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path: root/drivers/block/xen-blkback/blkback.c
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Diffstat (limited to 'drivers/block/xen-blkback/blkback.c')
-rw-r--r--drivers/block/xen-blkback/blkback.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index c4bc85e69d3..ed85ba94b2e 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -276,6 +276,8 @@ int xen_blkif_schedule(void *arg)
printk(KERN_DEBUG "%s: started\n", current->comm);
while (!kthread_should_stop()) {
+ struct blk_plug plug;
+
if (try_to_freeze())
continue;
if (unlikely(vbd->size != vbd_sz(vbd)))
@@ -292,9 +294,13 @@ int xen_blkif_schedule(void *arg)
blkif->waiting_reqs = 0;
smp_mb(); /* clear flag *before* checking for work */
+ blk_start_plug(&plug);
+
if (do_block_io_op(blkif))
blkif->waiting_reqs = 1;
+ blk_finish_plug(&plug);
+
if (log_stats && time_after(jiffies, blkif->st_print))
print_stats(blkif);
}
@@ -547,7 +553,6 @@ static void dispatch_rw_block_io(struct blkif_st *blkif,
struct bio *biolist[BLKIF_MAX_SEGMENTS_PER_REQUEST];
int i, nbio = 0;
int operation;
- struct blk_plug plug;
switch (req->operation) {
case BLKIF_OP_READ:
@@ -660,15 +665,9 @@ static void dispatch_rw_block_io(struct blkif_st *blkif,
*/
atomic_set(&pending_req->pendcnt, nbio);
- /* Get a reference count for the disk queue and start sending I/O */
- blk_start_plug(&plug);
-
for (i = 0; i < nbio; i++)
submit_bio(operation, biolist[i]);
- blk_finish_plug(&plug);
- /* Let the I/Os go.. */
-
if (operation == READ)
blkif->st_rd_sect += preq.nr_sects;
else if (operation == WRITE || operation == WRITE_BARRIER)