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_CAST(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_CAST(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 int reiserfs_commit_write(struct file *f, struct page *page,
430 unsigned from, unsigned to);
431 int reiserfs_prepare_write(struct file *f, struct page *page,
432 unsigned from, unsigned to);
435 /* Generic extended attribute operations that can be used by xa plugins */
438 * inode->i_mutex: down
441 reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
442 size_t buffer_size, int flags)
448 struct address_space *mapping;
450 size_t buffer_pos = 0;
451 struct inode *xinode;
452 struct iattr newattrs;
455 if (get_inode_sd_version(inode) == STAT_DATA_V1)
458 /* Empty xattrs are ok, they're just empty files, no hash */
459 if (buffer && buffer_size)
460 xahash = xattr_hash(buffer, buffer_size);
463 fp = open_xa_file(inode, name, flags);
469 xinode = fp->f_path.dentry->d_inode;
470 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
472 /* we need to copy it off.. */
473 if (xinode->i_nlink > 1) {
475 err = reiserfs_xattr_del(inode, name);
478 /* We just killed the old one, we're not replacing anymore */
479 if (flags & XATTR_REPLACE)
480 flags &= ~XATTR_REPLACE;
484 /* Resize it so we're ok to write there */
485 newattrs.ia_size = buffer_size;
486 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
487 mutex_lock_nested(&xinode->i_mutex, I_MUTEX_XATTR);
488 err = notify_change(fp->f_path.dentry, &newattrs);
492 mapping = xinode->i_mapping;
493 while (buffer_pos < buffer_size || buffer_pos == 0) {
496 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
497 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
498 chunk = PAGE_CACHE_SIZE;
500 chunk = buffer_size - buffer_pos;
502 page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
509 data = page_address(page);
512 struct reiserfs_xattr_header *rxh;
513 skip = file_pos = sizeof(struct reiserfs_xattr_header);
514 if (chunk + skip > PAGE_CACHE_SIZE)
515 chunk = PAGE_CACHE_SIZE - skip;
516 rxh = (struct reiserfs_xattr_header *)data;
517 rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
518 rxh->h_hash = cpu_to_le32(xahash);
521 err = reiserfs_prepare_write(fp, page, page_offset,
522 page_offset + chunk + skip);
525 memcpy(data + skip, buffer + buffer_pos, chunk);
527 reiserfs_commit_write(fp, page, page_offset,
528 page_offset + chunk +
532 reiserfs_put_page(page);
536 if (err || buffer_size == 0 || !buffer)
540 /* We can't mark the inode dirty if it's not hashed. This is the case
541 * when we're inheriting the default ACL. If we dirty it, the inode
542 * gets marked dirty, but won't (ever) make it onto the dirty list until
543 * it's synced explicitly to clear I_DIRTY. This is bad. */
544 if (!hlist_unhashed(&inode->i_hash)) {
545 inode->i_ctime = CURRENT_TIME_SEC;
546 mark_inode_dirty(inode);
550 mutex_unlock(&xinode->i_mutex);
558 * inode->i_mutex: down
561 reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
568 size_t buffer_pos = 0;
570 struct inode *xinode;
576 /* We can't have xattrs attached to v1 items since they don't have
577 * generation numbers */
578 if (get_inode_sd_version(inode) == STAT_DATA_V1)
581 fp = open_xa_file(inode, name, FL_READONLY);
587 xinode = fp->f_path.dentry->d_inode;
588 isize = xinode->i_size;
589 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
591 /* Just return the size needed */
592 if (buffer == NULL) {
593 err = isize - sizeof(struct reiserfs_xattr_header);
597 if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
602 while (file_pos < isize) {
606 if (isize - file_pos > PAGE_CACHE_SIZE)
607 chunk = PAGE_CACHE_SIZE;
609 chunk = isize - file_pos;
611 page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
