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.
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>
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>
51 #include <linux/security.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 return dir->i_op->create(dir, dentry, mode, NULL);
68 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode)
70 BUG_ON(!mutex_is_locked(&dir->i_mutex));
71 return dir->i_op->mkdir(dir, dentry, mode);
74 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
75 * mutation ops aren't called during rename or splace, which are the
76 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
77 * better than allocating another subclass just for this code. */
78 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
81 BUG_ON(!mutex_is_locked(&dir->i_mutex));
83 reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
84 I_MUTEX_CHILD, dir->i_sb);
85 error = dir->i_op->unlink(dir, dentry);
86 mutex_unlock(&dentry->d_inode->i_mutex);
93 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
96 BUG_ON(!mutex_is_locked(&dir->i_mutex));
98 reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
99 I_MUTEX_CHILD, dir->i_sb);
100 dentry_unhash(dentry);
101 error = dir->i_op->rmdir(dir, dentry);
103 dentry->d_inode->i_flags |= S_DEAD;
104 mutex_unlock(&dentry->d_inode->i_mutex);
112 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
114 static struct dentry *open_xa_root(struct super_block *sb, int flags)
116 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
117 struct dentry *xaroot;
118 if (!privroot->d_inode)
119 return ERR_PTR(-ENODATA);
121 mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
123 xaroot = dget(REISERFS_SB(sb)->xattr_root);
125 xaroot = ERR_PTR(-ENODATA);
126 else if (!xaroot->d_inode) {
128 if (xattr_may_create(flags))
129 err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
132 xaroot = ERR_PTR(err);
136 mutex_unlock(&privroot->d_inode->i_mutex);
140 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
142 struct dentry *xaroot, *xadir;
145 xaroot = open_xa_root(inode->i_sb, flags);
149 snprintf(namebuf, sizeof(namebuf), "%X.%X",
150 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
151 inode->i_generation);
153 mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
155 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
156 if (!IS_ERR(xadir) && !xadir->d_inode) {
158 if (xattr_may_create(flags))
159 err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
162 xadir = ERR_PTR(err);
166 mutex_unlock(&xaroot->d_inode->i_mutex);
171 /* The following are side effects of other operations that aren't explicitly
172 * modifying extended attributes. This includes operations such as permissions
173 * or ownership changes, object deletions, etc. */
174 struct reiserfs_dentry_buf {
175 struct dentry *xadir;
177 struct dentry *dentries[8];
181 fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
182 u64 ino, unsigned int d_type)
184 struct reiserfs_dentry_buf *dbuf = buf;
185 struct dentry *dentry;
186 WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
188 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
191 if (name[0] == '.' && (name[1] == '\0' ||
192 (name[1] == '.' && name[2] == '\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);
208 dbuf->dentries[dbuf->count++] = dentry;
213 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
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 *),
228 struct reiserfs_dentry_buf buf = {
232 /* Skip out, an xattr has no xattrs associated with it */
233 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
236 reiserfs_write_unlock(inode->i_sb);
237 dir = open_xa_dir(inode, XATTR_REPLACE);
240 reiserfs_write_lock(inode->i_sb);
242 } else if (!dir->d_inode) {
244 reiserfs_write_lock(inode->i_sb);
248 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
250 reiserfs_write_lock(inode->i_sb);
253 err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos);
254 while ((err == 0 || err == -ENOSPC) && buf.count) {
257 for (i = 0; i < buf.count && buf.dentries[i]; i++) {
259 struct dentry *dentry = buf.dentries[i];
261 if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode))
262 lerr = action(dentry, data);
265 buf.dentries[i] = NULL;
270 err = reiserfs_readdir_dentry(dir, &buf,
271 fill_with_dentries, &pos);
273 mutex_unlock(&dir->d_inode->i_mutex);
275 /* Clean up after a failed readdir */
276 cleanup_dentry_buf(&buf);
279 /* We start a transaction here to avoid a ABBA situation
280 * between the xattr root's i_mutex and the journal lock.
