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From: Tejun Heo on 12 Aug 2010 08:50 With ordering requirements dropped, barrier and ordered are misnomers. Now all block layer does is sequencing FLUSH and FUA. Rename them to flush. Signed-off-by: Tejun Heo <tj(a)kernel.org> Cc: Christoph Hellwig <hch(a)infradead.org> --- block/blk-core.c | 21 +++++----- block/blk-flush.c | 98 +++++++++++++++++++++++------------------------ block/blk.h | 4 +- include/linux/blkdev.h | 26 ++++++------ 4 files changed, 73 insertions(+), 76 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 82bd6d9..efe391b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -136,7 +136,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio, { struct request_queue *q = rq->q; - if (&q->bar_rq != rq) { + if (&q->flush_rq != rq) { if (error) clear_bit(BIO_UPTODATE, &bio->bi_flags); else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) @@ -160,13 +160,12 @@ static void req_bio_endio(struct request *rq, struct bio *bio, if (bio->bi_size == 0) bio_endio(bio, error); } else { - /* - * Okay, this is the barrier request in progress, just - * record the error; + * Okay, this is the sequenced flush request in + * progress, just record the error; */ - if (error && !q->orderr) - q->orderr = error; + if (error && !q->flush_err) + q->flush_err = error; } } @@ -520,7 +519,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) init_timer(&q->unplug_timer); setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q); INIT_LIST_HEAD(&q->timeout_list); - INIT_LIST_HEAD(&q->pending_barriers); + INIT_LIST_HEAD(&q->pending_flushes); INIT_WORK(&q->unplug_work, blk_unplug_work); kobject_init(&q->kobj, &blk_queue_ktype); @@ -1758,11 +1757,11 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes) static void blk_account_io_done(struct request *req) { /* - * Account IO completion. bar_rq isn't accounted as a normal - * IO on queueing nor completion. Accounting the containing - * request is enough. + * Account IO completion. flush_rq isn't accounted as a + * normal IO on queueing nor completion. Accounting the + * containing request is enough. */ - if (blk_do_io_stat(req) && req != &req->q->bar_rq) { + if (blk_do_io_stat(req) && req != &req->q->flush_rq) { unsigned long duration = jiffies - req->start_time; const int rw = rq_data_dir(req); struct hd_struct *part; diff --git a/block/blk-flush.c b/block/blk-flush.c index e8b2e5c..dd87322 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -9,41 +9,38 @@ #include "blk.h" -static struct request *queue_next_ordseq(struct request_queue *q); +static struct request *queue_next_fseq(struct request_queue *q); -/* - * Cache flushing for ordered writes handling - */ -unsigned blk_ordered_cur_seq(struct request_queue *q) +unsigned blk_flush_cur_seq(struct request_queue *q) { - if (!q->ordseq) + if (!q->flush_seq) return 0; - return 1 << ffz(q->ordseq); + return 1 << ffz(q->flush_seq); } -static struct request *blk_ordered_complete_seq(struct request_queue *q, - unsigned seq, int error) +static struct request *blk_flush_complete_seq(struct request_queue *q, + unsigned seq, int error) { struct request *next_rq = NULL; - if (error && !q->orderr) - q->orderr = error; + if (error && !q->flush_err) + q->flush_err = error; - BUG_ON(q->ordseq & seq); - q->ordseq |= seq; + BUG_ON(q->flush_seq & seq); + q->flush_seq |= seq; - if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) { - /* not complete yet, queue the next ordered sequence */ - next_rq = queue_next_ordseq(q); + if (blk_flush_cur_seq(q) != QUEUE_FSEQ_DONE) { + /* not complete yet, queue the next flush sequence */ + next_rq = queue_next_fseq(q); } else { - /* complete this barrier request */ - __blk_end_request_all(q->orig_bar_rq, q->orderr); - q->orig_bar_rq = NULL; - q->ordseq = 0; - - /* dispatch the next barrier if there's one */ - if (!list_empty(&q->pending_barriers)) { - next_rq = list_entry_rq(q->pending_barriers.next); + /* complete this flush request */ + __blk_end_request_all(q->orig_flush_rq, q->flush_err); + q->orig_flush_rq = NULL; + q->flush_seq = 0; + + /* dispatch the next flush if there's one */ + if (!list_empty(&q->pending_flushes)) { + next_rq = list_entry_rq(q->pending_flushes.next); list_move(&next_rq->queuelist, &q->queue_head); } } @@ -53,19 +50,19 @@ static struct request *blk_ordered_complete_seq(struct request_queue *q, static void pre_flush_end_io(struct request *rq, int error) { elv_completed_request(rq->q, rq); - blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error); + blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error); } -static void bar_end_io(struct request *rq, int error) +static void flush_data_end_io(struct request *rq, int error) { elv_completed_request(rq->q, rq); - blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error); + blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error); } static void post_flush_end_io(struct request *rq, int error) { elv_completed_request(rq->q, rq); - blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error); + blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error); } static