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 <asm/checksum.h>
45 #include <linux/smp_lock.h>
46 #include <linux/stat.h>
47 #include <asm/semaphore.h>
49 #define FL_READONLY 128
50 #define FL_DIR_SEM_HELD 256
51 #define PRIVROOT_NAME ".reiserfs_priv"
52 #define XAROOT_NAME "xattrs"
54 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
57 static struct dentry *create_xa_root(struct super_block *sb)
59 struct dentry *privroot = dget(REISERFS_SB(sb)->priv_root);
60 struct dentry *xaroot;
62 /* This needs to be created at mount-time */
64 return ERR_PTR(-EOPNOTSUPP);
66 xaroot = lookup_one_len(XAROOT_NAME, privroot, strlen(XAROOT_NAME));
69 } else if (!xaroot->d_inode) {
71 mutex_lock(&privroot->d_inode->i_mutex);
73 privroot->d_inode->i_op->mkdir(privroot->d_inode, xaroot,
75 mutex_unlock(&privroot->d_inode->i_mutex);
82 REISERFS_SB(sb)->xattr_root = dget(xaroot);
90 /* This will return a dentry, or error, refering to the xa root directory.
91 * If the xa root doesn't exist yet, the dentry will be returned without
92 * an associated inode. This dentry can be used with ->mkdir to create
93 * the xa directory. */
94 static struct dentry *__get_xa_root(struct super_block *s)
96 struct dentry *privroot = dget(REISERFS_SB(s)->priv_root);
97 struct dentry *xaroot = NULL;
99 if (IS_ERR(privroot) || !privroot)
102 xaroot = lookup_one_len(XAROOT_NAME, privroot, strlen(XAROOT_NAME));
103 if (IS_ERR(xaroot)) {
105 } else if (!xaroot->d_inode) {
111 REISERFS_SB(s)->xattr_root = dget(xaroot);
118 /* Returns the dentry (or NULL) referring to the root of the extended
119 * attribute directory tree. If it has already been retrieved, it is used.
120 * Otherwise, we attempt to retrieve it from disk. It may also return
121 * a pointer-encoded error.
123 static inline struct dentry *get_xa_root(struct super_block *s)
125 struct dentry *dentry = dget(REISERFS_SB(s)->xattr_root);
128 dentry = __get_xa_root(s);
133 /* Opens the directory corresponding to the inode's extended attribute store.
134 * If flags allow, the tree to the directory may be created. If creation is
135 * prohibited, -ENODATA is returned. */
136 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
138 struct dentry *xaroot, *xadir;
141 xaroot = get_xa_root(inode->i_sb);
142 if (IS_ERR(xaroot)) {
144 } else if (!xaroot) {
145 if (flags == 0 || flags & XATTR_CREATE) {
146 xaroot = create_xa_root(inode->i_sb);
151 return ERR_PTR(-ENODATA);
154 /* ok, we have xaroot open */
156 snprintf(namebuf, sizeof(namebuf), "%X.%X",
157 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
158 inode->i_generation);
159 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
165 if (!xadir->d_inode) {
167 if (flags == 0 || flags & XATTR_CREATE) {
168 /* Although there is nothing else trying to create this directory,
169 * another directory with the same hash may be created, so we need
170 * to protect against that */
172 xaroot->d_inode->i_op->mkdir(xaroot->d_inode, xadir,
180 if (!xadir->d_inode) {
183 return ERR_PTR(-ENODATA);
191 /* Returns a dentry corresponding to a specific extended attribute file
192 * for the inode. If flags allow, the file is created. Otherwise, a
193 * valid or negative dentry, or an error is returned. */
194 static struct dentry *get_xa_file_dentry(const struct inode *inode,
195 const char *name, int flags)
197 struct dentry *xadir, *xafile;
200 xadir = open_xa_dir(inode, flags);
202 return ERR_PTR(PTR_ERR(xadir));
203 } else if (xadir && !xadir->d_inode) {
205 return ERR_PTR(-ENODATA);
208 xafile = lookup_one_len(name, xadir, strlen(name));
209 if (IS_ERR(xafile)) {
211 return ERR_PTR(PTR_ERR(xafile));
214 if (xafile->d_inode) { /* file exists */
215 if (flags & XATTR_CREATE) {
220 } else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
223 /* inode->i_mutex is down, so nothing else can try to create
225 err = xadir->d_inode->i_op->create(xadir->d_inode, xafile,
226 0700 | S_IFREG, NULL);
237 xafile = ERR_PTR(err);
241 /* Opens a file pointer to the attribute associated with inode */
242 static struct file *open_xa_file(const struct inode *inode, const char *name,
245 struct dentry *xafile;
248 xafile = get_xa_file_dentry(inode, name, flags);
250 return ERR_PTR(PTR_ERR(xafile));
251 else if (!xafile->d_inode) {
253 return ERR_PTR(-ENODATA);
256 fp = dentry_open(xafile, NULL, O_RDWR);
257 /* dentry_open dputs the dentry if it fails */
263 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
264 * we need to drop the path before calling the filldir struct. That
265 * would be a big performance hit to the non-xattr case, so I've copied
266 * the whole thing for now. --clm
268 * the big difference is that I go backwards through the directory,
269 * and don't mess with f->f_pos, but the idea is the same. Do some
270 * action on each and every entry in the directory.
