nfs41: do not return ENOMEM on LAYOUTUNAVAILABLE

A pNFS server may return LAYOUTUNAVAILABLE error on LAYOUTGET for files
which don't have any layout. In this situation pnfs_update_layout
currently returns NULL. As this NULL is converted into ENOMEM, IO
requests fails instead of falling back to MDS.

Do not return ENOMEM on LAYOUTUNAVAILABLE and let client retry through
MDS.

Fixes 8d40b0f148. I will suggest to backport this fix to affected
stable branches.

Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
[trondmy: Use IS_ERR_OR_NULL()]
Fixes: 8d40b0f148 ("NFS filelayout:call GETDEVICEINFO after...")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Tigran Mkrtchyan 2018-01-16 22:38:50 +01:00 committed by Trond Myklebust
parent 1b8d97b0a8
commit 7ff4cff637

View File

@ -895,9 +895,7 @@ fl_pnfs_update_layout(struct inode *ino,
lseg = pnfs_update_layout(ino, ctx, pos, count, iomode, strict_iomode,
gfp_flags);
if (!lseg)
lseg = ERR_PTR(-ENOMEM);
if (IS_ERR(lseg))
if (IS_ERR_OR_NULL(lseg))
goto out;
lo = NFS_I(ino)->layout;