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/dcache.h>
34 #include <linux/namei.h>
35 #include <linux/errno.h>
37 #include <linux/file.h>
38 #include <linux/pagemap.h>
39 #include <linux/xattr.h>
40 #include <linux/reiserfs_xattr.h>
41 #include <linux/reiserfs_acl.h>
42 #include <asm/uaccess.h>
43 #include <asm/checksum.h>
44 #include <linux/smp_lock.h>
45 #include <linux/stat.h>
46 #include <asm/semaphore.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 static struct dentry
*create_xa_root(struct super_block
*sb
)
58 struct dentry
*privroot
= dget(REISERFS_SB(sb
)->priv_root
);
59 struct dentry
*xaroot
;
61 /* This needs to be created at mount-time */
63 return ERR_PTR(-EOPNOTSUPP
);
65 xaroot
= lookup_one_len(XAROOT_NAME
, privroot
, strlen(XAROOT_NAME
));
68 } else if (!xaroot
->d_inode
) {
70 mutex_lock(&privroot
->d_inode
->i_mutex
);
72 privroot
->d_inode
->i_op
->mkdir(privroot
->d_inode
, xaroot
,
74 mutex_unlock(&privroot
->d_inode
->i_mutex
);
81 REISERFS_SB(sb
)->xattr_root
= dget(xaroot
);
89 /* This will return a dentry, or error, refering to the xa root directory.
90 * If the xa root doesn't exist yet, the dentry will be returned without
91 * an associated inode. This dentry can be used with ->mkdir to create
92 * the xa directory. */
93 static struct dentry
*__get_xa_root(struct super_block
*s
)
95 struct dentry
*privroot
= dget(REISERFS_SB(s
)->priv_root
);
96 struct dentry
*xaroot
= NULL
;
98 if (IS_ERR(privroot
) || !privroot
)
101 xaroot
= lookup_one_len(XAROOT_NAME
, privroot
, strlen(XAROOT_NAME
));
102 if (IS_ERR(xaroot
)) {
104 } else if (!xaroot
->d_inode
) {
110 REISERFS_SB(s
)->xattr_root
= dget(xaroot
);
117 /* Returns the dentry (or NULL) referring to the root of the extended
118 * attribute directory tree. If it has already been retrieved, it is used.
119 * Otherwise, we attempt to retrieve it from disk. It may also return
120 * a pointer-encoded error.
122 static inline struct dentry
*get_xa_root(struct super_block
*s
)
124 struct dentry
*dentry
= dget(REISERFS_SB(s
)->xattr_root
);
127 dentry
= __get_xa_root(s
);
132 /* Opens the directory corresponding to the inode's extended attribute store.
133 * If flags allow, the tree to the directory may be created. If creation is
134 * prohibited, -ENODATA is returned. */
135 static struct dentry
*open_xa_dir(const struct inode
*inode
, int flags
)
137 struct dentry
*xaroot
, *xadir
;
140 xaroot
= get_xa_root(inode
->i_sb
);
141 if (IS_ERR(xaroot
)) {
143 } else if (!xaroot
) {
144 if (flags
== 0 || flags
& XATTR_CREATE
) {
145 xaroot
= create_xa_root(inode
->i_sb
);
150 return ERR_PTR(-ENODATA
);
153 /* ok, we have xaroot open */
155 snprintf(namebuf
, sizeof(namebuf
), "%X.%X",
156 le32_to_cpu(INODE_PKEY(inode
)->k_objectid
),
157 inode
->i_generation
);
158 xadir
= lookup_one_len(namebuf
, xaroot
, strlen(namebuf
));
164 if (!xadir
->d_inode
) {
166 if (flags
== 0 || flags
& XATTR_CREATE
) {
167 /* Although there is nothing else trying to create this directory,
168 * another directory with the same hash may be created, so we need
169 * to protect against that */
171 xaroot
->d_inode
->i_op
->mkdir(xaroot
->d_inode
, xadir
,
179 if (!xadir
->d_inode
) {
182 return ERR_PTR(-ENODATA
);
190 /* Returns a dentry corresponding to a specific extended attribute file
191 * for the inode. If flags allow, the file is created. Otherwise, a
192 * valid or negative dentry, or an error is returned. */
193 static struct dentry
*get_xa_file_dentry(const struct inode
*inode
,
194 const char *name
, int flags
)
196 struct dentry
*xadir
, *xafile
;
199 xadir
= open_xa_dir(inode
, flags
);
201 return ERR_PTR(PTR_ERR(xadir
));
202 } else if (xadir
&& !xadir
->d_inode
) {
204 return ERR_PTR(-ENODATA
);
207 xafile
