--- /dev/null
+/*
+ * linux/fs/reiserfs/xattr.c
+ *
+ * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
+ *
+ */
+
+/*
+ * In order to implement EA/ACLs in a clean, backwards compatible manner,
+ * they are implemented as files in a "private" directory.
+ * Each EA is in it's own file, with the directory layout like so (/ is assumed
+ * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
+ * directories named using the capital-hex form of the objectid and
+ * generation number are used. Inside each directory are individual files
+ * named with the name of the extended attribute.
+ *
+ * So, for objectid 12648430, we could have:
+ * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
+ * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
+ * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
+ * .. or similar.
+ *
+ * The file contents are the text of the EA. The size is known based on the
+ * stat data describing the file.
+ *
+ * In the case of system.posix_acl_access and system.posix_acl_default, since
+ * these are special cases for filesystem ACLs, they are interpreted by the
+ * kernel, in addition, they are negatively and positively cached and attached
+ * to the inode so that unnecessary lookups are avoided.
+ */
+
+#include <linux/reiserfs_fs.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/xattr.h>
+#include <linux/reiserfs_xattr.h>
+#include <linux/reiserfs_acl.h>
+#include <linux/mbcache.h>
+#include <asm/uaccess.h>
+#include <asm/checksum.h>
+#include <linux/smp_lock.h>
+#include <linux/stat.h>
+#include <asm/semaphore.h>
+
+#define FL_READONLY 128
+#define FL_DIR_SEM_HELD 256
+#define PRIVROOT_NAME ".reiserfs_priv"
+#define XAROOT_NAME "xattrs"
+
+static struct reiserfs_xattr_handler *find_xattr_handler_prefix (const char *prefix);
+
+static struct dentry *
+create_xa_root (struct super_block *sb)
+{
+ struct dentry *privroot = dget (REISERFS_SB(sb)->priv_root);
+ struct dentry *xaroot;
+
+ /* This needs to be created at mount-time */
+ if (!privroot)
+ return ERR_PTR(-EOPNOTSUPP);
+
+ xaroot = lookup_one_len (XAROOT_NAME, privroot, strlen (XAROOT_NAME));
+ if (IS_ERR (xaroot)) {
+ goto out;
+ } else if (!xaroot->d_inode) {
+ int err;
+ down (&privroot->d_inode->i_sem);
+ err = privroot->d_inode->i_op->mkdir (privroot->d_inode, xaroot, 0700);
+ up (&privroot->d_inode->i_sem);
+
+ if (err) {
+ dput (xaroot);
+ dput (privroot);
+ return ERR_PTR (err);
+ }
+ REISERFS_SB(sb)->xattr_root = dget (xaroot);
+ }
+
+out:
+ dput (privroot);
+ return xaroot;
+}
+
+/* This will return a dentry, or error, refering to the xa root directory.
+ * If the xa root doesn't exist yet, the dentry will be returned without
+ * an associated inode. This dentry can be used with ->mkdir to create
+ * the xa directory. */
+static struct dentry *
+__get_xa_root (struct super_block *s)
+{
+ struct dentry *privroot = dget (REISERFS_SB(s)->priv_root);
+ struct dentry *xaroot = NULL;
+
+ if (IS_ERR (privroot) || !privroot)
+ return privroot;
+
+ xaroot = lookup_one_len (XAROOT_NAME, privroot, strlen (XAROOT_NAME));
+ if (IS_ERR (xaroot)) {
+ goto out;
+ } else if (!xaroot->d_inode) {
+ dput (xaroot);
+ xaroot = NULL;
+ goto out;
+ }
+
+ REISERFS_SB(s)->xattr_root = dget (xaroot);
+
+out:
+ dput (privroot);
+ return xaroot;
+}
+
+/* Returns the dentry (or NULL) referring to the root of the extended
+ * attribute directory tree. If it has already been retreived, it is used.
+ * Otherwise, we attempt to retreive it from disk. It may also return
+ * a pointer-encoded error.
+ */
+static inline struct dentry *
+get_xa_root (struct super_block *s)
+{
+ struct dentry *dentry = dget (REISERFS_SB(s)->xattr_root);
+
+ if (!dentry)
+ dentry = __get_xa_root (s);
+
+ return dentry;
+}
+
+/* Opens the directory corresponding to the inode's extended attribute store.