618 data = page_address(page);
620 struct reiserfs_xattr_header *rxh =
621 (struct reiserfs_xattr_header *)data;
622 skip = file_pos = sizeof(struct reiserfs_xattr_header);
624 /* Magic doesn't match up.. */
625 if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
627 reiserfs_put_page(page);
628 reiserfs_warning(inode->i_sb,
629 "Invalid magic for xattr (%s) "
630 "associated with %k", name,
635 hash = le32_to_cpu(rxh->h_hash);
637 memcpy(buffer + buffer_pos, data + skip, chunk);
639 reiserfs_put_page(page);
644 err = isize - sizeof(struct reiserfs_xattr_header);
646 if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
648 reiserfs_warning(inode->i_sb,
649 "Invalid hash for xattr (%s) associated "
650 "with %k", name, INODE_PKEY(inode));
662 __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
664 struct dentry *dentry;
665 struct inode *dir = xadir->d_inode;
668 dentry = lookup_one_len(name, xadir, namelen);
669 if (IS_ERR(dentry)) {
670 err = PTR_ERR(dentry);
672 } else if (!dentry->d_inode) {
677 /* Skip directories.. */
678 if (S_ISDIR(dentry->d_inode->i_mode))
681 if (!is_reiserfs_priv_object(dentry->d_inode)) {
682 reiserfs_warning(dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
683 "priv flag set [parent is %sset].",
684 le32_to_cpu(INODE_PKEY(dentry->d_inode)->
685 k_objectid), xadir->d_name.len,
686 xadir->d_name.name, namelen, name,
687 is_reiserfs_priv_object(xadir->
694 err = dir->i_op->unlink(dir, dentry);
705 int reiserfs_xattr_del(struct inode *inode, const char *name)
710 dir = open_xa_dir(inode, FL_READONLY);
716 err = __reiserfs_xattr_del(dir, name, strlen(name));
720 inode->i_ctime = CURRENT_TIME_SEC;
721 mark_inode_dirty(inode);
728 /* The following are side effects of other operations that aren't explicitly
729 * modifying extended attributes. This includes operations such as permissions
730 * or ownership changes, object deletions, etc. */
733 reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
734 loff_t offset, u64 ino, unsigned int d_type)
736 struct dentry *xadir = (struct dentry *)buf;
738 return __reiserfs_xattr_del(xadir, name, namelen);
742 /* This is called w/ inode->i_mutex downed */
743 int reiserfs_delete_xattrs(struct inode *inode)
746 struct dentry *dir, *root;
749 /* Skip out, an xattr has no xattrs associated with it */
750 if (is_reiserfs_priv_object(inode) ||
751 get_inode_sd_version(inode) == STAT_DATA_V1 ||
752 !reiserfs_xattrs(inode->i_sb)) {
755 reiserfs_read_lock_xattrs(inode->i_sb);
756 dir = open_xa_dir(inode, FL_READONLY);
757 reiserfs_read_unlock_xattrs(inode->i_sb);
761 } else if (!dir->d_inode) {
766 fp = dentry_open(dir, NULL, O_RDWR);
769 /* dentry_open dputs the dentry if it fails */
774 err = xattr_readdir(fp, reiserfs_delete_xattrs_filler, dir);
780 /* Leftovers besides . and .. -- that's not good. */
781 if (dir->d_inode->i_nlink <= 2) {
782 root = get_xa_root(inode->i_sb, XATTR_REPLACE);
783 reiserfs_write_lock_xattrs(inode->i_sb);
784 err = vfs_rmdir(root->d_inode, dir);
785 reiserfs_write_unlock_xattrs(inode->i_sb);
788 reiserfs_warning(inode->i_sb,
789 "Couldn't remove all entries in directory");
798 REISERFS_I(inode)->i_flags =
799 REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
803 struct reiserfs_chown_buf {
805 struct dentry *xadir;
809 /* XXX: If there is a better way to do this, I'd love to hear about it */
811 reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
812 loff_t offset, u64 ino, unsigned int d_type)
814 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
815 struct dentry *xafile, *xadir = chown_buf->xadir;
816 struct iattr *attrs = chown_buf->attrs;
819 xafile = lookup_one_len(name, xadir, namelen);
821 return PTR_ERR(xafile);
822 else if (!xafile->d_inode) {
827 if (!S_ISDIR(xafile->d_inode->i_mode))
828 err = notify_change(xafile, attrs);
834 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
839 struct reiserfs_chown_buf buf;
840 unsigned int ia_valid = attrs->ia_valid;
842 /* Skip out, an xattr has no xattrs associated with it */
843 if (is_reiserfs_priv_object(inode) ||
844 get_inode_sd_version(inode) == STAT_DATA_V1 ||
845 !reiserfs_xattrs(inode->i_sb)) {
848 reiserfs_read_lock_xattrs(inode->i_sb);
849 dir = open_xa_dir(inode, FL_READONLY);
850 reiserfs_read_unlock_xattrs(inode->i_sb);
852 if (PTR_ERR(dir) != -ENODATA)
855 } else if (!dir->d_inode) {
860 fp = dentry_open(dir, NULL, O_RDWR);
863 /* dentry_open dputs the dentry if it fails */
869 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
874 err = xattr_readdir(fp, reiserfs_chown_xattrs_filler, &buf);
880 err = notify_change(dir, attrs);
887 attrs->ia_valid = ia_valid;
891 /* Actual operations that are exported to VFS-land */
894 * Inode operation getxattr()
895 * Preliminary locking: we down dentry->d_inode->i_mutex
898 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
901 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
904 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
905 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
908 reiserfs_read_lock_xattr_i(dentry->d_inode);
909 reiserfs_read_lock_xattrs(dentry->d_sb);
910 err = xah->get(dentry->d_inode, name, buffer, size);
911 reiserfs_read_unlock_xattrs(dentry->d_sb);
912 reiserfs_read_unlock_xattr_i(dentry->d_inode);
917 * Inode operation setxattr()
919 * dentry->d_inode->i_mutex down
922 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
923 size_t size, int flags)
925 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
929 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
930 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
933 reiserfs_write_lock_xattr_i(dentry->d_inode);
934 lock = !has_xattr_dir(dentry->d_inode);
936 reiserfs_write_lock_xattrs(dentry->d_sb);
938 reiserfs_read_lock_xattrs(dentry->d_sb);
939 err = xah->set(dentry->d_inode, name, value, size, flags);
941 reiserfs_write_unlock_xattrs(dentry->d_sb);
943 reiserfs_read_unlock_xattrs(dentry->d_sb);
944 reiserfs_write_unlock_xattr_i(dentry->d_inode);
949 * Inode operation removexattr()
951 * dentry->d_inode->i_mutex down
953 int reiserfs_removexattr(struct dentry *dentry, const char *name)
956 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_write_lock_xattr_i(dentry->d_inode);
963 reiserfs_read_lock_xattrs(dentry->d_sb);
965 /* Deletion pre-operation */
967 err = xah->del(dentry->d_inode, name);
972 err = reiserfs_xattr_del(dentry->d_inode, name);
974 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
975 mark_inode_dirty(dentry->d_inode);
978 reiserfs_read_unlock_xattrs(dentry->d_sb);
979 reiserfs_write_unlock_xattr_i(dentry->d_inode);
983 /* This is what filldir will use:
984 * r_pos will always contain the amount of space required for the entire
985 * list. If r_pos becomes larger than r_size, we need more space and we
986 * return an error indicating this. If r_pos is less than r_size, then we've
987 * filled the buffer successfully and we return success */
988 struct reiserfs_listxattr_buf {
992 struct inode *r_inode;
996 reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
997 loff_t offset, u64 ino, unsigned int d_type)
999 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
1002 || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
1003 struct reiserfs_xattr_handler *xah =
1004 find_xattr_handler_prefix(name);
1006 return 0; /* Unsupported xattr name, skip it */
1008 /* We call ->list() twice because the operation isn't required to just
1009 * return the name back - we want to make sure we have enough space */
