diff options
author | Christoph Hellwig <hch@lst.de> | 2024-06-17 08:04:40 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2024-06-19 07:58:28 -0600 |
commit | 1122c0c1cc71f740fa4d5f14f239194e06a1d5e7 (patch) | |
tree | 690fcda48991904d6916c6f6e0f2205e37511531 | |
parent | 70905f8706b62113ae32c8df721384ff6ffb6c6a (diff) |
block: move cache control settings out of queue->flags
Move the cache control settings into the queue_limits so that the flags
can be set atomically with the device queue frozen.
Add new features and flags field for the driver set flags, and internal
(usually sysfs-controlled) flags in the block layer. Note that we'll
eventually remove enough field from queue_limits to bring it back to the
previous size.
The disable flag is inverted compared to the previous meaning, which
means it now survives a rescan, similar to the max_sectors and
max_discard_sectors user limits.
The FLUSH and FUA flags are now inherited by blk_stack_limits, which
simplified the code in dm a lot, but also causes a slight behavior
change in that dm-switch and dm-unstripe now advertise a write cache
despite setting num_flush_bios to 0. The I/O path will handle this
gracefully, but as far as I can tell the lack of num_flush_bios
and thus flush support is a pre-existing data integrity bug in those
targets that really needs fixing, after which a non-zero num_flush_bios
should be required in dm for targets that map to underlying devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
29 files changed, 227 insertions, 206 deletions
diff --git a/Documentation/block/writeback_cache_control.rst b/Documentation/block/writeback_cache_control.rst index b208488d0aae..c575e08beda8 100644 --- a/Documentation/block/writeback_cache_control.rst +++ b/Documentation/block/writeback_cache_control.rst @@ -46,41 +46,50 @@ worry if the underlying devices need any explicit cache flushing and how the Forced Unit Access is implemented. The REQ_PREFLUSH and REQ_FUA flags may both be set on a single bio. +Feature settings for block drivers +---------------------------------- -Implementation details for bio based block drivers --------------------------------------------------------------- +For devices that do not support volatile write caches there is no driver +support required, the block layer completes empty REQ_PREFLUSH requests before +entering the driver and strips off the REQ_PREFLUSH and REQ_FUA bits from +requests that have a payload. -These drivers will always see the REQ_PREFLUSH and REQ_FUA bits as they sit -directly below the submit_bio interface. For remapping drivers the REQ_FUA -bits need to be propagated to underlying devices, and a global flush needs -to be implemented for bios with the REQ_PREFLUSH bit set. For real device -drivers that do not have a volatile cache the REQ_PREFLUSH and REQ_FUA bits -on non-empty bios can simply be ignored, and REQ_PREFLUSH requests without -data can be completed successfully without doing any work. Drivers for -devices with volatile caches need to implement the support for these -flags themselves without any help from the block layer. +For devices with volatile write caches the driver needs to tell the block layer +that it supports flushing caches by setting the + BLK_FEAT_WRITE_CACHE -Implementation details for request_fn based block drivers ---------------------------------------------------------- +flag in the queue_limits feature field. For devices that also support the FUA +bit the block layer needs to be told to pass on the REQ_FUA bit by also setting +the -For devices that do not support volatile write caches there is no driver -support required, the block layer completes empty REQ_PREFLUSH requests before -entering the driver and strips off the REQ_PREFLUSH and REQ_FUA bits from -requests that have a payload. For devices with volatile write caches the -driver needs to tell the block layer that it supports flushing caches by -doing:: + BLK_FEAT_FUA + +flag in the features field of the queue_limits structure. + +Implementation details for bio based block drivers +-------------------------------------------------- + +For bio based drivers the REQ_PREFLUSH and REQ_FUA bit are simplify passed on +to the driver if the drivers sets the BLK_FEAT_WRITE_CACHE flag and the drivers +needs to handle them. + +*NOTE*: The REQ_FUA bit also gets passed on when the BLK_FEAT_FUA flags is +_not_ set. Any bio based driver that sets BLK_FEAT_WRITE_CACHE also needs to +handle REQ_FUA. - blk_queue_write_cache(sdkp->disk->queue, true, false); +For remapping drivers the REQ_FUA bits need to be propagated to underlying +devices, and a global flush needs to be implemented for bios with the +REQ_PREFLUSH bit set. -and handle empty