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/smp_lock.h>
50 #include <linux/stat.h>
51 #include <linux/quotaops.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 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);
67 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode)
69 BUG_ON(!mutex_is_locked(&dir->i_mutex));
71 return dir->i_op->mkdir(dir, dentry, mode);
74 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
75 * mutation ops aren't called during rename or splace, which are the
76 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
77 * better than allocating another subclass just for this code. */
78 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
81 BUG_ON(!mutex_is_locked(&dir->i_mutex));
84 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
85 error = dir->i_op->unlink(dir, dentry);
86 mutex_unlock(&dentry->d_inode->i_mutex);
93 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
96 BUG_ON(!mutex_is_locked(&dir->i_mutex));
99 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
100 dentry_unhash(dentry);
101 error = dir->i_op->rmdir(dir, dentry);
103 dentry->d_inode->i_flags |= S_DEAD;
104 mutex_unlock(&dentry->d_inode->i_mutex);
112 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
114 /* Returns and possibly creates the xattr dir. */
115 static struct dentry *lookup_or_create_dir(struct dentry *parent,
116 const char *name, int flags)
118 struct dentry *dentry;
121 dentry = lookup_one_len(name, parent, strlen(name));
124 else if (!dentry->d_inode) {
127 if (xattr_may_create(flags)) {
128 mutex_lock_nested(&parent->d_inode->i_mutex,
130 err = xattr_mkdir(parent->d_inode, dentry, 0700);
131 mutex_unlock(&parent->d_inode->i_mutex);
136 dentry = ERR_PTR(err);
143 static struct dentry *open_xa_root(struct super_block *sb, int flags)
145 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
147 return ERR_PTR(-ENODATA);
148 return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
151 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
153 struct dentry *xaroot, *xadir;
156 xaroot = open_xa_root(inode->i_sb, flags);
160 snprintf(namebuf, sizeof(namebuf), "%X.%X",
161 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
162 inode->i_generation);
164 xadir = lookup_or_create_dir(xaroot, namebuf, flags);
171 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
172 * we need to drop the path before calling the filldir struct. That
173 * would be a big performance hit to the non-xattr case, so I've copied
174 * the whole thing for now. --clm
176 * the big difference is that I go backwards through the directory,
177 * and don't mess with f->f_pos, but the idea is the same. Do some
178 * action on each and every entry in the directory.
180 * we're called with i_mutex held, so there are no worries about the directory
181 * changing underneath us.
183 static int __xattr_readdir(struct inode *inode, void *dirent, filldir_t filldir)
185 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
186 INITIALIZE_PATH(path_to_entry);
187 struct buffer_head *bh;
189 struct item_head *ih, tmp_ih;
193 char small_buf[32]; /* avoid kmalloc if we can */
194 struct reiserfs_de_head *deh;
199 struct reiserfs_dir_entry de;
201 /* form key for search the next directory entry using f_pos field of
203 next_pos = max_reiserfs_offset(inode);
207 if (next_pos <= DOT_DOT_OFFSET)
209 make_cpu_key(&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
212 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
214 if (search_res == IO_ERROR) {
215 // FIXME: we could just skip part of directory which could
217 pathrelse(&path_to_entry);
221 if (search_res == NAME_NOT_FOUND)
224 set_de_name_and_namelen(&de);
225 entry_num = de.de_entry_num;
