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.
32 #include <linux/reiserfs_fs.h>
33 #include <linux/capability.h>
34 #include <linux/dcache.h>
35 #include <linux/namei.h>
36 #include <linux/errno.h>
38 #include <linux/file.h>
39 #include <linux/pagemap.h>
40 #include <linux/xattr.h>
41 #include <linux/reiserfs_xattr.h>
42 #include <linux/reiserfs_acl.h>
43 #include <asm/uaccess.h>
44 #include <net/checksum.h>
45 #include <linux/smp_lock.h>
46 #include <linux/stat.h>
47 #include <linux/quotaops.h>
49 #define PRIVROOT_NAME ".reiserfs_priv"
50 #define XAROOT_NAME "xattrs"
52 /* Helpers for inode ops. We do this so that we don't have all the VFS
53 * overhead and also for proper i_mutex annotation.
54 * dir->i_mutex must be held for all of them. */
55 static int xattr_create(struct inode *dir, struct dentry *dentry, int mode)
57 BUG_ON(!mutex_is_locked(&dir->i_mutex));
59 return dir->i_op->create(dir, dentry, mode, NULL);
62 static int xattr_mkdir(struct inode *dir, struct dentry *dentry, int mode)
64 BUG_ON(!mutex_is_locked(&dir->i_mutex));
66 return dir->i_op->mkdir(dir, dentry, mode);
69 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
70 * mutation ops aren't called during rename or splace, which are the
71 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
72 * better than allocating another subclass just for this code. */
73 static int xattr_unlink(struct inode *dir, struct dentry *dentry)
76 BUG_ON(!mutex_is_locked(&dir->i_mutex));
79 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
80 error = dir->i_op->unlink(dir, dentry);
81 mutex_unlock(&dentry->d_inode->i_mutex);
88 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
91 BUG_ON(!mutex_is_locked(&dir->i_mutex));
94 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
95 dentry_unhash(dentry);
96 error = dir->i_op->rmdir(dir, dentry);
98 dentry->d_inode->i_flags |= S_DEAD;
99 mutex_unlock(&dentry->d_inode->i_mutex);
108 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
110 /* Returns and possibly creates the xattr dir. */
111 static struct dentry *lookup_or_create_dir(struct dentry *parent,
112 const char *name, int flags)
114 struct dentry *dentry;
117 dentry = lookup_one_len(name, parent, strlen(name));
120 else if (!dentry->d_inode) {
123 if (xattr_may_create(flags)) {
124 mutex_lock_nested(&parent->d_inode->i_mutex,
126 err = xattr_mkdir(parent->d_inode, dentry, 0700);
127 mutex_unlock(&parent->d_inode->i_mutex);
132 dentry = ERR_PTR(err);
139 static struct dentry *open_xa_root(struct super_block *sb, int flags)
141 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
143 return ERR_PTR(-ENODATA);
144 return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
147 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
149 struct dentry *xaroot, *xadir;
152 xaroot = open_xa_root(inode->i_sb, flags);
156 snprintf(namebuf, sizeof(namebuf), "%X.%X",
157 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
158 inode->i_generation);
160 xadir = lookup_or_create_dir(xaroot, namebuf, flags);
167 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
168 * we need to drop the path before calling the filldir struct. That
169 * would be a big performance hit to the non-xattr case, so I've copied
170 * the whole thing for now. --clm
172 * the big difference is that I go backwards through the directory,
173 * and don't mess with f->f_pos, but the idea is the same. Do some
174 * action on each and every entry in the directory.
176 * we're called with i_mutex held, so there are no worries about the directory
177 * changing underneath us.