1010 len += xah->list(b->r_inode, name, namelen, NULL);
1013 if (b->r_pos + len + 1 <= b->r_size) {
1014 char *p = b->r_buf + b->r_pos;
1015 p += xah->list(b->r_inode, name, namelen, p);
1018 b->r_pos += len + 1;
1026 * Inode operation listxattr()
1028 * Preliminary locking: we down dentry->d_inode->i_mutex
1030 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
1035 struct reiserfs_listxattr_buf buf;
1037 if (!dentry->d_inode)
1040 if (!reiserfs_xattrs(dentry->d_sb) ||
1041 get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
1044 reiserfs_read_lock_xattr_i(dentry->d_inode);
1045 reiserfs_read_lock_xattrs(dentry->d_sb);
1046 dir = open_xa_dir(dentry->d_inode, FL_READONLY);
1047 reiserfs_read_unlock_xattrs(dentry->d_sb);
1050 if (err == -ENODATA)
1051 err = 0; /* Not an error if there aren't any xattrs */
1055 fp = dentry_open(dir, NULL, O_RDWR);
1058 /* dentry_open dputs the dentry if it fails */
1063 buf.r_size = buffer ? size : 0;
1065 buf.r_inode = dentry->d_inode;
1067 REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
1069 err = xattr_readdir(fp, reiserfs_listxattr_filler, &buf);
1073 if (buf.r_pos > buf.r_size && buffer != NULL)
1082 reiserfs_read_unlock_xattr_i(dentry->d_inode);
1086 /* This is the implementation for the xattr plugin infrastructure */
1087 static LIST_HEAD(xattr_handlers);
1088 static DEFINE_RWLOCK(handler_lock);
1090 static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
1093 struct reiserfs_xattr_handler *xah = NULL;
1094 struct list_head *p;
1096 read_lock(&handler_lock);
1097 list_for_each(p, &xattr_handlers) {
1098 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1099 if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
1104 read_unlock(&handler_lock);
1108 static void __unregister_handlers(void)
1110 struct reiserfs_xattr_handler *xah;
1111 struct list_head *p, *tmp;
1113 list_for_each_safe(p, tmp, &xattr_handlers) {
1114 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1120 INIT_LIST_HEAD(&xattr_handlers);
1123 int __init reiserfs_xattr_register_handlers(void)
1126 struct reiserfs_xattr_handler *xah;
1127 struct list_head *p;
1129 write_lock(&handler_lock);
1131 /* If we're already initialized, nothing to do */
1132 if (!list_empty(&xattr_handlers)) {
1133 write_unlock(&handler_lock);
1137 /* Add the handlers */
1138 list_add_tail(&user_handler.handlers, &xattr_handlers);
1139 list_add_tail(&trusted_handler.handlers, &xattr_handlers);
1140 #ifdef CONFIG_REISERFS_FS_SECURITY
1141 list_add_tail(&security_handler.handlers, &xattr_handlers);
1143 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1144 list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
1145 list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
1148 /* Run initializers, if available */
1149 list_for_each(p, &xattr_handlers) {
1150 xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
1160 /* Clean up other handlers, if any failed */
1162 __unregister_handlers();
1164 write_unlock(&handler_lock);
1168 void reiserfs_xattr_unregister_handlers(void)
1170 write_lock(&handler_lock);
1171 __unregister_handlers();
1172 write_unlock(&handler_lock);
1175 /* This will catch lookups from the fs root to .reiserfs_priv */
1177 xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
1179 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1180 if (name->len == priv_root->d_name.len &&
1181 name->hash == priv_root->d_name.hash &&
1182 !memcmp(name->name, priv_root->d_name.name, name->len)) {
1184 } else if (q1->len == name->len &&
1185 !memcmp(q1->name, name->name, name->len))
1190 static struct dentry_operations xattr_lookup_poison_ops = {
1191 .d_compare = xattr_lookup_poison,
1194 /* We need to take a copy of the mount flags since things like
1195 * MS_RDONLY don't get set until *after* we're called.
