Commit cfb2f9d5 authored Sep 12, 2014 by Al Viro Committed by Steven Whitehouse Sep 12, 2014

GFS2: fix d_splice_alias() misuses



Callers of d_splice_alias(dentry, inode) don't need iput(), neither
on success nor on failure.  Either the reference to inode is stored
in a previously negative dentry, or it's dropped.  In either case
inode reference the caller used to hold is consumed.

__gfs2_lookup() does iput() in case when d_splice_alias() has failed.
Double iput() if we ever hit that.  And gfs2_create_inode() ends up
not only with double iput(), but with link count dropped to zero - on
an inode it has just found in directory.

Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

parent a937cca2

fs/gfs2/inode.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -626,8 +626,10 @@ static int gfs2_create_inode(struct inode dir, struct dentry dentry,
		if (!IS_ERR(inode)) {
		d = d_splice_alias(inode, dentry);
		error = PTR_ERR(d);
		if (IS_ERR(d))
		if (IS_ERR(d)) {
		inode = ERR_CAST(d);
		goto fail_gunlock;
		}
		error = 0;
		if (file) {
		if (S_ISREG(inode->i_mode)) {
		@@ -856,7 +858,6 @@ static struct dentry __gfs2_lookup(struct inode dir, struct dentry *dentry,

		d = d_splice_alias(inode, dentry);
		if (IS_ERR(d)) {
		iput(inode);
		gfs2_glock_dq_uninit(&gh);
		return d;
		}