2 * linux/fs/reiserfs/xattr.c
4 * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
9 * In order to implement EA/ACLs in a clean, backwards compatible manner,
10 * they are implemented as files in a "private" directory.
11 * Each EA is in it's own file, with the directory layout like so (/ is assumed
12 * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
13 * directories named using the capital-hex form of the objectid and
14 * generation number are used. Inside each directory are individual files
15 * named with the name of the extended attribute.
17 * So, for objectid 12648430, we could have:
18 * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
19 * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
20 * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
23 * The file contents are the text of the EA. The size is known based on the
24 * stat data describing the file.
26 * In the case of system.posix_acl_access and system.posix_acl_default, since
27 * these are special cases for filesystem ACLs, they are interpreted by the
28 * kernel, in addition, they are negatively and positively cached and attached
29 * to the inode so that unnecessary lookups are avoided.
32 #include <linux/reiserfs_fs.h>
33 #include <linux/capability.h>
34 #include <linux/dcache.h>
35 #include <linux/namei.h>
36 #include <linux/errno.h>
38 #include <linux/file.h>
39 #include <linux/pagemap.h>
40 #include <linux/xattr.h>
41 #include <linux/reiserfs_xattr.h>
42 #include <linux/reiserfs_acl.h>
43 #include <asm/uaccess.h>
44 #include <net/checksum.h>
45 #include <linux/smp_lock.h>
46 #include <linux/stat.h>
47 #include <asm/semaphore.h>
49 #define FL_READONLY 128
50 #define FL_DIR_SEM_HELD 256
51 #define PRIVROOT_NAME ".reiserfs_priv"
52 #define XAROOT_NAME "xattrs"
54 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
57 /* Returns the dentry referring to the root of the extended attribute
58 * directory tree. If it has already been retrieved, it is used. If it
59 * hasn't been created and the flags indicate creation is allowed, we
60 * attempt to create it. On error, we return a pointer-encoded error.
62 static struct dentry *get_xa_root(struct super_block *sb, int flags)
64 struct dentry *privroot = dget(REISERFS_SB(sb)->priv_root);
65 struct dentry *xaroot;
67 /* This needs to be created at mount-time */
69 return ERR_PTR(-ENODATA);
71 mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
72 if (REISERFS_SB(sb)->xattr_root) {
73 xaroot = dget(REISERFS_SB(sb)->xattr_root);
77 xaroot = lookup_one_len(XAROOT_NAME, privroot, strlen(XAROOT_NAME));
80 } else if (!xaroot->d_inode) {
82 if (flags == 0 || flags & XATTR_CREATE)
83 err = privroot->d_inode->i_op->mkdir(privroot->d_inode,
87 xaroot = ERR_PTR(err);
91 REISERFS_SB(sb)->xattr_root = dget(xaroot);
94 mutex_unlock(&privroot->d_inode->i_mutex);
99 /* Opens the directory corresponding to the inode's extended attribute store.
