nfs: fix page dirtying in NFS DIO read codepath

The NFS DIO code will dirty pages that catch read responses in order to
handle the case where someone is doing DIO reads into an mmapped buffer.
The existing code doesn't really do the right thing though since it
doesn't take into account the case where we might be attempting to read
past the EOF.

Fix the logic in that code to only dirty pages that ended up receiving
data from the read. Note too that it really doesn't matter if
NFS_IOHDR_ERROR is set or not. All that matters is if the page was
altered by the read.

Cc: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Jeff Layton 2012-12-12 12:36:31 -05:00 committed by Trond Myklebust
parent 67fad106a2
commit be7e985804

View file

@ -266,13 +266,8 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
struct nfs_page *req = nfs_list_entry(hdr->pages.next);
struct page *page = req->wb_page;
if (!PageCompound(page)) {
if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
if (bytes < hdr->good_bytes)
set_page_dirty(page);
} else
set_page_dirty(page);
}
if (!PageCompound(page) && bytes < hdr->good_bytes)
set_page_dirty(page);
bytes += req->wb_bytes;
nfs_list_remove_request(req);
nfs_direct_readpage_release(req);