nfs41: wait for LAYOUTRETURN before retrying LAYOUTGET
Also take care to stop waiting if someone clears retry bit.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 893f6b5..c4c9fe6 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1398,6 +1398,26 @@
return ret;
}
+/* stop waiting if someone clears NFS_LAYOUT_RETRY_LAYOUTGET bit. */
+static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key)
+{
+ if (!test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, key->flags))
+ return 1;
+ return nfs_wait_bit_killable(key);
+}
+
+static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
+{
+ /*
+ * send layoutcommit as it can hold up layoutreturn due to lseg
+ * reference
+ */
+ pnfs_layoutcommit_inode(lo->plh_inode, false);
+ return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
+ pnfs_layoutget_retry_bit_wait,
+ TASK_UNINTERRUPTIBLE);
+}
+
/*
* Layout segment is retreived from the server if not cached.
* The appropriate layout segment is referenced and returned to the caller.
@@ -1444,7 +1464,8 @@
}
/* if LAYOUTGET already failed once we don't try again */
- if (pnfs_layout_io_test_failed(lo, iomode))
+ if (pnfs_layout_io_test_failed(lo, iomode) &&
+ !pnfs_should_retry_layoutget(lo))
goto out_unlock;
first = list_empty(&lo->plh_segs);
@@ -1469,6 +1490,22 @@
goto out_unlock;
}
+ /*
+ * Because we free lsegs before sending LAYOUTRETURN, we need to wait
+ * for LAYOUTRETURN even if first is true.
+ */
+ if (!lseg && pnfs_should_retry_layoutget(lo) &&
+ test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
+ spin_unlock(&ino->i_lock);
+ dprintk("%s wait for layoutreturn\n", __func__);
+ if (pnfs_prepare_to_retry_layoutget(lo)) {
+ pnfs_put_layout_hdr(lo);
+ dprintk("%s retrying\n", __func__);
+ goto lookup_again;
+ }
+ goto out_put_layout_hdr;
+ }
+
if (pnfs_layoutgets_blocked(lo, &arg, 0))
goto out_unlock;
atomic_inc(&lo->plh_outstanding);