= lookup_one_len(name
, xadir
, strlen(name
));
208 if (IS_ERR(xafile
)) {
210 return ERR_PTR(PTR_ERR(xafile
));
213 if (xafile
->d_inode
) { /* file exists */
214 if (flags
& XATTR_CREATE
) {
219 } else if (flags
& XATTR_REPLACE
|| flags
& FL_READONLY
) {
222 /* inode->i_mutex is down, so nothing else can try to create
224 err
= xadir
->d_inode
->i_op
->create(xadir
->d_inode
, xafile
,
225 0700 | S_IFREG
, NULL
);
236 xafile
= ERR_PTR(err
);
240 /* Opens a file pointer to the attribute associated with inode */
241 static struct file
*open_xa_file(const struct inode
*inode
, const char *name
,
244 struct dentry
*xafile
;
247 xafile
= get_xa_file_dentry(inode
, name
, flags
);
249 return ERR_PTR(PTR_ERR(xafile
));
250 else if (!xafile
->d_inode
) {
252 return ERR_PTR(-ENODATA
);
255 fp
= dentry_open(xafile
, NULL
, O_RDWR
);
256 /* dentry_open dputs the dentry if it fails */
262 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
263 * we need to drop the path before calling the filldir struct. That
264 * would be a big performance hit to the non-xattr case, so I've copied
265 * the whole thing for now. --clm
267 * the big difference is that I go backwards through the directory,
268 * and don't mess with f->f_pos, but the idea is the same. Do some
269 * action on each and every entry in the directory.
271 * we're called with i_mutex held, so there are no worries about the directory
272 * changing underneath us.
274 static int __xattr_readdir(struct file
*filp
, void *dirent
, filldir_t filldir
)
276 struct inode
*inode
= filp
->f_dentry
->d_inode
;
277 struct cpu_key pos_key
; /* key of current position in the directory (key of directory entry) */
278 INITIALIZE_PATH(path_to_entry
);
279 struct buffer_head
*bh
;
281 struct item_head
*ih
, tmp_ih
;
285 char small_buf
[32]; /* avoid kmalloc if we can */
286 struct reiserfs_de_head
*deh
;
291 struct reiserfs_dir_entry de
;
293 /* form key for search the next directory entry using f_pos field of
295 next_pos
= max_reiserfs_offset(inode
);
299 if (next_pos
<= DOT_DOT_OFFSET
)
301 make_cpu_key(&pos_key
, inode
, next_pos
, TYPE_DIRENTRY
, 3);
304 search_by_entry_key(inode
->i_sb
, &pos_key
, &path_to_entry
,
306 if (search_res
== IO_ERROR
) {
307 // FIXME: we could just skip part of directory which could
309 pathrelse(&path_to_entry
);
313 if (search_res
== NAME_NOT_FOUND
)
316 set_de_name_and_namelen(&de
);
317 entry_num
= de
.de_entry_num
;
318 deh
= &(de
.de_deh
[entry_num
]);
323 if (!is_direntry_le_ih(ih
)) {
324 reiserfs_warning(inode
->i_sb
, "not direntry %h", ih
);
327 copy_item_head(&tmp_ih
, ih
);
329 /* we must have found item, that is item of this directory, */
330 RFALSE(COMP_SHORT_KEYS(&(ih
->ih_key
), &pos_key
),
331 "vs-9000: found item %h does not match to dir we readdir %K",
334 if (deh_offset(deh
) <= DOT_DOT_OFFSET
) {
338 /* look for the previous entry in the directory */
339 next_pos
= deh_offset(deh
) - 1;
341 if (!de_visible(deh
))
342 /* it is hidden entry */
345 d_reclen
= entry_length(bh
, ih
, entry_num
);
346 d_name
= B_I_DEH_ENTRY_FILE_NAME(bh
, ih
, deh
);
347 d_off
= deh_offset(deh
);
348 d_ino
= deh_objectid(deh
);
350 if (!d_name
[d_reclen
- 1])
351 d_reclen
= strlen(d_name
);
353 if (d_reclen
> REISERFS_MAX_NAME(inode
->i_sb
->s_blocksize
)) {
354 /* too big to send back to VFS */
358 /* Ignore the .reiserfs_priv entry */
359 if (reiserfs_xattrs(inode
->i_sb
) &&
360 !old_format_only(inode
->i_sb
) &&
362 le32_to_cpu(INODE_PKEY
363 (REISERFS_SB(inode
->i_sb
)->priv_root
->d_inode
)->
367 if (d_reclen
<= 32) {
368 local_buf
= small_buf
;
371 reiserfs_kmalloc(d_reclen
, GFP_NOFS
, inode
->i_sb
);
373 pathrelse(&path_to_entry
);
376 if (item_moved(&tmp_ih
, &path_to_entry
)) {
377 reiserfs_kfree(local_buf
