diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 2 | ||||
| -rw-r--r-- | block/blk-flush.c | 85 | ||||
| -rw-r--r-- | block/blk.h | 3 |
3 files changed, 50 insertions, 40 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 8870ae40179d..18455c4f618a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1204,7 +1204,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) spin_lock_irq(q->queue_lock); - if (bio->bi_rw & REQ_HARDBARRIER) { + if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) { where = ELEVATOR_INSERT_FRONT; goto get_rq; } diff --git a/block/blk-flush.c b/block/blk-flush.c index dd873225da97..452c552e9ead 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -1,5 +1,5 @@ /* - * Functions related to barrier IO handling + * Functions to sequence FLUSH and FUA writes. */ #include <linux/kernel.h> #include <linux/module.h> @@ -9,6 +9,15 @@ #include "blk.h" +/* FLUSH/FUA sequences */ +enum { + QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */ + QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */ + QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */ + QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */ + QUEUE_FSEQ_DONE = (1 << 4), +}; + static struct request *queue_next_fseq(struct request_queue *q); unsigned blk_flush_cur_seq(struct request_queue *q) @@ -79,6 +88,7 @@ static void queue_flush(struct request_queue *q, struct request *rq, static struct request *queue_next_fseq(struct request_queue *q) { + struct request *orig_rq = q->orig_flush_rq; struct request *rq = &q->flush_rq; switch (blk_flush_cur_seq(q)) { @@ -87,12 +97,11 @@ static struct request *queue_next_fseq(struct request_queue *q) break; case QUEUE_FSEQ_DATA: - /* initialize proxy request and queue it */ + /* initialize proxy request, inherit FLUSH/FUA and queue it */ blk_rq_init(q, rq); - init_request_from_bio(rq, q->orig_flush_rq->bio); - rq->cmd_flags &= ~REQ_HARDBARRIER; - if (q->ordered & QUEUE_ORDERED_DO_FUA) - rq->cmd_flags |= REQ_FUA; + init_request_from_bio(rq, orig_rq->bio); + rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA); + rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA); rq->end_io = flush_data_end_io; elv_insert(q, rq, ELEVATOR_INSERT_FRONT); @@ -110,60 +119,58 @@ static struct request *queue_next_fseq(struct request_queue *q) struct request *blk_do_flush(struct request_queue *q, struct request *rq) { + unsigned int fflags = q->flush_flags; /* may change, cache it */ + bool has_flush = fflags & REQ_FLUSH, has_fua = fflags & REQ_FUA; + bool do_preflush = has_flush && (rq->cmd_flags & REQ_FLUSH); + bool do_postflush = has_flush && !has_fua && (rq->cmd_flags & REQ_FUA); unsigned skip = 0; - if (!(rq->cmd_flags & REQ_HARDBARRIER)) + /* + * Special case. If there's data but flush is not necessary, + * the request can be issued directly. + * + * Flush w/o data should be able to be issued directly too but + * currently some drivers assume that rq->bio contains + * non-zero data if it isn't NULL and empty FLUSH requests + * getting here usually have bio's without data. + */ + if (blk_rq_sectors(rq) && !do_preflush && !do_postflush) { + rq->cmd_flags &= ~REQ_FLUSH; + if (!has_fua) + rq->cmd_flags &= ~REQ_FUA; return rq; + } + /* + * Sequenced flushes can't be processed in parallel. If + * another one is already in progress, queue for later + * processing. + */ if (q->flush_seq) { - /* - * Sequenced flush is already in progress and they - * can't be processed in parallel. Queue for later - * processing. - */ list_move_tail(&rq->queuelist, &q->pending_flushes); return NULL; } - if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) { - /* - * Queue ordering not supported. Terminate - * with prejudice. - */ - blk_dequeue_request(rq); - __blk_end_request_all(rq, -EOPNOTSUPP); - return NULL; - } - /* * Start a new flush sequence */ q->flush_err = 0; - q->ordered = q->next_ordered; q->flush_seq |= QUEUE_FSEQ_STARTED; - /* - * For an empty barrier, there's no actual BAR request, which - * in turn makes POSTFLUSH unnecessary. Mask them off. - */ - if (!blk_rq_sectors(rq)) - q->ordered &= ~(QUEUE_ORDERED_DO_BAR | - QUEUE_ORDERED_DO_POSTFLUSH); - - /* stash away the original request */ + /* adjust FLUSH/FUA of the original request and stash it away */ + rq->cmd_flags &= ~REQ_FLUSH; + if (!has_fua) + rq->cmd_flags &= ~REQ_FUA; blk_dequeue_request(rq); q->orig_flush_rq = rq; - if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) + /* skip unneded sequences and return the first one */ + if (!do_preflush) skip |= QUEUE_FSEQ_PREFLUSH; - - if (!(q->ordered & QUEUE_ORDERED_DO_BAR)) + if (!blk_rq_sectors(rq)) skip |= QUEUE_FSEQ_DATA; - - if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH)) + if (!do_postflush) skip |= QUEUE_FSEQ_POSTFLUSH; - - /* complete skipped sequences and return the first sequence */ return blk_flush_complete_seq(q, skip, 0); } diff --git a/block/blk.h b/block/blk.h index 24b92bd78f37..a09c18b19116 100644 --- a/block/blk.h +++ b/block/blk.h @@ -60,6 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q) while (1) { while (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); + if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) || + rq == &q->flush_rq) + return rq; rq = blk_do_flush(q, rq); if (rq) return rq; |