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>
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));
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));
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)
82 BUG_ON(!mutex_is_locked(&dir->i_mutex));
85 reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
86 I_MUTEX_CHILD, dir->i_sb);
87 error = dir->i_op->unlink(dir, dentry);
88 mutex_unlock(&dentry->d_inode->i_mutex);
95 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
98 BUG_ON(!mutex_is_locked(&dir->i_mutex));
101 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
102 dentry_unhash(dentry);
103 error = dir->i_op->rmdir(dir, dentry);
105 dentry->d_inode->i_flags |= S_DEAD;
106 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);
173 /* The following are side effects of other operations that aren't explicitly
174 * modifying extended attributes. This includes operations such as permissions
175 * or ownership changes, object deletions, etc. */
176 struct reiserfs_dentry_buf {
177 struct dentry *xadir;
179 struct dentry *dentries[8];
183 fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
184 u64 ino, unsigned int d_type)
186 struct reiserfs_dentry_buf *dbuf = buf;
187 struct dentry *dentry;
188 WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
190 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
193 if (name[0] == '.' && (name[1] == '\0' ||
194 (name[1] == '.' && name[2] == '\0')))
197 dentry = lookup_one_len(name, dbuf->xadir, namelen);
198 if (IS_ERR(dentry)) {
199 return PTR_ERR(dentry);
200 } else if (!dentry->d_inode) {
201 /* A directory entry exists, but no file? */
202 reiserfs_error(dentry->d_sb, "xattr-20003",
203 "Corrupted directory: xattr %s listed but "
204 "not found for file %s.\n",
205 dentry->d_name.name, dbuf->xadir->d_name.name);
210 dbuf->dentries[dbuf->count++] = dentry;
215 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
218 for (i = 0; i < buf->count; i++)
219 if (buf->dentries[i])
220 dput(buf->dentries[i]);
223 static int reiserfs_for_each_xattr(struct inode *inode,
224 int (*action)(struct dentry *, void *),
230 struct reiserfs_dentry_buf buf = {
234 /* Skip out, an xattr has no xattrs associated with it */
235 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
238 reiserfs_write_unlock(inode->i_sb);
239 dir = open_xa_dir(inode, XATTR_REPLACE);
242 reiserfs_write_lock(inode->i_sb);
244 } else if (!dir->d_inode) {
246 reiserfs_write_lock(inode->i_sb);
250 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
252 reiserfs_write_lock(inode->i_sb);
255 err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos);
256 while ((err == 0 || err == -ENOSPC) && buf.count) {
259 for (i = 0; i < buf.count && buf.dentries[i]; i++) {
261 struct dentry *dentry = buf.dentries[i];
263 if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode))
264 lerr = action(dentry, data);
267 buf.dentries[i] = NULL;
272 err = reiserfs_readdir_dentry(dir, &buf,
273 fill_with_dentries, &pos);
275 mutex_unlock(&dir->d_inode->i_mutex);
277 /* Clean up after a failed readdir */
278 cleanup_dentry_buf(&buf);
281 /* We start a transaction here to avoid a ABBA situation
282 * between the xattr root's i_mutex and the journal lock.