281 * This doesn't incur much additional overhead since the
282 * new transaction will just nest inside the
283 * outer transaction. */
284 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
285 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
286 struct reiserfs_transaction_handle th;
287 err = journal_begin(&th, inode->i_sb, blocks);
290 reiserfs_mutex_lock_nested_safe(
291 &dir->d_parent->d_inode->i_mutex,
292 I_MUTEX_XATTR, inode->i_sb);
293 err = action(dir, data);
294 jerror = journal_end(&th, inode->i_sb, blocks);
295 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
302 /* -ENODATA isn't an error */
308 static int delete_one_xattr(struct dentry *dentry, void *data)
310 struct inode *dir = dentry->d_parent->d_inode;
312 /* This is the xattr dir, handle specially. */
313 if (S_ISDIR(dentry->d_inode->i_mode))
314 return xattr_rmdir(dir, dentry);
316 return xattr_unlink(dir, dentry);
319 static int chown_one_xattr(struct dentry *dentry, void *data)
321 struct iattr *attrs = data;
322 return reiserfs_setattr(dentry, attrs);
325 /* No i_mutex, but the inode is unconnected. */
326 int reiserfs_delete_xattrs(struct inode *inode)
328 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
330 reiserfs_warning(inode->i_sb, "jdm-20004",
331 "Couldn't delete all xattrs (%d)\n", err);
335 /* inode->i_mutex: down */
336 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
338 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
340 reiserfs_warning(inode->i_sb, "jdm-20007",
341 "Couldn't chown all xattrs (%d)\n", err);
345 #ifdef CONFIG_REISERFS_FS_XATTR
346 /* Returns a dentry corresponding to a specific extended attribute file
347 * for the inode. If flags allow, the file is created. Otherwise, a
348 * valid or negative dentry, or an error is returned. */
349 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
352 struct dentry *xadir, *xafile;
355 xadir = open_xa_dir(inode, flags);
357 return ERR_CAST(xadir);
359 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
360 xafile = lookup_one_len(name, xadir, strlen(name));
361 if (IS_ERR(xafile)) {
362 err = PTR_ERR(xafile);
366 if (xafile->d_inode && (flags & XATTR_CREATE))
369 if (!xafile->d_inode) {
371 if (xattr_may_create(flags))
372 err = xattr_create(xadir->d_inode, xafile,
379 mutex_unlock(&xadir->d_inode->i_mutex);
386 /* Internal operations on file data */
387 static inline void reiserfs_put_page(struct page *page)
390 page_cache_release(page);
393 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
395 struct address_space *mapping = dir->i_mapping;
397 /* We can deadlock if we try to free dentries,
398 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
399 mapping_set_gfp_mask(mapping, GFP_NOFS);
400 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
409 reiserfs_put_page(page);
410 return ERR_PTR(-EIO);
413 static inline __u32 xattr_hash(const char *msg, int len)
415 return csum_partial(msg, len, 0);
418 int reiserfs_commit_write(struct file *f, struct page *page,
419 unsigned from, unsigned to);
420 int reiserfs_prepare_write(struct file *f, struct page *page,
421 unsigned from, unsigned to);
423 static void update_ctime(struct inode *inode)
425 struct timespec now = current_fs_time(inode->i_sb);
426 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
427 timespec_equal(&inode->i_ctime, &now))
430 inode->i_ctime = CURRENT_TIME_SEC;
431 mark_inode_dirty(inode);
434 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
437 struct dentry *dentry, *xadir;
439 xadir = open_xa_dir(inode, XATTR_REPLACE);
441 return PTR_ERR(xadir);
443 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
444 dentry = lookup_one_len(name, xadir, strlen(name));
445 if (IS_ERR(dentry)) {
446 err = PTR_ERR(dentry);
450 if (dentry->d_inode) {
451 reiserfs_write_lock(inode->i_sb);
452 err = xattr_unlink(xadir->d_inode, dentry);
453 reiserfs_write_unlock(inode->i_sb);
459 mutex_unlock(&xadir->d_inode->i_mutex);
465 /* Generic extended attribute operations that can be used by xa plugins */
468 * inode->i_mutex: down
471 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
472 struct inode *inode, const char *name,
473 const void *buffer, size_t buffer_size, int flags)
476 struct dentry *dentry;
480 size_t buffer_pos = 0;
484 if (get_inode_sd_version(inode) == STAT_DATA_V1)
487 reiserfs_write_unlock(inode->i_sb);
490 err = lookup_and_delete_xattr(inode, name);
491 reiserfs_write_lock(inode->i_sb);
495 dentry = xattr_lookup(inode, name, flags);
