4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yan, Zheng <zyan@xxxxxxxxxx>
commit efe328230dc01aa0b1269aad0b5fae73eea4677a upstream.
This reverts commit 8b8f53af1ed9df88a4c0fbfdf3db58f62060edf3.
splice_dentry() is used by three places. For two places, req->r_dentry
is passed to splice_dentry(). In the case of error, req->r_dentry does
not get updated. So splice_dentry() should not drop reference.
Cc: stable@xxxxxxxxxxxxxxx # 4.18+
Signed-off-by: "Yan, Zheng" <zyan@xxxxxxxxxx>
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ceph/inode.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1077,8 +1077,12 @@ static struct dentry *splice_dentry(stru
if (IS_ERR(realdn)) {
pr_err("splice_dentry error %ld %p inode %p ino %llx.%llx\n",
PTR_ERR(realdn), dn, in, ceph_vinop(in));
- dput(dn);
- dn = realdn; /* note realdn contains the error */
+ dn = realdn;
+ /*
+ * Caller should release 'dn' in the case of error.
+ * If 'req->r_dentry' is passed to this function,
+ * caller should leave 'req->r_dentry' untouched.
+ */
goto out;
} else if (realdn) {
dout("dn %p (%d) spliced with %p (%d) "
