From b508fc354f6d168ec18673d99d3bce9d6c1d9475 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 21 Dec 2016 11:20:45 +0100 Subject: nvme: update maintainers information Switch the new, shared nvme git repository, which is co-maintained by everyone involved with NVMe. Also add the nvme_ioctl.h UAPI header to the files list. Signed-off-by: Christoph Hellwig --- MAINTAINERS | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/MAINTAINERS b/MAINTAINERS index f6eb97b35e0f..9b279928461d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8852,17 +8852,22 @@ F: drivers/video/fbdev/nvidia/ NVM EXPRESS DRIVER M: Keith Busch M: Jens Axboe +M: Christoph Hellwig +M: Sagi Grimberg L: linux-nvme@lists.infradead.org -T: git git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git -W: https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux-block/ +T: git://git.infradead.org/nvme.git +W: http://git.infradead.org/nvme.git S: Supported F: drivers/nvme/host/ F: include/linux/nvme.h +F: include/uapi/linux/nvme_ioctl.h NVM EXPRESS TARGET DRIVER M: Christoph Hellwig M: Sagi Grimberg L: linux-nvme@lists.infradead.org +T: git://git.infradead.org/nvme.git +W: http://git.infradead.org/nvme.git S: Supported F: drivers/nvme/target/ -- cgit v1.2.3 From e6282aef7b89a11d26e731060c4409b7aac278bf Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Mon, 19 Dec 2016 11:37:50 -0500 Subject: nvme: simplify stripe quirk Some OEMs believe they own the Identify Controller vendor specific region and will repurpose it with their own values. While not common, we can't rely on the PCI VID:DID to tell use how to decode the field we reserved for this as the stripe size so we need to do something else for the list of devices using this quirk. The field was supposed to allow flexibility on the device's back-end striping, but it turned out that never materialized; the chunk is always the same as MDTS in the products subscribing to this quirk, so this patch removes the stripe_size field and sets the chunk to the max hw transfer size for the devices using this quirk. Signed-off-by: Keith Busch Signed-off-by: Christoph Hellwig --- drivers/nvme/host/core.c | 17 ++--------------- drivers/nvme/host/nvme.h | 1 - 2 files changed, 2 insertions(+), 16 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index b40cfb076f02..2fc86dc7a8df 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1193,8 +1193,8 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl, blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors); blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX)); } - if (ctrl->stripe_size) - blk_queue_chunk_sectors(q, ctrl->stripe_size >> 9); + if (ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) + blk_queue_chunk_sectors(q, ctrl->max_hw_sectors); blk_queue_virt_boundary(q, ctrl->page_size - 1); if (ctrl->vwc & NVME_CTRL_VWC_PRESENT) vwc = true; @@ -1250,19 +1250,6 @@ int nvme_init_identify(struct nvme_ctrl *ctrl) ctrl->max_hw_sectors = min_not_zero(ctrl->max_hw_sectors, max_hw_sectors); - if ((ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) && id->vs[3]) { - unsigned int max_hw_sectors; - - ctrl->stripe_size = 1 << (id->vs[3] + page_shift); - max_hw_sectors = ctrl->stripe_size >> (page_shift - 9); - if (ctrl->max_hw_sectors) { - ctrl->max_hw_sectors = min(max_hw_sectors, - ctrl->max_hw_sectors); - } else { - ctrl->max_hw_sectors = max_hw_sectors; - } - } - nvme_set_queue_limits(ctrl, ctrl->admin_q); ctrl->sgls = le32_to_cpu(id->sgls); ctrl->kas = le16_to_cpu(id->kas); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index bd5321441d12..6377e14586dc 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -135,7 +135,6 @@ struct nvme_ctrl { u32 page_size; u32 max_hw_sectors; - u32 stripe_size; u16 oncs; u16 vid; atomic_t abort_limit; -- cgit v1.2.3 From 9fa196e7fc7a0f12329d5346164abb27f026991c Mon Sep 17 00:00:00 2001 From: Max Gurtovoy Date: Mon, 19 Dec 2016 16:18:24 +0200 Subject: nvme/pci: Fix whitespace problem Convert to tabs and remove unneeded whitespaces. Signed-off-by: Max Gurtovoy Signed-off-by: Christoph Hellwig --- drivers/nvme/host/pci.