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2050 lines
50 KiB
2050 lines
50 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Add configfs and memory store: Kyungchan Koh <[email protected]> and |
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* Shaohua Li <[email protected]> |
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*/ |
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#include <linux/module.h> |
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|
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#include <linux/moduleparam.h> |
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#include <linux/sched.h> |
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#include <linux/fs.h> |
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#include <linux/init.h> |
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#include "null_blk.h" |
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#define FREE_BATCH 16 |
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|
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#define TICKS_PER_SEC 50ULL |
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#define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC) |
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#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
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static DECLARE_FAULT_ATTR(null_timeout_attr); |
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static DECLARE_FAULT_ATTR(null_requeue_attr); |
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static DECLARE_FAULT_ATTR(null_init_hctx_attr); |
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#endif |
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static inline u64 mb_per_tick(int mbps) |
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{ |
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return (1 << 20) / TICKS_PER_SEC * ((u64) mbps); |
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} |
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|
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/* |
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* Status flags for nullb_device. |
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* |
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* CONFIGURED: Device has been configured and turned on. Cannot reconfigure. |
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* UP: Device is currently on and visible in userspace. |
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* THROTTLED: Device is being throttled. |
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* CACHE: Device is using a write-back cache. |
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*/ |
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enum nullb_device_flags { |
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NULLB_DEV_FL_CONFIGURED = 0, |
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NULLB_DEV_FL_UP = 1, |
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NULLB_DEV_FL_THROTTLED = 2, |
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NULLB_DEV_FL_CACHE = 3, |
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}; |
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#define MAP_SZ ((PAGE_SIZE >> SECTOR_SHIFT) + 2) |
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/* |
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* nullb_page is a page in memory for nullb devices. |
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* |
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* @page: The page holding the data. |
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* @bitmap: The bitmap represents which sector in the page has data. |
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* Each bit represents one block size. For example, sector 8 |
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* will use the 7th bit |
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* The highest 2 bits of bitmap are for special purpose. LOCK means the cache |
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* page is being flushing to storage. FREE means the cache page is freed and |
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* should be skipped from flushing to storage. Please see |
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* null_make_cache_space |
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*/ |
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struct nullb_page { |
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struct page *page; |
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DECLARE_BITMAP(bitmap, MAP_SZ); |
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}; |
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#define NULLB_PAGE_LOCK (MAP_SZ - 1) |
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#define NULLB_PAGE_FREE (MAP_SZ - 2) |
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|
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static LIST_HEAD(nullb_list); |
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static struct mutex lock; |
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static int null_major; |
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static DEFINE_IDA(nullb_indexes); |
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static struct blk_mq_tag_set tag_set; |
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enum { |
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NULL_IRQ_NONE = 0, |
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NULL_IRQ_SOFTIRQ = 1, |
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NULL_IRQ_TIMER = 2, |
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}; |
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enum { |
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NULL_Q_BIO = 0, |
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NULL_Q_RQ = 1, |
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NULL_Q_MQ = 2, |
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}; |
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static bool g_virt_boundary = false; |
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module_param_named(virt_boundary, g_virt_boundary, bool, 0444); |
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MODULE_PARM_DESC(virt_boundary, "Require a virtual boundary for the device. Default: False"); |
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|
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static int g_no_sched; |
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module_param_named(no_sched, g_no_sched, int, 0444); |
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MODULE_PARM_DESC(no_sched, "No io scheduler"); |
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|
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static int g_submit_queues = 1; |
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module_param_named(submit_queues, g_submit_queues, int, 0444); |
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MODULE_PARM_DESC(submit_queues, "Number of submission queues"); |
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static int g_home_node = NUMA_NO_NODE; |
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module_param_named(home_node, g_home_node, int, 0444); |
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MODULE_PARM_DESC(home_node, "Home node for the device"); |
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|
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#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
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/* |
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* For more details about fault injection, please refer to |
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* Documentation/fault-injection/fault-injection.rst. |
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*/ |
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static char g_timeout_str[80]; |
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module_param_string(timeout, g_timeout_str, sizeof(g_timeout_str), 0444); |
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MODULE_PARM_DESC(timeout, "Fault injection. timeout=<interval>,<probability>,<space>,<times>"); |
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|
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static char g_requeue_str[80]; |
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module_param_string(requeue, g_requeue_str, sizeof(g_requeue_str), 0444); |
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MODULE_PARM_DESC(requeue, "Fault injection. requeue=<interval>,<probability>,<space>,<times>"); |
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|
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static char g_init_hctx_str[80]; |
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module_param_string(init_hctx, g_init_hctx_str, sizeof(g_init_hctx_str), 0444); |
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MODULE_PARM_DESC(init_hctx, "Fault injection to fail hctx init. init_hctx=<interval>,<probability>,<space>,<times>"); |
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#endif |
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static int g_queue_mode = NULL_Q_MQ; |
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|
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static int null_param_store_val(const char *str, int *val, int min, int max) |