272 * we're called with i_mutex held, so there are no worries about the directory
273 * changing underneath us.
275 static int __xattr_readdir(struct file *filp, void *dirent, filldir_t filldir)
277 struct inode *inode = filp->f_dentry->d_inode;
278 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
279 INITIALIZE_PATH(path_to_entry);
280 struct buffer_head *bh;
282 struct item_head *ih, tmp_ih;
286 char small_buf[32]; /* avoid kmalloc if we can */
287 struct reiserfs_de_head *deh;
292 struct reiserfs_dir_entry de;
294 /* form key for search the next directory entry using f_pos field of
296 next_pos = max_reiserfs_offset(inode);
300 if (next_pos <= DOT_DOT_OFFSET)
302 make_cpu_key(&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
305 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
307 if (search_res == IO_ERROR) {
308 // FIXME: we could just skip part of directory which could
310 pathrelse(&path_to_entry);
314 if (search_res == NAME_NOT_FOUND)
317 set_de_name_and_namelen(&de);
318 entry_num = de.de_entry_num;
319 deh = &(de.de_deh[entry_num]);
324 if (!is_direntry_le_ih(ih)) {
325 reiserfs_warning(inode->i_sb, "not direntry %h", ih);
328 copy_item_head(&tmp_ih, ih);
330 /* we must have found item, that is item of this directory, */
331 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
332 "vs-9000: found item %h does not match to dir we readdir %K",
335 if (deh_offset(deh) <= DOT_DOT_OFFSET) {
339 /* look for the previous entry in the directory */
340 next_pos = deh_offset(deh) - 1;
342 if (!de_visible(deh))
343 /* it is hidden entry */
346 d_reclen = entry_length(bh, ih, entry_num);
347 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
348 d_off = deh_offset(deh);
349 d_ino = deh_objectid(deh);
351 if (!d_name[d_reclen - 1])
352 d_reclen = strlen(d_name);
354 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)) {
355 /* too big to send back to VFS */
359 /* Ignore the .reiserfs_priv entry */
360 if (reiserfs_xattrs(inode->i_sb) &&
361 !old_format_only(inode->i_sb) &&
363 le32_to_cpu(INODE_PKEY
364 (REISERFS_SB(inode->i_sb)->priv_root->d_inode)->
368 if (d_reclen <= 32) {
369 local_buf = small_buf;
372 reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb);
374 pathrelse(&path_to_entry);
377 if (item_moved(&tmp_ih, &path_to_entry)) {
378 reiserfs_kfree(local_buf, d_reclen,
381 /* sigh, must retry. Do this same offset again */
387 // Note, that we copy name to user space via temporary
388 // buffer (local_buf) because filldir will block if
389 // user space buffer is swapped out. At that time
390 // entry can move to somewhere else
391 memcpy(local_buf, d_name, d_reclen);
393 /* the filldir function might need to start transactions,
394 * or do who knows what. Release the path now that we've
395 * copied all the important stuff out of the deh
397 pathrelse(&path_to_entry);
399 if (filldir(dirent, local_buf, d_reclen, d_off, d_ino,
401 if (local_buf != small_buf) {
402 reiserfs_kfree(local_buf, d_reclen,
407 if (local_buf != small_buf) {
408 reiserfs_kfree(local_buf, d_reclen, inode->i_sb);
413 pathrelse(&path_to_entry);
418 * this could be done with dedicated readdir ops for the xattr files,
419 * but I want to get something working asap
420 * this is stolen from vfs_readdir
424 int xattr_readdir(struct file *file, filldir_t filler, void *buf)
426 struct inode *inode = file->f_dentry->d_inode;
428 if (!file->f_op || !file->f_op->readdir)
430 mutex_lock(&inode->i_mutex);
431 // down(&inode->i_zombie);
433 if (!IS_DEADDIR(inode)) {
435 res = __xattr_readdir(file, buf, filler);
438 // up(&inode->i_zombie);
439 mutex_unlock(&inode->i_mutex);
444 /* Internal operations on file data */
445 static inline void reiserfs_put_page(struct page *page)
448 page_cache_release(page);
451 static struct page *reiserfs_get_page(struct inode *dir, unsigned long n)