+ * If flags allow, the tree to the directory may be created. If creation is
+ * prohibited, -ENODATA is returned. */
+static struct dentry *
+open_xa_dir (const struct inode *inode, int flags)
+{
+ struct dentry *xaroot, *xadir;
+ char namebuf[17];
+
+ xaroot = get_xa_root (inode->i_sb);
+ if (IS_ERR (xaroot)) {
+ return xaroot;
+ } else if (!xaroot) {
+ if (flags == 0 || flags & XATTR_CREATE) {
+ xaroot = create_xa_root (inode->i_sb);
+ if (IS_ERR (xaroot))
+ return xaroot;
+ }
+ if (!xaroot)
+ return ERR_PTR (-ENODATA);
+ }
+
+ /* ok, we have xaroot open */
+
+ snprintf (namebuf, sizeof (namebuf), "%X.%X",
+ le32_to_cpu (INODE_PKEY (inode)->k_objectid),
+ inode->i_generation);
+ xadir = lookup_one_len (namebuf, xaroot, strlen (namebuf));
+ if (IS_ERR (xadir)) {
+ dput (xaroot);
+ return xadir;
+ }
+
+ if (!xadir->d_inode) {
+ int err;
+ if (flags == 0 || flags & XATTR_CREATE) {
+ /* Although there is nothing else trying to create this directory,
+ * another directory with the same hash may be created, so we need
+ * to protect against that */
+ err = xaroot->d_inode->i_op->mkdir (xaroot->d_inode, xadir, 0700);
+ if (err) {
+ dput (xaroot);
+ dput (xadir);
+ return ERR_PTR (err);
+ }
+ }
+ if (!xadir->d_inode) {
+ dput (xaroot);
+ dput (xadir);
+ return ERR_PTR (-ENODATA);
+ }
+ /* Newly created object.. Need to mark it private */
+ REISERFS_I(xadir->d_inode)->i_flags |= i_priv_object;
+ }
+
+ dput (xaroot);
+ return xadir;
+}
+
+/* Returns a dentry corresponding to a specific extended attribute file
+ * for the inode. If flags allow, the file is created. Otherwise, a
+ * valid or negative dentry, or an error is returned. */
+static struct dentry *
+get_xa_file_dentry (const struct inode *inode, const char *name, int flags)
+{
+ struct dentry *xadir, *xafile;
+ int err = 0;
+
+ xadir = open_xa_dir (inode, flags);
+ if (IS_ERR (xadir)) {
+ return ERR_PTR (PTR_ERR (xadir));
+ } else if (xadir && !xadir->d_inode) {
+ dput (xadir);
+ return ERR_PTR (-ENODATA);
+ }
+
+ xafile = lookup_one_len (name, xadir, strlen (name));
+ if (IS_ERR (xafile)) {
+ dput (xadir);
+ return ERR_PTR (PTR_ERR (xafile));
+ }
+
+ if (xafile->d_inode) { /* file exists */
+ if (flags & XATTR_CREATE) {
+ err = -EEXIST;
+ dput (xafile);
+ goto out;
+ }
+ } else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
+ goto out;
+ } else {
+ /* inode->i_sem is down, so nothing else can try to create
+ * the same xattr */
+ err = xadir->d_inode->i_op->create (xadir->d_inode, xafile,
+ 0700|S_IFREG, NULL);
+
+ if (err) {
+ dput (xafile);
+ goto out;
+ }
+ /* Newly created object.. Need to mark it private */
+ REISERFS_I(xafile->d_inode)->i_flags |= i_priv_object;
+ }
+
+out:
+ dput (xadir);
+ if (err)
+ xafile = ERR_PTR (err);
+ return xafile;
+}
+
+
+/* Opens a file pointer to the attribute associated with inode */
+static struct file *
+open_xa_file (const struct inode *inode, const char *name, int flags)
+{
+ struct dentry *xafile;
+ struct file *fp;
+
+ xafile = get_xa_file_dentry (inode, name, flags);
+ if (IS_ERR (xafile))
+ return ERR_PTR (PTR_ERR (xafile));
+ else if (!xafile->d_inode) {
+ dput (xafile);
+ return ERR_PTR (-ENODATA);
+ }
+
+ fp = dentry_open (xafile, NULL, O_RDWR);
+ /* dentry_open dputs the dentry if it fails */
+
+ return fp;
+}
+
+
+/*
+ * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
+ * we need to drop the path before calling the filldir struct. That
+ * would be a big performance hit to the non-xattr case, so I've copied
+ * the whole thing for now. --clm
+ *
+ * the big difference is that I go backwards through the directory,
+ * and don't mess with f->f_pos, but the idea is the same. Do some
+ * action on each and every entry in the directory.
+ *
+ * we're called with i_sem held, so there are no worries about the directory
+ * changing underneath us.
+ */
+static int __xattr_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
+ INITIALIZE_PATH (path_to_entry);
+ struct buffer_head * bh;
+ int entry_num;
+ struct item_head * ih, tmp_ih;
+ int search_res;
+ char * local_buf;
+ loff_t next_pos;
+ char small_buf[32] ; /* avoid kmalloc if we can */
+ struct reiserfs_de_head *deh;
+ int d_reclen;
+ char * d_name;
+ off_t d_off;
+ ino_t d_ino;
+ struct reiserfs_dir_entry de;
+
+
+ /* form key for search the next directory entry using f_pos field of
+ file structure */
+ next_pos = max_reiserfs_offset(inode);
+
+ while (1) {
+research:
+ if (next_pos <= DOT_DOT_OFFSET)
+ break;
+ make_cpu_key (&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
+
+ search_res = search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, &de);