100 * If flags allow, the tree to the directory may be created. If creation is
101 * prohibited, -ENODATA is returned. */
102 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
104 struct dentry *xaroot, *xadir;
107 xaroot = get_xa_root(inode->i_sb, flags);
111 /* ok, we have xaroot open */
112 snprintf(namebuf, sizeof(namebuf), "%X.%X",
113 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
114 inode->i_generation);
115 xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
121 if (!xadir->d_inode) {
123 if (flags == 0 || flags & XATTR_CREATE) {
124 /* Although there is nothing else trying to create this directory,
125 * another directory with the same hash may be created, so we need
126 * to protect against that */
128 xaroot->d_inode->i_op->mkdir(xaroot->d_inode, xadir,
136 if (!xadir->d_inode) {
139 return ERR_PTR(-ENODATA);
147 /* Returns a dentry corresponding to a specific extended attribute file
148 * for the inode. If flags allow, the file is created. Otherwise, a
149 * valid or negative dentry, or an error is returned. */
150 static struct dentry *get_xa_file_dentry(const struct inode *inode,
151 const char *name, int flags)
153 struct dentry *xadir, *xafile;
156 xadir = open_xa_dir(inode, flags);
158 return ERR_PTR(PTR_ERR(xadir));
159 } else if (xadir && !xadir->d_inode) {
161 return ERR_PTR(-ENODATA);
164 xafile = lookup_one_len(name, xadir, strlen(name));
165 if (IS_ERR(xafile)) {
167 return ERR_PTR(PTR_ERR(xafile));
170 if (xafile->d_inode) { /* file exists */
171 if (flags & XATTR_CREATE) {
176 } else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
179 /* inode->i_mutex is down, so nothing else can try to create
181 err = xadir->d_inode->i_op->create(xadir->d_inode, xafile,
182 0700 | S_IFREG, NULL);
193 xafile = ERR_PTR(err);
197 /* Opens a file pointer to the attribute associated with inode */
198 static struct file *open_xa_file(const struct inode *inode, const char *name,
201 struct dentry *xafile;
204 xafile = get_xa_file_dentry(inode, name, flags);
206 return ERR_PTR(PTR_ERR(xafile));
207 else if (!xafile->d_inode) {
209 return ERR_PTR(-ENODATA);
212 fp = dentry_open(xafile, NULL, O_RDWR);
213 /* dentry_open dputs the dentry if it fails */
219 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
220 * we need to drop the path before calling the filldir struct. That
221 * would be a big performance hit to the non-xattr case, so I've copied
222 * the whole thing for now. --clm
224 * the big difference is that I go backwards through the directory,
225 * and don't mess with f->f_pos, but the idea is the same. Do some
226 * action on each and every entry in the directory.
228 * we're called with i_mutex held, so there are no worries about the directory
229 * changing underneath us.
231 static int __xattr_readdir(struct file *filp, void *dirent, filldir_t filldir)
233 struct inode *inode = filp->f_path.dentry->d_inode;
234 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
235 INITIALIZE_PATH(path_to_entry);
236 struct buffer_head *bh;
238 struct item_head *ih, tmp_ih;
242 char small_buf[32]; /* avoid kmalloc if we can */
243 struct reiserfs_de_head *deh;
248 struct reiserfs_dir_entry de;
250 /* form key for search the next directory entry using f_pos field of
252 next_pos = max_reiserfs_offset(inode);
256 if (next_pos <= DOT_DOT_OFFSET)
258 make_cpu_key(&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
261 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
263 if (search_res == IO_ERROR) {
264 // FIXME: we could just skip part of directory which could
266 pathrelse(&path_to_entry);
270 if (search_res == NAME_NOT_FOUND)
273 set_de_name_and_namelen(&de);
274 entry_num = de.de_entry_num;
275 deh = &(de.de_deh[entry_num]);
280 if (!is_direntry_le_ih(ih)) {
281 reiserfs_warning(inode->i_sb, "not direntry %h", ih);
284 copy_item_head(&tmp_ih, ih);
286 /* we must have found item, that is item of this directory, */
287 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
288 "vs-9000: found item %h does not match to dir we readdir %K",
291 if (deh_offset(deh) <= DOT_DOT_OFFSET) {
295 /* look for the previous entry in the directory */
296 next_pos = deh_offset(deh) - 1;
298 if (!de_visible(deh))
299 /* it is hidden entry */
302 d_reclen = entry_length(bh, ih, entry_num);
303 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
