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 reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
102 I_MUTEX_CHILD, dir->i_sb);
103 dentry_unhash(dentry);
104 error = dir->i_op->rmdir(dir, dentry);
106 dentry->d_inode->i_flags |= S_DEAD;
107 mutex_unlock(&dentry->d_inode->i_mutex);
115 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
117 static struct dentry *open_xa_root(struct super_block *sb, int flags)
119 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
120 struct dentry *xaroot;
121 if (!privroot->d_inode)
122 return ERR_PTR(-ENODATA);
124 mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
126 xaroot = dget(REISERFS_SB(sb)->xattr_root);
128 xaroot = ERR_PTR(-ENODATA);
129 else if (!xaroot->d_inode) {
131 if (xattr_may_create(flags))
132 err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
135 xaroot = ERR_PTR(err);
139 mutex_unlock(&privroot->d_inode->i_mutex);
143 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
145 struct dentry *xaroot, *xadir;
148 xaroot = open_xa_root(inode->i_sb, flags);
152 snprintf(namebuf, sizeof(namebuf), "%X.%X",
153 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
154 inode->i_generation);
156 mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
158 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
159 if (!IS_ERR(xadir) && !xadir->d_inode) {
161 if (xattr_may_create(flags))
162 err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
165 xadir = ERR_PTR(err);
169 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. */
177 struct reiserfs_dentry_buf {
178 struct dentry *xadir;
180 struct dentry *dentries[8];
184 fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
185 u64 ino, unsigned int d_type)
187 struct reiserfs_dentry_buf *dbuf = buf;
188 struct dentry *dentry;
189 WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
191 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
194 if (name[0] == '.' && (name[1] == '\0' ||
195 (name[1] == '.' && name[2] == '\0')))
198 dentry = lookup_one_len(name, dbuf->xadir, namelen);
199 if (IS_ERR(dentry)) {
200 return PTR_ERR(dentry);
201 } else if (!dentry->d_inode) {
202 /* A directory entry exists, but no file? */
203 reiserfs_error(dentry->d_sb, "xattr-20003",
204 "Corrupted directory: xattr %s listed but "
205 "not found for file %s.\n",
206 dentry->d_name.name, dbuf->xadir->d_name.name);
211 dbuf->dentries[dbuf->count++] = dentry;
216 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
219 for (i = 0; i < buf->count; i++)
220 if (buf->dentries[i])
221 dput(buf->dentries[i]);
224 static int reiserfs_for_each_xattr(struct inode *inode,
225 int (*action)(struct dentry *, void *),
231 struct reiserfs_dentry_buf buf = {
235 /* Skip out, an xattr has no xattrs associated with it */
236 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
239 reiserfs_write_unlock(inode->i_sb);
240 dir = open_xa_dir(inode, XATTR_REPLACE);
243 reiserfs_write_lock(inode->i_sb);
245 } else if (!dir->d_inode) {
247 reiserfs_write_lock(inode->i_sb);
251 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
253 reiserfs_write_lock(inode->i_sb);
256 err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos);
257 while ((err == 0 || err == -ENOSPC) && buf.count) {
260 for (i = 0; i < buf.count && buf.dentries[i]; i++) {
262 struct dentry *dentry = buf.dentries[i];
264 if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode))
265 lerr = action(dentry, data);
268 buf.dentries[i] = NULL;
273 err = reiserfs_readdir_dentry(dir, &buf,
274 fill_with_dentries, &pos);
276 mutex_unlock(&dir->d_inode->i_mutex);
278 /* Clean up after a failed readdir */
279 cleanup_dentry_buf(&buf);
282 /* We start a transaction here to avoid a ABBA situation
283 * between the xattr root's i_mutex and the journal lock.
