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>
48 #define FL_READONLY 128
49 #define FL_DIR_SEM_HELD 256
50 #define PRIVROOT_NAME ".reiserfs_priv"
51 #define XAROOT_NAME "xattrs"
53 static struct reiserfs_xattr_handler
*find_xattr_handler_prefix(const char
56 /* Returns the dentry referring to the root of the extended attribute
57 * directory tree. If it has already been retrieved, it is used. If it
58 * hasn't been created and the flags indicate creation is allowed, we
59 * attempt to create it. On error, we return a pointer-encoded error.
61 static struct dentry
*get_xa_root(struct super_block
*sb
, int flags
)
63 struct dentry
*privroot
= dget(REISERFS_SB(sb
)->priv_root
);
64 struct dentry
*xaroot
;
66 /* This needs to be created at mount-time */
68 return ERR_PTR(-ENODATA
);
70 mutex_lock_nested(&privroot
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
71 if (REISERFS_SB(sb
)->xattr_root
) {
72 xaroot
= dget(REISERFS_SB(sb
)->xattr_root
);
76 xaroot
= lookup_one_len(XAROOT_NAME
, privroot
, strlen(XAROOT_NAME
));
79 } else if (!xaroot
->d_inode
) {
81 if (flags
== 0 || flags
& XATTR_CREATE
)
82 err
= privroot
->d_inode
->i_op
->mkdir(privroot
->d_inode
,
86 xaroot
= ERR_PTR(err
);
90 REISERFS_SB(sb
)->xattr_root
= dget(xaroot
);
93 mutex_unlock(&privroot
->d_inode
->i_mutex
);
98 /* Opens the directory corresponding to the inode's extended attribute store.
99 * If flags allow, the tree to the directory may be created. If creation is
100 * prohibited, -ENODATA is returned. */
101 static struct dentry
*open_xa_dir(const struct inode
*inode
, int flags
)
103 struct dentry
*xaroot
, *xadir
;
106 xaroot
= get_xa_root(inode
->i_sb
, flags
);
110 /* ok, we have xaroot open */
111 snprintf(namebuf
, sizeof(namebuf
), "%X.%X",
112 le32_to_cpu(INODE_PKEY(inode
)->k_objectid
),
113 inode
->i_generation
);
114 xadir
= lookup_one_len(namebuf
, xaroot
, strlen(namebuf
));
120 if (!xadir
->d_inode
) {
122 if (flags
== 0 || flags
& XATTR_CREATE
) {
123 /* Although there is nothing else trying to create this directory,
124 * another directory with the same hash may be created, so we need
125 * to protect against that */
127 xaroot
->d_inode
->i_op
->mkdir(xaroot
->d_inode
, xadir
,
135 if (!xadir
->d_inode
) {
138 return ERR_PTR(-ENODATA
);
146 /* Returns a dentry corresponding to a specific extended attribute file
147 * for the inode. If flags allow, the file is created. Otherwise, a
148 * valid or negative dentry, or an error is returned. */
149 static struct dentry
*get_xa_file_dentry(const struct inode
*inode
,
150 const char *name
, int flags
)
152 struct dentry
*xadir
, *xafile
;
155 xadir
= open_xa_dir(inode
, flags
);
157 return ERR_CAST(xadir
);
158 } else if (!xadir
->d_inode
) {
160 return ERR_PTR(-ENODATA
);
163 xafile
= lookup_one_len(name
, xadir
, strlen(name
));
164 if (IS_ERR(xafile
)) {
166 return ERR_CAST(xafile
);
169 if (xafile
->d_inode
) { /* file exists */
170 if (flags
& XATTR_CREATE
) {
175 } else if (flags
& XATTR_REPLACE
|| flags
& FL_READONLY
) {
178 /* inode->i_mutex is down, so nothing else can try to create
180 err
= xadir
->d_inode
->i_op
->create(xadir
->d_inode
, xafile
,
181 0700 | S_IFREG
, NULL
);
192 xafile
= ERR_PTR(err
);
193 else if (!xafile
->d_inode
) {
195 xafile
= ERR_PTR(-ENODATA
);
201 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
202 * we need to drop the path before calling the filldir struct. That
203 * would be a big performance hit to the non-xattr case, so I've copied
204 * the whole thing for now. --clm
206 * the big difference is that I go backwards through the directory,
207 * and don't mess with f->f_pos, but the idea is the same. Do some
208 * action on each and every entry in the directory.
