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"
56 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char *);
58 /* Helpers for inode ops. We do this so that we don't have all the VFS
59 * overhead and also for proper i_mutex annotation.
60 * dir->i_mutex must be held for all of them. */
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);
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 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
86 error = dir->i_op->unlink(dir, dentry);
87 mutex_unlock(&dentry->d_inode->i_mutex);
94 static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
97 BUG_ON(!mutex_is_locked(&dir->i_mutex));
100 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
101 dentry_unhash(dentry);
102 error = dir->i_op->rmdir(dir, dentry);
104 dentry->d_inode->i_flags |= S_DEAD;
105 mutex_unlock(&dentry->d_inode->i_mutex);
114 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
116 /* Returns and possibly creates the xattr dir. */
117 static struct dentry *lookup_or_create_dir(struct dentry *parent,
118 const char *name, int flags)
120 struct dentry *dentry;
123 dentry = lookup_one_len(name, parent, strlen(name));
126 else if (!dentry->d_inode) {
129 if (xattr_may_create(flags)) {
130 mutex_lock_nested(&parent->d_inode->i_mutex,
132 err = xattr_mkdir(parent->d_inode, dentry, 0700);
133 mutex_unlock(&parent->d_inode->i_mutex);
138 dentry = ERR_PTR(err);
145 static struct dentry *open_xa_root(struct super_block *sb, int flags)
147 struct dentry *privroot = REISERFS_SB(sb)->priv_root;
149 return ERR_PTR(-ENODATA);
150 return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
153 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
155 struct dentry *xaroot, *xadir;
158 xaroot = open_xa_root(inode->i_sb, flags);
162 snprintf(namebuf, sizeof(namebuf), "%X.%X",
163 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
164 inode->i_generation);
166 xadir = lookup_or_create_dir(xaroot, namebuf, flags);
173 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
174 * we need to drop the path before calling the filldir struct. That
175 * would be a big performance hit to the non-xattr case, so I've copied
176 * the whole thing for now. --clm
178 * the big difference is that I go backwards through the directory,
179 * and don't mess with f->f_pos, but the idea is the same. Do some
180 * action on each and every entry in the directory.
182 * we're called with i_mutex held, so there are no worries about the directory
183 * changing underneath us.
185 static int __xattr_readdir(struct inode *inode, void *dirent, filldir_t filldir)
187 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
188 INITIALIZE_PATH(path_to_entry);
189 struct buffer_head *bh;
191 struct item_head *ih, tmp_ih;
195 char small_buf[32]; /* avoid kmalloc if we can */
196 struct reiserfs_de_head *deh;
201 struct reiserfs_dir_entry de;
203 /* form key for search the next directory entry using f_pos field of
205 next_pos = max_reiserfs_offset(inode);
209 if (next_pos <= DOT_DOT_OFFSET)
211 make_cpu_key(&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
214 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
216 if (search_res == IO_ERROR) {
217 // FIXME: we could just skip part of directory which could
219 pathrelse(&path_to_entry);
223 if (search_res == NAME_NOT_FOUND)
226 set_de_name_and_namelen(&de);
227 entry_num = de.de_entry_num;
228 deh = &(de.de_deh[entry_num]);
233 if (!is_direntry_le_ih(ih)) {
234 reiserfs_error(inode->i_sb, "jdm-20000",
235 "not direntry %h", ih);
238 copy_item_head(&tmp_ih, ih);
240 /* we must have found item, that is item of this directory, */
241 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
242 "vs-9000: found item %h does not match to dir we readdir %K",
245 if (deh_offset(deh) <= DOT_DOT_OFFSET) {
249 /* look for the previous entry in the directory */
250 next_pos = deh_offset(deh) - 1;