496 if (IS_ERR(dentry)) {
497 reiserfs_write_lock(inode->i_sb);
498 return PTR_ERR(dentry);
501 down_write(&REISERFS_I(inode)->i_xattr_sem);
503 reiserfs_write_lock(inode->i_sb);
505 xahash = xattr_hash(buffer, buffer_size);
506 while (buffer_pos < buffer_size || buffer_pos == 0) {
509 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
510 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
511 chunk = PAGE_CACHE_SIZE;
513 chunk = buffer_size - buffer_pos;
515 page = reiserfs_get_page(dentry->d_inode, file_pos);
522 data = page_address(page);
525 struct reiserfs_xattr_header *rxh;
526 skip = file_pos = sizeof(struct reiserfs_xattr_header);
527 if (chunk + skip > PAGE_CACHE_SIZE)
528 chunk = PAGE_CACHE_SIZE - skip;
529 rxh = (struct reiserfs_xattr_header *)data;
530 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
531 rxh->h_hash = cpu_to_le32(xahash);
534 err = reiserfs_prepare_write(NULL, page, page_offset,
535 page_offset + chunk + skip);
538 memcpy(data + skip, buffer + buffer_pos, chunk);
539 err = reiserfs_commit_write(NULL, page, page_offset,
540 page_offset + chunk +
544 reiserfs_put_page(page);
548 if (err || buffer_size == 0 || !buffer)
552 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
553 if (!err && new_size < i_size_read(dentry->d_inode)) {
554 struct iattr newattrs = {
555 .ia_ctime = current_fs_time(inode->i_sb),
556 .ia_size = buffer_size,
557 .ia_valid = ATTR_SIZE | ATTR_CTIME,
560 reiserfs_write_unlock(inode->i_sb);
561 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
562 down_write(&dentry->d_inode->i_alloc_sem);
563 reiserfs_write_lock(inode->i_sb);
565 err = reiserfs_setattr(dentry, &newattrs);
566 up_write(&dentry->d_inode->i_alloc_sem);
567 mutex_unlock(&dentry->d_inode->i_mutex);
571 up_write(&REISERFS_I(inode)->i_xattr_sem);
576 /* We need to start a transaction to maintain lock ordering */
577 int reiserfs_xattr_set(struct inode *inode, const char *name,
578 const void *buffer, size_t buffer_size, int flags)
581 struct reiserfs_transaction_handle th;
583 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
585 if (!(flags & XATTR_REPLACE))
586 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
588 reiserfs_write_lock(inode->i_sb);
589 error = journal_begin(&th, inode->i_sb, jbegin_count);
591 reiserfs_write_unlock(inode->i_sb);
595 error = reiserfs_xattr_set_handle(&th, inode, name,
596 buffer, buffer_size, flags);
598 error2 = journal_end(&th, inode->i_sb, jbegin_count);
601 reiserfs_write_unlock(inode->i_sb);
607 * inode->i_mutex: down
610 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
614 struct dentry *dentry;
617 size_t buffer_pos = 0;
624 /* We can't have xattrs attached to v1 items since they don't have
625 * generation numbers */
626 if (get_inode_sd_version(inode) == STAT_DATA_V1)
629 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
630 if (IS_ERR(dentry)) {
631 err = PTR_ERR(dentry);
635 down_read(&REISERFS_I(inode)->i_xattr_sem);
637 isize = i_size_read(dentry->d_inode);
639 /* Just return the size needed */
640 if (buffer == NULL) {
641 err = isize - sizeof(struct reiserfs_xattr_header);
645 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
650 while (file_pos < isize) {
654 if (isize - file_pos > PAGE_CACHE_SIZE)
655 chunk = PAGE_CACHE_SIZE;
657 chunk = isize - file_pos;
659 page = reiserfs_get_page(dentry->d_inode, file_pos);
666 data = page_address(page);
668 struct reiserfs_xattr_header *rxh =
669 (struct reiserfs_xattr_header *)data;
670 skip = file_pos = sizeof(struct reiserfs_xattr_header);
672 /* Magic doesn't match up.. */
673 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
675 reiserfs_put_page(page);
676 reiserfs_warning(inode->i_sb, "jdm-20001",
677 "Invalid magic for xattr (%s) "
678 "associated with %k", name,
683 hash = le32_to_cpu(rxh->h_hash);
685 memcpy(buffer + buffer_pos, data + skip, chunk);
687 reiserfs_put_page(page);
692 err = isize - sizeof(struct reiserfs_xattr_header);
694 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
696 reiserfs_warning(inode->i_sb, "jdm-20002",
697 "Invalid hash for xattr (%s) associated "
698 "with %k", name, INODE_PKEY(inode));
703 up_read(&REISERFS_I(inode)->i_xattr_sem);
711 * In order to implement different sets of xattr operations for each xattr
712 * prefix with the generic xattr API, a filesystem should create a
713 * null-terminated array of struct xattr_handler (one for each prefix) and
714 * hang a pointer to it off of the s_xattr field of the superblock.