283 * This doesn't incur much additional overhead since the
284 * new transaction will just nest inside the
285 * outer transaction. */
286 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
287 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
288 struct reiserfs_transaction_handle th;
289 err = journal_begin(&th, inode->i_sb, blocks);
292 mutex_lock_nested(&dir->d_parent->d_inode->i_mutex,
294 err = action(dir, data);
295 jerror = journal_end(&th, inode->i_sb, blocks);
296 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
303 /* -ENODATA isn't an error */
309 static int delete_one_xattr(struct dentry *dentry, void *data)
311 struct inode *dir = dentry->d_parent->d_inode;
313 /* This is the xattr dir, handle specially. */
314 if (S_ISDIR(dentry->d_inode->i_mode))
315 return xattr_rmdir(dir, dentry);
317 return xattr_unlink(dir, dentry);
320 static int chown_one_xattr(struct dentry *dentry, void *data)
322 struct iattr *attrs = data;
323 return reiserfs_setattr(dentry, attrs);
326 /* No i_mutex, but the inode is unconnected. */
327 int reiserfs_delete_xattrs(struct inode *inode)
329 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
331 reiserfs_warning(inode->i_sb, "jdm-20004",
332 "Couldn't delete all xattrs (%d)\n", err);
336 /* inode->i_mutex: down */
337 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
339 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
341 reiserfs_warning(inode->i_sb, "jdm-20007",
342 "Couldn't chown all xattrs (%d)\n", err);
346 #ifdef CONFIG_REISERFS_FS_XATTR
347 /* Returns a dentry corresponding to a specific extended attribute file
348 * for the inode. If flags allow, the file is created. Otherwise, a
349 * valid or negative dentry, or an error is returned. */
350 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
353 struct dentry *xadir, *xafile;
356 xadir = open_xa_dir(inode, flags);
358 return ERR_CAST(xadir);
360 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
361 xafile = lookup_one_len(name, xadir, strlen(name));
362 if (IS_ERR(xafile)) {
363 err = PTR_ERR(xafile);
367 if (xafile->d_inode && (flags & XATTR_CREATE))
370 if (!xafile->d_inode) {
372 if (xattr_may_create(flags))
373 err = xattr_create(xadir->d_inode, xafile,
380 mutex_unlock(&xadir->d_inode->i_mutex);
387 /* Internal operations on file data */
388 static inline void reiserfs_put_page(struct page *page)
391 page_cache_release(page);
394 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
396 struct address_space *mapping = dir->i_mapping;
398 /* We can deadlock if we try to free dentries,
399 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
400 mapping_set_gfp_mask(mapping, GFP_NOFS);
401 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
410 reiserfs_put_page(page);
411 return ERR_PTR(-EIO);
414 static inline __u32 xattr_hash(const char *msg, int len)
416 return csum_partial(msg, len, 0);
419 int reiserfs_commit_write(struct file *f, struct page *page,
420 unsigned from, unsigned to);
421 int reiserfs_prepare_write(struct file *f, struct page *page,
422 unsigned from, unsigned to);
424 static void update_ctime(struct inode *inode)
426 struct timespec now = current_fs_time(inode->i_sb);
427 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
428 timespec_equal(&inode->i_ctime, &now))
431 inode->i_ctime = CURRENT_TIME_SEC;
432 mark_inode_dirty(inode);
435 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
438 struct dentry *dentry, *xadir;
440 xadir = open_xa_dir(inode, XATTR_REPLACE);
442 return PTR_ERR(xadir);
444 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
445 dentry = lookup_one_len(name, xadir, strlen(name));
446 if (IS_ERR(dentry)) {
447 err = PTR_ERR(dentry);
451 if (dentry->d_inode) {
452 err = xattr_unlink(xadir->d_inode, dentry);
458 mutex_unlock(&xadir->d_inode->i_mutex);
464 /* Generic extended attribute operations that can be used by xa plugins */
467 * inode->i_mutex: down
470 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
471 struct inode *inode, const char *name,
472 const void *buffer, size_t buffer_size, int flags)
475 struct dentry *dentry;
479 size_t buffer_pos = 0;
483 if (get_inode_sd_version(inode) == STAT_DATA_V1)
487 return lookup_and_delete_xattr(inode, name);
489 reiserfs_write_unlock(inode->i_sb);
490 dentry = xattr_lookup(inode, name, flags);
491 if (IS_ERR(dentry)) {
492 reiserfs_write_lock(inode->i_sb);
