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
, unsigned long 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
, 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
);
436 dentry
= get_xa_file_dentry(inode
, name
, flags
);
437 if (IS_ERR(dentry
)) {
438 err
= PTR_ERR(dentry
);
442 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
444 /* we need to copy it off.. */
445 if (dentry
->d_inode
->i_nlink
> 1) {
447 err
= reiserfs_xattr_del(inode
, name
);
450 /* We just killed the old one, we're not replacing anymore */
451 if (flags
& XATTR_REPLACE
)
452 flags
&= ~XATTR_REPLACE
;
456 /* Resize it so we're ok to write there */
457 newattrs
.ia_size
= buffer_size
;
458 newattrs
.ia_valid
= ATTR_SIZE
| ATTR_CTIME
;
459 mutex_lock_nested(&dentry
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
460 err
= notify_change(dentry
, &newattrs
);
464 while (buffer_pos
< buffer_size
|| buffer_pos
== 0) {
467 size_t page_offset
= (file_pos
& (PAGE_CACHE_SIZE
- 1));
468 if (buffer_size
- buffer_pos
> PAGE_CACHE_SIZE
)
469 chunk
= PAGE_CACHE_SIZE
;
471 chunk
= buffer_size
- buffer_pos
;
473 page
= reiserfs_get_page(dentry
->d_inode
,
474 file_pos
>> PAGE_CACHE_SHIFT
);
481 data
= page_address(page
);
484 struct reiserfs_xattr_header
*rxh
;
485 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
486 if (chunk
+ skip
> PAGE_CACHE_SIZE
)
487 chunk
= PAGE_CACHE_SIZE
- skip
;
488 rxh
= (struct reiserfs_xattr_header
*)data
;
489 rxh
->h_magic
= cpu_to_le32(REISERFS_XATTR_MAGIC
);
490 rxh
->h_hash
= cpu_to_le32(xahash
);
493 err
= reiserfs_prepare_write(NULL
, page
, page_offset
,
494 page_offset
+ chunk
+ skip
);
497 memcpy(data
+ skip
, buffer
+ buffer_pos
, chunk
);
498 err
= reiserfs_commit_write(NULL
, page
, page_offset
,
499 page_offset
+ chunk
+
503 reiserfs_put_page(page
);
507 if (err
|| buffer_size
== 0 || !buffer
)
511 /* We can't mark the inode dirty if it's not hashed. This is the case
512 * when we're inheriting the default ACL. If we dirty it, the inode
513 * gets marked dirty, but won't (ever) make it onto the dirty list until
514 * it's synced explicitly to clear I_DIRTY. This is bad. */
515 if (!hlist_unhashed(&inode
->i_hash
)) {
516 inode
->i_ctime
= CURRENT_TIME_SEC
;
517 mark_inode_dirty(inode
);
521 mutex_unlock(&dentry
->d_inode
->i_mutex
);
529 * inode->i_mutex: down
532 reiserfs_xattr_get(const struct inode
*inode
, const char *name
, void *buffer
,
536 struct dentry
*dentry
;
539 size_t buffer_pos
= 0;
546 /* We can't have xattrs attached to v1 items since they don't have
547 * generation numbers */
548 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
551 dentry
= get_xa_file_dentry(inode
, name
, FL_READONLY
);
552 if (IS_ERR(dentry
)) {
553 err
= PTR_ERR(dentry
);
557 isize
= i_size_read(dentry
->d_inode
);
558 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
560 /* Just return the size needed */
561 if (buffer
== NULL
) {
562 err
= isize
- sizeof(struct reiserfs_xattr_header
);
566 if (buffer_size
< isize
- sizeof(struct reiserfs_xattr_header
)) {
571 while (file_pos
< isize
) {
575 if (isize
- file_pos
> PAGE_CACHE_SIZE
)
576 chunk
= PAGE_CACHE_SIZE
;
578 chunk
= isize
- file_pos
;
580 page
= reiserfs_get_page(dentry
->d_inode
,
581 file_pos
>> PAGE_CACHE_SHIFT
);
588 data
= page_address(page
);
590 struct reiserfs_xattr_header
*rxh
=
591 (struct reiserfs_xattr_header
*)data
;
592 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
594 /* Magic doesn't match up.. */
595 if (rxh
->h_magic
!= cpu_to_le32(REISERFS_XATTR_MAGIC
)) {
597 reiserfs_put_page(page
);
598 reiserfs_warning(inode
->i_sb
, "jdm-20001",
599 "Invalid magic for xattr (%s) "
600 "associated with %k", name
,
605 hash
= le32_to_cpu(rxh
->h_hash
);
607 memcpy(buffer
+ buffer_pos
, data
+ skip
, chunk
);
609 reiserfs_put_page(page
);
614 err
= isize
- sizeof(struct reiserfs_xattr_header
);
616 if (xattr_hash(buffer
, isize
- sizeof(struct reiserfs_xattr_header
)) !=
618 reiserfs_warning(inode
->i_sb
, "jdm-20002",
619 "Invalid hash for xattr (%s) associated "
620 "with %k", name
, INODE_PKEY(inode
));
632 __reiserfs_xattr_del(struct dentry
*xadir
, const char *name
, int namelen
)
634 struct dentry
*dentry
;
635 struct inode
*dir
= xadir
->d_inode
;
638 dentry
= lookup_one_len(name
, xadir
, namelen
);
639 if (IS_ERR(dentry
)) {
640 err
= PTR_ERR(dentry
);
642 } else if (!dentry
->d_inode
) {
647 /* Skip directories.. */
648 if (S_ISDIR(dentry
->d_inode
->i_mode
))
651 if (!is_reiserfs_priv_object(dentry
->d_inode
)) {
652 reiserfs_error(dir
->i_sb
, "jdm-20003",
653 "OID %08x [%.*s/%.*s] doesn't have "
654 "priv flag set [parent is %sset].",
655 le32_to_cpu(INODE_PKEY(dentry
->d_inode
)->
656 k_objectid
), xadir
->d_name
.len
,
657 xadir
->d_name
.name
, namelen
, name
,
658 is_reiserfs_priv_object(xadir
->d_inode
) ? "" :
664 err
= dir
->i_op
->unlink(dir
, dentry
);
675 int reiserfs_xattr_del(struct inode
*inode
, const char *name
)
680 dir
= open_xa_dir(inode
, FL_READONLY
);
686 err
= __reiserfs_xattr_del(dir
, name
, strlen(name
));
690 inode
->i_ctime
= CURRENT_TIME_SEC
;
691 mark_inode_dirty(inode
);
698 /* The following are side effects of other operations that aren't explicitly
699 * modifying extended attributes. This includes operations such as permissions
700 * or ownership changes, object deletions, etc. */
703 reiserfs_delete_xattrs_filler(void *buf
, const char *name
, int namelen
,
704 loff_t offset
, u64 ino
, unsigned int d_type
)
706 struct dentry
*xadir
= (struct dentry
*)buf
;
708 return __reiserfs_xattr_del(xadir
, name
, namelen
);
712 /* This is called w/ inode->i_mutex downed */
713 int reiserfs_delete_xattrs(struct inode
*inode
)
715 struct dentry
*dir
, *root
;
718 /* Skip out, an xattr has no xattrs associated with it */
719 if (is_reiserfs_priv_object(inode
) ||
720 get_inode_sd_version(inode
) == STAT_DATA_V1
||
721 !reiserfs_xattrs(inode
->i_sb
)) {
724 reiserfs_read_lock_xattrs(inode
->i_sb
);
725 dir
= open_xa_dir(inode
, FL_READONLY
);
726 reiserfs_read_unlock_xattrs(inode
->i_sb
);
730 } else if (!dir
->d_inode
) {
736 err
= xattr_readdir(dir
->d_inode
, reiserfs_delete_xattrs_filler
, dir
);
742 /* Leftovers besides . and .. -- that's not good. */
743 if (dir
->d_inode
->i_nlink
<= 2) {
744 root
= get_xa_root(inode
->i_sb
, XATTR_REPLACE
);
745 reiserfs_write_lock_xattrs(inode
->i_sb
);
746 err
= vfs_rmdir(root
->d_inode
, dir
);
747 reiserfs_write_unlock_xattrs(inode
->i_sb
);
750 reiserfs_warning(inode
->i_sb
, "jdm-20006",
751 "Couldn't remove all entries in directory");
760 REISERFS_I(inode
)->i_flags
=
761 REISERFS_I(inode
)->i_flags
& ~i_has_xattr_dir
;
765 struct reiserfs_chown_buf
{
767 struct dentry
*xadir
;
771 /* XXX: If there is a better way to do this, I'd love to hear about it */
773 reiserfs_chown_xattrs_filler(void *buf
, const char *name
, int namelen
,
774 loff_t offset
, u64 ino
, unsigned int d_type
)
776 struct reiserfs_chown_buf
*chown_buf
= (struct reiserfs_chown_buf
*)buf
;
777 struct dentry
*xafile
, *xadir
= chown_buf
->xadir
;
778 struct iattr
*attrs
= chown_buf
->attrs
;
781 xafile
= lookup_one_len(name
, xadir
, namelen
);
783 return PTR_ERR(xafile
);
784 else if (!xafile
->d_inode
) {
789 if (!S_ISDIR(xafile
->d_inode
->i_mode
))
790 err
= notify_change(xafile
, attrs
);
796 int reiserfs_chown_xattrs(struct inode
*inode
, struct iattr
*attrs
)
800 struct reiserfs_chown_buf buf
;
801 unsigned int ia_valid
= attrs
->ia_valid
;
803 /* Skip out, an xattr has no xattrs associated with it */
804 if (is_reiserfs_priv_object(inode
) ||
805 get_inode_sd_version(inode
