From edcc37a0478836b4a51eafb1bcec6a52708f681d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 3 May 2009 06:00:05 -0400 Subject: Always lookup priv_root on reiserfs mount and keep it ... even if it's a negative dentry. That way we can set ->d_op on root before anyone could race with us. Simplify d_compare(), while we are at it. Signed-off-by: Al Viro --- fs/reiserfs/super.c | 6 ++- fs/reiserfs/xattr.c | 86 ++++++++++++++++++------------------------ include/linux/reiserfs_xattr.h | 1 + 3 files changed, 41 insertions(+), 52 deletions(-) diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index 0ae6486d9046..d444fe0013a4 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -1842,7 +1842,8 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent) goto error; } - if ((errval = reiserfs_xattr_init(s, s->s_flags))) { + if ((errval = reiserfs_lookup_privroot(s)) || + (errval = reiserfs_xattr_init(s, s->s_flags))) { dput(s->s_root); s->s_root = NULL; goto error; @@ -1855,7 +1856,8 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent) reiserfs_info(s, "using 3.5.x disk format\n"); } - if ((errval = reiserfs_xattr_init(s, s->s_flags))) { + if ((errval = reiserfs_lookup_privroot(s)) || + (errval = reiserfs_xattr_init(s, s->s_flags))) { dput(s->s_root); s->s_root = NULL; goto error; diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 31a3dbb120e1..2891f789f545 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -903,16 +903,19 @@ static int create_privroot(struct dentry *dentry) WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex)); err = xattr_mkdir(inode, dentry, 0700); - if (err) { - dput(dentry); - dentry = NULL; + if (err || !dentry->d_inode) { + reiserfs_warning(dentry->d_sb, "jdm-20006", + "xattrs/ACLs enabled and couldn't " + "find/create .reiserfs_priv. " + "Failing mount."); + return -EOPNOTSUPP; } - if (dentry && dentry->d_inode) - reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr " - "storage.\n", PRIVROOT_NAME); + dentry->d_inode->i_flags |= S_PRIVATE; + reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr " + "storage.\n", PRIVROOT_NAME); - return err; + return 0; } static int xattr_mount_check(struct super_block *s) @@ -944,11 +947,9 @@ 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)) { + if (container_of(q1, struct dentry, d_name) == priv_root) return -ENOENT; - } else if (q1->len == name->len && + if (q1->len == name->len && !memcmp(q1->name, name->name, name->len)) return 0; return 1; @@ -958,6 +959,27 @@ static const struct dentry_operations xattr_lookup_poison_ops = { .d_compare = xattr_lookup_poison, }; +int reiserfs_lookup_privroot(struct super_block *s) +{ + struct dentry *dentry; + int err = 0; + + /* If we don't have the privroot located yet - go find it */ + mutex_lock(&s->s_root->d_inode->i_mutex); + dentry = lookup_one_len(PRIVROOT_NAME, s->s_root, + strlen(PRIVROOT_NAME)); + if (!IS_ERR(dentry)) { + REISERFS_SB(s)->priv_root = dentry; + s->s_root->d_op = &xattr_lookup_poison_ops; + if (dentry->d_inode) + dentry->d_inode->i_flags |= S_PRIVATE; + } else + err = PTR_ERR(dentry); + mutex_unlock(&s->s_root->d_inode->i_mutex); + + return err; +} + /* 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 */ @@ -969,48 +991,12 @@ int reiserfs_xattr_init(struct super_block *s, int mount_flags) err = xattr_mount_check(s); if (err) goto error; -#endif - /* If we don't have the privroot located yet - go find it */ - if (!REISERFS_SB(s)->priv_root) { - struct dentry *dentry; - mutex_lock_nested(&s->s_root->d_inode->i_mutex, I_MUTEX_CHILD); - dentry = lookup_one_len(PRIVROOT_NAME, s->s_root, - strlen(PRIVROOT_NAME)); - if (!IS_ERR(dentry)) { -#ifdef CONFIG_REISERFS_FS_XATTR - if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) - err = create_privroot(dentry); -#endif - if (!dentry->d_inode) { - dput(dentry); - dentry = NULL; - } - } else - err = PTR_ERR(dentry); + if (!REISERFS_SB(s)->priv_root->d_inode && !(mount_flags & MS_RDONLY)) { + mutex_lock(&s->s_root->d_inode->i_mutex); + err = create_privroot(REISERFS_SB(s)->priv_root); mutex_unlock(&s->s_root->d_inode->i_mutex); - - if (!err && dentry) { - s->s_root->d_op = &xattr_lookup_poison_ops; - dentry->d_inode->i_flags |= S_PRIVATE; - REISERFS_SB(s)->priv_root = dentry; -#ifdef CONFIG_REISERFS_FS_XATTR - /* xattrs are unavailable */ - } else if (!(mount_flags & MS_RDONLY)) { - /* 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, "jdm-20006", - "xattrs/ACLs enabled and couldn't " - "find/create .reiserfs_priv. " - "Failing mount."); - err = -EOPNOTSUPP; -#endif - } } - -#ifdef CONFIG_REISERFS_FS_XATTR if (!err) s->s_xattr = reiserfs_xattr_handlers; diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h index dcae01e63e40..fea1a8e65bef 100644 --- a/include/linux/reiserfs_xattr.h +++ b/include/linux/reiserfs_xattr.h @@ -38,6 +38,7 @@ struct nameidata; int reiserfs_xattr_register_handlers(void) __init; void reiserfs_xattr_unregister_handlers(void); int reiserfs_xattr_init(struct super_block *sb, int mount_flags); +int reiserfs_lookup_privroot(struct super_block *sb); int reiserfs_delete_xattrs(struct inode *inode); int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs); -- cgit v1.2.3