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));
65 return dir->i_op->create(dir, dentry, mode, NULL);
69 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode)
71 BUG_ON(!mutex_is_locked(&dir->i_mutex));
73 return dir->i_op->mkdir(dir, dentry, mode);
76 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
77 * mutation ops aren't called during rename or splace, which are the
78 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
79 * better than allocating another subclass just for this code. */
80 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
83 BUG_ON(!mutex_is_locked(&dir->i_mutex));
86 reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
87 I_MUTEX_CHILD, dir->i_sb);
88 error = dir->i_op->unlink(dir, dentry);
89 mutex_unlock(&dentry->d_inode->i_mutex);
96 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
99 BUG_ON(!mutex_is_locked(&dir->i_mutex));
102 reiserfs_mutex_lock_nested_safe(&dentry->d_inode->i_mutex,
103 I_MUTEX_CHILD, dir->i_sb);
104 dentry_unhash(dentry);
105 error = dir->i_op->rmdir(dir, dentry);
107 dentry->d_inode->i_flags |= S_DEAD;
108 mutex_unlock(&dentry->d_inode->i_mutex);
116 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
118 static struct dentry *open_xa_root(struct super_block *sb, int flags)
120 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
121 struct dentry *xaroot;
122 if (!privroot->d_inode)
123 return ERR_PTR(-ENODATA);
125 mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
127 xaroot = dget(REISERFS_SB(sb)->xattr_root);
129 xaroot = ERR_PTR(-ENODATA);
130 else if (!xaroot->d_inode) {
132 if (xattr_may_create(flags))
133 err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
136 xaroot = ERR_PTR(err);
140 mutex_unlock(&privroot->d_inode->i_mutex);
144 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
146 struct dentry *xaroot, *xadir;
149 xaroot = open_xa_root(inode->i_sb, flags);
153 snprintf(namebuf, sizeof(namebuf), "%X.%X",
154 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
155 inode->i_generation);
157 mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
159 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
160 if (!IS_ERR(xadir) && !xadir->d_inode) {
162 if (xattr_may_create(flags))
163 err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
166 xadir = ERR_PTR(err);
170 mutex_unlock(&xaroot->d_inode->i_mutex);
175 /* The following are side effects of other operations that aren't explicitly
176 * modifying extended attributes. This includes operations such as permissions
177 * or ownership changes, object deletions, etc. */
178 struct reiserfs_dentry_buf {
179 struct dentry *xadir;
181 struct dentry *dentries[8];
185 fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
186 u64 ino, unsigned int d_type)
188 struct reiserfs_dentry_buf *dbuf = buf;
189 struct dentry *dentry;
190 WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
192 if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
195 if (name[0] == '.' && (name[1] == '\0' ||
196 (name[1] == '.' && name[2] == '\0')))
199 dentry = lookup_one_len(name, dbuf->xadir, namelen);
200 if (IS_ERR(dentry)) {
201 return PTR_ERR(dentry);
202 } else if (!dentry->d_inode) {
203 /* A directory entry exists, but no file? */
204 reiserfs_error(dentry->d_sb, "xattr-20003",
205 "Corrupted directory: xattr %s listed but "
206 "not found for file %s.\n",
207 dentry->d_name.name, dbuf->xadir->d_name.name);
212 dbuf->dentries[dbuf->count++] = dentry;
217 cleanup_dentry_buf(struct reiserfs_dentry_buf *buf)
220 for (i = 0; i < buf->count; i++)
221 if (buf->dentries[i])
222 dput(buf->dentries[i]);
225 static int reiserfs_for_each_xattr(struct inode *inode,
226 int (*action)(struct dentry *, void *),
232 struct reiserfs_dentry_buf buf = {
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 reiserfs_write_unlock(inode->i_sb);
241 dir = open_xa_dir(inode, XATTR_REPLACE);
244 reiserfs_write_lock(inode->i_sb);
246 } else if (!dir->d_inode) {
248 reiserfs_write_lock(inode->i_sb);
252 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
254 reiserfs_write_lock(inode->i_sb);
257 err = reiserfs_readdir_dentry(dir, &buf, fill_with_dentries, &pos);
258 while ((err == 0 || err == -ENOSPC) && buf.count) {
261 for (i = 0; i < buf.count && buf.dentries[i]; i++) {
263 struct dentry *dentry = buf.dentries[i];
265 if (err == 0 && !S_ISDIR(dentry->d_inode->i_mode))
266 lerr = action(dentry, data);
269 buf.dentries[i] = NULL;
274 err = reiserfs_readdir_dentry(dir, &buf,
275 fill_with_dentries, &pos);
277 mutex_unlock(&dir->d_inode->i_mutex);
279 /* Clean up after a failed readdir */
280 cleanup_dentry_buf(&buf);
283 /* We start a transaction here to avoid a ABBA situation
284 * between the xattr root's i_mutex and the journal lock.