) == STAT_DATA_V1
||
806 !reiserfs_xattrs(inode
->i_sb
)) {
809 reiserfs_read_lock_xattrs(inode
->i_sb
);
810 dir
= open_xa_dir(inode
, FL_READONLY
);
811 reiserfs_read_unlock_xattrs(inode
->i_sb
);
813 if (PTR_ERR(dir
) != -ENODATA
)
816 } else if (!dir
->d_inode
) {
823 attrs
->ia_valid
&= (ATTR_UID
| ATTR_GID
| ATTR_CTIME
);
828 err
= xattr_readdir(dir
->d_inode
, reiserfs_chown_xattrs_filler
, &buf
);
834 err
= notify_change(dir
, attrs
);
841 attrs
->ia_valid
= ia_valid
;
845 /* Actual operations that are exported to VFS-land */
848 * Inode operation getxattr()
849 * Preliminary locking: we down dentry->d_inode->i_mutex
852 reiserfs_getxattr(struct dentry
* dentry
, const char *name
, void *buffer
,
855 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
858 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
859 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
862 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
863 reiserfs_read_lock_xattrs(dentry
->d_sb
);
864 err
= xah
->get(dentry
->d_inode
, name
, buffer
, size
);
865 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
866 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
871 * Inode operation setxattr()
873 * dentry->d_inode->i_mutex down
876 reiserfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
877 size_t size
, int flags
)
879 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
883 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
884 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
887 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
888 lock
= !has_xattr_dir(dentry
->d_inode
);
890 reiserfs_write_lock_xattrs(dentry
->d_sb
);
892 reiserfs_read_lock_xattrs(dentry
->d_sb
);
893 err
= xah
->set(dentry
->d_inode
, name
, value
, size
, flags
);
895 reiserfs_write_unlock_xattrs(dentry
->d_sb
);
897 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
898 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
903 * Inode operation removexattr()
905 * dentry->d_inode->i_mutex down
907 int reiserfs_removexattr(struct dentry
*dentry
, const char *name
)
910 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
912 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
913 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
916 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
917 reiserfs_read_lock_xattrs(dentry
->d_sb
);
919 /* Deletion pre-operation */
921 err
= xah
->del(dentry
->d_inode
, name
);
926 err
= reiserfs_xattr_del(dentry
->d_inode
, name
);
928 dentry
->d_inode
->i_ctime
= CURRENT_TIME_SEC
;
929 mark_inode_dirty(dentry
->d_inode
);
932 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
933 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
937 /* This is what filldir will use:
938 * r_pos will always contain the amount of space required for the entire
939 * list. If r_pos becomes larger than r_size, we need more space and we
940 * return an error indicating this. If r_pos is less than r_size, then we've
941 * filled the buffer successfully and we return success */
942 struct reiserfs_listxattr_buf
{
946 struct inode
*r_inode
;
950 reiserfs_listxattr_filler(void *buf
, const char *name
, int namelen
,
951 loff_t offset
, u64 ino
, unsigned int d_type
)
953 struct reiserfs_listxattr_buf
*b
= (struct reiserfs_listxattr_buf
*)buf
;
956 || (namelen
!= 1 && (name
[1] != '.' || namelen
!= 2))) {
957 struct reiserfs_xattr_handler
*xah
=
958 find_xattr_handler_prefix(name
);
960 return 0; /* Unsupported xattr name, skip it */
962 /* We call ->list() twice because the operation isn't required to just
963 * return the name back - we want to make sure we have enough space */
964 len
+= xah
->list(b
->r_inode
, name
, namelen
, NULL
);
967 if (b
->r_pos
+ len
+ 1 <= b
->r_size
) {
968 char *p
= b