226 deh = &(de.de_deh[entry_num]);
231 if (!is_direntry_le_ih(ih)) {
232 reiserfs_error(inode->i_sb, "jdm-20000",
233 "not direntry %h", ih);
236 copy_item_head(&tmp_ih, ih);
238 /* we must have found item, that is item of this directory, */
239 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
240 "vs-9000: found item %h does not match to dir we readdir %K",
243 if (deh_offset(deh) <= DOT_DOT_OFFSET) {
247 /* look for the previous entry in the directory */
248 next_pos = deh_offset(deh) - 1;
250 if (!de_visible(deh))
251 /* it is hidden entry */
254 d_reclen = entry_length(bh, ih, entry_num);
255 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
256 d_off = deh_offset(deh);
257 d_ino = deh_objectid(deh);
259 if (!d_name[d_reclen - 1])
260 d_reclen = strlen(d_name);
262 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)) {
263 /* too big to send back to VFS */
267 /* Ignore the .reiserfs_priv entry */
268 if (reiserfs_xattrs(inode->i_sb) &&
269 !old_format_only(inode->i_sb) &&
271 le32_to_cpu(INODE_PKEY
272 (REISERFS_SB(inode->i_sb)->priv_root->d_inode)->
276 if (d_reclen <= 32) {
277 local_buf = small_buf;
279 local_buf = kmalloc(d_reclen, GFP_NOFS);
281 pathrelse(&path_to_entry);
284 if (item_moved(&tmp_ih, &path_to_entry)) {
287 /* sigh, must retry. Do this same offset again */
293 // Note, that we copy name to user space via temporary
294 // buffer (local_buf) because filldir will block if
295 // user space buffer is swapped out. At that time
296 // entry can move to somewhere else
297 memcpy(local_buf, d_name, d_reclen);
299 /* the filldir function might need to start transactions,
300 * or do who knows what. Release the path now that we've
301 * copied all the important stuff out of the deh
303 pathrelse(&path_to_entry);
305 if (filldir(dirent, local_buf, d_reclen, d_off, d_ino,
307 if (local_buf != small_buf) {
312 if (local_buf != small_buf) {
318 pathrelse(&path_to_entry);
323 * this could be done with dedicated readdir ops for the xattr files,
324 * but I want to get something working asap
325 * this is stolen from vfs_readdir
329 int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
332 if (!IS_DEADDIR(inode)) {
334 res = __xattr_readdir(inode, buf, filler);
340 /* The following are side effects of other operations that aren't explicitly
341 * modifying extended attributes. This includes operations such as permissions
342 * or ownership changes, object deletions, etc. */
345 reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
346 loff_t offset, u64 ino, unsigned int d_type)
348 struct dentry *xadir = (struct dentry *)buf;
349 struct dentry *dentry;
352 dentry = lookup_one_len(name, xadir, namelen);
353 if (IS_ERR(dentry)) {
354 err = PTR_ERR(dentry);
356 } else if (!dentry->d_inode) {
361 /* Skip directories.. */
362 if (S_ISDIR(dentry->d_inode->i_mode))
365 err = xattr_unlink(xadir->d_inode, dentry);
374 /* This is called w/ inode->i_mutex downed */
375 int reiserfs_delete_xattrs(struct inode *inode)
378 struct dentry *dir, *root;
379 struct reiserfs_transaction_handle th;
380 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
381 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
383 /* Skip out, an xattr has no xattrs associated with it */
384 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
387 dir = open_xa_dir(inode, XATTR_REPLACE);
391 } else if (!dir->d_inode) {
396 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
397 err = xattr_readdir(dir->d_inode, reiserfs_delete_xattrs_filler, dir);
398 mutex_unlock(&dir->d_inode->i_mutex);
404 root = dget(dir->d_parent);
407 /* We start a transaction here to avoid a ABBA situation
408 * between the xattr root's i_mutex and the journal lock.
