There are a number of make_request based drivers which don't support
cache flushes. Filter out flush bio's in __generic_make_request() so
that they don't have to worry about them. All FLUSH/FUA requests with
data are converted to regular IO requests and empty ones are completed
immediately.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
block/blk-core.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 18455c4..495bdc4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1509,6 +1509,19 @@ static inline void __generic_make_request(struct bio *bio)
if (bio_check_eod(bio, nr_sectors))
goto end_io;
+ /*
+ * Filter flush bio's early so that make_request based
+ * drivers without flush support don't have to worry
+ * about them.
+ */
+ if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
+ bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
+ if (!nr_sectors) {
+ err = 0;
+ goto end_io;
+ }
+ }
+
if ((bio->bi_rw & REQ_DISCARD) &&
(!blk_queue_discard(q) ||
((bio->bi_rw & REQ_SECURE) &&
--
1.7.1
--
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