, d_reclen
,
380 /* sigh, must retry. Do this same offset again */
386 // Note, that we copy name to user space via temporary
387 // buffer (local_buf) because filldir will block if
388 // user space buffer is swapped out. At that time
389 // entry can move to somewhere else
390 memcpy(local_buf
, d_name
, d_reclen
);
392 /* the filldir function might need to start transactions,
393 * or do who knows what. Release the path now that we've
394 * copied all the important stuff out of the deh
396 pathrelse(&path_to_entry
);
398 if (filldir(dirent
, local_buf
, d_reclen
, d_off
, d_ino
,
400 if (local_buf
!= small_buf
) {
401 reiserfs_kfree(local_buf
, d_reclen
,
406 if (local_buf
!= small_buf
) {
407 reiserfs_kfree(local_buf
, d_reclen
, inode
->i_sb
);
412 pathrelse(&path_to_entry
);
417 * this could be done with dedicated readdir ops for the xattr files,
418 * but I want to get something working asap
419 * this is stolen from vfs_readdir
423 int xattr_readdir(struct file
*file
, filldir_t filler
, void *buf
)
425 struct inode
*inode
= file
->f_dentry
->d_inode
;
427 if (!file
->f_op
|| !file
->f_op
->readdir
)
429 mutex_lock(&inode
->i_mutex
);
430 // down(&inode->i_zombie);
432 if (!IS_DEADDIR(inode
)) {
434 res
= __xattr_readdir(file
, buf
, filler
);
437 // up(&inode->i_zombie);
438 mutex_unlock(&inode
->i_mutex
);
443 /* Internal operations on file data */
444 static inline void reiserfs_put_page(struct page
*page
)
447 page_cache_release(page
);
450 static struct page
*reiserfs_get_page(struct inode
*dir
, unsigned long n
)
452 struct address_space
*mapping
= dir
->i_mapping
;
454 /* We can deadlock if we try to free dentries,
455 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
456 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
457 page
= read_cache_page(mapping
, n
,
458 (filler_t
*) mapping
->a_ops
->readpage
, NULL
);
460 wait_on_page_locked(page
);
462 if (!PageUptodate(page
))
471 reiserfs_put_page(page
);
472 return ERR_PTR(-EIO
);
475 static inline __u32
xattr_hash(const char *msg
, int len
)
477 return csum_partial(msg
, len
, 0);
480 /* Generic extended attribute operations that can be used by xa plugins */
483 * inode->i_mutex: down
486 reiserfs_xattr_set(struct inode
*inode
, const char *name
, const void *buffer
,
487 size_t buffer_size
, int flags
)
493 struct address_space
*mapping
;
495 size_t buffer_pos
= 0;
496 struct inode
*xinode
;
497 struct iattr newattrs
;
500 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
503 /* Empty xattrs are ok, they're just empty files, no hash */
504 if (buffer
&& buffer_size
)
505 xahash
= xattr_hash(buffer
, buffer_size
);
508 fp
= open_xa_file(inode
, name
, flags
);
514 xinode
= fp
->f_dentry
->d_inode
;
515 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
517 /* we need to copy it off.. */
518 if (xinode
->i_nlink
> 1) {
520 err
= reiserfs_xattr_del(inode
, name
);
523 /* We just killed the old one, we're not replacing anymore */
524 if (flags
& XATTR_REPLACE
)
525 flags
&= ~XATTR_REPLACE
;
529 /* Resize it so we're ok to write there */
530 newattrs
.ia_size
= buffer_size
;
531 newattrs
.ia_valid
= ATTR_SIZE
| ATTR_CTIME
;
532 mutex_lock(&xinode
->i_mutex
);
533 err
= notify_change(fp
->f_dentry
, &newattrs
);
537 mapping
= xinode
->i_mapping
;
538 while (buffer_pos
< buffer_size
|| buffer_pos
== 0) {
541 size_t page_offset
= (file_pos
& (PAGE_CACHE_SIZE
- 1));
542 if (buffer_size
- buffer_pos
> PAGE_CACHE_SIZE
)
543 chunk
= PAGE_CACHE_SIZE
;
545 chunk
= buffer_size
- buffer_pos
;
547 page
= reiserfs_get_page(xinode
, file_pos
>> PAGE_CACHE_SHIFT
);
554 data
= page_address(page
);
557 struct reiserfs_xattr_header
*rxh
;
558 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
559 if (chunk
+ skip
> PAGE_CACHE_SIZE