252 if (!de_visible(deh))
253 /* it is hidden entry */
256 d_reclen = entry_length(bh, ih, entry_num);
257 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
258 d_off = deh_offset(deh);
259 d_ino = deh_objectid(deh);
261 if (!d_name[d_reclen - 1])
262 d_reclen = strlen(d_name);
264 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)) {
265 /* too big to send back to VFS */
269 /* Ignore the .reiserfs_priv entry */
270 if (reiserfs_xattrs(inode->i_sb) &&
271 !old_format_only(inode->i_sb) &&
273 le32_to_cpu(INODE_PKEY
274 (REISERFS_SB(inode->i_sb)->priv_root->d_inode)->
278 if (d_reclen <= 32) {
279 local_buf = small_buf;
281 local_buf = kmalloc(d_reclen, GFP_NOFS);
283 pathrelse(&path_to_entry);
286 if (item_moved(&tmp_ih, &path_to_entry)) {
289 /* sigh, must retry. Do this same offset again */
295 // Note, that we copy name to user space via temporary
296 // buffer (local_buf) because filldir will block if
297 // user space buffer is swapped out. At that time
298 // entry can move to somewhere else
299 memcpy(local_buf, d_name, d_reclen);
301 /* the filldir function might need to start transactions,
302 * or do who knows what. Release the path now that we've
303 * copied all the important stuff out of the deh
305 pathrelse(&path_to_entry);
307 if (filldir(dirent, local_buf, d_reclen, d_off, d_ino,
309 if (local_buf != small_buf) {
314 if (local_buf != small_buf) {
320 pathrelse(&path_to_entry);
325 * this could be done with dedicated readdir ops for the xattr files,
326 * but I want to get something working asap
327 * this is stolen from vfs_readdir
331 int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
334 if (!IS_DEADDIR(inode)) {
336 res = __xattr_readdir(inode, buf, filler);
342 /* expects xadir->d_inode->i_mutex to be locked */
344 __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
346 struct dentry *dentry;
347 struct inode *dir = xadir->d_inode;
349 struct reiserfs_xattr_handler *xah;
351 dentry = lookup_one_len(name, xadir, namelen);
352 if (IS_ERR(dentry)) {
353 err = PTR_ERR(dentry);
355 } else if (!dentry->d_inode) {
360 /* Skip directories.. */
361 if (S_ISDIR(dentry->d_inode->i_mode))
364 if (!IS_PRIVATE(dentry->d_inode)) {
365 reiserfs_error(dir->i_sb, "jdm-20003",
366 "OID %08x [%.*s/%.*s] doesn't have "
367 "priv flag set [parent is %sset].",
368 le32_to_cpu(INODE_PKEY(dentry->d_inode)->
369 k_objectid), xadir->d_name.len,
370 xadir->d_name.name, namelen, name,
371 IS_PRIVATE(xadir->d_inode) ? "" :
377 /* Deletion pre-operation */
378 xah = find_xattr_handler_prefix(name);
379 if (xah && xah->del) {
380 err = xah->del(dentry->d_inode, name);
385 err = xattr_unlink(dir, dentry);
394 /* The following are side effects of other operations that aren't explicitly
395 * modifying extended attributes. This includes operations such as permissions
396 * or ownership changes, object deletions, etc. */
399 reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
400 loff_t offset, u64 ino, unsigned int d_type)
402 struct dentry *xadir = (struct dentry *)buf;
404 return __reiserfs_xattr_del(xadir, name, namelen);
408 /* This is called w/ inode->i_mutex downed */
409 int reiserfs_delete_xattrs(struct inode *inode)
412 struct dentry *dir, *root;
413 struct reiserfs_transaction_handle th;
414 int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
415 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb);
417 /* Skip out, an xattr has no xattrs associated with it */
418 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
421 dir = open_xa_dir(inode, XATTR_REPLACE);
425 } else if (!dir->d_inode) {
430 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
431 err = xattr_readdir(dir->d_inode, reiserfs_delete_xattrs_filler, dir);
432 mutex_unlock(&dir->d_inode->i_mutex);
438 root = dget(dir->d_parent);
441 /* We start a transaction here to avoid a ABBA situation
442 * between the xattr root's i_mutex and the journal lock.