210 * we're called with i_mutex held, so there are no worries about the directory
211 * changing underneath us.
213 static int __xattr_readdir(struct inode
*inode
, void *dirent
, filldir_t filldir
)
215 struct cpu_key pos_key
; /* key of current position in the directory (key of directory entry) */
216 INITIALIZE_PATH(path_to_entry
);
217 struct buffer_head
*bh
;
219 struct item_head
*ih
, tmp_ih
;
223 char small_buf
[32]; /* avoid kmalloc if we can */
224 struct reiserfs_de_head
*deh
;
229 struct reiserfs_dir_entry de
;
231 /* form key for search the next directory entry using f_pos field of
233 next_pos
= max_reiserfs_offset(inode
);
237 if (next_pos
<= DOT_DOT_OFFSET
)
239 make_cpu_key(&pos_key
, inode
, next_pos
, TYPE_DIRENTRY
, 3);
242 search_by_entry_key(inode
->i_sb
, &pos_key
, &path_to_entry
,
244 if (search_res
== IO_ERROR
) {
245 // FIXME: we could just skip part of directory which could
247 pathrelse(&path_to_entry
);
251 if (search_res
== NAME_NOT_FOUND
)
254 set_de_name_and_namelen(&de
);
255 entry_num
= de
.de_entry_num
;
256 deh
= &(de
.de_deh
[entry_num
]);
261 if (!is_direntry_le_ih(ih
)) {
262 reiserfs_error(inode
->i_sb
, "jdm-20000",
263 "not direntry %h", ih
);
266 copy_item_head(&tmp_ih
, ih
);
268 /* we must have found item, that is item of this directory, */
269 RFALSE(COMP_SHORT_KEYS(&(ih
->ih_key
), &pos_key
),
270 "vs-9000: found item %h does not match to dir we readdir %K",
273 if (deh_offset(deh
) <= DOT_DOT_OFFSET
) {
277 /* look for the previous entry in the directory */
278 next_pos
= deh_offset(deh
) - 1;
280 if (!de_visible(deh
))
281 /* it is hidden entry */
284 d_reclen
= entry_length(bh
, ih
, entry_num
);
285 d_name
= B_I_DEH_ENTRY_FILE_NAME(bh
, ih
, deh
);
286 d_off
= deh_offset(deh
);
287 d_ino
= deh_objectid(deh
);
289 if (!d_name
[d_reclen
- 1])
290 d_reclen
= strlen(d_name
);
292 if (d_reclen
> REISERFS_MAX_NAME(inode
->i_sb
->s_blocksize
)) {
293 /* too big to send back to VFS */
297 /* Ignore the .reiserfs_priv entry */
298 if (reiserfs_xattrs(inode
->i_sb
) &&
299 !old_format_only(inode
->i_sb
) &&
301 le32_to_cpu(INODE_PKEY
302 (REISERFS_SB(inode
->i_sb
)->priv_root
->d_inode
)->
306 if (d_reclen
<= 32) {
307 local_buf
= small_buf
;
309 local_buf
= kmalloc(d_reclen
, GFP_NOFS
);
311 pathrelse(&path_to_entry
);
314 if (item_moved(&tmp_ih
, &path_to_entry
)) {
317 /* sigh, must retry. Do this same offset again */
323 // Note, that we copy name to user space via temporary
324 // buffer (local_buf) because filldir will block if
325 // user space buffer is swapped out. At that time
326 // entry can move to somewhere else
327 memcpy(local_buf
, d_name
, d_reclen
);
329 /* the filldir function might need to start transactions,
330 * or do who knows what. Release the path now that we've
331 * copied all the important stuff out of the deh
333 pathrelse(&path_to_entry
);
335 if (filldir(dirent
, local_buf
, d_reclen
, d_off
, d_ino
,
337 if (local_buf
!= small_buf
) {
342 if (local_buf
!= small_buf
) {
348 pathrelse(&path_to_entry
);
353 * this could be done with dedicated readdir ops for the xattr files,
354 * but I want to get something working asap
355 * this is stolen from vfs_readdir
359 int xattr_readdir(struct inode
*inode
, filldir_t filler
