summaryrefslogtreecommitdiff
path: root/drivers/block/xen-blkback
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-25 21:38:18 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-25 21:38:18 +0400
commit8ded371f81fba8b38a049f8c5f30ce6438fc7b75 (patch)
tree0684d176cb6f35c92c4bf0185b1af9f5380077eb /drivers/block/xen-blkback
parent096a705bbc080a4041636d07514560da8d78acbe (diff)
parent07d0c38e7d84f911c72058a124c7f17b3c779a65 (diff)
downloadlinux-8ded371f81fba8b38a049f8c5f30ce6438fc7b75.tar.xz
Merge branch 'for-3.1/drivers' of git://git.kernel.dk/linux-block
* 'for-3.1/drivers' of git://git.kernel.dk/linux-block: cciss: do not attempt to read from a write-only register xen/blkback: Add module alias for autoloading xen/blkback: Don't let in-flight requests defer pending ones. bsg: fix address space warning from sparse bsg: remove unnecessary conditional expressions bsg: fix bsg_poll() to return POLLOUT properly
Diffstat (limited to 'drivers/block/xen-blkback')
-rw-r--r--drivers/block/xen-blkback/blkback.c37
1 files changed, 20 insertions, 17 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 5cf2993a8338..2330a9ad5e95 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -458,7 +458,8 @@ static void end_block_io_op(struct bio *bio, int error)
* (which has the sectors we want, number of them, grant references, etc),
* and transmute it to the block API to hand it over to the proper block disk.
*/
-static int do_block_io_op(struct xen_blkif *blkif)
+static int
+__do_block_io_op(struct xen_blkif *blkif)
{
union blkif_back_rings *blk_rings = &blkif->blk_rings;
struct blkif_request req;
@@ -515,6 +516,23 @@ static int do_block_io_op(struct xen_blkif *blkif)
return more_to_do;
}
+static int
+do_block_io_op(struct xen_blkif *blkif)
+{
+ union blkif_back_rings *blk_rings = &blkif->blk_rings;
+ int more_to_do;
+
+ do {
+ more_to_do = __do_block_io_op(blkif);
+ if (more_to_do)
+ break;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&blk_rings->common, more_to_do);
+ } while (more_to_do);
+
+ return more_to_do;
+}
+
/*
* Transmutation of the 'struct blkif_request' to a proper 'struct bio'
* and call the 'submit_bio' to pass it to the underlying storage.
@@ -700,7 +718,6 @@ static void make_response(struct xen_blkif *blkif, u64 id,
struct blkif_response resp;
unsigned long flags;
union blkif_back_rings *blk_rings = &blkif->blk_rings;
- int more_to_do = 0;
int notify;
resp.id = id;
@@ -727,22 +744,7 @@ static void make_response(struct xen_blkif *blkif, u64 id,
}
blk_rings->common.rsp_prod_pvt++;
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blk_rings->common, notify);
- if (blk_rings->common.rsp_prod_pvt == blk_rings->common.req_cons) {
- /*
- * Tail check for pending requests. Allows frontend to avoid
- * notifications if requests are already in flight (lower
- * overheads and promotes batching).
- */
- RING_FINAL_CHECK_FOR_REQUESTS(&blk_rings->common, more_to_do);
-
- } else if (RING_HAS_UNCONSUMED_REQUESTS(&blk_rings->common)) {
- more_to_do = 1;
- }
-
spin_unlock_irqrestore(&blkif->blk_ring_lock, flags);
-
- if (more_to_do)
- blkif_notify_work(blkif);
if (notify)
notify_remote_via_irq(blkif->irq);
}
@@ -824,3 +826,4 @@ static int __init xen_blkif_init(void)
module_init(xen_blkif_init);
MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vbd");