)
560 chunk
= PAGE_CACHE_SIZE
- skip
;
561 rxh
= (struct reiserfs_xattr_header
*)data
;
562 rxh
->h_magic
= cpu_to_le32(REISERFS_XATTR_MAGIC
);
563 rxh
->h_hash
= cpu_to_le32(xahash
);
566 err
= mapping
->a_ops
->prepare_write(fp
, page
, page_offset
,
567 page_offset
+ chunk
+ skip
);
570 memcpy(data
+ skip
, buffer
+ buffer_pos
, chunk
);
572 mapping
->a_ops
->commit_write(fp
, page
, page_offset
,
573 page_offset
+ chunk
+
577 reiserfs_put_page(page
);
581 if (err
|| buffer_size
== 0 || !buffer
)
585 /* We can't mark the inode dirty if it's not hashed. This is the case
586 * when we're inheriting the default ACL. If we dirty it, the inode
587 * gets marked dirty, but won't (ever) make it onto the dirty list until
588 * it's synced explicitly to clear I_DIRTY. This is bad. */
589 if (!hlist_unhashed(&inode
->i_hash
)) {
590 inode
->i_ctime
= CURRENT_TIME_SEC
;
591 mark_inode_dirty(inode
);
595 mutex_unlock(&xinode
->i_mutex
);
603 * inode->i_mutex: down
606 reiserfs_xattr_get(const struct inode
*inode
, const char *name
, void *buffer
,
613 size_t buffer_pos
= 0;
615 struct inode
*xinode
;
621 /* We can't have xattrs attached to v1 items since they don't have
622 * generation numbers */
623 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
626 fp
= open_xa_file(inode
, name
, FL_READONLY
);
632 xinode
= fp
->f_dentry
->d_inode
;
633 isize
= xinode
->i_size
;
634 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
636 /* Just return the size needed */
637 if (buffer
== NULL
) {
638 err
= isize
- sizeof(struct reiserfs_xattr_header
);
642 if (buffer_size
< isize
- sizeof(struct reiserfs_xattr_header
)) {
647 while (file_pos
< isize
) {
651 if (isize
- file_pos
> PAGE_CACHE_SIZE
)
652 chunk
= PAGE_CACHE_SIZE
;
654 chunk
= isize
- file_pos
;
656 page
= reiserfs_get_page(xinode
, file_pos
>> PAGE_CACHE_SHIFT
);
663 data
= page_address(page
);
665 struct reiserfs_xattr_header
*rxh
=
666 (struct reiserfs_xattr_header
*)data
;
667 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
669 /* Magic doesn't match up.. */
670 if (rxh
->h_magic
!= cpu_to_le32(REISERFS_XATTR_MAGIC
)) {
672 reiserfs_put_page(page
);
673 reiserfs_warning(inode
->i_sb
,
674 "Invalid magic for xattr (%s) "
675 "associated with %k", name
,
680 hash
= le32_to_cpu(rxh
->h_hash
);
682 memcpy(buffer
+ buffer_pos
, data
+ skip
, chunk
);
684 reiserfs_put_page(page
);
689 err
= isize
- sizeof(struct reiserfs_xattr_header
);
691 if (xattr_hash(buffer
, isize
- sizeof(struct reiserfs_xattr_header
)) !=
693 reiserfs_warning(inode
->i_sb
,
694 "Invalid hash for xattr (%s) associated "
695 "with %k", name
, INODE_PKEY(inode
));
707 __reiserfs_xattr_del(struct dentry
*xadir
, const char *name
, int namelen
)
709 struct dentry
*dentry
;
710 struct inode
*dir
= xadir
->d_inode
;
713 dentry
= lookup_one_len(name
, xadir
, namelen
);
714 if (IS_ERR(dentry
)) {
715 err
= PTR_ERR(dentry
);
717 } else if (!dentry
->d_inode
) {
722 /* Skip directories.. */
723 if (S_ISDIR(dentry
->d_inode
->i_mode
))
726 if (!is_reiserfs_priv_object(dentry
->d_inode
)) {
727 reiserfs_warning(dir
->i_sb
, "OID %08x [%.*s/%.*s] doesn't have "
728 "priv flag set [parent is %sset].",
729 le32_to_cpu(INODE_PKEY(dentry
->d_inode
)->
730 k_objectid
), xadir
->d_name
.len
,
731 xadir
->d_name
.name
, namelen
, name
,
732 is_reiserfs_priv_object(xadir
->
739 err
= dir
->i_op
->unlink(dir
, dentry
);
750 int reiserfs_xattr_del(struct inode
*inode
, const char *name
)
755 dir
= open_xa_dir(inode
, FL_READONLY
);
761 err
= __reiserfs_xattr_del(dir
, name
, strlen(name
));
765 inode
->i_ctime
= CURRENT_TIME_SEC
;
766 mark_inode_dirty(inode
);
773 /* The following are side effects of other operations that aren't explicitly