304 d_off = deh_offset(deh);
305 d_ino = deh_objectid(deh);
307 if (!d_name[d_reclen - 1])
308 d_reclen = strlen(d_name);
310 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)) {
311 /* too big to send back to VFS */
315 /* Ignore the .reiserfs_priv entry */
316 if (reiserfs_xattrs(inode->i_sb) &&
317 !old_format_only(inode->i_sb) &&
319 le32_to_cpu(INODE_PKEY
320 (REISERFS_SB(inode->i_sb)->priv_root->d_inode)->
324 if (d_reclen <= 32) {
325 local_buf = small_buf;
327 local_buf = kmalloc(d_reclen, GFP_NOFS);
329 pathrelse(&path_to_entry);
332 if (item_moved(&tmp_ih, &path_to_entry)) {
335 /* sigh, must retry. Do this same offset again */
341 // Note, that we copy name to user space via temporary
342 // buffer (local_buf) because filldir will block if
343 // user space buffer is swapped out. At that time
344 // entry can move to somewhere else
345 memcpy(local_buf, d_name, d_reclen);
347 /* the filldir function might need to start transactions,
348 * or do who knows what. Release the path now that we've
349 * copied all the important stuff out of the deh
351 pathrelse(&path_to_entry);
353 if (filldir(dirent, local_buf, d_reclen, d_off, d_ino,
355 if (local_buf != small_buf) {
360 if (local_buf != small_buf) {
366 pathrelse(&path_to_entry);
371 * this could be done with dedicated readdir ops for the xattr files,
372 * but I want to get something working asap
373 * this is stolen from vfs_readdir
377 int xattr_readdir(struct file *file, filldir_t filler, void *buf)
379 struct inode *inode = file->f_path.dentry->d_inode;
381 if (!file->f_op || !file->f_op->readdir)
383 mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
384 // down(&inode->i_zombie);
386 if (!IS_DEADDIR(inode)) {
388 res = __xattr_readdir(file, buf, filler);
391 // up(&inode->i_zombie);
392 mutex_unlock(&inode->i_mutex);
397 /* Internal operations on file data */
398 static inline void reiserfs_put_page(struct page *page)
401 page_cache_release(page);
404 static struct page *reiserfs_get_page(struct inode *dir, unsigned long n)
406 struct address_space *mapping = dir->i_mapping;
408 /* We can deadlock if we try to free dentries,
409 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
410 mapping_set_gfp_mask(mapping, GFP_NOFS);
411 page = read_mapping_page(mapping, n, NULL);
420 reiserfs_put_page(page);
421 return ERR_PTR(-EIO);
424 static inline __u32 xattr_hash(const char *msg, int len)
426 return csum_partial(msg, len, 0);
429 /* Generic extended attribute operations that can be used by xa plugins */
432 * inode->i_mutex: down
435 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
436 size_t buffer_size, int flags)
442 struct address_space *mapping;
444 size_t buffer_pos = 0;
445 struct inode *xinode;
446 struct iattr newattrs;
449 if (get_inode_sd_version(inode) == STAT_DATA_V1)
452 /* Empty xattrs are ok, they're just empty files, no hash */
453 if (buffer && buffer_size)
454 xahash = xattr_hash(buffer, buffer_size);
457 fp = open_xa_file(inode, name, flags);
463 xinode = fp->f_path.dentry->d_inode;
464 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
466 /* we need to copy it off.. */
467 if (xinode->i_nlink > 1) {
469 err = reiserfs_xattr_del(inode, name);
472 /* We just killed the old one, we're not replacing anymore */
473 if (flags & XATTR_REPLACE)
474 flags &= ~XATTR_REPLACE;
478 /* Resize it so we're ok to write there */
479 newattrs.ia_size = buffer_size;
480 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
481 mutex_lock(&xinode->i_mutex);
482 err = notify_change(fp->f_path.dentry, &newattrs);
486 mapping = xinode->i_mapping;
487 while (buffer_pos < buffer_size || buffer_pos == 0) {
490 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
491 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
492 chunk = PAGE_CACHE_SIZE;
494 chunk = buffer_size - buffer_pos;
496 page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
503 data = page_address(page);
506 struct reiserfs_xattr_header *rxh;
507 skip = file_pos = sizeof(struct reiserfs_xattr_header);
508 if (chunk + skip > PAGE_CACHE_SIZE)
509 chunk = PAGE_CACHE_SIZE - skip;
510 rxh = (struct reiserfs_xattr_header *)data;
511 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
512 rxh->h_hash = cpu_to_le32(xahash);
515 err = mapping->a_ops->prepare_write(fp, page, page_offset,
516 page_offset + chunk + skip);
519 memcpy(data + skip, buffer + buffer_pos, chunk);
521 mapping->a_ops->commit_write(fp, page, page_offset,
522 page_offset + chunk +
526 reiserfs_put_page(page);
530 if (err || buffer_size == 0 || !buffer)
534 /* We can't mark the inode dirty if it's not hashed. This is the case
535 * when we're inheriting the default ACL. If we dirty it, the inode
536 * gets marked dirty, but won't (ever) make it onto the dirty list until
537 * it's synced explicitly to clear I_DIRTY. This is bad. */
538 if (!hlist_unhashed(&inode->i_hash)) {
539 inode->i_ctime = CURRENT_TIME_SEC;
540 mark_inode_dirty(inode);
544 mutex_unlock(&xinode->i_mutex);
552 * inode->i_mutex: down
555 reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
562 size_t buffer_pos = 0;
564 struct inode *xinode;
570 /* We can't have xattrs attached to v1 items since they don't have
571 * generation numbers */
572 if (get_inode_sd_version(inode) == STAT_DATA_V1)
575 fp = open_xa_file(inode, name, FL_READONLY);
581 xinode = fp->f_path.dentry->d_inode;
582 isize = xinode->i_size;
583 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
585 /* Just return the size needed */
586 if (buffer == NULL) {
587 err = isize - sizeof(struct reiserfs_xattr_header);
591 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
596 while (file_pos < isize) {
600 if (isize - file_pos > PAGE_CACHE_SIZE)
601 chunk = PAGE_CACHE_SIZE;
603 chunk = isize - file_pos;
605 page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
612 data = page_address(page);
614 struct reiserfs_xattr_header *rxh =
615 (struct reiserfs_xattr_header *)data;
616 skip = file_pos = sizeof(struct reiserfs_xattr_header);
618 /* Magic doesn't match up.. */
619 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
621 reiserfs_put_page(page);
622 reiserfs_warning(inode->i_sb,
623 "Invalid magic for xattr (%s) "
624 "associated with %k", name,
629 hash = le32_to_cpu(rxh->h_hash);
631 memcpy(buffer + buffer_pos, data + skip, chunk);
633 reiserfs_put_page(page);
638 err = isize - sizeof(struct reiserfs_xattr_header);
640 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
642 reiserfs_warning(inode->i_sb,
643 "Invalid hash for xattr (%s) associated "
644 "with %k", name, INODE_PKEY(inode));
656 __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
658 struct dentry *dentry;
659 struct inode *dir = xadir->d_inode;
662 dentry = lookup_one_len(name, xadir, namelen);
663 if (IS_ERR(dentry)) {
664 err = PTR_ERR(dentry);
666 } else if (!dentry->d_inode) {
671 /* Skip directories.. */
672 if (S_ISDIR(dentry->d_inode->i_mode))
675 if (!is_reiserfs_priv_object(dentry->d_inode)) {
676 reiserfs_warning(dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
677 "priv flag set [parent is %sset].",
678 le32_to_cpu(INODE_PKEY(dentry->d_inode)->
679 k_objectid), xadir->d_name.len,
680 xadir->d_name.name, namelen, name,
681 is_reiserfs_priv_object(xadir->
688 err = dir->i_op->unlink(dir, dentry);
699 int reiserfs_xattr_del(struct inode *inode, const char *name)
704 dir = open_xa_dir(inode, FL_READONLY);
710 err = __reiserfs_xattr_del(dir, name, strlen(name));
714 inode->i_ctime = CURRENT_TIME_SEC;
715 mark_inode_dirty(inode);
722 /* The following are side effects of other operations that aren't explicitly
723 * modifying extended attributes. This includes operations such as permissions
724 * or ownership changes, object deletions, etc. */
727 reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
728 loff_t offset, u64 ino, unsigned int d_type)
730 struct dentry *xadir = (struct dentry *)buf;
732 return __reiserfs_xattr_del(xadir, name, namelen);
736 /* This is called w/ inode->i_mutex downed */
737 int reiserfs_delete_xattrs(struct inode *inode)
740 struct dentry *dir, *root;
743 /* Skip out, an xattr has no xattrs associated with it */
744 if (is_reiserfs_priv_object(inode) ||
745 get_inode_sd_version(inode) == STAT_DATA_V1 ||
746 !reiserfs_xattrs(inode->i_sb)) {
749 reiserfs_read_lock_xattrs(inode->i_sb);
750 dir = open_xa_dir(inode, FL_READONLY);
751 reiserfs_read_unlock_xattrs(inode->i_sb);
755 } else if (!dir->d_inode) {
760 fp = dentry_open(dir, NULL, O_RDWR);
763 /* dentry_open dputs the dentry if it fails */
768 err = xattr_readdir(fp, reiserfs_delete_xattrs_filler, dir);
774 /* Leftovers besides . and .. -- that's not good. */
