releases/5.7.16/nfs-don-t-return-layout-segments-that-are-in-use.patch

From d474f96104bd4377573526ebae2ee212205a6839 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Wed, 5 Aug 2020 09:03:56 -0400
Subject: NFS: Don't return layout segments that are in use

From: Trond Myklebust <trond.myklebust@hammerspace.com>

commit d474f96104bd4377573526ebae2ee212205a6839 upstream.

If the NFS_LAYOUT_RETURN_REQUESTED flag is set, we want to return the
layout as soon as possible, meaning that the affected layout segments
should be marked as invalid, and should no longer be in use for I/O.

Fixes: f0b429819b5f ("pNFS: Ignore non-recalled layouts in pnfs_layout_need_return()")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/pnfs.c |   34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1226,31 +1226,27 @@ out:
 	return status;
 }
 
+static bool
+pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
+				enum pnfs_iomode iomode,
+				u32 seq)
+{
+	struct pnfs_layout_range recall_range = {
+		.length = NFS4_MAX_UINT64,
+		.iomode = iomode,
+	};
+	return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
+					       &recall_range, seq) != -EBUSY;
+}
+
 /* Return true if layoutreturn is needed */
 static bool
 pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
 {
-	struct pnfs_layout_segment *s;
-	enum pnfs_iomode iomode;
-	u32 seq;
-
 	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
 		return false;
-
-	seq = lo->plh_return_seq;
-	iomode = lo->plh_return_iomode;
-
-	/* Defer layoutreturn until all recalled lsegs are done */
-	list_for_each_entry(s, &lo->plh_segs, pls_list) {
-		if (seq && pnfs_seqid_is_newer(s->pls_seq, seq))
-			continue;
-		if (iomode != IOMODE_ANY && s->pls_range.iomode != iomode)
-			continue;
-		if (test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
-			return false;
-	}
-
-	return true;
+	return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
+					       lo->plh_return_seq);
 }
 
 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)