tree c84b87396be32d529b9902a7261b772b1d919e8b
parent 8b3d3567f72aa61d5d6f4ce89d289b154e1ea866
author Miklos Szeredi <mszeredi@suse.cz> 1215156917 +0200
committer Jens Axboe <jens.axboe@oracle.com> 1215157934 +0200

splice: fix generic_file_splice_read() race with page invalidation

If a page was invalidated during splicing from file to a pipe, then
generic_file_splice_read() could return a short or zero count.

This manifested itself in rare I/O errors seen on nfs exported fuse
filesystems.  This is because nfsd uses splice_direct_to_actor() to read
files, and fuse uses invalidate_inode_pages2() to invalidate stale data on
open.

Fix by redoing the page find/create if it was found to be truncated
(invalidated).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>