443 * Inode creation will inherit an ACL, which requires a
444 * lookup. The lookup locks the xattr root i_mutex with a
445 * transaction open. Inode deletion takes teh xattr root
446 * i_mutex to delete the directory and then starts a
447 * transaction inside it. Boom. This doesn't incur much
448 * additional overhead since the reiserfs_rmdir transaction
449 * will just nest inside the outer transaction. */
450 err = journal_begin(&th, inode->i_sb, blocks);
453 mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_XATTR);
454 err = xattr_rmdir(root->d_inode, dir);
455 jerror = journal_end(&th, inode->i_sb, blocks);
456 mutex_unlock(&root->d_inode->i_mutex);
463 reiserfs_warning(inode->i_sb, "jdm-20004",
464 "Couldn't remove all xattrs (%d)\n", err);
468 struct reiserfs_chown_buf {
470 struct dentry *xadir;
474 /* XXX: If there is a better way to do this, I'd love to hear about it */
476 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
477 loff_t offset, u64 ino, unsigned int d_type)
479 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
480 struct dentry *xafile, *xadir = chown_buf->xadir;
481 struct iattr *attrs = chown_buf->attrs;
484 xafile = lookup_one_len(name, xadir, namelen);
486 return PTR_ERR(xafile);
487 else if (!xafile->d_inode) {
492 if (!S_ISDIR(xafile->d_inode->i_mode)) {
493 mutex_lock_nested(&xafile->d_inode->i_mutex, I_MUTEX_CHILD);
494 err = reiserfs_setattr(xafile, attrs);
495 mutex_unlock(&xafile->d_inode->i_mutex);
502 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
506 struct reiserfs_chown_buf buf;
507 unsigned int ia_valid = attrs->ia_valid;
509 /* Skip out, an xattr has no xattrs associated with it */
510 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
513 dir = open_xa_dir(inode, XATTR_REPLACE);
515 if (PTR_ERR(dir) != -ENODATA)
518 } else if (!dir->d_inode)
521 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
526 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
527 err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
530 err = reiserfs_setattr(dir, attrs);
531 mutex_unlock(&dir->d_inode->i_mutex);
533 attrs->ia_valid = ia_valid;
538 reiserfs_warning(inode->i_sb, "jdm-20007",
539 "Couldn't chown all xattrs (%d)\n", err);
543 #ifdef CONFIG_REISERFS_FS_XATTR
544 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
547 /* Returns a dentry corresponding to a specific extended attribute file
548 * for the inode. If flags allow, the file is created. Otherwise, a
549 * valid or negative dentry, or an error is returned. */
550 static struct dentry *get_xa_file_dentry(const struct inode *inode,
551 const char *name, int flags)
553 struct dentry *xadir, *xafile;
556 xadir = open_xa_dir(inode, flags);
558 return ERR_CAST(xadir);
560 xafile = lookup_one_len(name, xadir, strlen(name));
561 if (IS_ERR(xafile)) {
562 err = PTR_ERR(xafile);
566 if (xafile->d_inode && (flags & XATTR_CREATE))
569 if (!xafile->d_inode) {
571 if (xattr_may_create(flags)) {
572 mutex_lock_nested(&xadir->d_inode->i_mutex,
574 err = xattr_create(xadir->d_inode, xafile,
576 mutex_unlock(&xadir->d_inode->i_mutex);
589 /* Internal operations on file data */
590 static inline void reiserfs_put_page(struct page *page)
593 page_cache_release(page);
596 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
598 struct address_space *mapping = dir->i_mapping;
600 /* We can deadlock if we try to free dentries,
601 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
602 mapping_set_gfp_mask(mapping, GFP_NOFS);
603 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
612 reiserfs_put_page(page);
613 return ERR_PTR(-EIO);
616 static inline __u32 xattr_hash(const char *msg, int len)
618 return csum_partial(msg, len, 0);
621 int reiserfs_commit_write(struct file *f, struct page *page,
622 unsigned from, unsigned to);
623 int reiserfs_prepare_write(struct file *f, struct page *page,
624 unsigned from, unsigned to);
627 /* Generic extended attribute operations that can be used by xa plugins */
630 * inode->i_mutex: down
633 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
634 size_t buffer_size, int flags)
637 struct dentry *dentry;
641 size_t buffer_pos = 0;
642 struct iattr newattrs;
645 if (get_inode_sd_version(inode) == STAT_DATA_V1)
649 return reiserfs_xattr_del(inode, name);
651 dentry = get_xa_file_dentry(inode, name, flags);
652 if (IS_ERR(dentry)) {
653 err = PTR_ERR(dentry);
657 down_write(&REISERFS_I(inode)->i_xattr_sem);
659 xahash = xattr_hash(buffer, buffer_size);
661 /* Resize it so we're ok to write there */
662 newattrs.ia_size = buffer_size;
663 newattrs.ia_ctime = current_fs_time(inode->i_sb);
664 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
665 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
666 down_write(&dentry->d_inode->i_alloc_sem);
667 err = reiserfs_setattr(dentry, &newattrs);
668 up_write(&dentry->d_inode->i_alloc_sem);
669 mutex_unlock(&dentry->d_inode->i_mutex);
673 while (buffer_pos < buffer_size || buffer_pos == 0) {
676 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
677 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
678 chunk = PAGE_CACHE_SIZE;
680 chunk = buffer_size - buffer_pos;
682 page = reiserfs_get_page(dentry->d_inode, file_pos);
689 data = page_address(page);
692 struct reiserfs_xattr_header *rxh;
693 skip = file_pos = sizeof(struct reiserfs_xattr_header);
694 if (chunk + skip > PAGE_CACHE_SIZE)
695 chunk = PAGE_CACHE_SIZE - skip;
696 rxh = (struct reiserfs_xattr_header *)data;
697 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
698 rxh->h_hash = cpu_to_le32(xahash);
701 err = reiserfs_prepare_write(NULL, page, page_offset,
702 page_offset + chunk + skip);
705 memcpy(data + skip, buffer + buffer_pos, chunk);
706 err = reiserfs_commit_write(NULL, page, page_offset,
707 page_offset + chunk +
711 reiserfs_put_page(page);
715 if (err || buffer_size == 0 || !buffer)
719 /* We can't mark the inode dirty if it's not hashed. This is the case
720 * when we're inheriting the default ACL. If we dirty it, the inode
721 * gets marked dirty, but won't (ever) make it onto the dirty list until
722 * it's synced explicitly to clear I_DIRTY. This is bad. */
723 if (!hlist_unhashed(&inode->i_hash)) {
724 inode->i_ctime = CURRENT_TIME_SEC;
725 mark_inode_dirty(inode);
729 up_write(&REISERFS_I(inode)->i_xattr_sem);
737 * inode->i_mutex: down
740 reiserfs_xattr_get(const 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 = get_xa_file_dentry(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 int reiserfs_xattr_del(struct inode *inode, const char *name)
845 dir = open_xa_dir(inode, XATTR_REPLACE);
851 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
852 err = __reiserfs_xattr_del(dir, name, strlen(name));
853 mutex_unlock(&dir->d_inode->i_mutex);
857 inode->i_ctime = CURRENT_TIME_SEC;
858 mark_inode_dirty(inode);
865 /* Actual operations that are exported to VFS-land */
867 * Inode operation getxattr()
870 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
873 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
876 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
877 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
880 err = xah->get(dentry->d_inode, name, buffer, size);
885 * Inode operation setxattr()
887 * dentry->d_inode->i_mutex down
890 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
891 size_t size, int flags)
893 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
896 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
897 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
900 err = xah->set(dentry->d_inode, name, value, size, flags);
905 * Inode operation removexattr()
907 * dentry->d_inode->i_mutex down
909 int reiserfs_removexattr(struct dentry *dentry, const char *name)
912 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
914 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
915 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
918 err = reiserfs_xattr_del(dentry->d_inode, name);
920 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
921 mark_inode_dirty(dentry->d_inode);
926 /* This is what filldir will use:
927 * r_pos will always contain the amount of space required for the entire
