From b066a48c9532243894f93a06ca5a0ee2cc21a8dc Mon Sep 17 00:00:00 2001 From: Dave Kleikamp Date: Tue, 18 Nov 2008 03:49:05 +0000 Subject: prevent cifs_writepages() from skipping unwritten pages Fixes a data corruption under heavy stress in which pages could be left dirty after all open instances of a inode have been closed. In order to write contiguous pages whenever possible, cifs_writepages() asks pagevec_lookup_tag() for more pages than it may write at one time. Normally, it then resets index just past the last page written before calling pagevec_lookup_tag() again. If cifs_writepages() can't write the first page returned, it wasn't resetting index, and the next call to pagevec_lookup_tag() resulted in skipping all of the pages it previously returned, even though cifs_writepages() did nothing with them. This can result in data loss when the file descriptor is about to be closed. This patch ensures that index gets set back to the next returned page so that none get skipped. Signed-off-by: Dave Kleikamp Acked-by: Jeff Layton Cc: Shirish S Pargaonkar Signed-off-by: Steve French --- fs/cifs/file.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 1540adaa593d..6449e1aae621 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1404,7 +1404,10 @@ retry: if ((wbc->nr_to_write -= n_iov) <= 0) done = 1; index = next; - } + } else + /* Need to re-find the pages we skipped */ + index = pvec.pages[0]->index + 1; + pagevec_release(&pvec); } if (!scanned && !done) { -- cgit v1.2.3-58-ga151