453 struct address_space *mapping = dir->i_mapping;
455 /* We can deadlock if we try to free dentries,
456 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
457 mapping_set_gfp_mask(mapping, GFP_NOFS);
458 page = read_cache_page(mapping, n,
459 (filler_t *) mapping->a_ops->readpage, NULL);
461 wait_on_page_locked(page);
463 if (!PageUptodate(page))
472 reiserfs_put_page(page);
473 return ERR_PTR(-EIO);
476 static inline __u32 xattr_hash(const char *msg, int len)
478 return csum_partial(msg, len, 0);
481 /* Generic extended attribute operations that can be used by xa plugins */
484 * inode->i_mutex: down
487 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
488 size_t buffer_size, int flags)
494 struct address_space *mapping;
496 size_t buffer_pos = 0;
497 struct inode *xinode;
498 struct iattr newattrs;
501 if (get_inode_sd_version(inode) == STAT_DATA_V1)
504 /* Empty xattrs are ok, they're just empty files, no hash */
505 if (buffer && buffer_size)
506 xahash = xattr_hash(buffer, buffer_size);
509 fp = open_xa_file(inode, name, flags);
515 xinode = fp->f_dentry->d_inode;
516 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
518 /* we need to copy it off.. */
519 if (xinode->i_nlink > 1) {
521 err = reiserfs_xattr_del(inode, name);
524 /* We just killed the old one, we're not replacing anymore */
525 if (flags & XATTR_REPLACE)
526 flags &= ~XATTR_REPLACE;
530 /* Resize it so we're ok to write there */
531 newattrs.ia_size = buffer_size;
532 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
533 mutex_lock(&xinode->i_mutex);
534 err = notify_change(fp->f_dentry, &newattrs);
538 mapping = xinode->i_mapping;
539 while (buffer_pos < buffer_size || buffer_pos == 0) {
542 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
543 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
544 chunk = PAGE_CACHE_SIZE;
546 chunk = buffer_size - buffer_pos;
548 page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
555 data = page_address(page);
558 struct reiserfs_xattr_header *rxh;
559 skip = file_pos = sizeof(struct reiserfs_xattr_header);
560 if (chunk + skip > PAGE_CACHE_SIZE)
561 chunk = PAGE_CACHE_SIZE - skip;
562 rxh = (struct reiserfs_xattr_header *)data;
563 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
564 rxh->h_hash = cpu_to_le32(xahash);
567 err = mapping->a_ops->prepare_write(fp, page, page_offset,
568 page_offset + chunk + skip);
571 memcpy(data + skip, buffer + buffer_pos, chunk);
573 mapping->a_ops->commit_write(fp, page, page_offset,
574 page_offset + chunk +
578 reiserfs_put_page(page);
582 if (err || buffer_size == 0 || !buffer)
586 /* We can't mark the inode dirty if it's not hashed. This is the case
587 * when we're inheriting the default ACL. If we dirty it, the inode
588 * gets marked dirty, but won't (ever) make it onto the dirty list until
589 * it's synced explicitly to clear I_DIRTY. This is bad. */
590 if (!hlist_unhashed(&inode->i_hash)) {
591 inode->i_ctime = CURRENT_TIME_SEC;
592 mark_inode_dirty(inode);
596 mutex_unlock(&xinode->i_mutex);
604 * inode->i_mutex: down
607 reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
614 size_t buffer_pos = 0;
616 struct inode *xinode;
622 /* We can't have xattrs attached to v1 items since they don't have
623 * generation numbers */
624 if (get_inode_sd_version(inode) == STAT_DATA_V1)
627 fp = open_xa_file(inode, name, FL_READONLY);
633 xinode = fp->f_dentry->d_inode;
634 isize = xinode->i_size;
635 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
637 /* Just return the size needed */
638 if (buffer == NULL) {
639 err = isize - sizeof(struct reiserfs_xattr_header);
643 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
648 while (file_pos < isize) {
652 if (isize - file_pos > PAGE_CACHE_SIZE)
653 chunk = PAGE_CACHE_SIZE;
655 chunk = isize - file_pos;