+ if (search_res == IO_ERROR) {
+ // FIXME: we could just skip part of directory which could
+ // not be read
+ pathrelse(&path_to_entry);
+ return -EIO;
+ }
+
+ if (search_res == NAME_NOT_FOUND)
+ de.de_entry_num--;
+
+ set_de_name_and_namelen(&de);
+ entry_num = de.de_entry_num;
+ deh = &(de.de_deh[entry_num]);
+
+ bh = de.de_bh;
+ ih = de.de_ih;
+
+ if (!is_direntry_le_ih(ih)) {
+ reiserfs_warning(inode->i_sb, "not direntry %h", ih);
+ break;
+ }
+ copy_item_head(&tmp_ih, ih);
+
+ /* we must have found item, that is item of this directory, */
+ RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key),
+ "vs-9000: found item %h does not match to dir we readdir %K",
+ ih, &pos_key);
+
+ if (deh_offset(deh) <= DOT_DOT_OFFSET) {
+ break;
+ }
+
+ /* look for the previous entry in the directory */
+ next_pos = deh_offset (deh) - 1;
+
+ if (!de_visible (deh))
+ /* it is hidden entry */
+ continue;
+
+ d_reclen = entry_length(bh, ih, entry_num);
+ d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
+ d_off = deh_offset (deh);
+ d_ino = deh_objectid (deh);
+
+ if (!d_name[d_reclen - 1])
+ d_reclen = strlen (d_name);
+
+ if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)){
+ /* too big to send back to VFS */
+ continue ;
+ }
+
+ /* Ignore the .reiserfs_priv entry */
+ if (reiserfs_xattrs (inode->i_sb) &&
+ !old_format_only(inode->i_sb) &&
+ deh_objectid (deh) == le32_to_cpu (INODE_PKEY(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->k_objectid))
+ continue;
+
+ if (d_reclen <= 32) {
+ local_buf = small_buf ;
+ } else {
+ local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ;
+ if (!local_buf) {
+ pathrelse (&path_to_entry);
+ return -ENOMEM ;
+ }
+ if (item_moved (&tmp_ih, &path_to_entry)) {
+ reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
+
+ /* sigh, must retry. Do this same offset again */
+ next_pos = d_off;
+ goto research;
+ }
+ }
+
+ // Note, that we copy name to user space via temporary
+ // buffer (local_buf) because filldir will block if
+ // user space buffer is swapped out. At that time
+ // entry can move to somewhere else
+ memcpy (local_buf, d_name, d_reclen);
+
+ /* the filldir function might need to start transactions,
+ * or do who knows what. Release the path now that we've
+ * copied all the important stuff out of the deh
+ */
+ pathrelse (&path_to_entry);
+
+ if (filldir (dirent, local_buf, d_reclen, d_off, d_ino,
+ DT_UNKNOWN) < 0) {
+ if (local_buf != small_buf) {
+ reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
+ }
+ goto end;
+ }
+ if (local_buf != small_buf) {
+ reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
+ }
+ } /* while */
+
+end:
+ pathrelse (&path_to_entry);
+ return 0;
+}
+
+/*
+ * this could be done with dedicated readdir ops for the xattr files,
+ * but I want to get something working asap
+ * this is stolen from vfs_readdir
+ *
+ */
+static
+int xattr_readdir(struct file *file, filldir_t filler, void *buf)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ int res = -ENOTDIR;
+ if (!file->f_op || !file->f_op->readdir)
+ goto out;
+ down(&inode->i_sem);
+// down(&inode->i_zombie);
+ res = -ENOENT;
+ if (!IS_DEADDIR(inode)) {
+ lock_kernel();
+ res = __xattr_readdir(file, buf, filler);
+ unlock_kernel();
+ }
+// up(&inode->i_zombie);
+ up(&inode->i_sem);
+out:
+ return res;
+}
+
+
+/* Internal operations on file data */
+static inline void
+reiserfs_put_page(struct page *page)
+{
+ kunmap(page);
+ page_cache_release(page);
+}
+
+static struct page *
+reiserfs_get_page(struct inode *dir, unsigned long n)
+{
+ struct address_space *mapping = dir->i_mapping;
+ struct page *page;
+ /* We can deadlock if we try to free dentries,
+ and an unlink/rmdir has just occured - GFP_NOFS avoids this */
+ mapping->flags = (mapping->flags & ~__GFP_BITS_MASK) | GFP_NOFS;
+ page = read_cache_page (mapping, n,
+ (filler_t*)mapping->a_ops->readpage, NULL);
+ if (!IS_ERR(page)) {
+ wait_on_page_locked(page);
+ kmap(page);
+ if (!PageUptodate(page))
+ goto fail;
+
+ if (PageError(page))
+ goto fail;
+ }
+ return page;
+
+fail:
+ reiserfs_put_page(page);
+ return ERR_PTR(-EIO);
+}
+
+static inline __u32
+xattr_hash (const char *msg, int len)
+{
+ return csum_partial (msg, len, 0);
+}
+
+/* Generic extended attribute operations that can be used by xa plugins */
+
+/*
+ * inode->i_sem: down
+ */
+int
+reiserfs_xattr_set (struct inode *inode, const char *name, const void *buffer,
+ size_t buffer_size, int flags)
+{
+ int err = 0;
+ struct file *fp;
+ struct page *page;
+ char *data;
+ struct address_space *mapping;