928 * list. If r_pos becomes larger than r_size, we need more space and we
929 * return an error indicating this. If r_pos is less than r_size, then we've
930 * filled the buffer successfully and we return success */
931 struct reiserfs_listxattr_buf {
935 struct inode *r_inode;
939 reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
940 loff_t offset, u64 ino, unsigned int d_type)
942 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
945 || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
946 struct reiserfs_xattr_handler *xah =
947 find_xattr_handler_prefix(name);
949 return 0; /* Unsupported xattr name, skip it */
951 /* We call ->list() twice because the operation isn't required to just
952 * return the name back - we want to make sure we have enough space */
953 len += xah->list(b->r_inode, name, namelen, NULL);
956 if (b->r_pos + len + 1 <= b->r_size) {
957 char *p = b->r_buf + b->r_pos;
958 p += xah->list(b->r_inode, name, namelen, p);
969 * Inode operation listxattr()
971 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
975 struct reiserfs_listxattr_buf buf;
977 if (!dentry->d_inode)
980 if (!reiserfs_xattrs(dentry->d_sb) ||
981 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
984 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
988 err = 0; /* Not an error if there aren't any xattrs */
993 buf.r_size = buffer ? size : 0;
995 buf.r_inode = dentry->d_inode;
997 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
998 err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
999 mutex_unlock(&dir->d_inode->i_mutex);
1002 if (buf.r_pos > buf.r_size && buffer != NULL)
1013 /* This is the implementation for the xattr plugin infrastructure */
1014 static LIST_HEAD(xattr_handlers);
1015 static DEFINE_RWLOCK(handler_lock);
1017 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
1020 struct reiserfs_xattr_handler *xah = NULL;
1021 struct list_head *p;
1023 read_lock(&handler_lock);
1024 list_for_each(p, &xattr_handlers) {
1025 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1026 if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
1031 read_unlock(&handler_lock);
1035 static void __unregister_handlers(void)
1037 struct reiserfs_xattr_handler *xah;
1038 struct list_head *p, *tmp;
1040 list_for_each_safe(p, tmp, &xattr_handlers) {
1041 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1047 INIT_LIST_HEAD(&xattr_handlers);
1050 int __init reiserfs_xattr_register_handlers(void)
1053 struct reiserfs_xattr_handler *xah;
1054 struct list_head *p;
1056 write_lock(&handler_lock);
1058 /* If we're already initialized, nothing to do */
1059 if (!list_empty(&xattr_handlers)) {
1060 write_unlock(&handler_lock);
1064 /* Add the handlers */
1065 list_add_tail(&user_handler.handlers, &xattr_handlers);
1066 list_add_tail(&trusted_handler.handlers, &xattr_handlers);
1067 #ifdef CONFIG_REISERFS_FS_SECURITY
1068 list_add_tail(&security_handler.handlers, &xattr_handlers);
1070 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1071 list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
1072 list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
1075 /* Run initializers, if available */
1076 list_for_each(p, &xattr_handlers) {
1077 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1087 /* Clean up other handlers, if any failed */
1089 __unregister_handlers();
1091 write_unlock(&handler_lock);
1095 void reiserfs_xattr_unregister_handlers(void)
1097 write_lock(&handler_lock);
1098 __unregister_handlers();
1099 write_unlock(&handler_lock);
1102 static int reiserfs_check_acl(struct inode *inode, int mask)
1104 struct posix_acl *acl;
1105 int error = -EAGAIN; /* do regular unix permission checks by default */
1107 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1111 error = posix_acl_permission(inode, acl, mask);
1112 posix_acl_release(acl);
1113 } else if (PTR_ERR(acl) != -ENODATA)
1114 error = PTR_ERR(acl);
1120 int reiserfs_permission(struct inode *inode, int mask)
1123 * We don't do permission checks on the internal objects.