179 static int __xattr_readdir(struct inode *inode, void *dirent, filldir_t filldir)
181 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
182 INITIALIZE_PATH(path_to_entry);
183 struct buffer_head *bh;
185 struct item_head *ih, tmp_ih;
189 char small_buf[32]; /* avoid kmalloc if we can */
190 struct reiserfs_de_head *deh;
195 struct reiserfs_dir_entry de;
197 /* form key for search the next directory entry using f_pos field of
199 next_pos = max_reiserfs_offset(inode);
203 if (next_pos <= DOT_DOT_OFFSET)
205 make_cpu_key(&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
208 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
210 if (search_res == IO_ERROR) {
211 // FIXME: we could just skip part of directory which could
213 pathrelse(&path_to_entry);
217 if (search_res == NAME_NOT_FOUND)
220 set_de_name_and_namelen(&de);
221 entry_num = de.de_entry_num;
222 deh = &(de.de_deh[entry_num]);
227 if (!is_direntry_le_ih(ih)) {
228 reiserfs_error(inode->i_sb, "jdm-20000",
229 "not direntry %h", ih);
232 copy_item_head(&tmp_ih, ih);
234 /* we must have found item, that is item of this directory, */
235 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
236 "vs-9000: found item %h does not match to dir we readdir %K",
239 if (deh_offset(deh) <= DOT_DOT_OFFSET) {
243 /* look for the previous entry in the directory */
244 next_pos = deh_offset(deh) - 1;
246 if (!de_visible(deh))
247 /* it is hidden entry */
250 d_reclen = entry_length(bh, ih, entry_num);
251 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
252 d_off = deh_offset(deh);
253 d_ino = deh_objectid(deh);
255 if (!d_name[d_reclen - 1])
256 d_reclen = strlen(d_name);
258 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)) {
259 /* too big to send back to VFS */
263 /* Ignore the .reiserfs_priv entry */
264 if (reiserfs_xattrs(inode->i_sb) &&
265 !old_format_only(inode->i_sb) &&
267 le32_to_cpu(INODE_PKEY
268 (REISERFS_SB(inode->i_sb)->priv_root->d_inode)->
272 if (d_reclen <= 32) {
273 local_buf = small_buf;
275 local_buf = kmalloc(d_reclen, GFP_NOFS);
277 pathrelse(&path_to_entry);
280 if (item_moved(&tmp_ih, &path_to_entry)) {
283 /* sigh, must retry. Do this same offset again */
289 // Note, that we copy name to user space via temporary
290 // buffer (local_buf) because filldir will block if
291 // user space buffer is swapped out. At that time
292 // entry can move to somewhere else
293 memcpy(local_buf, d_name, d_reclen);
295 /* the filldir function might need to start transactions,
296 * or do who knows what. Release the path now that we've
297 * copied all the important stuff out of the deh
299 pathrelse(&path_to_entry);
301 if (filldir(dirent, local_buf, d_reclen, d_off, d_ino,
303 if (local_buf != small_buf) {
308 if (local_buf != small_buf) {
314 pathrelse(&path_to_entry);
319 * this could be done with dedicated readdir ops for the xattr files,
320 * but I want to get something working asap
321 * this is stolen from vfs_readdir
325 int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
328 if (!IS_DEADDIR(inode)) {
330 res = __xattr_readdir(inode, buf, filler);
337 __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
339 struct dentry *dentry;
340 struct inode *dir = xadir->d_inode;
343 dentry = lookup_one_len(name, xadir, namelen);
344 if (IS_ERR(dentry)) {
345 err = PTR_ERR(dentry);
347 } else if (!dentry->d_inode) {
352 /* Skip directories.. */
353 if (S_ISDIR(dentry->d_inode->i_mode))
356 if (!IS_PRIVATE(dentry->d_inode)) {
357 reiserfs_error(dir->i_sb, "jdm-20003",
358 "OID %08x [%.*s/%.*s] doesn't have "
359 "priv flag set [parent is %sset].",
360 le32_to_cpu(INODE_PKEY(dentry->d_inode)->
361 k_objectid), xadir->d_name.len,
362 xadir->d_name.name, namelen, name,
363 IS_PRIVATE(xadir->d_inode) ? "" :
369 err = xattr_unlink(dir, dentry);
378 /* The following are side effects of other operations that aren't explicitly
379 * modifying extended attributes. This includes operations such as permissions
380 * or ownership changes, object deletions, etc. */
383 reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
384 loff_t offset, u64 ino, unsigned int d_type)
386 struct dentry *xadir = (struct dentry *)buf;
388 return __reiserfs_xattr_del(xadir, name, namelen);
392 /* This is called w/ inode->i_mutex downed */
393 int reiserfs_delete_xattrs(struct inode *inode)
395 struct dentry *dir, *root;
398 /* Skip out, an xattr has no xattrs associated with it */
399 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
402 reiserfs_read_lock_xattrs(inode->i_sb);
403 dir = open_xa_dir(inode, XATTR_REPLACE);
404 reiserfs_read_unlock_xattrs(inode->i_sb);
408 } else if (!dir->d_inode) {
413 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
414 err = xattr_readdir(dir->d_inode, reiserfs_delete_xattrs_filler, dir);
415 mutex_unlock(&dir->d_inode->i_mutex);
419 /* Leftovers besides . and .. -- that's not good. */
420 if (dir->d_inode->i_nlink <= 2) {
421 root = open_xa_root(inode->i_sb, XATTR_REPLACE);
422 reiserfs_write_lock_xattrs(inode->i_sb);
423 mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_XATTR);
424 err = xattr_rmdir(root->d_inode, dir);
425 mutex_unlock(&root->d_inode->i_mutex);
426 reiserfs_write_unlock_xattrs(inode->i_sb);
429 reiserfs_warning(inode->i_sb, "jdm-20006",
430 "Couldn't remove all entries in directory");
438 REISERFS_I(inode)->i_flags =
439 REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
443 struct reiserfs_chown_buf {
445 struct dentry *xadir;
449 /* XXX: If there is a better way to do this, I'd love to hear about it */
451 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
452 loff_t offset, u64 ino, unsigned int d_type)
454 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
455 struct dentry *xafile, *xadir = chown_buf->xadir;
456 struct iattr *attrs = chown_buf->attrs;
459 xafile = lookup_one_len(name, xadir, namelen);
461 return PTR_ERR(xafile);
462 else if (!xafile->d_inode) {
467 if (!S_ISDIR(xafile->d_inode->i_mode)) {
468 mutex_lock_nested(&xafile->d_inode->i_mutex, I_MUTEX_CHILD);
469 err = notify_change(xafile, attrs);
470 mutex_unlock(&xafile->d_inode->i_mutex);
477 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
481 struct reiserfs_chown_buf buf;
482 unsigned int ia_valid = attrs->ia_valid;
484 /* Skip out, an xattr has no xattrs associated with it */
485 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
488 reiserfs_read_lock_xattrs(inode->i_sb);
489 dir = open_xa_dir(inode, XATTR_REPLACE);
490 reiserfs_read_unlock_xattrs(inode->i_sb);
492 if (PTR_ERR(dir) != -ENODATA)
495 } else if (!dir->d_inode)
498 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
503 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
504 err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
507 err = notify_change(dir, attrs);
508 mutex_unlock(&dir->d_inode->i_mutex);
510 attrs->ia_valid = ia_valid;
517 #ifdef CONFIG_REISERFS_FS_XATTR
518 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
521 /* Returns a dentry corresponding to a specific extended attribute file
522 * for the inode. If flags allow, the file is created. Otherwise, a
523 * valid or negative dentry, or an error is returned. */
524 static struct dentry *get_xa_file_dentry(const struct inode *inode,
525 const char *name, int flags)
527 struct dentry *xadir, *xafile;
530 xadir = open_xa_dir(inode, flags);
532 return ERR_CAST(xadir);
534 xafile = lookup_one_len(name, xadir, strlen(name));
535 if (IS_ERR(xafile)) {
536 err = PTR_ERR(xafile);
540 if (xafile->d_inode && (flags & XATTR_CREATE))
543 if (!xafile->d_inode) {
545 if (xattr_may_create(flags)) {
546 mutex_lock_nested(&xadir->d_inode->i_mutex,
548 err = xattr_create(xadir->d_inode, xafile,
550 mutex_unlock(&xadir->d_inode->i_mutex);
563 /* Internal operations on file data */
564 static inline void reiserfs_put_page(struct page *page)
567 page_cache_release(page);
570 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
572 struct address_space *mapping = dir->i_mapping;
574 /* We can deadlock if we try to free dentries,
575 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
576 mapping_set_gfp_mask(mapping, GFP_NOFS);
577 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
586 reiserfs_put_page(page);
587 return ERR_PTR(-EIO);
590 static inline __u32 xattr_hash(const char *msg, int len)
592 return csum_partial(msg, len, 0);
595 int reiserfs_commit_write(struct file *f, struct page *page,
596 unsigned from, unsigned to);
597 int reiserfs_prepare_write(struct file *f, struct page *page,
598 unsigned from, unsigned to);
601 /* Generic extended attribute operations that can be used by xa plugins */
604 * inode->i_mutex: down
607 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
608 size_t buffer_size, int flags)
611 struct dentry *dentry;
615 size_t buffer_pos = 0;
616 struct iattr newattrs;
619 if (get_inode_sd_version(inode) == STAT_DATA_V1)
622 /* Empty xattrs are ok, they're just empty files, no hash */
623 if (buffer && buffer_size)
624 xahash = xattr_hash(buffer, buffer_size);
626 dentry = get_xa_file_dentry(inode, name, flags);
627 if (IS_ERR(dentry)) {
628 err = PTR_ERR(dentry);
632 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
634 /* Resize it so we're ok to write there */
635 newattrs.ia_size = buffer_size;
636 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
637 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
638 err = notify_change(dentry, &newattrs);
639 mutex_unlock(&dentry->d_inode->i_mutex);
643 while (buffer_pos < buffer_size || buffer_pos == 0) {
646 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
647 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
648 chunk = PAGE_CACHE_SIZE;
650 chunk = buffer_size - buffer_pos;
652 page = reiserfs_get_page(dentry->d_inode, file_pos);
659 data = page_address(page);
662 struct reiserfs_xattr_header *rxh;
663 skip = file_pos = sizeof(struct reiserfs_xattr_header);
664 if (chunk + skip > PAGE_CACHE_SIZE)
665 chunk = PAGE_CACHE_SIZE - skip;
666 rxh = (struct reiserfs_xattr_header *)data;
667 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
668 rxh->h_hash = cpu_to_le32(xahash);
671 err = reiserfs_prepare_write(NULL, page, page_offset,
672 page_offset + chunk + skip);
675 memcpy(data + skip, buffer + buffer_pos, chunk);
676 err = reiserfs_commit_write(NULL, page, page_offset,
677 page_offset + chunk +
681 reiserfs_put_page(page);
685 if (err || buffer_size == 0 || !buffer)
689 /* We can't mark the inode dirty if it's not hashed. This is the case
690 * when we're inheriting the default ACL. If we dirty it, the inode
691 * gets marked dirty, but won't (ever) make it onto the dirty list until
692 * it's synced explicitly to clear I_DIRTY. This is bad. */
693 if (!hlist_unhashed(&inode->i_hash)) {
694 inode->i_ctime = CURRENT_TIME_SEC;
695 mark_inode_dirty(inode);
706 * inode->i_mutex: down
709 reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
713 struct dentry *dentry;
716 size_t buffer_pos = 0;
723 /* We can't have xattrs attached to v1 items since they don't have
724 * generation numbers */
725 if (get_inode_sd_version(inode) == STAT_DATA_V1)
728 dentry = get_xa_file_dentry(inode, name, XATTR_REPLACE);
729 if (IS_ERR(dentry)) {
730 err = PTR_ERR(dentry);
734 isize = i_size_read(dentry->d_inode);
735 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
737 /* Just return the size needed */
738 if (buffer == NULL) {
739 err = isize - sizeof(struct reiserfs_xattr_header);
743 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
748 while (file_pos < isize) {
752 if (isize - file_pos > PAGE_CACHE_SIZE)
753 chunk = PAGE_CACHE_SIZE;
755 chunk = isize - file_pos;
757 page = reiserfs_get_page(dentry->d_inode, file_pos);
764 data = page_address(page);
766 struct reiserfs_xattr_header *rxh =
767 (struct reiserfs_xattr_header *)data;
768 skip = file_pos = sizeof(struct reiserfs_xattr_header);
770 /* Magic doesn't match up.. */
771 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
773 reiserfs_put_page(page);
774 reiserfs_warning(inode->i_sb, "jdm-20001",
775 "Invalid magic for xattr (%s) "
776 "associated with %k", name,
781 hash = le32_to_cpu(rxh->h_hash);
783 memcpy(buffer + buffer_pos, data + skip, chunk);
785 reiserfs_put_page(page);
790 err = isize - sizeof(struct reiserfs_xattr_header);
792 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
794 reiserfs_warning(inode->i_sb, "jdm-20002",
795 "Invalid hash for xattr (%s) associated "
796 "with %k", name, INODE_PKEY(inode));
807 int reiserfs_xattr_del(struct inode *inode, const char *name)
812 dir = open_xa_dir(inode, XATTR_REPLACE);
818 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
819 err = __reiserfs_xattr_del(dir, name, strlen(name));
820 mutex_unlock(&dir->d_inode->i_mutex);
824 inode->i_ctime = CURRENT_TIME_SEC;
825 mark_inode_dirty(inode);
832 /* Actual operations that are exported to VFS-land */
834 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char *);
836 * Inode operation getxattr()
837 * Preliminary locking: we down dentry->d_inode->i_mutex
840 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
843 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
846 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
847 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
850 reiserfs_read_lock_xattr_i(dentry->d_inode);
851 reiserfs_read_lock_xattrs(dentry->d_sb);
852 err = xah->get(dentry->d_inode, name, buffer, size);
853 reiserfs_read_unlock_xattrs(dentry->d_sb);
854 reiserfs_read_unlock_xattr_i(dentry->d_inode);
859 * Inode operation setxattr()
861 * dentry->d_inode->i_mutex down
864 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
865 size_t size, int flags)
867 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
871 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
872 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
875 reiserfs_write_lock_xattr_i(dentry->d_inode);
876 lock = !has_xattr_dir(dentry->d_inode);
878 reiserfs_write_lock_xattrs(dentry->d_sb);
880 reiserfs_read_lock_xattrs(dentry->d_sb);
881 err = xah->set(dentry->d_inode, name, value, size, flags);
883 reiserfs_write_unlock_xattrs(dentry->d_sb);
885 reiserfs_read_unlock_xattrs(dentry->d_sb);
886 reiserfs_write_unlock_xattr_i(dentry->d_inode);
891 * Inode operation removexattr()
893 * dentry->d_inode->i_mutex down
895 int reiserfs_removexattr(struct dentry *dentry, const char *name)
898 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
900 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
901 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
904 reiserfs_write_lock_xattr_i(dentry->d_inode);
905 reiserfs_read_lock_xattrs(dentry->d_sb);
907 /* Deletion pre-operation */
909 err = xah->del(dentry->d_inode, name);
914 err = reiserfs_xattr_del(dentry->d_inode, name);
916 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
917 mark_inode_dirty(dentry->d_inode);
920 reiserfs_read_unlock_xattrs(dentry->d_sb);
921 reiserfs_write_unlock_xattr_i(dentry->d_inode);
925 /* This is what filldir will use:
926 * r_pos will always contain the amount of space required for the entire
927 * list. If r_pos becomes larger than r_size, we need more space and we
928 * return an error indicating this. If r_pos is less than r_size, then we've
929 * filled the buffer successfully and we return success */
930 struct reiserfs_listxattr_buf {
934 struct inode *r_inode;
938 reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
939 loff_t offset, u64 ino, unsigned int d_type)
941 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
944 || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
945 struct reiserfs_xattr_handler *xah =
946 find_xattr_handler_prefix(name);