+ size_t file_pos = 0;
+ size_t buffer_pos = 0;
+ struct inode *xinode;
+ struct iattr newattrs;
+ __u32 xahash = 0;
+
+ if (IS_RDONLY (inode))
+ return -EROFS;
+
+ if (IS_IMMUTABLE (inode) || IS_APPEND (inode))
+ return -EPERM;
+
+ if (get_inode_sd_version (inode) == STAT_DATA_V1)
+ return -EOPNOTSUPP;
+
+ /* Empty xattrs are ok, they're just empty files, no hash */
+ if (buffer && buffer_size)
+ xahash = xattr_hash (buffer, buffer_size);
+
+open_file:
+ fp = open_xa_file (inode, name, flags);
+ if (IS_ERR (fp)) {
+ err = PTR_ERR (fp);
+ goto out;
+ }
+
+ xinode = fp->f_dentry->d_inode;
+ REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+
+ /* we need to copy it off.. */
+ if (xinode->i_nlink > 1) {
+ fput(fp);
+ err = reiserfs_xattr_del (inode, name);
+ if (err < 0)
+ goto out;
+ /* We just killed the old one, we're not replacing anymore */
+ if (flags & XATTR_REPLACE)
+ flags &= ~XATTR_REPLACE;
+ goto open_file;
+ }
+
+ /* Resize it so we're ok to write there */
+ newattrs.ia_size = buffer_size;
+ newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
+ down (&xinode->i_sem);
+ err = notify_change(fp->f_dentry, &newattrs);
+ if (err)
+ goto out_filp;
+
+ mapping = xinode->i_mapping;
+ while (buffer_pos < buffer_size || buffer_pos == 0) {
+ size_t chunk;
+ size_t skip = 0;
+ size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
+ if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
+ chunk = PAGE_CACHE_SIZE;
+ else
+ chunk = buffer_size - buffer_pos;
+
+ page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT);
+ if (IS_ERR (page)) {
+ err = PTR_ERR (page);
+ goto out_filp;
+ }
+
+ lock_page (page);
+ data = page_address (page);
+
+ if (file_pos == 0) {
+ struct reiserfs_xattr_header *rxh;
+ skip = file_pos = sizeof (struct reiserfs_xattr_header);
+ if (chunk + skip > PAGE_CACHE_SIZE)
+ chunk = PAGE_CACHE_SIZE - skip;
+ rxh = (struct reiserfs_xattr_header *)data;
+ rxh->h_magic = cpu_to_le32 (REISERFS_XATTR_MAGIC);
+ rxh->h_hash = cpu_to_le32 (xahash);
+ }
+
+ err = mapping->a_ops->prepare_write (fp, page, page_offset,
+ page_offset + chunk + skip);
+ if (!err) {
+ if (buffer)
+ memcpy (data + skip, buffer + buffer_pos, chunk);
+ err = mapping->a_ops->commit_write (fp, page, page_offset,
+ page_offset + chunk + skip);
+ }
+ unlock_page (page);
+ reiserfs_put_page (page);
+ buffer_pos += chunk;
+ file_pos += chunk;
+ skip = 0;
+ if (err || buffer_size == 0 || !buffer)
+ break;
+ }
+
+ inode->i_ctime = CURRENT_TIME;
+ mark_inode_dirty (inode);
+
+out_filp:
+ up (&xinode->i_sem);
+ fput(fp);
+
+out:
+ return err;
+}
+
+/*
+ * inode->i_sem: down
+ */
+int
+reiserfs_xattr_get (const struct inode *inode, const char *name, void *buffer,
+ size_t buffer_size)
+{
+ ssize_t err = 0;
+ struct file *fp;
+ size_t isize;
+ size_t file_pos = 0;
+ size_t buffer_pos = 0;
+ struct page *page;
+ struct inode *xinode;
+ __u32 hash = 0;
+
+ if (name == NULL)
+ return -EINVAL;
+
+ /* We can't have xattrs attached to v1 items since they don't have
+ * generation numbers */
+ if (get_inode_sd_version (inode) == STAT_DATA_V1)
+ return -EOPNOTSUPP;
+
+ fp = open_xa_file (inode, name, FL_READONLY);
+ if (IS_ERR (fp)) {
+ err = PTR_ERR (fp);
+ goto out;
+ }
+
+ xinode = fp->f_dentry->d_inode;
+ isize = xinode->i_size;
+ REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+
+ /* Just return the size needed */
+ if (buffer == NULL) {
+ err = isize - sizeof (struct reiserfs_xattr_header);
+ goto out_dput;
+ }
+
+ if (buffer_size < isize - sizeof (struct reiserfs_xattr_header)) {
+ err = -ERANGE;
+ goto out_dput;
+ }
+
+ while (file_pos < isize) {
+ size_t chunk;
+ char *data;
+ size_t skip = 0;
+ if (isize - file_pos > PAGE_CACHE_SIZE)
+ chunk = PAGE_CACHE_SIZE;
+ else
+ chunk = isize - file_pos;
+
+ page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT);
+ if (IS_ERR (page)) {
+ err = PTR_ERR (page);
+ goto out_dput;
+ }
+
+ lock_page (page);
+ data = page_address (page);
+ if (file_pos == 0) {
+ struct reiserfs_xattr_header *rxh =
+ (struct reiserfs_xattr_header *)data;
+ skip = file_pos = sizeof (struct reiserfs_xattr_header);
+ chunk -= skip;
+ /* Magic doesn't match up.. */
+ if (rxh->h_magic != cpu_to_le32 (REISERFS_XATTR_MAGIC)) {
+ unlock_page (page);
+ reiserfs_put_page (page);
+ reiserfs_warning (inode->i_sb, "Invalid magic for xattr (%s) "
+ "associated with %k", name,
+ INODE_PKEY (inode));
+ err = -EIO;
+ goto out_dput;
+ }
+ hash = le32_to_cpu (rxh->h_hash);
+ }
+ memcpy (buffer + buffer_pos, data + skip, chunk);
+ unlock_page (page);
+ reiserfs_put_page (page);
+ file_pos += chunk;
