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 reiserfs_write_lock(inode->i_sb);
455 err = xattr_unlink(xadir->d_inode, dentry);
456 reiserfs_write_unlock(inode->i_sb);
462 mutex_unlock(&xadir->d_inode->i_mutex);
468 /* Generic extended attribute operations that can be used by xa plugins */
471 * inode->i_mutex: down
474 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
475 struct inode *inode, const char *name,
476 const void *buffer, size_t buffer_size, int flags)
479 struct dentry *dentry;
483 size_t buffer_pos = 0;
487 if (get_inode_sd_version(inode) == STAT_DATA_V1)
490 reiserfs_write_unlock(inode->i_sb);
493 err = lookup_and_delete_xattr(inode, name);
494 reiserfs_write_lock(inode->i_sb);
498 dentry = xattr_lookup(inode, name, flags);
499 if (IS_ERR(dentry)) {
500 reiserfs_write_lock(inode->i_sb);
501 return PTR_ERR(dentry);
504 down_write(&REISERFS_I(inode)->i_xattr_sem);
506 reiserfs_write_lock(inode->i_sb);
508 xahash = xattr_hash(buffer, buffer_size);
509 while (buffer_pos < buffer_size || buffer_pos == 0) {
512 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
513 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
514 chunk = PAGE_CACHE_SIZE;
516 chunk = buffer_size - buffer_pos;
518 page = reiserfs_get_page(dentry->d_inode, file_pos);
525 data = page_address(page);
528 struct reiserfs_xattr_header *rxh;
529 skip = file_pos = sizeof(struct reiserfs_xattr_header);
530 if (chunk + skip > PAGE_CACHE_SIZE)
531 chunk = PAGE_CACHE_SIZE - skip;
532 rxh = (struct reiserfs_xattr_header *)data;
533 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
534 rxh->h_hash = cpu_to_le32(xahash);
537 err = reiserfs_prepare_write(NULL, page, page_offset,
538 page_offset + chunk + skip);
541 memcpy(data + skip, buffer + buffer_pos, chunk);
542 err = reiserfs_commit_write(NULL, page, page_offset,
543 page_offset + chunk +
547 reiserfs_put_page(page);
551 if (err || buffer_size == 0 || !buffer)
555 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
556 if (!err && new_size < i_size_read(dentry->d_inode)) {
557 struct iattr newattrs = {
558 .ia_ctime = current_fs_time(inode->i_sb),
559 .ia_size = buffer_size,
560 .ia_valid = ATTR_SIZE | ATTR_CTIME,
563 reiserfs_write_unlock(inode->i_sb);
564 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
565 down_write(&dentry->d_inode->i_alloc_sem);
566 reiserfs_write_lock(inode->i_sb);
568 err = reiserfs_setattr(dentry, &newattrs);
569 up_write(&dentry->d_inode->i_alloc_sem);
570 mutex_unlock(&dentry->d_inode->i_mutex);
574 up_write(&REISERFS_I(inode)->i_xattr_sem);
579 /* We need to start a transaction to maintain lock ordering */
580 int reiserfs_xattr_set(struct inode *inode, const char *name,
581 const void *buffer, size_t buffer_size, int flags)
584 struct reiserfs_transaction_handle th;
586 size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);
588 if (!(flags & XATTR_REPLACE))
589 jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);
591 reiserfs_write_lock(inode->i_sb);
592 error = journal_begin(&th, inode->i_sb, jbegin_count);
594 reiserfs_write_unlock(inode->i_sb);
598 error = reiserfs_xattr_set_handle(&th, inode, name,
599 buffer, buffer_size, flags);
601 error2 = journal_end(&th, inode->i_sb, jbegin_count);
604 reiserfs_write_unlock(inode->i_sb);
610 * inode->i_mutex: down
613 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
617 struct dentry *dentry;
620 size_t buffer_pos = 0;
627 /* We can't have xattrs attached to v1 items since they don't have
628 * generation numbers */
629 if (get_inode_sd_version(inode) == STAT_DATA_V1)
632 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
633 if (IS_ERR(dentry)) {
634 err = PTR_ERR(dentry);
638 down_read(&REISERFS_I(inode)->i_xattr_sem);
640 isize = i_size_read(dentry->d_inode);
642 /* Just return the size needed */
643 if (buffer == NULL) {
644 err = isize - sizeof(struct reiserfs_xattr_header);
648 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
653 while (file_pos < isize) {
657 if (isize - file_pos > PAGE_CACHE_SIZE)
658 chunk = PAGE_CACHE_SIZE;
660 chunk = isize - file_pos;
662 page = reiserfs_get_page(dentry->d_inode, file_pos);
669 data = page_address(page);
671 struct reiserfs_xattr_header *rxh =
672 (struct reiserfs_xattr_header *)data;
673 skip = file_pos = sizeof(struct reiserfs_xattr_header);
675 /* Magic doesn't match up.. */
676 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
678 reiserfs_put_page(page);
679 reiserfs_warning(inode->i_sb, "jdm-20001",
680 "Invalid magic for xattr (%s) "
681 "associated with %k", name,
686 hash = le32_to_cpu(rxh->h_hash);
688 memcpy(buffer + buffer_pos, data + skip, chunk);
690 reiserfs_put_page(page);
695 err = isize - sizeof(struct reiserfs_xattr_header);
697 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
699 reiserfs_warning(inode->i_sb, "jdm-20002",
700 "Invalid hash for xattr (%s) associated "
701 "with %k", name, INODE_PKEY(inode));
706 up_read(&REISERFS_I(inode)->i_xattr_sem);
714 * In order to implement different sets of xattr operations for each xattr
715 * prefix with the generic xattr API, a filesystem should create a
716 * null-terminated array of struct xattr_handler (one for each prefix) and
717 * hang a pointer to it off of the s_xattr field of the superblock.
719 * The generic_fooxattr() functions will use this list to dispatch xattr
720 * operations to the correct xattr_handler.
722 #define for_each_xattr_handler(handlers, handler) \
723 for ((handler) = *(handlers)++; \
725 (handler) = *(handlers)++)
727 /* This is the implementation for the xattr plugin infrastructure */
728 static inline struct xattr_handler *
729 find_xattr_handler_prefix(struct xattr_handler **handlers,
732 struct xattr_handler *xah;
737 for_each_xattr_handler(handlers, xah) {
738 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
747 * Inode operation getxattr()
750 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
753 struct inode *inode = dentry->d_inode;
754 struct xattr_handler *handler;
756 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
758 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
761 return handler->get(inode, name, buffer, size);
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 inode *inode = dentry->d_inode;
774 struct xattr_handler *handler;
776 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
778 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
781 return handler->set(inode, name, value, size, flags);
785 * Inode operation removexattr()
787 * dentry->d_inode->i_mutex down
789 int reiserfs_removexattr(struct dentry *dentry, const char *name)
791 struct inode *inode = dentry->d_inode;
792 struct xattr_handler *handler;
793 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
795 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
798 return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
801 struct listxattr_buf {
808 static int listxattr_filler(void *buf, const char *name, int namelen,
809 loff_t offset, u64 ino, unsigned int d_type)
811 struct listxattr_buf *b = (struct listxattr_buf *)buf;
813 if (name[0] != '.' ||
814 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
815 struct xattr_handler *handler;
816 handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
818 if (!handler) /* Unsupported xattr name */
821 size = handler->list(b->inode, b->buf + b->pos,
822 b->size, name, namelen);
826 size = handler->list(b->inode, NULL, 0, name, namelen);
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 = {
847 .inode = dentry->d_inode,
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;