From 047fe3605235888f3ebcda0c728cb31937eadfe6 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 12 Jun 2012 15:24:40 +0200 Subject: splice: fix racy pipe->buffers uses Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered by splice_shrink_spd() called from vmsplice_to_pipe() commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes) added capability to adjust pipe->buffers. Problem is some paths don't hold pipe mutex and assume pipe->buffers doesn't change for their duration. Fix this by adding nr_pages_max field in struct splice_pipe_desc, and use it in place of pipe->buffers where appropriate. splice_shrink_spd() loses its struct pipe_inode_info argument. Reported-by: Dave Jones Signed-off-by: Eric Dumazet Cc: Jens Axboe Cc: Alexander Viro Cc: Tom Herbert Cc: stable # 2.6.35 Tested-by: Dave Jones Signed-off-by: Jens Axboe --- include/linux/splice.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/splice.h b/include/linux/splice.h index 26e5b613ded..09a545a7dfa 100644 --- a/include/linux/splice.h +++ b/include/linux/splice.h @@ -51,7 +51,8 @@ struct partial_page { struct splice_pipe_desc { struct page **pages; /* page map */ struct partial_page *partial; /* pages[] may not be contig */ - int nr_pages; /* number of pages in map */ + int nr_pages; /* number of populated pages in map */ + unsigned int nr_pages_max; /* pages[] & partial[] arrays size */ unsigned int flags; /* splice flags */ const struct pipe_buf_operations *ops;/* ops associated with output pipe */ void (*spd_release)(struct splice_pipe_desc *, unsigned int); @@ -85,9 +86,8 @@ extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, /* * for dynamic pipe sizing */ -extern int splice_grow_spd(struct pipe_inode_info *, struct splice_pipe_desc *); -extern void splice_shrink_spd(struct pipe_inode_info *, - struct splice_pipe_desc *); +extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *); +extern void splice_shrink_spd(struct splice_pipe_desc *); extern void spd_release_page(struct splice_pipe_desc *, unsigned int); extern const struct pipe_buf_operations page_cache_pipe_buf_ops; -- cgit v1.2.3-18-g5258 From 76aaa5101fffaef12b45b4c01ed0d0528f23dedf Mon Sep 17 00:00:00 2001 From: Asias He Date: Thu, 14 Jun 2012 09:04:07 +0200 Subject: block: Drop dead function blk_abort_queue() This function was only used by btrfs code in btrfs_abort_devices() (seems in a wrong way). It was removed in commit d07eb9117050c9ed3f78296ebcc06128b52693be, So, Let's remove the dead code to avoid any confusion. Changes in v2: update commit log, btrfs_abort_devices() was removed already. Cc: Jens Axboe Cc: linux-kernel@vger.kernel.org Cc: Chris Mason Cc: linux-btrfs@vger.kernel.org Cc: David Sterba Signed-off-by: Asias He Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ba43f408baa..07954b05b86 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -827,7 +827,6 @@ extern bool __blk_end_request_err(struct request *rq, int error); extern void blk_complete_request(struct request *); extern void __blk_complete_request(struct request *); extern void blk_abort_request(struct request *); -extern void blk_abort_queue(struct request_queue *); extern void blk_unprep_request(struct request *); /* -- cgit v1.2.3-18-g5258