->r_buf
+ b
->r_pos
;
969 p
+= xah
->list(b
->r_inode
, name
, namelen
, p
);
980 * Inode operation listxattr()
982 * Preliminary locking: we down dentry->d_inode->i_mutex
984 ssize_t
reiserfs_listxattr(struct dentry
* dentry
, char *buffer
, size_t size
)
988 struct reiserfs_listxattr_buf buf
;
990 if (!dentry
->d_inode
)
993 if (!reiserfs_xattrs(dentry
->d_sb
) ||
994 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
997 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
998 reiserfs_read_lock_xattrs(dentry
->d_sb
);
999 dir
= open_xa_dir(dentry
->d_inode
, FL_READONLY
);
1000 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
1003 if (err
== -ENODATA
)
1004 err
= 0; /* Not an error if there aren't any xattrs */
1009 buf
.r_size
= buffer
? size
: 0;
1011 buf
.r_inode
= dentry
->d_inode
;
1013 REISERFS_I(dentry
->d_inode
)->i_flags
|= i_has_xattr_dir
;
1015 err
= xattr_readdir(dir
->d_inode
, reiserfs_listxattr_filler
, &buf
);
1019 if (buf
.r_pos
> buf
.r_size
&& buffer
!= NULL
)
1028 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
1032 /* This is the implementation for the xattr plugin infrastructure */
1033 static LIST_HEAD(xattr_handlers
);
1034 static DEFINE_RWLOCK(handler_lock
);
1036 static struct reiserfs_xattr_handler
*find_xattr_handler_prefix(const char
1039 struct reiserfs_xattr_handler
*xah
= NULL
;
1040 struct list_head
*p
;
1042 read_lock(&handler_lock
);
1043 list_for_each(p
, &xattr_handlers
) {
1044 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1045 if (strncmp(xah
->prefix
, prefix
, strlen(xah
->prefix
)) == 0)
1050 read_unlock(&handler_lock
);
1054 static void __unregister_handlers(void)
1056 struct reiserfs_xattr_handler
*xah
;
1057 struct list_head
*p
, *tmp
;
1059 list_for_each_safe(p
, tmp
, &xattr_handlers
) {
1060 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1066 INIT_LIST_HEAD(&xattr_handlers
);
1069 int __init
reiserfs_xattr_register_handlers(void)
1072 struct reiserfs_xattr_handler
*xah
;
1073 struct list_head
*p
;
1075 write_lock(&handler_lock
);
1077 /* If we're already initialized, nothing to do */
1078 if (!list_empty(&xattr_handlers
)) {
1079 write_unlock(&handler_lock
);
1083 /* Add the handlers */
1084 list_add_tail(&user_handler
.handlers
, &xattr_handlers
);
1085 list_add_tail(&trusted_handler
.handlers
, &xattr_handlers
);
1086 #ifdef CONFIG_REISERFS_FS_SECURITY
1087 list_add_tail(&security_handler
.handlers
, &xattr_handlers
);
1089 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1090 list_add_tail(&posix_acl_access_handler
.handlers
, &xattr_handlers
);
1091 list_add_tail(&posix_acl_default_handler
.handlers
, &xattr_handlers
);
1094 /* Run initializers, if available */
1095 list_for_each(p
, &xattr_handlers
) {
1096 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1106 /* Clean up other handlers, if any failed */
1108 __unregister_handlers();
1110 write_unlock(&handler_lock
);
1114 void reiserfs_xattr_unregister_handlers(void)
1116 write_lock(&handler_lock
);
1117 __unregister_handlers();
1118 write_unlock(&handler_lock
);
1121 /* This will catch lookups from the fs root to .reiserfs_priv */
1123 xattr_lookup_poison(struct dentry
*dentry
, struct qstr
*q1
, struct qstr
*name
)
1125 struct dentry
*priv_root
= REISERFS_SB(dentry
->d_sb
)->priv_root
;
1126 if (name
->len
== priv_root
->d_name
.len
&&
1127 name
->hash
== priv_root
->d_name
.hash
&&
1128 !memcmp(name
->name
, priv_root
->d_name
.name
, name
->len
)) {
1130 } else if (q1
->len
== name
->len
&&
1131 !memcmp(q1
->name
, name
->name
, name
->len
))
1136 static struct dentry_operations xattr_lookup_poison_ops
= {
1137 .d_compare
= xattr_lookup_poison
,
1140 /* We need to take a copy of the mount flags since things like
1141 * MS_RDONLY don't get set until *after* we're called.
