NFS: Don't move layouts to plh_return_segs list while in use

If the layout segment is still in use for a read or a write, we should
not move it to the layout plh_return_segs list. If we do, we can end
up returning the layout while I/O is still in progress.

Fixes: e0b7d42 ("pNFS: Don't discard layout segments that are marked for return")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Author: Trond Myklebust

fs/nfs/pnfs.c

@@ -2392,16 +2392,6 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 	return ERR_PTR(-EAGAIN);
 }
 
-static int
-mark_lseg_invalid_or_return(struct pnfs_layout_segment *lseg,
-		struct list_head *tmp_list)
-{
-	if (!mark_lseg_invalid(lseg, tmp_list))
-		return 0;
-	pnfs_cache_lseg_for_layoutreturn(lseg->pls_layout, lseg);
-	return 1;
-}
-
 /**
  * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
  * @lo: pointer to layout header
@@ -2438,7 +2428,7 @@ pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
 				lseg, lseg->pls_range.iomode,
 				lseg->pls_range.offset,
 				lseg->pls_range.length);
-			if (mark_lseg_invalid_or_return(lseg, tmp_list))
+			if (mark_lseg_invalid(lseg, tmp_list))
 				continue;
 			remaining++;
 			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);