NFS: Add a cond_resched() to nfs_commit_release_pages()

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

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 4a379d7918f23e1130468c2f58bfea3623035116..cf61108f8f8d8dcaf18b720ad06c4ef3171d0287 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1837,6 +1837,8 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)
                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)