+ buffer_pos += chunk;
+ skip = 0;
+ }
+ err = isize - sizeof (struct reiserfs_xattr_header);
+
+ if (xattr_hash (buffer, isize - sizeof (struct reiserfs_xattr_header)) != hash) {
+ reiserfs_warning (inode->i_sb, "Invalid hash for xattr (%s) associated "
+ "with %k", name, INODE_PKEY (inode));
+ err = -EIO;
+ }
+
+out_dput:
+ fput(fp);
+
+out:
+ return err;
+}
+
+static int
+__reiserfs_xattr_del (struct dentry *xadir, const char *name, int namelen)
+{
+ struct dentry *dentry;
+ struct inode *dir = xadir->d_inode;
+ int err = 0;
+
+ dentry = lookup_one_len (name, xadir, namelen);
+ if (IS_ERR (dentry)) {
+ err = PTR_ERR (dentry);
+ goto out;
+ } else if (!dentry->d_inode) {
+ err = -ENODATA;
+ goto out_file;
+ }
+
+ /* Skip directories.. */
+ if (S_ISDIR (dentry->d_inode->i_mode))
+ goto out_file;
+
+ if (!is_reiserfs_priv_object (dentry->d_inode)) {
+ reiserfs_warning (dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
+ "priv flag set [parent is %sset].",
+ le32_to_cpu (INODE_PKEY (dentry->d_inode)->k_objectid),
+ xadir->d_name.len, xadir->d_name.name, namelen, name,
+ is_reiserfs_priv_object (xadir->d_inode) ? "" : "not ");
+ dput (dentry);
+ return -EIO;
+ }
+
+ err = dir->i_op->unlink (dir, dentry);
+ if (!err)
+ d_delete (dentry);
+
+out_file:
+ dput (dentry);
+
+out:
+ return err;
+}
+
+
+int
+reiserfs_xattr_del (struct inode *inode, const char *name)
+{
+ struct dentry *dir;
+ int err;
+
+ if (IS_RDONLY (inode))
+ return -EROFS;
+
+ dir = open_xa_dir (inode, FL_READONLY);
+ if (IS_ERR (dir)) {
+ err = PTR_ERR (dir);
+ goto out;
+ }
+
+ err = __reiserfs_xattr_del (dir, name, strlen (name));
+ dput (dir);
+
+out:
+ return err;
+}
+
+/* The following are side effects of other operations that aren't explicitly
+ * modifying extended attributes. This includes operations such as permissions
+ * or ownership changes, object deletions, etc. */
+
+static int
+reiserfs_delete_xattrs_filler (void *buf, const char *name, int namelen,
+ loff_t offset, ino_t ino, unsigned int d_type)
+{
+ struct dentry *xadir = (struct dentry *)buf;
+
+ return __reiserfs_xattr_del (xadir, name, namelen);
+
+}
+
+/* This is called w/ inode->i_sem downed */
+int
+reiserfs_delete_xattrs (struct inode *inode)
+{
+ struct file *fp;
+ struct dentry *dir, *root;
+ int err = 0;
+
+ /* Skip out, an xattr has no xattrs associated with it */
+ if (is_reiserfs_priv_object (inode) ||
+ get_inode_sd_version (inode) == STAT_DATA_V1 ||
+ !reiserfs_xattrs(inode->i_sb))
+ {
+ return 0;
+ }
+ reiserfs_read_lock_xattrs (inode->i_sb);
+ dir = open_xa_dir (inode, FL_READONLY);
+ reiserfs_read_unlock_xattrs (inode->i_sb);
+ if (IS_ERR (dir)) {
+ err = PTR_ERR (dir);
+ goto out;
+ } else if (!dir->d_inode) {
+ dput (dir);
+ return 0;
+ }
+
+ fp = dentry_open (dir, NULL, O_RDWR);
+ if (IS_ERR (fp)) {
+ err = PTR_ERR (fp);
+ /* dentry_open dputs the dentry if it fails */
+ goto out;
+ }
+
+ lock_kernel ();
+ err = xattr_readdir (fp, reiserfs_delete_xattrs_filler, dir);
+ if (err) {
+ unlock_kernel ();
+ goto out_dir;
+ }
+
+ /* Leftovers besides . and .. -- that's not good. */
+ if (dir->d_inode->i_nlink <= 2) {
+ root = get_xa_root (inode->i_sb);
+ reiserfs_write_lock_xattrs (inode->i_sb);
+ err = vfs_rmdir (root->d_inode, dir);
+ reiserfs_write_unlock_xattrs (inode->i_sb);
+ dput (root);
+ } else {
+ reiserfs_warning (inode->i_sb,
+ "Couldn't remove all entries in directory");
+ }
+ unlock_kernel ();
+
+out_dir:
+ fput(fp);
+
+out:
+ if (!err)
+ REISERFS_I(inode)->i_flags = REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
+ return err;
+}
+
+struct reiserfs_chown_buf {
+ struct inode *inode;
+ struct dentry *xadir;
+ struct iattr *attrs;
+};
+
+/* XXX: If there is a better way to do this, I'd love to hear about it */
+static int
+reiserfs_chown_xattrs_filler (void *buf, const char *name, int namelen,
+ loff_t offset, ino_t ino, unsigned int d_type)
+{
+ struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
+ struct dentry *xafile, *xadir = chown_buf->xadir;
+ struct iattr *attrs = chown_buf->attrs;
+ int err = 0;
+
+ xafile = lookup_one_len (name, xadir, namelen);
+ if (IS_ERR (xafile))
+ return PTR_ERR (xafile);
+ else if (!xafile->d_inode) {
+ dput (xafile);
+ return -ENODATA;
+ }
+
+ if (!S_ISDIR (xafile->d_inode->i_mode))
+ err = notify_change (xafile, attrs);
+ dput (xafile);
+
+ return err;
+}
+
+int
+reiserfs_chown_xattrs (struct inode *inode, struct iattr *attrs)
+{
+ struct file *fp;
+ struct dentry *dir;
+ int err = 0;
+ struct reiserfs_chown_buf buf;
+ unsigned int ia_valid = attrs->ia_valid;
+
