pNFS: On error, do not send LAYOUTGET until the LAYOUTRETURN has completed

If there is an I/O error, we should not call LAYOUTGET until the
LAYOUTRETURN that reports the error is complete.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.8+

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 9b7e88b7edfc..06bfcd277006 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -947,6 +947,7 @@ static void pnfs_clear_layoutcommit(struct inode *inode,
 void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 {
         clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
+        clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
         smp_mb__after_atomic();
         wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
         rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
@@ -960,8 +961,9 @@ pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
         /* Serialise LAYOUTGET/LAYOUTRETURN */
         if (atomic_read(&lo->plh_outstanding) != 0)
                 return false;
-        if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
+        if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
                 return false;
+        set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
         pnfs_get_layout_hdr(lo);
         if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
                 if (stateid != NULL) {
@@ -1954,6 +1956,8 @@ void pnfs_error_mark_layout_for_return(struct inode *inode,
 
         spin_lock(&inode->i_lock);
         pnfs_set_plh_return_info(lo, range.iomode, 0);
+        /* Block LAYOUTGET */
+        set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
         /*
          * mark all matching lsegs so that we are sure to have no live
          * segments at hand when sending layoutreturn. See pnfs_put_lseg()