void queue_flush(struct request_queue *q, struct request *rq, @@ -74,34 +71,34 @@ static void queue_flush(struct request_queue *q, struct request *rq, blk_rq_init(q, rq); rq->cmd_type = REQ_TYPE_FS; rq->cmd_flags = REQ_FLUSH; - rq->rq_disk = q->orig_bar_rq->rq_disk; + rq->rq_disk = q->orig_flush_rq->rq_disk; rq->end_io = end_io; elv_insert(q, rq, ELEVATOR_INSERT_FRONT); } -static struct request *queue_next_ordseq(struct request_queue *q) +static struct request *queue_next_fseq(struct request_queue *q) { - struct request *rq = &q->bar_rq; + struct request *rq = &q->flush_rq; - switch (blk_ordered_cur_seq(q)) { - case QUEUE_ORDSEQ_PREFLUSH: + switch (blk_flush_cur_seq(q)) { + case QUEUE_FSEQ_PREFLUSH: queue_flush(q, rq, pre_flush_end_io); break; - case QUEUE_ORDSEQ_BAR: + case QUEUE_FSEQ_DATA: /* initialize proxy request and queue it */ blk_rq_init(q, rq); - init_request_from_bio(rq, q->orig_bar_rq->bio); + 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; - rq->end_io = bar_end_io; + rq->end_io = flush_data_end_io; elv_insert(q, rq, ELEVATOR_INSERT_FRONT); break; - case QUEUE_ORDSEQ_POSTFLUSH: + case QUEUE_FSEQ_POSTFLUSH: queue_flush(q, rq, post_flush_end_io); break; @@ -111,19 +108,20 @@ static struct request *queue_next_ordseq(struct request_queue *q) return rq; } -struct request *blk_do_ordered(struct request_queue *q, struct request *rq) +struct request *blk_do_flush(struct request_queue *q, struct request *rq) { unsigned skip = 0; if (!(rq->cmd_flags & REQ_HARDBARRIER)) return rq; - if (q->ordseq) { + if (q->flush_seq) { /* - * Barrier is already in progress and they can't be - * processed in parallel. Queue for later processing. + * 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_barriers); + list_move_tail(&rq->queuelist, &q->pending_flushes); return NULL; } @@ -138,11 +136,11 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq) } /* - * Start a new ordered sequence + * Start a new flush sequence */ - q->orderr = 0; + q->flush_err = 0; q->ordered = q->next_ordered; - q->ordseq |= QUEUE_ORDSEQ_STARTED; + q->flush_seq |= QUEUE_FSEQ_STARTED; /* * For an empty barrier, there's no actual BAR request, which @@ -154,19 +152,19 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq) /* stash away the original request */ blk_dequeue_request(rq); - q->orig_bar_rq = rq; + q->orig_flush_rq = rq; if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) - skip |= QUEUE_ORDSEQ_PREFLUSH; + skip |= QUEUE_FSEQ_PREFLUSH; if (!(q->ordered & QUEUE_ORDERED_DO_BAR)) - skip |= QUEUE_ORDSEQ_BAR; + skip |= QUEUE_FSEQ_DATA; if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH)) - skip |= QUEUE_ORDSEQ_POSTFLUSH; + skip |= QUEUE_FSEQ_POSTFLUSH; /* complete skipped sequences and return the first sequence */ - return blk_ordered_complete_seq(q, skip, 0); + return blk_flush_complete_seq(q, skip, 0); } static void bio_end_empty_barrier(struct bio *bio, int err) diff --git a/block/blk.h b/block/blk.h index 08081e4..24b92bd 100644 --- a/block/blk.h +++ b/block/blk.h @@ -51,7 +51,7 @@ static inline void blk_clear_rq_complete(struct request *rq) */ #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) -struct request *blk_do_ordered(struct request_queue *q, struct request *rq); +struct request *blk_do_flush(struct request_queue *q, struct request *rq); static inline struct request *__elv_next_request(struct request_queue *q) { @@ -60,7 +60,7 @@ 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); - rq = blk_do_ordered(q, rq); + rq = blk_do_flush(q, rq); if (rq) return rq; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 522ecda..87e58f0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -357,13 +357,13 @@ struct request_queue /* * for flush operations */ + unsigned int ordered, next_ordered; unsigned int flush_flags; - - unsigned int ordered, next_ordered, ordseq; - int orderr; - struct request bar_rq; - struct request *orig_bar_rq; - struct list_head pending_barriers; + unsigned int flush_seq; + int flush_err; + struct request flush_rq; + struct request *orig_flush_rq; + struct list_head pending_flushes; struct mutex sysfs_lock; @@ -489,13 +489,13 @@ enum { QUEUE_ORDERED_DO_FUA, /* - * Ordered operation sequence + * FLUSH/FUA sequences. */ - QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */ - QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */ - QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */ - QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */ - QUEUE_ORDSEQ_DONE = (1 << 4), + 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), }; #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) @@ -507,7 +507,7 @@ enum { #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) #define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) #define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags) -#define blk_queue_flushing(q) ((q)->ordseq) +#define blk_queue_flushing(q) ((q)->flush_seq) #define blk_queue_stackable(q) \ test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) #define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |