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block: rename barrier/ordered to flush

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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@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Tejun Heo
2010-09-03 11:56:16 +02:00
committed by Jens Axboe
parent 8839a0e055
commit dd4c133f38
4 changed files with 71 additions and 74 deletions
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21
block/blk-core.c
View File

@ -136,7 +136,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
{ {
struct request_queue *q = rq->q; struct request_queue *q = rq->q;
if (&q->bar_rq != rq) { if (&q->flush_rq != rq) {
if (error) if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags); clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_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) if (bio->bi_size == 0)
bio_endio(bio, error); bio_endio(bio, error);
} else { } else {
/* /*
* Okay, this is the barrier request in progress, just * Okay, this is the sequenced flush request in
* record the error; * progress, just record the error;
*/ */
if (error && !q->orderr) if (error && !q->flush_err)
q->orderr = error; 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); init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q); setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list); 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); INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype); kobject_init(&q->kobj, &blk_queue_ktype);
@ -1764,11 +1763,11 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
static void blk_account_io_done(struct request *req) static void blk_account_io_done(struct request *req)
{ {
/* /*
* Account IO completion. bar_rq isn't accounted as a normal * Account IO completion. flush_rq isn't accounted as a
* IO on queueing nor completion. Accounting the containing * normal IO on queueing nor completion. Accounting the
* request is enough. * 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; unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req); const int rw = rq_data_dir(req);
struct hd_struct *part; struct hd_struct *part;

96
block/blk-flush.c
View File

@ -9,41 +9,38 @@
#include "blk.h" #include "blk.h"
static struct request *queue_next_ordseq(struct request_queue *q); static struct request *queue_next_fseq(struct request_queue *q);
/* unsigned blk_flush_cur_seq(struct request_queue *q)
* Cache flushing for ordered writes handling
*/
unsigned blk_ordered_cur_seq(struct request_queue *q)
{ {
if (!q->ordseq) if (!q->flush_seq)
return 0; return 0;
return 1 << ffz(q->ordseq); return 1 << ffz(q->flush_seq);
} }
static struct request *blk_ordered_complete_seq(struct request_queue *q, static struct request *blk_flush_complete_seq(struct request_queue *q,
unsigned seq, int error) unsigned seq, int error)
{ {
struct request *next_rq = NULL; struct request *next_rq = NULL;
if (error && !q->orderr) if (error && !q->flush_err)
q->orderr = error; q->flush_err = error;
BUG_ON(q->ordseq & seq); BUG_ON(q->flush_seq & seq);
q->ordseq |= seq; q->flush_seq |= seq;
if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) { if (blk_flush_cur_seq(q) != QUEUE_FSEQ_DONE) {
/* not complete yet, queue the next ordered sequence */ /* not complete yet, queue the next flush sequence */
next_rq = queue_next_ordseq(q); next_rq = queue_next_fseq(q);
} else { } else {
/* complete this barrier request */ /* complete this flush request */
__blk_end_request_all(q->orig_bar_rq, q->orderr); __blk_end_request_all(q->orig_flush_rq, q->flush_err);
q->orig_bar_rq = NULL; q->orig_flush_rq = NULL;
q->ordseq = 0; q->flush_seq = 0;
/* dispatch the next barrier if there's one */ /* dispatch the next flush if there's one */
if (!list_empty(&q->pending_barriers)) { if (!list_empty(&q->pending_flushes)) {
next_rq = list_entry_rq(q->pending_barriers.next); next_rq = list_entry_rq(q->pending_flushes.next);
list_move(&next_rq->queuelist, &q->queue_head); 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) static void pre_flush_end_io(struct request *rq, int error)
{ {
elv_completed_request(rq->q, rq); 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); 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) static void post_flush_end_io(struct request *rq, int error)
{ {
elv_completed_request(rq->q, rq); 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, 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); blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS; rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH; 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; rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT); 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)) { switch (blk_flush_cur_seq(q)) {
case QUEUE_ORDSEQ_PREFLUSH: case QUEUE_FSEQ_PREFLUSH:
queue_flush(q, rq, pre_flush_end_io); queue_flush(q, rq, pre_flush_end_io);
break; break;
case QUEUE_ORDSEQ_BAR: case QUEUE_FSEQ_DATA:
/* initialize proxy request and queue it */ /* initialize proxy request and queue it */
blk_rq_init(q, rq); 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; rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA) if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_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); elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break; break;
case QUEUE_ORDSEQ_POSTFLUSH: case QUEUE_FSEQ_POSTFLUSH:
queue_flush(q, rq, post_flush_end_io); queue_flush(q, rq, post_flush_end_io);
break; break;
@ -111,19 +108,20 @@ static struct request *queue_next_ordseq(struct request_queue *q)
return rq; 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; unsigned skip = 0;
if (!(rq->cmd_flags & REQ_HARDBARRIER)) if (!(rq->cmd_flags & REQ_HARDBARRIER))
return rq; return rq;
if (q->ordseq) { if (q->flush_seq) {
/* /*
* Barrier is already in progress and they can't be * Sequenced flush is already in progress and they
* processed in parallel. Queue for later processing. * 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; 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->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 * 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 */ /* stash away the original request */
blk_dequeue_request(rq); blk_dequeue_request(rq);
q->orig_bar_rq = rq; q->orig_flush_rq = rq;
if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
skip |= QUEUE_ORDSEQ_PREFLUSH; skip |= QUEUE_FSEQ_PREFLUSH;
if (!(q->ordered & QUEUE_ORDERED_DO_BAR)) if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
skip |= QUEUE_ORDSEQ_BAR; skip |= QUEUE_FSEQ_DATA;
if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH)) if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
skip |= QUEUE_ORDSEQ_POSTFLUSH; skip |= QUEUE_FSEQ_POSTFLUSH;
/* complete skipped sequences and return the first sequence */ /* 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) static void bio_end_empty_barrier(struct bio *bio, int err)

4
block/blk.h
View File

@ -51,7 +51,7 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/ */
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) #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) 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 (1) {
while (!list_empty(&q->queue_head)) { while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next); rq = list_entry_rq(q->queue_head.next);
rq = blk_do_ordered(q, rq); rq = blk_do_flush(q, rq);
if (rq) if (rq)
return rq; return rq;
} }

24
include/linux/blkdev.h
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@ -357,13 +357,13 @@ struct request_queue
/* /*
* for flush operations * for flush operations
*/ */
unsigned int ordered, next_ordered;
unsigned int flush_flags; unsigned int flush_flags;
unsigned int flush_seq;
unsigned int ordered, next_ordered, ordseq; int flush_err;
int orderr; struct request flush_rq;
struct request bar_rq; struct request *orig_flush_rq;
struct request *orig_bar_rq; struct list_head pending_flushes;
struct list_head pending_barriers;
struct mutex sysfs_lock; struct mutex sysfs_lock;
@ -490,13 +490,13 @@ enum {
QUEUE_ORDERED_DO_FUA, QUEUE_ORDERED_DO_FUA,
/* /*
* Ordered operation sequence * FLUSH/FUA sequences.
*/ */
QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
QUEUE_ORDSEQ_DONE = (1 << 4), QUEUE_FSEQ_DONE = (1 << 4),
}; };
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)