657 page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
664 data = page_address(page);
666 struct reiserfs_xattr_header *rxh =
667 (struct reiserfs_xattr_header *)data;
668 skip = file_pos = sizeof(struct reiserfs_xattr_header);
670 /* Magic doesn't match up.. */
671 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
673 reiserfs_put_page(page);
674 reiserfs_warning(inode->i_sb,
675 "Invalid magic for xattr (%s) "
676 "associated with %k", name,
681 hash = le32_to_cpu(rxh->h_hash);
683 memcpy(buffer + buffer_pos, data + skip, chunk);
685 reiserfs_put_page(page);
690 err = isize - sizeof(struct reiserfs_xattr_header);
692 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
694 reiserfs_warning(inode->i_sb,
695 "Invalid hash for xattr (%s) associated "
696 "with %k", name, INODE_PKEY(inode));
708 __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
710 struct dentry *dentry;
711 struct inode *dir = xadir->d_inode;
714 dentry = lookup_one_len(name, xadir, namelen);
715 if (IS_ERR(dentry)) {
716 err = PTR_ERR(dentry);
718 } else if (!dentry->d_inode) {
723 /* Skip directories.. */
724 if (S_ISDIR(dentry->d_inode->i_mode))
727 if (!is_reiserfs_priv_object(dentry->d_inode)) {
728 reiserfs_warning(dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
729 "priv flag set [parent is %sset].",
730 le32_to_cpu(INODE_PKEY(dentry->d_inode)->
731 k_objectid), xadir->d_name.len,
732 xadir->d_name.name, namelen, name,
733 is_reiserfs_priv_object(xadir->
740 err = dir->i_op->unlink(dir, dentry);
751 int reiserfs_xattr_del(struct inode *inode, const char *name)
756 dir = open_xa_dir(inode, FL_READONLY);
762 err = __reiserfs_xattr_del(dir, name, strlen(name));
766 inode->i_ctime = CURRENT_TIME_SEC;
767 mark_inode_dirty(inode);
774 /* The following are side effects of other operations that aren't explicitly
775 * modifying extended attributes. This includes operations such as permissions
776 * or ownership changes, object deletions, etc. */
779 reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
780 loff_t offset, ino_t ino, unsigned int d_type)
782 struct dentry *xadir = (struct dentry *)buf;
784 return __reiserfs_xattr_del(xadir, name, namelen);
788 /* This is called w/ inode->i_mutex downed */
789 int reiserfs_delete_xattrs(struct inode *inode)
792 struct dentry *dir, *root;
795 /* Skip out, an xattr has no xattrs associated with it */
796 if (is_reiserfs_priv_object(inode) ||
797 get_inode_sd_version(inode) == STAT_DATA_V1 ||
798 !reiserfs_xattrs(inode->i_sb)) {
801 reiserfs_read_lock_xattrs(inode->i_sb);
802 dir = open_xa_dir(inode, FL_READONLY);
803 reiserfs_read_unlock_xattrs(inode->i_sb);
807 } else if (!dir->d_inode) {
812 fp = dentry_open(dir, NULL, O_RDWR);
815 /* dentry_open dputs the dentry if it fails */
820 err = xattr_readdir(fp, reiserfs_delete_xattrs_filler, dir);
826 /* Leftovers besides . and .. -- that's not good. */
827 if (dir->d_inode->i_nlink <= 2) {
828 root = get_xa_root(inode->i_sb);
829 reiserfs_write_lock_xattrs(inode->i_sb);
830 err = vfs_rmdir(root->d_inode, dir);
831 reiserfs_write_unlock_xattrs(inode->i_sb);
834 reiserfs_warning(inode->i_sb,
835 "Couldn't remove all entries in directory");
844 REISERFS_I(inode)->i_flags =
845 REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
849 struct reiserfs_chown_buf {
851 struct dentry *xadir;
855 /* XXX: If there is a better way to do this, I'd love to hear about it */
857 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
858 loff_t offset, ino_t ino, unsigned int d_type)
860 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
861 struct dentry *xafile, *xadir = chown_buf->xadir;
862 struct iattr *attrs = chown_buf->attrs;
865 xafile = lookup_one_len(name, xadir, namelen);
867 return PTR_ERR(xafile);
868 else if (!xafile->d_inode) {
873 if (!S_ISDIR(xafile->d_inode->i_mode))
