diff options
| -rw-r--r-- | block/blk-core.c | 2 | ||||
| -rw-r--r-- | block/blk-flush.c | 85 | ||||
| -rw-r--r-- | block/blk.h | 3 | ||||
| -rw-r--r-- | include/linux/blk_types.h | 2 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 38 | ||||
| -rw-r--r-- | include/linux/buffer_head.h | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 19 |
7 files changed, 67 insertions, 84 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 8870ae4..18455c4 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 dd87322..452c552 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 24b92bd..a09c18b 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; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 9192282..1797994 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -167,7 +167,7 @@ enum rq_flag_bits { (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) #define REQ_COMMON_MASK \ (REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \ - REQ_META| REQ_DISCARD | REQ_NOIDLE) + REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA) #define REQ_UNPLUG (1 << __REQ_UNPLUG) #define REQ_RAHEAD (1 << __REQ_RAHEAD) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1cd83ec..8ef705f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -357,7 +357,6 @@ struct request_queue /* * for flush operations */ - unsigned int ordered, next_ordered; unsigned int flush_flags; unsigned int flush_seq; int flush_err; @@ -465,40 +464,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) __clear_bit(flag, &q->queue_flags); } -enum { - /* - * Hardbarrier is supported with one of the following methods. - * - * NONE : hardbarrier unsupported - * DRAIN : ordering by draining is enough - * DRAIN_FLUSH : ordering by draining w/ pre and post flushes - * DRAIN_FUA : ordering by draining w/ pre flush and FUA write - */ - QUEUE_ORDERED_DO_PREFLUSH = 0x10, - QUEUE_ORDERED_DO_BAR = 0x20, - QUEUE_ORDERED_DO_POSTFLUSH = 0x40, - QUEUE_ORDERED_DO_FUA = 0x80, - - QUEUE_ORDERED_NONE = 0x00, - - QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR, - QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | - QUEUE_ORDERED_DO_PREFLUSH | - QUEUE_ORDERED_DO_POSTFLUSH, - QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | - QUEUE_ORDERED_DO_PREFLUSH | - QUEUE_ORDERED_DO_FUA, - - /* - * FLUSH/FUA sequences. - */ - 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) #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) @@ -578,7 +543,8 @@ static inline void blk_clear_queue_full(struct request_queue *q, int sync) * it already be started by driver. */ #define RQ_NOMERGE_FLAGS \ - (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) + (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \ + REQ_FLUSH | REQ_FUA) #define rq_mergeable(rq) \ (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ (((rq)->cmd_flags & REQ_DISCARD) || \ diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index ec94c12..fc999f5 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -32,7 +32,7 @@ enum bh_state_bits { BH_Delay, /* Buffer is not yet allocated on disk */ BH_Boundary, /* Block is followed by a discontiguity */ BH_Write_EIO, /* I/O error on write */ - BH_Eopnotsupp, /* operation not supported (barrier) */ + BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */ BH_Unwritten, /* Buffer is allocated on disk but not written */ BH_Quiet, /* Buffer Error Prinks to be quiet */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 76041b6..352c486 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -135,12 +135,13 @@ struct inodes_stat_t { * immediately after submission. The write equivalent * of READ_SYNC. * WRITE_ODIRECT_PLUG Special case write for O_DIRECT only. - * WRITE_BARRIER Like WRITE_SYNC, but tells the block layer that all - * previously submitted writes must be safely on storage - * before this one is started. Also guarantees that when - * this write is complete, it itself is also safely on - * storage. Prevents reordering of writes on both sides - * of this IO. + * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead. + * WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush. + * WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on + * non-volatile media on completion. + * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded + * by a cache flush and data is guaranteed to be on + * non-volatile media on completion. * */ #define RW_MASK REQ_WRITE @@ -158,6 +159,12 @@ struct inodes_stat_t { #define WRITE_META (WRITE | REQ_META) #define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \ REQ_HARDBARRIER) +#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \ + REQ_FLUSH) +#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \ + REQ_FUA) +#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \ + REQ_FLUSH | REQ_FUA) /* * These aren't really reads or writes, they pass down information about |
