From: Michael Holzheu Date: Fri, 30 May 2008 08:03:25 +0000 (+0200) Subject: [S390] tape: Fix race condition in tape block device driver X-Git-Tag: v2.6.26-rc5~35^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f71ad62a264a89cb1952df0c92b167005de8d1b0;p=pandora-kernel.git [S390] tape: Fix race condition in tape block device driver Due to incorrect function call sequence it can happen that a tape block request is finished before the request is taken from the block request queue. The following sequence leads to that condition: * tapeblock_start_request() -> start CCW program * Request finishes -> IO interrupt * tapeblock_end_request() * end_that_request_last() If blkdev_dequeue_request() has not been called before end_that_request_last(), a kernel bug is triggered in end_that_request_last() because the request is still queued. To solve that problem blkdev_dequeue_request() has to be called before starting the CCW program. Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- Reading git-diff-tree failed