NFSv4.1: turn off pNFS on ds connection failure
If a data server is unavailable, go through MDS.
Mark the deviceid containing the data server as a negative cache entry.
Do not try to connect to any data server on a deviceid marked as a negative
cache entry. Mark any layout that tries to use the marked deviceid as failed.
Inodes with a layout marked as fails will not use the layout for I/O, and will
not perform any more layoutgets.
Inodes without a layout will still do layoutget, but the layout will get
marked immediately.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 1f4c153..3e54514 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -739,15 +739,16 @@
dprintk("%s matches recall, use MDS\n", __func__);
goto out_unlock;
}
- /* Check to see if the layout for the given range already exists */
- lseg = pnfs_find_lseg(lo, iomode);
- if (lseg)
- goto out_unlock;
/* if LAYOUTGET already failed once we don't try again */
if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
goto out_unlock;
+ /* Check to see if the layout for the given range already exists */
+ lseg = pnfs_find_lseg(lo, iomode);
+ if (lseg)
+ goto out_unlock;
+
if (pnfs_layoutgets_blocked(lo, NULL, 0))
goto out_unlock;
atomic_inc(&lo->plh_outstanding);