Commit edcc37a0 authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 5a6059c3

fs/reiserfs/super.c

+4 −2
Original line number Diff line number Diff line
@@ -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;

fs/reiserfs/xattr.c

+36 −50
Original line number Diff line number Diff line
@@ -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)

	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;
@@ -958,59 +959,44 @@ static const 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 reiserfs_lookup_privroot(struct super_block *s)

{

	struct dentry *dentry;

	int err = 0;



#ifdef CONFIG_REISERFS_FS_XATTR

	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);

	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)) {

#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;

			}

		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);



		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

		}

	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 */

int reiserfs_xattr_init(struct super_block *s, int mount_flags)

{

	int err = 0;



#ifdef CONFIG_REISERFS_FS_XATTR

	err = xattr_mount_check(s);

	if (err)

		goto error;



	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)

		s->s_xattr = reiserfs_xattr_handlers;

include/linux/reiserfs_xattr.h

+1 −0
Original line number Diff line number Diff line
@@ -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);