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 down(&privroot
->d_inode
->i_sem
);
72 privroot
->d_inode
->i_op
->mkdir(privroot
->d_inode
, xaroot
,
74 up(&privroot
->d_inode
->i_sem
);
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 retreived, it is used.
119 * Otherwise, we attempt to retreive 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_sem 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_sem 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
)
430 // down(&inode->i_zombie);
432 if (!IS_DEADDIR(inode
)) {
434 res
= __xattr_readdir(file
, buf
, filler
);
437 // up(&inode->i_zombie);
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
->flags
= (mapping
->flags
& ~__GFP_BITS_MASK
) | 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 */
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 (IS_RDONLY(inode
))
503 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
506 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
509 /* Empty xattrs are ok, they're just empty files, no hash */
510 if (buffer
&& buffer_size
)
511 xahash
= xattr_hash(buffer
, buffer_size
);
514 fp
= open_xa_file(inode
, name
, flags
);
520 xinode
= fp
->f_dentry
->d_inode
;
521 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
523 /* we need to copy it off.. */
524 if (xinode
->i_nlink
> 1) {
526 err
= reiserfs_xattr_del(inode
, name
);
529 /* We just killed the old one, we're not replacing anymore */
530 if (flags
& XATTR_REPLACE
)
531 flags
&= ~XATTR_REPLACE
;
535 /* Resize it so we're ok to write there */
536 newattrs
.ia_size
= buffer_size
;
537 newattrs
.ia_valid
= ATTR_SIZE
| ATTR_CTIME
;
538 down(&xinode
->i_sem
);
539 err
= notify_change(fp
->f_dentry
, &newattrs
);
543 mapping
= xinode
->i_mapping
;
544 while (buffer_pos
< buffer_size
|| buffer_pos
== 0) {
547 size_t page_offset
= (file_pos
& (PAGE_CACHE_SIZE
- 1));
548 if (buffer_size
- buffer_pos
> PAGE_CACHE_SIZE
)
549 chunk
= PAGE_CACHE_SIZE
;
551 chunk
= buffer_size
- buffer_pos
;
553 page
= reiserfs_get_page(xinode
, file_pos
>> PAGE_CACHE_SHIFT
);
560 data
= page_address(page
);
563 struct reiserfs_xattr_header
*rxh
;
564 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
565 if (chunk
+ skip
> PAGE_CACHE_SIZE
)
566 chunk
= PAGE_CACHE_SIZE
- skip
;
567 rxh
= (struct reiserfs_xattr_header
*)data
;
568 rxh
->h_magic
= cpu_to_le32(REISERFS_XATTR_MAGIC
);
569 rxh
->h_hash
= cpu_to_le32(xahash
);
572 err
= mapping
->a_ops
->prepare_write(fp
, page
, page_offset
,
573 page_offset
+ chunk
+ skip
);
576 memcpy(data
+ skip
, buffer
+ buffer_pos
, chunk
);
578 mapping
->a_ops
->commit_write(fp
, page
, page_offset
,
579 page_offset
+ chunk
+
583 reiserfs_put_page(page
);
587 if (err
|| buffer_size
== 0 || !buffer
)
591 /* We can't mark the inode dirty if it's not hashed. This is the case
592 * when we're inheriting the default ACL. If we dirty it, the inode
593 * gets marked dirty, but won't (ever) make it onto the dirty list until
594 * it's synced explicitly to clear I_DIRTY. This is bad. */
595 if (!hlist_unhashed(&inode
->i_hash
)) {
596 inode
->i_ctime
= CURRENT_TIME_SEC
;
597 mark_inode_dirty(inode
);
612 reiserfs_xattr_get(const struct inode
*inode
, const char *name
, void *buffer
,
619 size_t buffer_pos
= 0;
621 struct inode
*xinode
;
627 /* We can't have xattrs attached to v1 items since they don't have
628 * generation numbers */
629 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
632 fp
= open_xa_file(inode
, name