1196 * mount_flags != mount_options */
1197 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
1201 /* We need generation numbers to ensure that the oid mapping is correct
1202 * v3.5 filesystems don't have them. */
1203 if (!old_format_only(s)) {
1204 set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1205 } else if (reiserfs_xattrs_optional(s)) {
1206 /* Old format filesystem, but optional xattrs have been enabled
1207 * at mount time. Error out. */
1208 reiserfs_warning(s, "xattrs/ACLs not supported on pre v3.6 "
1209 "format filesystem. Failing mount.");
1213 /* Old format filesystem, but no optional xattrs have been enabled. This
1214 * means we silently disable xattrs on the filesystem. */
1215 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1218 /* If we don't have the privroot located yet - go find it */
1219 if (reiserfs_xattrs(s) && !REISERFS_SB(s)->priv_root) {
1220 struct dentry *dentry;
1221 dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
1222 strlen(PRIVROOT_NAME));
1223 if (!IS_ERR(dentry)) {
1224 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
1225 struct inode *inode = dentry->d_parent->d_inode;
1226 mutex_lock_nested(&inode->i_mutex,
1228 err = inode->i_op->mkdir(inode, dentry, 0700);
1229 mutex_unlock(&inode->i_mutex);
1235 if (dentry && dentry->d_inode)
1237 "Created %s on %s - reserved for "
1242 } else if (!dentry->d_inode) {
1247 err = PTR_ERR(dentry);
1249 if (!err && dentry) {
1250 s->s_root->d_op = &xattr_lookup_poison_ops;
1251 reiserfs_mark_inode_private(dentry->d_inode);
1252 REISERFS_SB(s)->priv_root = dentry;
1253 } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
1254 /* If we're read-only it just means that the dir hasn't been
1255 * created. Not an error -- just no xattrs on the fs. We'll
1256 * check again if we go read-write */
1257 reiserfs_warning(s, "xattrs/ACLs enabled and couldn't "
1258 "find/create .reiserfs_priv. Failing mount.");
1264 /* This is only nonzero if there was an error initializing the xattr
1265 * directory or if there is a condition where we don't support them. */
1267 clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1268 clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1269 clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1272 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1273 s->s_flags = s->s_flags & ~MS_POSIXACL;
1274 if (reiserfs_posixacl(s))
1275 s->s_flags |= MS_POSIXACL;
1280 static int reiserfs_check_acl(struct inode *inode, int mask)
1282 struct posix_acl *acl;
1283 int error = -EAGAIN; /* do regular unix permission checks by default */
1285 reiserfs_read_lock_xattr_i(inode);
1286 reiserfs_read_lock_xattrs(inode->i_sb);
1288 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
1290 reiserfs_read_unlock_xattrs(inode->i_sb);
1291 reiserfs_read_unlock_xattr_i(inode);
1295 error = posix_acl_permission(inode, acl, mask);
1296 posix_acl_release(acl);
1297 } else if (PTR_ERR(acl) != -ENODATA)
1298 error = PTR_ERR(acl);
1304 int reiserfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1307 * We don't do permission checks on the internal objects.
1308 * Permissions are determined by the "owning" object.
1310 if (is_reiserfs_priv_object(inode))
1314 * Stat data v1 doesn't support ACLs.
1316 if (get_inode_sd_version(inode) == STAT_DATA_V1)
1317 return generic_permission(inode, mask, NULL);
1319 return generic_permission(inode, mask, reiserfs_check_acl);