[CIFS] clean up page array when uncached write send fails

In the event that a send fails in an uncached write, or we end up
needing to reissue it (-EAGAIN case), we'll kfree the wdata but
the pages currently leak.

Fix this by adding a new kref release routine for uncached writedata
that releases the pages, and have the uncached codepaths use that.

[original patch by Jeff modified to fix minor formatting problems]

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 2013234b73ad..a3f7a9c3cc69 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1890,7 +1890,8 @@ smb2_writev_callback(struct mid_q_entry *mid)
 
 /* smb2_async_writev - send an async write, and set up mid to handle result */
 int
-smb2_async_writev(struct cifs_writedata *wdata)
+smb2_async_writev(struct cifs_writedata *wdata,
+                  void (*release)(struct kref *kref))
 {
         int rc = -EACCES;
         struct smb2_write_req *req = NULL;
@@ -1938,7 +1939,7 @@ smb2_async_writev(struct cifs_writedata *wdata)
                                 smb2_writev_callback, wdata, 0);
 
         if (rc) {
-                kref_put(&wdata->refcount, cifs_writedata_release);
+                kref_put(&wdata->refcount, release);
                 cifs_stats_fail_inc(tcon, SMB2_WRITE_HE);
         }