REQ_OP_FLUSH requests in its prep_fn/request_fn. Note that -REQ_PREFLUSH requests with a payload are automatically turned into a sequence -of an empty REQ_OP_FLUSH request followed by the actual write by the block -layer. For devices that also support the FUA bit the block layer needs -to be told to pass through the REQ_FUA bit using:: +Implementation details for blk-mq drivers +----------------------------------------- - blk_queue_write_cache(sdkp->disk->queue, true, true); +When the BLK_FEAT_WRITE_CACHE flag is set, REQ_OP_WRITE | REQ_PREFLUSH requests +with a payload are automatically turned into a sequence of a REQ_OP_FLUSH +request followed by the actual write by the block layer. -and the driver must handle write requests that have the REQ_FUA bit set -in prep_fn/request_fn. If the FUA bit is not natively supported the block -layer turns it into an empty REQ_OP_FLUSH request after the actual write. +When the BLK_FEAT_FUA flags is set, the REQ_FUA bit simplify passed on for the +REQ_OP_WRITE request, else a REQ_OP_FLUSH request is sent by the block layer +after the completion of the write request for bio submissions with the REQ_FUA +bit set. diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index cdcb75a68989..19e01691ea0e 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -835,6 +835,7 @@ static int ubd_add(int n, char **error_out) struct queue_limits lim = { .max_segments = MAX_SG, .seg_boundary_mask = PAGE_SIZE - 1, + .features = BLK_FEAT_WRITE_CACHE, }; struct gendisk *disk; int err = 0; @@ -882,7 +883,6 @@ static int ubd_add(int n, char **error_out) } blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); - blk_queue_write_cache(disk->queue, true, false); disk->major = UBD_MAJOR; disk->first_minor = n << UBD_SHIFT; disk->minors = 1 << UBD_SHIFT; diff --git a/block/blk-core.c b/block/blk-core.c index 82c3ae22d76d..2b45a4df9a1a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -782,7 +782,7 @@ void submit_bio_noacct(struct bio *bio) if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_WRITE && bio_op(bio) != REQ_OP_ZONE_APPEND)) goto end_io; - if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) { + if (!bdev_write_cache(bdev)) { bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA); if (!bio_sectors(bio)) { status = BLK_STS_OK; diff --git a/block/blk-flush.c b/block/blk-flush.c index 2234f8b3fc05..30b9d5033a2b 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -381,8 +381,8 @@ static void blk_rq_init_flush(struct request *rq) bool blk_insert_flush(struct request *rq) { struct request_queue *q = rq->q; - unsigned long fflags = q->queue_flags; /* may change, cache */ struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx); + bool supports_fua = q->limits.features & BLK_FEAT_FUA; unsigned int policy = 0; /* FLUSH/FUA request must never be merged */ @@ -394,11 +394,10 @@ bool blk_insert_flush(struct request *rq) /* * Check which flushes we need to sequence for this operation. */ - if (fflags & (1UL << QUEUE_FLAG_WC)) { + if (blk_queue_write_cache(q)) { if (rq->cmd_flags & REQ_PREFLUSH) policy |= REQ_FSEQ_PREFLUSH; - if (!(fflags & (1UL << QUEUE_FLAG_FUA)) && - (rq->cmd_flags & REQ_FUA)) + if ((rq->cmd_flags & REQ_FUA) && !supports_fua) policy |= REQ_FSEQ_POSTFLUSH; } @@ -407,7 +406,7 @@ bool blk_insert_flush(struct request *rq) * REQ_PREFLUSH and FUA for the driver. */ rq->cmd_flags &= ~REQ_PREFLUSH; - if (!(fflags & (1UL << QUEUE_FLAG_FUA))) + if (!supports_fua) rq->cmd_flags &= ~REQ_FUA; /* diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 770c0c2b72fa..e8b9db7c30c4 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -93,8 +93,6 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(INIT_DONE), QUEUE_FLAG_NAME(STABLE_WRITES), QUEUE_FLAG_NAME(POLL), - QUEUE_FLAG_NAME(WC), - QUEUE_FLAG_NAME(FUA), QUEUE_FLAG_NAME(DAX), QUEUE_FLAG_NAME(STATS), QUEUE_FLAG_NAME(REGISTERED), diff --git a/block/blk-settings.c b/block/blk-settings.c index f11c8676eb4c..536ee202fcdc 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -261,6 +261,9 @@ static int blk_validate_limits(struct queue_limits *lim) lim->misaligned = 0; } + if (!(lim->features & BLK_FEAT_WRITE_CACHE)) + lim->features &= ~BLK_FEAT_FUA; + err = blk_validate_integrity_limits(lim); if (err) return err; @@ -454,6 +457,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, { unsigned int top, bottom, alignment, ret = 0; + t->features |= (b->features & BLK_FEAT_INHERIT_MASK); + t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); t->max_user_sectors = min_not_zero(t->max_user_sectors, b->max_user_sectors); @@ -711,30 +716,6 @@ void blk_set_queue_depth(struct request_queue *q, unsigned int depth) } EXPORT_SYMBOL(blk_set_queue_depth); -/** - * blk_queue_write_cache - configure queue's write cache - * @q: the request queue for the device - * @wc: write back cache on or off - * @fua: device supports FUA writes, if true - * - * Tell the block layer about the write cache of @q. - */ -void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) -{ - if (wc) { - blk_queue_flag_set(QUEUE_FLAG_HW_WC, q); - blk_queue_flag_set(QUEUE_FLAG_WC, q); - } else { - blk_queue_flag_clear(QUEUE_FLAG_HW_WC, q); - blk_queue_flag_clear(QUEUE_FLAG_WC, q); - } - if (fua) - blk_queue_flag_set(QUEUE_FLAG_FUA, q); - else - blk_queue_flag_clear(QUEUE_FLAG_FUA, q); -} -EXPORT_SYMBOL_GPL(blk_queue_write_cache); - int bdev_alignment_offset(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 5c787965b7d0..4f524c1d5e08 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -423,32 +423,41 @@ static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page, static ssize_t queue_wc_show(struct request_queue *q, char *page) { - if (test_bit(QUEUE_FLAG_WC, &q->queue_flags)) - return sprintf(page, "write back\n"); - - return sprintf(page, "write through\n"); + if (q->limits.features & BLK_FLAGS_WRITE_CACHE_DISABLED) + return sprintf(page, "write through\n"); + return sprintf(page, "write back\n"); } static ssize_t queue_wc_store(struct request_queue *q, const char *page, size_t count) { + struct queue_limits lim; + bool disable; + int err; + if (!strncmp(page, "write back", 10)) { - if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags)) - return -EINVAL; - blk_queue_flag_set(QUEUE_FLAG_WC, q); + disable = false; } else if (!strncmp(page, "write through", 13) || - !strncmp(page, "none", 4)) { - blk_queue_flag_clear(QUEUE_FLAG_WC, q); + !strncmp(page, "none", 4)) { + disable = true; } else { return -EINVAL; } + lim = queue_limits_start_update(q); + if (disable) + lim.flags |= BLK_FLAGS_WRITE_CACHE_DISABLED; + else + lim.flags &= ~BLK_FLAGS_WRITE_CACHE_DISABLED; + err = queue_limits_commit_update(q, &lim); + if (err) + return err; return count; } static ssize_t queue_fua_show(struct request_queue *q, char *page) { - return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags)); + return sprintf(page, "%u\n", !!(q->limits.features & BLK_FEAT_FUA)); } static ssize_t queue_dax_show(struct request_queue *q, char *page) diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 64472134dd26..1a5e4b049ecd 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -206,8 +206,8 @@ static void wbt_rqw_done(struct rq_wb *rwb, struct rq_wait *rqw, */ if (wb_acct & WBT_DISCARD) limit = rwb->wb_background; - else if (test_bit(QUEUE_FLAG_WC, &rwb->rqos.disk->queue->queue_flags) && - !wb_recent_wait(rwb)) + else if (blk_queue_write_cache(rwb->rqos.disk->queue) && + !wb_recent_wait(rwb)) limit = 0; else limit = rwb->wb_normal; diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 113b441d4d36..bf42a46781fa 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2697,6 +2697,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig * connect. */ .max_hw_sectors = DRBD_MAX_BIO_SIZE_SAFE >> 8, + .features = BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA, }; device = minor_to_device(minor); @@ -2736,7 +2737,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig disk->private_data = device; blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue); - blk_queue_write_cache(disk->queue, true, true); device->md_io.page = alloc_page(GFP_KERNEL); if (!device->md_io.page) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 8991de8fb1bb..08d0fc7f17b7 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -985,6 +985,9 @@ static int loop_reconfigure_limits(struct loop_device *lo, unsigned short bsize) lim.logical_block_size = bsize; lim.physical_block_size = bsize; lim.io_min = bsize; + lim.features &= ~BLK_FEAT_WRITE_CACHE; + if (file->f_op->fsync && !(lo->lo_flags & LO_FLAGS_READ_ONLY)) + lim.features |= BLK_FEAT_WRITE_CACHE; if (!backing_bdev || bdev_nonrot(backing_bdev)) blk_queue_flag_set(QUEUE_FLAG_NONROT, lo->lo_queue); else @@ -1078,9 +1081,6 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode, lo->old_gfp_mask = mapping_gfp_mask(mapping); mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); - if (!(lo->lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) - blk_queue_write_cache(lo->lo_queue, true, false); - error = loop_reconfigure_limits(lo, config->block_size); if (WARN_ON_ONCE(error)) goto out_unlock; @@ -1131,9 +1131,6 @@ static void __loop_clr_fd(struct loop_device *lo, bool release) struct file *filp; gfp_t gfp = lo->old_gfp_mask; - if (test_bit(QUEUE_FLAG_WC, &lo->lo_queue->queue_flags)) - blk_queue_write_cache(lo->lo_queue, false, false); - /* * Freeze the request queue when unbinding on a live file descriptor and * thus an open device. When called from ->release we are guaranteed diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 44b8c671921e..cb1c86a6a3fb 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -342,12 +342,14 @@ static int __nbd_set_size(struct nbd_device *nbd, loff_t bytesize, lim.max_hw_discard_sectors = UINT_MAX; else lim.max_hw_discard_sectors = 0; - if (!