716 * The generic_fooxattr() functions will use this list to dispatch xattr
717 * operations to the correct xattr_handler.
719 #define for_each_xattr_handler(handlers, handler) \
720 for ((handler) = *(handlers)++; \
722 (handler) = *(handlers)++)
724 /* This is the implementation for the xattr plugin infrastructure */
725 static inline struct xattr_handler *
726 find_xattr_handler_prefix(struct xattr_handler **handlers,
729 struct xattr_handler *xah;
734 for_each_xattr_handler(handlers, xah) {
735 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
744 * Inode operation getxattr()
747 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
750 struct xattr_handler *handler;
752 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
754 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
757 return handler->get(dentry, name, buffer, size, handler->flags);
761 * Inode operation setxattr()
763 * dentry->d_inode->i_mutex down
766 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
767 size_t size, int flags)
769 struct xattr_handler *handler;
771 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
773 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
776 return handler->set(dentry, name, value, size, flags, handler->flags);
780 * Inode operation removexattr()
782 * dentry->d_inode->i_mutex down
784 int reiserfs_removexattr(struct dentry *dentry, const char *name)
786 struct xattr_handler *handler;
787 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
789 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
792 return handler->set(dentry, name, NULL, 0, XATTR_REPLACE, handler->flags);
795 struct listxattr_buf {
799 struct dentry *dentry;
802 static int listxattr_filler(void *buf, const char *name, int namelen,
803 loff_t offset, u64 ino, unsigned int d_type)
805 struct listxattr_buf *b = (struct listxattr_buf *)buf;
807 if (name[0] != '.' ||
808 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
809 struct xattr_handler *handler;
810 handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr,
812 if (!handler) /* Unsupported xattr name */
815 size = handler->list(b->dentry, b->buf + b->pos,
816 b->size, name, namelen,
821 size = handler->list(b->dentry, NULL, 0, name,
822 namelen, handler->flags);
831 * Inode operation listxattr()
833 * We totally ignore the generic listxattr here because it would be stupid
834 * not to. Since the xattrs are organized in a directory, we can just
835 * readdir to find them.
