From 0da2f50944976e890ccc9436ab88c0da87788d02 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:16 +0200 Subject: ide: remove unnecessary blk_queue_flushing() test in do_ide_request() Unplugging from a request function doesn't really help much (it's already in the request_fn) and soon block layer will be updated to mix barrier sequence with other commands, so there's no need to treat queue flushing any differently. ide was the only user of blk_queue_flushing(). Remove it. Signed-off-by: Tejun Heo Cc: Christoph Hellwig Acked-by: David S. Miller Signed-off-by: Jens Axboe --- drivers/ide/ide-io.c | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'drivers') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index a381be8..999dac0 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -441,19 +441,6 @@ void do_ide_request(struct request_queue *q) struct request *rq = NULL; ide_startstop_t startstop; - /* - * drive is doing pre-flush, ordered write, post-flush sequence. even - * though that is 3 requests, it must be seen as a single transaction. - * we must not preempt this drive until that is complete - */ - if (blk_queue_flushing(q)) - /* - * small race where queue could get replugged during - * the 3-request flush cycle, just yank the plug since - * we want it to finish asap - */ - blk_remove_plug(q); - spin_unlock_irq(q->queue_lock); /* HLD do_request() callback might sleep, make sure it's okay */ -- cgit v1.1 From 589d7ed02ade0d06a3510da2e15a7edfdb2ef3d8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:16 +0200 Subject: block/loop: queue ordered mode should be DRAIN_FLUSH loop implements FLUSH using fsync but was incorrectly setting its ordered mode to DRAIN. Change it to DRAIN_FLUSH. In practice, this doesn't change anything as loop doesn't make use of the block layer ordered implementation. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- drivers/block/loop.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index f3c636d..c3a4a2e 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, lo->lo_queue->unplug_fn = loop_unplug; if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) - blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN); + blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH); set_capacity(lo->lo_disk, size); bd_set_size(bdev, size << 9); -- cgit v1.1 From 6958f145459ca7ad9715024de97445addacb8510 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:16 +0200 Subject: block: kill QUEUE_ORDERED_BY_TAG Nobody is making meaningful use of ORDERED_BY_TAG now and queue draining for barrier requests will be removed soon which will render the advantage of tag ordering moot. Kill ORDERED_BY_TAG. The following users are affected. * brd: converted to ORDERED_DRAIN. * virtio_blk: ORDERED_TAG path was already marked deprecated. Removed. * xen-blkfront: ORDERED_TAG case dropped. Signed-off-by: Tejun Heo Cc: Christoph Hellwig Cc: Nick Piggin Cc: Michael S. Tsirkin Cc: Jeremy Fitzhardinge Cc: Chris Wright Signed-off-by: Jens Axboe --- drivers/block/brd.c | 2 +- drivers/block/virtio_blk.c | 9 --------- drivers/block/xen-blkfront.c | 8 +++----- drivers/scsi/sd.c | 4 +--- 4 files changed, 5 insertions(+), 18 deletions(-) (limited to 'drivers') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 1c7f637..47a4127 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -482,7 +482,7 @@ static struct brd_device *brd_alloc(int i) if (!brd->brd_queue) goto out_free_dev; blk_queue_make_request(brd->brd_queue, brd_make_request); - blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG); + blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN); blk_queue_max_hw_sectors(brd->brd_queue, 1024); blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY); diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 2aafafc..7965280 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -395,15 +395,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) * to implement write barrier support. */ blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH); - } else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) { - /* - * If the BARRIER feature is supported the host expects us - * to order request by tags. This implies there is not - * volatile write cache on the host, and that the host - * never re-orders outstanding I/O. This feature is not - * useful for real life scenarious and deprecated. - */ - blk_queue_ordered(q, QUEUE_ORDERED_TAG); } else { /* * If the FLUSH feature is not supported we must assume that diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index ac1b682..50ec6f8 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -424,8 +424,7 @@ static int xlvbd_barrier(struct blkfront_info *info) const char *barrier; switch (info->feature_barrier) { - case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break; - case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break; + case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break; case QUEUE_ORDERED_NONE: barrier = "disabled"; break; default: return -EINVAL; } @@ -1078,8 +1077,7 @@ static void blkfront_connect(struct blkfront_info *info) * we're dealing with a very old backend which writes * synchronously; draining will do what needs to get done. * - * If there are barriers, then we can do full queued writes - * with tagged barriers. + * If there are barriers, then we use flush. * * If barriers are not supported, then there's no much we can * do, so just set ordering to NONE. @@ -1087,7 +1085,7 @@ static void blkfront_connect(struct blkfront_info *info) if (err) info->feature_barrier = QUEUE_ORDERED_DRAIN; else if (barrier) - info->feature_barrier = QUEUE_ORDERED_TAG; + info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH; else info->feature_barrier = QUEUE_ORDERED_NONE; diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 2714bec..cdfc51a 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2151,9 +2151,7 @@ static int sd_revalidate_disk(struct gendisk *disk) /* * We now have all cache related info, determine how we deal - * with ordered requests. Note that as the current SCSI - * dispatch function can alter request order, we cannot use - * QUEUE_ORDERED_TAG_* even when ordered tag is supported. + * with ordered requests. */ if (sdkp->WCE) ordered = sdkp->DPOFUA -- cgit v1.1 From 4913efe456c987057e5d36a3f0a55422a9072cae Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:16 +0200 Subject: block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush() Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with -EOPNOTSUPP and blk_queue_ordered() is replaced with simpler blk_queue_flush(). blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a device has write cache and can flush it, it should set REQ_FLUSH. If the device can handle FUA writes, it should also set REQ_FUA. All blk_queue_ordered() users are converted. * ORDERED_DRAIN is mapped to 0 which is the default value. * ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH. * ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA. Signed-off-by: Tejun Heo Acked-by: Boaz Harrosh Cc: Christoph Hellwig Cc: Nick Piggin Cc: Michael S. Tsirkin Cc: Jeremy Fitzhardinge Cc: Chris Wright Cc: FUJITA Tomonori Cc: Geert Uytterhoeven Cc: David S. Miller Cc: Alasdair G Kergon Cc: Pierre Ossman Cc: Stefan Weinhuber Signed-off-by: Jens Axboe --- drivers/block/brd.c | 1 - drivers/block/loop.c | 2 +- drivers/block/osdblk.c | 2 +- drivers/block/ps3disk.c | 2 +- drivers/block/virtio_blk.c | 25 +++++++++---------------- drivers/block/xen-blkfront.c | 43 ++++++++++++------------------------------- drivers/ide/ide-disk.c | 13 ++++++------- drivers/md/dm.c | 2 +- drivers/mmc/card/queue.c | 1 - drivers/s390/block/dasd.c | 1 - drivers/scsi/sd.c | 16 ++++++++-------- 11 files changed, 39 insertions(+), 69 deletions(-) (limited to 'drivers') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 47a4127..fa33f97 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -482,7 +482,6 @@ static struct brd_device *brd_alloc(int i) if (!brd->brd_queue) goto out_free_dev; blk_queue_make_request(brd->brd_queue, brd_make_request); - blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN); blk_queue_max_hw_sectors(brd->brd_queue, 1024); blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY); diff --git a/drivers/block/loop.c b/drivers/block/loop.c index c3a4a2e..953d1e1 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, lo->lo_queue->unplug_fn = loop_unplug; if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) - blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH); + blk_queue_flush(lo->lo_queue, REQ_FLUSH); set_capacity(lo->lo_disk, size); bd_set_size(bdev, size << 9); diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c index 2284b4f..72d6246 100644 --- a/drivers/block/osdblk.c +++ b/drivers/block/osdblk.c @@ -439,7 +439,7 @@ static int osdblk_init_disk(struct osdblk_device *osdev) blk_queue_stack_limits(q, osd_request_queue(osdev->osd)); blk_queue_prep_rq(q, blk_queue_start_tag); - blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH); + blk_queue_flush(q, REQ_FLUSH); disk->queue = q; diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c index e9da874..4911f9e 100644 --- a/drivers/block/ps3disk.c +++ b/drivers/block/ps3disk.c @@ -468,7 +468,7 @@ static int __devinit ps3disk_probe(struct ps3_system_bus_device *_dev) blk_queue_dma_alignment(queue, dev->blk_size-1); blk_queue_logical_block_size(queue, dev->blk_size); - blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH); + blk_queue_flush(queue, REQ_FLUSH); blk_queue_max_segments(queue, -1); blk_queue_max_segment_size(queue, dev->bounce_size); diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 7965280..d10b635 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -388,22 +388,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) vblk->disk->driverfs_dev = &vdev->dev; index++; - if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) { - /* - * If the FLUSH feature is supported we do have support for - * flushing a volatile write cache on the host. Use that - * to implement write barrier support. - */ - blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH); - } else { - /* - * If the FLUSH feature is not supported we must assume that - * the host does not perform any kind of volatile write - * caching. We still need to drain the queue to provider - * proper barrier semantics. - */ - blk_queue_ordered(q, QUEUE_ORDERED_DRAIN); - } + /* + * If the FLUSH feature is supported we do have support for + * flushing a volatile write cache on the host. Use that to + * implement write barrier support; otherwise, we must assume + * that the host does not perform any kind of volatile write + * caching. + */ + if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) + blk_queue_flush(q, REQ_FLUSH); /* If disk is read-only in the host, the guest should obey */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 50ec6f8..0b1eea6 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -95,7 +95,7 @@ struct blkfront_info struct gnttab_free_callback callback; struct blk_shadow shadow[BLK_RING_SIZE]; unsigned long shadow_free; - int feature_barrier; + unsigned int feature_flush; int is_ready; }; @@ -418,25 +418,12 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size) } -static int xlvbd_barrier(struct blkfront_info *info) +static void xlvbd_flush(struct blkfront_info *info) { - int err; - const char *barrier; - - switch (info->feature_barrier) { - case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break; - case QUEUE_ORDERED_NONE: barrier = "disabled"; break; - default: return -EINVAL; - } - - err = blk_queue_ordered(info->rq, info->feature_barrier); - - if (err) - return err; - + blk_queue_flush(info->rq, info->feature_flush); printk(KERN_INFO "blkfront: %s: barriers %s\n", - info->gd->disk_name, barrier); - return 0; + info->gd->disk_name, + info->feature_flush ? "enabled" : "disabled"); } @@ -515,7 +502,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, info->rq = gd->queue; info->gd = gd; - xlvbd_barrier(info); + xlvbd_flush(info); if (vdisk_info & VDISK_READONLY) set_disk_ro(gd, 1); @@ -661,8 +648,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) printk(KERN_WARNING "blkfront: %s: write barrier op failed\n", info->gd->disk_name); error = -EOPNOTSUPP; - info->feature_barrier = QUEUE_ORDERED_NONE; - xlvbd_barrier(info); + info->feature_flush = 0; + xlvbd_flush(info); } /* fall through */ case BLKIF_OP_READ: @@ -1075,19 +1062,13 @@ static void blkfront_connect(struct blkfront_info *info) /* * If there's no "feature-barrier" defined, then it means * we're dealing with a very old backend which writes - * synchronously; draining will do what needs to get done. + * synchronously; nothing to do. * * If there are barriers, then we use flush. - * - * If barriers are not supported, then there's no much we can - * do, so just set ordering to NONE. */ - if (err) - info->feature_barrier = QUEUE_ORDERED_DRAIN; - else if (barrier) - info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH; - else - info->feature_barrier = QUEUE_ORDERED_NONE; + info->feature_flush = 0; + if (!err && barrier) + info->feature_flush = REQ_FLUSH; err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size); if (err) { diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c index 7433e07..7c5b01c 100644 --- a/drivers/ide/ide-disk.c +++ b/drivers/ide/ide-disk.c @@ -516,10 +516,10 @@ static int ide_do_setfeature(ide_drive_t *drive, u8 feature, u8 nsect) return ide_no_data_taskfile(drive, &cmd); } -static void update_ordered(ide_drive_t *drive) +static void update_flush(ide_drive_t *drive) { u16 *id = drive->id; - unsigned ordered = QUEUE_ORDERED_NONE; + unsigned flush = 0; if (drive->dev_flags & IDE_DFLAG_WCACHE) { unsigned long long capacity; @@ -543,13 +543,12 @@ static void update_ordered(ide_drive_t *drive) drive->name, barrier ? "" : "not "); if (barrier) { - ordered = QUEUE_ORDERED_DRAIN_FLUSH; + flush = REQ_FLUSH; blk_queue_prep_rq(drive->queue, idedisk_prep_fn); } - } else - ordered = QUEUE_ORDERED_DRAIN; + } - blk_queue_ordered(drive->queue, ordered); + blk_queue_flush(drive->queue, flush); } ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE); @@ -572,7 +571,7 @@ static int set_wcache(ide_drive_t *drive, int arg) } } - update_ordered(drive); + update_flush(drive); return err; } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ac384b2..b1d92be 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2245,7 +2245,7 @@ static int dm_init_request_based_queue(struct mapped_device *md) blk_queue_softirq_done(md->queue, dm_softirq_done); blk_queue_prep_rq(md->queue, dm_prep_fn); blk_queue_lld_busy(md->queue, dm_lld_busy); - blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH); + blk_queue_flush(md->queue, REQ_FLUSH); elv_register_queue(md->queue); diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index e876678..9c0b42b 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -128,7 +128,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock mq->req = NULL; blk_queue_prep_rq(mq->queue, mmc_prep_request); - blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); if (mmc_can_erase(card)) { queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue); diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 8373ca0..9b106d8 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2197,7 +2197,6 @@ static void dasd_setup_queue(struct dasd_block *block) */ blk_queue_max_segment_size(block->request_queue, PAGE_SIZE); blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1); - blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN); } /* diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index cdfc51a..63bd01a 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2109,7 +2109,7 @@ static int sd_revalidate_disk(struct gendisk *disk) struct scsi_disk *sdkp = scsi_disk(disk); struct scsi_device *sdp = sdkp->device; unsigned char *buffer; - unsigned ordered; + unsigned flush = 0; SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_revalidate_disk\n")); @@ -2151,15 +2151,15 @@ static int sd_revalidate_disk(struct gendisk *disk) /* * We now have all cache related info, determine how we deal - * with ordered requests. + * with flush requests. */ - if (sdkp->WCE) - ordered = sdkp->DPOFUA - ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH; - else - ordered = QUEUE_ORDERED_DRAIN; + if (sdkp->WCE) { + flush |= REQ_FLUSH; + if (sdkp->DPOFUA) + flush |= REQ_FUA; + } - blk_queue_ordered(sdkp->disk->queue, ordered); + blk_queue_flush(sdkp->disk->queue, flush); set_capacity(disk, sdkp->capacity); kfree(buffer); -- cgit v1.1 From 9cbbdca44ae1a6f512ea1e2be11ced8bbb9d430a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:16 +0200 Subject: block: remove spurious uses of REQ_HARDBARRIER REQ_HARDBARRIER is deprecated. Remove spurious uses in the following users. Please note that other than osdblk, all other uses were already spurious before deprecation. * osdblk: osdblk_rq_fn() won't receive any request with REQ_HARDBARRIER set. Remove the test for it. * pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean anything. Removed. * aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is spurious. Removed. * sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is spurious. Removed. * scsi_tcq: The ordered tag path wasn't being used anyway. Removed. Signed-off-by: Tejun Heo Acked-by: Boaz Harrosh Cc: James Bottomley Cc: Peter Osterlund Signed-off-by: Jens Axboe --- drivers/block/osdblk.c | 3 +-- drivers/block/pktcdvd.c | 1 - drivers/scsi/aic7xxx_old.c | 21 ++------------------- drivers/scsi/libsas/sas_scsi_host.c | 13 +------------ 4 files changed, 4 insertions(+), 34 deletions(-) (limited to 'drivers') diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c index 72d6246..87311eb 100644 --- a/drivers/block/osdblk.c +++ b/drivers/block/osdblk.c @@ -310,8 +310,7 @@ static void osdblk_rq_fn(struct request_queue *q) break; /* filter out block requests we don't understand */ - if (rq->cmd_type != REQ_TYPE_FS && - !(rq->cmd_flags & REQ_HARDBARRIER)) { + if (rq->cmd_type != REQ_TYPE_FS) { blk_end_request_all(rq, 0); continue; } diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index b1cbeb5..0166ea13 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -753,7 +753,6 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command * rq->timeout = 60*HZ; rq->cmd_type = REQ_TYPE_BLOCK_PC; - rq->cmd_flags |= REQ_HARDBARRIER; if (cgc->quiet) rq->cmd_flags |= REQ_QUIET; diff --git a/drivers/scsi/aic7xxx_old.c b/drivers/scsi/aic7xxx_old.c index 93984c9..e1cd606 100644 --- a/drivers/scsi/aic7xxx_old.c +++ b/drivers/scsi/aic7xxx_old.c @@ -2850,12 +2850,6 @@ aic7xxx_done(struct aic7xxx_host *p, struct aic7xxx_scb *scb) aic_dev->r_total++; ptr = aic_dev->r_bins; } - if(cmd->device->simple_tags && cmd->request->cmd_flags & REQ_HARDBARRIER) - { - aic_dev->barrier_total++; - if(scb->tag_action == MSG_ORDERED_Q_TAG) - aic_dev->ordered_total++; - } x = scb->sg_length; x >>= 10; for(i=0; i<6; i++) @@ -10144,19 +10138,8 @@ static void aic7xxx_buildscb(struct aic7xxx_host *p, struct scsi_cmnd *cmd, /* We always force TEST_UNIT_READY to untagged */ if (cmd->cmnd[0] != TEST_UNIT_READY && sdptr->simple_tags) { - if (req->cmd_flags & REQ_HARDBARRIER) - { - if(sdptr->ordered_tags) - { - hscb->control |= MSG_ORDERED_Q_TAG; - scb->tag_action = MSG_ORDERED_Q_TAG; - } - } - else - { - hscb->control |= MSG_SIMPLE_Q_TAG; - scb->tag_action = MSG_SIMPLE_Q_TAG; - } + hscb->control |= MSG_SIMPLE_Q_TAG; + scb->tag_action = MSG_SIMPLE_Q_TAG; } } if ( !(aic_dev->dtr_pending) && diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c index f0cfba9..535085c 100644 --- a/drivers/scsi/libsas/sas_scsi_host.c +++ b/drivers/scsi/libsas/sas_scsi_host.c @@ -130,17 +130,6 @@ static void sas_scsi_task_done(struct sas_task *task) sc->scsi_done(sc); } -static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd) -{ - enum task_attribute ta = TASK_ATTR_SIMPLE; - if (cmd->request && blk_rq_tagged(cmd->request)) { - if (cmd->device->ordered_tags && - (cmd->request->cmd_flags & REQ_HARDBARRIER)) - ta = TASK_ATTR_ORDERED; - } - return ta; -} - static struct sas_task *sas_create_task(struct scsi_cmnd *cmd, struct domain_device *dev, gfp_t gfp_flags) @@ -160,7 +149,7 @@ static struct sas_task *sas_create_task(struct scsi_cmnd *cmd, task->ssp_task.retry_count = 1; int_to_scsilun(cmd->device->lun, &lun); memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8); - task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd); + task->ssp_task.task_attr = TASK_ATTR_SIMPLE; memcpy(task->ssp_task.cdb, cmd->cmnd, 16); task->scatter = scsi_sglist(cmd); -- cgit v1.1 From 6259f28459a9de820f47a9ece4ffa22d4596a9af Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:17 +0200 Subject: block/loop: implement REQ_FLUSH/FUA support Deprecate REQ_HARDBARRIER and implement REQ_FLUSH/FUA instead. Also, instead of checking file->f_op->fsync() directly, look at the value of vfs_fsync() and ignore -EINVAL return. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- drivers/block/loop.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 953d1e1..5d27bc6 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -477,17 +477,17 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset; if (bio_rw(bio) == WRITE) { - bool barrier = (bio->bi_rw & REQ_HARDBARRIER); struct file *file = lo->lo_backing_file; - if (barrier) { - if (unlikely(!file->f_op->fsync)) { - ret = -EOPNOTSUPP; - goto out; - } + /* REQ_HARDBARRIER is deprecated */ + if (bio->bi_rw & REQ_HARDBARRIER) { + ret = -EOPNOTSUPP; + goto out; + } + if (bio->bi_rw & REQ_FLUSH) { ret = vfs_fsync(file, 0); - if (unlikely(ret)) { + if (unlikely(ret && ret != -EINVAL)) { ret = -EIO; goto out; } @@ -495,9 +495,9 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) ret = lo_send(lo, bio, pos); - if (barrier && !ret) { + if ((bio->bi_rw & REQ_FUA) && !ret) { ret = vfs_fsync(file, 0); - if (unlikely(ret)) + if (unlikely(ret && ret != -EINVAL)) ret = -EIO; } } else -- cgit v1.1 From 02c42b7a68695c2c3e3fecf9f6b9a4ea43abe52f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:18 +0200 Subject: virtio_blk: drop REQ_HARDBARRIER support Remove now unused REQ_HARDBARRIER support. virtio_blk already supports REQ_FLUSH and the usefulness of REQ_FUA for virtio_blk is questionable at this point, so there's nothing else to do to support new REQ_FLUSH/FUA interface. Signed-off-by: Tejun Heo Cc: Michael S. Tsirkin Cc: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/virtio_blk.