284 * This doesn't incur much additional overhead since the
285 * new transaction will just nest inside the
286 * outer transaction. */
287 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
288 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
289 struct reiserfs_transaction_handle th;
290 err = journal_begin(&th, inode->i_sb, blocks);
293 reiserfs_mutex_lock_nested_safe(
294 &dir->d_parent->d_inode->i_mutex,
295 I_MUTEX_XATTR, inode->i_sb);
296 err = action(dir, data);
297 jerror = journal_end(&th, inode->i_sb, blocks);
298 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
305 /* -ENODATA isn't an error */
311 static int delete_one_xattr(struct dentry *dentry, void *data)
313 struct inode *dir = dentry->d_parent->d_inode;
315 /* This is the xattr dir, handle specially. */
316 if (S_ISDIR(dentry->d_inode->i_mode))
317 return xattr_rmdir(dir, dentry);
319 return xattr_unlink(dir, dentry);
322 static int chown_one_xattr(struct dentry *dentry, void *data)
324 struct iattr *attrs = data;
325 return reiserfs_setattr(dentry, attrs);
328 /* No i_mutex, but the inode is unconnected. */
329 int reiserfs_delete_xattrs(struct inode *inode)
331 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
333 reiserfs_warning(inode->i_sb, "jdm-20004",
334 "Couldn't delete all xattrs (%d)\n", err);
338 /* inode->i_mutex: down */
339 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
341 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
343 reiserfs_warning(inode->i_sb, "jdm-20007",
344 "Couldn't chown all xattrs (%d)\n", err);
348 #ifdef CONFIG_REISERFS_FS_XATTR
349 /* Returns a dentry corresponding to a specific extended attribute file
350 * for the inode. If flags allow, the file is created. Otherwise, a
351 * valid or negative dentry, or an error is returned. */
352 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
355 struct dentry *xadir, *xafile;
358 xadir = open_xa_dir(inode, flags);
360 return ERR_CAST(xadir);
362 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
363 xafile = lookup_one_len(name, xadir, strlen(name));
364 if (IS_ERR(xafile)) {
365 err = PTR_ERR(xafile);
369 if (xafile->d_inode && (flags & XATTR_CREATE))
372 if (!xafile->d_inode) {
374 if (xattr_may_create(flags))
375 err = xattr_create(xadir->d_inode, xafile,
382 mutex_unlock(&xadir->d_inode->i_mutex);
389 /* Internal operations on file data */
390 static inline void reiserfs_put_page(struct page *page)
393 page_cache_release(page);
396 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
398 struct address_space *mapping = dir->i_mapping;
400 /* We can deadlock if we try to free dentries,
401 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
402 mapping_set_gfp_mask(mapping, GFP_NOFS);
403 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
412 reiserfs_put_page(page);
413 return ERR_PTR(-EIO);
416 static inline __u32 xattr_hash(const char *msg, int len)
418 return csum_partial(msg, len, 0);
421 int reiserfs_commit_write(struct file *f, struct page *page,
422 unsigned from, unsigned to);
423 int reiserfs_prepare_write(struct file *f, struct page *page,
424 unsigned from, unsigned to);
426 static void update_ctime(struct inode *inode)
428 struct timespec now = current_fs_time(inode->i_sb);
429 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
430 timespec_equal(&inode->i_ctime, &now))
433 inode->i_ctime = CURRENT_TIME_SEC;
434 mark_inode_dirty(inode);
437 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
440 struct dentry *dentry, *xadir;
442 xadir = open_xa_dir(inode, XATTR_REPLACE);
444 return PTR_ERR(xadir);
446 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
447 dentry = lookup_one_len(name, xadir, strlen(name));
448 if (IS_ERR(dentry)) {
449 err = PTR_ERR(dentry);
453 if (dentry->d_inode) {
454 err = xattr_unlink(xadir->d_inode, dentry);
460 mutex_unlock(&xadir->d_inode->i_mutex);
466 /* Generic extended attribute operations that can be used by xa plugins */
469 * inode->i_mutex: down
472 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
473 struct inode *inode, const char *name,
474 const void *buffer, size_t buffer_size, int flags)
477 struct dentry *dentry;
481 size_t buffer_pos = 0;
485 if (get_inode_sd_version(inode) == STAT_DATA_V1)
489 return lookup_and_delete_xattr(inode, name);
491 reiserfs_write_unlock(inode->i_sb);
492 dentry = xattr_lookup(inode, name, flags);
493 if (IS_ERR(dentry)) {