, void *buf
)
362 mutex_lock_nested(&inode
->i_mutex
, I_MUTEX_XATTR
);
363 if (!IS_DEADDIR(inode
)) {
365 res
= __xattr_readdir(inode
, buf
, filler
);
368 mutex_unlock(&inode
->i_mutex
);
372 /* Internal operations on file data */
373 static inline void reiserfs_put_page(struct page
*page
)
376 page_cache_release(page
);
379 static struct page
*reiserfs_get_page(struct inode
*dir
, size_t n
)
381 struct address_space
*mapping
= dir
->i_mapping
;
383 /* We can deadlock if we try to free dentries,
384 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
385 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
386 page
= read_mapping_page(mapping
, n
>> PAGE_CACHE_SHIFT
, NULL
);
395 reiserfs_put_page(page
);
396 return ERR_PTR(-EIO
);
399 static inline __u32
xattr_hash(const char *msg
, int len
)
401 return csum_partial(msg
, len
, 0);
404 int reiserfs_commit_write(struct file
*f
, struct page
*page
,
405 unsigned from
, unsigned to
);
406 int reiserfs_prepare_write(struct file
*f
, struct page
*page
,
407 unsigned from
, unsigned to
);
410 /* Generic extended attribute operations that can be used by xa plugins */
413 * inode->i_mutex: down
416 reiserfs_xattr_set(struct inode
*inode
, const char *name
, const void *buffer
,
417 size_t buffer_size
, int flags
)
420 struct dentry
*dentry
;
424 size_t buffer_pos
= 0;
425 struct iattr newattrs
;
428 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
431 /* Empty xattrs are ok, they're just empty files, no hash */
432 if (buffer
&& buffer_size
)
433 xahash
= xattr_hash(buffer
, buffer_size
);
435 dentry
= get_xa_file_dentry(inode
, name
, flags
);
436 if (IS_ERR(dentry
)) {
437 err
= PTR_ERR(dentry
);
441 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
443 /* Resize it so we're ok to write there */
444 newattrs
.ia_size
= buffer_size
;
445 newattrs
.ia_valid
= ATTR_SIZE
| ATTR_CTIME
;
446 mutex_lock_nested(&dentry
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
447 err
= notify_change(dentry
, &newattrs
);
451 while (buffer_pos
< buffer_size
|| buffer_pos
== 0) {
454 size_t page_offset
= (file_pos
& (PAGE_CACHE_SIZE
- 1));
455 if (buffer_size
- buffer_pos
> PAGE_CACHE_SIZE
)
456 chunk
= PAGE_CACHE_SIZE
;
458 chunk
= buffer_size
- buffer_pos
;
460 page
= reiserfs_get_page(dentry
->d_inode
, file_pos
);
467 data
= page_address(page
);
470 struct reiserfs_xattr_header
*rxh
;
471 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
472 if (chunk
+ skip
> PAGE_CACHE_SIZE
)
473 chunk
= PAGE_CACHE_SIZE
- skip
;
474 rxh
= (struct reiserfs_xattr_header
*)data
;
475 rxh
->h_magic
= cpu_to_le32(REISERFS_XATTR_MAGIC
);
476 rxh
->h_hash
= cpu_to_le32(xahash
);
479 err
= reiserfs_prepare_write(NULL
, page
, page_offset
,
480 page_offset
+ chunk
+ skip
);
483 memcpy(data
+ skip
, buffer
+ buffer_pos
, chunk
);
484 err
= reiserfs_commit_write(NULL
, page
, page_offset
,
485 page_offset
+ chunk
+
489 reiserfs_put_page(page
);
493 if (err
|| buffer_size
== 0 || !buffer
)
497 /* We can't mark the inode dirty if it's not hashed. This is the case
498 * when we're inheriting the default ACL. If we dirty it, the inode
499 * gets marked dirty, but won't (ever) make it onto the dirty list until
500 * it's synced explicitly to clear I_DIRTY. This is bad. */