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) (limited to 'drivers') diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index d10b635..1260628 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -128,9 +128,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, } } - if (vbr->req->cmd_flags & REQ_HARDBARRIER) - vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER; - sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); /* @@ -388,13 +385,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) vblk->disk->driverfs_dev = &vdev->dev; index++; - /* - * If the FLUSH feature is supported we do have support for - * flushing a volatile write cache on the host. Use that to - * implement write barrier support; otherwise, we must assume - * that the host does not perform any kind of volatile write - * caching. - */ + /* configure queue flush support */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) blk_queue_flush(q, REQ_FLUSH); @@ -515,9 +506,9 @@ static const struct virtio_device_id id_table[] = { }; static unsigned int features[] = { - VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, - VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, - VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY + VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, + VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI, + VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY }; /* -- cgit v1.1 From e9c7469bb4f502dafc092166201bea1ad5fc0fbf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:18 +0200 Subject: md: implment REQ_FLUSH/FUA support This patch converts md to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. In the core part (md.c), the following changes are notable. * Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with processing of other requests and thus there is no reason to mark the queue congested while FLUSH/FUA is in progress. * REQ_FLUSH/FUA failures are final and its users don't need retry logic. Retry logic is removed. * Preflush needs to be issued to all member devices but FUA writes can be handled the same way as other writes - their processing can be deferred to request_queue of member devices. md_barrier_request() is renamed to md_flush_request() and simplified accordingly. For linear, raid0 and multipath, the core changes are enough. raid1, 5 and 10 need the following conversions. * raid1: Handling of FLUSH/FUA bio's can simply be deferred to request_queues of member devices. Barrier related logic removed. * raid5: Queue draining logic dropped. FUA bit is propagated through biodrain and stripe resconstruction such that all the updated parts of the stripe are written out with FUA writes if any of the dirtying writes was FUA. preread_active_stripes handling in make_request() is updated as suggested by Neil Brown. * raid10: FUA bit needs to be propagated to write clones. linear, raid0, 1, 5 and 10 tested. Signed-off-by: Tejun Heo Reviewed-by: Neil Brown Signed-off-by: Jens Axboe --- drivers/md/linear.c | 4 +- drivers/md/md.c | 117 +++++++------------------------- drivers/md/md.h | 23 ++----- drivers/md/multipath.c | 4 +- drivers/md/raid0.c | 4 +- drivers/md/raid1.c | 176 +++++++++++++++++-------------------------------- drivers/md/raid1.h | 2 - drivers/md/raid10.c | 7 +- drivers/md/raid5.c | 43 ++++++------ drivers/md/raid5.h | 1 + 10 files changed, 122 insertions(+), 259 deletions(-) (limited to 'drivers') diff --git a/drivers/md/linear.c b/drivers/md/linear.c index ba19060..8a2f767 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -294,8 +294,8 @@ static int linear_make_request (mddev_t *mddev, struct bio *bio) dev_info_t *tmp_dev; sector_t start_sector; - if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) { - md_barrier_request(mddev, bio); + if (unlikely(bio->bi_rw & REQ_FLUSH)) { + md_flush_request(mddev, bio); return 0; } diff --git a/drivers/md/md.c b/drivers/md/md.c index c148b63..3640f02 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -226,12 +226,12 @@ static int md_make_request(struct request_queue *q, struct bio *bio) return 0; } rcu_read_lock(); - if (mddev->suspended || mddev->barrier) { + if (mddev->suspended) { DEFINE_WAIT(__wait); for (;;) { prepare_to_wait(&mddev->sb_wait, &__wait, TASK_UNINTERRUPTIBLE); - if (!mddev->suspended && !mddev->barrier) + if (!mddev->suspended) break; rcu_read_unlock(); schedule(); @@ -282,40 +282,29 @@ EXPORT_SYMBOL_GPL(mddev_resume); int mddev_congested(mddev_t *mddev, int bits) { - if (mddev->barrier) - return 1; return mddev->suspended; } EXPORT_SYMBOL(mddev_congested); /* - * Generic barrier handling for md + * Generic flush handling for md */ -#define POST_REQUEST_BARRIER ((void*)1) - -static void md_end_barrier(struct bio *bio, int err) +static void md_end_flush(struct bio *bio, int err) { mdk_rdev_t *rdev = bio->bi_private; mddev_t *mddev = rdev->mddev; - if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER) - set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags); rdev_dec_pending(rdev, mddev); if (atomic_dec_and_test(&mddev->flush_pending)) { - if (mddev->barrier == POST_REQUEST_BARRIER) { - /* This was a post-request barrier */ - mddev->barrier = NULL; - wake_up(&mddev->sb_wait); - } else - /* The pre-request barrier has finished */ - schedule_work(&mddev->barrier_work); + /* The pre-request flush has finished */ + schedule_work(&mddev->flush_work); } bio_put(bio); } -static void submit_barriers(mddev_t *mddev) +static void submit_flushes(mddev_t *mddev) { mdk_rdev_t *rdev; @@ -332,60 +321,56 @@ static void submit_barriers(mddev_t *mddev) atomic_inc(&rdev->nr_pending); rcu_read_unlock(); bi = bio_alloc(GFP_KERNEL, 0); - bi->bi_end_io = md_end_barrier; + bi->bi_end_io = md_end_flush; bi->bi_private = rdev; bi->bi_bdev = rdev->bdev; atomic_inc(&mddev->flush_pending); - submit_bio(WRITE_BARRIER, bi); + submit_bio(WRITE_FLUSH, bi); rcu_read_lock(); rdev_dec_pending(rdev, mddev); } rcu_read_unlock(); } -static void md_submit_barrier(struct work_struct *ws) +static void md_submit_flush_data(struct work_struct *ws) { - mddev_t *mddev = container_of(ws, mddev_t, barrier_work); - struct bio *bio = mddev->barrier; + mddev_t *mddev = container_of(ws, mddev_t, flush_work); + struct bio *bio = mddev->flush_bio; atomic_set(&mddev->flush_pending, 1); - if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) - bio_endio(bio, -EOPNOTSUPP); - else if (bio->bi_size == 0) + if (bio->bi_size == 0) /* an empty barrier - all done */ bio_endio(bio, 0); else { - bio->bi_rw &= ~REQ_HARDBARRIER; + bio->bi_rw &= ~REQ_FLUSH; if (mddev->pers->make_request(mddev, bio)) generic_make_request(bio); - mddev->barrier = POST_REQUEST_BARRIER; - submit_barriers(mddev); } if (atomic_dec_and_test(&mddev->flush_pending)) { - mddev->barrier = NULL; + mddev->flush_bio = NULL; wake_up(&mddev->sb_wait); } } -void md_barrier_request(mddev_t *mddev, struct bio *bio) +void md_flush_request(mddev_t *mddev, struct bio *bio) { spin_lock_irq(&mddev->write_lock); wait_event_lock_irq(mddev->sb_wait, - !mddev->barrier, + !mddev->flush_bio, mddev->write_lock, /*nothing*/); - mddev->barrier = bio; + mddev->flush_bio = bio; spin_unlock_irq(&mddev->write_lock); atomic_set(&mddev->flush_pending, 1); - INIT_WORK(&mddev->barrier_work, md_submit_barrier); + INIT_WORK(&mddev->flush_work, md_submit_flush_data); - submit_barriers(mddev); + submit_flushes(mddev); if (atomic_dec_and_test(&mddev->flush_pending)) - schedule_work(&mddev->barrier_work); + schedule_work(&mddev->flush_work); } -EXPORT_SYMBOL(md_barrier_request); +EXPORT_SYMBOL(md_flush_request); /* Support for plugging. * This mirrors the plugging support in request_queue, but does not @@ -696,31 +681,6 @@ static void super_written(struct bio *bio, int error) bio_put(bio); } -static void super_written_barrier(struct bio *bio, int error) -{ - struct bio *bio2 = bio->bi_private; - mdk_rdev_t *rdev = bio2->bi_private; - mddev_t *mddev = rdev->mddev; - - if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && - error == -EOPNOTSUPP) { - unsigned long flags; - /* barriers don't appear to be supported :-( */ - set_bit(BarriersNotsupp, &rdev->flags); - mddev->barriers_work = 0; - spin_lock_irqsave(&mddev->write_lock, flags); - bio2->bi_next = mddev->biolist; - mddev->biolist = bio2; - spin_unlock_irqrestore(&mddev->write_lock, flags); - wake_up(&mddev->sb_wait); - bio_put(bio); - } else { - bio_put(bio2); - bio->bi_private = rdev; - super_written(bio, error); - } -} - void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev, sector_t sector, int size, struct page *page) { @@ -729,51 +689,28 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev, * and decrement it on completion, waking up sb_wait * if zero is reached. * If an error occurred, call md_error - * - * As we might need to resubmit the request if REQ_HARDBARRIER - * causes ENOTSUPP, we allocate a spare bio... */ struct bio *bio = bio_alloc(GFP_NOIO, 1); - int rw = REQ_WRITE | REQ_SYNC | REQ_UNPLUG; bio->bi_bdev = rdev->bdev; bio->bi_sector = sector; bio_add_page(bio, page, size, 0); bio->bi_private = rdev; bio->bi_end_io = super_written; - bio->bi_rw = rw; atomic_inc(&mddev->pending_writes); - if (!test_bit(BarriersNotsupp, &rdev->flags)) { - struct bio *rbio; - rw |= REQ_HARDBARRIER; - rbio = bio_clone(bio, GFP_NOIO); - rbio->bi_private = bio; - rbio->bi_end_io = super_written_barrier; - submit_bio(rw, rbio); - } else - submit_bio(rw, bio); + submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA, + bio); } void md_super_wait(mddev_t *mddev) { - /* wait for all superblock writes that were scheduled to complete. - * if any had to be retried (due to BARRIER problems), retry them - */ + /* wait for all superblock writes that were scheduled to complete */ DEFINE_WAIT(wq); for(;;) { prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE); if (atomic_read(&mddev->pending_writes)==0) break; - while (mddev->biolist) { - struct bio *bio; - spin_lock_irq(&mddev->write_lock); - bio = mddev->biolist; - mddev->biolist = bio->bi_next ; - bio->bi_next = NULL; - spin_unlock_irq(&mddev->write_lock); - submit_bio(bio->bi_rw, bio); - } schedule(); } finish_wait(&mddev->sb_wait, &wq); @@ -1070,7 +1007,6 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev) clear_bit(Faulty, &rdev->flags); clear_bit(In_sync, &rdev->flags); clear_bit(WriteMostly, &rdev->flags); - clear_bit(BarriersNotsupp, &rdev->flags); if (mddev->raid_disks == 0) { mddev->major_version = 0; @@ -1485,7 +1421,6 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev) clear_bit(Faulty, &rdev->flags); clear_bit(In_sync, &rdev->flags); clear_bit(WriteMostly, &rdev->flags); - clear_bit(BarriersNotsupp, &rdev->flags); if (mddev->raid_disks == 0) { mddev->major_version = 1; @@ -4506,7 +4441,6 @@ int md_run(mddev_t *mddev) /* may be over-ridden by personality */ mddev->resync_max_sectors = mddev->dev_sectors; - mddev->barriers_work = 1; mddev->ok_start_degraded = start_dirty_degraded; if (start_readonly && mddev->ro == 0) @@ -4685,7 +4619,6 @@ static void md_clean(mddev_t *mddev) mddev->recovery = 0; mddev->in_sync = 0; mddev->degraded = 0; - mddev->barriers_work = 0; mddev->safemode = 0; mddev->bitmap_info.offset = 0; mddev->bitmap_info.default_offset = 0; diff --git a/drivers/md/md.h b/drivers/md/md.h index a953fe2..d8e2ab2 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -87,7 +87,6 @@ struct mdk_rdev_s #define Faulty 1 /* device is known to have a fault */ #define In_sync 2 /* device is in_sync with rest of array */ #define WriteMostly 4 /* Avoid reading if at all possible */ -#define BarriersNotsupp 5 /* REQ_HARDBARRIER is not supported */ #define AllReserved 6 /* If whole device is reserved for * one array */ #define AutoDetected 7 /* added by auto-detect */ @@ -273,13 +272,6 @@ struct mddev_s int degraded; /* whether md should consider * adding a spare */ - int barriers_work; /* initialised to true, cleared as soon - * as a barrier request to slave - * fails. Only supported - */ - struct bio *biolist; /* bios that need to be retried - * because REQ_HARDBARRIER is not supported - */ atomic_t recovery_active; /* blocks scheduled, but not written */ wait_queue_head_t recovery_wait; @@ -339,16 +331,13 @@ struct mddev_s struct attribute_group *to_remove; struct plug_handle *plug; /* if used by personality */ - /* Generic barrier handling. - * If there is a pending barrier request, all other - * writes are blocked while the devices are flushed. - * The last to finish a flush schedules a worker to - * submit the barrier request (without the barrier flag), - * then submit more flush requests. + /* Generic flush handling. + * The last to finish preflush schedules a worker to submit + * the rest of the request (without the REQ_FLUSH flag). */ - struct bio *barrier; + struct bio *flush_bio; atomic_t flush_pending; - struct work_struct barrier_work; + struct work_struct flush_work; struct work_struct event_work; /* used by dm to report failure event */ }; @@ -502,7 +491,7 @@ extern void md_done_sync(mddev_t *mddev, int blocks, int ok); extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev); extern