[PATCH] Fix current_io_context() vs set_task_ioprio() race

[pandora-kernel.git] / block / ll_rw_blk.c

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index fb83547..ddd9253 100644 (file)
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -10,7 +10,6 @@
 /*
  * This handles all read/write requests to block devices
  */
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/backing-dev.h>
@@ -2517,7 +2516,7 @@ EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
 int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
                   struct request *rq, int at_head)
 {
-       DECLARE_COMPLETION(wait);
+       DECLARE_COMPLETION_ONSTACK(wait);
        char sense[SCSI_SENSE_BUFFERSIZE];
        int err = 0;
 
@@ -3492,8 +3491,8 @@ EXPORT_SYMBOL(end_request);
 
 void blk_rq_bio_prep(request_queue_t *q, struct request *rq, struct bio *bio)
 {
-       /* first three bits are identical in rq->flags and bio->bi_rw */
-       rq->flags |= (bio->bi_rw & 7);
+       /* first two bits are identical in rq->flags and bio->bi_rw */
+       rq->flags |= (bio->bi_rw & 3);
 
        rq->nr_phys_segments = bio_phys_segments(q, bio);
        rq->nr_hw_segments = bio_hw_segments(q, bio);
@@ -3629,6 +3628,8 @@ struct io_context *current_io_context(gfp_t gfp_flags)
                ret->nr_batch_requests = 0; /* because this is 0 */
                ret->aic = NULL;
                ret->cic_root.rb_node = NULL;
+               /* make sure set_task_ioprio() sees the settings above */
+               smp_wmb();
                tsk->io_context = ret;
        }