409 * Inode creation will inherit an ACL, which requires a
410 * lookup. The lookup locks the xattr root i_mutex with a
411 * transaction open. Inode deletion takes teh xattr root
412 * i_mutex to delete the directory and then starts a
413 * transaction inside it. Boom. This doesn't incur much
414 * additional overhead since the reiserfs_rmdir transaction
415 * will just nest inside the outer transaction. */
416 err = journal_begin(&th, inode->i_sb, blocks);
419 mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_XATTR);
420 err = xattr_rmdir(root->d_inode, dir);
421 jerror = journal_end(&th, inode->i_sb, blocks);
422 mutex_unlock(&root->d_inode->i_mutex);
429 reiserfs_warning(inode->i_sb, "jdm-20004",
430 "Couldn't remove all xattrs (%d)\n", err);
434 struct reiserfs_chown_buf {
436 struct dentry *xadir;
440 /* XXX: If there is a better way to do this, I'd love to hear about it */
442 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
443 loff_t offset, u64 ino, unsigned int d_type)
445 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
446 struct dentry *xafile, *xadir = chown_buf->xadir;
447 struct iattr *attrs = chown_buf->attrs;
450 xafile = lookup_one_len(name, xadir, namelen);
452 return PTR_ERR(xafile);
453 else if (!xafile->d_inode) {
458 if (!S_ISDIR(xafile->d_inode->i_mode)) {
459 mutex_lock_nested(&xafile->d_inode->i_mutex, I_MUTEX_CHILD);
460 err = reiserfs_setattr(xafile, attrs);
461 mutex_unlock(&xafile->d_inode->i_mutex);
468 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
472 struct reiserfs_chown_buf buf;
473 unsigned int ia_valid = attrs->ia_valid;
475 /* Skip out, an xattr has no xattrs associated with it */
476 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
479 dir = open_xa_dir(inode, XATTR_REPLACE);
481 if (PTR_ERR(dir) != -ENODATA)
484 } else if (!dir->d_inode)
487 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
492 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
493 err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
496 err = reiserfs_setattr(dir, attrs);
497 mutex_unlock(&dir->d_inode->i_mutex);
499 attrs->ia_valid = ia_valid;
504 reiserfs_warning(inode->i_sb, "jdm-20007",
505 "Couldn't chown all xattrs (%d)\n", err);
509 #ifdef CONFIG_REISERFS_FS_XATTR
510 /* Returns a dentry corresponding to a specific extended attribute file
511 * for the inode. If flags allow, the file is created. Otherwise, a
512 * valid or negative dentry, or an error is returned. */
513 static struct dentry *xattr_lookup(struct inode *inode, const char *name,
516 struct dentry *xadir, *xafile;
519 xadir = open_xa_dir(inode, flags);
521 return ERR_CAST(xadir);
523 xafile = lookup_one_len(name, xadir, strlen(name));
524 if (IS_ERR(xafile)) {
525 err = PTR_ERR(xafile);
529 if (xafile->d_inode && (flags & XATTR_CREATE))
532 if (!xafile->d_inode) {
534 if (xattr_may_create(flags)) {
535 mutex_lock_nested(&xadir->d_inode->i_mutex,
537 err = xattr_create(xadir->d_inode, xafile,
539 mutex_unlock(&xadir->d_inode->i_mutex);
552 /* Internal operations on file data */
553 static inline void reiserfs_put_page(struct page *page)
556 page_cache_release(page);
559 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
561 struct address_space *mapping = dir->i_mapping;
563 /* We can deadlock if we try to free dentries,
564 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
565 mapping_set_gfp_mask(mapping, GFP_NOFS);
566 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
575 reiserfs_put_page(page);
576 return ERR_PTR(-EIO);
579 static inline __u32 xattr_hash(const char *msg, int len)
581 return csum_partial(msg, len, 0);
584 int reiserfs_commit_write(struct file *f, struct page *page,
585 unsigned from, unsigned to);
586 int reiserfs_prepare_write(struct file *f, struct page *page,
587 unsigned from, unsigned to);
589 static void update_ctime(struct inode *inode)
591 struct timespec now = current_fs_time(inode->i_sb);
592 if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
593 timespec_equal(&inode->i_ctime, &now))
596 inode->i_ctime = CURRENT_TIME_SEC;
597 mark_inode_dirty(inode);
600 static int lookup_and_delete_xattr(struct inode *inode, const char *name)
603 struct dentry *dentry, *xadir;
605 xadir = open_xa_dir(inode, XATTR_REPLACE);
607 return PTR_ERR(xadir);
609 dentry = lookup_one_len(name, xadir, strlen(name));
610 if (IS_ERR(dentry)) {
611 err = PTR_ERR(dentry);
615 if (dentry->d_inode) {
616 mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
617 err = xattr_unlink(xadir->d_inode, dentry);
618 mutex_unlock(&xadir->d_inode->i_mutex);