494 reiserfs_write_lock(inode->i_sb);
495 return PTR_ERR(dentry);
498 down_write(&REISERFS_I(inode)->i_xattr_sem);
500 reiserfs_write_lock(inode->i_sb);
502 xahash = xattr_hash(buffer, buffer_size);
503 while (buffer_pos < buffer_size || buffer_pos == 0) {
506 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
507 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
508 chunk = PAGE_CACHE_SIZE;
510 chunk = buffer_size - buffer_pos;
512 page = reiserfs_get_page(dentry->d_inode, file_pos);
519 data = page_address(page);
522 struct reiserfs_xattr_header *rxh;
523 skip = file_pos = sizeof(struct reiserfs_xattr_header);
524 if (chunk + skip > PAGE_CACHE_SIZE)
525 chunk = PAGE_CACHE_SIZE - skip;
526 rxh = (struct reiserfs_xattr_header *)data;
527 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
528 rxh->h_hash = cpu_to_le32(xahash);
531 err = reiserfs_prepare_write(NULL, page, page_offset,
532 page_offset + chunk + skip);
535 memcpy(data + skip, buffer + buffer_pos, chunk);
536 err = reiserfs_commit_write(NULL, page, page_offset,
537 page_offset + chunk +
541 reiserfs_put_page(page);
545 if (err || buffer_size == 0 || !buffer)
549 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
550 if (!err && new_size < i_size_read(dentry->d_inode)) {
551 struct iattr newattrs = {
552 .ia_ctime = current_fs_time(inode->i_sb),
553 .ia_size = buffer_size,
554 .ia_valid = ATTR_SIZE | ATTR_CTIME,
556 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
557 down_write(&dentry->d_inode->i_alloc_sem);
558 err = reiserfs_setattr(dentry, &newattrs);
559 up_write(&dentry->d_inode->i_alloc_sem);
560 mutex_unlock(&dentry->d_inode->i_mutex);
564 up_write(&REISERFS_I(inode)->i_xattr_sem);
569 /* We need to start a transaction to maintain lock ordering */
570 int reiserfs_xattr_set(struct inode *inode, const char *name,
571 const void *buffer, size_t buffer_size, int flags)
574 struct reiserfs_transaction_handle th;
576 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
578 if (!(flags & XATTR_REPLACE))
579 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
581 reiserfs_write_lock(inode->i_sb);
582 error = journal_begin(&th, inode->i_sb, jbegin_count);
584 reiserfs_write_unlock(inode->i_sb);
588 error = reiserfs_xattr_set_handle(&th, inode, name,
589 buffer, buffer_size, flags);
591 error2 = journal_end(&th, inode->i_sb, jbegin_count);
594 reiserfs_write_unlock(inode->i_sb);
600 * inode->i_mutex: down
603 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
607 struct dentry *dentry;
610 size_t buffer_pos = 0;
617 /* We can't have xattrs attached to v1 items since they don't have
618 * generation numbers */
619 if (get_inode_sd_version(inode) == STAT_DATA_V1)
622 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
623 if (IS_ERR(dentry)) {
624 err = PTR_ERR(dentry);
628 down_read(&REISERFS_I(inode)->i_xattr_sem);
630 isize = i_size_read(dentry->d_inode);
632 /* Just return the size needed */
633 if (buffer == NULL) {
634 err = isize - sizeof(struct reiserfs_xattr_header);
638 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
643 while (file_pos < isize) {
647 if (isize - file_pos > PAGE_CACHE_SIZE)
648 chunk = PAGE_CACHE_SIZE;
650 chunk = isize - file_pos;
652 page = reiserfs_get_page(dentry->d_inode, file_pos);
659 data = page_address(page);
661 struct reiserfs_xattr_header *rxh =
662 (struct reiserfs_xattr_header *)data;
663 skip = file_pos = sizeof(struct reiserfs_xattr_header);
665 /* Magic doesn't match up.. */
666 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
668 reiserfs_put_page(page);
669 reiserfs_warning(inode->i_sb, "jdm-20001",
670 "Invalid magic for xattr (%s) "
671 "associated with %k", name,
676 hash = le32_to_cpu(rxh->h_hash);
678 memcpy(buffer + buffer_pos, data + skip, chunk);
680 reiserfs_put_page(page);
685 err = isize - sizeof(struct reiserfs_xattr_header);
687 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
689 reiserfs_warning(inode->i_sb, "jdm-20002",
690 "Invalid hash for xattr (%s) associated "
691 "with %k", name, INODE_PKEY(inode));
696 up_read(&REISERFS_I(inode)->i_xattr_sem);
704 * In order to implement different sets of xattr operations for each xattr
705 * prefix with the generic xattr API, a filesystem should create a
706 * null-terminated array of struct xattr_handler (one for each prefix) and
707 * hang a pointer to it off of the s_xattr field of the superblock.
709 * The generic_fooxattr() functions will use this list to dispatch xattr
710 * operations to the correct xattr_handler.
712 #define for_each_xattr_handler(handlers, handler) \
713 for ((handler) = *(handlers)++; \
715 (handler) = *(handlers)++)
717 /* This is the implementation for the xattr plugin infrastructure */
718 static inline struct xattr_handler *
719 find_xattr_handler_prefix(struct xattr_handler **handlers,
722 struct xattr_handler *xah;
727 for_each_xattr_handler(handlers, xah) {
728 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
737 * Inode operation getxattr()
740 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
743 struct inode *inode = dentry->d_inode;
744 struct xattr_handler *handler;
746 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
748 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
751 return handler->get(inode, name, buffer, size);
755 * Inode operation setxattr()
757 * dentry->d_inode->i_mutex down
760 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
761 size_t size, int flags)
763 struct inode *inode = dentry->d_inode;
764 struct xattr_handler *handler;
766 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
768 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
771 return handler->set(inode, name, value, size, flags);
775 * Inode operation removexattr()
777 * dentry->d_inode->i_mutex down
779 int reiserfs_removexattr(struct dentry *dentry, const char *name)
781 struct inode *inode = dentry->d_inode;
782 struct xattr_handler *handler;
783 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
785 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
788 return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
791 struct listxattr_buf {
798 static int listxattr_filler(void *buf, const char *name, int namelen,
799 loff_t offset, u64 ino, unsigned int d_type)
801 struct listxattr_buf *b = (struct listxattr_buf *)buf;
803 if (name[0] != '.' ||
804 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
805 struct xattr_handler *handler;
806 handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
808 if (!handler) /* Unsupported xattr name */
811 size = handler->list(b->inode, b->buf + b->pos,
812 b->size, name, namelen);
816 size = handler->list(b->inode, NULL, 0, name, namelen);
825 * Inode operation listxattr()
827 * We totally ignore the generic listxattr here because it would be stupid
828 * not to. Since the xattrs are organized in a directory, we can just
829 * readdir to find them.
831 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
836 struct listxattr_buf buf = {
837 .inode = dentry->d_inode,
839 .size = buffer ? size : 0,
842 if (!dentry->d_inode)
845 if (!dentry->d_sb->s_xattr ||
846 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
849 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
853 err = 0; /* Not an error if there aren't any xattrs */
857 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
858 err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos);
859 mutex_unlock(&dir->d_inode->i_mutex);
869 static int reiserfs_check_acl(struct inode *inode, int mask)
871 struct posix_acl *acl;
872 int error = -EAGAIN; /* do regular unix permission checks by default */
874 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
878 error = posix_acl_permission(inode, acl, mask);
879 posix_acl_release(acl);
880 } else if (PTR_ERR(acl) != -ENODATA)
881 error = PTR_ERR(acl);
887 static int create_privroot(struct dentry *dentry)
890 struct inode *inode = dentry->d_parent->d_inode;
891 WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
893 err = xattr_mkdir(inode, dentry, 0700);
894 if (err || !dentry->d_inode) {
895 reiserfs_warning(dentry->d_sb, "jdm-20006",
896 "xattrs/ACLs enabled and couldn't "
897 "find/create .reiserfs_priv. "
902 dentry->d_inode->i_flags |= S_PRIVATE;