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 2fd7dc2e8fc4..7d6c87028568 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -50,7 +50,7 @@ #define NVME_AQ_DEPTH 256 #define SQ_SIZE(depth) (depth * sizeof(struct nvme_command)) #define CQ_SIZE(depth) (depth * sizeof(struct nvme_completion)) - + /* * We handle AEN commands ourselves and don't even let the * block layer know about them. @@ -1909,10 +1909,10 @@ static int nvme_dev_map(struct nvme_dev *dev) if (!dev->bar) goto release; - return 0; + return 0; release: - pci_release_mem_regions(pdev); - return -ENODEV; + pci_release_mem_regions(pdev); + return -ENODEV; } static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id) -- cgit v1.2.3 From ff13b39ecf726715a96fcd3c23e50eb792ef6516 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Fri, 9 Dec 2016 12:08:58 -0500 Subject: nvme/pci: Delete misleading queue-wrap comment It is not theoretically possible for this driver to wrap twice while processing completions. The driver allocates only 'queue_depth - 1' tags, so there can never be more than that to reap when processing a completion queue. Removing this misleading comment makes it a little less likely people with broken controllers will blame the driver for their spurious interrupts. Signed-off-by: Keith Busch Signed-off-by: Christoph Hellwig --- drivers/nvme/host/pci.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 7d6c87028568..151ce59f4ffb 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -712,15 +712,8 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag) req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id); nvme_req(req)->result = cqe.result; blk_mq_complete_request(req, le16_to_cpu(cqe.status) >> 1); - } - /* If the controller ignores the cq head doorbell and continuously - * writes to the queue, it is theoretically possible to wrap around - * the queue twice and mistakenly return IRQ_NONE. Linux only - * requires that 0.1% of your interrupts are handled, so this isn't - * a big problem. - */ if (head == nvmeq->cq_head && phase == nvmeq->cq_phase) return; -- cgit v1.2.3 From 2c473a9d02fbe881506d5d43bc7edb776f2f46f5 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 6 Dec 2016 10:14:35 -0800 Subject: nvme/scsi: Remove START STOP emulation Now that the broken power state control is gone, it appears to serve no purpose. Just delete it. NVME devices don't have a concept of started vs stopped anyway. Signed-off-by: Andy Lutomirski Reviewed-by: Keith Busch Signed-off-by: Christoph Hellwig --- drivers/nvme/host/scsi.c | 27 --------------------------- 1 file changed, 27 deletions(-) diff --git a/drivers/nvme/host/scsi.c b/drivers/nvme/host/scsi.c index b71e95044b43..a5c09e703bd8 100644 --- a/drivers/nvme/host/scsi.c +++ b/drivers/nvme/host/scsi.c @@ -2160,30 +2160,6 @@ static int nvme_trans_synchronize_cache(struct nvme_ns *ns, return nvme_trans_status_code(hdr, nvme_sc); } -static int nvme_trans_start_stop(struct nvme_ns *ns, struct sg_io_hdr *hdr, - u8 *cmd) -{ - u8 immed, no_flush; - - immed = cmd[1] & 0x01; - no_flush = cmd[4] & 0x04; - - if (immed != 0) { - return nvme_trans_completion(hdr, SAM_STAT_CHECK_CONDITION, - ILLEGAL_REQUEST, SCSI_ASC_INVALID_CDB, - SCSI_ASCQ_CAUSE_NOT_REPORTABLE); - } else { - if (no_flush == 0) { - /* Issue NVME FLUSH command prior to START STOP UNIT */ - int res = nvme_trans_synchronize_cache(ns, hdr); - if (res) - return res; - } - - return 0; - } -} - static int nvme_trans_format_unit(struct nvme_ns *ns, struct sg_io_hdr *hdr, u8 *cmd) { @@ -2439,9 +2415,6 @@ static int nvme_scsi_translate(struct nvme_ns *ns, struct sg_io_hdr *hdr) case SECURITY_PROTOCOL_OUT: retcode = nvme_trans_security_protocol(ns, hdr, cmd); break; - case START_STOP: - retcode = nvme_trans_start_stop(ns, hdr, cmd); - break; case SYNCHRONIZE_CACHE: retcode = nvme_trans_synchronize_cache(ns, hdr); break; -- cgit v1.2.3 From c703489885218900579279cec4b4ab8e7fce383b Mon Sep 17 00:00:00 2001 From: James Smart Date: Tue, 20 Dec 2016 11:06:08 -0800 Subject: nvme/fc: correct some printk information Dan Carpenters's tool caught a pointer reference - should have been just ptr, not &ptr. Don't bother. Remove the pointer value in the printf. Its irrelevant. Signed-off-by: James Smart Reported-by: Dan Carpenter Signed-off-by: Christoph Hellwig --- drivers/nvme/host/fc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index 771e2e761872..827c2b57e5bb 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2401,8 +2401,8 @@ __nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts, WARN_ON_ONCE(!changed); dev_info(ctrl->ctrl.device, - "NVME-FC{%d}: new ctrl: NQN \"%s\" (%p)\n", - ctrl->cnum, ctrl->ctrl.opts->subsysnqn, &ctrl); + "NVME-FC{%d}: new ctrl: NQN \"%s\"\n", + ctrl->cnum, ctrl->ctrl.opts->subsysnqn); kref_get(&ctrl->ctrl.kref); -- cgit v1.2.3 From 17a1ec08ce7074f05795e5c32a3e5bc9a797bbf8 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Thu, 15 Dec 2016 14:20:48 +0100 Subject: nvme/fc: simplify error handling of nvme_fc_create_hw_io_queues Simplify the error handling of nvme_fc_create_hw_io_queues(), this saves us one variable and one level of indentation. Signed-off-by: Johannes Thumshirn Reviwed-by: James Smart Signed-off-by: Christoph Hellwig --- drivers/nvme/host/fc.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index 827c2b57e5bb..aa0bc60810a7 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -1491,19 +1491,20 @@ static int nvme_fc_create_hw_io_queues(struct nvme_fc_ctrl *ctrl, u16 qsize) { struct nvme_fc_queue *queue = &ctrl->queues[1]; - int i, j, ret; + int i, ret; for (i = 1; i < ctrl->queue_count; i++, queue++) { ret = __nvme_fc_create_hw_queue(ctrl, queue, i, qsize); - if (ret) { - for (j = i-1; j >= 0; j--) - __nvme_fc_delete_hw_queue(ctrl, - &ctrl->queues[j], j); - return ret; - } + if (ret) + goto delete_queues; } return 0; + +delete_queues: + for (; i >= 0; i--) + __nvme_fc_delete_hw_queue(ctrl, &ctrl->queues[i], i); + return ret; } static int -- cgit v1.2.3 From 6c73f949300f17851f53fa80c9d1611ccd6909d3 Mon Sep 17 00:00:00 2001 From: Daniel Verkamp Date: Fri, 9 Dec 2016 12:59:46 -0700 Subject: nvmet: fix KATO offset in Set Features The Set Features implementation for Keep Alive Timer was using the wrong structure when retrieving the KATO value; it was treating the Set Features command as a Property Set command. The NVMe spec defines the Keep Alive Timer feature as having one input in CDW11 (4 bytes at offset 44 in the command) whereas the code was reading 8 bytes at offset 48. Since the Linux NVMe over Fabrics host never sets this feature, this code has presumably never been tested. Signed-off-by: Daniel Verkamp Signed-off-by: Christoph Hellwig --- drivers/nvme/target/admin-cmd.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c index ec1ad2aa0a4c..95ae52390478 100644 --- a/drivers/nvme/target/admin-cmd.c +++ b/drivers/nvme/target/admin-cmd.c @@ -382,7 +382,6 @@ static void nvmet_execute_set_features(struct nvmet_req *req) { struct nvmet_subsys *subsys = req->sq->ctrl->subsys; u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10[0]); - u64 val; u32 val32; u16 status = 0; @@ -392,8 +391,7 @@ static void nvmet_execute_set_features(struct nvmet_req *req) (subsys->max_qid - 1) | ((subsys->max_qid - 1) << 16)); break; case NVME_FEAT_KATO: - val = le64_to_cpu(req->cmd->prop_set.value); - val32 = val & 0xffff; + val32 = le32_to_cpu(req->cmd->common.cdw10[1]); req->sq->ctrl->kato = DIV_ROUND_UP(val32, 1000); nvmet_set_result(req, req->sq->ctrl->kato); break; -- cgit v1.2.3 From 7c3a23b85cac5f3caa531f369c1e3a5f1a8b555f Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Fri, 9 Dec 2016 14:59:47 +0000 Subject: nvmet/fcloop: remove some logically dead code performing redundant ret checks The check to see if ret is non-zero and return this rather than count is redundant in two occassions. It is redundant because prior to this check, the return code ret is already checked for a non-zero error return value and we return from the function at that point. Signed-off-by: Colin Ian King Reviewed-off-by: James Smart Signed-off-by: Christoph Hellwig --- drivers/nvme/target/fcloop.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c index bcb8ebeb01c5..4e8e6a22bce1 100644 --- a/drivers/nvme/target/fcloop.c +++ b/drivers/nvme/target/fcloop.c @@ -845,7 +845,7 @@ fcloop_create_remote_port(struct device *dev, struct device_attribute *attr, rport->lport = nport->lport; nport->rport = rport; - return ret ? ret : count; + return count; } @@ -952,7 +952,7 @@ fcloop_create_target_port(struct device *dev, struct device_attribute *attr, tport->lport = nport->lport; nport->tport = tport; - return ret ? ret : count; + return count; } -- cgit v1.2.3 From 64d656a162d7ba49d6d1863e41407b0f95e19258 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 22 Dec 2016 19:20:45 +0100 Subject: block: add back plugging in __blkdev_direct_IO This allows sending larger than 1 MB requests to devices that support large I/O sizes. Signed-off-by: Christoph Hellwig Reported-by: Laurence Oberman Signed-off-by: Jens Axboe --- fs/block_dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 7c4507224ed6..206a92aab52e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -328,6 +328,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) struct file *file = iocb->ki_filp; struct inode *inode = bdev_file_inode(file); struct block_device *bdev = I_BDEV(inode); + struct blk_plug plug; struct blkdev_dio *dio; struct bio *bio; bool is_read = (iov_iter_rw(iter) == READ); @@ -353,6 +354,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) dio->multi_bio = false; dio->should_dirty = is_read && (iter->type == ITER_IOVEC); + blk_start_plug(&plug); for (;;) { bio->bi_bdev = bdev; bio->bi_iter.bi_sector = pos >> 9; @@ -394,6 +396,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) submit_bio(bio); bio = bio_alloc(GFP_KERNEL, nr_pages); } + blk_finish_plug(&plug); if (!dio->is_sync) return -EIOCBQUEUED; -- cgit v1.2.3 From 72c5296f9d64d8f5f27c2133e5f108a45a353d71 Mon Sep 17 00:00:00 2001 From: Jon Derrick Date: Tue, 20 Dec 2016 14:38:14 -0700 Subject: genhd: remove dead and duplicated scsi code blk_scsi_cmd_filter use was deprecated by 4beab5c6 and the SCSI macros are duplicated in blkdev.h, both likely reintroduced by a bad merge from 540eed56. Signed-off-by: Jon Derrick Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/genhd.h | 9 --------- 1 file changed, 9 deletions(-) diff --git a/include/linux/genhd.h b/include/linux/genhd.h index e0341af6950e..76f39754e7b0 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -146,15 +146,6 @@ enum { DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */ }; -#define BLK_SCSI_MAX_CMDS (256) -#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8)) - -struct blk_scsi_cmd_filter { - unsigned long read_ok[BLK_SCSI_CMD_PER_LONG]; - unsigned long write_ok[BLK_SCSI_CMD_PER_LONG]; - struct kobject kobj; -}; - struct disk_part_tbl { struct rcu_head rcu_head; int len; -- cgit v1.2.3 From 6c006a9d94bfb5cbcc5150e8fd7f45d3f92f3ee8 Mon Sep 17 00:00:00 2001 From: Chandan Rajendra Date: Sun, 25 Dec 2016 19:01:03 +0530 Subject: clean_bdev_aliases: Prevent cleaning blocks that are not in block range The first block to be cleaned may start at a non-zero page offset. In such a scenario