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_I(inode)->i_flags =
464 REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
466 reiserfs_warning(inode->i_sb, "jdm-20004",
467 "Couldn't remove all xattrs (%d)\n", err);
471 struct reiserfs_chown_buf {
473 struct dentry *xadir;
477 /* XXX: If there is a better way to do this, I'd love to hear about it */
479 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
480 loff_t offset, u64 ino, unsigned int d_type)
482 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
483 struct dentry *xafile, *xadir = chown_buf->xadir;
484 struct iattr *attrs = chown_buf->attrs;
487 xafile = lookup_one_len(name, xadir, namelen);
489 return PTR_ERR(xafile);
490 else if (!xafile->d_inode) {
495 if (!S_ISDIR(xafile->d_inode->i_mode)) {
496 mutex_lock_nested(&xafile->d_inode->i_mutex, I_MUTEX_CHILD);
497 err = reiserfs_setattr(xafile, attrs);
498 mutex_unlock(&xafile->d_inode->i_mutex);
505 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
509 struct reiserfs_chown_buf buf;
510 unsigned int ia_valid = attrs->ia_valid;
512 /* Skip out, an xattr has no xattrs associated with it */
513 if (IS_PRIVATE(inode) || get_inode_sd_version(inode) == STAT_DATA_V1)
516 dir = open_xa_dir(inode, XATTR_REPLACE);
518 if (PTR_ERR(dir) != -ENODATA)
521 } else if (!dir->d_inode)
524 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
529 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
530 err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
533 err = reiserfs_setattr(dir, attrs);
534 mutex_unlock(&dir->d_inode->i_mutex);
536 attrs->ia_valid = ia_valid;
541 reiserfs_warning(inode->i_sb, "jdm-20007",
542 "Couldn't chown all xattrs (%d)\n", err);
546 #ifdef CONFIG_REISERFS_FS_XATTR
547 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
550 /* Returns a dentry corresponding to a specific extended attribute file
551 * for the inode. If flags allow, the file is created. Otherwise, a
552 * valid or negative dentry, or an error is returned. */
553 static struct dentry *get_xa_file_dentry(const struct inode *inode,
554 const char *name, int flags)
556 struct dentry *xadir, *xafile;
559 xadir = open_xa_dir(inode, flags);
561 return ERR_CAST(xadir);
563 xafile = lookup_one_len(name, xadir, strlen(name));
564 if (IS_ERR(xafile)) {
565 err = PTR_ERR(xafile);
569 if (xafile->d_inode && (flags & XATTR_CREATE))
572 if (!xafile->d_inode) {
574 if (xattr_may_create(flags)) {
575 mutex_lock_nested(&xadir->d_inode->i_mutex,
577 err = xattr_create(xadir->d_inode, xafile,
579 mutex_unlock(&xadir->d_inode->i_mutex);
592 /* Internal operations on file data */
593 static inline void reiserfs_put_page(struct page *page)
596 page_cache_release(page);
599 static struct page *reiserfs_get_page(struct inode *dir, size_t n)
601 struct address_space *mapping = dir->i_mapping;
603 /* We can deadlock if we try to free dentries,
604 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
605 mapping_set_gfp_mask(mapping, GFP_NOFS);
606 page = read_mapping_page(mapping, n >> PAGE_CACHE_SHIFT, NULL);
615 reiserfs_put_page(page);
616 return ERR_PTR(-EIO);
619 static inline __u32 xattr_hash(const char *msg, int len)
621 return csum_partial(msg, len, 0);
624 int reiserfs_commit_write(struct file *f, struct page *page,
625 unsigned from, unsigned to);
626 int reiserfs_prepare_write(struct file *f, struct page *page,
627 unsigned from, unsigned to);
630 /* Generic extended attribute operations that can be used by xa plugins */
633 * inode->i_mutex: down
636 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
637 size_t buffer_size, int flags)
640 struct dentry *dentry;
644 size_t buffer_pos = 0;
645 struct iattr newattrs;
648 if (get_inode_sd_version(inode) == STAT_DATA_V1)
652 return reiserfs_xattr_del(inode, name);
654 dentry = get_xa_file_dentry(inode, name, flags);
655 if (IS_ERR(dentry)) {
656 err = PTR_ERR(dentry);
660 down_write(&REISERFS_I(inode)->i_xattr_sem);
662 xahash = xattr_hash(buffer, buffer_size);
663 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
665 /* Resize it so we're ok to write there */
666 newattrs.ia_size = buffer_size;
667 newattrs.ia_ctime = current_fs_time(inode->i_sb);
668 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
669 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
670 down_write(&dentry->d_inode->i_alloc_sem);
671 err = reiserfs_setattr(dentry, &newattrs);
672 up_write(&dentry->d_inode->i_alloc_sem);
673 mutex_unlock(&dentry->d_inode->i_mutex);