774 * modifying extended attributes. This includes operations such as permissions
775 * or ownership changes, object deletions, etc. */
778 reiserfs_delete_xattrs_filler(void *buf
, const char *name
, int namelen
,
779 loff_t offset
, ino_t ino
, unsigned int d_type
)
781 struct dentry
*xadir
= (struct dentry
*)buf
;
783 return __reiserfs_xattr_del(xadir
, name
, namelen
);
787 /* This is called w/ inode->i_mutex downed */
788 int reiserfs_delete_xattrs(struct inode
*inode
)
791 struct dentry
*dir
, *root
;
794 /* Skip out, an xattr has no xattrs associated with it */
795 if (is_reiserfs_priv_object(inode
) ||
796 get_inode_sd_version(inode
) == STAT_DATA_V1
||
797 !reiserfs_xattrs(inode
->i_sb
)) {
800 reiserfs_read_lock_xattrs(inode
->i_sb
);
801 dir
= open_xa_dir(inode
, FL_READONLY
);
802 reiserfs_read_unlock_xattrs(inode
->i_sb
);
806 } else if (!dir
->d_inode
) {
811 fp
= dentry_open(dir
, NULL
, O_RDWR
);
814 /* dentry_open dputs the dentry if it fails */
819 err
= xattr_readdir(fp
, reiserfs_delete_xattrs_filler
, dir
);
825 /* Leftovers besides . and .. -- that's not good. */
826 if (dir
->d_inode
->i_nlink
<= 2) {
827 root
= get_xa_root(inode
->i_sb
);
828 reiserfs_write_lock_xattrs(inode
->i_sb
);
829 err
= vfs_rmdir(root
->d_inode
, dir
);
830 reiserfs_write_unlock_xattrs(inode
->i_sb
);
833 reiserfs_warning(inode
->i_sb
,
834 "Couldn't remove all entries in directory");
843 REISERFS_I(inode
)->i_flags
=
844 REISERFS_I(inode
)->i_flags
& ~i_has_xattr_dir
;
848 struct reiserfs_chown_buf
{
850 struct dentry
*xadir
;
854 /* XXX: If there is a better way to do this, I'd love to hear about it */
856 reiserfs_chown_xattrs_filler(void *buf
, const char *name
, int namelen
,
857 loff_t offset
, ino_t ino
, unsigned int d_type
)
859 struct reiserfs_chown_buf
*chown_buf
= (struct reiserfs_chown_buf
*)buf
;
860 struct dentry
*xafile
, *xadir
= chown_buf
->xadir
;
861 struct iattr
*attrs
= chown_buf
->attrs
;
864 xafile
= lookup_one_len(name
, xadir
, namelen
);
866 return PTR_ERR(xafile
);
867 else if (!xafile
->d_inode
) {
872 if (!S_ISDIR(xafile
->d_inode
->i_mode
))
873 err
= notify_change(xafile
, attrs
);
879 int reiserfs_chown_xattrs(struct inode
*inode
, struct iattr
*attrs
)
884 struct reiserfs_chown_buf buf
;
885 unsigned int ia_valid
= attrs
->ia_valid
;
887 /* Skip out, an xattr has no xattrs associated with it */
888 if (is_reiserfs_priv_object(inode
) ||
889 get_inode_sd_version(inode
) == STAT_DATA_V1
||
890 !reiserfs_xattrs(inode
->i_sb
)) {
893 reiserfs_read_lock_xattrs(inode
->i_sb
);
894 dir
= open_xa_dir(inode
, FL_READONLY
);
895 reiserfs_read_unlock_xattrs(inode
->i_sb
);
897 if (PTR_ERR(dir
) != -ENODATA
)
900 } else if (!dir
->d_inode
) {
905 fp
= dentry_open(dir
, NULL
, O_RDWR
);
908 /* dentry_open dputs the dentry if it fails */
914 attrs
->ia_valid
&= (ATTR_UID
| ATTR_GID
| ATTR_CTIME
);
919 err
= xattr_readdir(fp
, reiserfs_chown_xattrs_filler
, &buf
);
925 err
= notify_change(dir
, attrs
);
932 attrs
->ia_valid
= ia_valid
;
936 /* Actual operations that are exported to VFS-land */
939 * Inode operation getxattr()
940 * Preliminary locking: we down dentry->d_inode->i_mutex
943 reiserfs_getxattr(struct dentry
* dentry
, const char *name
, void *buffer
,
946 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
949 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
950 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
953 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
954 reiserfs_read_lock_xattrs(dentry
->d_sb
);
955 err
= xah
->get(dentry
->d_inode
, name
, buffer
, size
);
956 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
957 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
962 * Inode operation setxattr()
964 * dentry->d_inode->i_mutex down