501 if (!hlist_unhashed(&inode
->i_hash
)) {
502 inode
->i_ctime
= CURRENT_TIME_SEC
;
503 mark_inode_dirty(inode
);
507 mutex_unlock(&dentry
->d_inode
->i_mutex
);
515 * inode->i_mutex: down
518 reiserfs_xattr_get(const struct inode
*inode
, const char *name
, void *buffer
,
522 struct dentry
*dentry
;
525 size_t buffer_pos
= 0;
532 /* We can't have xattrs attached to v1 items since they don't have
533 * generation numbers */
534 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
537 dentry
= get_xa_file_dentry(inode
, name
, FL_READONLY
);
538 if (IS_ERR(dentry
)) {
539 err
= PTR_ERR(dentry
);
543 isize
= i_size_read(dentry
->d_inode
);
544 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
546 /* Just return the size needed */
547 if (buffer
== NULL
) {
548 err
= isize
- sizeof(struct reiserfs_xattr_header
);
552 if (buffer_size
< isize
- sizeof(struct reiserfs_xattr_header
)) {
557 while (file_pos
< isize
) {
561 if (isize
- file_pos
> PAGE_CACHE_SIZE
)
562 chunk
= PAGE_CACHE_SIZE
;
564 chunk
= isize
- file_pos
;
566 page
= reiserfs_get_page(dentry
->d_inode
, file_pos
);
573 data
= page_address(page
);
575 struct reiserfs_xattr_header
*rxh
=
576 (struct reiserfs_xattr_header
*)data
;
577 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
579 /* Magic doesn't match up.. */
580 if (rxh
->h_magic
!= cpu_to_le32(REISERFS_XATTR_MAGIC
)) {
582 reiserfs_put_page(page
);
583 reiserfs_warning(inode
->i_sb
, "jdm-20001",
584 "Invalid magic for xattr (%s) "
585 "associated with %k", name
,
590 hash
= le32_to_cpu(rxh
->h_hash
);
592 memcpy(buffer
+ buffer_pos
, data
+ skip
, chunk
);
594 reiserfs_put_page(page
);
599 err
= isize
- sizeof(struct reiserfs_xattr_header
);
601 if (xattr_hash(buffer
, isize
- sizeof(struct reiserfs_xattr_header
)) !=
603 reiserfs_warning(inode
->i_sb
, "jdm-20002",
604 "Invalid hash for xattr (%s) associated "
605 "with %k", name
, INODE_PKEY(inode
));
617 __reiserfs_xattr_del(struct dentry
*xadir
, const char *name
, int namelen
)
619 struct dentry
*dentry
;
620 struct inode
*dir
= xadir
->d_inode
;
623 dentry
= lookup_one_len(name
, xadir
, namelen
);
624 if (IS_ERR(dentry
)) {
625 err
= PTR_ERR(dentry
);
627 } else if (!dentry
->d_inode
) {
632 /* Skip directories.. */
633 if (S_ISDIR(dentry
->d_inode
->i_mode
))
636 if (!is_reiserfs_priv_object(dentry
->d_inode
)) {
637 reiserfs_error(dir
->i_sb
, "jdm-20003",
638 "OID %08x [%.*s/%.*s] doesn't have "
639 "priv flag set [parent is %sset].",
640 le32_to_cpu(INODE_PKEY(dentry
->d_inode
)->
641 k_objectid
), xadir
->d_name
.len
,
642 xadir
->d_name
.name
, namelen
, name
,
643 is_reiserfs_priv_object(xadir
->d_inode
) ? "" :
649 err
= dir
->i_op
->unlink(dir
, dentry
);
660 int reiserfs_xattr_del(struct inode
*inode
, const char *name
)
665 dir
= open_xa_dir(inode
, FL_READONLY
);
671 err
= __reiserfs_xattr_del(dir
, name
, strlen(name
));
675 inode
->i_ctime
= CURRENT_TIME_SEC
;
676 mark_inode_dirty(inode
);
683 /* The following are side effects of other operations that aren't explicitly
684 * modifying extended attributes. This includes operations such as permissions
685 * or ownership changes, object deletions, etc. */
688 reiserfs_delete_xattrs_filler(void *buf
, const char *name