677 while (buffer_pos < buffer_size || buffer_pos == 0) {
680 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
681 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
682 chunk = PAGE_CACHE_SIZE;
684 chunk = buffer_size - buffer_pos;
686 page = reiserfs_get_page(dentry->d_inode, file_pos);
693 data = page_address(page);
696 struct reiserfs_xattr_header *rxh;
697 skip = file_pos = sizeof(struct reiserfs_xattr_header);
698 if (chunk + skip > PAGE_CACHE_SIZE)
699 chunk = PAGE_CACHE_SIZE - skip;
700 rxh = (struct reiserfs_xattr_header *)data;
701 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
702 rxh->h_hash = cpu_to_le32(xahash);
705 err = reiserfs_prepare_write(NULL, page, page_offset,
706 page_offset + chunk + skip);
709 memcpy(data + skip, buffer + buffer_pos, chunk);
710 err = reiserfs_commit_write(NULL, page, page_offset,
711 page_offset + chunk +
715 reiserfs_put_page(page);
719 if (err || buffer_size == 0 || !buffer)
723 /* We can't mark the inode dirty if it's not hashed. This is the case
724 * when we're inheriting the default ACL. If we dirty it, the inode
725 * gets marked dirty, but won't (ever) make it onto the dirty list until
726 * it's synced explicitly to clear I_DIRTY. This is bad. */
727 if (!hlist_unhashed(&inode->i_hash)) {
728 inode->i_ctime = CURRENT_TIME_SEC;
729 mark_inode_dirty(inode);
733 up_write(&REISERFS_I(inode)->i_xattr_sem);
741 * inode->i_mutex: down
744 reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
748 struct dentry *dentry;
751 size_t buffer_pos = 0;
758 /* We can't have xattrs attached to v1 items since they don't have
759 * generation numbers */
760 if (get_inode_sd_version(inode) == STAT_DATA_V1)
763 dentry = get_xa_file_dentry(inode, name, XATTR_REPLACE);
764 if (IS_ERR(dentry)) {
765 err = PTR_ERR(dentry);
769 down_read(&REISERFS_I(inode)->i_xattr_sem);
771 isize = i_size_read(dentry->d_inode);
772 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
774 /* Just return the size needed */
775 if (buffer == NULL) {
776 err = isize - sizeof(struct reiserfs_xattr_header);
780 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
785 while (file_pos < isize) {
789 if (isize - file_pos > PAGE_CACHE_SIZE)
790 chunk = PAGE_CACHE_SIZE;
792 chunk = isize - file_pos;
794 page = reiserfs_get_page(dentry->d_inode, file_pos);
801 data = page_address(page);
803 struct reiserfs_xattr_header *rxh =
804 (struct reiserfs_xattr_header *)data;
805 skip = file_pos = sizeof(struct reiserfs_xattr_header);
807 /* Magic doesn't match up.. */
808 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
810 reiserfs_put_page(page);
811 reiserfs_warning(inode->i_sb, "jdm-20001",
812 "Invalid magic for xattr (%s) "
813 "associated with %k", name,
818 hash = le32_to_cpu(rxh->h_hash);
820 memcpy(buffer + buffer_pos, data + skip, chunk);
822 reiserfs_put_page(page);
827 err = isize - sizeof(struct reiserfs_xattr_header);
829 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
831 reiserfs_warning(inode->i_sb, "jdm-20002",
832 "Invalid hash for xattr (%s) associated "
833 "with %k", name, INODE_PKEY(inode));
838 up_read(&REISERFS_I(inode)->i_xattr_sem);
845 int reiserfs_xattr_del(struct inode *inode, const char *name)
850 dir = open_xa_dir(inode, XATTR_REPLACE);
856 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
857 err = __reiserfs_xattr_del(dir, name, strlen(name));
858 mutex_unlock(&dir->d_inode->i_mutex);
862 inode->i_ctime = CURRENT_TIME_SEC;
863 mark_inode_dirty(inode);
870 /* Actual operations that are exported to VFS-land */
872 * Inode operation getxattr()
875 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
878 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
881 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
882 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
885 err = xah->get(dentry->d_inode, name, buffer, size);
890 * Inode operation setxattr()
892 * dentry->d_inode->i_mutex down
895 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
896 size_t size, int flags)
898 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
901 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
902 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
905 err = xah->set(dentry->d_inode, name, value, size, flags);
910 * Inode operation removexattr()
912 * dentry->d_inode->i_mutex down
914 int reiserfs_removexattr(struct dentry *dentry, const char *name)
917 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
919 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
920 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
923 err = reiserfs_xattr_del(dentry->d_inode, name);
925 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
926 mark_inode_dirty(dentry->d_inode);
931 /* This is what filldir will use:
932 * r_pos will always contain the amount of space required for the entire
933 * list. If r_pos becomes larger than r_size, we need more space and we
934 * return an error indicating this. If r_pos is less than r_size, then we've
935 * filled the buffer successfully and we return success */
936 struct reiserfs_listxattr_buf {
940 struct inode *r_inode;
944 reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
945 loff_t offset, u64 ino, unsigned int d_type)
947 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
950 || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
951 struct reiserfs_xattr_handler *xah =
952 find_xattr_handler_prefix(name);
954 return 0; /* Unsupported xattr name, skip it */
956 /* We call ->list() twice because the operation isn't required to just
957 * return the name back - we want to make sure we have enough space */
958 len += xah->list(b->r_inode, name, namelen, NULL);
961 if (b->r_pos + len + 1 <= b->r_size) {
962 char *p = b->r_buf + b->r_pos;
963 p += xah->list(b->r_inode, name, namelen, p);
974 * Inode operation listxattr()
976 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
980 struct reiserfs_listxattr_buf buf;
982 if (!dentry->d_inode)
985 if (!reiserfs_xattrs(dentry->d_sb) ||
986 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
989 dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
993 err = 0; /* Not an error if there aren't any xattrs */
998 buf.r_size = buffer ? size : 0;
1000 buf.r_inode = dentry->d_inode;
1002 REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
1004 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
1005 err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
1006 mutex_unlock(&dir->d_inode->i_mutex);
1009 if (buf.r_pos > buf.r_size && buffer != NULL)
1020 /* This is the implementation for the xattr plugin infrastructure */
1021 static LIST_HEAD(xattr_handlers);
1022 static DEFINE_RWLOCK(handler_lock);
1024 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
1027 struct reiserfs_xattr_handler *xah = NULL;
1028 struct list_head *p;
1030 read_lock(&handler_lock);
1031 list_for_each(p, &xattr_handlers) {
1032 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1033 if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
1038 read_unlock(&handler_lock);
1042 static void __unregister_handlers(void)
1044 struct reiserfs_xattr_handler *xah;
1045 struct list_head *p, *tmp;
1047 list_for_each_safe(p, tmp, &xattr_handlers) {
1048 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1054 INIT_LIST_HEAD(&xattr_handlers);
1057 int __init reiserfs_xattr_register_handlers(void)
1060 struct reiserfs_xattr_handler *xah;
1061 struct list_head *p;
1063 write_lock(&handler_lock);
1065 /* If we're already initialized, nothing to do */
1066 if (!list_empty(&xattr_handlers)) {
1067 write_unlock(&handler_lock);
1071 /* Add the handlers */
1072 list_add_tail(&user_handler.handlers, &xattr_handlers);
1073 list_add_tail(&trusted_handler.handlers, &xattr_handlers);
1074 #ifdef CONFIG_REISERFS_FS_SECURITY
1075 list_add_tail(&security_handler.handlers, &xattr_handlers);
1077 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1078 list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
1079 list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
1082 /* Run initializers, if available */
1083 list_for_each(p, &xattr_handlers) {
1084 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1094 /* Clean up other handlers, if any failed */
1096 __unregister_handlers();
1098 write_unlock(&handler_lock);
1102 void reiserfs_xattr_unregister_handlers(void)
1104 write_lock(&handler_lock);
1105 __unregister_handlers();
1106 write_unlock(&handler_lock);
1109 static int reiserfs_check_acl(struct inode *inode, int mask)
1111 struct posix_acl *acl;
1112 int error = -EAGAIN; /* do regular unix permission checks by default */
1114 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1118 error = posix_acl_permission(inode, acl, mask);
1119 posix_acl_release(acl);
1120 } else if (PTR_ERR(acl) != -ENODATA)
1121 error = PTR_ERR(acl);
1127 int reiserfs_permission(struct inode *inode, int mask)
1130 * We don't do permission checks on the internal objects.