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{ |
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int ret, new_val; |
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ret = kstrtoint(str, 10, &new_val); |
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if (ret) |
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return -EINVAL; |
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if (new_val < min || new_val > max) |
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return -EINVAL; |
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*val = new_val; |
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return 0; |
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} |
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static int null_set_queue_mode(const char *str, const struct kernel_param *kp) |
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{ |
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return null_param_store_val(str, &g_queue_mode, NULL_Q_BIO, NULL_Q_MQ); |
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} |
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static const struct kernel_param_ops null_queue_mode_param_ops = { |
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.set = null_set_queue_mode, |
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.get = param_get_int, |
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}; |
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device_param_cb(queue_mode, &null_queue_mode_param_ops, &g_queue_mode, 0444); |
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MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)"); |
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|
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static int g_gb = 250; |
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module_param_named(gb, g_gb, int, 0444); |
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MODULE_PARM_DESC(gb, "Size in GB"); |
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|
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static int g_bs = 512; |
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module_param_named(bs, g_bs, int, 0444); |
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MODULE_PARM_DESC(bs, "Block size (in bytes)"); |
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|
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static int g_max_sectors; |
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module_param_named(max_sectors, g_max_sectors, int, 0444); |
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MODULE_PARM_DESC(max_sectors, "Maximum size of a command (in 512B sectors)"); |
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|
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static unsigned int nr_devices = 1; |
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module_param(nr_devices, uint, 0444); |
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MODULE_PARM_DESC(nr_devices, "Number of devices to register"); |
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|
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static bool g_blocking; |
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module_param_named(blocking, g_blocking, bool, 0444); |
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MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device"); |
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static bool shared_tags; |
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module_param(shared_tags, bool, 0444); |
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MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq"); |
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static bool g_shared_tag_bitmap; |
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module_param_named(shared_tag_bitmap, g_shared_tag_bitmap, bool, 0444); |
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MODULE_PARM_DESC(shared_tag_bitmap, "Use shared tag bitmap for all submission queues for blk-mq"); |
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static int g_irqmode = NULL_IRQ_SOFTIRQ; |
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static int null_set_irqmode(const char *str, const struct kernel_param *kp) |
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{ |
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return null_param_store_val(str, &g_irqmode, NULL_IRQ_NONE, |
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NULL_IRQ_TIMER); |
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} |
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static const struct kernel_param_ops null_irqmode_param_ops = { |
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.set = null_set_irqmode, |
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.get = param_get_int, |
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}; |
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|
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device_param_cb(irqmode, &null_irqmode_param_ops, &g_irqmode, 0444); |
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MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); |
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|
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static unsigned long g_completion_nsec = 10000; |
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module_param_named(completion_nsec, g_completion_nsec, ulong, 0444); |
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MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); |
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static int g_hw_queue_depth = 64; |
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module_param_named(hw_queue_depth, g_hw_queue_depth, int, 0444); |
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MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); |
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|
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static bool g_use_per_node_hctx; |
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module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444); |
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MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); |
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|
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static bool g_zoned; |
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module_param_named(zoned, g_zoned, bool, S_IRUGO); |
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MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false"); |
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|
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static unsigned long g_zone_size = 256; |
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module_param_named(zone_size, g_zone_size, ulong, S_IRUGO); |
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MODULE_PARM_DESC(zone_size, "Zone size in MB when block device is zoned. Must be power-of-two: Default: 256"); |
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|
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static unsigned long g_zone_capacity; |
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module_param_named(zone_capacity, g_zone_capacity, ulong, 0444); |
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MODULE_PARM_DESC(zone_capacity, "Zone capacity in MB when block device is zoned. Can be less than or equal to zone size. Default: Zone size"); |
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|
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static unsigned int g_zone_nr_conv; |
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module_param_named(zone_nr_conv, g_zone_nr_conv, uint, 0444); |
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MODULE_PARM_DESC(zone_nr_conv, "Number of conventional zones when block device is zoned. Default: 0"); |
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static unsigned int g_zone_max_open; |
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module_param_named(zone_max_open, g_zone_max_open, uint, 0444); |
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MODULE_PARM_DESC(zone_max_open, "Maximum number of open zones when block device is zoned. Default: 0 (no limit)"); |
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static unsigned int g_zone_max_active; |
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module_param_named(zone_max_active, g_zone_max_active, uint, 0444); |
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MODULE_PARM_DESC(zone_max_active, "Maximum number of active zones when block device is zoned. Default: 0 (no limit)"); |
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static struct nullb_device *null_alloc_dev(void); |
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static void null_free_dev(struct nullb_device *dev); |
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static void null_del_dev(struct nullb *nullb); |
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static int null_add_dev(struct nullb_device *dev); |
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static void null_free_device_storage(struct nullb_device *dev, bool is_cache); |
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static inline struct nullb_device *to_nullb_device(struct config_item *item) |
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{ |
