From: FUJITA Tomonori Date: Fri, 3 Apr 2009 10:28:06 +0000 (+0900) Subject: [SCSI] sg: fix q->queue_lock on scsi_error_handler path X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=015640edb1f346e0b2eda703587c4cd1c310ec1d;p=deliverable%2Flinux.git [SCSI] sg: fix q->queue_lock on scsi_error_handler path sg_rq_end_io() is called via rq->end_io. In some rare cases, sg_rq_end_io calls blk_put_request/blk_rq_unmap_user (when a program issuing a command has gone before the command completion; e.g. by interrupting a program issuing a command before the command completes). We can't call blk_put_request/blk_rq_unmap_user in interrupt so the commit c96952ed7031e7c576ecf90cf95b8ec099d5295a uses execute_in_process_context(). The problem is that scsi_error_handler() calls rq->end_io too. We can't call blk_put_request/blk_rq_unmap_user too in this path (we hold q->queue_lock). To avoid the above problem, in these rare cases, this patch always uses schedule_work() instead of execute_in_process_context(). Signed-off-by: FUJITA Tomonori Acked-by: Douglas Gilbert Cc: Stable Tree Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 1e405184ed76..82312df9b0bf 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1312,8 +1312,10 @@ static void sg_rq_end_io(struct request *rq, int uptodate) wake_up_interruptible(&sfp->read_wait); kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN); kref_put(&sfp->f_ref, sg_remove_sfp); - } else - execute_in_process_context(sg_rq_end_io_usercontext, &srp->ew); + } else { + INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext); + schedule_work(&srp->ew.work); + } } static struct file_operations sg_fops = { @@ -2099,7 +2101,8 @@ static void sg_remove_sfp(struct kref *kref) write_unlock_irqrestore(&sg_index_lock, iflags); wake_up_interruptible(&sdp->o_excl_wait); - execute_in_process_context(sg_remove_sfp_usercontext, &sfp->ew); + INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext); + schedule_work(&sfp->ew.work); } static int