int mddev_congested(mddev_t *mddev, int bits); -extern void md_barrier_request(mddev_t *mddev, struct bio *bio); +extern void md_flush_request(mddev_t *mddev, struct bio *bio); extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev, sector_t sector, int size, struct page *page); extern void md_super_wait(mddev_t *mddev); diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c index 0307d21..6d7ddf3 100644 --- a/drivers/md/multipath.c +++ b/drivers/md/multipath.c @@ -142,8 +142,8 @@ static int multipath_make_request(mddev_t *mddev, struct bio * bio) struct multipath_bh * mp_bh; struct multipath_info *multipath; - if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) { - md_barrier_request(mddev, bio); + if (unlikely(bio->bi_rw & REQ_FLUSH)) { + md_flush_request(mddev, bio); return 0; } diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 6f7af46..a39f4c3 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -483,8 +483,8 @@ static int raid0_make_request(mddev_t *mddev, struct bio *bio) struct strip_zone *zone; mdk_rdev_t *tmp_dev; - if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) { - md_barrier_request(mddev, bio); + if (unlikely(bio->bi_rw & REQ_FLUSH)) { + md_flush_request(mddev, bio); return 0; } diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index ad83a4d..886a9d8 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -319,83 +319,74 @@ static void raid1_end_write_request(struct bio *bio, int error) if (r1_bio->bios[mirror] == bio) break; - if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) { - set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags); - set_bit(R1BIO_BarrierRetry, &r1_bio->state); - r1_bio->mddev->barriers_work = 0; - /* Don't rdev_dec_pending in this branch - keep it for the retry */ - } else { + /* + * 'one mirror IO has finished' event handler: + */ + r1_bio->bios[mirror] = NULL; + to_put = bio; + if (!uptodate) { + md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); + /* an I/O failed, we can't clear the bitmap */ + set_bit(R1BIO_Degraded, &r1_bio->state); + } else /* - * this branch is our 'one mirror IO has finished' event handler: + * Set R1BIO_Uptodate in our master bio, so that we + * will return a good error code for to the higher + * levels even if IO on some other mirrored buffer + * fails. + * + * The 'master' represents the composite IO operation + * to user-side. So if something waits for IO, then it + * will wait for the 'master' bio. */ - r1_bio->bios[mirror] = NULL; - to_put = bio; - if (!uptodate) { - md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); - /* an I/O failed, we can't clear the bitmap */ - set_bit(R1BIO_Degraded, &r1_bio->state); - } else - /* - * Set R1BIO_Uptodate in our master bio, so that - * we will return a good error code for to the higher - * levels even if IO on some other mirrored buffer fails. - * - * The 'master' represents the composite IO operation to - * user-side. So if something waits for IO, then it will - * wait for the 'master' bio. - */ - set_bit(R1BIO_Uptodate, &r1_bio->state); - - update_head_pos(mirror, r1_bio); - - if (behind) { - if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) - atomic_dec(&r1_bio->behind_remaining); - - /* In behind mode, we ACK the master bio once the I/O has safely - * reached all non-writemostly disks. Setting the Returned bit - * ensures that this gets done only once -- we don't ever want to - * return -EIO here, instead we'll wait */ - - if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && - test_bit(R1BIO_Uptodate, &r1_bio->state)) { - /* Maybe we can return now */ - if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { - struct bio *mbio = r1_bio->master_bio; - PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n", - (unsigned long long) mbio->bi_sector, - (unsigned long long) mbio->bi_sector + - (mbio->bi_size >> 9) - 1); - bio_endio(mbio, 0); - } + set_bit(R1BIO_Uptodate, &r1_bio->state); + + update_head_pos(mirror, r1_bio); + + if (behind) { + if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) + atomic_dec(&r1_bio->behind_remaining); + + /* + * In behind mode, we ACK the master bio once the I/O + * has safely reached all non-writemostly + * disks. Setting the Returned bit ensures that this + * gets done only once -- we don't ever want to return + * -EIO here, instead we'll wait + */ + if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && + test_bit(R1BIO_Uptodate, &r1_bio->state)) { + /* Maybe we can return now */ + if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { + struct bio *mbio = r1_bio->master_bio; + PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n", + (unsigned long long) mbio->bi_sector, + (unsigned long long) mbio->bi_sector + + (mbio->bi_size >> 9) - 1); + bio_endio(mbio, 0); } } - rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); } + rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); + /* - * * Let's see if all mirrored write operations have finished * already. */ if (atomic_dec_and_test(&r1_bio->remaining)) { - if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) - reschedule_retry(r1_bio); - else { - /* it really is the end of this request */ - if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { - /* free extra copy of the data pages */ - int i = bio->bi_vcnt; - while (i--) - safe_put_page(bio->bi_io_vec[i].bv_page); - } - /* clear the bitmap if all writes complete successfully */ - bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, - r1_bio->sectors, - !test_bit(R1BIO_Degraded, &r1_bio->state), - behind); - md_write_end(r1_bio->mddev); - raid_end_bio_io(r1_bio); + if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { + /* free extra copy of the data pages */ + int i = bio->bi_vcnt; + while (i--) + safe_put_page(bio->bi_io_vec[i].bv_page); } + /* clear the bitmap if all writes complete successfully */ + bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, + r1_bio->sectors, + !test_bit(R1BIO_Degraded, &r1_bio->state), + behind); + md_write_end(r1_bio->mddev); + raid_end_bio_io(r1_bio); } if (to_put) @@ -788,16 +779,13 @@ static int make_request(mddev_t *mddev, struct bio * bio) struct page **behind_pages = NULL; const int rw = bio_data_dir(bio); const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); - unsigned long do_barriers; + const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA)); mdk_rdev_t *blocked_rdev; /* * Register the new request and wait if the reconstruction * thread has put up a bar for new requests. * Continue immediately if no resync is active currently. - * We test barriers_work *after* md_write_start as md_write_start - * may cause the first superblock write, and that will check out - * if barriers work. */ md_write_start(mddev, bio); /* wait on superblock update early */ @@ -821,13 +809,6 @@ static int make_request(mddev_t *mddev, struct bio * bio) } finish_wait(&conf->wait_barrier, &w); } - if (unlikely(!mddev->barriers_work && - (bio->bi_rw & REQ_HARDBARRIER))) { - if (rw == WRITE) - md_write_end(mddev); - bio_endio(bio, -EOPNOTSUPP); - return 0; - } wait_barrier(conf); @@ -959,10 +940,6 @@ static int make_request(mddev_t *mddev, struct bio * bio) atomic_set(&r1_bio->remaining, 0); atomic_set(&r1_bio->behind_remaining, 0); - do_barriers = bio->bi_rw & REQ_HARDBARRIER; - if (do_barriers) - set_bit(R1BIO_Barrier, &r1_bio->state); - bio_list_init(&bl); for (i = 0; i < disks; i++) { struct bio *mbio; @@ -975,7 +952,7 @@ static int make_request(mddev_t *mddev, struct bio * bio) mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; mbio->bi_bdev = conf->mirrors[i].rdev->bdev; mbio->bi_end_io = raid1_end_write_request; - mbio->bi_rw = WRITE | do_barriers | do_sync; + mbio->bi_rw = WRITE | do_flush_fua | do_sync; mbio->bi_private = r1_bio; if (behind_pages) { @@ -1634,41 +1611,6 @@ static void raid1d(mddev_t *mddev) if (test_bit(R1BIO_IsSync, &r1_bio->state)) { sync_request_write(mddev, r1_bio); unplug = 1; - } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) { - /* some requests in the r1bio were REQ_HARDBARRIER - * requests which failed with -EOPNOTSUPP. Hohumm.. - * Better resubmit without the barrier. - * We know which devices to resubmit for, because - * all others have had their bios[] entry cleared. - * We already have a nr_pending reference on these rdevs. - */ - int i; - const unsigned long do_sync = (r1_bio->master_bio->bi_rw & REQ_SYNC); - clear_bit(R1BIO_BarrierRetry, &r1_bio->state); - clear_bit(R1BIO_Barrier, &r1_bio->state); - for (i=0; i < conf->raid_disks; i++) - if (r1_bio->bios[i]) - atomic_inc(&r1_bio->remaining); - for (i=0; i < conf->raid_disks; i++) - if (r1_bio->bios[i]) { - struct bio_vec *bvec; - int j; - - bio = bio_clone(r1_bio->master_bio, GFP_NOIO); - /* copy pages from the failed bio, as - * this might be a write-behind device */ - __bio_for_each_segment(bvec, bio, j, 0) - bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page; - bio_put(r1_bio->bios[i]); - bio->bi_sector = r1_bio->sector + - conf->mirrors[i].rdev->data_offset; - bio->bi_bdev = conf->mirrors[i].rdev->bdev; - bio->bi_end_io = raid1_end_write_request; - bio->bi_rw = WRITE | do_sync; - bio->bi_private = r1_bio; - r1_bio->bios[i] = bio; - generic_make_request(bio); - } } else { int disk; diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h index 5f2d443..adf8cfd 100644 --- a/drivers/md/raid1.h +++ b/drivers/md/raid1.h @@ -117,8 +117,6 @@ struct r1bio_s { #define R1BIO_IsSync 1 #define R1BIO_Degraded 2 #define R1BIO_BehindIO 3 -#define R1BIO_Barrier 4 -#define R1BIO_BarrierRetry 5 /* For write-behind requests, we call bi_end_io when * the last non-write-behind device completes, providing * any write was successful. Otherwise we call when diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 8471838..f0d082f 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -800,12 +800,13 @@ static int make_request(mddev_t *mddev, struct bio * bio) int chunk_sects = conf->chunk_mask + 1; const int rw = bio_data_dir(bio); const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); + const unsigned long do_fua = (bio->bi_rw & REQ_FUA); struct bio_list bl; unsigned long flags; mdk_rdev_t *blocked_rdev; - if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) { - md_barrier_request(mddev, bio); + if (unlikely(bio->bi_rw & REQ_FLUSH)) { + md_flush_request(mddev, bio); return 0; } @@ -965,7 +966,7 @@ static int make_request(mddev_t *mddev, struct bio * bio) conf->mirrors[d].rdev->data_offset; mbio->bi_bdev = conf->mirrors[d].rdev->bdev; mbio->bi_end_io = raid10_end_write_request; - mbio->bi_rw = WRITE | do_sync; + mbio->bi_rw = WRITE | do_sync | do_fua; mbio->bi_private = r10_bio; atomic_inc(&r10_bio->remaining); diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 69b0a16..31140d1 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -506,9 +506,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) int rw; struct bio *bi; mdk_rdev_t *rdev; - if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) - rw = WRITE; - else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) + if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { + if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags)) + rw = WRITE_FUA; + else + rw = WRITE; + } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags)) rw = READ; else continue; @@ -1031,6 +1034,8 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { + if (wbi->bi_rw & REQ_FUA) + set_bit(R5_WantFUA, &dev->flags); tx = async_copy_data(1, wbi, dev->page, dev->sector, tx); wbi = r5_next_bio(wbi, dev->sector); @@ -1048,15 +1053,22 @@ static void ops_complete_reconstruct(void *stripe_head_ref) int pd_idx = sh->pd_idx; int qd_idx = sh->qd_idx; int i; + bool fua = false; pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); + for (i = disks; i--; ) + fua |= test_bit(R5_WantFUA, &sh->dev[i].flags); + for (i = disks; i--; ) { struct r5dev *dev = &sh->dev[i]; - if (dev->written || i == pd_idx || i == qd_idx) + if (dev->written || i == pd_idx || i == qd_idx) { set_bit(R5_UPTODATE, &dev->flags); + if (fua) + set_bit(R5_WantFUA, &dev->flags); + } } if (sh->reconstruct_state == reconstruct_state_drain_run) @@ -3281,7 +3293,7 @@ static void handle_stripe5(struct stripe_head *sh) if (dec_preread_active) { /* We delay this until after ops_run_io so that if make_request - * is waiting on a barrier, it won't continue until the writes + * is waiting on a flush, it won't continue until the writes * have actually been submitted. */ atomic_dec(&conf->preread_active_stripes); @@ -3583,7 +3595,7 @@ static void handle_stripe6(struct stripe_head *sh) if (dec_preread_active) { /* We delay this until after ops_run_io so that if make_request - * is waiting on a barrier, it won't continue until the writes + * is waiting on a flush, it won't continue until the writes * have actually been submitted. */ atomic_dec(&conf->preread_active_stripes); @@ -3978,14 +3990,8 @@ static int make_request(mddev_t *mddev, struct bio * bi) const int rw = bio_data_dir(bi); int remaining; - if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) { - /* Drain all pending writes. We only really need - * to ensure they have been submitted, but this is - * easier. - */ - mddev->pers->quiesce(mddev, 1); - mddev->pers->quiesce(mddev, 0); - md_barrier_request(mddev, bi); + if (unlikely(bi->bi_rw & REQ_FLUSH)) { + md_flush_request(mddev, bi); return 0; } @@ -4103,7 +4109,7 @@ static int make_request(mddev_t *mddev, struct bio * bi) finish_wait(&conf->wait_for_overlap, &w); set_bit(STRIPE_HANDLE, &sh->state); clear_bit(STRIPE_DELAYED, &sh->state); - if (mddev->barrier && + if ((bi->bi_rw & REQ_SYNC) && !