629 /* Generic extended attribute operations that can be used by xa plugins */
632 * inode->i_mutex: down
635 __reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
636 size_t buffer_size, int flags)
639 struct dentry *dentry;
643 size_t buffer_pos = 0;
647 if (get_inode_sd_version(inode) == STAT_DATA_V1)
651 return lookup_and_delete_xattr(inode, name);
653 dentry = xattr_lookup(inode, name, flags);
655 return PTR_ERR(dentry);
657 down_write(&REISERFS_I(inode)->i_xattr_sem);
659 xahash = xattr_hash(buffer, buffer_size);
660 while (buffer_pos < buffer_size || buffer_pos == 0) {
663 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
664 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
665 chunk = PAGE_CACHE_SIZE;
667 chunk = buffer_size - buffer_pos;
669 page = reiserfs_get_page(dentry->d_inode, file_pos);
676 data = page_address(page);
679 struct reiserfs_xattr_header *rxh;
680 skip = file_pos = sizeof(struct reiserfs_xattr_header);
681 if (chunk + skip > PAGE_CACHE_SIZE)
682 chunk = PAGE_CACHE_SIZE - skip;
683 rxh = (struct reiserfs_xattr_header *)data;
684 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
685 rxh->h_hash = cpu_to_le32(xahash);
688 err = reiserfs_prepare_write(NULL, page, page_offset,
689 page_offset + chunk + skip);
692 memcpy(data + skip, buffer + buffer_pos, chunk);
693 err = reiserfs_commit_write(NULL, page, page_offset,
694 page_offset + chunk +
698 reiserfs_put_page(page);
702 if (err || buffer_size == 0 || !buffer)
706 new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
707 if (!err && new_size < i_size_read(dentry->d_inode)) {
708 struct iattr newattrs = {
709 .ia_ctime = current_fs_time(inode->i_sb),
710 .ia_size = buffer_size,
711 .ia_valid = ATTR_SIZE | ATTR_CTIME,
713 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
714 down_write(&dentry->d_inode->i_alloc_sem);
715 err = reiserfs_setattr(dentry, &newattrs);
716 up_write(&dentry->d_inode->i_alloc_sem);
717 mutex_unlock(&dentry->d_inode->i_mutex);
721 up_write(&REISERFS_I(inode)->i_xattr_sem);
727 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
728 size_t buffer_size, int flags)
730 int err = __reiserfs_xattr_set(inode, name, buffer, buffer_size, flags);
737 * inode->i_mutex: down
740 reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
744 struct dentry *dentry;
747 size_t buffer_pos = 0;
754 /* We can't have xattrs attached to v1 items since they don't have
755 * generation numbers */
756 if (get_inode_sd_version(inode) == STAT_DATA_V1)
759 dentry = xattr_lookup(inode, name, XATTR_REPLACE);
760 if (IS_ERR(dentry)) {
761 err = PTR_ERR(dentry);
765 down_read(&REISERFS_I(inode)->i_xattr_sem);
767 isize = i_size_read(dentry->d_inode);
769 /* Just return the size needed */
770 if (buffer == NULL) {
771 err = isize - sizeof(struct reiserfs_xattr_header);
775 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
780 while (file_pos < isize) {
784 if (isize - file_pos > PAGE_CACHE_SIZE)
785 chunk = PAGE_CACHE_SIZE;
787 chunk = isize - file_pos;
789 page = reiserfs_get_page(dentry->d_inode, file_pos);
796 data = page_address(page);
798 struct reiserfs_xattr_header *rxh =
799 (struct reiserfs_xattr_header *)data;
800 skip = file_pos = sizeof(struct reiserfs_xattr_header);
802 /* Magic doesn't match up.. */
803 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
805 reiserfs_put_page(page);
806 reiserfs_warning(inode->i_sb, "jdm-20001",
807 "Invalid magic for xattr (%s) "
808 "associated with %k", name,
813 hash = le32_to_cpu(rxh->h_hash);
815 memcpy(buffer + buffer_pos, data + skip, chunk);
817 reiserfs_put_page(page);
822 err = isize - sizeof(struct reiserfs_xattr_header);
824 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
826 reiserfs_warning(inode->i_sb, "jdm-20002",
827 "Invalid hash for xattr (%s) associated "
828 "with %k", name, INODE_PKEY(inode));
833 up_read(&REISERFS_I(inode)->i_xattr_sem);
840 /* Actual operations that are exported to VFS-land */
841 struct xattr_handler *reiserfs_xattr_handlers[] = {
842 &reiserfs_xattr_user_handler,
843 &reiserfs_xattr_trusted_handler,
844 #ifdef CONFIG_REISERFS_FS_SECURITY
845 &reiserfs_xattr_security_handler,
847 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
848 &reiserfs_posix_acl_access_handler,
849 &reiserfs_posix_acl_default_handler,
855 * In order to implement different sets of xattr operations for each xattr
856 * prefix with the generic xattr API, a filesystem should create a
857 * null-terminated array of struct xattr_handler (one for each prefix) and
858 * hang a pointer to it off of the s_xattr field of the superblock.