775 if (dir->d_inode->i_nlink <= 2) {
776 root = get_xa_root(inode->i_sb, XATTR_REPLACE);
777 reiserfs_write_lock_xattrs(inode->i_sb);
778 err = vfs_rmdir(root->d_inode, dir);
779 reiserfs_write_unlock_xattrs(inode->i_sb);
782 reiserfs_warning(inode->i_sb,
783 "Couldn't remove all entries in directory");
792 REISERFS_I(inode)->i_flags =
793 REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
797 struct reiserfs_chown_buf {
799 struct dentry *xadir;
803 /* XXX: If there is a better way to do this, I'd love to hear about it */
805 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
806 loff_t offset, u64 ino, unsigned int d_type)
808 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
809 struct dentry *xafile, *xadir = chown_buf->xadir;
810 struct iattr *attrs = chown_buf->attrs;
813 xafile = lookup_one_len(name, xadir, namelen);
815 return PTR_ERR(xafile);
816 else if (!xafile->d_inode) {
821 if (!S_ISDIR(xafile->d_inode->i_mode))
822 err = notify_change(xafile, attrs);
828 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
833 struct reiserfs_chown_buf buf;
834 unsigned int ia_valid = attrs->ia_valid;
836 /* Skip out, an xattr has no xattrs associated with it */
837 if (is_reiserfs_priv_object(inode) ||
838 get_inode_sd_version(inode) == STAT_DATA_V1 ||
839 !reiserfs_xattrs(inode->i_sb)) {
842 reiserfs_read_lock_xattrs(inode->i_sb);
843 dir = open_xa_dir(inode, FL_READONLY);
844 reiserfs_read_unlock_xattrs(inode->i_sb);
846 if (PTR_ERR(dir) != -ENODATA)
849 } else if (!dir->d_inode) {
854 fp = dentry_open(dir, NULL, O_RDWR);
857 /* dentry_open dputs the dentry if it fails */
863 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
868 err = xattr_readdir(fp, reiserfs_chown_xattrs_filler, &buf);
874 err = notify_change(dir, attrs);
881 attrs->ia_valid = ia_valid;
885 /* Actual operations that are exported to VFS-land */
888 * Inode operation getxattr()
889 * Preliminary locking: we down dentry->d_inode->i_mutex
892 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
895 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
898 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
899 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
902 reiserfs_read_lock_xattr_i(dentry->d_inode);
903 reiserfs_read_lock_xattrs(dentry->d_sb);
904 err = xah->get(dentry->d_inode, name, buffer, size);
905 reiserfs_read_unlock_xattrs(dentry->d_sb);
906 reiserfs_read_unlock_xattr_i(dentry->d_inode);
911 * Inode operation setxattr()
913 * dentry->d_inode->i_mutex down
916 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
917 size_t size, int flags)
919 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
923 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
924 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
927 reiserfs_write_lock_xattr_i(dentry->d_inode);
928 lock = !has_xattr_dir(dentry->d_inode);
930 reiserfs_write_lock_xattrs(dentry->d_sb);
932 reiserfs_read_lock_xattrs(dentry->d_sb);
933 err = xah->set(dentry->d_inode, name, value, size, flags);
935 reiserfs_write_unlock_xattrs(dentry->d_sb);
937 reiserfs_read_unlock_xattrs(dentry->d_sb);
938 reiserfs_write_unlock_xattr_i(dentry->d_inode);
943 * Inode operation removexattr()
945 * dentry->d_inode->i_mutex down
947 int reiserfs_removexattr(struct dentry *dentry, const char *name)
950 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
952 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
953 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
956 reiserfs_write_lock_xattr_i(dentry->d_inode);
957 reiserfs_read_lock_xattrs(dentry->d_sb);
959 /* Deletion pre-operation */
961 err = xah->del(dentry->d_inode, name);
966 err = reiserfs_xattr_del(dentry->d_inode, name);
968 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
969 mark_inode_dirty(dentry->d_inode);
972 reiserfs_read_unlock_xattrs(dentry->d_sb);
973 reiserfs_write_unlock_xattr_i(dentry->d_inode);
977 /* This is what filldir will use:
978 * r_pos will always contain the amount of space required for the entire
979 * list. If r_pos becomes larger than r_size, we need more space and we
980 * return an error indicating this. If r_pos is less than r_size, then we've
981 * filled the buffer successfully and we return success */
982 struct reiserfs_listxattr_buf {
986 struct inode *r_inode;