967 reiserfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
968 size_t size
, int flags
)
970 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
974 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
975 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
978 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
979 lock
= !has_xattr_dir(dentry
->d_inode
);
981 reiserfs_write_lock_xattrs(dentry
->d_sb
);
983 reiserfs_read_lock_xattrs(dentry
->d_sb
);
984 err
= xah
->set(dentry
->d_inode
, name
, value
, size
, flags
);
986 reiserfs_write_unlock_xattrs(dentry
->d_sb
);
988 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
989 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
994 * Inode operation removexattr()
996 * dentry->d_inode->i_mutex down
998 int reiserfs_removexattr(struct dentry
*dentry
, const char *name
)
1001 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
1003 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
1004 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
1007 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
1008 reiserfs_read_lock_xattrs(dentry
->d_sb
);
1010 /* Deletion pre-operation */
1012 err
= xah
->del(dentry
->d_inode
, name
);
1017 err
= reiserfs_xattr_del(dentry
->d_inode
, name
);
1019 dentry
->d_inode
->i_ctime
= CURRENT_TIME_SEC
;
1020 mark_inode_dirty(dentry
->d_inode
);
1023 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
1024 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
1028 /* This is what filldir will use:
1029 * r_pos will always contain the amount of space required for the entire
1030 * list. If r_pos becomes larger than r_size, we need more space and we
1031 * return an error indicating this. If r_pos is less than r_size, then we've
1032 * filled the buffer successfully and we return success */
1033 struct reiserfs_listxattr_buf
{
1037 struct inode
*r_inode
;
1041 reiserfs_listxattr_filler(void *buf
, const char *name
, int namelen
,
1042 loff_t offset
, ino_t ino
, unsigned int d_type
)
1044 struct reiserfs_listxattr_buf
*b
= (struct reiserfs_listxattr_buf
*)buf
;
1047 || (namelen
!= 1 && (name
[1] != '.' || namelen
!= 2))) {
1048 struct reiserfs_xattr_handler
*xah
=
1049 find_xattr_handler_prefix(name
);
1051 return 0; /* Unsupported xattr name, skip it */
1053 /* We call ->list() twice because the operation isn't required to just
1054 * return the name back - we want to make sure we have enough space */
1055 len
+= xah
->list(b
->r_inode
, name
, namelen
, NULL
);
1058 if (b
->r_pos
+ len
+ 1 <= b
->r_size
) {
1059 char *p
= b
->r_buf
+ b
->r_pos
;
1060 p
+= xah
->list(b
->r_inode
, name
, namelen
, p
);
1063 b
->r_pos
+= len
+ 1;
1071 * Inode operation listxattr()
1073 * Preliminary locking: we down dentry->d_inode->i_mutex
1075 ssize_t
reiserfs_listxattr(struct dentry
* dentry
, char *buffer
, size_t size
)
1080 struct reiserfs_listxattr_buf buf
;
1082 if (!dentry
->d_inode
)
1085 if (!reiserfs_xattrs(dentry
->d_sb
) ||
1086 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
1089 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
1090 reiserfs_read_lock_xattrs(dentry
->d_sb
);
1091 dir
= open_xa_dir(dentry
->d_inode
, FL_READONLY
);
1092 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
1095 if (err
== -ENODATA
)
1096 err
= 0; /* Not an error if there aren't any xattrs */
1100 fp
= dentry_open(dir
, NULL
, O_RDWR
);
1103 /* dentry_open dputs the dentry if it fails */
1108 buf
.r_size
= buffer
? size
: 0;
1110 buf
.r_inode
= dentry
->d_inode
;
1112 REISERFS_I(dentry
->d_inode
)->i_flags
|= i_has_xattr_dir
;
1114 err
= xattr_readdir(fp
, reiserfs_listxattr_filler
, &buf
);
1118 if (buf
.r_pos
> buf
.r_size
&& buffer
!= NULL
)
1127 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
