From e9c787e65c0c36529745be47d490d998b4b6e589 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 2 Jan 2017 21:55:26 +0300 Subject: [PATCH] scsi: allocate scsi_cmnd structures as part of struct request MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Rely on the new block layer functionality to allocate additional driver specific data behind struct request instead of implementing it in SCSI itѕelf. Signed-off-by: Christoph Hellwig Acked-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- drivers/scsi/hosts.c | 20 +-- drivers/scsi/scsi.c | 319 -------------------------------------- drivers/scsi/scsi_error.c | 17 +- drivers/scsi/scsi_lib.c | 122 ++++++++++----- drivers/scsi/scsi_priv.h | 8 +- include/scsi/scsi_host.h | 3 - 6 files changed, 95 insertions(+), 394 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 6d29c4ad9b15..831a1c8b9f89 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -230,19 +230,6 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, } } - /* - * Note that we allocate the freelist even for the MQ case for now, - * as we need a command set aside for scsi_reset_provider. Having - * the full host freelist and one command available for that is a - * little heavy-handed, but avoids introducing a special allocator - * just for this. Eventually the structure of scsi_reset_provider - * will need a major overhaul. - */ - error = scsi_setup_command_freelist(shost); - if (error) - goto out_destroy_tags; - - if (!shost->shost_gendev.parent) shost->shost_gendev.parent = dev ? dev : &platform_bus; if (!dma_dev) @@ -262,7 +249,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, error = device_add(&shost->shost_gendev); if (error) - goto out_destroy_freelist; + goto out_disable_runtime_pm; scsi_host_set_state(shost, SHOST_RUNNING); get_device(shost->shost_gendev.parent); @@ -312,13 +299,11 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, device_del(&shost->shost_dev); out_del_gendev: device_del(&shost->shost_gendev); - out_destroy_freelist: + out_disable_runtime_pm: device_disable_async_suspend(&shost->shost_gendev); pm_runtime_disable(&shost->shost_gendev); pm_runtime_set_suspended(&shost->shost_gendev); pm_runtime_put_noidle(&shost->shost_gendev); - scsi_destroy_command_freelist(shost); - out_destroy_tags: if (shost_use_blk_mq(shost)) scsi_mq_destroy_tags(shost); fail: @@ -359,7 +344,6 @@ static void scsi_host_dev_release(struct device *dev) kfree(dev_name(&shost->shost_dev)); } - scsi_destroy_command_freelist(shost); if (shost_use_blk_mq(shost)) { if (shost->tag_set.tags) scsi_mq_destroy_tags(shost); diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 2e24f31622f8..3d8d2153b448 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -98,163 +98,6 @@ EXPORT_SYMBOL(scsi_sd_probe_domain); ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain); EXPORT_SYMBOL(scsi_sd_pm_domain); -struct scsi_host_cmd_pool { - struct kmem_cache *cmd_slab; - unsigned int users; - char *cmd_name; -}; - -static struct scsi_host_cmd_pool scsi_cmd_pool = { - .cmd_name = "scsi_cmd_cache", -}; - -static DEFINE_MUTEX(host_cmd_pool_mutex); - -/** - * scsi_host_free_command - internal function to release a command - * @shost: host to free the command for - * @cmd: command to release - * - * the command must previously have been allocated by - * scsi_host_alloc_command. - */ -static void -scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) -{ - struct scsi_host_cmd_pool *pool = shost->cmd_pool; - - if (cmd->prot_sdb) - kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); - scsi_free_sense_buffer(shost, cmd->sense_buffer); - kmem_cache_free(pool->cmd_slab, cmd); -} - -/** - * scsi_host_alloc_command - internal function to allocate command - * @shost: SCSI host whose pool to allocate from - * @gfp_mask: mask for the allocation - * - * Returns a fully allocated command with sense buffer and protection - * data buffer (where applicable) or NULL on failure - */ -static struct scsi_cmnd * -scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask) -{ - struct scsi_host_cmd_pool *pool = shost->cmd_pool; - struct scsi_cmnd *cmd; - - cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask); - if (!cmd) - goto fail; - - cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp_mask, - NUMA_NO_NODE); - if (!cmd->sense_buffer) - goto fail_free_cmd; - - if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { - cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask); - if (!cmd->prot_sdb) - goto fail_free_sense; - } - - return cmd; - -fail_free_sense: - scsi_free_sense_buffer(shost, cmd->sense_buffer); -fail_free_cmd: - kmem_cache_free(pool->cmd_slab, cmd); -fail: - return NULL; -} - -/** - * __scsi_get_command - Allocate a struct scsi_cmnd - * @shost: host to transmit command - * @gfp_mask: allocation mask - * - * Description: allocate a struct scsi_cmd from host's slab, recycling from the - * host's free_list if necessary. - */ -static struct scsi_cmnd * -__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) -{ - struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask); - - if (unlikely(!cmd)) { - unsigned long flags; - - spin_lock_irqsave(&shost->free_list_lock, flags); - if (likely(!list_empty(&shost->free_list))) { - cmd = list_entry(shost->free_list.next, - struct scsi_cmnd, list); - list_del_init(&cmd->list); - } - spin_unlock_irqrestore(&shost->free_list_lock, flags); - - if (cmd) { - void *buf, *prot; - - buf = cmd->sense_buffer; - prot = cmd->prot_sdb; - - memset(cmd, 0, sizeof(*cmd)); - - cmd->sense_buffer = buf; - cmd->prot_sdb = prot; - } - } - - return cmd; -} - -/** - * scsi_get_command - Allocate and setup a scsi command block - * @dev: parent scsi device - * @gfp_mask: allocator flags - * - * Returns: The allocated scsi command structure. - */ -struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) -{ - struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask); - unsigned long flags; - - if (unlikely(cmd == NULL)) - return NULL; - - cmd->device = dev; - INIT_LIST_HEAD(&cmd->list); - INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); - spin_lock_irqsave(&dev->list_lock, flags); - list_add_tail(&cmd->list, &dev->cmd_list); - spin_unlock_irqrestore(&dev->list_lock, flags); - cmd->jiffies_at_alloc = jiffies; - return cmd; -} - -/** - * __scsi_put_command - Free a struct scsi_cmnd - * @shost: dev->host - * @cmd: Command to free - */ -static void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) -{ - unsigned long flags; - - if (unlikely(list_empty(&shost->free_list))) { - spin_lock_irqsave(&shost->free_list_lock, flags); - if (list_empty(&shost->free_list)) { - list_add(&cmd->list, &shost->free_list); - cmd = NULL; - } - spin_unlock_irqrestore(&shost->free_list_lock, flags); - } - - if (likely(cmd != NULL)) - scsi_host_free_command(shost, cmd); -} - /** * scsi_put_command - Free a scsi command block * @cmd: command block to free @@ -274,168 +117,6 @@ void scsi_put_command(struct scsi_cmnd *cmd) spin_unlock_irqrestore(&cmd->device->list_lock, flags); BUG_ON(delayed_work_pending(&cmd->abort_work)); - - __scsi_put_command(cmd->device->host, cmd); -} - -static struct scsi_host_cmd_pool * -scsi_find_host_cmd_pool(struct Scsi_Host *shost) -{ - if (shost->hostt->cmd_size) - return shost->hostt->cmd_pool; - return &scsi_cmd_pool; -} - -static void -scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool) -{ - kfree(pool->cmd_name); - kfree(pool); -} - -static struct scsi_host_cmd_pool * -scsi_alloc_host_cmd_pool(struct Scsi_Host *shost) -{ - struct scsi_host_template *hostt = shost->hostt; - struct scsi_host_cmd_pool *pool; - - pool = kzalloc(sizeof(*pool), GFP_KERNEL); - if (!pool) - return NULL; - - pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->proc_name); - if (!pool->cmd_name) { - scsi_free_host_cmd_pool(pool); - return NULL; - } - - if (hostt->cmd_size) - hostt->cmd_pool = pool; - - return pool; -} - -static struct scsi_host_cmd_pool * -scsi_get_host_cmd_pool(struct Scsi_Host *shost) -{ - struct scsi_host_template *hostt = shost->hostt; - struct scsi_host_cmd_pool *retval = NULL, *pool; - size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size; - - /* - * Select a command slab for this host and create it if not - * yet existent. - */ - mutex_lock(&host_cmd_pool_mutex); - pool = scsi_find_host_cmd_pool(shost); - if (!pool) { - pool = scsi_alloc_host_cmd_pool(shost); - if (!pool) - goto out; - } - - if (!pool->users) { - pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0, - SLAB_HWCACHE_ALIGN, NULL); - if (!pool->cmd_slab) - goto out_free_pool; - } - - pool->users++; - retval = pool; -out: - mutex_unlock(&host_cmd_pool_mutex); - return retval; - -out_free_pool: - if (hostt->cmd_size) { - scsi_free_host_cmd_pool(pool); - hostt->cmd_pool = NULL; - } - goto out; -} - -static void scsi_put_host_cmd_pool(struct Scsi_Host *shost) -{ - struct scsi_host_template *hostt = shost->hostt; - struct scsi_host_cmd_pool *pool; - - mutex_lock(&host_cmd_pool_mutex); - pool = scsi_find_host_cmd_pool(shost); - - /* - * This may happen if a driver has a mismatched get and put - * of the command pool; the driver should be implicated in - * the stack trace - */ - BUG_ON(pool->users == 0); - - if (!--pool->users) { - kmem_cache_destroy(pool->cmd_slab); - if (hostt->cmd_size) { - scsi_free_host_cmd_pool(pool); - hostt->cmd_pool = NULL; - } - } - mutex_unlock(&host_cmd_pool_mutex); -} - -/** - * scsi_setup_command_freelist - Setup the command freelist for a scsi host. - * @shost: host to allocate the freelist for. - * - * Description: The command freelist protects against system-wide out of memory - * deadlock by preallocating one SCSI command structure for each host, so the - * system can always write to a swap file on a device associated with that host. - * - * Returns: Nothing. - */ -int scsi_setup_command_freelist(struct Scsi_Host *shost) -{ - struct scsi_cmnd *cmd; - - spin_lock_init(&shost->free_list_lock); - INIT_LIST_HEAD(&shost->free_list); - - shost->cmd_pool = scsi_get_host_cmd_pool(shost); - if (!shost->cmd_pool) - return -ENOMEM; - - /* - * Get one backup command for this host. - */ - cmd = scsi_host_alloc_command(shost, GFP_KERNEL); - if (!cmd) { - scsi_put_host_cmd_pool(shost); - shost->cmd_pool = NULL; - return -ENOMEM; - } - list_add(&cmd->list, &shost->free_list); - return 0; -} - -/** - * scsi_destroy_command_freelist - Release the command freelist for a scsi host. - * @shost: host whose freelist is going to be destroyed - */ -void scsi_destroy_command_freelist(struct Scsi_Host *shost) -{ - /* - * If cmd_pool is NULL the free list was not initialized, so - * do not attempt to release resources. - */ - if (!shost->cmd_pool) - return; - - while (!list_empty(&shost->free_list)) { - struct scsi_cmnd *cmd; - - cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); - list_del_init(&cmd->list); - scsi_host_free_command(shost, cmd); - } - shost->cmd_pool = NULL; - scsi_put_host_cmd_pool(shost); } #ifdef CONFIG_SCSI_LOGGING diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 996e134d79fa..7c084600827b 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -2331,7 +2331,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) { struct scsi_cmnd *scmd; struct Scsi_Host *shost = dev->host; - struct request req; + struct request *rq; unsigned long