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) atomic_inc(&conf->preread_active_stripes); release_stripe(sh); @@ -4126,13 +4132,6 @@ static int make_request(mddev_t *mddev, struct bio * bi) bio_endio(bi, 0); } - if (mddev->barrier) { - /* We need to wait for the stripes to all be handled. - * So: wait for preread_active_stripes to drop to 0. - */ - wait_event(mddev->thread->wqueue, - atomic_read(&conf->preread_active_stripes) == 0); - } return 0; } diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 36eaed5..2ace058 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -275,6 +275,7 @@ struct r6_state { * filling */ #define R5_Wantdrain 13 /* dev->towrite needs to be drained */ +#define R5_WantFUA 14 /* Write should be FUA */ /* * Write method */ -- cgit v1.1 From d87f4c14f27dc82d215108d8392a7d26687148a1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Sep 2010 11:56:19 +0200 Subject: dm: implement REQ_FLUSH/FUA support for bio-based dm This patch converts bio-based dm to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. * -EOPNOTSUPP handling logic dropped. * Preflush is handled as before but postflush is dropped and replaced with passing down REQ_FUA to member request_queues. This replaces one array wide cache flush w/ member specific FUA writes. * __split_and_process_bio() now calls __clone_and_map_flush() directly for flushes and guarantees all FLUSH bio's going to targets are zero ` length. * It's now guaranteed that all FLUSH bio's which are passed onto dm targets are zero length. bio_empty_barrier() tests are replaced with REQ_FLUSH tests. * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes. * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely enough to be marked with unlikely(). * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA capability. * Request based dm isn't converted yet. dm_init_request_based_queue() resets flush support to 0 for now. To avoid disturbing request based dm code, dm->flush_error is added for bio based dm while requested based dm continues to use dm->barrier_error. Lightly tested linear, stripe, raid1, snap and crypt targets. Please proceed with caution as I'm not familiar with the code base. Signed-off-by: Tejun Heo Cc: dm-devel@redhat.com Cc: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/md/dm-crypt.c | 2 +- drivers/md/dm-io.c | 20 ++----- drivers/md/dm-log.c | 2 +- drivers/md/dm-raid1.c | 8 +-- drivers/md/dm-region-hash.c | 16 +++--- drivers/md/dm-snap-persistent.c | 2 +- drivers/md/dm-snap.c | 6 +- drivers/md/dm-stripe.c | 2 +- drivers/md/dm.c | 119 +++++++++++++++++++--------------------- 9 files changed, 80 insertions(+), 97 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 368e8e9..d5b0e4c 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio, struct dm_crypt_io *io; struct crypt_config *cc; - if (unlikely(bio_empty_barrier(bio))) { + if (bio->bi_rw & REQ_FLUSH) { cc = ti->private; bio->bi_bdev = cc->dev->bdev; return DM_MAPIO_REMAPPED; diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index 0590c75..136d4f7 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -31,7 +31,6 @@ struct dm_io_client { */ struct io { unsigned long error_bits; - unsigned long eopnotsupp_bits; atomic_t count; struct task_struct *sleeper; struct dm_io_client *client; @@ -130,11 +129,8 @@ static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, *---------------------------------------------------------------*/ static void dec_count(struct io *io, unsigned int region, int error) { - if (error) { + if (error) set_bit(region, &io->error_bits); - if (error == -EOPNOTSUPP) - set_bit(region, &io->eopnotsupp_bits); - } if (atomic_dec_and_test(&io->count)) { if (io->sleeper) @@ -310,8 +306,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, sector_t remaining = where->count; /* - * where->count may be zero if rw holds a write barrier and we - * need to send a zero-sized barrier. + * where->count may be zero if rw holds a flush and we need to + * send a zero-sized flush. */ do { /* @@ -364,7 +360,7 @@ static void dispatch_io(int rw, unsigned int num_regions, */ for (i = 0; i < num_regions; i++) { *dp = old_pages; - if (where[i].count || (rw & REQ_HARDBARRIER)) + if (where[i].count || (rw & REQ_FLUSH)) do_region(rw, i, where + i, dp, io); } @@ -393,9 +389,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, return -EIO; } -retry: io->error_bits = 0; - io->eopnotsupp_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->sleeper = current; io->client = client; @@ -412,11 +406,6 @@ retry: } set_current_state(TASK_RUNNING); - if (io->eopnotsupp_bits && (rw & REQ_HARDBARRIER)) { - rw &= ~REQ_HARDBARRIER; - goto retry; - } - if (error_bits) *error_bits = io->error_bits; @@ -437,7 +426,6 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions, io = mempool_alloc(client->pool, GFP_NOIO); io->error_bits = 0; - io->eopnotsupp_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->sleeper = NULL; io->client = client; diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c index 5a08be0..33420e6 100644 --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -300,7 +300,7 @@ static int flush_header(struct log_c *lc) .count = 0, }; - lc->io_req.bi_rw = WRITE_BARRIER; + lc->io_req.bi_rw = WRITE_FLUSH; return dm_io(&lc->io_req, 1, &null_location, NULL); } diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index 7c081bc..19a59b0 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -259,7 +259,7 @@ static int mirror_flush(struct dm_target *ti) struct dm_io_region io[ms->nr_mirrors]; struct mirror *m; struct dm_io_request io_req = { - .bi_rw = WRITE_BARRIER, + .bi_rw = WRITE_FLUSH, .mem.type = DM_IO_KMEM, .mem.ptr.bvec = NULL, .client = ms->io_client, @@ -629,7 +629,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio) struct dm_io_region io[ms->nr_mirrors], *dest = io; struct mirror *m; struct dm_io_request io_req = { - .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER), + .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA), .mem.type = DM_IO_BVEC, .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx, .notify.fn = write_callback, @@ -670,7 +670,7 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes) bio_list_init(&requeue); while ((bio = bio_list_pop(writes))) { - if (unlikely(bio_empty_barrier(bio))) { + if (bio->bi_rw & REQ_FLUSH) { bio_list_add(&sync, bio); continue; } @@ -1203,7 +1203,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, * We need to dec pending if this was a write. */ if (rw == WRITE) { - if (likely(!bio_empty_barrier(bio))) + if (!(bio->bi_rw & REQ_FLUSH)) dm_rh_dec(ms->rh, map_context->ll); return error; } diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c index bd5c58b..dad011a 100644 --- a/drivers/md/dm-region-hash.c +++ b/drivers/md/dm-region-hash.c @@ -81,9 +81,9 @@ struct dm_region_hash { struct list_head failed_recovered_regions; /* - * If there was a barrier failure no regions can be marked clean. + * If there was a flush failure no regions can be marked clean. */ - int barrier_failure; + int flush_failure; void *context; sector_t target_begin; @@ -217,7 +217,7 @@ struct dm_region_hash *dm_region_hash_create( INIT_LIST_HEAD(&rh->quiesced_regions); INIT_LIST_HEAD(&rh->recovered_regions); INIT_LIST_HEAD(&rh->failed_recovered_regions); - rh->barrier_failure = 0; + rh->flush_failure = 0; rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS, sizeof(struct dm_region)); @@ -399,8 +399,8 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio) region_t region = dm_rh_bio_to_region(rh, bio); int recovering = 0; - if (bio_empty_barrier(bio)) { - rh->barrier_failure = 1; + if (bio->bi_rw & REQ_FLUSH) { + rh->flush_failure = 1; return; } @@ -524,7 +524,7 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios) struct bio *bio; for (bio = bios->head; bio; bio = bio->bi_next) { - if (bio_empty_barrier(bio)) + if (bio->bi_rw & REQ_FLUSH) continue; rh_inc(rh, dm_rh_bio_to_region(rh, bio)); } @@ -555,9 +555,9 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region) */ /* do nothing for DM_RH_NOSYNC */ - if (unlikely(rh->barrier_failure)) { + if (unlikely(rh->flush_failure)) { /* - * If a write barrier failed some time ago, we + * If a write flush failed some time ago, we * don't know whether or not this write made it * to the disk, so we must resync the device. */ diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index cc2bdb8..0b61792 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -687,7 +687,7 @@ static void persistent_commit_exception(struct dm_exception_store *store, /* * Commit exceptions to disk. */ - if (ps->valid && area_io(ps, WRITE_BARRIER)) + if (ps->valid && area_io(ps, WRITE_FLUSH_FUA)) ps->valid = 0; /* diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 5974d30..eed2101 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -1587,7 +1587,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio, chunk_t chunk; struct dm_snap_pending_exception *pe = NULL; - if (unlikely(bio_empty_barrier(bio))) { + if (bio->bi_rw & REQ_FLUSH) { bio->bi_bdev = s->cow->bdev; return DM_MAPIO_REMAPPED; } @@ -1691,7 +1691,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio, int r = DM_MAPIO_REMAPPED; chunk_t chunk; - if (unlikely(bio_empty_barrier(bio))) { + if (bio->bi_rw & REQ_FLUSH) { if (!map_context->target_request_nr) bio->bi_bdev = s->origin->bdev; else @@ -2135,7 +2135,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio, struct dm_dev *dev = ti->private; bio->bi_bdev = dev->bdev; - if (unlikely(bio_empty_barrier(bio))) + if (bio->bi_rw & REQ_FLUSH) return DM_MAPIO_REMAPPED; /* Only tell snapshots if this is a write */ diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index c297f6d..f0371b4 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -271,7 +271,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio, uint32_t stripe; unsigned target_request_nr; - if (unlikely(bio_empty_barrier(bio))) { + if (bio->bi_rw & REQ_FLUSH) { target_request_nr = map_context->target_request_nr; BUG_ON(target_request_nr >= sc->stripes); bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b1d92be..32e6622 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -144,15 +144,16 @@ struct mapped_device { spinlock_t deferred_lock; /* - * An error from the barrier request currently being processed. + * An error from the flush request currently being processed. */ - int barrier_error; + int flush_error; /* * Protect barrier_error from concurrent endio processing * in request-based dm. */ spinlock_t barrier_error_lock; + int barrier_error; /* * Processing queue (flush/barriers) @@ -200,8 +201,8 @@ struct mapped_device { /* sysfs handle */ struct kobject kobj; - /* zero-length barrier that will be cloned and submitted to targets */ - struct bio barrier_bio; + /* zero-length flush that will be cloned and submitted to targets */ + struct bio flush_bio; }; /* @@ -512,7 +513,7 @@ static void end_io_acct(struct dm_io *io) /* * After this is decremented the bio must not be touched if it is - * a barrier. + * a flush. */ dm_disk(md)->part0.in_flight[rw] = pending = atomic_dec_return(&md->pending[rw]); @@ -626,7 +627,7 @@ static void dec_pending(struct dm_io *io, int error) */ spin_lock_irqsave(&md->deferred_lock, flags); if (__noflush_suspending(md)) { - if (!