1131 /* This is the implementation for the xattr plugin infrastructure */
1132 static struct list_head xattr_handlers
= LIST_HEAD_INIT(xattr_handlers
);
1133 static DEFINE_RWLOCK(handler_lock
);
1135 static struct reiserfs_xattr_handler
*find_xattr_handler_prefix(const char
1138 struct reiserfs_xattr_handler
*xah
= NULL
;
1139 struct list_head
*p
;
1141 read_lock(&handler_lock
);
1142 list_for_each(p
, &xattr_handlers
) {
1143 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1144 if (strncmp(xah
->prefix
, prefix
, strlen(xah
->prefix
)) == 0)
1149 read_unlock(&handler_lock
);
1153 static void __unregister_handlers(void)
1155 struct reiserfs_xattr_handler
*xah
;
1156 struct list_head
*p
, *tmp
;
1158 list_for_each_safe(p
, tmp
, &xattr_handlers
) {
1159 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1165 INIT_LIST_HEAD(&xattr_handlers
);
1168 int __init
reiserfs_xattr_register_handlers(void)
1171 struct reiserfs_xattr_handler
*xah
;
1172 struct list_head
*p
;
1174 write_lock(&handler_lock
);
1176 /* If we're already initialized, nothing to do */
1177 if (!list_empty(&xattr_handlers
)) {
1178 write_unlock(&handler_lock
);
1182 /* Add the handlers */
1183 list_add_tail(&user_handler
.handlers
, &xattr_handlers
);
1184 list_add_tail(&trusted_handler
.handlers
, &xattr_handlers
);
1185 #ifdef CONFIG_REISERFS_FS_SECURITY
1186 list_add_tail(&security_handler
.handlers
, &xattr_handlers
);
1188 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1189 list_add_tail(&posix_acl_access_handler
.handlers
, &xattr_handlers
);
1190 list_add_tail(&posix_acl_default_handler
.handlers
, &xattr_handlers
);
1193 /* Run initializers, if available */
1194 list_for_each(p
, &xattr_handlers
) {
1195 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1205 /* Clean up other handlers, if any failed */
1207 __unregister_handlers();
1209 write_unlock(&handler_lock
);
1213 void reiserfs_xattr_unregister_handlers(void)
1215 write_lock(&handler_lock
);
1216 __unregister_handlers();
1217 write_unlock(&handler_lock
);
1220 /* This will catch lookups from the fs root to .reiserfs_priv */
1222 xattr_lookup_poison(struct dentry
*dentry
, struct qstr
*q1
, struct qstr
*name
)
1224 struct dentry
*priv_root
= REISERFS_SB(dentry
->d_sb
)->priv_root
;
1225 if (name
->len
== priv_root
->d_name
.len
&&
1226 name
->hash
== priv_root
->d_name
.hash
&&
1227 !memcmp(name
->name
, priv_root
->d_name
.name
, name
->len
)) {
1229 } else if (q1
->len
== name
->len
&&
1230 !memcmp(q1
->name
, name
->name
, name
->len
))
1235 static struct dentry_operations xattr_lookup_poison_ops
= {
1236 .d_compare
= xattr_lookup_poison
,
1239 /* We need to take a copy of the mount flags since things like
1240 * MS_RDONLY don't get set until *after* we're called.
1241 * mount_flags != mount_options */
1242 int reiserfs_xattr_init(struct super_block
*s
, int mount_flags
)
1246 /* We need generation numbers to ensure that the oid mapping is correct
1247 * v3.5 filesystems don't have them. */
1248 if (!old_format_only(s
)) {
1249 set_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1250 } else if (reiserfs_xattrs_optional(s
)) {
1251 /* Old format filesystem, but optional xattrs have been enabled
1252 * at mount time. Error out. */
1253 reiserfs_warning(s
, "xattrs/ACLs not supported on pre v3.6 "
1254 "format filesystem. Failing mount.");
1258 /* Old format filesystem, but no optional xattrs have been enabled. This
1259 * means we silently disable xattrs on the filesystem. */
1260 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1263 /* If we don't have the privroot located yet - go find it */
1264 if (reiserfs_xattrs(s
) && !REISERFS_SB(s
)->priv_root
) {
1265 struct dentry
*dentry
;
1266 dentry
= lookup_one_len(PRIVROOT_NAME
, s
->s_root
,