+ /* Skip out, an xattr has no xattrs associated with it */
+ if (is_reiserfs_priv_object (inode) ||
+ get_inode_sd_version (inode) == STAT_DATA_V1 ||
+ !reiserfs_xattrs(inode->i_sb))
+ {
+ return 0;
+ }
+ reiserfs_read_lock_xattrs (inode->i_sb);
+ dir = open_xa_dir (inode, FL_READONLY);
+ reiserfs_read_unlock_xattrs (inode->i_sb);
+ if (IS_ERR (dir)) {
+ if (PTR_ERR (dir) != -ENODATA)
+ err = PTR_ERR (dir);
+ goto out;
+ } else if (!dir->d_inode) {
+ dput (dir);
+ goto out;
+ }
+
+ fp = dentry_open (dir, NULL, O_RDWR);
+ if (IS_ERR (fp)) {
+ err = PTR_ERR (fp);
+ /* dentry_open dputs the dentry if it fails */
+ goto out;
+ }
+
+ lock_kernel ();
+
+ attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
+ buf.xadir = dir;
+ buf.attrs = attrs;
+ buf.inode = inode;
+
+ err = xattr_readdir (fp, reiserfs_chown_xattrs_filler, &buf);
+ if (err) {
+ unlock_kernel ();
+ goto out_dir;
+ }
+
+ err = notify_change (dir, attrs);
+ unlock_kernel ();
+
+out_dir:
+ fput(fp);
+
+out:
+ attrs->ia_valid = ia_valid;
+ return err;
+}
+
+
+/* Actual operations that are exported to VFS-land */
+
+/*
+ * Inode operation getxattr()
+ * Preliminary locking: we down dentry->d_inode->i_sem
+ */
+ssize_t
+reiserfs_getxattr (struct dentry *dentry, const char *name, void *buffer,
+ size_t size)
+{
+ struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+ int err;
+
+ if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
+ get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+ return -EOPNOTSUPP;
+
+ reiserfs_read_lock_xattr_i (dentry->d_inode);
+ reiserfs_read_lock_xattrs (dentry->d_sb);
+ err = xah->get (dentry->d_inode, name, buffer, size);
+ reiserfs_read_unlock_xattrs (dentry->d_sb);
+ reiserfs_read_unlock_xattr_i (dentry->d_inode);
+ return err;
+}
+
+
+/*
+ * Inode operation setxattr()
+ *
+ * dentry->d_inode->i_sem down
+ */
+int
+reiserfs_setxattr (struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
+{
+ struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+ int err;
+ int lock;
+
+ if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
+ get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+ return -EOPNOTSUPP;
+
+ if (IS_RDONLY (dentry->d_inode))
+ return -EROFS;
+
+ if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode))
+ return -EROFS;
+
+ reiserfs_write_lock_xattr_i (dentry->d_inode);
+ lock = !has_xattr_dir (dentry->d_inode);
+ if (lock)
+ reiserfs_write_lock_xattrs (dentry->d_sb);
+ else
+ reiserfs_read_lock_xattrs (dentry->d_sb);
+ err = xah->set (dentry->d_inode, name, value, size, flags);
+ if (lock)
+ reiserfs_write_unlock_xattrs (dentry->d_sb);
+ else
+ reiserfs_read_unlock_xattrs (dentry->d_sb);
+ reiserfs_write_unlock_xattr_i (dentry->d_inode);
+ return err;
+}
+
+/*
+ * Inode operation removexattr()
+ *
+ * dentry->d_inode->i_sem down
+ */
+int
+reiserfs_removexattr (struct dentry *dentry, const char *name)
+{
+ int err;
+ struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+
+ if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
+ get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+ return -EOPNOTSUPP;
+
+ if (IS_RDONLY (dentry->d_inode))
+ return -EROFS;
+
+ if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode))
+ return -EPERM;
+
+ reiserfs_write_lock_xattr_i (dentry->d_inode);
+ reiserfs_read_lock_xattrs (dentry->d_sb);
+
+ /* Deletion pre-operation */
+ if (xah->del) {
+ err = xah->del (dentry->d_inode, name);
+ if (err)
+ goto out;
+ }
+
+ err = reiserfs_xattr_del (dentry->d_inode, name);
+
+ dentry->d_inode->i_ctime = CURRENT_TIME;
+ mark_inode_dirty (dentry->d_inode);
+
+out:
+ reiserfs_read_unlock_xattrs (dentry->d_sb);
+ reiserfs_write_unlock_xattr_i (dentry->d_inode);
+ return err;
+}
+
+
+/* This is what filldir will use:
+ * r_pos will always contain the amount of space required for the entire
+ * list. If r_pos becomes larger than r_size, we need more space and we
+ * return an error indicating this. If r_pos is less than r_size, then we've
+ * filled the buffer successfully and we return success */
+struct reiserfs_listxattr_buf {
+ int r_pos;
+ int r_size;
+ char *r_buf;
+ struct inode *r_inode;
+};
+
+static int
+reiserfs_listxattr_filler (void *buf, const char *name, int namelen,
+ loff_t offset, ino_t ino, unsigned int d_type)
+{
+ struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
+ int len = 0;
+ if (name[0] != '.' || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
+ struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+ if (!xah) return 0; /* Unsupported xattr name, skip it */
+
+ /* We call ->list() twice because the operation isn't required to just