(io->bio->bi_rw & REQ_HARDBARRIER)) + if (!(io->bio->bi_rw & REQ_FLUSH)) bio_list_add_head(&md->deferred, io->bio); } else @@ -638,20 +639,14 @@ static void dec_pending(struct dm_io *io, int error) io_error = io->error; bio = io->bio; - if (bio->bi_rw & REQ_HARDBARRIER) { + if (bio->bi_rw & REQ_FLUSH) { /* - * There can be just one barrier request so we use + * There can be just one flush request so we use * a per-device variable for error reporting. * Note that you can't touch the bio after end_io_acct - * - * We ignore -EOPNOTSUPP for empty flush reported by - * underlying devices. We assume that if the device - * doesn't support empty barriers, it doesn't need - * cache flushing commands. */ - if (!md->barrier_error && - !(bio_empty_barrier(bio) && io_error == -EOPNOTSUPP)) - md->barrier_error = io_error; + if (!md->flush_error) + md->flush_error = io_error; end_io_acct(io); free_io(md, io); } else { @@ -1119,7 +1114,7 @@ static void dm_bio_destructor(struct bio *bio) } /* - * Creates a little bio that is just does part of a bvec. + * Creates a little bio that just does part of a bvec. */ static struct bio *split_bvec(struct bio *bio, sector_t sector, unsigned short idx, unsigned int offset, @@ -1134,7 +1129,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector, clone->bi_sector = sector; clone->bi_bdev = bio->bi_bdev; - clone->bi_rw = bio->bi_rw & ~REQ_HARDBARRIER; + clone->bi_rw = bio->bi_rw; clone->bi_vcnt = 1; clone->bi_size = to_bytes(len); clone->bi_io_vec->bv_offset = offset; @@ -1161,7 +1156,6 @@ static struct bio *clone_bio(struct bio *bio, sector_t sector, clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs); __bio_clone(clone, bio); - clone->bi_rw &= ~REQ_HARDBARRIER; clone->bi_destructor = dm_bio_destructor; clone->bi_sector = sector; clone->bi_idx = idx; @@ -1225,7 +1219,7 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti, __issue_target_request(ci, ti, request_nr, len); } -static int __clone_and_map_empty_barrier(struct clone_info *ci) +static int __clone_and_map_flush(struct clone_info *ci) { unsigned target_nr = 0; struct dm_target *ti; @@ -1289,9 +1283,6 @@ static int __clone_and_map(struct clone_info *ci) sector_t len = 0, max; struct dm_target_io *tio; - if (unlikely(bio_empty_barrier(bio))) - return __clone_and_map_empty_barrier(ci); - if (unlikely(bio->bi_rw & REQ_DISCARD)) return __clone_and_map_discard(ci); @@ -1383,11 +1374,11 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) ci.map = dm_get_live_table(md); if (unlikely(!ci.map)) { - if (!(bio->bi_rw & REQ_HARDBARRIER)) + if (!(bio->bi_rw & REQ_FLUSH)) bio_io_error(bio); else - if (!md->barrier_error) - md->barrier_error = -EIO; + if (!md->flush_error) + md->flush_error = -EIO; return; } @@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) ci.io->md = md; spin_lock_init(&ci.io->endio_lock); ci.sector = bio->bi_sector; - ci.sector_count = bio_sectors(bio); - if (unlikely(bio_empty_barrier(bio))) + if (!(bio->bi_rw & REQ_FLUSH)) + ci.sector_count = bio_sectors(bio); + else { + /* all FLUSH bio's reaching here should be empty */ + WARN_ON_ONCE(bio_has_data(bio)); ci.sector_count = 1; + } ci.idx = bio->bi_idx; start_io_acct(ci.io); - while (ci.sector_count && !error) - error = __clone_and_map(&ci); + while (ci.sector_count && !error) { + if (!(bio->bi_rw & REQ_FLUSH)) + error = __clone_and_map(&ci); + else + error = __clone_and_map_flush(&ci); + } /* drop the extra reference count */ dec_pending(ci.io, error); @@ -1492,11 +1491,11 @@ static int _dm_request(struct request_queue *q, struct bio *bio) part_stat_unlock(); /* - * If we're suspended or the thread is processing barriers + * If we're suspended or the thread is processing flushes * we have to queue this io for later. */ if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) || - unlikely(bio->bi_rw & REQ_HARDBARRIER)) { + (bio->bi_rw & REQ_FLUSH)) { up_read(&md->io_lock); if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) && @@ -1940,6 +1939,7 @@ static void dm_init_md_queue(struct mapped_device *md) blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); md->queue->unplug_fn = dm_unplug_all; blk_queue_merge_bvec(md->queue, dm_merge_bvec); + blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA); } /* @@ -2245,7 +2245,8 @@ static int dm_init_request_based_queue(struct mapped_device *md) blk_queue_softirq_done(md->queue, dm_softirq_done); blk_queue_prep_rq(md->queue, dm_prep_fn); blk_queue_lld_busy(md->queue, dm_lld_busy); - blk_queue_flush(md->queue, REQ_FLUSH); + /* no flush support for request based dm yet */ + blk_queue_flush(md->queue, 0); elv_register_queue(md->queue); @@ -2406,41 +2407,35 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible) return r; } -static void dm_flush(struct mapped_device *md) +static void process_flush(struct mapped_device *md, struct bio *bio) { - dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); - - bio_init(&md->barrier_bio); - md->barrier_bio.bi_bdev = md->bdev; - md->barrier_bio.bi_rw = WRITE_BARRIER; - __split_and_process_bio(md, &md->barrier_bio); + md->flush_error = 0; + /* handle REQ_FLUSH */ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); -} -static void process_barrier(struct mapped_device *md, struct bio *bio) -{ - md->barrier_error = 0; + bio_init(&md->flush_bio); + md->flush_bio.bi_bdev = md->bdev; + md->flush_bio.bi_rw = WRITE_FLUSH; + __split_and_process_bio(md, &md->flush_bio); - dm_flush(md); + dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); - if (!bio_empty_barrier(bio)) { - __split_and_process_bio(md, bio); - /* - * If the request isn't supported, don't waste time with - * the second flush. - */ - if (md->barrier_error != -EOPNOTSUPP) - dm_flush(md); + /* if it's an empty flush or the preflush failed, we're done */ + if (!bio_has_data(bio) || md->flush_error) { + if (md->flush_error != DM_ENDIO_REQUEUE) + bio_endio(bio, md->flush_error); + else { + spin_lock_irq(&md->deferred_lock); + bio_list_add_head(&md->deferred, bio); + spin_unlock_irq(&md->deferred_lock); + } + return; } - if (md->barrier_error != DM_ENDIO_REQUEUE) - bio_endio(bio, md->barrier_error); - else { - spin_lock_irq(&md->deferred_lock); - bio_list_add_head(&md->deferred, bio); - spin_unlock_irq(&md->deferred_lock); - } + /* issue data + REQ_FUA */ + bio->bi_rw &= ~REQ_FLUSH; + __split_and_process_bio(md, bio); } /* @@ -2469,8 +2464,8 @@ static void dm_wq_work(struct work_struct *work) if (dm_request_based(md)) generic_make_request(c); else { - if (c->bi_rw & REQ_HARDBARRIER) - process_barrier(md, c); + if (c->bi_rw & REQ_FLUSH) + process_flush(md, c); else __split_and_process_bio(md, c); } -- cgit v1.1 From 29e4013de7ad950280e4b220894986866697d419 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 8 Sep 2010 18:07:00 +0200 Subject: dm: implement REQ_FLUSH/FUA support for request-based dm This patch converts request-based dm to support the new REQ_FLUSH/FUA. The original request-based flush implementation depended on request_queue blocking other requests while a barrier sequence is in progress, which is no longer true for the new REQ_FLUSH/FUA. In general, request-based dm doesn't have infrastructure for cloning one source request to multiple targets, but the original flush implementation had a special mostly independent path which can issue flushes to multiple targets and sequence them. However, the capability isn't currently in use and adds a lot of complexity. Moreoever, it's unlikely to be useful in its current form as it doesn't make sense to be able to send out flushes to multiple targets when write requests can't be. This patch rips out special flush code path and deals handles REQ_FLUSH/FUA requests the same way as other requests. The only special treatment is that REQ_FLUSH requests use the block address 0 when finding target, which is enough for now. * added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as suggested by Mike Snitzer Signed-off-by: Tejun Heo Acked-by: Mike Snitzer Tested-by: Kiyoshi Ueda Signed-off-by: Jens Axboe --- drivers/md/dm.c | 206 ++++++-------------------------------------------------- 1 file changed, 22 insertions(+), 184 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 32e6622..65114e4 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -149,20 +149,9 @@ struct mapped_device { int flush_error; /* - * Protect barrier_error from concurrent endio processing - * in request-based dm. - */ - spinlock_t barrier_error_lock; - int barrier_error; - - /* - * Processing queue (flush/barriers) + * Processing queue (flush) */ struct workqueue_struct *wq; - struct work_struct barrier_work; - - /* A pointer to the currently processing pre/post flush request */ - struct request *flush_request; /* * The current mapping. @@ -750,23 +739,6 @@ static void end_clone_bio(struct bio *clone, int error) blk_update_request(tio->orig, 0, nr_bytes); } -static void store_barrier_error(struct mapped_device *md, int error) -{ - unsigned long flags; - - spin_lock_irqsave(&md->barrier_error_lock, flags); - /* - * Basically, the first error is taken, but: - * -EOPNOTSUPP supersedes any I/O error. - * Requeue request supersedes any I/O error but -EOPNOTSUPP. - */ - if (!md->barrier_error || error == -EOPNOTSUPP || - (md->barrier_error != -EOPNOTSUPP && - error == DM_ENDIO_REQUEUE)) - md->barrier_error = error; - spin_unlock_irqrestore(&md->barrier_error_lock, flags); -} - /* * Don't touch any member of the md after calling this function because * the md may be freed in dm_put() at the end of this function. @@ -804,13 +776,11 @@ static void free_rq_clone(struct request *clone) static void dm_end_request(struct request *clone, int error) { int rw = rq_data_dir(clone); - int run_queue = 1; - bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER; struct dm_rq_target_io *tio = clone->end_io_data; struct mapped_device *md = tio->md; struct request *rq = tio->orig; - if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) { + if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { rq->errors = clone->errors; rq->resid_len = clone->resid_len; @@ -824,15 +794,8 @@ static void dm_end_request(struct request *clone, int error) } free_rq_clone(clone); - - if (unlikely(is_barrier)) { - if (unlikely(error)) - store_barrier_error(md, error); - run_queue = 0; - } else - blk_end_request_all(rq, error); - - rq_completed(md, rw, run_queue); + blk_end_request_all(rq, error); + rq_completed(md, rw, true); } static void dm_unprep_request(struct request *rq) @@ -857,16 +820,6 @@ void dm_requeue_unmapped_request(struct request *clone) struct request_queue *q = rq->q; unsigned long flags; - if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) { - /* - * Barrier clones share an original request. - * Leave it to