1267 strlen(PRIVROOT_NAME
));
1268 if (!IS_ERR(dentry
)) {
1269 if (!(mount_flags
& MS_RDONLY
) && !dentry
->d_inode
) {
1270 struct inode
*inode
= dentry
->d_parent
->d_inode
;
1271 mutex_lock(&inode
->i_mutex
);
1272 err
= inode
->i_op
->mkdir(inode
, dentry
, 0700);
1273 mutex_unlock(&inode
->i_mutex
);
1279 if (dentry
&& dentry
->d_inode
)
1281 "Created %s on %s - reserved for "
1286 } else if (!dentry
->d_inode
) {
1291 err
= PTR_ERR(dentry
);
1293 if (!err
&& dentry
) {
1294 s
->s_root
->d_op
= &xattr_lookup_poison_ops
;
1295 reiserfs_mark_inode_private(dentry
->d_inode
);
1296 REISERFS_SB(s
)->priv_root
= dentry
;
1297 } else if (!(mount_flags
& MS_RDONLY
)) { /* xattrs are unavailable */
1298 /* If we're read-only it just means that the dir hasn't been
1299 * created. Not an error -- just no xattrs on the fs. We'll
1300 * check again if we go read-write */
1301 reiserfs_warning(s
, "xattrs/ACLs enabled and couldn't "
1302 "find/create .reiserfs_priv. Failing mount.");
1308 /* This is only nonzero if there was an error initializing the xattr
1309 * directory or if there is a condition where we don't support them. */
1311 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1312 clear_bit(REISERFS_XATTRS_USER
, &(REISERFS_SB(s
)->s_mount_opt
));
1313 clear_bit(REISERFS_POSIXACL
, &(REISERFS_SB(s
)->s_mount_opt
));
1316 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1317 s
->s_flags
= s
->s_flags
& ~MS_POSIXACL
;
1318 if (reiserfs_posixacl(s
))
1319 s
->s_flags
|= MS_POSIXACL
;
1325 __reiserfs_permission(struct inode
*inode
, int mask
, struct nameidata
*nd
,
1328 umode_t mode
= inode
->i_mode
;
1330 if (mask
& MAY_WRITE
) {
1332 * Nobody gets write access to a read-only fs.
1334 if (IS_RDONLY(inode
) &&
1335 (S_ISREG(mode
) || S_ISDIR(mode
) || S_ISLNK(mode
)))
1339 * Nobody gets write access to an immutable file.
1341 if (IS_IMMUTABLE(inode
))
1345 /* We don't do permission checks on the internal objects.
1346 * Permissions are determined by the "owning" object. */
1347 if (is_reiserfs_priv_object(inode
))
1350 if (current
->fsuid
== inode
->i_uid
) {
1352 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1353 } else if (reiserfs_posixacl(inode
->i_sb
) &&
1354 get_inode_sd_version(inode
) != STAT_DATA_V1
) {
1355 struct posix_acl
*acl
;
1357 /* ACL can't contain additional permissions if
1358 the ACL_MASK entry is 0 */
1359 if (!(mode
& S_IRWXG
))
1363 reiserfs_read_lock_xattr_i(inode
);
1364 reiserfs_read_lock_xattrs(inode
->i_sb
);
1366 acl
= reiserfs_get_acl(inode
, ACL_TYPE_ACCESS
);
1368 reiserfs_read_unlock_xattrs(inode
->i_sb
);
1369 reiserfs_read_unlock_xattr_i(inode
);
1372 if (PTR_ERR(acl
) == -ENODATA
)
1374 return PTR_ERR(acl
);
1378 int err
= posix_acl_permission(inode
, acl
, mask
);
1379 posix_acl_release(acl
);
1380 if (err
== -EACCES
) {
1381 goto check_capabilities
;
1390 if (in_group_p(inode
->i_gid
))
1395 * If the DACs are ok we don't need any capability check.
1397 if (((mode
& mask
& (MAY_READ
| MAY_WRITE
| MAY_EXEC
)) == mask
))
1402 * Read/write DACs are always overridable.
1403 * Executable DACs are overridable if at least one exec bit is set.
1405 if (!(mask
& MAY_EXEC
) ||
1406 (inode
->i_mode
& S_IXUGO
) || S_ISDIR(inode
->i_mode
))
1407 if (capable(CAP_DAC_OVERRIDE
))
1411 * Searching includes executable on directories, else just read.
1413 if (mask
== MAY_READ
|| (S_ISDIR(inode
->i_mode
) && !(mask
& MAY_WRITE
)))
1414 if (capable(CAP_DAC_READ_SEARCH
))
1420 int reiserfs_permission(struct inode
*inode
, int mask
, struct nameidata
*nd
)
1422 return __reiserfs_permission(inode
, mask
, nd
, 1);
1426 reiserfs_permission_locked(struct inode
*inode
, int mask
, struct nameidata
*nd
)
1428 return __reiserfs_permission(inode
, mask
, nd
, 0);