903 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
904 "storage.\n", PRIVROOT_NAME);
910 int __init reiserfs_xattr_register_handlers(void) { return 0; }
911 void reiserfs_xattr_unregister_handlers(void) {}
912 static int create_privroot(struct dentry *dentry) { return 0; }
915 /* Actual operations that are exported to VFS-land */
916 struct xattr_handler *reiserfs_xattr_handlers[] = {
917 #ifdef CONFIG_REISERFS_FS_XATTR
918 &reiserfs_xattr_user_handler,
919 &reiserfs_xattr_trusted_handler,
921 #ifdef CONFIG_REISERFS_FS_SECURITY
922 &reiserfs_xattr_security_handler,
924 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
925 &reiserfs_posix_acl_access_handler,
926 &reiserfs_posix_acl_default_handler,
931 static int xattr_mount_check(struct super_block *s)
933 /* We need generation numbers to ensure that the oid mapping is correct
934 * v3.5 filesystems don't have them. */
935 if (old_format_only(s)) {
936 if (reiserfs_xattrs_optional(s)) {
937 /* Old format filesystem, but optional xattrs have
938 * been enabled. Error out. */
939 reiserfs_warning(s, "jdm-2005",
940 "xattrs/ACLs not supported "
941 "on pre-v3.6 format filesystems. "
950 int reiserfs_permission(struct inode *inode, int mask)
953 * We don't do permission checks on the internal objects.
954 * Permissions are determined by the "owning" object.
956 if (IS_PRIVATE(inode))
959 #ifdef CONFIG_REISERFS_FS_XATTR
961 * Stat data v1 doesn't support ACLs.
963 if (get_inode_sd_version(inode) != STAT_DATA_V1)
964 return generic_permission(inode, mask, reiserfs_check_acl);
966 return generic_permission(inode, mask, NULL);
969 /* This will catch lookups from the fs root to .reiserfs_priv */
971 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
973 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
974 if (container_of(q1, struct dentry, d_name) == priv_root)
976 if (q1->len == name->len &&
977 !memcmp(q1->name, name->name, name->len))
982 static const struct dentry_operations xattr_lookup_poison_ops = {
983 .d_compare = xattr_lookup_poison,
986 int reiserfs_lookup_privroot(struct super_block *s)
988 struct dentry *dentry;
991 /* If we don't have the privroot located yet - go find it */
992 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
993 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
994 strlen(PRIVROOT_NAME));
995 if (!IS_ERR(dentry)) {
996 REISERFS_SB(s)->priv_root = dentry;
997 if (!reiserfs_expose_privroot(s))
998 s->s_root->d_op = &xattr_lookup_poison_ops;
1000 dentry->d_inode->i_flags |= S_PRIVATE;
1002 err = PTR_ERR(dentry);
1003 mutex_unlock(&s->s_root->d_inode->i_mutex);
1008 /* We need to take a copy of the mount flags since things like
1009 * MS_RDONLY don't get set until *after* we're called.
1010 * mount_flags != mount_options */
1011 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1014 struct dentry *privroot = REISERFS_SB(s)->priv_root;
1016 err = xattr_mount_check(s);
1020 if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
1021 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
1022 err = create_privroot(REISERFS_SB(s)->priv_root);
1023 mutex_unlock(&s->s_root->d_inode->i_mutex);
1026 if (privroot->d_inode) {
1027 s->s_xattr = reiserfs_xattr_handlers;
1028 reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
1029 if (!REISERFS_SB(s)->xattr_root) {
1030 struct dentry *dentry;
1031 dentry = lookup_one_len(XAROOT_NAME, privroot,
1032 strlen(XAROOT_NAME));
1033 if (!IS_ERR(dentry))
1034 REISERFS_SB(s)->xattr_root = dentry;
1036 err = PTR_ERR(dentry);
1038 mutex_unlock(&privroot->d_inode->i_mutex);
1043 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1044 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1047 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1048 if (reiserfs_posixacl(s))
1049 s->s_flags |= MS_POSIXACL;
1051 s->s_flags &= ~MS_POSIXACL;