, int namelen
,
689 loff_t offset
, u64 ino
, unsigned int d_type
)
691 struct dentry
*xadir
= (struct dentry
*)buf
;
693 return __reiserfs_xattr_del(xadir
, name
, namelen
);
697 /* This is called w/ inode->i_mutex downed */
698 int reiserfs_delete_xattrs(struct inode
*inode
)
700 struct dentry
*dir
, *root
;
703 /* Skip out, an xattr has no xattrs associated with it */
704 if (is_reiserfs_priv_object(inode
) ||
705 get_inode_sd_version(inode
) == STAT_DATA_V1
||
706 !reiserfs_xattrs(inode
->i_sb
)) {
709 reiserfs_read_lock_xattrs(inode
->i_sb
);
710 dir
= open_xa_dir(inode
, FL_READONLY
);
711 reiserfs_read_unlock_xattrs(inode
->i_sb
);
715 } else if (!dir
->d_inode
) {
721 err
= xattr_readdir(dir
->d_inode
, reiserfs_delete_xattrs_filler
, dir
);
727 /* Leftovers besides . and .. -- that's not good. */
728 if (dir
->d_inode
->i_nlink
<= 2) {
729 root
= get_xa_root(inode
->i_sb
, XATTR_REPLACE
);
730 reiserfs_write_lock_xattrs(inode
->i_sb
);
731 err
= vfs_rmdir(root
->d_inode
, dir
);
732 reiserfs_write_unlock_xattrs(inode
->i_sb
);
735 reiserfs_warning(inode
->i_sb
, "jdm-20006",
736 "Couldn't remove all entries in directory");
745 REISERFS_I(inode
)->i_flags
=
746 REISERFS_I(inode
)->i_flags
& ~i_has_xattr_dir
;
750 struct reiserfs_chown_buf
{
752 struct dentry
*xadir
;
756 /* XXX: If there is a better way to do this, I'd love to hear about it */
758 reiserfs_chown_xattrs_filler(void *buf
, const char *name
, int namelen
,
759 loff_t offset
, u64 ino
, unsigned int d_type
)
761 struct reiserfs_chown_buf
*chown_buf
= (struct reiserfs_chown_buf
*)buf
;
762 struct dentry
*xafile
, *xadir
= chown_buf
->xadir
;
763 struct iattr
*attrs
= chown_buf
->attrs
;
766 xafile
= lookup_one_len(name
, xadir
, namelen
);
768 return PTR_ERR(xafile
);
769 else if (!xafile
->d_inode
) {
774 if (!S_ISDIR(xafile
->d_inode
->i_mode
))
775 err
= notify_change(xafile
, attrs
);
781 int reiserfs_chown_xattrs(struct inode
*inode
, struct iattr
*attrs
)
785 struct reiserfs_chown_buf buf
;
786 unsigned int ia_valid
= attrs
->ia_valid
;
788 /* Skip out, an xattr has no xattrs associated with it */
789 if (is_reiserfs_priv_object(inode
) ||
790 get_inode_sd_version(inode
) == STAT_DATA_V1
||
791 !reiserfs_xattrs(inode
->i_sb
)) {
794 reiserfs_read_lock_xattrs(inode
->i_sb
);
795 dir
= open_xa_dir(inode
, FL_READONLY
);
796 reiserfs_read_unlock_xattrs(inode
->i_sb
);
798 if (PTR_ERR(dir
) != -ENODATA
)
801 } else if (!dir
->d_inode
) {
808 attrs
->ia_valid
&= (ATTR_UID
| ATTR_GID
| ATTR_CTIME
);
813 err
= xattr_readdir(dir
->d_inode
, reiserfs_chown_xattrs_filler
, &buf
);
819 err
= notify_change(dir
, attrs
);
826 attrs
->ia_valid
= ia_valid
;
830 /* Actual operations that are exported to VFS-land */
833 * Inode operation getxattr()
834 * Preliminary locking: we down dentry->d_inode->i_mutex
837 reiserfs_getxattr(struct dentry
* dentry
, const char *name
, void *buffer
,
840 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
843 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
844 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
847 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
848 reiserfs_read_lock_xattrs(dentry
->d_sb
);
849 err
= xah
->get(dentry
->d_inode
, name
, buffer
, size