, FL_READONLY
);
638 xinode
= fp
->f_dentry
->d_inode
;
639 isize
= xinode
->i_size
;
640 REISERFS_I(inode
)->i_flags
|= i_has_xattr_dir
;
642 /* Just return the size needed */
643 if (buffer
== NULL
) {
644 err
= isize
- sizeof(struct reiserfs_xattr_header
);
648 if (buffer_size
< isize
- sizeof(struct reiserfs_xattr_header
)) {
653 while (file_pos
< isize
) {
657 if (isize
- file_pos
> PAGE_CACHE_SIZE
)
658 chunk
= PAGE_CACHE_SIZE
;
660 chunk
= isize
- file_pos
;
662 page
= reiserfs_get_page(xinode
, file_pos
>> PAGE_CACHE_SHIFT
);
669 data
= page_address(page
);
671 struct reiserfs_xattr_header
*rxh
=
672 (struct reiserfs_xattr_header
*)data
;
673 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
675 /* Magic doesn't match up.. */
676 if (rxh
->h_magic
!= cpu_to_le32(REISERFS_XATTR_MAGIC
)) {
678 reiserfs_put_page(page
);
679 reiserfs_warning(inode
->i_sb
,
680 "Invalid magic for xattr (%s) "
681 "associated with %k", name
,
686 hash
= le32_to_cpu(rxh
->h_hash
);
688 memcpy(buffer
+ buffer_pos
, data
+ skip
, chunk
);
690 reiserfs_put_page(page
);
695 err
= isize
- sizeof(struct reiserfs_xattr_header
);
697 if (xattr_hash(buffer
, isize
- sizeof(struct reiserfs_xattr_header
)) !=
699 reiserfs_warning(inode
->i_sb
,
700 "Invalid hash for xattr (%s) associated "
701 "with %k", name
, INODE_PKEY(inode
));
713 __reiserfs_xattr_del(struct dentry
*xadir
, const char *name
, int namelen
)
715 struct dentry
*dentry
;
716 struct inode
*dir
= xadir
->d_inode
;
719 dentry
= lookup_one_len(name
, xadir
, namelen
);
720 if (IS_ERR(dentry
)) {
721 err
= PTR_ERR(dentry
);
723 } else if (!dentry
->d_inode
) {
728 /* Skip directories.. */
729 if (S_ISDIR(dentry
->d_inode
->i_mode
))
732 if (!is_reiserfs_priv_object(dentry
->d_inode
)) {
733 reiserfs_warning(dir
->i_sb
, "OID %08x [%.*s/%.*s] doesn't have "
734 "priv flag set [parent is %sset].",
735 le32_to_cpu(INODE_PKEY(dentry
->d_inode
)->
736 k_objectid
), xadir
->d_name
.len
,
737 xadir
->d_name
.name
, namelen
, name
,
738 is_reiserfs_priv_object(xadir
->
745 err
= dir
->i_op
->unlink(dir
, dentry
);
756 int reiserfs_xattr_del(struct inode
*inode
, const char *name
)
761 if (IS_RDONLY(inode
))
764 dir
= open_xa_dir(inode
, FL_READONLY
);
770 err
= __reiserfs_xattr_del(dir
, name
, strlen(name
));
774 inode
->i_ctime
= CURRENT_TIME_SEC
;
775 mark_inode_dirty(inode
);
782 /* The following are side effects of other operations that aren't explicitly
783 * modifying extended attributes. This includes operations such as permissions
784 * or ownership changes, object deletions, etc. */
787 reiserfs_delete_xattrs_filler(void *buf
, const char *name
, int namelen
,
788 loff_t offset
, ino_t ino
, unsigned int d_type
)
790 struct dentry
*xadir
= (struct dentry
*)buf
;
792 return __reiserfs_xattr_del(xadir
, name
, namelen
);
796 /* This is called w/ inode->i_sem downed */
797 int reiserfs_delete_xattrs(struct inode
*inode
)
800 struct dentry
*dir
, *root
;
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
);
815 } else if (!dir
->d_inode
) {
820 fp
= dentry_open(dir
, NULL
, O_RDWR
);
823 /* dentry_open dputs the dentry if it fails */
828 err
= xattr_readdir(fp
, reiserfs_delete_xattrs_filler
, dir
);
834 /* Leftovers besides . and .. -- that's not good. */
835 if (dir
->d_inode
->i_nlink
<= 2) {
836 root
= get_xa_root(inode
->i_sb
);
837 reiserfs_write_lock_xattrs(inode
->i_sb
);
838 err
= vfs_rmdir(root
->d_inode
, dir
);
839 reiserfs_write_unlock_xattrs(inode
->i_sb
);