dm_end_request(), which handles this special - * case. - */ - dm_end_request(clone, DM_ENDIO_REQUEUE); - return; - } - dm_unprep_request(rq); spin_lock_irqsave(q->queue_lock, flags); @@ -956,19 +909,6 @@ static void dm_complete_request(struct request *clone, int error) struct dm_rq_target_io *tio = clone->end_io_data; struct request *rq = tio->orig; - if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) { - /* - * Barrier clones share an original request. So can't use - * softirq_done with the original. - * Pass the clone to dm_done() directly in this special case. - * It is safe (even if clone->q->queue_lock is held here) - * because there is no I/O dispatching during the completion - * of barrier clone. - */ - dm_done(clone, error, true); - return; - } - tio->error = error; rq->completion_data = clone; blk_complete_request(rq); @@ -985,17 +925,6 @@ void dm_kill_unmapped_request(struct request *clone, int error) struct dm_rq_target_io *tio = clone->end_io_data; struct request *rq = tio->orig; - if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) { - /* - * Barrier clones share an original request. - * Leave it to dm_end_request(), which handles this special - * case. - */ - BUG_ON(error > 0); - dm_end_request(clone, error); - return; - } - rq->cmd_flags |= REQ_FAILED; dm_complete_request(clone, error); } @@ -1536,14 +1465,6 @@ static int dm_request(struct request_queue *q, struct bio *bio) return _dm_request(q, bio); } -static bool dm_rq_is_flush_request(struct request *rq) -{ - if (rq->cmd_flags & REQ_FLUSH) - return true; - else - return false; -} - void dm_dispatch_request(struct request *rq) { int r; @@ -1591,22 +1512,15 @@ static int setup_clone(struct request *clone, struct request *rq, { int r; - if (dm_rq_is_flush_request(rq)) { - blk_rq_init(NULL, clone); - clone->cmd_type = REQ_TYPE_FS; - clone->cmd_flags |= (REQ_HARDBARRIER | WRITE); - } else { - r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC, - dm_rq_bio_constructor, tio); - if (r) - return r; - - clone->cmd = rq->cmd; - clone->cmd_len = rq->cmd_len; - clone->sense = rq->sense; - clone->buffer = rq->buffer; - } + r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC, + dm_rq_bio_constructor, tio); + if (r) + return r; + clone->cmd = rq->cmd; + clone->cmd_len = rq->cmd_len; + clone->sense = rq->sense; + clone->buffer = rq->buffer; clone->end_io = end_clone_request; clone->end_io_data = tio; @@ -1647,9 +1561,6 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq) struct mapped_device *md = q->queuedata; struct request *clone; - if (unlikely(dm_rq_is_flush_request(rq))) - return BLKPREP_OK; - if (unlikely(rq->special)) { DMWARN("Already has something in rq->special."); return BLKPREP_KILL; @@ -1726,6 +1637,7 @@ static void dm_request_fn(struct request_queue *q) struct dm_table *map = dm_get_live_table(md); struct dm_target *ti; struct request *rq, *clone; + sector_t pos; /* * For suspend, check blk_queue_stopped() and increment @@ -1738,15 +1650,14 @@ static void dm_request_fn(struct request_queue *q) if (!rq) goto plug_and_out; - if (unlikely(dm_rq_is_flush_request(rq))) { - BUG_ON(md->flush_request); - md->flush_request = rq; - blk_start_request(rq); - queue_work(md->wq, &md->barrier_work); - goto out; - } + /* always use block 0 to find the target for flushes for now */ + pos = 0; + if (!(rq->cmd_flags & REQ_FLUSH)) + pos = blk_rq_pos(rq); + + ti = dm_table_find_target(map, pos); + BUG_ON(!dm_target_is_valid(ti)); - ti = dm_table_find_target(map, blk_rq_pos(rq)); if (ti->type->busy && ti->type->busy(ti)) goto plug_and_out; @@ -1917,7 +1828,6 @@ out: static const struct block_device_operations dm_blk_dops; static void dm_wq_work(struct work_struct *work); -static void dm_rq_barrier_work(struct work_struct *work); static void dm_init_md_queue(struct mapped_device *md) { @@ -1972,7 +1882,6 @@ static struct mapped_device *alloc_dev(int minor) mutex_init(&md->suspend_lock); mutex_init(&md->type_lock); spin_lock_init(&md->deferred_lock); - spin_lock_init(&md->barrier_error_lock); rwlock_init(&md->map_lock); atomic_set(&md->holders, 1); atomic_set(&md->open_count, 0); @@ -1995,7 +1904,6 @@ static struct mapped_device *alloc_dev(int minor) atomic_set(&md->pending[1], 0); init_waitqueue_head(&md->wait); INIT_WORK(&md->work, dm_wq_work); - INIT_WORK(&md->barrier_work, dm_rq_barrier_work); init_waitqueue_head(&md->eventq); md->disk->major = _major; @@ -2245,8 +2153,6 @@ static int dm_init_request_based_queue(struct mapped_device *md) blk_queue_softirq_done(md->queue, dm_softirq_done); blk_queue_prep_rq(md->queue, dm_prep_fn); blk_queue_lld_busy(md->queue, dm_lld_busy); - /* no flush support for request based dm yet */ - blk_queue_flush(md->queue, 0); elv_register_queue(md->queue); @@ -2483,73 +2389,6 @@ static void dm_queue_flush(struct mapped_device *md) queue_work(md->wq, &md->work); } -static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr) -{ - struct dm_rq_target_io *tio = clone->end_io_data; - - tio->info.target_request_nr = request_nr; -} - -/* Issue barrier requests to targets and wait for their completion. */ -static int dm_rq_barrier(struct mapped_device *md) -{ - int i, j; - struct dm_table *map = dm_get_live_table(md); - unsigned num_targets = dm_table_get_num_targets(map); - struct dm_target *ti; - struct request *clone; - - md->barrier_error = 0; - - for (i = 0; i < num_targets; i++) { - ti = dm_table_get_target(map, i); - for (j = 0; j < ti->num_flush_requests; j++) { - clone = clone_rq(md->flush_request, md, GFP_NOIO); - dm_rq_set_target_request_nr(clone, j); - atomic_inc(&md->pending[rq_data_dir(clone)]); - map_request(ti, clone, md); - } - } - - dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); - dm_table_put(map); - - return md->barrier_error; -} - -static void dm_rq_barrier_work(struct work_struct *work) -{ - int error; - struct mapped_device *md = container_of(work, struct mapped_device, - barrier_work); - struct request_queue *q = md->queue; - struct request *rq; - unsigned long flags; - - /* - * Hold the md reference here and leave it at the last part so that - * the md can't be deleted by device opener when the barrier request - * completes. - */ - dm_get(md); - - error = dm_rq_barrier(md); - - rq = md->flush_request; - md->flush_request = NULL; - - if (error == DM_ENDIO_REQUEUE) { - spin_lock_irqsave(q->queue_lock, flags); - blk_requeue_request(q, rq); - spin_unlock_irqrestore(q->queue_lock, flags); - } else - blk_end_request_all(rq, error); - - blk_run_queue(q); - - dm_put(md); -} - /* * Swap in a new table, returning the old one for the caller to destroy. */ @@ -2686,9 +2525,8 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) up_write(&md->io_lock); /* - * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which - * can be kicked until md->queue is stopped. So stop md->queue before - * flushing md->wq. + * Stop md->queue before flushing md->wq in case request-based + * dm defers requests to md->wq from md->queue. */ if (dm_request_based(md)) stop_queue(md->queue); -- cgit v1.1 From 6a8736d10cb413be95ea443ba40f25c93f4ef9b2 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 8 Sep 2010 18:07:00 +0200 Subject: dm: relax ordering of bio-based flush implementation Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering against other bio's. This patch relaxes ordering around flushes. * A flush bio is no longer deferred to workqueue directly. It's processed like other bio's but __split_and_process_bio() uses md->flush_bio as the clone source. md->flush_bio is initialized to empty flush during md initialization and shared for all flushes. * As a flush bio now travels through the same execution path as other bio's, there's no need for dedicated error handling path either. It can use the same error handling path in dec_pending(). Dedicated error handling removed along with md->flush_error. * When dec_pending() detects that a flush has completed, it checks whether the original bio has data. If so, the bio is queued to the deferred list w/ REQ_FLUSH cleared; otherwise, it's completed. * As flush sequencing is handled in the usual issue/completion path, dm_wq_work() no longer needs to handle flushes differently. Now its only responsibility is re-issuing deferred bio's the same way as _dm_request() would. REQ_FLUSH handling logic including process_flush() is dropped. * There's no reason for queue_io() and dm_wq_work() write lock dm->io_lock. queue_io() now only uses md->deferred_lock and dm_wq_work() read locks dm->io_lock. * bio's no longer need to be queued on the deferred list while a flush is in progress making DMF_QUEUE_IO_TO_THREAD unncessary. Drop it. This avoids stalling the device during flushes and simplifies the implementation. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- drivers/md/dm.c | 157 ++++++++++++++++---------------------------------------- 1 file changed, 45 insertions(+), 112 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 65114e4..2011704 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -110,7 +110,6 @@ EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo); #define DMF_FREEING 3 #define DMF_DELETING 4 #define DMF_NOFLUSH_SUSPENDING 5 -#define DMF_QUEUE_IO_TO_THREAD 6 /* * Work processed by per-device workqueue. @@ -144,11 +143,6 @@ struct mapped_device { spinlock_t deferred_lock; /* - * An error from the flush request currently being processed. - */ - int flush_error; - - /* * Processing queue (flush) */ struct workqueue_struct *wq; @@ -518,16 +512,10 @@ static void end_io_acct(struct dm_io *io) */ static void queue_io(struct mapped_device *md, struct bio *bio) { - down_write(&md->io_lock); - spin_lock_irq(&md->deferred_lock); bio_list_add(&md->deferred, bio); spin_unlock_irq(&md->deferred_lock); - - if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) - queue_work(md->wq, &md->work); - - up_write(&md->io_lock); + queue_work(md->wq, &md->work); } /* @@ -615,11 +603,9 @@ static void dec_pending(struct dm_io *io, int error) * Target requested pushing back the I/O. */ spin_lock_irqsave(&md->deferred_lock, flags); - if (__noflush_suspending(md)) { - if (!(io->bio->bi_rw & REQ_FLUSH)) - bio_list_add_head(&md->deferred, - io->bio); - } else + if (__noflush_suspending(md)) + bio_list_add_head(&md->deferred, io->bio); + else /* noflush suspend was interrupted. */ io->error = -EIO; spin_unlock_irqrestore(&md->deferred_lock, flags); @@ -627,26 +613,22 @@ static void dec_pending(struct dm_io *io, int error) io_error = io->error; bio = io->bio; + end_io_acct(io); + free_io(md, io); + + if (io_error == DM_ENDIO_REQUEUE) + return; - if (bio->bi_rw & REQ_FLUSH) { + if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) { + trace_block_bio_complete(md->queue, bio); + bio_endio(bio, io_error); + } else { /* - * There can be just one flush request so we use - * a per-device variable for error reporting. - * Note that you can't touch the bio after end_io_acct + * Preflush done for flush with data, reissue + * without REQ_FLUSH. */ - if (!md->flush_error) - md->flush_error = io_error; - end_io_acct(io); - free_io(md, io); - } else { - end_io_acct(io); - free_io(md, io); - - if (io_error != DM_ENDIO_REQUEUE) { - trace_block_bio_complete(md->queue, bio); - - bio_endio(bio, io_error); - } + bio->bi_rw &= ~REQ_FLUSH; + queue_io(md, bio); } } } @@ -1298,21 +1280,17 @@ static int __clone_and_map(struct clone_info *ci) */ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) { + bool is_flush = bio->bi_rw & REQ_FLUSH; struct clone_info ci; int error = 0; ci.map = dm_get_live_table(md); if (unlikely(!ci.map)) { - if (!(bio->bi_rw & REQ_FLUSH)) - bio_io_error(bio); - else - if (!md->flush_error) - md->flush_error = -EIO; + bio_io_error(bio); return; } ci.md = md; - ci.bio = bio; ci.io = alloc_io(md); ci.io->error = 0; atomic_set(&ci.io->io_count, 1); @@ -1320,18 +1298,19 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) ci.io->md = md; spin_lock_init(&ci.io->endio_lock); ci.sector = bio->bi_sector; - if (!