493 return PTR_ERR(dentry);
496 down_read(&REISERFS_I(inode)->i_xattr_sem);
498 reiserfs_write_lock(inode->i_sb);
500 xahash = xattr_hash(buffer, buffer_size);
501 while (buffer_pos < buffer_size || buffer_pos == 0) {
504 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
505 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
506 chunk = PAGE_CACHE_SIZE;
508 chunk = buffer_size - buffer_pos;
510 page = reiserfs_get_page(dentry->d_inode, file_pos);
517 data = page_address(page);
520 struct reiserfs_xattr_header *rxh;
521 skip = file_pos = sizeof(struct reiserfs_xattr_header);
522 if (chunk + skip > PAGE_CACHE_SIZE)
523 chunk = PAGE_CACHE_SIZE - skip;
524 rxh = (struct reiserfs_xattr_header *)data;
525 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
526 rxh->h_hash = cpu_to_le32(xahash);
529 err = reiserfs_prepare_write(NULL, page, page_offset,
530 page_offset + chunk + skip);
533 memcpy(data + skip, buffer + buffer_pos, chunk);
534 err = reiserfs_commit_write(NULL, page, page_offset,
535 page_offset + chunk +
539 reiserfs_put_page(page);
543 if (err || buffer_size == 0 || !buffer)
547 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
548 if (!err && new_size < i_size_read(dentry->d_inode)) {
549 struct iattr newattrs = {
550 .ia_ctime = current_fs_time(inode->i_sb),
551 .ia_size = buffer_size,
552 .ia_valid = ATTR_SIZE | ATTR_CTIME,
554 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
555 down_write(&dentry->d_inode->i_alloc_sem);
556 err = reiserfs_setattr(dentry, &newattrs);
557 up_write(&dentry->d_inode->i_alloc_sem);
558 mutex_unlock(&dentry->d_inode->i_mutex);
562 up_write(&REISERFS_I(inode)->i_xattr_sem);
567 /* We need to start a transaction to maintain lock ordering */
568 int reiserfs_xattr_set(struct inode *inode, const char *name,
569 const void *buffer, size_t buffer_size, int flags)
572 struct reiserfs_transaction_handle th;
574 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
576 if (!(flags & XATTR_REPLACE))
577 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
579 reiserfs_write_lock(inode->i_sb);
580 error = journal_begin(&th, inode->i_sb, jbegin_count);
582 reiserfs_write_unlock(inode->i_sb);
586 error = reiserfs_xattr_set_handle(&th, inode, name,
587 buffer, buffer_size, flags);
589 error2 = journal_end(&th, inode->i_sb, jbegin_count);
592 reiserfs_write_unlock(inode->i_sb);
598 * inode->i_mutex: down
601 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
605 struct dentry *dentry;
608 size_t buffer_pos = 0;
615 /* We can't have xattrs attached to v1 items since they don't have
616 * generation numbers */
617 if (get_inode_sd_version(inode) == STAT_DATA_V1)
620 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
621 if (IS_ERR(dentry)) {
622 err = PTR_ERR(dentry);
626 down_read(&REISERFS_I(inode)->i_xattr_sem);
628 isize = i_size_read(dentry->d_inode);
630 /* Just return the size needed */
631 if (buffer == NULL) {
632 err = isize - sizeof(struct reiserfs_xattr_header);
636 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
641 while (file_pos < isize) {
645 if (isize - file_pos > PAGE_CACHE_SIZE)
646 chunk = PAGE_CACHE_SIZE;
648 chunk = isize - file_pos;
650 page = reiserfs_get_page(dentry->d_inode, file_pos);
657 data = page_address(page);
659 struct reiserfs_xattr_header *rxh =
660 (struct reiserfs_xattr_header *)data;
661 skip = file_pos = sizeof(struct reiserfs_xattr_header);
663 /* Magic doesn't match up.. */
664 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
666 reiserfs_put_page(page);
667 reiserfs_warning(inode->i_sb, "jdm-20001",
668 "Invalid magic for xattr (%s) "
669 "associated with %k", name,
674 hash = le32_to_cpu(rxh->h_hash);
676 memcpy(buffer + buffer_pos, data + skip, chunk);
678 reiserfs_put_page(page);
683 err = isize - sizeof(struct reiserfs_xattr_header);
685 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
687 reiserfs_warning(inode->i_sb, "jdm-20002",
688 "Invalid hash for xattr (%s) associated "
689 "with %k", name, INODE_PKEY(inode));
694 up_read(&REISERFS_I(inode)->i_xattr_sem);
702 * In order to implement different sets of xattr operations for each xattr
703 * prefix with the generic xattr API, a filesystem should create a
704 * null-terminated array of struct xattr_handler (one for each prefix) and
705 * hang a pointer to it off of the s_xattr field of the superblock.
707 * The generic_fooxattr() functions will use this list to dispatch xattr
708 * operations to the correct xattr_handler.
710 #define for_each_xattr_handler(handlers, handler) \
711 for ((handler) = *(handlers)++; \
713 (handler) = *(handlers)++)
715 /* This is the implementation for the xattr plugin infrastructure */
716 static inline struct xattr_handler *
717 find_xattr_handler_prefix(struct xattr_handler **handlers,
720 struct xattr_handler *xah;
725 for_each_xattr_handler(handlers, xah) {
726 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
735 * Inode operation getxattr()
738 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
741 struct inode *inode = dentry->d_inode;
742 struct xattr_handler *handler;
744 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
746 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
749 return handler->get(inode, name, buffer, size);
753 * Inode operation setxattr()
755 * dentry->d_inode->i_mutex down
758 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
759 size_t size, int flags)
761 struct inode *inode = dentry->d_inode;
762 struct xattr_handler *handler;
764 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
766 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
769 return handler->set(inode, name, value, size, flags);
773 * Inode operation removexattr()
775 * dentry->d_inode->i_mutex down
777 int reiserfs_removexattr(struct dentry *dentry, const char *name)
779 struct inode *inode = dentry->d_inode;
780 struct xattr_handler *handler;
781 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
783 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
786 return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
789 struct listxattr_buf {
796 static int listxattr_filler(void *buf, const char *name, int namelen,
797 loff_t offset, u64 ino, unsigned int d_type)
799 struct listxattr_buf *b = (struct listxattr_buf *)buf;
801 if (name[0] != '.' ||
802 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
803 struct xattr_handler *handler;
804 handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
806 if (!handler) /* Unsupported xattr name */
809 size = handler->list(b->inode, b->buf + b->pos,
810 b->size, name, namelen);
814 size = handler->list(b->inode, NULL, 0, name, namelen);
823 * Inode operation listxattr()
825 * We totally ignore the generic listxattr here because it would be stupid
826 * not to. Since the xattrs are organized in a directory, we can just
827 * readdir to find them.
829 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
834 struct listxattr_buf buf = {
835 .inode = dentry->d_inode,
837 .size = buffer ? size : 0,
840 if (!dentry->d_inode)
843 if (!dentry->d_sb->s_xattr ||
844 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
847 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
851 err = 0; /* Not an error if there aren't any xattrs */
855 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
856 err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos);
857 mutex_unlock(&dir->d_inode->i_mutex);
867 static int reiserfs_check_acl(struct inode *inode, int mask)
869 struct posix_acl *acl;
870 int error = -EAGAIN; /* do regular unix permission checks by default */
872 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
876 error = posix_acl_permission(inode, acl, mask);
877 posix_acl_release(acl);
878 } else if (PTR_ERR(acl) != -ENODATA)
879 error = PTR_ERR(acl);
885 static int create_privroot(struct dentry *dentry)
888 struct inode *inode = dentry->d_parent->d_inode;
889 WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
891 err = xattr_mkdir(inode, dentry, 0700);
892 if (err || !dentry->d_inode) {
893 reiserfs_warning(dentry->d_sb, "jdm-20006",
894 "xattrs/ACLs enabled and couldn't "
895 "find/create .reiserfs_priv. "
900 dentry->d_inode->i_flags |= S_PRIVATE;
901 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
902 "storage.\n", PRIVROOT_NAME);
908 int __init reiserfs_xattr_register_handlers(void) { return 0; }
909 void reiserfs_xattr_unregister_handlers(void) {}
910 static int create_privroot(struct dentry *dentry) { return 0; }
913 /* Actual operations that are exported to VFS-land */
914 struct xattr_handler *reiserfs_xattr_handlers[] = {
915 #ifdef CONFIG_REISERFS_FS_XATTR
916 &reiserfs_xattr_user_handler,
917 &reiserfs_xattr_trusted_handler,
919 #ifdef CONFIG_REISERFS_FS_SECURITY
920 &reiserfs_xattr_security_handler,
922 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
923 &reiserfs_posix_acl_access_handler,
924 &reiserfs_posix_acl_default_handler,
929 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. */
933 if (old_format_only(s)) {
934 if (reiserfs_xattrs_optional(s)) {
935 /* Old format filesystem, but optional xattrs have
936 * been enabled. Error out. */
937 reiserfs_warning(s, "jdm-2005",
938 "xattrs/ACLs not supported "
939 "on pre-v3.6 format filesystems. "
948 int reiserfs_permission(struct inode *inode, int mask)
951 * We don't do permission checks on the internal objects.
952 * Permissions are determined by the "owning" object.
954 if (IS_PRIVATE(inode))
957 #ifdef CONFIG_REISERFS_FS_XATTR
959 * Stat data v1 doesn't support ACLs.
961 if (get_inode_sd_version(inode) != STAT_DATA_V1)
962 return generic_permission(inode, mask, reiserfs_check_acl);
964 return generic_permission(inode, mask, NULL);
967 /* This will catch lookups from the fs root to .reiserfs_priv */
969 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
971 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
972 if (container_of(q1, struct dentry, d_name) == priv_root)
974 if (q1->len == name->len &&
975 !memcmp(q1->name, name->name, name->len))
980 static const struct dentry_operations xattr_lookup_poison_ops = {
981 .d_compare = xattr_lookup_poison,
984 int reiserfs_lookup_privroot(struct super_block *s)
986 struct dentry *dentry;
989 /* If we don't have the privroot located yet - go find it */
990 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
991 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
992 strlen(PRIVROOT_NAME));
993 if (!IS_ERR(dentry)) {
994 REISERFS_SB(s)->priv_root = dentry;
995 if (!reiserfs_expose_privroot(s))
996 s->s_root->d_op = &xattr_lookup_poison_ops;
998 dentry->d_inode->i_flags |= S_PRIVATE;
1000 err = PTR_ERR(dentry);
1001 mutex_unlock(&s->s_root->d_inode->i_mutex);
1006 /* We need to take a copy of the mount flags since things like
1007 * MS_RDONLY don't get set until *after* we're called.
1008 * mount_flags != mount_options */
1009 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1012 struct dentry *privroot = REISERFS_SB(s)->priv_root;
1014 err = xattr_mount_check(s);
1018 if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
1019 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
1020 err = create_privroot(REISERFS_SB(s)->priv_root);
1021 mutex_unlock(&s->s_root->d_inode->i_mutex);
1024 if (privroot->d_inode) {
1025 s->s_xattr = reiserfs_xattr_handlers;
1026 reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
1027 if (!REISERFS_SB(s)->xattr_root) {
1028 struct dentry *dentry;
1029 dentry = lookup_one_len(XAROOT_NAME, privroot,
1030 strlen(XAROOT_NAME));
1031 if (!IS_ERR(dentry))
1032 REISERFS_SB(s)->xattr_root = dentry;
1034 err = PTR_ERR(dentry);
1036 mutex_unlock(&privroot->d_inode->i_mutex);
1041 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1042 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1045 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1046 if (reiserfs_posixacl(s))
1047 s->s_flags |= MS_POSIXACL;
1049 s->s_flags &= ~MS_POSIXACL;