(nbd->config->flags & NBD_FLAG_SEND_FLUSH)) - blk_queue_write_cache(nbd->disk->queue, false, false); - else if (nbd->config->flags & NBD_FLAG_SEND_FUA) - blk_queue_write_cache(nbd->disk->queue, true, true); - else - blk_queue_write_cache(nbd->disk->queue, true, false); + if (!(nbd->config->flags & NBD_FLAG_SEND_FLUSH)) { + lim.features &= ~(BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA); + } else if (nbd->config->flags & NBD_FLAG_SEND_FUA) { + lim.features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA; + } else { + lim.features |= BLK_FEAT_WRITE_CACHE; + lim.features &= ~BLK_FEAT_FUA; + } lim.logical_block_size = blksize; lim.physical_block_size = blksize; error = queue_limits_commit_update(nbd->disk->queue, &lim); diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index 75f189e42f88..21f9d256e884 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -1928,6 +1928,13 @@ static int null_add_dev(struct nullb_device *dev) goto out_cleanup_tags; } + if (dev->cache_size > 0) { + set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); + lim.features |= BLK_FEAT_WRITE_CACHE; + if (dev->fua) + lim.features |= BLK_FEAT_FUA; + } + nullb->disk = blk_mq_alloc_disk(nullb->tag_set, &lim, nullb); if (IS_ERR(nullb->disk)) { rv = PTR_ERR(nullb->disk); @@ -1940,11 +1947,6 @@ static int null_add_dev(struct nullb_device *dev) nullb_setup_bwtimer(nullb); } - if (dev->cache_size > 0) { - set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); - blk_queue_write_cache(nullb->q, true, dev->fua); - } - nullb->q->queuedata = nullb; blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q); diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c index b810ac0a5c4b..8b73cf459b59 100644 --- a/drivers/block/ps3disk.c +++ b/drivers/block/ps3disk.c @@ -388,9 +388,8 @@ static int ps3disk_probe(struct ps3_system_bus_device *_dev) .max_segments = -1, .max_segment_size = dev->bounce_size, .dma_alignment = dev->blk_size - 1, + .features = BLK_FEAT_WRITE_CACHE, }; - - struct request_queue *queue; struct gendisk *gendisk; if (dev->blk_size < 512) { @@ -447,10 +446,6 @@ static int ps3disk_probe(struct ps3_system_bus_device *_dev) goto fail_free_tag_set; } - queue = gendisk->queue; - - blk_queue_write_cache(queue, true, false); - priv->gendisk = gendisk; gendisk->major = ps3disk_major; gendisk->first_minor = devidx * PS3DISK_MINORS; diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index b7ffe03c6160..02c4b1731827 100644 --- a/drivers/block/rnbd/rnbd-clt.c +++ b/drivers/block/rnbd/rnbd-clt.c @@ -1389,6 +1389,12 @@ static int rnbd_client_setup_device(struct rnbd_clt_dev *dev, le32_to_cpu(rsp->max_discard_sectors); } + if (rsp->cache_policy & RNBD_WRITEBACK) { + lim.features |= BLK_FEAT_WRITE_CACHE; + if (rsp->cache_policy & RNBD_FUA) + lim.features |= BLK_FEAT_FUA; + } + dev->gd = blk_mq_alloc_disk(&dev->sess->tag_set, &lim, dev); if (IS_ERR(dev->gd)) return PTR_ERR(dev->gd); @@ -1397,10 +1403,6 @@ static int rnbd_client_setup_device(struct rnbd_clt_dev *dev, blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, dev->queue); blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, dev->queue); - blk_queue_write_cache(dev->queue, - !!(rsp->cache_policy & RNBD_WRITEBACK), - !!(rsp->cache_policy & RNBD_FUA)); - return rnbd_clt_setup_gen_disk(dev, rsp, idx); } diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 4e159948c912..e45c65c1848d 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -487,8 +487,6 @@ static void ublk_dev_param_basic_apply(struct ublk_device *ub) struct request_queue *q = ub->ub_disk->queue; const struct ublk_param_basic *p = &ub->params.basic; - blk_queue_write_cache(q, p->attrs & UBLK_ATTR_VOLATILE_CACHE, - p->attrs & UBLK_ATTR_FUA); if (p->attrs & UBLK_ATTR_ROTATIONAL) blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); else @@ -2210,6 +2208,12 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd) lim.max_zone_append_sectors = p->max_zone_append_sectors; } + if (ub->params.basic.attrs & UBLK_ATTR_VOLATILE_CACHE) { + lim.features |= BLK_FEAT_WRITE_CACHE; + if (ub->params.basic.attrs & UBLK_ATTR_FUA) + lim.features |= BLK_FEAT_FUA; + } + if (wait_for_completion_interruptible(&ub->completion) != 0) return -EINTR; diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 378b241911ca..b1a3c2935285 