860 * The generic_fooxattr() functions will use this list to dispatch xattr
861 * operations to the correct xattr_handler.
863 #define for_each_xattr_handler(handlers, handler) \
864 for ((handler) = *(handlers)++; \
866 (handler) = *(handlers)++)
868 /* This is the implementation for the xattr plugin infrastructure */
869 static inline struct xattr_handler *
870 find_xattr_handler_prefix(struct xattr_handler **handlers,
873 struct xattr_handler *xah;
878 for_each_xattr_handler(handlers, xah) {
879 if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
888 * Inode operation getxattr()
891 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
894 struct inode *inode = dentry->d_inode;
895 struct xattr_handler *handler;
897 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
899 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
902 return handler->get(inode, name, buffer, size);
906 * Inode operation setxattr()
908 * dentry->d_inode->i_mutex down
911 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
912 size_t size, int flags)
914 struct inode *inode = dentry->d_inode;
915 struct xattr_handler *handler;
917 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
919 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
922 return handler->set(inode, name, value, size, flags);
926 * Inode operation removexattr()
928 * dentry->d_inode->i_mutex down
930 int reiserfs_removexattr(struct dentry *dentry, const char *name)
932 struct inode *inode = dentry->d_inode;
933 struct xattr_handler *handler;
934 handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
936 if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
939 return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
942 struct listxattr_buf {
949 static int listxattr_filler(void *buf, const char *name, int namelen,
950 loff_t offset, u64 ino, unsigned int d_type)
952 struct listxattr_buf *b = (struct listxattr_buf *)buf;
954 if (name[0] != '.' ||
955 (namelen != 1 && (name[1] != '.' || namelen != 2))) {
956 struct xattr_handler *handler;
957 handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
959 if (!handler) /* Unsupported xattr name */
962 size = handler->list(b->inode, b->buf + b->pos,
963 b->size, name, namelen);
967 size = handler->list(b->inode, NULL, 0, name, namelen);
976 * Inode operation listxattr()
978 * We totally ignore the generic listxattr here because it would be stupid
979 * not to. Since the xattrs are organized in a directory, we can just
980 * readdir to find them.
982 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
986 struct listxattr_buf buf = {
987 .inode = dentry->d_inode,
989 .size = buffer ? size : 0,
992 if (!dentry->d_inode)
995 if (!reiserfs_xattrs(dentry->d_sb) ||
996 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
999 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
1002 if (err == -ENODATA)
1003 err = 0; /* Not an error if there aren't any xattrs */
1007 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
1008 err = xattr_readdir(dir->d_inode, listxattr_filler, &buf);
1009 mutex_unlock(&dir->d_inode->i_mutex);
1019 static int reiserfs_check_acl(struct inode *inode, int mask)
1021 struct posix_acl *acl;
1022 int error = -EAGAIN; /* do regular unix permission checks by default */
1024 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1028 error = posix_acl_permission(inode, acl, mask);
1029 posix_acl_release(acl);
1030 } else if (PTR_ERR(acl) != -ENODATA)
1031 error = PTR_ERR(acl);
1037 int reiserfs_permission(struct inode *inode, int mask)
1040 * We don't do permission checks on the internal objects.
1041 * Permissions are determined by the "owning" object.
1043 if (IS_PRIVATE(inode))
1046 * Stat data v1 doesn't support ACLs.
1048 if (get_inode_sd_version(inode) == STAT_DATA_V1)
1049 return generic_permission(inode, mask, NULL);
1051 return generic_permission(inode, mask, reiserfs_check_acl);
1054 static int create_privroot(struct dentry *dentry)
1057 struct inode *inode = dentry->d_parent->d_inode;
1058 mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
1059 err = xattr_mkdir(inode, dentry, 0700);
1060 mutex_unlock(&inode->i_mutex);
1066 if (dentry && dentry->d_inode)
1067 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
1068 "storage.\n", PRIVROOT_NAME);
1073 static int xattr_mount_check(struct super_block *s)
1075 /* We need generation numbers to ensure that the oid mapping is correct
1076 * v3.5 filesystems don't have them. */
1077 if (old_format_only(s)) {
1078 if (reiserfs_xattrs_optional(s)) {
1079 /* Old format filesystem, but optional xattrs have
1080 * been enabled. Error out. */
1081 reiserfs_warning(s, "jdm-2005",
1082 "xattrs/ACLs not supported "
1083 "on pre-v3.6 format filesystems. "
1093 int __init reiserfs_xattr_register_handlers(void) { return 0; }
1094 void reiserfs_xattr_unregister_handlers(void) {}
1097 /* This will catch lookups from the fs root to .reiserfs_priv */
1099 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1101 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1102 if (name->len == priv_root->d_name.len &&
1103 name->hash == priv_root->d_name.hash &&
1104 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1106 } else if (q1->len == name->len &&
1107 !memcmp(q1->name, name->name, name->len))
1112 static struct dentry_operations xattr_lookup_poison_ops = {
1113 .d_compare = xattr_lookup_poison,
1116 /* We need to take a copy of the mount flags since things like
1117 * MS_RDONLY don't get set until *after* we're called.
1118 * mount_flags != mount_options */
1119 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1123 #ifdef CONFIG_REISERFS_FS_XATTR
1124 err = xattr_mount_check(s);
1129 /* If we don't have the privroot located yet - go find it */
1130 if (!REISERFS_SB(s)->priv_root) {
1131 struct dentry *dentry;
1132 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1133 strlen(PRIVROOT_NAME));
1134 if (!IS_ERR(dentry)) {
1135 #ifdef CONFIG_REISERFS_FS_XATTR
1136 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode)
1137 err = create_privroot(dentry);
1139 if (!dentry->d_inode) {
1144 err = PTR_ERR(dentry);
1146 if (!err && dentry) {
1147 s->s_root->d_op = &xattr_lookup_poison_ops;
1148 dentry->d_inode->i_flags |= S_PRIVATE;
1149 REISERFS_SB(s)->priv_root = dentry;
1150 #ifdef CONFIG_REISERFS_FS_XATTR
1151 /* xattrs are unavailable */
1152 } else if (!(mount_flags & MS_RDONLY)) {
1153 /* If we're read-only it just means that the dir
1154 * hasn't been created. Not an error -- just no
1155 * xattrs on the fs. We'll check again if we
1157 reiserfs_warning(s, "jdm-20006",
1158 "xattrs/ACLs enabled and couldn't "
1159 "find/create .reiserfs_priv. "
1166 #ifdef CONFIG_REISERFS_FS_XATTR
1168 s->s_xattr = reiserfs_xattr_handlers;
1172 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1173 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1177 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1178 s->s_flags = s->s_flags & ~MS_POSIXACL;
1179 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1180 if (reiserfs_posixacl(s))
1181 s->s_flags |= MS_POSIXACL;