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);