842 reiserfs_warning(inode
->i_sb
,
843 "Couldn't remove all entries in directory");
852 REISERFS_I(inode
)->i_flags
=
853 REISERFS_I(inode
)->i_flags
& ~i_has_xattr_dir
;
857 struct reiserfs_chown_buf
{
859 struct dentry
*xadir
;
863 /* XXX: If there is a better way to do this, I'd love to hear about it */
865 reiserfs_chown_xattrs_filler(void *buf
, const char *name
, int namelen
,
866 loff_t offset
, ino_t ino
, unsigned int d_type
)
868 struct reiserfs_chown_buf
*chown_buf
= (struct reiserfs_chown_buf
*)buf
;
869 struct dentry
*xafile
, *xadir
= chown_buf
->xadir
;
870 struct iattr
*attrs
= chown_buf
->attrs
;
873 xafile
= lookup_one_len(name
, xadir
, namelen
);
875 return PTR_ERR(xafile
);
876 else if (!xafile
->d_inode
) {
881 if (!S_ISDIR(xafile
->d_inode
->i_mode
))
882 err
= notify_change(xafile
, attrs
);
888 int reiserfs_chown_xattrs(struct inode
*inode
, struct iattr
*attrs
)
893 struct reiserfs_chown_buf buf
;
894 unsigned int ia_valid
= attrs
->ia_valid
;
896 /* Skip out, an xattr has no xattrs associated with it */
897 if (is_reiserfs_priv_object(inode
) ||
898 get_inode_sd_version(inode
) == STAT_DATA_V1
||
899 !reiserfs_xattrs(inode
->i_sb
)) {
902 reiserfs_read_lock_xattrs(inode
->i_sb
);
903 dir
= open_xa_dir(inode
, FL_READONLY
);
904 reiserfs_read_unlock_xattrs(inode
->i_sb
);
906 if (PTR_ERR(dir
) != -ENODATA
)
909 } else if (!dir
->d_inode
) {
914 fp
= dentry_open(dir
, NULL
, O_RDWR
);
917 /* dentry_open dputs the dentry if it fails */
923 attrs
->ia_valid
&= (ATTR_UID
| ATTR_GID
| ATTR_CTIME
);
928 err
= xattr_readdir(fp
, reiserfs_chown_xattrs_filler
, &buf
);
934 err
= notify_change(dir
, attrs
);
941 attrs
->ia_valid
= ia_valid
;
945 /* Actual operations that are exported to VFS-land */
948 * Inode operation getxattr()
949 * Preliminary locking: we down dentry->d_inode->i_sem
952 reiserfs_getxattr(struct dentry
* dentry
, const char *name
, void *buffer
,
955 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
958 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
959 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
962 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
963 reiserfs_read_lock_xattrs(dentry
->d_sb
);
964 err
= xah
->get(dentry
->d_inode
, name
, buffer
, size
);
965 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
966 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
971 * Inode operation setxattr()
973 * dentry->d_inode->i_sem down
976 reiserfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
977 size_t size
, int flags
)
979 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
983 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
984 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
987 if (IS_RDONLY(dentry
->d_inode
))
990 if (IS_IMMUTABLE(dentry
->d_inode
) || IS_APPEND(dentry
->d_inode
))
993 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
994 lock
= !has_xattr_dir(dentry
->d_inode
);
996 reiserfs_write_lock_xattrs(dentry
->d_sb
);
998 reiserfs_read_lock_xattrs(dentry
->d_sb
);
999 err
= xah
->set(dentry
->d_inode
, name
, value
, size
, flags
);
1001 reiserfs_write_unlock_xattrs(dentry
->d_sb
);
1003 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
1004 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
1009 * Inode operation removexattr()
1011 * dentry->d_inode->i_sem down
1013 int reiserfs_removexattr(struct dentry
*dentry
, const char *name
)
1016 struct reiserfs_xattr_handler
*xah
= find_xattr_handler_prefix(name