837 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
842 struct listxattr_buf buf = {
845 .size = buffer ? size : 0,
848 if (!dentry->d_inode)
851 if (!dentry->d_sb->s_xattr ||
852 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
855 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
859 err = 0; /* Not an error if there aren't any xattrs */
863 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
864 err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos);
865 mutex_unlock(&dir->d_inode->i_mutex);
875 static int reiserfs_check_acl(struct inode *inode, int mask)
877 struct posix_acl *acl;
878 int error = -EAGAIN; /* do regular unix permission checks by default */
880 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
884 error = posix_acl_permission(inode, acl, mask);
885 posix_acl_release(acl);
886 } else if (PTR_ERR(acl) != -ENODATA)
887 error = PTR_ERR(acl);
893 static int create_privroot(struct dentry *dentry)
896 struct inode *inode = dentry->d_parent->d_inode;
897 WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
899 err = xattr_mkdir(inode, dentry, 0700);
900 if (err || !dentry->d_inode) {
901 reiserfs_warning(dentry->d_sb, "jdm-20006",
902 "xattrs/ACLs enabled and couldn't "
903 "find/create .reiserfs_priv. "
908 dentry->d_inode->i_flags |= S_PRIVATE;
909 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
910 "storage.\n", PRIVROOT_NAME);
916 int __init reiserfs_xattr_register_handlers(void) { return 0; }
917 void reiserfs_xattr_unregister_handlers(void) {}
918 static int create_privroot(struct dentry *dentry) { return 0; }
921 /* Actual operations that are exported to VFS-land */
922 struct xattr_handler *reiserfs_xattr_handlers[] = {
923 #ifdef CONFIG_REISERFS_FS_XATTR
924 &reiserfs_xattr_user_handler,
925 &reiserfs_xattr_trusted_handler,
927 #ifdef CONFIG_REISERFS_FS_SECURITY
928 &reiserfs_xattr_security_handler,
930 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
931 &reiserfs_posix_acl_access_handler,
932 &reiserfs_posix_acl_default_handler,
937 static int xattr_mount_check(struct super_block *s)
939 /* We need generation numbers to ensure that the oid mapping is correct
940 * v3.5 filesystems don't have them. */
941 if (old_format_only(s)) {
942 if (reiserfs_xattrs_optional(s)) {
943 /* Old format filesystem, but optional xattrs have
944 * been enabled. Error out. */
945 reiserfs_warning(s, "jdm-2005",
946 "xattrs/ACLs not supported "
947 "on pre-v3.6 format filesystems. "
956 int reiserfs_permission(struct inode *inode, int mask)
959 * We don't do permission checks on the internal objects.
960 * Permissions are determined by the "owning" object.
962 if (IS_PRIVATE(inode))
965 #ifdef CONFIG_REISERFS_FS_XATTR
967 * Stat data v1 doesn't support ACLs.
969 if (get_inode_sd_version(inode) != STAT_DATA_V1)
970 return generic_permission(inode, mask, reiserfs_check_acl);
972 return generic_permission(inode, mask, NULL);
975 /* This will catch lookups from the fs root to .reiserfs_priv */
977 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
979 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
980 if (container_of(q1, struct dentry, d_name) == priv_root)
982 if (q1->len == name->len &&
983 !memcmp(q1->name, name->name, name->len))
988 static const struct dentry_operations xattr_lookup_poison_ops = {
989 .d_compare = xattr_lookup_poison,
992 int reiserfs_lookup_privroot(struct super_block *s)
994 struct dentry *dentry;
997 /* If we don't have the privroot located yet - go find it */
998 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
999 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1000 strlen(PRIVROOT_NAME));
1001 if (!IS_ERR(dentry)) {
1002 REISERFS_SB(s)->priv_root = dentry;
1003 if (!reiserfs_expose_privroot(s))
1004 s->s_root->d_op = &xattr_lookup_poison_ops;
1005 if (dentry->d_inode)
1006 dentry->d_inode->i_flags |= S_PRIVATE;
1008 err = PTR_ERR(dentry);
1009 mutex_unlock(&s->s_root->d_inode->i_mutex);
1014 /* We need to take a copy of the mount flags since things like
1015 * MS_RDONLY don't get set until *after* we're called.
1016 * mount_flags != mount_options */
1017 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1020 struct dentry *privroot = REISERFS_SB(s)->priv_root;
1022 err = xattr_mount_check(s);
1026 if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
1027 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
1028 err = create_privroot(REISERFS_SB(s)->priv_root);
1029 mutex_unlock(&s->s_root->d_inode->i_mutex);
1032 if (privroot->d_inode) {
1033 s->s_xattr = reiserfs_xattr_handlers;
1034 reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
1035 if (!REISERFS_SB(s)->xattr_root) {
1036 struct dentry *dentry;
1037 dentry = lookup_one_len(XAROOT_NAME, privroot,
1038 strlen(XAROOT_NAME));
1039 if (!IS_ERR(dentry))
1040 REISERFS_SB(s)->xattr_root = dentry;
1042 err = PTR_ERR(dentry);
1044 mutex_unlock(&privroot->d_inode->i_mutex);
1049 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1050 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1053 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1054 if (reiserfs_posixacl(s))
1055 s->s_flags |= MS_POSIXACL;
1057 s->s_flags &= ~MS_POSIXACL;