285 * This doesn't incur much additional overhead since the
286 * new transaction will just nest inside the
287 * outer transaction. */
288 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
289 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
290 struct reiserfs_transaction_handle th;
291 err = journal_begin(&th, inode->i_sb, blocks);
294 reiserfs_mutex_lock_nested_safe(
295 &dir->d_parent->d_inode->i_mutex,
296 I_MUTEX_XATTR, inode->i_sb);
297 err = action(dir, data);
298 jerror = journal_end(&th, inode->i_sb, blocks);
299 mutex_unlock(&dir->d_parent->d_inode->i_mutex);
306 /* -ENODATA isn't an error */
312 static int delete_one_xattr(struct dentry *dentry, void *data)
314 struct inode *dir = dentry->d_parent->d_inode;
316 /* This is the xattr dir, handle specially. */
317 if (S_ISDIR(dentry->d_inode->i_mode))
318 return xattr_rmdir(dir, dentry);
320 return xattr_unlink(dir, dentry);
323 static int chown_one_xattr(struct dentry *dentry, void *data)
325 struct iattr *attrs = data;
326 return reiserfs_setattr(dentry, attrs);
329 /* No i_mutex, but the inode is unconnected. */
330 int reiserfs_delete_xattrs(struct inode *inode)
332 int err = reiserfs_for_each_xattr(inode, delete_one_xattr, NULL);
334 reiserfs_warning(inode->i_sb, "jdm-20004",
335 "Couldn't delete all xattrs (%d)\n", err);
339 /* inode->i_mutex: down */
340 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
342 int err = reiserfs_for_each_xattr(inode, chown_one_xattr, attrs);
344 reiserfs_warning(inode->i_sb, "jdm-20007",
345 "Couldn't chown all xattrs (%d)\n", err);
349 #ifdef CONFIG_REISERFS_FS_XATTR
350 /* Returns a dentry corresponding to a specific extended attribute file
351 * for the inode. If flags allow, the file is created. Otherwise, a
352 * valid or negative dentry, or an error is returned. */
353 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
356 struct dentry *xadir, *xafile;
359 xadir = open_xa_dir(inode, flags);
361 return ERR_CAST(xadir);
363 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
364 xafile = lookup_one_len(name, xadir, strlen(name));
365 if (IS_ERR(xafile)) {
366 err = PTR_ERR(xafile);
370 if (xafile->d_inode && (flags & XATTR_CREATE))
373 if (!xafile->d_inode) {
375 if (xattr_may_create(flags))
376 err = xattr_create(xadir->d_inode, xafile,
383 mutex_unlock(&xadir->d_inode->i_mutex);
390 /* Internal operations on file data */
391 static inline void reiserfs_put_page(struct page *page)
394 page_cache_release(page);
397 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
399 struct address_space *mapping = dir->i_mapping;
401 /* We can deadlock if we try to free dentries,
402 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
403 mapping_set_gfp_mask(mapping, GFP_NOFS);
404 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
413 reiserfs_put_page(page);
414 return ERR_PTR(-EIO);
417 static inline __u32 xattr_hash(const char *msg, int len)
419 return csum_partial(msg, len, 0);
422 int reiserfs_commit_write(struct file *f, struct page *page,
423 unsigned from, unsigned to);
424 int reiserfs_prepare_write(struct file *f, struct page *page,
425 unsigned from, unsigned to);
427 static void update_ctime(struct inode *inode)
429 struct timespec now = current_fs_time(inode->i_sb);
430 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
431 timespec_equal(&inode->i_ctime, &now))
434 inode->i_ctime = CURRENT_TIME_SEC;
435 mark_inode_dirty(inode);
438 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
441 struct dentry *dentry, *xadir;
443 xadir = open_xa_dir(inode, XATTR_REPLACE);
445 return PTR_ERR(xadir);
447 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
448 dentry = lookup_one_len(name, xadir, strlen(name));
449 if (IS_ERR(dentry)) {
450 err = PTR_ERR(dentry);
454 if (dentry->d_inode) {
455 reiserfs_write_lock(inode->i_sb);