);
1018 if (!xah
|| !reiserfs_xattrs(dentry
->d_sb
) ||
1019 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
1022 if (IS_RDONLY(dentry
->d_inode
))
1025 if (IS_IMMUTABLE(dentry
->d_inode
) || IS_APPEND(dentry
->d_inode
))
1028 reiserfs_write_lock_xattr_i(dentry
->d_inode
);
1029 reiserfs_read_lock_xattrs(dentry
->d_sb
);
1031 /* Deletion pre-operation */
1033 err
= xah
->del(dentry
->d_inode
, name
);
1038 err
= reiserfs_xattr_del(dentry
->d_inode
, name
);
1040 dentry
->d_inode
->i_ctime
= CURRENT_TIME_SEC
;
1041 mark_inode_dirty(dentry
->d_inode
);
1044 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
1045 reiserfs_write_unlock_xattr_i(dentry
->d_inode
);
1049 /* This is what filldir will use:
1050 * r_pos will always contain the amount of space required for the entire
1051 * list. If r_pos becomes larger than r_size, we need more space and we
1052 * return an error indicating this. If r_pos is less than r_size, then we've
1053 * filled the buffer successfully and we return success */
1054 struct reiserfs_listxattr_buf
{
1058 struct inode
*r_inode
;
1062 reiserfs_listxattr_filler(void *buf
, const char *name
, int namelen
,
1063 loff_t offset
, ino_t ino
, unsigned int d_type
)
1065 struct reiserfs_listxattr_buf
*b
= (struct reiserfs_listxattr_buf
*)buf
;
1068 || (namelen
!= 1 && (name
[1] != '.' || namelen
!= 2))) {
1069 struct reiserfs_xattr_handler
*xah
=
1070 find_xattr_handler_prefix(name
);
1072 return 0; /* Unsupported xattr name, skip it */
1074 /* We call ->list() twice because the operation isn't required to just
1075 * return the name back - we want to make sure we have enough space */
1076 len
+= xah
->list(b
->r_inode
, name
, namelen
, NULL
);
1079 if (b
->r_pos
+ len
+ 1 <= b
->r_size
) {
1080 char *p
= b
->r_buf
+ b
->r_pos
;
1081 p
+= xah
->list(b
->r_inode
, name
, namelen
, p
);
1084 b
->r_pos
+= len
+ 1;
1092 * Inode operation listxattr()
1094 * Preliminary locking: we down dentry->d_inode->i_sem
1096 ssize_t
reiserfs_listxattr(struct dentry
* dentry
, char *buffer
, size_t size
)
1101 struct reiserfs_listxattr_buf buf
;
1103 if (!dentry
->d_inode
)
1106 if (!reiserfs_xattrs(dentry
->d_sb
) ||
1107 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
1110 reiserfs_read_lock_xattr_i(dentry
->d_inode
);
1111 reiserfs_read_lock_xattrs(dentry
->d_sb
);
1112 dir
= open_xa_dir(dentry
->d_inode
, FL_READONLY
);
1113 reiserfs_read_unlock_xattrs(dentry
->d_sb
);
1116 if (err
== -ENODATA
)
1117 err
= 0; /* Not an error if there aren't any xattrs */
1121 fp
= dentry_open(dir
, NULL
, O_RDWR
);
1124 /* dentry_open dputs the dentry if it fails */
1129 buf
.r_size
= buffer
? size
: 0;
1131 buf
.r_inode
= dentry
->d_inode
;
1133 REISERFS_I(dentry
->d_inode
)->i_flags
|= i_has_xattr_dir
;
1135 err
= xattr_readdir(fp
, reiserfs_listxattr_filler
, &buf
);
1139 if (buf
.r_pos
> buf
.r_size
&& buffer
!= NULL
)
1148 reiserfs_read_unlock_xattr_i(dentry
->d_inode
);
1152 /* This is the implementation for the xattr plugin infrastructure */
1153 static struct list_head xattr_handlers
= LIST_HEAD_INIT(xattr_handlers
);
1154 static DEFINE_RWLOCK(handler_lock
);
1156 static struct reiserfs_xattr_handler
*find_xattr_handler_prefix(const char
1159 struct reiserfs_xattr_handler
*xah
= NULL
;
1160 struct list_head
*p
;
1162 read_lock(&handler_lock
);
1163 list_for_each(p
, &xattr_handlers
) {
1164 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1165 if (strncmp(xah
->prefix
, prefix
, strlen(xah
->prefix
