nfs: don't create zero-length requests

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>
This commit is contained in:
Benjamin Coddington 2016-07-18 10:41:57 -04:00 committed by Trond Myklebust
parent ffb6ca33b0
commit 149a4fddd0

View file

@ -1291,6 +1291,9 @@ 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;
@ -1301,7 +1304,7 @@ 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;