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return item ? container_of(item, struct nullb_device, item) : NULL; |
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} |
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static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page) |
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{ |
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return snprintf(page, PAGE_SIZE, "%u\n", val); |
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} |
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static inline ssize_t nullb_device_ulong_attr_show(unsigned long val, |
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char *page) |
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{ |
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return snprintf(page, PAGE_SIZE, "%lu\n", val); |
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} |
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static inline ssize_t nullb_device_bool_attr_show(bool val, char *page) |
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{ |
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return snprintf(page, PAGE_SIZE, "%u\n", val); |
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} |
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static ssize_t nullb_device_uint_attr_store(unsigned int *val, |
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const char *page, size_t count) |
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{ |
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unsigned int tmp; |
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int result; |
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result = kstrtouint(page, 0, &tmp); |
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if (result < 0) |
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return result; |
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*val = tmp; |
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return count; |
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} |
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static ssize_t nullb_device_ulong_attr_store(unsigned long *val, |
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const char *page, size_t count) |
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{ |
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int result; |
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unsigned long tmp; |
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result = kstrtoul(page, 0, &tmp); |
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if (result < 0) |
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return result; |
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*val = tmp; |
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return count; |
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} |
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static ssize_t nullb_device_bool_attr_store(bool *val, const char *page, |
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size_t count) |
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{ |
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bool tmp; |
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int result; |
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result = kstrtobool(page, &tmp); |
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if (result < 0) |
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return result; |
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*val = tmp; |
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return count; |
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} |
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|
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/* The following macro should only be used with TYPE = {uint, ulong, bool}. */ |
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#define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY) \ |
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static ssize_t \ |
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nullb_device_##NAME##_show(struct config_item *item, char *page) \ |
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{ \ |
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return nullb_device_##TYPE##_attr_show( \ |
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to_nullb_device(item)->NAME, page); \ |
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} \ |
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static ssize_t \ |
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nullb_device_##NAME##_store(struct config_item *item, const char *page, \ |
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size_t count) \ |
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{ \ |
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int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;\ |
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struct nullb_device *dev = to_nullb_device(item); \ |
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TYPE new_value = 0; \ |
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int ret; \ |
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\ |
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ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);\ |
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if (ret < 0) \ |
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return ret; \ |
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if (apply_fn) \ |
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ret = apply_fn(dev, new_value); \ |
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else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) \ |
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ret = -EBUSY; \ |
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if (ret < 0) \ |
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return ret; \ |
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dev->NAME = new_value; \ |
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return count; \ |
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} \ |
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CONFIGFS_ATTR(nullb_device_, NAME); |
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|
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static int nullb_apply_submit_queues(struct nullb_device *dev, |
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unsigned int submit_queues) |
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{ |
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struct nullb *nullb = dev->nullb; |
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struct blk_mq_tag_set *set; |
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|
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if (!nullb) |
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return 0; |
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/* |
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* Make sure that null_init_hctx() does not access nullb->queues[] past |
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* the end of that array. |
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*/ |
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if (submit_queues > nr_cpu_ids) |
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return -EINVAL; |
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set = nullb->tag_set; |
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blk_mq_update_nr_hw_queues(set, submit_queues); |
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return set->nr_hw_queues == submit_queues ? 0 : -ENOMEM; |
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} |
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NULLB_DEVICE_ATTR(size, ulong, NULL); |
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NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL); |
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NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues); |
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NULLB_DEVICE_ATTR(home_node, uint, NULL); |
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NULLB_DEVICE_ATTR(queue_mode, uint, NULL); |
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NULLB_DEVICE_ATTR(blocksize, uint, NULL); |
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NULLB_DEVICE_ATTR(max_sectors, uint, NULL); |
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NULLB_DEVICE_ATTR(irqmode, uint, NULL); |
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NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL); |
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NULLB_DEVICE_ATTR(index, uint, NULL); |
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NULLB_DEVICE_ATTR(blocking, bool, NULL); |
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NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL); |
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NULLB_DEVICE_ATTR(memory_backed, bool, NULL); |
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NULLB_DEVICE_ATTR(discard, bool, NULL); |
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NULLB_DEVICE_ATTR(mbps, uint, NULL); |
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NULLB_DEVICE_ATTR(cache_size, ulong, NULL); |
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NULLB_DEVICE_ATTR(zoned, bool, NULL); |