1124 * Permissions are determined by the "owning" object.
1126 if (IS_PRIVATE(inode))
1129 * Stat data v1 doesn't support ACLs.
1131 if (get_inode_sd_version(inode) == STAT_DATA_V1)
1132 return generic_permission(inode, mask, NULL);
1134 return generic_permission(inode, mask, reiserfs_check_acl);
1137 static int create_privroot(struct dentry *dentry)
1140 struct inode *inode = dentry->d_parent->d_inode;
1141 mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
1142 err = xattr_mkdir(inode, dentry, 0700);
1143 mutex_unlock(&inode->i_mutex);
1149 if (dentry && dentry->d_inode)
1150 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
1151 "storage.\n", PRIVROOT_NAME);
1156 static int xattr_mount_check(struct super_block *s)
1158 /* We need generation numbers to ensure that the oid mapping is correct
1159 * v3.5 filesystems don't have them. */
1160 if (!old_format_only(s)) {
1161 set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1162 } else if (reiserfs_xattrs_optional(s)) {
1163 /* Old format filesystem, but optional xattrs have been enabled
1164 * at mount time. Error out. */
1165 reiserfs_warning(s, "jdm-20005",
1166 "xattrs/ACLs not supported on pre v3.6 "
1167 "format filesystem. Failing mount.");
1170 /* Old format filesystem, but no optional xattrs have
1171 * been enabled. This means we silently disable xattrs
1172 * on the filesystem. */
1173 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1180 int __init reiserfs_xattr_register_handlers(void) { return 0; }
1181 void reiserfs_xattr_unregister_handlers(void) {}
1184 /* This will catch lookups from the fs root to .reiserfs_priv */
1186 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1188 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1189 if (name->len == priv_root->d_name.len &&
1190 name->hash == priv_root->d_name.hash &&
1191 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1193 } else if (q1->len == name->len &&
1194 !memcmp(q1->name, name->name, name->len))
1199 static struct dentry_operations xattr_lookup_poison_ops = {
1200 .d_compare = xattr_lookup_poison,
1203 /* We need to take a copy of the mount flags since things like
1204 * MS_RDONLY don't get set until *after* we're called.
1205 * mount_flags != mount_options */
1206 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1210 #ifdef CONFIG_REISERFS_FS_XATTR
1211 err = xattr_mount_check(s);
1216 /* If we don't have the privroot located yet - go find it */
1217 if (!REISERFS_SB(s)->priv_root) {
1218 struct dentry *dentry;
1219 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1220 strlen(PRIVROOT_NAME));
1221 if (!IS_ERR(dentry)) {
1222 #ifdef CONFIG_REISERFS_FS_XATTR
1223 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode)
1224 err = create_privroot(dentry);
1226 if (!dentry->d_inode) {
1231 err = PTR_ERR(dentry);
1233 if (!err && dentry) {
1234 s->s_root->d_op = &xattr_lookup_poison_ops;
1235 dentry->d_inode->i_flags |= S_PRIVATE;
1236 REISERFS_SB(s)->priv_root = dentry;
1237 #ifdef CONFIG_REISERFS_FS_XATTR
1238 /* xattrs are unavailable */
1239 } else if (!(mount_flags & MS_RDONLY)) {
1240 /* If we're read-only it just means that the dir
1241 * hasn't been created. Not an error -- just no
1242 * xattrs on the fs. We'll check again if we
1244 reiserfs_warning(s, "jdm-20006",
1245 "xattrs/ACLs enabled and couldn't "
1246 "find/create .reiserfs_priv. "
1253 #ifdef CONFIG_REISERFS_FS_XATTR
1256 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1257 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1258 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1262 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1263 s->s_flags = s->s_flags & ~MS_POSIXACL;
1264 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1265 if (reiserfs_posixacl(s))
1266 s->s_flags |= MS_POSIXACL;