990 reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
991 loff_t offset, u64 ino, unsigned int d_type)
993 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
996 || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
997 struct reiserfs_xattr_handler *xah =
998 find_xattr_handler_prefix(name);
1000 return 0; /* Unsupported xattr name, skip it */
1002 /* We call ->list() twice because the operation isn't required to just
1003 * return the name back - we want to make sure we have enough space */
1004 len += xah->list(b->r_inode, name, namelen, NULL);
1007 if (b->r_pos + len + 1 <= b->r_size) {
1008 char *p = b->r_buf + b->r_pos;
1009 p += xah->list(b->r_inode, name, namelen, p);
1012 b->r_pos += len + 1;
1020 * Inode operation listxattr()
1022 * Preliminary locking: we down dentry->d_inode->i_mutex
1024 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
1029 struct reiserfs_listxattr_buf buf;
1031 if (!dentry->d_inode)
1034 if (!reiserfs_xattrs(dentry->d_sb) ||
1035 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
1038 reiserfs_read_lock_xattr_i(dentry->d_inode);
1039 reiserfs_read_lock_xattrs(dentry->d_sb);
1040 dir = open_xa_dir(dentry->d_inode, FL_READONLY);
1041 reiserfs_read_unlock_xattrs(dentry->d_sb);
1044 if (err == -ENODATA)
1045 err = 0; /* Not an error if there aren't any xattrs */
1049 fp = dentry_open(dir, NULL, O_RDWR);
1052 /* dentry_open dputs the dentry if it fails */
1057 buf.r_size = buffer ? size : 0;
1059 buf.r_inode = dentry->d_inode;
1061 REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
1063 err = xattr_readdir(fp, reiserfs_listxattr_filler, &buf);
1067 if (buf.r_pos > buf.r_size && buffer != NULL)
1076 reiserfs_read_unlock_xattr_i(dentry->d_inode);
1080 /* This is the implementation for the xattr plugin infrastructure */
1081 static struct list_head xattr_handlers = LIST_HEAD_INIT(xattr_handlers);
1082 static DEFINE_RWLOCK(handler_lock);
1084 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
1087 struct reiserfs_xattr_handler *xah = NULL;
1088 struct list_head *p;
1090 read_lock(&handler_lock);
1091 list_for_each(p, &xattr_handlers) {
1092 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1093 if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
1098 read_unlock(&handler_lock);
1102 static void __unregister_handlers(void)
1104 struct reiserfs_xattr_handler *xah;
1105 struct list_head *p, *tmp;
1107 list_for_each_safe(p, tmp, &xattr_handlers) {
1108 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1114 INIT_LIST_HEAD(&xattr_handlers);
1117 int __init reiserfs_xattr_register_handlers(void)
1120 struct reiserfs_xattr_handler *xah;
1121 struct list_head *p;
1123 write_lock(&handler_lock);
1125 /* If we're already initialized, nothing to do */
1126 if (!list_empty(&xattr_handlers)) {
1127 write_unlock(&handler_lock);
1131 /* Add the handlers */
1132 list_add_tail(&user_handler.handlers, &xattr_handlers);
1133 list_add_tail(&trusted_handler.handlers, &xattr_handlers);
1134 #ifdef CONFIG_REISERFS_FS_SECURITY
1135 list_add_tail(&security_handler.handlers, &xattr_handlers);
1137 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1138 list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
1139 list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
1142 /* Run initializers, if available */
1143 list_for_each(p, &xattr_handlers) {
1144 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1154 /* Clean up other handlers, if any failed */
1156 __unregister_handlers();
1158 write_unlock(&handler_lock);
1162 void reiserfs_xattr_unregister_handlers(void)
1164 write_lock(&handler_lock);
1165 __unregister_handlers();
1166 write_unlock(&handler_lock);
1169 /* This will catch lookups from the fs root to .reiserfs_priv */
1171 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1173 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1174 if (name->len == priv_root->d_name.len &&
1175 name->hash == priv_root->d_name.hash &&
1176 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1178 } else if (q1->len == name->len &&
1179 !memcmp(q1->name, name->name, name->len))
1184 static struct dentry_operations xattr_lookup_poison_ops = {
1185 .d_compare = xattr_lookup_poison,
1188 /* We need to take a copy of the mount flags since things like
1189 * MS_RDONLY don't get set until *after* we're called.