1131 * Permissions are determined by the "owning" object.
1133 if (IS_PRIVATE(inode))
1136 * Stat data v1 doesn't support ACLs.
1138 if (get_inode_sd_version(inode) == STAT_DATA_V1)
1139 return generic_permission(inode, mask, NULL);
1141 return generic_permission(inode, mask, reiserfs_check_acl);
1144 static int create_privroot(struct dentry *dentry)
1147 struct inode *inode = dentry->d_parent->d_inode;
1148 mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
1149 err = xattr_mkdir(inode, dentry, 0700);
1150 mutex_unlock(&inode->i_mutex);
1156 if (dentry && dentry->d_inode)
1157 reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
1158 "storage.\n", PRIVROOT_NAME);
1163 static int xattr_mount_check(struct super_block *s)
1165 /* We need generation numbers to ensure that the oid mapping is correct
1166 * v3.5 filesystems don't have them. */
1167 if (!old_format_only(s)) {
1168 set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1169 } else if (reiserfs_xattrs_optional(s)) {
1170 /* Old format filesystem, but optional xattrs have been enabled
1171 * at mount time. Error out. */
1172 reiserfs_warning(s, "jdm-20005",
1173 "xattrs/ACLs not supported on pre v3.6 "
1174 "format filesystem. Failing mount.");
1177 /* Old format filesystem, but no optional xattrs have
1178 * been enabled. This means we silently disable xattrs
1179 * on the filesystem. */
1180 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1187 int __init reiserfs_xattr_register_handlers(void) { return 0; }
1188 void reiserfs_xattr_unregister_handlers(void) {}
1191 /* This will catch lookups from the fs root to .reiserfs_priv */
1193 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1195 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1196 if (name->len == priv_root->d_name.len &&
1197 name->hash == priv_root->d_name.hash &&
1198 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1200 } else if (q1->len == name->len &&
1201 !memcmp(q1->name, name->name, name->len))
1206 static struct dentry_operations xattr_lookup_poison_ops = {
1207 .d_compare = xattr_lookup_poison,
1210 /* We need to take a copy of the mount flags since things like
1211 * MS_RDONLY don't get set until *after* we're called.
1212 * mount_flags != mount_options */
1213 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1217 #ifdef CONFIG_REISERFS_FS_XATTR
1218 err = xattr_mount_check(s);
1223 /* If we don't have the privroot located yet - go find it */
1224 if (!REISERFS_SB(s)->priv_root) {
1225 struct dentry *dentry;
1226 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1227 strlen(PRIVROOT_NAME));
1228 if (!IS_ERR(dentry)) {
1229 #ifdef CONFIG_REISERFS_FS_XATTR
1230 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode)
1231 err = create_privroot(dentry);
1233 if (!dentry->d_inode) {
1238 err = PTR_ERR(dentry);
1240 if (!err && dentry) {
1241 s->s_root->d_op = &xattr_lookup_poison_ops;
1242 dentry->d_inode->i_flags |= S_PRIVATE;
1243 REISERFS_SB(s)->priv_root = dentry;
1244 #ifdef CONFIG_REISERFS_FS_XATTR
1245 /* xattrs are unavailable */
1246 } else if (!(mount_flags & MS_RDONLY)) {
1247 /* If we're read-only it just means that the dir
1248 * hasn't been created. Not an error -- just no
1249 * xattrs on the fs. We'll check again if we
1251 reiserfs_warning(s, "jdm-20006",
1252 "xattrs/ACLs enabled and couldn't "
1253 "find/create .reiserfs_priv. "
1260 #ifdef CONFIG_REISERFS_FS_XATTR
1263 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1264 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1265 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1269 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1270 s->s_flags = s->s_flags & ~MS_POSIXACL;
1271 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1272 if (reiserfs_posixacl(s))
1273 s->s_flags |= MS_POSIXACL;