(bio->bi_rw & REQ_FLUSH)) + ci.idx = bio->bi_idx; + + if (!is_flush) { + ci.bio = bio; ci.sector_count = bio_sectors(bio); - else { - /* all FLUSH bio's reaching here should be empty */ - WARN_ON_ONCE(bio_has_data(bio)); + } else { + ci.bio = &ci.md->flush_bio; ci.sector_count = 1; } - ci.idx = bio->bi_idx; start_io_acct(ci.io); while (ci.sector_count && !error) { - if (!(bio->bi_rw & REQ_FLUSH)) + if (!is_flush) error = __clone_and_map(&ci); else error = __clone_and_map_flush(&ci); @@ -1419,22 +1398,14 @@ static int _dm_request(struct request_queue *q, struct bio *bio) part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio)); part_stat_unlock(); - /* - * If we're suspended or the thread is processing flushes - * we have to queue this io for later. - */ - if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) || - (bio->bi_rw & REQ_FLUSH)) { + /* if we're suspended, we have to queue this io for later */ + if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { up_read(&md->io_lock); - if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) && - bio_rw(bio) == READA) { + if (bio_rw(bio) != READA) + queue_io(md, bio); + else bio_io_error(bio); - return 0; - } - - queue_io(md, bio); - return 0; } @@ -1923,6 +1894,10 @@ static struct mapped_device *alloc_dev(int minor) if (!md->bdev) goto bad_bdev; + bio_init(&md->flush_bio); + md->flush_bio.bi_bdev = md->bdev; + md->flush_bio.bi_rw = WRITE_FLUSH; + /* Populate the mapping, nobody knows we exist yet */ spin_lock(&_minor_lock); old_md = idr_replace(&_minor_idr, md, minor); @@ -2313,37 +2288,6 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible) return r; } -static void process_flush(struct mapped_device *md, struct bio *bio) -{ - md->flush_error = 0; - - /* handle REQ_FLUSH */ - dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); - - bio_init(&md->flush_bio); - md->flush_bio.bi_bdev = md->bdev; - md->flush_bio.bi_rw = WRITE_FLUSH; - __split_and_process_bio(md, &md->flush_bio); - - dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE); - - /* if it's an empty flush or the preflush failed, we're done */ - if (!bio_has_data(bio) || md->flush_error) { - if (md->flush_error != DM_ENDIO_REQUEUE) - bio_endio(bio, md->flush_error); - else { - spin_lock_irq(&md->deferred_lock); - bio_list_add_head(&md->deferred, bio); - spin_unlock_irq(&md->deferred_lock); - } - return; - } - - /* issue data + REQ_FUA */ - bio->bi_rw &= ~REQ_FLUSH; - __split_and_process_bio(md, bio); -} - /* * Process the deferred bios */ @@ -2353,33 +2297,27 @@ static void dm_wq_work(struct work_struct *work) work); struct bio *c; - down_write(&md->io_lock); + down_read(&md->io_lock); while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) { spin_lock_irq(&md->deferred_lock); c = bio_list_pop(&md->deferred); spin_unlock_irq(&md->deferred_lock); - if (!c) { - clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); + if (!c) break; - } - up_write(&md->io_lock); + up_read(&md->io_lock); if (dm_request_based(md)) generic_make_request(c); - else { - if (c->bi_rw & REQ_FLUSH) - process_flush(md, c); - else - __split_and_process_bio(md, c); - } + else + __split_and_process_bio(md, c); - down_write(&md->io_lock); + down_read(&md->io_lock); } - up_write(&md->io_lock); + up_read(&md->io_lock); } static void dm_queue_flush(struct mapped_device *md) @@ -2511,17 +2449,12 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) * * To get all processes out of __split_and_process_bio in dm_request, * we take the write lock. To prevent any process from reentering - * __split_and_process_bio from dm_request, we set - * DMF_QUEUE_IO_TO_THREAD. - * - * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND - * and call flush_workqueue(md->wq). flush_workqueue will wait until - * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any - * further calls to __split_and_process_bio from dm_wq_work. + * __split_and_process_bio from dm_request and quiesce the thread + * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call + * flush_workqueue(md->wq). */ down_write(&md->io_lock); set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags); - set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags); up_write(&md->io_lock); /* -- cgit v1.1 From 05447420f99c1c44063c7f00054667c022cc1365 Mon Sep 17 00:00:00 2001 From: Kiyoshi Ueda Date: Wed, 8 Sep 2010 18:07:01 +0200 Subject: dm: fix locking context in queue_io() Now queue_io() is called from dec_pending(), which may be called with interrupts disabled, so queue_io() must not enable interrupts unconditionally and must save/restore the current interrupts status. Signed-off-by: Kiyoshi Ueda Signed-off-by: Jun'ichi Nomura Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- drivers/md/dm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 2011704..cd2f7e7 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -512,9 +512,11 @@ static void end_io_acct(struct dm_io *io) */ static void queue_io(struct mapped_device *md, struct bio *bio) { - spin_lock_irq(&md->deferred_lock); + unsigned long flags; + + spin_lock_irqsave(&md->deferred_lock, flags); bio_list_add(&md->deferred, bio); - spin_unlock_irq(&md->deferred_lock); + spin_unlock_irqrestore(&md->deferred_lock, flags); queue_work(md->wq, &md->work); } -- cgit v1.1 From b372d360df6deaf79a58a02fa0cc0d7e0aa3e92f Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 8 Sep 2010 18:07:01 +0200 Subject: dm: convey that all flushes are processed as empty Rename __clone_and_map_flush to __clone_and_map_empty_flush for added clarity. Simplify logic associated with REQ_FLUSH conditionals. Introduce a BUG_ON() and add a few more helpful comments to the code so that it is clear that all flushes are empty. Cleanup __split_and_process_bio() so that an empty flush isn't processed by a 'sector_count' focused while loop. Signed-off-by: Mike Snitzer Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- drivers/md/dm.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index cd2f7e7..f934e98 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -621,16 +621,17 @@ static void dec_pending(struct dm_io *io, int error) if (io_error == DM_ENDIO_REQUEUE) return; - if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) { - trace_block_bio_complete(md->queue, bio); - bio_endio(bio, io_error); - } else { + if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) { /* * Preflush done for flush with data, reissue * without REQ_FLUSH. */ bio->bi_rw &= ~REQ_FLUSH; queue_io(md, bio); + } else { + /* done with normal IO or empty flush */ + trace_block_bio_complete(md->queue, bio); + bio_endio(bio, io_error); } } } @@ -1132,16 +1133,15 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti, __issue_target_request(ci, ti, request_nr, len); } -static int __clone_and_map_flush(struct clone_info *ci) +static int __clone_and_map_empty_flush(struct clone_info *ci) { unsigned target_nr = 0; struct dm_target *ti; + BUG_ON(bio_has_data(ci->bio)); while ((ti = dm_table_get_target(ci->map, target_nr++))) __issue_target_requests(ci, ti, ti->num_flush_requests, 0); - ci->sector_count = 0; - return 0; } @@ -1282,7 +1282,6 @@ static int __clone_and_map(struct clone_info *ci) */ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) { - bool is_flush = bio->bi_rw & REQ_FLUSH; struct clone_info ci; int error = 0; @@ -1302,20 +1301,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio) ci.sector = bio->bi_sector; ci.idx = bio->bi_idx; - if (!is_flush) { + start_io_acct(ci.io); + if (bio->bi_rw & REQ_FLUSH) { + ci.bio = &ci.md->flush_bio; + ci.sector_count = 0; + error = __clone_and_map_empty_flush(&ci); + /* dec_pending submits any data associated with flush */ + } else { ci.bio = bio; ci.sector_count = bio_sectors(bio); - } else { - ci.bio = &ci.md->flush_bio; - ci.sector_count = 1; - } - - start_io_acct(ci.io); - while (ci.sector_count && !error) { - if (!is_flush) + while (ci.sector_count && !error) error = __clone_and_map(&ci); - else - error = __clone_and_map_flush(&ci); } /* drop the extra reference count */ -- cgit v1.1 From 8786fb70ccb36c7cff64680bb80c46d3a09d44db Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 16 Sep 2010 08:27:34 +0200 Subject: aic7xxx_old: removed unused 'req' variable After the patch "block: remove spurious uses of REQ_HARDBARRIER", we no longer use 'req' in aic7xxx_buildscb(). Kill it. Reported-by: Stephen Rothwell Signed-off-by: Jens Axboe --- drivers/scsi/aic7xxx_old.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers') diff --git a/drivers/scsi/aic7xxx_old.c b/drivers/scsi/aic7xxx_old.c index e1cd606..aee73fa 100644 --- a/drivers/scsi/aic7xxx_old.c +++ b/drivers/scsi/aic7xxx_old.c @@ -10119,7 +10119,6 @@ static void aic7xxx_buildscb(struct aic7xxx_host *p, struct scsi_cmnd *cmd, struct aic_dev_data *aic_dev = cmd->device->hostdata; struct scsi_device *sdptr = cmd->device; unsigned char tindex = TARGET_INDEX(cmd); - struct request *req = cmd->request; int use_sg; mask = (0x01 << tindex); -- cgit v1.1 From dd3932eddf428571762596e17b65f5dc92ca361b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 16 Sep 2010 20:51:46 +0200 Subject: block: remove BLKDEV_IFL_WAIT All the blkdev_issue_* helpers can only sanely be used for synchronous caller. To issue cache flushes or barriers asynchronously the caller needs to set up a bio by itself with a completion callback to move the asynchronous state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always specified when calling blkdev_issue_* and also remove the now unused flags argument to blkdev_issue_flush and blkdev_issue_zeroout. For blkdev_issue_discard we need to keep it for the secure discard flag, which gains a more descriptive name and loses the bitops vs flag confusion. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_int.h | 3 +-- drivers/block/drbd/drbd_receiver.c | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 352441b..c2ef476 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -2321,8 +2321,7 @@ static inline void drbd_md_flush(struct drbd_conf *mdev) if (test_bit(MD_NO_BARRIER, &mdev->flags)) return; - r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL, - BLKDEV_IFL_WAIT); + r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL); if (r) { set_bit(MD_NO_BARRIER, &mdev->flags); dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r); diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 081522d..df15e7f 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -975,7 +975,7 @@ static enum finish_epoch drbd_flush_after_epoch(struct drbd_conf *mdev, struct d if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) { rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL, - NULL, BLKDEV_IFL_WAIT); + NULL); if (rv) { dev_err(DEV, "local disk flush failed with status %d\n", rv); /* would rather check on EOPNOTSUPP, but that is not reliable. -- cgit v1.1 From 005a1d15f5a6b2bb4ada80349513effbf22b4588 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 22 Oct 2010 10:58:33 +0200 Subject: xen-blkfront: disable barrier/flush write support The driver doesn't handle empty flushes. Disable barrier/flush write support until this is fixed up. Signed-off-by: Jens Axboe --- drivers/block/xen-blkfront.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers') diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index f2ffc46..739b4c1 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1067,8 +1067,15 @@ static void blkfront_connect(struct blkfront_info *info) * If there are barriers, then we use flush. */ info->feature_flush = 0; + + /* + * The driver doesn't properly handled empty flushes, so + * lets disable barrier support for now. + */ +#if 0 if (!err && barrier) info->feature_flush = REQ_FLUSH; +#endif err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size); if (err) { -- cgit v1.1