Patch "NFS: Add a cond_resched() to nfs_commit_release_pages()" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    NFS: Add a cond_resched() to nfs_commit_release_pages()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfs-add-a-cond_resched-to-nfs_commit_release_pages.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 7f1bda447c9bd48b415acedba6b830f61591601f Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Mon, 18 Dec 2017 14:39:13 -0500
Subject: NFS: Add a cond_resched() to nfs_commit_release_pages()

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

commit 7f1bda447c9bd48b415acedba6b830f61591601f upstream.

The commit list can get very large, and so we need a cond_resched()
in nfs_commit_release_pages() in order to ensure we don't hog the CPU
for excessive periods of time.

Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/write.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1806,6 +1806,8 @@ static void nfs_commit_release_pages(str
 		set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
 	next:
 		nfs_unlock_and_release_request(req);
+		/* Latency breaker */
+		cond_resched();
 	}
 	nfss = NFS_SERVER(data->inode);
 	if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)


Patches currently in stable-queue which might be from trond.myklebust@primarydata.com are

queue-4.9/nfs-pnfs-fix-nfs_direct_req-ref-leak-when-i-o-falls-back-to-the-mds.patch
queue-4.9/nfs-add-a-cond_resched-to-nfs_commit_release_pages.patch
queue-4.9/nfs-commit-direct-writes-even-if-they-fail-partially.patch
queue-4.9/nfs-fix-a-race-between-mmap-and-o_direct.patch