clean_bdev_aliases() will end up cleaning blocks that do not fall in the range of blocks to be cleaned. This commit fixes the issue by skipping blocks that do not fall in valid block range. Signed-off-by: Chandan Rajendra Reviewed-by: Jan Kara Reviewed-by: Eryu Guan Signed-off-by: Jens Axboe --- fs/buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/buffer.c b/fs/buffer.c index d21771fcf7d3..0e87401cf335 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1660,7 +1660,7 @@ void clean_bdev_aliases(struct block_device *bdev, sector_t block, sector_t len) head = page_buffers(page); bh = head; do { - if (!buffer_mapped(bh)) + if (!buffer_mapped(bh) || (bh->b_blocknr < block)) goto next; if (bh->b_blocknr >= block + len) break; -- cgit v1.2.3 From f2e0a0b292682dd94274d6793d76656b41526147 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Mon, 2 Jan 2017 09:46:15 -0700 Subject: block: Make wbt_wait() definition consistent with declaration Fixes: e34cbd307477 ("blk-wbt: add general throttling mechanism") Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-wbt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 6e82769f4042..fd28c2806406 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -595,7 +595,7 @@ static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio) * in an irq held spinlock, if it holds one when calling this function. * If we do sleep, we'll release and re-grab it. */ -unsigned int wbt_wait(struct rq_wb *rwb, struct bio *bio, spinlock_t *lock) +enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio, spinlock_t *lock) { unsigned int ret = 0; -- cgit v1.2.3 From 9eca53508a157c6b6fdb6e06796902cf8a920d29 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Mon, 2 Jan 2017 09:48:47 -0700 Subject: block: Avoid that sparse complains about context imbalance in __wbt_wait() This patch does not change any functionality. Fixes: e34cbd307477 ("blk-wbt: add general throttling mechanism") Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-wbt.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/block/blk-wbt.c b/block/blk-wbt.c index fd28c2806406..f0a9c07b4c7a 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -544,6 +544,8 @@ static inline bool may_queue(struct rq_wb *rwb, struct rq_wait *rqw, * the timer to kick off queuing again. */ static void __wbt_wait(struct rq_wb *rwb, unsigned long rw, spinlock_t *lock) + __releases(lock) + __acquires(lock) { struct rq_wait *rqw = get_rq_wait(rwb, current_is_kswapd()); DEFINE_WAIT(wait); @@ -558,13 +560,12 @@ static void __wbt_wait(struct rq_wb *rwb, unsigned long rw, spinlock_t *lock) if (may_queue(rwb, rqw, &wait, rw)) break; - if (lock) + if (lock) { spin_unlock_irq(lock); - - io_schedule(); - - if (lock) + io_schedule(); spin_lock_irq(lock); + } else + io_schedule(); } while (1); finish_wait(&rqw->wait, &wait); -- cgit v1.2.3 From 7158339d4c1ede786c48fa5c062fa68df366ba94 Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Tue, 3 Jan 2017 17:51:33 -0500 Subject: block: fix up io_poll documentation /sys/block//queue/io_poll is a boolean. Fix the docs. Signed-off-by: Jeff Moyer Signed-off-by: Jens Axboe --- Documentation/block/queue-sysfs.txt | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 51642159aedb..c0a3bb5a6e4e 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -54,9 +54,9 @@ This is the hardware sector size of the device, in bytes. io_poll (RW) ------------ -When read, this file shows the total number of block IO polls and how -many returned success. Writing '0' to this file will disable polling -for this device. Writing any non-zero value will enable this feature. +When read, this file shows whether polling is enabled (1) or disabled +(0). Writing '0' to this file will disable polling for this device. +Writing any non-zero value will enable this feature. io_poll_delay (RW) ------------------ -- cgit v1.2.3