874 err = notify_change(xafile, attrs);
880 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
885 struct reiserfs_chown_buf buf;
886 unsigned int ia_valid = attrs->ia_valid;
888 /* Skip out, an xattr has no xattrs associated with it */
889 if (is_reiserfs_priv_object(inode) ||
890 get_inode_sd_version(inode) == STAT_DATA_V1 ||
891 !reiserfs_xattrs(inode->i_sb)) {
894 reiserfs_read_lock_xattrs(inode->i_sb);
895 dir = open_xa_dir(inode, FL_READONLY);
896 reiserfs_read_unlock_xattrs(inode->i_sb);
898 if (PTR_ERR(dir) != -ENODATA)
901 } else if (!dir->d_inode) {
906 fp = dentry_open(dir, NULL, O_RDWR);
909 /* dentry_open dputs the dentry if it fails */
915 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
920 err = xattr_readdir(fp, reiserfs_chown_xattrs_filler, &buf);
926 err = notify_change(dir, attrs);
933 attrs->ia_valid = ia_valid;
937 /* Actual operations that are exported to VFS-land */
940 * Inode operation getxattr()
941 * Preliminary locking: we down dentry->d_inode->i_mutex
944 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
947 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
950 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
951 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
954 reiserfs_read_lock_xattr_i(dentry->d_inode);
955 reiserfs_read_lock_xattrs(dentry->d_sb);
956 err = xah->get(dentry->d_inode, name, buffer, size);
957 reiserfs_read_unlock_xattrs(dentry->d_sb);
958 reiserfs_read_unlock_xattr_i(dentry->d_inode);
963 * Inode operation setxattr()
965 * dentry->d_inode->i_mutex down
968 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
969 size_t size, int flags)
971 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
975 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
976 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
979 reiserfs_write_lock_xattr_i(dentry->d_inode);
980 lock = !has_xattr_dir(dentry->d_inode);
982 reiserfs_write_lock_xattrs(dentry->d_sb);
984 reiserfs_read_lock_xattrs(dentry->d_sb);
985 err = xah->set(dentry->d_inode, name, value, size, flags);
987 reiserfs_write_unlock_xattrs(dentry->d_sb);
989 reiserfs_read_unlock_xattrs(dentry->d_sb);
990 reiserfs_write_unlock_xattr_i(dentry->d_inode);
995 * Inode operation removexattr()
997 * dentry->d_inode->i_mutex down
999 int reiserfs_removexattr(struct dentry *dentry, const char *name)
1002 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
1004 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
1005 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
1008 reiserfs_write_lock_xattr_i(dentry->d_inode);
1009 reiserfs_read_lock_xattrs(dentry->d_sb);
1011 /* Deletion pre-operation */
1013 err = xah->del(dentry->d_inode, name);
1018 err = reiserfs_xattr_del(dentry->d_inode, name);
1020 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
1021 mark_inode_dirty(dentry->d_inode);
1024 reiserfs_read_unlock_xattrs(dentry->d_sb);
1025 reiserfs_write_unlock_xattr_i(dentry->d_inode);
1029 /* This is what filldir will use:
1030 * r_pos will always contain the amount of space required for the entire
1031 * list. If r_pos becomes larger than r_size, we need more space and we
1032 * return an error indicating this. If r_pos is less than r_size, then we've
1033 * filled the buffer successfully and we return success */
1034 struct reiserfs_listxattr_buf {
1038 struct inode *r_inode;
1042 reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
1043 loff_t offset, ino_t ino, unsigned int d_type)
1045 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
1048 || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
1049 struct reiserfs_xattr_handler *xah =
1050 find_xattr_handler_prefix(name);
1052 return 0; /* Unsupported xattr name, skip it */
1054 /* We call ->list() twice because the operation isn't required to just
1055 * return the name back - we want to make sure we have enough space */