);
850 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
851 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
856 * Inode operation setxattr()
858 * dentry->d_inode->i_mutex down
861 reiserfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
862 size_t size
, int flags
)
864 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
868 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
869 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
872 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
873 lock
= !has_xattr_dir(dentry
->d_inode
);
875 reiserfs_write_lock_xattrs(dentry
->d_sb
);
877 reiserfs_read_lock_xattrs(dentry
->d_sb
);
878 err
= xah
->set(dentry
->d_inode
, name
, value
, size
, flags
);
880 reiserfs_write_unlock_xattrs(dentry
->d_sb
);
882 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
883 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
888 * Inode operation removexattr()
890 * dentry->d_inode->i_mutex down
892 int reiserfs_removexattr(struct dentry
*dentry
, const char *name
)
895 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
897 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
898 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
901 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
902 reiserfs_read_lock_xattrs(dentry
->d_sb
);
904 /* Deletion pre-operation */
906 err
= xah
->del(dentry
->d_inode
, name
);
911 err
= reiserfs_xattr_del(dentry
->d_inode
, name
);
913 dentry
->d_inode
->i_ctime
= CURRENT_TIME_SEC
;
914 mark_inode_dirty(dentry
->d_inode
);
917 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
918 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
922 /* This is what filldir will use:
923 * r_pos will always contain the amount of space required for the entire
924 * list. If r_pos becomes larger than r_size, we need more space and we
925 * return an error indicating this. If r_pos is less than r_size, then we've
926 * filled the buffer successfully and we return success */
927 struct reiserfs_listxattr_buf
{
931 struct inode
*r_inode
;
935 reiserfs_listxattr_filler(void *buf
, const char *name
, int namelen
,
936 loff_t offset
, u64 ino
, unsigned int d_type
)
938 struct reiserfs_listxattr_buf
*b
= (struct reiserfs_listxattr_buf
*)buf
;
941 || (namelen
!= 1 && (name
[1] != '.' || namelen
!= 2))) {
942 struct reiserfs_xattr_handler
*xah
=
943 find_xattr_handler_prefix(name
);
945 return 0; /* Unsupported xattr name, skip it */
947 /* We call ->list() twice because the operation isn't required to just
948 * return the name back - we want to make sure we have enough space */
949 len
+= xah
->list(b
->r_inode
, name
, namelen
, NULL
);
952 if (b
->r_pos
+ len
+ 1 <= b
->r_size
) {
953 char *p
= b
->r_buf
+ b
->r_pos
;
954 p
+= xah
->list(b
->r_inode
, name
, namelen
, p
);
965 * Inode operation listxattr()
967 * Preliminary locking: we down dentry->d_inode->i_mutex
969 ssize_t
reiserfs_listxattr(struct dentry
* dentry
, char *buffer
, size_t size
)
973 struct reiserfs_listxattr_buf buf
;
975 if (!dentry
->d_inode
)
978 if (!reiserfs_xattrs(dentry
->d_sb
) ||
979 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
982 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
983 reiserfs_read_lock_xattrs(dentry