flags; int error = 0, rtn, val; @@ -2346,14 +2346,16 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) return -EIO; error = -EIO; - scmd = scsi_get_command(dev, GFP_KERNEL); - if (!scmd) + rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) + + shost->hostt->cmd_size, GFP_KERNEL); + if (!rq) goto out_put_autopm_host; + blk_rq_init(NULL, rq); - blk_rq_init(NULL, &req); - scmd->request = &req; - - scmd->cmnd = req.cmd; + scmd = (struct scsi_cmnd *)(rq + 1); + scsi_init_command(dev, scmd); + scmd->request = rq; + scmd->cmnd = rq->cmd; scmd->scsi_done = scsi_reset_provider_done_command; memset(&scmd->sdb, 0, sizeof(scmd->sdb)); @@ -2413,6 +2415,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) scsi_run_host_queues(shost); scsi_put_command(scmd); + kfree(rq); out_put_autopm_host: scsi_autopm_put_host(shost); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 79505169e740..81ff5ad23b83 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -37,8 +37,7 @@ #include "scsi_priv.h" #include "scsi_logging.h" - -struct kmem_cache *scsi_sdb_cache; +static struct kmem_cache *scsi_sdb_cache; static struct kmem_cache *scsi_sense_cache; static struct kmem_cache *scsi_sense_isadma_cache; static DEFINE_MUTEX(scsi_sense_cache_mutex); @@ -50,14 +49,14 @@ scsi_select_sense_cache(struct Scsi_Host *shost) scsi_sense_isadma_cache : scsi_sense_cache; } -void scsi_free_sense_buffer(struct Scsi_Host *shost, +static void scsi_free_sense_buffer(struct Scsi_Host *shost, unsigned char *sense_buffer) { kmem_cache_free(scsi_select_sense_cache(shost), sense_buffer); } -unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost, gfp_t gfp_mask, - int numa_node) +static unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost, + gfp_t gfp_mask, int numa_node) { return kmem_cache_alloc_node(scsi_select_sense_cache(shost), gfp_mask, numa_node); @@ -697,14 +696,13 @@ static bool scsi_end_request(struct request *req, int error, if (bidi_bytes) scsi_release_bidi_buffers(cmd); + scsi_release_buffers(cmd); + scsi_put_command(cmd); spin_lock_irqsave(q->queue_lock, flags); blk_finish_request(req, error); spin_unlock_irqrestore(q->queue_lock, flags); - scsi_release_buffers(cmd); - - scsi_put_command(cmd); scsi_run_queue(q); } @@ -1161,34 +1159,22 @@ err_exit: } EXPORT_SYMBOL(scsi_init_io); -static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, - struct request *req) +void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) { - struct scsi_cmnd *cmd; - - if (!req->special) { - /* Bail if we can't get a reference to the device */ - if (!get_device(&sdev->sdev_gendev)) - return NULL; - - cmd = scsi_get_command(sdev, GFP_ATOMIC); - if (unlikely(!cmd)) { - put_device(&sdev->sdev_gendev); - return NULL; - } - req->special = cmd; - } else { - cmd = req->special; - } - - /* pull a tag out of the request if we have one */ - cmd->tag = req->tag; - cmd->request = req; + void *buf = cmd->sense_buffer; + void *prot = cmd->prot_sdb; + unsigned long flags; - cmd->cmnd = req->cmd; - cmd->prot_op = SCSI_PROT_NORMAL; + memset(cmd, 0, sizeof(*cmd)); + cmd->device = dev; + cmd->sense_buffer = buf; + cmd->prot_sdb = prot; + INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); + cmd->jiffies_at_alloc = jiffies; - return cmd; + spin_lock_irqsave(&dev->list_lock, flags); + list_add_tail(&cmd->list, &dev->cmd_list); + spin_unlock_irqrestore(&dev->list_lock, flags); } static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) @@ -1349,19 +1335,29 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret) static int scsi_prep_fn(struct request_queue *q, struct request *req) { struct scsi_device *sdev = q->queuedata; - struct scsi_cmnd *cmd; + struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); int ret; ret = scsi_prep_state_check(sdev, req); if (ret != BLKPREP_OK) goto out; - cmd = scsi_get_cmd_from_req(sdev, req); - if (unlikely(!cmd)) { - ret = BLKPREP_DEFER; - goto out; + if (!req->special) { + /* Bail if we can't get a reference to the device */ + if (unlikely(!get_device(&sdev->sdev_gendev))) { + ret = BLKPREP_DEFER; + goto out; + } + + scsi_init_command(sdev, cmd); + req->special = cmd; } + cmd->tag = req->tag; + cmd->request = req; + cmd->cmnd = req->cmd; + cmd->prot_op = SCSI_PROT_NORMAL; + ret = scsi_setup_cmnd(sdev, req); out: return scsi_prep_return(q, req, ret); @@ -2119,15 +2115,61 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) } EXPORT_SYMBOL_GPL(__scsi_init_queue); +static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp) +{ + struct Scsi_Host *shost = q->rq_alloc_data; + struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); + + memset(cmd, 0, sizeof(*cmd)); + + cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp, NUMA_NO_NODE); + if (!cmd->sense_buffer) + goto fail; + + if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { + cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp); + if (!cmd->prot_sdb) + goto fail_free_sense; + } + + return 0; + +fail_free_sense: + scsi_free_sense_buffer(shost, cmd->sense_buffer); +fail: + return -ENOMEM; +} + +static void scsi_exit_rq(struct request_queue *q, struct request *rq) +{ + struct Scsi_Host *shost = q->rq_alloc_data; + struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); + + if (cmd->prot_sdb) + kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); + scsi_free_sense_buffer(shost, cmd->sense_buffer); +} + struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) { + struct Scsi_Host *shost = sdev->host; struct request_queue *q; - q = blk_init_queue(scsi_request_fn, NULL); + q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE); if (!q) return NULL; + q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; + q->rq_alloc_data = shost; + q->request_fn = scsi_request_fn; + q->init_rq_fn = scsi_init_rq; + q->exit_rq_fn = scsi_exit_rq; + + if (blk_init_allocated_queue(q) < 0) { + blk_cleanup_queue(q); + return NULL; + } - __scsi_init_queue(sdev->host, q); + __scsi_init_queue(shost, q); blk_queue_prep_rq(q, scsi_prep_fn); blk_queue_unprep_rq(q, scsi_unprep_fn); blk_queue_softirq_done(q, scsi_softirq_done); diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 1a712c631a8b..99bfc985e190 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -30,13 +30,8 @@ extern void scsi_exit_hosts(void); /* scsi.c */ extern bool scsi_use_blk_mq; -void scsi_free_sense_buffer(struct Scsi_Host *shost, - unsigned char *sense_buffer); -unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost, gfp_t gfp_mask, - int numa_node); int scsi_init_sense_cache(struct Scsi_Host *shost); -extern int scsi_setup_command_freelist(struct Scsi_Host *shost); -extern void scsi_destroy_command_freelist(struct Scsi_Host *shost); +void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd); #ifdef CONFIG_SCSI_LOGGING void scsi_log_send(struct scsi_cmnd *cmd); void scsi_log_completion(struct scsi_cmnd *cmd, int disposition); @@ -101,7 +96,6 @@ extern void scsi_exit_queue(void); extern void scsi_evt_thread(struct work_struct *work); struct request_queue; struct request; -extern struct kmem_cache *scsi_sdb_cache; /* scsi_proc.c */ #ifdef CONFIG_SCSI_PROC_FS diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index f4964d7db313..3cd8c3bec638 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -551,9 +551,6 @@ struct Scsi_Host { struct list_head __devices; struct list_head __targets; - struct scsi_host_cmd_pool *cmd_pool; - spinlock_t free_list_lock; - struct list_head free_list; /* backup store of cmd structs */ struct list_head starved_list; spinlock_t default_lock; -- 2.20.1