680 /* Magic doesn't match up.. */
681 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
683 reiserfs_put_page(page);
684 reiserfs_warning(inode->i_sb, "jdm-20001",
685 "Invalid magic for xattr (%s) "
686 "associated with %k", name,
691 hash = le32_to_cpu(rxh->h_hash);
693 memcpy(buffer + buffer_pos, data + skip, chunk);
695 reiserfs_put_page(page);
700 err = isize - sizeof(struct reiserfs_xattr_header);
702 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
704 reiserfs_warning(inode->i_sb, "jdm-20002",
705 "Invalid hash for xattr (%s) associated "
706 "with %k", name, INODE_PKEY(inode));
711 up_read(&REISERFS_I(inode)->i_xattr_sem);
719 * In order to implement different sets of xattr operations for each xattr
720 * prefix with the generic xattr API, a filesystem should create a
721 * null-terminated array of struct xattr_handler (one for each prefix) and
722 * hang a pointer to it off of the s_xattr field of the superblock.
724 * The generic_fooxattr() functions will use this list to dispatch xattr
725 * operations to the correct xattr_handler.
727 #define for_each_xattr_handler(handlers, handler) \
728 for ((handler) = *(handlers)++; \
730 (handler) = *(handlers)++)
732 /* This is the implementation for the xattr plugin infrastructure */
733 static inline const struct xattr_handler *
734 find_xattr_handler_prefix(const struct xattr_handler **handlers,
737 const struct xattr_handler *xah;
742 for_each_xattr_handler(handlers, xah) {
743 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
752 * Inode operation getxattr()
755 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
758 const struct xattr_handler *handler;
760 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
762 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
765 return handler->get(dentry, name, buffer, size, handler->flags);
769 * Inode operation setxattr()
771 * dentry->d_inode->i_mutex down
774 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
775 size_t size, int flags)
777 const struct xattr_handler *handler;
779 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
781 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
784 return handler->set(dentry, name, value, size, flags, handler->flags);
788 * Inode operation removexattr()
790 * dentry->d_inode->i_mutex down
792 int reiserfs_removexattr(struct dentry *dentry, const char *name)
794 const struct xattr_handler *handler;
795 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
797 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
800 return handler->set(dentry, name, NULL, 0, XATTR_REPLACE, handler->flags);
803 struct listxattr_buf {
804 struct dir_context ctx;
808 struct dentry *dentry;
811 static int listxattr_filler(void *buf, const char *name, int namelen,
812 loff_t offset, u64 ino, unsigned int d_type)
814 struct listxattr_buf *b = (struct listxattr_buf *)buf;
816 if (name[0] != '.' ||
817 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
818 const struct xattr_handler *handler;
819 handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr,
821 if (!handler) /* Unsupported xattr name */
824 size = handler->list(b->dentry, b->buf + b->pos,
825 b->size, name, namelen,
830 size = handler->list(b->dentry, NULL, 0, name,
831 namelen, handler->flags);
840 * Inode operation listxattr()
842 * We totally ignore the generic listxattr here because it would be stupid
843 * not to. Since the xattrs are organized in a directory, we can just
844 * readdir to find them.
846 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
850 struct listxattr_buf buf = {
851 .ctx.actor = listxattr_filler,
854 .size = buffer ? size : 0,
857 if (!dentry->d_inode)
860 if (!dentry->d_sb->s_xattr ||
861 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
864 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
868 err = 0; /* Not an error if there aren't any xattrs */
872 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
873 err = reiserfs_readdir_inode(dir->d_inode, &buf.ctx);
874 mutex_unlock(&dir->d_inode->i_mutex);
884 static int create_privroot(struct dentry *dentry)
887 struct inode *inode = dentry->d_parent->d_inode;
888 WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
890 err = xattr_mkdir(inode, dentry, 0700);
891 if (err || !dentry->d_inode) {
892 reiserfs_warning(dentry->d_sb, "jdm-20006",
893 "xattrs/ACLs enabled and couldn't "
894 "find/create .reiserfs_priv. "
899 dentry->d_inode->i_flags |= S_PRIVATE;
900 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
901 "storage.\n", PRIVROOT_NAME);
907 int __init reiserfs_xattr_register_handlers(void) { return 0; }
908 void reiserfs_xattr_unregister_handlers(void) {}
909 static int create_privroot(struct dentry *dentry) { return 0; }
912 /* Actual operations that are exported to VFS-land */
913 static const struct xattr_handler *reiserfs_xattr_handlers[] = {
914 #ifdef CONFIG_REISERFS_FS_XATTR
915 &reiserfs_xattr_user_handler,
916 &reiserfs_xattr_trusted_handler,
918 #ifdef CONFIG_REISERFS_FS_SECURITY
919 &reiserfs_xattr_security_handler,
921 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
922 &posix_acl_access_xattr_handler,
923 &posix_acl_default_xattr_handler,
928 static int xattr_mount_check(struct super_block *s)
931 * We need generation numbers to ensure that the oid mapping is correct
932 * v3.5 filesystems don't have them.
934 if (old_format_only(s)) {
935 if (reiserfs_xattrs_optional(s)) {
937 * Old format filesystem, but optional xattrs have
938 * been enabled. Error out.
940 reiserfs_warning(s, "jdm-2005",
941 "xattrs/ACLs not supported "
942 "on pre-v3.6 format filesystems. "
951 int reiserfs_permission(struct inode *inode, int mask)
954 * We don't do permission checks on the internal objects.
955 * Permissions are determined by the "owning" object.
957 if (IS_PRIVATE(inode))
960 return generic_permission(inode, mask);
963 static int xattr_hide_revalidate(struct dentry *dentry, unsigned int flags)
968 static const struct dentry_operations xattr_lookup_poison_ops = {
969 .d_revalidate = xattr_hide_revalidate,
972 int reiserfs_lookup_privroot(struct super_block *s)
974 struct dentry *dentry;
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 d_set_d_op(dentry, &xattr_lookup_poison_ops);
985 dentry->d_inode->i_flags |= S_PRIVATE;
987 err = PTR_ERR(dentry);
988 mutex_unlock(&s->s_root->d_inode->i_mutex);
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
998 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1001 struct dentry *privroot = REISERFS_SB(s)->priv_root;
1003 err = xattr_mount_check(s);
1007 if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
1008 mutex_lock(&s->s_root->d_inode->i_mutex);
1009 err = create_privroot(REISERFS_SB(s)->priv_root);
1010 mutex_unlock(&s->s_root->d_inode->i_mutex);
1013 if (privroot->d_inode) {
1014 s->s_xattr = reiserfs_xattr_handlers;
1015 mutex_lock(&privroot->d_inode->i_mutex);
1016 if (!REISERFS_SB(s)->xattr_root) {
1017 struct dentry *dentry;
1018 dentry = lookup_one_len(XAROOT_NAME, privroot,
1019 strlen(XAROOT_NAME));
1020 if (!IS_ERR(dentry))
1021 REISERFS_SB(s)->xattr_root = dentry;
1023 err = PTR_ERR(dentry);
1025 mutex_unlock(&privroot->d_inode->i_mutex);
1030 clear_bit(REISERFS_XATTRS_USER, &REISERFS_SB(s)->s_mount_opt);
1031 clear_bit(REISERFS_POSIXACL, &REISERFS_SB(s)->s_mount_opt);
1034 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1035 if (reiserfs_posixacl(s))
1036 s->s_flags |= MS_POSIXACL;
1038 s->s_flags &= ~MS_POSIXACL;