+ * return the name back - we want to make sure we have enough space */
+ len += xah->list (b->r_inode, name, namelen, NULL);
+
+ if (len) {
+ if (b->r_pos + len + 1 <= b->r_size) {
+ char *p = b->r_buf + b->r_pos;
+ p += xah->list (b->r_inode, name, namelen, p);
+ *p++ = '\0';
+ }
+ b->r_pos += len + 1;
+ }
+ }
+
+ return 0;
+}
+/*
+ * Inode operation listxattr()
+ *
+ * Preliminary locking: we down dentry->d_inode->i_sem
+ */
+ssize_t
+reiserfs_listxattr (struct dentry *dentry, char *buffer, size_t size)
+{
+ struct file *fp;
+ struct dentry *dir;
+ int err = 0;
+ struct reiserfs_listxattr_buf buf;
+
+ if (!dentry->d_inode)
+ return -EINVAL;
+
+ if (!reiserfs_xattrs(dentry->d_sb) ||
+ get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+ return -EOPNOTSUPP;
+
+ reiserfs_read_lock_xattr_i (dentry->d_inode);
+ reiserfs_read_lock_xattrs (dentry->d_sb);
+ dir = open_xa_dir (dentry->d_inode, FL_READONLY);
+ reiserfs_read_unlock_xattrs (dentry->d_sb);
+ if (IS_ERR (dir)) {
+ err = PTR_ERR (dir);
+ if (err == -ENODATA)
+ err = 0; /* Not an error if there aren't any xattrs */
+ goto out;
+ }
+
+ fp = dentry_open (dir, NULL, O_RDWR);
+ if (IS_ERR (fp)) {
+ err = PTR_ERR (fp);
+ /* dentry_open dputs the dentry if it fails */
+ goto out;
+ }
+
+ buf.r_buf = buffer;
+ buf.r_size = buffer ? size : 0;
+ buf.r_pos = 0;
+ buf.r_inode = dentry->d_inode;
+
+ REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
+
+ err = xattr_readdir (fp, reiserfs_listxattr_filler, &buf);
+ if (err)
+ goto out_dir;
+
+ if (buf.r_pos > buf.r_size && buffer != NULL)
+ err = -ERANGE;
+ else
+ err = buf.r_pos;
+
+out_dir:
+ fput(fp);
+
+out:
+ reiserfs_read_unlock_xattr_i (dentry->d_inode);
+ return err;
+}
+
+/* This is the implementation for the xattr plugin infrastructure */
+static struct list_head xattr_handlers = LIST_HEAD_INIT (xattr_handlers);
+static rwlock_t handler_lock = RW_LOCK_UNLOCKED;
+
+static struct reiserfs_xattr_handler *
+find_xattr_handler_prefix (const char *prefix)
+{
+ struct reiserfs_xattr_handler *xah = NULL;
+ struct list_head *p;
+
+ read_lock (&handler_lock);
+ list_for_each (p, &xattr_handlers) {
+ xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
+ if (strncmp (xah->prefix, prefix, strlen (xah->prefix)) == 0)
+ break;
+ xah = NULL;
+ }
+
+ read_unlock (&handler_lock);
+ return xah;
+}
+
+static void
+__unregister_handlers (void)
+{
+ struct reiserfs_xattr_handler *xah;
+ struct list_head *p, *tmp;
+
+ list_for_each_safe (p, tmp, &xattr_handlers) {
+ xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
+ if (xah->exit)
+ xah->exit();
+
+ list_del_init (p);
+ }
+ INIT_LIST_HEAD (&xattr_handlers);
+}
+
+int __init
+reiserfs_xattr_register_handlers (void)
+{
+ int err = 0;
+ struct reiserfs_xattr_handler *xah;
+ struct list_head *p;
+
+ write_lock (&handler_lock);
+
+ /* If we're already initialized, nothing to do */
+ if (!list_empty (&xattr_handlers)) {
+ write_unlock (&handler_lock);
+ return 0;
+ }
+
+ /* Add the handlers */
+ list_add_tail (&user_handler.handlers, &xattr_handlers);
+ list_add_tail (&trusted_handler.handlers, &xattr_handlers);
+#ifdef CONFIG_REISERFS_FS_SECURITY
+ list_add_tail (&security_handler.handlers, &xattr_handlers);
+#endif
+#ifdef CONFIG_REISERFS_FS_POSIX_ACL
+ list_add_tail (&posix_acl_access_handler.handlers, &xattr_handlers);
+ list_add_tail (&posix_acl_default_handler.handlers, &xattr_handlers);
+#endif
+
+ /* Run initializers, if available */
+ list_for_each (p, &xattr_handlers) {
+ xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
+ if (xah->init) {
+ err = xah->init ();
+ if (err) {
+ list_del_init (p);
+ break;
+ }
+ }
+ }
+
+ /* Clean up other handlers, if any failed */
+ if (err)
+ __unregister_handlers ();
+
+ write_unlock (&handler_lock);
+ return err;
+}
+
+void
+reiserfs_xattr_unregister_handlers (void)
+{
+ write_lock (&handler_lock);
+ __unregister_handlers ();
+ write_unlock (&handler_lock);
+}
+
+/* This will catch lookups from the fs root to .reiserfs_priv */
+static int
+xattr_lookup_poison (struct dentry *dentry, struct qstr *q1, struct qstr *name)
+{
+ struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
+ if (name->len == priv_root->d_name.len &&
+ name->hash == priv_root->d_name.hash &&
+ !memcmp (name->name, priv_root->d_name.name, name->len)) {
+ return -ENOENT;
+ }
+ return 0;
+}
+
+static struct dentry_operations xattr_lookup_poison_ops = {
+ .d_compare = xattr_lookup_poison,
+};
+
+
+/* We need to take a copy of the mount flags since things like
+ * MS_RDONLY don't get set until *after* we're called.
+ * mount_flags != mount_options */
+int
+reiserfs_xattr_init (struct super_block *s, int mount_flags)
+{
+ int err = 0;
+
+ /* We need generation numbers to ensure that the oid mapping is correct
+ * v3.5 filesystems don't have them. */
+ if (!old_format_only (s)) {
+ set_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
+ } else if (reiserfs_xattrs_optional (s)) {
+ /* Old format filesystem, but optional xattrs have been enabled
+ * at mount time. Error out. */
+ reiserfs_warning (s, "xattrs/ACLs not supported on pre v3.6 "
+ "format filesystem. Failing mount.");
+ err = -EOPNOTSUPP;
+ goto error;
+ } else {
+ /* Old format filesystem, but no optional xattrs have been enabled. This
+ * means we silently disable xattrs on the filesystem. */
+ clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
+ }
+
+ /* If we don't have the privroot located yet - go find it */
+ if (reiserfs_xattrs (s) && !REISERFS_SB(s)->priv_root) {
+ struct dentry *dentry;
+ dentry = lookup_one_len (PRIVROOT_NAME, s->s_root,
+ strlen (PRIVROOT_NAME));
+ if (!IS_ERR (dentry)) {
+ if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
+ struct inode *inode = dentry->d_parent->d_inode;
+ down (&inode->i_sem);
+ err = inode->i_op->mkdir (inode, dentry, 0700);
+ up (&inode->i_sem);
+ if (err) {
+ dput (dentry);
+ dentry = NULL;
+ }
+
+ if (dentry && dentry->d_inode)
+ reiserfs_warning (s, "Created %s on %s - reserved for "
+ "xattr storage.", PRIVROOT_NAME,
+ reiserfs_bdevname (inode->i_sb));
+ } else if (!dentry->d_inode) {
+ dput (dentry);
+ dentry = NULL;
+ }
+ } else
+ err = PTR_ERR (dentry);
+
+ if (!err && dentry) {
+ s->s_root->d_op = &xattr_lookup_poison_ops;
+ REISERFS_I(dentry->d_inode)->i_flags |= i_priv_object;
+ REISERFS_SB(s)->priv_root = dentry;
+ } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
+ /* If we're read-only it just means that the dir hasn't been
+ * created. Not an error -- just no xattrs on the fs. We'll
+ * check again if we go read-write */
+ reiserfs_warning (s, "xattrs/ACLs enabled and couldn't "
+ "find/create .reiserfs_priv. Failing mount.");
+ err = -EOPNOTSUPP;
+ }
+ }
+
+error:
+ /* This is only nonzero if there was an error initializing the xattr
+ * directory or if there is a condition where we don't support them. */
+ if (err) {
+ clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
+ clear_bit (REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
+ clear_bit (REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
+ }
+
+ /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
+ s->s_flags = s->s_flags & ~MS_POSIXACL;
+ if (reiserfs_posixacl (s))
+ s->s_flags |= MS_POSIXACL;
+
+ return err;
+}
+
+static int
+__reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd,
+ int need_lock)
+{
+ umode_t mode = inode->i_mode;
+
+ if (mask & MAY_WRITE) {
+ /*
+ * Nobody gets write access to a read-only fs.
+ */
+ if (IS_RDONLY(inode) &&
+ (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
+ return -EROFS;
+
+ /*
+ * Nobody gets write access to an immutable file.
+ */
+ if (IS_IMMUTABLE(inode))
+ return -EACCES;
+ }
+
+ /* We don't do permission checks on the internal objects.
+ * Permissions are determined by the "owning" object. */
+ if (is_reiserfs_priv_object (inode))
+ return 0;
+
+ if (current->fsuid == inode->i_uid) {
+ mode >>= 6;
+#ifdef CONFIG_REISERFS_FS_POSIX_ACL
+ } else if (reiserfs_posixacl(inode->i_sb) &&
+ get_inode_sd_version (inode) != STAT_DATA_V1) {
+ struct posix_acl *acl;
+
+ /* ACL can't contain additional permissions if
+ the ACL_MASK entry is 0 */
+ if (!(mode & S_IRWXG))
+ goto check_groups;
+
+ if (need_lock) {
+ reiserfs_read_lock_xattr_i (inode);
+ reiserfs_read_lock_xattrs (inode->i_sb);
+ }
+ acl = reiserfs_get_acl (inode, ACL_TYPE_ACCESS);
+ if (need_lock) {
+ reiserfs_read_unlock_xattrs (inode->i_sb);
+ reiserfs_read_unlock_xattr_i (inode);
+ }
+ if (IS_ERR (acl)) {
+ if (PTR_ERR (acl) == -ENODATA)
+ goto check_groups;
+ return PTR_ERR (acl);
+ }
+
+ if (acl) {
+ int err = posix_acl_permission (inode, acl, mask);
+ posix_acl_release (acl);
+ if (err == -EACCES) {
+ goto check_capabilities;
+ }
+ return err;
+ } else {
+ goto check_groups;
+ }
+#endif
+ } else {
+check_groups:
+ if (in_group_p(inode->i_gid))
+ mode >>= 3;
+ }
+
+ /*
+ * If the DACs are ok we don't need any capability check.
+ */
+ if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
+ return 0;
+
+check_capabilities:
+ /*
+ * Read/write DACs are always overridable.
+ * Executable DACs are overridable if at least one exec bit is set.
+ */
+ if (!(mask & MAY_EXEC) ||
+ (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
+ if (capable(CAP_DAC_OVERRIDE))
+ return 0;
+
+ /*
+ * Searching includes executable on directories, else just read.
+ */
+ if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
+ if (capable(CAP_DAC_READ_SEARCH))
+ return 0;
+
+ return -EACCES;
+}
+
+int
+reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd)
+{
+ return __reiserfs_permission (inode, mask, nd, 1);
+}
+
+int
+reiserfs_permission_locked (struct inode *inode, int mask, struct nameidata *nd)
+{
+ return __reiserfs_permission (inode, mask, nd, 0);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff