[PATCH 4.19 202/271] pnfs: Fix a problem where we gratuitously start doing I/O through the MDS

From: Greg Kroah-Hartman
Date: Thu Jul 25 2019 - 14:03:08 EST

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

commit 58bbeab425c6c5e318f5b6ae31d351331ddfb34b upstream.

If the client has to stop in pnfs_update_layout() to wait for another
layoutget to complete, it currently exits and defaults to I/O through
the MDS if the layoutget was successful.

Fixes: d03360aaf5cc ("pNFS: Ensure we return the error if someone kills...")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.20+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

fs/nfs/pnfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1867,7 +1867,7 @@ lookup_again:
lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding,
- if (IS_ERR(lseg) || !list_empty(&lo->plh_segs))
+ if (IS_ERR(lseg))
goto out_put_layout_hdr;
goto lookup_again;