1142 * mount_flags != mount_options */
1143 int reiserfs_xattr_init(struct super_block
*s
, int mount_flags
)
1147 /* We need generation numbers to ensure that the oid mapping is correct
1148 * v3.5 filesystems don't have them. */
1149 if (!old_format_only(s
)) {
1150 set_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1151 } else if (reiserfs_xattrs_optional(s
)) {
1152 /* Old format filesystem, but optional xattrs have been enabled
1153 * at mount time. Error out. */
1154 reiserfs_warning(s
, "jdm-20005",
1155 "xattrs/ACLs not supported on pre v3.6 "
1156 "format filesystem. Failing mount.");
1160 /* Old format filesystem, but no optional xattrs have been enabled. This
1161 * means we silently disable xattrs on the filesystem. */
1162 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1165 /* If we don't have the privroot located yet - go find it */
1166 if (reiserfs_xattrs(s
) && !REISERFS_SB(s
)->priv_root
) {
1167 struct dentry
*dentry
;
1168 dentry
= lookup_one_len(PRIVROOT_NAME
, s
->s_root
,
1169 strlen(PRIVROOT_NAME
));
1170 if (!IS_ERR(dentry
)) {
1171 if (!(mount_flags
& MS_RDONLY
) && !dentry
->d_inode
) {
1172 struct inode
*inode
= dentry
->d_parent
->d_inode
;
1173 mutex_lock_nested(&inode
->i_mutex
,
1175 err
= inode
->i_op
->mkdir(inode
, dentry
, 0700);
1176 mutex_unlock(&inode
->i_mutex
);
1182 if (dentry
&& dentry
->d_inode
)
1183 reiserfs_info(s
, "Created %s - "
1184 "reserved for xattr "
1187 } else if (!dentry
->d_inode
) {
1192 err
= PTR_ERR(dentry
);
1194 if (!err
&& dentry
) {
1195 s
->s_root
->d_op
= &xattr_lookup_poison_ops
;
1196 reiserfs_mark_inode_private(dentry
->d_inode
);
1197 REISERFS_SB(s
)->priv_root
= dentry
;
1198 } else if (!(mount_flags
& MS_RDONLY
)) { /* xattrs are unavailable */
1199 /* If we're read-only it just means that the dir hasn't been
1200 * created. Not an error -- just no xattrs on the fs. We'll
1201 * check again if we go read-write */
1202 reiserfs_warning(s
, "jdm-20006",
1203 "xattrs/ACLs enabled and couldn't "
1204 "find/create .reiserfs_priv. "
1211 /* This is only nonzero if there was an error initializing the xattr
1212 * directory or if there is a condition where we don't support them. */
1214 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1215 clear_bit(REISERFS_XATTRS_USER
, &(REISERFS_SB(s
)->s_mount_opt
));
1216 clear_bit(REISERFS_POSIXACL
, &(REISERFS_SB(s
)->s_mount_opt
));
1219 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1220 s
->s_flags
= s
->s_flags
& ~MS_POSIXACL
;
1221 if (reiserfs_posixacl(s
))
1222 s
->s_flags
|= MS_POSIXACL
;
1227 static int reiserfs_check_acl(struct inode
*inode
, int mask
)
1229 struct posix_acl
*acl
;
1230 int error
= -EAGAIN
; /* do regular unix permission checks by default */
1232 reiserfs_read_lock_xattr_i(inode
);
1233 reiserfs_read_lock_xattrs(inode
->i_sb
);
1235 acl
= reiserfs_get_acl(inode
, ACL_TYPE_ACCESS
);
1237 reiserfs_read_unlock_xattrs(inode
->i_sb
);
1238 reiserfs_read_unlock_xattr_i(inode
);
1242 error
= posix_acl_permission(inode
, acl
, mask
);
1243 posix_acl_release(acl
);
1244 } else if (PTR_ERR(acl
) != -ENODATA
)
1245 error
= PTR_ERR(acl
);
1251 int reiserfs_permission(struct inode
*inode
, int mask
)
1254 * We don't do permission checks on the internal objects.
1255 * Permissions are determined by the "owning" object.
1257 if (is_reiserfs_priv_object(inode
))
1261 * Stat data v1 doesn't support ACLs.
1263 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
1264 return generic_permission(inode
, mask
, NULL
);
1266 return generic_permission(inode
, mask
, reiserfs_check_acl
);