Commit cf4f30b2 authored Jul 18, 2016 by Benjamin Coddington Committed by Sasha Levin Aug 22, 2016

nfs: don't create zero-length requests



[ Upstream commit 149a4fddd0a72d526abbeac0c8deaab03559836a ]

NFS doesn't expect requests with wb_bytes set to zero and may make
unexpected decisions about how to handle that request at the page IO layer.
Skip request creation if we won't have any wb_bytes in the request.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Weston Andros Adamson <dros@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

parent f9fef43a

fs/nfs/write.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -1204,6 +1204,9 @@ int nfs_updatepage(struct file file, struct page page,
		dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n",
		file, count, (long long)(page_file_offset(page) + offset));

		if (!count)
		goto out;

		if (nfs_can_extend_write(file, page, inode)) {
		count = max(count + offset, nfs_page_length(page));
		offset = 0;
		@@ -1214,7 +1217,7 @@ int nfs_updatepage(struct file file, struct page page,
		nfs_set_pageerror(page);
		else
		__set_page_dirty_nobuffers(page);

		out:
		dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n",
		status, (long long)i_size_read(inode));
		return status;