Commit d7c103d0 authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

[GFS2] Fix recursive locking attempt with NFS 



In certain cases, its possible for NFS to call the lookup code while
holding the glock (when doing a readdirplus operation) so we need to
check for that and not try and lock the glock twice. This also fixes a
typo in a previous NFS related GFS2 patch.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent b790c3b7

fs/gfs2/inode.c

+15 −8
Original line number Diff line number Diff line
@@ -395,8 +395,10 @@ struct inode *gfs2_lookup_simple(struct inode *dip, const char *name) 
 * @is_root: If 1, ignore the caller's permissions

 * @i_gh: An uninitialized holder for the new inode glock

 *

 * There will always be a vnode (Linux VFS inode) for the d_gh inode unless

 * @is_root is true.

 * This can be called via the VFS filldir function when NFS is doing

 * a readdirplus and the inode which its intending to stat isn't

 * already in cache. In this case we must not take the directory glock

 * again, since the readdir call will have already taken that lock.

 *

 * Returns: errno

 */
@@ -409,8 +411,9 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, 
	struct gfs2_holder d_gh;

	struct gfs2_inum_host inum;

	unsigned int type;

	int error = 0;

	int error;

	struct inode *inode = NULL;

	int unlock = 0;



	if (!name->len || name->len > GFS2_FNAMESIZE)

		return ERR_PTR(-ENAMETOOLONG);
@@ -422,9 +425,12 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, 
		return dir;

	}



	if (gfs2_glock_is_locked_by_me(dip->i_gl) == 0) {

		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);

		if (error)

			return ERR_PTR(error);

		unlock = 1;

	}



	if (!is_root) {

		error = permission(dir, MAY_EXEC, NULL);
@@ -439,10 +445,11 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, 
	inode = gfs2_inode_lookup(sb, &inum, type);



out:

	if (unlock)

		gfs2_glock_dq_uninit(&d_gh);

	if (error == -ENOENT)

		return NULL;

	return inode;

	return inode ? inode : ERR_PTR(error);

}



static int pick_formal_ino_1(struct gfs2_sbd *sdp, u64 *formal_ino)

fs/gfs2/ops_inode.c

+1 −1
Original line number Diff line number Diff line
@@ -1018,7 +1018,7 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry, 
	}



	generic_fillattr(inode, stat);

	if (unlock);

	if (unlock)

		gfs2_glock_dq_uninit(&gh);



	return 0;

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