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/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h
index 23f1e1e..ee0c907 100644
--- a/fs/nfs/nfs4filelayout.h
+++ b/fs/nfs/nfs4filelayout.h
@@ -55,10 +55,14 @@
atomic_t ds_count;
};
+/* nfs4_file_layout_dsaddr flags */
+#define NFS4_DEVICE_ID_NEG_ENTRY 0x00000001
+
struct nfs4_file_layout_dsaddr {
struct hlist_node node;
struct nfs4_deviceid deviceid;
atomic_t ref;
+ unsigned long flags;
u32 stripe_count;
u8 *stripe_indices;
u32 ds_num;