->d_sb
);
984 dir
= open_xa_dir(dentry
->d_inode
, FL_READONLY
);
985 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
989 err
= 0; /* Not an error if there aren't any xattrs */
994 buf
.r_size
= buffer
? size
: 0;
996 buf
.r_inode
= dentry
->d_inode
;
998 REISERFS_I(dentry
->d_inode
)->i_flags
|= i_has_xattr_dir
;
1000 err
= xattr_readdir(dir
->d_inode
, reiserfs_listxattr_filler
, &buf
);
1004 if (buf
.r_pos
> buf
.r_size
&& buffer
!= NULL
)
1013 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
1017 /* This is the implementation for the xattr plugin infrastructure */
1018 static LIST_HEAD(xattr_handlers
);
1019 static DEFINE_RWLOCK(handler_lock
);
1021 static struct reiserfs_xattr_handler
*find_xattr_handler_prefix(const char
1024 struct reiserfs_xattr_handler
*xah
= NULL
;
1025 struct list_head
*p
;
1027 read_lock(&handler_lock
);
1028 list_for_each(p
, &xattr_handlers
) {
1029 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1030 if (strncmp(xah
->prefix
, prefix
, strlen(xah
->prefix
)) == 0)
1035 read_unlock(&handler_lock
);
1039 static void __unregister_handlers(void)
1041 struct reiserfs_xattr_handler
*xah
;
1042 struct list_head
*p
, *tmp
;
1044 list_for_each_safe(p
, tmp
, &xattr_handlers
) {
1045 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1051 INIT_LIST_HEAD(&xattr_handlers
);
1054 int __init
reiserfs_xattr_register_handlers(void)
1057 struct reiserfs_xattr_handler
*xah
;
1058 struct list_head
*p
;
1060 write_lock(&handler_lock
);
1062 /* If we're already initialized, nothing to do */
1063 if (!list_empty(&xattr_handlers
)) {
1064 write_unlock(&handler_lock
);
1068 /* Add the handlers */
1069 list_add_tail(&user_handler
.handlers
, &xattr_handlers
);
1070 list_add_tail(&trusted_handler
.handlers
, &xattr_handlers
);
1071 #ifdef CONFIG_REISERFS_FS_SECURITY
1072 list_add_tail(&security_handler
.handlers
, &xattr_handlers
);
1074 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1075 list_add_tail(&posix_acl_access_handler
.handlers
, &xattr_handlers
);
1076 list_add_tail(&posix_acl_default_handler
.handlers
, &xattr_handlers
);
1079 /* Run initializers, if available */
1080 list_for_each(p
, &xattr_handlers
) {
1081 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1091 /* Clean up other handlers, if any failed */
1093 __unregister_handlers();
1095 write_unlock(&handler_lock
);
1099 void reiserfs_xattr_unregister_handlers(void)
1101 write_lock(&handler_lock
);
1102 __unregister_handlers();
1103 write_unlock(&handler_lock
);
1106 /* This will catch lookups from the fs root to .reiserfs_priv */
1108 xattr_lookup_poison(struct dentry
*dentry
, struct qstr
*q1
, struct qstr
*name
)
1110 struct dentry
*priv_root
= REISERFS_SB(dentry
->d_sb
)->priv_root
;
1111 if (name
->len
== priv_root
->d_name
.len
&&
1112 name
->hash
== priv_root
->d_name
.hash
&&
1113 !memcmp(name
->name
, priv_root
->d_name
.name
, name
->len
)) {
1115 } else if (q1
->len
== name
->len
&&
1116 !memcmp(q1
->name
, name
->name
, name
->len
))
1121 static struct dentry_operations xattr_lookup_poison_ops
= {
1122 .d_compare
= xattr_lookup_poison
,
1125 /* We need to take a copy of the mount flags since things like
1126 * MS_RDONLY don't get set until *after* we're called.
