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authorDavid S. Miller <davem@davemloft.net>2011-09-22 03:23:13 -0400
committerDavid S. Miller <davem@davemloft.net>2011-09-22 03:23:13 -0400
commit8decf868790b48a727d7e7ca164f2bcd3c1389c0 (patch)
treeb759a5f861f842af7ea76f9011b579d06e9d5508 /block/blk-flush.c
parent3fc72370186be2f9d4d6ef06d99e1caa5d92c564 (diff)
parentd93dc5c4478c1fd5de85a3e8aece9aad7bbae044 (diff)
Merge branch 'master' of github.com:davem330/net
Conflicts: MAINTAINERS drivers/net/Kconfig drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c drivers/net/ethernet/broadcom/tg3.c drivers/net/wireless/iwlwifi/iwl-pci.c drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c drivers/net/wireless/rt2x00/rt2800usb.c drivers/net/wireless/wl12xx/main.c
Diffstat (limited to 'block/blk-flush.c')
-rw-r--r--block/blk-flush.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c
index bb21e4c36f70..491eb30a242d 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -95,11 +95,12 @@ static unsigned int blk_flush_policy(unsigned int fflags, struct request *rq)
{
unsigned int policy = 0;
+ if (blk_rq_sectors(rq))
+ policy |= REQ_FSEQ_DATA;
+
if (fflags & REQ_FLUSH) {
if (rq->cmd_flags & REQ_FLUSH)
policy |= REQ_FSEQ_PREFLUSH;
- if (blk_rq_sectors(rq))
- policy |= REQ_FSEQ_DATA;
if (!(fflags & REQ_FUA) && (rq->cmd_flags & REQ_FUA))
policy |= REQ_FSEQ_POSTFLUSH;
}
@@ -122,7 +123,7 @@ static void blk_flush_restore_request(struct request *rq)
/* make @rq a normal request */
rq->cmd_flags &= ~REQ_FLUSH_SEQ;
- rq->end_io = NULL;
+ rq->end_io = rq->flush.saved_end_io;
}
/**
@@ -300,9 +301,6 @@ void blk_insert_flush(struct request *rq)
unsigned int fflags = q->flush_flags; /* may change, cache */
unsigned int policy = blk_flush_policy(fflags, rq);
- BUG_ON(rq->end_io);
- BUG_ON(!rq->bio || rq->bio != rq->biotail);
-
/*
* @policy now records what operations need to be done. Adjust
* REQ_FLUSH and FUA for the driver.
@@ -312,6 +310,19 @@ void blk_insert_flush(struct request *rq)
rq->cmd_flags &= ~REQ_FUA;
/*
+ * An empty flush handed down from a stacking driver may
+ * translate into nothing if the underlying device does not
+ * advertise a write-back cache. In this case, simply
+ * complete the request.
+ */
+ if (!policy) {
+ __blk_end_bidi_request(rq, 0, 0, 0);
+ return;
+ }
+
+ BUG_ON(!rq->bio || rq->bio != rq->biotail);
+
+ /*
* If there's data but flush is not necessary, the request can be
* processed directly without going through flush machinery. Queue
* for normal execution.
@@ -319,6 +330,7 @@ void blk_insert_flush(struct request *rq)
if ((policy & REQ_FSEQ_DATA) &&
!(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {
list_add_tail(&rq->queuelist, &q->queue_head);
+ blk_run_queue_async(q);
return;
}
@@ -329,6 +341,7 @@ void blk_insert_flush(struct request *rq)
memset(&rq->flush, 0, sizeof(rq->flush));
INIT_LIST_HEAD(&rq->flush.list);
rq->cmd_flags |= REQ_FLUSH_SEQ;
+ rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
rq->end_io = flush_data_end_io;
blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0);