948 return 0; /* Unsupported xattr name, skip it */
950 /* We call ->list() twice because the operation isn't required to just
951 * return the name back - we want to make sure we have enough space */
952 len += xah->list(b->r_inode, name, namelen, NULL);
955 if (b->r_pos + len + 1 <= b->r_size) {
956 char *p = b->r_buf + b->r_pos;
957 p += xah->list(b->r_inode, name, namelen, p);
968 * Inode operation listxattr()
970 * Preliminary locking: we down dentry->d_inode->i_mutex
972 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
976 struct reiserfs_listxattr_buf buf;
978 if (!dentry->d_inode)
981 if (!reiserfs_xattrs(dentry->d_sb) ||
982 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
985 reiserfs_read_lock_xattr_i(dentry->d_inode);
986 reiserfs_read_lock_xattrs(dentry->d_sb);
987 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
988 reiserfs_read_unlock_xattrs(dentry->d_sb);
992 err = 0; /* Not an error if there aren't any xattrs */
997 buf.r_size = buffer ? size : 0;
999 buf.r_inode = dentry->d_inode;
1001 REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
1003 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
1004 err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
1005 mutex_unlock(&dir->d_inode->i_mutex);
1009 if (buf.r_pos > buf.r_size && buffer != NULL)
1018 reiserfs_read_unlock_xattr_i(dentry->d_inode);
1022 /* This is the implementation for the xattr plugin infrastructure */
1023 static LIST_HEAD(xattr_handlers);
1024 static DEFINE_RWLOCK(handler_lock);
1026 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
1029 struct reiserfs_xattr_handler *xah = NULL;
1030 struct list_head *p;
1032 read_lock(&handler_lock);
1033 list_for_each(p, &xattr_handlers) {
1034 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1035 if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
1040 read_unlock(&handler_lock);
1044 static void __unregister_handlers(void)
1046 struct reiserfs_xattr_handler *xah;
1047 struct list_head *p, *tmp;
1049 list_for_each_safe(p, tmp, &xattr_handlers) {
1050 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1056 INIT_LIST_HEAD(&xattr_handlers);
1059 int __init reiserfs_xattr_register_handlers(void)
1062 struct reiserfs_xattr_handler *xah;
1063 struct list_head *p;
1065 write_lock(&handler_lock);
1067 /* If we're already initialized, nothing to do */
1068 if (!list_empty(&xattr_handlers)) {
1069 write_unlock(&handler_lock);
1073 /* Add the handlers */
1074 list_add_tail(&user_handler.handlers, &xattr_handlers);
1075 list_add_tail(&trusted_handler.handlers, &xattr_handlers);
1076 #ifdef CONFIG_REISERFS_FS_SECURITY
1077 list_add_tail(&security_handler.handlers, &xattr_handlers);
1079 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1080 list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
1081 list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
1084 /* Run initializers, if available */
1085 list_for_each(p, &xattr_handlers) {
1086 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1096 /* Clean up other handlers, if any failed */
1098 __unregister_handlers();
1100 write_unlock(&handler_lock);
1104 void reiserfs_xattr_unregister_handlers(void)
1106 write_lock(&handler_lock);
1107 __unregister_handlers();
1108 write_unlock(&handler_lock);
1111 static int reiserfs_check_acl(struct inode *inode, int mask)
1113 struct posix_acl *acl;
1114 int error = -EAGAIN; /* do regular unix permission checks by default */
1116 reiserfs_read_lock_xattr_i(inode);
1117 reiserfs_read_lock_xattrs(inode->i_sb);
1119 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1121 reiserfs_read_unlock_xattrs(inode->i_sb);
1122 reiserfs_read_unlock_xattr_i(inode);
1126 error = posix_acl_permission(inode, acl, mask);
1127 posix_acl_release(acl);
1128 } else if (PTR_ERR(acl) != -ENODATA)
1129 error = PTR_ERR(acl);
1135 int reiserfs_permission(struct inode *inode, int mask)
1138 * We don't do permission checks on the internal objects.