1056 len += xah->list(b->r_inode, name, namelen, NULL);
1059 if (b->r_pos + len + 1 <= b->r_size) {
1060 char *p = b->r_buf + b->r_pos;
1061 p += xah->list(b->r_inode, name, namelen, p);
1064 b->r_pos += len + 1;
1072 * Inode operation listxattr()
1074 * Preliminary locking: we down dentry->d_inode->i_mutex
1076 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
1081 struct reiserfs_listxattr_buf buf;
1083 if (!dentry->d_inode)
1086 if (!reiserfs_xattrs(dentry->d_sb) ||
1087 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
1090 reiserfs_read_lock_xattr_i(dentry->d_inode);
1091 reiserfs_read_lock_xattrs(dentry->d_sb);
1092 dir = open_xa_dir(dentry->d_inode, FL_READONLY);
1093 reiserfs_read_unlock_xattrs(dentry->d_sb);
1096 if (err == -ENODATA)
1097 err = 0; /* Not an error if there aren't any xattrs */
1101 fp = dentry_open(dir, NULL, O_RDWR);
1104 /* dentry_open dputs the dentry if it fails */
1109 buf.r_size = buffer ? size : 0;
1111 buf.r_inode = dentry->d_inode;
1113 REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
1115 err = xattr_readdir(fp, reiserfs_listxattr_filler, &buf);
1119 if (buf.r_pos > buf.r_size && buffer != NULL)
1128 reiserfs_read_unlock_xattr_i(dentry->d_inode);
1132 /* This is the implementation for the xattr plugin infrastructure */
1133 static struct list_head xattr_handlers = LIST_HEAD_INIT(xattr_handlers);
1134 static DEFINE_RWLOCK(handler_lock);
1136 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
1139 struct reiserfs_xattr_handler *xah = NULL;
1140 struct list_head *p;
1142 read_lock(&handler_lock);
1143 list_for_each(p, &xattr_handlers) {
1144 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1145 if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
1150 read_unlock(&handler_lock);
1154 static void __unregister_handlers(void)
1156 struct reiserfs_xattr_handler *xah;
1157 struct list_head *p, *tmp;
1159 list_for_each_safe(p, tmp, &xattr_handlers) {
1160 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1166 INIT_LIST_HEAD(&xattr_handlers);
1169 int __init reiserfs_xattr_register_handlers(void)
1172 struct reiserfs_xattr_handler *xah;
1173 struct list_head *p;
1175 write_lock(&handler_lock);
1177 /* If we're already initialized, nothing to do */
1178 if (!list_empty(&xattr_handlers)) {
1179 write_unlock(&handler_lock);
1183 /* Add the handlers */
1184 list_add_tail(&user_handler.handlers, &xattr_handlers);
1185 list_add_tail(&trusted_handler.handlers, &xattr_handlers);
1186 #ifdef CONFIG_REISERFS_FS_SECURITY
1187 list_add_tail(&security_handler.handlers, &xattr_handlers);
1189 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1190 list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
1191 list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
1194 /* Run initializers, if available */
1195 list_for_each(p, &xattr_handlers) {
1196 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1206 /* Clean up other handlers, if any failed */
1208 __unregister_handlers();
1210 write_unlock(&handler_lock);
1214 void reiserfs_xattr_unregister_handlers(void)
1216 write_lock(&handler_lock);
1217 __unregister_handlers();
1218 write_unlock(&handler_lock);
1221 /* This will catch lookups from the fs root to .reiserfs_priv */
1223 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1225 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1226 if (name->len == priv_root->d_name.len &&
1227 name->hash == priv_root->d_name.hash &&
1228 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1230 } else if (q1->len == name->len &&
1231 !memcmp(q1->name, name->name, name->len))
1236 static struct dentry_operations xattr_lookup_poison_ops = {
1237 .d_compare = xattr_lookup_poison,
1240 /* We need to take a copy of the mount flags since things like
1241 * MS_RDONLY don't get set until *after* we're called.