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1100,6 +1100,7 @@ cache_type_store(struct device *dev, struct device_attribute *attr, struct gendisk *disk = dev_to_disk(dev); struct virtio_blk *vblk = disk->private_data; struct virtio_device *vdev = vblk->vdev; + struct queue_limits lim; int i; BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); @@ -1108,7 +1109,17 @@ cache_type_store(struct device *dev, struct device_attribute *attr, return i; virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); - blk_queue_write_cache(disk->queue, virtblk_get_cache_mode(vdev), false); + + lim = queue_limits_start_update(disk->queue); + if (virtblk_get_cache_mode(vdev)) + lim.features |= BLK_FEAT_WRITE_CACHE; + else + lim.features &= ~BLK_FEAT_WRITE_CACHE; + blk_mq_freeze_queue(disk->queue); + i = queue_limits_commit_update(disk->queue, &lim); + blk_mq_unfreeze_queue(disk->queue); + if (i) + return i; return count; } @@ -1504,6 +1515,9 @@ static int virtblk_probe(struct virtio_device *vdev) if (err) goto out_free_tags; + if (virtblk_get_cache_mode(vdev)) + lim.features |= BLK_FEAT_WRITE_CACHE; + vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk); if (IS_ERR(vblk->disk)) { err = PTR_ERR(vblk->disk); @@ -1519,10 +1533,6 @@ static int virtblk_probe(struct virtio_device *vdev) vblk->disk->fops = &virtblk_fops; vblk->index = index; - /* configure queue flush support */ - blk_queue_write_cache(vblk->disk->queue, virtblk_get_cache_mode(vdev), - false); - /* If disk is read-only in the host, the guest should obey */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) set_disk_ro(vblk->disk, 1); diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 851b03844edd..9aafce3e5987 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -959,6 +959,12 @@ static void blkif_set_queue_limits(const struct blkfront_info *info, lim->max_secure_erase_sectors = UINT_MAX; } + if (info->feature_flush) { + lim->features |= BLK_FEAT_WRITE_CACHE; + if (info->feature_fua) + lim->features |= BLK_FEAT_FUA; + } + /* Hard sector size and max sectors impersonate the equiv. hardware. */ lim->logical_block_size = info->sector_size; lim->physical_block_size = info->physical_sector_size; @@ -987,8 +993,6 @@ static const char *flush_info(struct blkfront_info *info) static void xlvbd_flush(struct blkfront_info *info) { - blk_queue_write_cache(info->rq, info->feature_flush ? true : false, - info->feature_fua ? true : false); pr_info("blkfront: %s: %s %s %s %s %s %s %s\n", info->gd->disk_name, flush_info(info), "persistent grants:", info->feature_persistent ? diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 4d11fc664cb0..cb6595c8b551 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -897,7 +897,6 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size, sector_t sectors, struct block_device *cached_bdev, const struct block_device_operations *ops) { - struct request_queue *q; const size_t max_stripes = min_t(size_t, INT_MAX, SIZE_MAX / sizeof(atomic_t)); struct queue_limits lim = { @@ -909,6 +908,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size, .io_min = block_size, .logical_block_size = block_size, .physical_block_size = block_size, + .features = BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA, }; uint64_t n; int idx; @@ -975,12 +975,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size, d->disk->fops = ops; d->disk->private_data = d; - q = d->disk->queue; - blk_queue_flag_set(QUEUE_FLAG_NONROT, d->disk->queue); - - blk_queue_write_cache(q, true, true); - return 0; out_bioset_exit: diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index fd789eeb62d9..03abdae64682 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1686,34 +1686,16 @@ combine_limits: return validate_hardware_logical_block_alignment(t, limits); } -static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) -{ - unsigned long flush = (unsigned long) data; - struct request_queue *q = bdev_get_queue(dev->bdev); - - return (q->queue_flags & flush); -} - -static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush) +/* + * Check if a target requires flush support even if none of the underlying + * devices need it (e.g. to persist target-specific metadata). + */ +static bool dm_table_supports_flush(struct dm_table *t) { - /* - * Require at least one underlying device to support flushes. - * t->devices includes internal dm devices such as mirror logs - * so we need to use iterate_devices here, which targets - * supporting flushes must provide. - */ for (unsigned int i = 0; i < t->num_targets; i++) { struct dm_target *ti = dm_table_get_target(t, i); - if (!ti->num_flush_bios) - continue; - - if (ti->flush_supported) - return true; - - if (ti->type->iterate_devices && - ti->type->iterate_devices(ti, device_flush_capable, (void *) flush)) + if (ti->num_flush_bios && ti->flush_supported) return true; } @@ -1855,7 +1837,6 @@ static int device_requires_stable_pages(struct dm_target *ti, int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { - bool wc = false, fua = false; int r; if (dm_table_supports_nowait(t)) @@ -1876,12 +1857,8 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, if (!dm_table_supports_secure_erase(t)) limits->max_secure_erase_sectors = 0; - if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) { - wc = true; - if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA))) - fua = true; - } - blk_queue_write_cache(q, wc, fua); + if (dm_table_supports_flush(t)) + limits->features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA; if (dm_table_supports_dax(t, device_not_dax_capable)) { blk_queue_flag_set(QUEUE_FLAG_DAX, q); diff --git a/drivers/md/md.c b/drivers/md/md.c index 67ece2cd725f..2f4c5d1755d8 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5785,7 +5785,10 @@ struct mddev *md_alloc(dev_t dev, char *name) int partitioned; int shift; int unit; - int error ; + int error; + struct queue_limits lim = { + .features = BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA, + }; /* * Wait for any previous instance of this device to be completely @@ -5825,7 +5828,7 @@ struct mddev *md_alloc(dev_t dev, char *name) */ mddev->hold_active = UNTIL_STOP; - disk = blk_alloc_disk(NULL, NUMA_NO_NODE); + disk = blk_alloc_disk(&lim, NUMA_NO_NODE); if (IS_ERR(disk)) { error = PTR_ERR(disk); goto out_free_mddev; @@ -5843,7 +5846,6 @@ struct mddev *md_alloc(dev_t dev, char *name) disk->fops = &md_fops; disk->private_data = mddev; - blk_queue_write_cache(disk->queue, true, true); disk->events |= DISK_EVENT_MEDIA_CHANGE; mddev->gendisk = disk; error = add_disk(disk); diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index 367509b5b646..2c9963248fcb 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -2466,8 +2466,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, struct mmc_blk_data *md; int devidx, ret; char cap_str[10]; - bool cache_enabled = false; - bool fua_enabled = false; + unsigned int features = 0; devidx = ida_alloc_max(&mmc_blk_ida, max_devices - 1, GFP_KERNEL); if (devidx < 0) { @@ -2499,7 +2498,24 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, */ md->read_only = mmc_blk_readonly(card); - md->disk = mmc_init_queue(&md->queue, card); + if (mmc_host_cmd23(card->host)) { + if ((mmc_card_mmc(card) && + card->csd.mmca_vsn >= CSD_SPEC_VER_3) || + (mmc_card_sd(card) && + card->scr.cmds & SD_SCR_CMD23_SUPPORT)) + md->flags |= MMC_BLK_CMD23; + } + + if (md->flags & MMC_BLK_CMD23 && + ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) || + card->ext_csd.rel_sectors)) { + md->flags |= MMC_BLK_REL_WR; + features |= (BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA); + } else if (mmc_cache_enabled(card->host)) { + features |= BLK_FEAT_WRITE_CACHE; + } + + md->disk = mmc_init_queue(&md->queue, card, features); if (IS_ERR(md->disk)) { ret = PTR_ERR(md->disk); goto err_kfree; @@ -2539,26 +2555,6 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, set_capacity(md->disk, size); - if (mmc_host_cmd23(card->host)) { - if ((mmc_card_mmc(card) && - card->csd.mmca_vsn >= CSD_SPEC_VER_3) || - (mmc_card_sd(card) && - card->scr.cmds & SD_SCR_CMD23_SUPPORT)) - md->flags |= MMC_BLK_CMD23; - } - - if (md->flags & MMC_BLK_CMD23 && - ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) || - card->ext_csd.rel_sectors)) { - md->flags |= MMC_BLK_REL_WR; - fua_enabled = true; - cache_enabled = true; - } - if (mmc_cache_enabled(card->host)) - cache_enabled = true; - - blk_queue_write_cache(md->queue.queue, cache_enabled, fua_enabled); - string_get_size((u64)size, 512, STRING_UNITS_2, cap_str, sizeof(cap_str)); pr_info("%s: %s %s %s%s\n", diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 241cdc2b2a2a..97ff993d3157 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -344,10 +344,12 @@ static const struct blk_mq_ops mmc_mq_ops = { }; static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq, - struct mmc_card *card) + struct mmc_card *card, unsigned int features) { struct mmc_host *host = card->host; - struct queue_limits lim = { }; + struct queue_limits lim = { + .features = features, + }; struct gendisk *disk; if (mmc_can_erase(card)) @@ -413,10 +415,12 @@ static inline bool mmc_merge_capable(struct mmc_host *host) * mmc_init_queue - initialise a queue structure. * @mq: mmc queue * @card: mmc card to attach this queue + * @features: block layer features (BLK_FEAT_*) * * Initialise a MMC card request queue. */ -struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card) +struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, + unsigned int features) { struct mmc_host *host = card->host; struct gendisk *disk; @@ -460,7 +464,7 @@ struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card) return ERR_PTR(ret); - disk = mmc_alloc_disk(mq, card); + disk = mmc_alloc_disk(mq, card, features); if (IS_ERR(disk)) blk_mq_free_tag_set(&mq->tag_set); return disk; diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h index 9ade3bcbb714..1498840a4ea0 100644 --- a/drivers/mmc/core/queue.h +++ b/drivers/mmc/core/queue.h @@ -94,7 +94,8 @@ struct mmc_queue { struct work_struct complete_work; }; -struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card); +struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, + unsigned int features); extern void mmc_cleanup_queue(struct mmc_queue *); extern void mmc_queue_suspend(struct mmc_queue *); extern void mmc_queue_resume(struct mmc_queue *); diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c index 3caa0717d46c..1b9f57f231e8 100644 --- a/drivers/mtd/mtd_blkdevs.c +++ b/drivers/mtd/mtd_blkdevs.c @@ -336,6 +336,8 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) lim.logical_block_size = tr->blksize; if (tr->discard) lim.max_hw_discard_sectors = UINT_MAX; + if (tr->flush) + lim.features |= BLK_FEAT_WRITE_CACHE; /* Create gendisk */ gd = blk_mq_alloc_disk(new->tag_set, &lim, new); @@ -373,9 +375,6 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) spin_lock_init(&new->queue_lock); INIT_LIST_HEAD(&new->rq_list); - if (tr->flush) - blk_queue_write_cache(new->rq, true, false); - blk_queue_flag_set(QUEUE_FLAG_NONROT, new->rq); blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, new->rq); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 598fe2e89bda..aff818469c11 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -455,6 +455,7 @@ static int pmem_attach_disk(struct device *dev, .logical_block_size = pmem_sector_size(ndns), .physical_block_size = PAGE_SIZE, .max_hw_sectors = UINT_MAX, + .features = BLK_FEAT_WRITE_CACHE, }; int nid = dev_to_node(dev), fua; struct resource *res = &nsio->res; @@ -495,6 +496,8 @@ static int pmem_attach_disk(struct device *dev, dev_warn(dev, "unable to guarantee persistence of writes\n"); fua = 0; } + if (fua) + lim.features |= BLK_FEAT_FUA; if (!devm_request_mem_region(dev, res->start, resource_size(res), dev_name(&ndns->dev))) { @@ -543,7 +546,6 @@ static int pmem_attach_disk(struct device *dev, } pmem->virt_addr = addr; - blk_queue_write_cache(q, true, fua); blk_queue_flag_set(QUEUE_FLAG_NONROT, q); blk_queue_flag_set(QUEUE_FLAG_SYNCHRONOUS, q); if (pmem->pfn_flags & PFN_MAP) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 5a673fa5cb26..9fc5e36fe2e5 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2056,7 +2056,6 @@ static int nvme_update_ns_info_generic(struct nvme_ns *ns, static int nvme_update_ns_info_block(struct nvme_ns *ns, struct nvme_ns_info *info) { - bool vwc = ns->ctrl->vwc & NVME_CTRL_VWC_PRESENT; struct queue_limits lim; struct nvme_id_ns_nvm *nvm = NULL; struct nvme_zone_info zi = {}; @@ -2106,6 +2105,11 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns, ns->head->ids.csi == NVME_CSI_ZNS) nvme_update_zone_info(ns, &lim, &zi); + if (ns->ctrl->vwc & NVME_CTRL_VWC_PRESENT) + lim.features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA; + else + lim.features &= ~(BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA); + /* * Register a metadata profile for PI, or the plain non-integrity NVMe * metadata masquerading as Type 0 if supported, otherwise reject block @@ -2132,7 +2136,6 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns, if ((id->dlfeat & 0x7) == 0x1 && (id->dlfeat & (1 << 3))) ns->head->features |= NVME_NS_DEAC; set_disk_ro(ns->disk, nvme_ns_is_readonly(ns, info)); - blk_queue_write_cache(ns->disk->queue, vwc, vwc); set_bit(NVME_NS_READY, &ns->flags); blk_mq_unfreeze_queue(ns->disk->queue); diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 12c59db02539..3d0e23a0a4dd 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -521,7 +521,6 @@ static void nvme_requeue_work(struct work_struct *work) int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) { struct queue_limits lim; - bool vwc = false; mutex_init(&head->lock); bio_list_init(&head->requeue_list); @@ -562,11 +561,6 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) if (ctrl->tagset->nr_maps > HCTX_TYPE_POLL && ctrl->tagset->map[HCTX_TYPE_POLL].nr_queues) blk_queue_flag_set(QUEUE_FLAG_POLL, head->disk->queue); - - /* we need to propagate up the VMC settings */ - if (ctrl->vwc & NVME_CTRL_VWC_PRESENT) - vwc = true; - blk_queue_write_cache(head->disk->queue, vwc, vwc); return 0; } diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 66f7d1e3429c..d8ee4a4d4a62 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -120,17 +120,18 @@ static const char *sd_cache_types[] = { "write back, no read (daft)" }; -static void sd_set_flush_flag(struct scsi_disk *sdkp) +static void sd_set_flush_flag(struct scsi_disk *sdkp, + struct queue_limits *lim) { - bool wc = false, fua = false; - if (sdkp->WCE) { - wc = true; + lim->features |= BLK_FEAT_WRITE_CACHE; if (sdkp->DPOFUA) - fua = true; + lim->features |= BLK_FEAT_FUA; + else + lim->features &= ~BLK_FEAT_FUA; + } else { + lim->features &= ~(BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA); } - - blk_queue_write_cache(sdkp->disk->queue, wc, fua); } static ssize_t @@ -168,9 +169,18 @@ cache_type_store(struct device *dev, struct device_attribute *attr, wce = (ct & 0x02) && !sdkp->write_prot ? 1 : 0; if (sdkp->cache_override) { + struct queue_limits lim; + sdkp->WCE = wce; sdkp->RCD = rcd; - sd_set_flush_flag(sdkp); + + lim = queue_limits_start_update(sdkp->disk->queue); + sd_set_flush_flag(sdkp, &lim); + blk_mq_freeze_queue(sdkp->disk->queue); + ret = queue_limits_commit_update(sdkp->disk->queue, &lim); + blk_mq_unfreeze_queue(sdkp->disk->queue); + if (ret) + return ret; return count; } @@ -3663,7 +3673,7 @@ static int sd_revalidate_disk(struct gendisk *disk) * We now have all cache related info, determine how we deal * with flush requests. */ - sd_set_flush_flag(sdkp); + sd_set_flush_flag(sdkp, &lim); /* Initial block count limit based on CDB TRANSFER LENGTH field size. */ dev_max = sdp->use_16_for_rw ? SD_MAX_XFER_BLOCKS : SD_DEF_XFER_BLOCKS; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0c247a716885..acdfe5122faa 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -282,6 +282,28 @@ static inline bool blk_op_is_passthrough(blk_opf_t op) return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT; } +/* flags set by the driver in queue_limits.features */ +enum { + /* supports a volatile write cache */ + BLK_FEAT_WRITE_CACHE = (1u << 0), + + /* supports passing on the FUA bit */ + BLK_FEAT_FUA = (1u << 1), +}; + +/* + * Flags automatically inherited when stacking limits. + */ +#define BLK_FEAT_INHERIT_MASK \ + (BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA) + + +/* internal flags in queue_limits.flags */ +enum { + /* do not send FLUSH or FUA command despite advertised write cache */ + BLK_FLAGS_WRITE_CACHE_DISABLED = (1u << 31), +}; + /* * BLK_BOUNCE_NONE: never bounce (default) * BLK_BOUNCE_HIGH: bounce all highmem pages @@ -292,6 +314,8 @@ enum blk_bounce { }; struct queue_limits { + unsigned int features; + unsigned int flags; enum blk_bounce bounce; unsigned long seg_boundary_mask; unsigned long virt_boundary_mask; @@ -536,12 +560,9 @@ struct request_queue { #define QUEUE_FLAG_ADD_RANDOM 10 /* Contributes to random pool */ #define QUEUE_FLAG_SYNCHRONOUS 11 /* always completes in submit context */ #define QUEUE_FLAG_SAME_FORCE 12 /* force complete on same CPU */ -#define QUEUE_FLAG_HW_WC 13 /* Write back caching supported */ #define QUEUE_FLAG_INIT_DONE 14 /* queue is initialized */ #define QUEUE_FLAG_STABLE_WRITES 15 /* don't modify blks until WB is done */ #define QUEUE_FLAG_POLL 16 /* IO polling enabled if set */ -#define QUEUE_FLAG_WC 17 /* Write back caching */ -#define QUEUE_FLAG_FUA 18 /* device supports FUA writes */ #define QUEUE_FLAG_DAX 19 /* device supports DAX */ #define QUEUE_FLAG_STATS 20 /* track IO start and completion times */ #define QUEUE_FLAG_REGISTERED 22 /* queue has been registered to a disk */ @@ -951,7 +972,6 @@ void queue_limits_stack_bdev(struct queue_limits *t, struct block_device *bdev, sector_t offset, const char *pfx); extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); -extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua); struct blk_independent_access_ranges * disk_alloc_independent_access_ranges(struct gendisk *disk, int nr_ia_ranges); @@ -1304,14 +1324,20 @@ static inline bool bdev_stable_writes(struct block_device *bdev) return test_bit(QUEUE_FLAG_STABLE_WRITES, &q->queue_flags); } +static inline bool blk_queue_write_cache(struct request_queue *q) +{ + return (q->limits.features & BLK_FEAT_WRITE_CACHE) && + !(q->limits.flags & BLK_FLAGS_WRITE_CACHE_DISABLED); +} + static inline bool bdev_write_cache(struct block_device *bdev) { - return test_bit(QUEUE_FLAG_WC, &bdev_get_queue(bdev)->queue_flags); + return blk_queue_write_cache(bdev_get_queue(bdev)); } static inline bool bdev_fua(struct block_device *bdev) { - return test_bit(QUEUE_FLAG_FUA, &bdev_get_queue(bdev)->queue_flags); + return bdev_get_queue(bdev)->limits.features & BLK_FEAT_FUA; } static inline bool bdev_nowait(struct block_device *bdev) |