1139 * Permissions are determined by the "owning" object.
1141 if (IS_PRIVATE(inode))
1144 * Stat data v1 doesn't support ACLs.
1146 if (get_inode_sd_version(inode) == STAT_DATA_V1)
1147 return generic_permission(inode, mask, NULL);
1149 return generic_permission(inode, mask, reiserfs_check_acl);
1152 static int create_privroot(struct dentry *dentry)
1155 struct inode *inode = dentry->d_parent->d_inode;
1156 mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
1157 err = xattr_mkdir(inode, dentry, 0700);
1158 mutex_unlock(&inode->i_mutex);
1164 if (dentry && dentry->d_inode)
1165 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
1166 "storage.\n", PRIVROOT_NAME);
1171 static int xattr_mount_check(struct super_block *s)
1173 /* We need generation numbers to ensure that the oid mapping is correct
1174 * v3.5 filesystems don't have them. */
1175 if (!old_format_only(s)) {
1176 set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1177 } else if (reiserfs_xattrs_optional(s)) {
1178 /* Old format filesystem, but optional xattrs have been enabled
1179 * at mount time. Error out. */
1180 reiserfs_warning(s, "jdm-20005",
1181 "xattrs/ACLs not supported on pre v3.6 "
1182 "format filesystem. Failing mount.");
1185 /* Old format filesystem, but no optional xattrs have
1186 * been enabled. This means we silently disable xattrs
1187 * on the filesystem. */
1188 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1195 int __init reiserfs_xattr_register_handlers(void) { return 0; }
1196 void reiserfs_xattr_unregister_handlers(void) {}
1199 /* This will catch lookups from the fs root to .reiserfs_priv */
1201 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1203 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1204 if (name->len == priv_root->d_name.len &&
1205 name->hash == priv_root->d_name.hash &&
1206 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1208 } else if (q1->len == name->len &&
1209 !memcmp(q1->name, name->name, name->len))
1214 static struct dentry_operations xattr_lookup_poison_ops = {
1215 .d_compare = xattr_lookup_poison,
1218 /* We need to take a copy of the mount flags since things like
1219 * MS_RDONLY don't get set until *after* we're called.
1220 * mount_flags != mount_options */
1221 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1225 #ifdef CONFIG_REISERFS_FS_XATTR
1226 err = xattr_mount_check(s);
1231 /* If we don't have the privroot located yet - go find it */
1232 if (!REISERFS_SB(s)->priv_root) {
1233 struct dentry *dentry;
1234 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1235 strlen(PRIVROOT_NAME));
1236 if (!IS_ERR(dentry)) {
1237 #ifdef CONFIG_REISERFS_FS_XATTR
1238 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode)
1239 err = create_privroot(dentry);
1241 if (!dentry->d_inode) {
1246 err = PTR_ERR(dentry);
1248 if (!err && dentry) {
1249 s->s_root->d_op = &xattr_lookup_poison_ops;
1250 dentry->d_inode->i_flags |= S_PRIVATE;
1251 REISERFS_SB(s)->priv_root = dentry;
1252 #ifdef CONFIG_REISERFS_FS_XATTR
1253 /* xattrs are unavailable */
1254 } else if (!(mount_flags & MS_RDONLY)) {
1255 /* If we're read-only it just means that the dir
1256 * hasn't been created. Not an error -- just no
1257 * xattrs on the fs. We'll check again if we
1259 reiserfs_warning(s, "jdm-20006",
1260 "xattrs/ACLs enabled and couldn't "
1261 "find/create .reiserfs_priv. "
1268 #ifdef CONFIG_REISERFS_FS_XATTR
1271 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1272 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1273 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1277 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1278 s->s_flags = s->s_flags & ~MS_POSIXACL;
1279 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1280 if (reiserfs_posixacl(s))
1281 s->s_flags |= MS_POSIXACL;