1242 * mount_flags != mount_options */
1243 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1247 /* We need generation numbers to ensure that the oid mapping is correct
1248 * v3.5 filesystems don't have them. */
1249 if (!old_format_only(s)) {
1250 set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1251 } else if (reiserfs_xattrs_optional(s)) {
1252 /* Old format filesystem, but optional xattrs have been enabled
1253 * at mount time. Error out. */
1254 reiserfs_warning(s, "xattrs/ACLs not supported on pre v3.6 "
1255 "format filesystem. Failing mount.");
1259 /* Old format filesystem, but no optional xattrs have been enabled. This
1260 * means we silently disable xattrs on the filesystem. */
1261 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1264 /* If we don't have the privroot located yet - go find it */
1265 if (reiserfs_xattrs(s) && !REISERFS_SB(s)->priv_root) {
1266 struct dentry *dentry;
1267 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1268 strlen(PRIVROOT_NAME));
1269 if (!IS_ERR(dentry)) {
1270 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
1271 struct inode *inode = dentry->d_parent->d_inode;
1272 mutex_lock(&inode->i_mutex);
1273 err = inode->i_op->mkdir(inode, dentry, 0700);
1274 mutex_unlock(&inode->i_mutex);
1280 if (dentry && dentry->d_inode)
1282 "Created %s on %s - reserved for "
1287 } else if (!dentry->d_inode) {
1292 err = PTR_ERR(dentry);
1294 if (!err && dentry) {
1295 s->s_root->d_op = &xattr_lookup_poison_ops;
1296 reiserfs_mark_inode_private(dentry->d_inode);
1297 REISERFS_SB(s)->priv_root = dentry;
1298 } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
1299 /* If we're read-only it just means that the dir hasn't been
1300 * created. Not an error -- just no xattrs on the fs. We'll
1301 * check again if we go read-write */
1302 reiserfs_warning(s, "xattrs/ACLs enabled and couldn't "
1303 "find/create .reiserfs_priv. Failing mount.");
1309 /* This is only nonzero if there was an error initializing the xattr
1310 * directory or if there is a condition where we don't support them. */
1312 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1313 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1314 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1317 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1318 s->s_flags = s->s_flags & ~MS_POSIXACL;
1319 if (reiserfs_posixacl(s))
1320 s->s_flags |= MS_POSIXACL;
1326 __reiserfs_permission(struct inode *inode, int mask, struct nameidata *nd,
1329 umode_t mode = inode->i_mode;
1331 if (mask & MAY_WRITE) {
1333 * Nobody gets write access to a read-only fs.
1335 if (IS_RDONLY(inode) &&
1336 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
1340 * Nobody gets write access to an immutable file.
1342 if (IS_IMMUTABLE(inode))
1346 /* We don't do permission checks on the internal objects.
1347 * Permissions are determined by the "owning" object. */
1348 if (is_reiserfs_priv_object(inode))
1351 if (current->fsuid == inode->i_uid) {
1353 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1354 } else if (reiserfs_posixacl(inode->i_sb) &&
1355 get_inode_sd_version(inode) != STAT_DATA_V1) {
1356 struct posix_acl *acl;
1358 /* ACL can't contain additional permissions if
1359 the ACL_MASK entry is 0 */
1360 if (!(mode & S_IRWXG))
1364 reiserfs_read_lock_xattr_i(inode);
1365 reiserfs_read_lock_xattrs(inode->i_sb);
1367 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1369 reiserfs_read_unlock_xattrs(inode->i_sb);
1370 reiserfs_read_unlock_xattr_i(inode);
1373 if (PTR_ERR(acl) == -ENODATA)
1375 return PTR_ERR(acl);
1379 int err = posix_acl_permission(inode, acl, mask);
1380 posix_acl_release(acl);
1381 if (err == -EACCES) {
1382 goto check_capabilities;
1391 if (in_group_p(inode->i_gid))
1396 * If the DACs are ok we don't need any capability check.
1398 if (((mode & mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == mask))
1403 * Read/write DACs are always overridable.
1404 * Executable DACs are overridable if at least one exec bit is set.
1406 if (!(mask & MAY_EXEC) ||
1407 (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
1408 if (capable(CAP_DAC_OVERRIDE))
1412 * Searching includes executable on directories, else just read.
1414 if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
1415 if (capable(CAP_DAC_READ_SEARCH))
1421 int reiserfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1423 return __reiserfs_permission(inode, mask, nd, 1);
1427 reiserfs_permission_locked(struct inode *inode, int mask, struct nameidata *nd)
1429 return __reiserfs_permission(inode, mask, nd, 0);