1127 * mount_flags != mount_options */
1128 int reiserfs_xattr_init(struct super_block
*s
, int mount_flags
)
1132 /* We need generation numbers to ensure that the oid mapping is correct
1133 * v3.5 filesystems don't have them. */
1134 if (!old_format_only(s
)) {
1135 set_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1136 } else if (reiserfs_xattrs_optional(s
)) {
1137 /* Old format filesystem, but optional xattrs have been enabled
1138 * at mount time. Error out. */
1139 reiserfs_warning(s
, "jdm-20005",
1140 "xattrs/ACLs not supported on pre v3.6 "
1141 "format filesystem. Failing mount.");
1145 /* Old format filesystem, but no optional xattrs have been enabled. This
1146 * means we silently disable xattrs on the filesystem. */
1147 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1150 /* If we don't have the privroot located yet - go find it */
1151 if (reiserfs_xattrs(s
) && !REISERFS_SB(s
)->priv_root
) {
1152 struct dentry
*dentry
;
1153 dentry
= lookup_one_len(PRIVROOT_NAME
, s
->s_root
,
1154 strlen(PRIVROOT_NAME
));
1155 if (!IS_ERR(dentry
)) {
1156 if (!(mount_flags
& MS_RDONLY
) && !dentry
->d_inode
) {
1157 struct inode
*inode
= dentry
->d_parent
->d_inode
;
1158 mutex_lock_nested(&inode
->i_mutex
,
1160 err
= inode
->i_op
->mkdir(inode
, dentry
, 0700);
1161 mutex_unlock(&inode
->i_mutex
);
1167 if (dentry
&& dentry
->d_inode
)
1168 reiserfs_info(s
, "Created %s - "
1169 "reserved for xattr "
1172 } else if (!dentry
->d_inode
) {
1177 err
= PTR_ERR(dentry
);
1179 if (!err
&& dentry
) {
1180 s
->s_root
->d_op
= &xattr_lookup_poison_ops
;
1181 reiserfs_mark_inode_private(dentry
->d_inode
);
1182 REISERFS_SB(s
)->priv_root
= dentry
;
1183 } else if (!(mount_flags
& MS_RDONLY
)) { /* xattrs are unavailable */
1184 /* If we're read-only it just means that the dir hasn't been
1185 * created. Not an error -- just no xattrs on the fs. We'll
1186 * check again if we go read-write */
1187 reiserfs_warning(s
, "jdm-20006",
1188 "xattrs/ACLs enabled and couldn't "
1189 "find/create .reiserfs_priv. "
1196 /* This is only nonzero if there was an error initializing the xattr
1197 * directory or if there is a condition where we don't support them. */
1199 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1200 clear_bit(REISERFS_XATTRS_USER
, &(REISERFS_SB(s
)->s_mount_opt
));
1201 clear_bit(REISERFS_POSIXACL
, &(REISERFS_SB(s
)->s_mount_opt
));
1204 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1205 s
->s_flags
= s
->s_flags
& ~MS_POSIXACL
;
1206 if (reiserfs_posixacl(s
))
1207 s
->s_flags
|= MS_POSIXACL
;
1212 static int reiserfs_check_acl(struct inode
*inode
, int mask
)
1214 struct posix_acl
*acl
;
1215 int error
= -EAGAIN
; /* do regular unix permission checks by default */
1217 reiserfs_read_lock_xattr_i(inode
);
1218 reiserfs_read_lock_xattrs(inode
->i_sb
);
1220 acl
= reiserfs_get_acl(inode
, ACL_TYPE_ACCESS
);
1222 reiserfs_read_unlock_xattrs(inode
->i_sb
);
1223 reiserfs_read_unlock_xattr_i(inode
);
1227 error
= posix_acl_permission(inode
, acl
, mask
);
1228 posix_acl_release(acl
);
1229 } else if (PTR_ERR(acl
) != -ENODATA
)
1230 error
= PTR_ERR(acl
);
1236 int reiserfs_permission(struct inode
*inode
, int mask
)
1239 * We don't do permission checks on the internal objects.
1240 * Permissions are determined by the "owning" object.
1242 if (is_reiserfs_priv_object(inode
))
1246 * Stat data v1 doesn't support ACLs.
1248 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
1249 return generic_permission(inode
, mask
, NULL
);
1251 return generic_permission(inode
, mask
, reiserfs_check_acl
);