)) == 0)
1170 read_unlock(&handler_lock
);
1174 static void __unregister_handlers(void)
1176 struct reiserfs_xattr_handler
*xah
;
1177 struct list_head
*p
, *tmp
;
1179 list_for_each_safe(p
, tmp
, &xattr_handlers
) {
1180 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1186 INIT_LIST_HEAD(&xattr_handlers
);
1189 int __init
reiserfs_xattr_register_handlers(void)
1192 struct reiserfs_xattr_handler
*xah
;
1193 struct list_head
*p
;
1195 write_lock(&handler_lock
);
1197 /* If we're already initialized, nothing to do */
1198 if (!list_empty(&xattr_handlers
)) {
1199 write_unlock(&handler_lock
);
1203 /* Add the handlers */
1204 list_add_tail(&user_handler
.handlers
, &xattr_handlers
);
1205 list_add_tail(&trusted_handler
.handlers
, &xattr_handlers
);
1206 #ifdef CONFIG_REISERFS_FS_SECURITY
1207 list_add_tail(&security_handler
.handlers
, &xattr_handlers
);
1209 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1210 list_add_tail(&posix_acl_access_handler
.handlers
, &xattr_handlers
);
1211 list_add_tail(&posix_acl_default_handler
.handlers
, &xattr_handlers
);
1214 /* Run initializers, if available */
1215 list_for_each(p
, &xattr_handlers
) {
1216 xah
= list_entry(p
, struct reiserfs_xattr_handler
, handlers
);
1226 /* Clean up other handlers, if any failed */
1228 __unregister_handlers();
1230 write_unlock(&handler_lock
);
1234 void reiserfs_xattr_unregister_handlers(void)
1236 write_lock(&handler_lock
);
1237 __unregister_handlers();
1238 write_unlock(&handler_lock
);
1241 /* This will catch lookups from the fs root to .reiserfs_priv */
1243 xattr_lookup_poison(struct dentry
*dentry
, struct qstr
*q1
, struct qstr
*name
)
1245 struct dentry
*priv_root
= REISERFS_SB(dentry
->d_sb
)->priv_root
;
1246 if (name
->len
== priv_root
->d_name
.len
&&
1247 name
->hash
== priv_root
->d_name
.hash
&&
1248 !memcmp(name
->name
, priv_root
->d_name
.name
, name
->len
)) {
1250 } else if (q1
->len
== name
->len
&&
1251 !memcmp(q1
->name
, name
->name
, name
->len
))
1256 static struct dentry_operations xattr_lookup_poison_ops
= {
1257 .d_compare
= xattr_lookup_poison
,
1260 /* We need to take a copy of the mount flags since things like
1261 * MS_RDONLY don't get set until *after* we're called.
1262 * mount_flags != mount_options */
1263 int reiserfs_xattr_init(struct super_block
*s
, int mount_flags
)
1267 /* We need generation numbers to ensure that the oid mapping is correct
1268 * v3.5 filesystems don't have them. */
1269 if (!old_format_only(s
)) {
1270 set_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1271 } else if (reiserfs_xattrs_optional(s
)) {
1272 /* Old format filesystem, but optional xattrs have been enabled
1273 * at mount time. Error out. */
1274 reiserfs_warning(s
, "xattrs/ACLs not supported on pre v3.6 "
1275 "format filesystem. Failing mount.");
1279 /* Old format filesystem, but no optional xattrs have been enabled. This
1280 * means we silently disable xattrs on the filesystem. */
1281 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1284 /* If we don't have the privroot located yet - go find it */
1285 if (reiserfs_xattrs(s
) && !REISERFS_SB(s
)->priv_root
) {
1286 struct dentry
*dentry
;
1287 dentry
= lookup_one_len(PRIVROOT_NAME
, s
->s_root
,
1288 strlen(PRIVROOT_NAME
));
1289 if (!IS_ERR(dentry
)) {
1290 if (!(mount_flags
& MS_RDONLY
) && !dentry
->d_inode
) {
1291 struct inode
*inode
= dentry
->d_parent
->d_inode
;
1292 down(&inode
->i_sem
);
1293 err
= inode
->i_op
->mkdir(inode
, dentry
, 0700);
1300 if (dentry
&& dentry
->d_inode
)
1302 "Created %s on %s - reserved for "
1307 } else if (!dentry
->d_inode
) {
1312 err
= PTR_ERR(dentry
);
1314 if (!err
&& dentry
) {
1315 s
->s_root
->d_op
= &xattr_lookup_poison_ops
;
1316 reiserfs_mark_inode_private(dentry
->d_inode
);
1317 REISERFS_SB(s
)->priv_root
= dentry
;
1318 } else if (!(mount_flags
& MS_RDONLY
)) { /* xattrs are unavailable */
1319 /* If we're read-only it just means that the dir hasn't been
1320 * created. Not an error -- just no xattrs on the fs. We'll
1321 * check again if we go read-write */
1322 reiserfs_warning(s
, "xattrs/ACLs enabled and couldn't "
1323 "find/create .reiserfs_priv. Failing mount.");
1329 /* This is only nonzero if there was an error initializing the xattr
1330 * directory or if there is a condition where we don't support them. */
1332 clear_bit(REISERFS_XATTRS
, &(REISERFS_SB(s
)->s_mount_opt
));
1333 clear_bit(REISERFS_XATTRS_USER
, &(REISERFS_SB(s
)->s_mount_opt
));
1334 clear_bit(REISERFS_POSIXACL
, &(REISERFS_SB(s
)->s_mount_opt
));
1337 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1338 s
->s_flags
= s
->s_flags
& ~MS_POSIXACL
;
1339 if (reiserfs_posixacl(s
))
1340 s
->s_flags
|= MS_POSIXACL
;
1346 __reiserfs_permission(struct inode
*inode
, int mask
, struct nameidata
*nd
,
1349 umode_t mode
= inode
->i_mode
;
1351 if (mask
& MAY_WRITE
) {
1353 * Nobody gets write access to a read-only fs.
1355 if (IS_RDONLY(inode
) &&
1356 (S_ISREG(mode
) || S_ISDIR(mode
) || S_ISLNK(mode
)))
1360 * Nobody gets write access to an immutable file.
1362 if (IS_IMMUTABLE(inode
))
1366 /* We don't do permission checks on the internal objects.
1367 * Permissions are determined by the "owning" object. */
1368 if (is_reiserfs_priv_object(inode
))
1371 if (current
->fsuid
== inode
->i_uid
) {
1373 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1374 } else if (reiserfs_posixacl(inode
->i_sb
) &&
1375 get_inode_sd_version(inode
) != STAT_DATA_V1
) {
1376 struct posix_acl
*acl
;
1378 /* ACL can't contain additional permissions if
1379 the ACL_MASK entry is 0 */
1380 if (!(mode
& S_IRWXG
))
1384 reiserfs_read_lock_xattr_i(inode
);
1385 reiserfs_read_lock_xattrs(inode
->i_sb
);
1387 acl
= reiserfs_get_acl(inode
, ACL_TYPE_ACCESS
);
1389 reiserfs_read_unlock_xattrs(inode
->i_sb
);
1390 reiserfs_read_unlock_xattr_i(inode
);
1393 if (PTR_ERR(acl
) == -ENODATA
)
1395 return PTR_ERR(acl
);
1399 int err
= posix_acl_permission(inode
, acl
, mask
);
1400 posix_acl_release(acl
);
1401 if (err
== -EACCES
) {
1402 goto check_capabilities
;
1411 if (in_group_p(inode
->i_gid
))
1416 * If the DACs are ok we don't need any capability check.
1418 if (((mode
& mask
& (MAY_READ
| MAY_WRITE
| MAY_EXEC
)) == mask
))
1423 * Read/write DACs are always overridable.
1424 * Executable DACs are overridable if at least one exec bit is set.
1426 if (!(mask
& MAY_EXEC
) ||
1427 (inode
->i_mode
& S_IXUGO
) || S_ISDIR(inode
->i_mode
))
1428 if (capable(CAP_DAC_OVERRIDE
))
1432 * Searching includes executable on directories, else just read.
1434 if (mask
== MAY_READ
|| (S_ISDIR(inode
->i_mode
) && !(mask
& MAY_WRITE
)))
1435 if (capable(CAP_DAC_READ_SEARCH
))
1441 int reiserfs_permission(struct inode
*inode
, int mask
, struct nameidata
*nd
)
1443 return __reiserfs_permission(inode
, mask
, nd
, 1);
1447 reiserfs_permission_locked(struct inode
*inode
, int mask
, struct nameidata
*nd
)
1449 return __reiserfs_permission(inode
, mask
, nd
, 0);