1190 * mount_flags != mount_options */
1191 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1195 /* We need generation numbers to ensure that the oid mapping is correct
1196 * v3.5 filesystems don't have them. */
1197 if (!old_format_only(s)) {
1198 set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1199 } else if (reiserfs_xattrs_optional(s)) {
1200 /* Old format filesystem, but optional xattrs have been enabled
1201 * at mount time. Error out. */
1202 reiserfs_warning(s, "xattrs/ACLs not supported on pre v3.6 "
1203 "format filesystem. Failing mount.");
1207 /* Old format filesystem, but no optional xattrs have been enabled. This
1208 * means we silently disable xattrs on the filesystem. */
1209 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1212 /* If we don't have the privroot located yet - go find it */
1213 if (reiserfs_xattrs(s) && !REISERFS_SB(s)->priv_root) {
1214 struct dentry *dentry;
1215 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1216 strlen(PRIVROOT_NAME));
1217 if (!IS_ERR(dentry)) {
1218 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
1219 struct inode *inode = dentry->d_parent->d_inode;
1220 mutex_lock(&inode->i_mutex);
1221 err = inode->i_op->mkdir(inode, dentry, 0700);
1222 mutex_unlock(&inode->i_mutex);
1228 if (dentry && dentry->d_inode)
1230 "Created %s on %s - reserved for "
1235 } else if (!dentry->d_inode) {
1240 err = PTR_ERR(dentry);
1242 if (!err && dentry) {
1243 s->s_root->d_op = &xattr_lookup_poison_ops;
1244 reiserfs_mark_inode_private(dentry->d_inode);
1245 REISERFS_SB(s)->priv_root = dentry;
1246 } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
1247 /* If we're read-only it just means that the dir hasn't been
1248 * created. Not an error -- just no xattrs on the fs. We'll
1249 * check again if we go read-write */
1250 reiserfs_warning(s, "xattrs/ACLs enabled and couldn't "
1251 "find/create .reiserfs_priv. Failing mount.");
1257 /* This is only nonzero if there was an error initializing the xattr
1258 * directory or if there is a condition where we don't support them. */
1260 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1261 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1262 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1265 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1266 s->s_flags = s->s_flags & ~MS_POSIXACL;
1267 if (reiserfs_posixacl(s))
1268 s->s_flags |= MS_POSIXACL;
1273 static int reiserfs_check_acl(struct inode *inode, int mask)
1275 struct posix_acl *acl;
1276 int error = -EAGAIN; /* do regular unix permission checks by default */
1278 reiserfs_read_lock_xattr_i(inode);
1279 reiserfs_read_lock_xattrs(inode->i_sb);
1281 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1283 reiserfs_read_unlock_xattrs(inode->i_sb);
1284 reiserfs_read_unlock_xattr_i(inode);
1288 error = posix_acl_permission(inode, acl, mask);
1289 posix_acl_release(acl);
1290 } else if (PTR_ERR(acl) != -ENODATA)
1291 error = PTR_ERR(acl);
1297 int reiserfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1300 * We don't do permission checks on the internal objects.
1301 * Permissions are determined by the "owning" object.
1303 if (is_reiserfs_priv_object(inode))
1307 * Stat data v1 doesn't support ACLs.
1309 if (get_inode_sd_version(inode) == STAT_DATA_V1)
1310 return generic_permission(inode, mask, NULL);
1312 return generic_permission(inode, mask, reiserfs_check_acl);