456 err = xattr_unlink(xadir->d_inode, dentry);
457 reiserfs_write_unlock(inode->i_sb);
463 mutex_unlock(&xadir->d_inode->i_mutex);
469 /* Generic extended attribute operations that can be used by xa plugins */
472 * inode->i_mutex: down
475 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
476 struct inode *inode, const char *name,
477 const void *buffer, size_t buffer_size, int flags)
480 struct dentry *dentry;
484 size_t buffer_pos = 0;
488 if (get_inode_sd_version(inode) == STAT_DATA_V1)
491 reiserfs_write_unlock(inode->i_sb);
494 err = lookup_and_delete_xattr(inode, name);
495 reiserfs_write_lock(inode->i_sb);
499 dentry = xattr_lookup(inode, name, flags);
500 if (IS_ERR(dentry)) {
501 reiserfs_write_lock(inode->i_sb);
502 return PTR_ERR(dentry);
505 down_write(&REISERFS_I(inode)->i_xattr_sem);
507 reiserfs_write_lock(inode->i_sb);
509 xahash = xattr_hash(buffer, buffer_size);
510 while (buffer_pos < buffer_size || buffer_pos == 0) {
513 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
514 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
515 chunk = PAGE_CACHE_SIZE;
517 chunk = buffer_size - buffer_pos;
519 page = reiserfs_get_page(dentry->d_inode, file_pos);
526 data = page_address(page);
529 struct reiserfs_xattr_header *rxh;
530 skip = file_pos = sizeof(struct reiserfs_xattr_header);
531 if (chunk + skip > PAGE_CACHE_SIZE)
532 chunk = PAGE_CACHE_SIZE - skip;
533 rxh = (struct reiserfs_xattr_header *)data;
534 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
535 rxh->h_hash = cpu_to_le32(xahash);
538 err = reiserfs_prepare_write(NULL, page, page_offset,
539 page_offset + chunk + skip);
542 memcpy(data + skip, buffer + buffer_pos, chunk);
543 err = reiserfs_commit_write(NULL, page, page_offset,
544 page_offset + chunk +
548 reiserfs_put_page(page);
552 if (err || buffer_size == 0 || !buffer)
556 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
557 if (!err && new_size < i_size_read(dentry->d_inode)) {
558 struct iattr newattrs = {
559 .ia_ctime = current_fs_time(inode->i_sb),
560 .ia_size = buffer_size,
561 .ia_valid = ATTR_SIZE | ATTR_CTIME,
564 reiserfs_write_unlock(inode->i_sb);
565 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
566 down_write(&dentry->d_inode->i_alloc_sem);
567 reiserfs_write_lock(inode->i_sb);
569 err = reiserfs_setattr(dentry, &newattrs);
570 up_write(&dentry->d_inode->i_alloc_sem);
571 mutex_unlock(&dentry->d_inode->i_mutex);
575 up_write(&REISERFS_I(inode)->i_xattr_sem);
580 /* We need to start a transaction to maintain lock ordering */
581 int reiserfs_xattr_set(struct inode *inode, const char *name,
582 const void *buffer, size_t buffer_size, int flags)
585 struct reiserfs_transaction_handle th;
587 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
589 if (!(flags & XATTR_REPLACE))
590 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
592 reiserfs_write_lock(inode->i_sb);
593 error = journal_begin(&th, inode->i_sb, jbegin_count);
595 reiserfs_write_unlock(inode->i_sb);
599 error = reiserfs_xattr_set_handle(&th, inode, name,
600 buffer, buffer_size, flags);
602 error2 = journal_end(&th, inode->i_sb, jbegin_count);
605 reiserfs_write_unlock(inode->i_sb);
611 * inode->i_mutex: down
614 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
618 struct dentry *dentry;
621 size_t buffer_pos = 0;
628 /* We can't have xattrs attached to v1 items since they don't have
629 * generation numbers */
630 if (get_inode_sd_version(inode) == STAT_DATA_V1)
633 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
634 if (IS_ERR(dentry)) {
635 err = PTR_ERR(dentry);
639 down_read(&REISERFS_I(inode)->i_xattr_sem);
641 isize = i_size_read(dentry->d_inode);
643 /* Just return the size needed */
644 if (buffer == NULL) {
645 err = isize - sizeof(struct reiserfs_xattr_header);
649 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
654 while (file_pos < isize) {
658 if (isize - file_pos > PAGE_CACHE_SIZE)
659 chunk = PAGE_CACHE_SIZE;
661 chunk = isize - file_pos;
663 page = reiserfs_get_page(dentry->d_inode, file_pos);
670 data = page_address(page);
672 struct reiserfs_xattr_header *rxh =
673 (struct reiserfs_xattr_header *)data;
674 skip = file_pos = sizeof(struct reiserfs_xattr_header);
676 /* Magic doesn't match up.. */
677 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
679 reiserfs_put_page(page);
680 reiserfs_warning(inode->i_sb, "jdm-20001",
681 "Invalid magic for xattr (%s) "
682 "associated with %k", name,
687 hash = le32_to_cpu(rxh->h_hash);
689 memcpy(buffer + buffer_pos, data + skip, chunk);
691 reiserfs_put_page(page);
696 err = isize - sizeof(struct reiserfs_xattr_header);
698 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
700 reiserfs_warning(inode->i_sb, "jdm-20002",
701 "Invalid hash for xattr (%s) associated "
702 "with %k", name, INODE_PKEY(inode));
707 up_read(&REISERFS_I(inode)->i_xattr_sem);
715 * In order to implement different sets of xattr operations for each xattr
716 * prefix with the generic xattr API, a filesystem should create a
717 * null-terminated array of struct xattr_handler (one for each prefix) and
718 * hang a pointer to it off of the s_xattr field of the superblock.
720 * The generic_fooxattr() functions will use this list to dispatch xattr
721 * operations to the correct xattr_handler.
723 #define for_each_xattr_handler(handlers, handler) \
724 for ((handler) = *(handlers)++; \
726 (handler) = *(handlers)++)
728 /* This is the implementation for the xattr plugin infrastructure */
729 static inline struct xattr_handler *
730 find_xattr_handler_prefix(struct xattr_handler **handlers,
733 struct xattr_handler *xah;
738 for_each_xattr_handler(handlers, xah) {
739 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
748 * Inode operation getxattr()
751 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
754 struct xattr_handler *handler;
756 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
758 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
761 return handler->get(dentry, name, buffer, size, handler->flags);
765 * Inode operation setxattr()
767 * dentry->d_inode->i_mutex down
770 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
771 size_t size, int flags)
773 struct xattr_handler *handler;
775 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
777 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
780 return handler->set(dentry, name, value, size, flags, handler->flags);
784 * Inode operation removexattr()
786 * dentry->d_inode->i_mutex down
788 int reiserfs_removexattr(struct dentry *dentry, const char *name)
790 struct xattr_handler *handler;
791 handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
793 if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
796 return handler->set(dentry, name, NULL, 0, XATTR_REPLACE, handler->flags);
799 struct listxattr_buf {
803 struct dentry *dentry;
806 static int listxattr_filler(void *buf, const char *name, int namelen,
807 loff_t offset, u64 ino, unsigned int d_type)
809 struct listxattr_buf *b = (struct listxattr_buf *)buf;
811 if (name[0] != '.' ||
812 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
813 struct xattr_handler *handler;
814 handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr,
816 if (!handler) /* Unsupported xattr name */
819 size = handler->list(b->dentry, b->buf + b->pos,
820 b->size, name, namelen,
825 size = handler->list(b->dentry, NULL, 0, name,
826 namelen, handler->flags);
835 * Inode operation listxattr()
837 * We totally ignore the generic listxattr here because it would be stupid
838 * not to. Since the xattrs are organized in a directory, we can just
839 * readdir to find them.
841 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
846 struct listxattr_buf buf = {
849 .size = buffer ? size : 0,
852 if (!dentry->d_inode)
855 if (!dentry->d_sb->s_xattr ||
856 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
859 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
863 err = 0; /* Not an error if there aren't any xattrs */
867 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
868 err = reiserfs_readdir_dentry(dir, &buf, listxattr_filler, &pos);
869 mutex_unlock(&dir->d_inode->i_mutex);
879 static int reiserfs_check_acl(struct inode *inode, int mask)
881 struct posix_acl *acl;
882 int error = -EAGAIN; /* do regular unix permission checks by default */
884 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
888 error = posix_acl_permission(inode, acl, mask);
889 posix_acl_release(acl);
890 } else if (PTR_ERR(acl) != -ENODATA)
891 error = PTR_ERR(acl);
897 static int create_privroot(struct dentry *dentry)
900 struct inode *inode = dentry->d_parent->d_inode;
901 WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
903 err = xattr_mkdir(inode, dentry, 0700);
904 if (err || !dentry->d_inode) {
905 reiserfs_warning(dentry->d_sb, "jdm-20006",
906 "xattrs/ACLs enabled and couldn't "
907 "find/create .reiserfs_priv. "
912 dentry->d_inode->i_flags |= S_PRIVATE;
913 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
914 "storage.\n", PRIVROOT_NAME);
920 int __init reiserfs_xattr_register_handlers(void) { return 0; }
921 void reiserfs_xattr_unregister_handlers(void) {}
922 static int create_privroot(struct dentry *dentry) { return 0; }
925 /* Actual operations that are exported to VFS-land */
926 struct xattr_handler *reiserfs_xattr_handlers[] = {
927 #ifdef CONFIG_REISERFS_FS_XATTR
928 &reiserfs_xattr_user_handler,
929 &reiserfs_xattr_trusted_handler,
931 #ifdef CONFIG_REISERFS_FS_SECURITY
932 &reiserfs_xattr_security_handler,
934 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
935 &reiserfs_posix_acl_access_handler,
936 &reiserfs_posix_acl_default_handler,
941 static int xattr_mount_check(struct super_block *s)
943 /* We need generation numbers to ensure that the oid mapping is correct
944 * v3.5 filesystems don't have them. */
945 if (old_format_only(s)) {
946 if (reiserfs_xattrs_optional(s)) {
947 /* Old format filesystem, but optional xattrs have
948 * been enabled. Error out. */
949 reiserfs_warning(s, "jdm-2005",
950 "xattrs/ACLs not supported "
951 "on pre-v3.6 format filesystems. "
960 int reiserfs_permission(struct inode *inode, int mask)
963 * We don't do permission checks on the internal objects.
964 * Permissions are determined by the "owning" object.
966 if (IS_PRIVATE(inode))
969 #ifdef CONFIG_REISERFS_FS_XATTR
971 * Stat data v1 doesn't support ACLs.
973 if (get_inode_sd_version(inode) != STAT_DATA_V1)
974 return generic_permission(inode, mask, reiserfs_check_acl);
976 return generic_permission(inode, mask, NULL);
979 /* This will catch lookups from the fs root to .reiserfs_priv */
981 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
983 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
984 if (container_of(q1, struct dentry, d_name) == priv_root)
986 if (q1->len == name->len &&
987 !memcmp(q1->name, name->name, name->len))
992 static const struct dentry_operations xattr_lookup_poison_ops = {
993 .d_compare = xattr_lookup_poison,
996 int reiserfs_lookup_privroot(struct super_block *s)
998 struct dentry *dentry;
1001 /* If we don't have the privroot located yet - go find it */
1002 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
1003 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1004 strlen(PRIVROOT_NAME));
1005 if (!IS_ERR(dentry)) {
1006 REISERFS_SB(s)->priv_root = dentry;
1007 if (!reiserfs_expose_privroot(s))
1008 s->s_root->d_op = &xattr_lookup_poison_ops;
1009 if (dentry->d_inode)
1010 dentry->d_inode->i_flags |= S_PRIVATE;
1012 err = PTR_ERR(dentry);
1013 mutex_unlock(&s->s_root->d_inode->i_mutex);
1018 /* We need to take a copy of the mount flags since things like
1019 * MS_RDONLY don't get set until *after* we're called.
1020 * mount_flags != mount_options */
1021 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1024 struct dentry *privroot = REISERFS_SB(s)->priv_root;
1026 err = xattr_mount_check(s);
1030 if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
1031 reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
1032 err = create_privroot(REISERFS_SB(s)->priv_root);
1033 mutex_unlock(&s->s_root->d_inode->i_mutex);
1036 if (privroot->d_inode) {
1037 s->s_xattr = reiserfs_xattr_handlers;
1038 reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
1039 if (!REISERFS_SB(s)->xattr_root) {
1040 struct dentry *dentry;
1041 dentry = lookup_one_len(XAROOT_NAME, privroot,
1042 strlen(XAROOT_NAME));
1043 if (!IS_ERR(dentry))
1044 REISERFS_SB(s)->xattr_root = dentry;
1046 err = PTR_ERR(dentry);
1048 mutex_unlock(&privroot->d_inode->i_mutex);
1053 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1054 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1057 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1058 if (reiserfs_posixacl(s))
1059 s->s_flags |= MS_POSIXACL;
1061 s->s_flags &= ~MS_POSIXACL;