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NULLB_DEVICE_ATTR(zone_size, ulong, NULL); |
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NULLB_DEVICE_ATTR(zone_capacity, ulong, NULL); |
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NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL); |
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NULLB_DEVICE_ATTR(zone_max_open, uint, NULL); |
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NULLB_DEVICE_ATTR(zone_max_active, uint, NULL); |
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NULLB_DEVICE_ATTR(virt_boundary, bool, NULL); |
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|
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static ssize_t nullb_device_power_show(struct config_item *item, char *page) |
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{ |
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return nullb_device_bool_attr_show(to_nullb_device(item)->power, page); |
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} |
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|
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static ssize_t nullb_device_power_store(struct config_item *item, |
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const char *page, size_t count) |
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{ |
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struct nullb_device *dev = to_nullb_device(item); |
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bool newp = false; |
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ssize_t ret; |
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|
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ret = nullb_device_bool_attr_store(&newp, page, count); |
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if (ret < 0) |
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return ret; |
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|
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if (!dev->power && newp) { |
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if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags)) |
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return count; |
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if (null_add_dev(dev)) { |
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clear_bit(NULLB_DEV_FL_UP, &dev->flags); |
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return -ENOMEM; |
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} |
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|
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set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); |
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dev->power = newp; |
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} else if (dev->power && !newp) { |
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if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { |
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mutex_lock(&lock); |
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dev->power = newp; |
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null_del_dev(dev->nullb); |
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mutex_unlock(&lock); |
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} |
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clear_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); |
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} |
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|
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return count; |
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} |
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|
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CONFIGFS_ATTR(nullb_device_, power); |
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|
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static ssize_t nullb_device_badblocks_show(struct config_item *item, char *page) |
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{ |
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struct nullb_device *t_dev = to_nullb_device(item); |
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|
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return badblocks_show(&t_dev->badblocks, page, 0); |
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} |
|
|
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static ssize_t nullb_device_badblocks_store(struct config_item *item, |
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const char *page, size_t count) |
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{ |
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struct nullb_device *t_dev = to_nullb_device(item); |
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char *orig, *buf, *tmp; |
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u64 start, end; |
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int ret; |
|
|
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orig = kstrndup(page, count, GFP_KERNEL); |
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if (!orig) |
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return -ENOMEM; |
|
|
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buf = strstrip(orig); |
|
|
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ret = -EINVAL; |
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if (buf[0] != '+' && buf[0] != '-') |
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goto out; |
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tmp = strchr(&buf[1], '-'); |
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if (!tmp) |
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goto out; |
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*tmp = '\0'; |
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ret = kstrtoull(buf + 1, 0, &start); |
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if (ret) |
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goto out; |
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ret = kstrtoull(tmp + 1, 0, &end); |
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if (ret) |
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goto out; |
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ret = -EINVAL; |
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if (start > end) |
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goto out; |
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/* enable badblocks */ |
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cmpxchg(&t_dev->badblocks.shift, -1, 0); |
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if (buf[0] == '+') |
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ret = badblocks_set(&t_dev->badblocks, start, |
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end - start + 1, 1); |
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else |
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ret = badblocks_clear(&t_dev->badblocks, start, |
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end - start + 1); |
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if (ret == 0) |
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ret = count; |
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out: |
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kfree(orig); |
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return ret; |
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} |
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CONFIGFS_ATTR(nullb_device_, badblocks); |
|
|
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static struct configfs_attribute *nullb_device_attrs[] = { |
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&nullb_device_attr_size, |
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&nullb_device_attr_completion_nsec, |
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&nullb_device_attr_submit_queues, |
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&nullb_device_attr_home_node, |
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&nullb_device_attr_queue_mode, |
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&nullb_device_attr_blocksize, |
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&nullb_device_attr_max_sectors, |
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&nullb_device_attr_irqmode, |
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&nullb_device_attr_hw_queue_depth, |
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&nullb_device_attr_index, |
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&nullb_device_attr_blocking, |
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&nullb_device_attr_use_per_node_hctx, |
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&nullb_device_attr_power, |
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&nullb_device_attr_memory_backed, |
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&nullb_device_attr_discard, |
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&nullb_device_attr_mbps, |
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&nullb_device_attr_cache_size, |
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&nullb_device_attr_badblocks, |
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&nullb_device_attr_zoned, |
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&nullb_device_attr_zone_size, |
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&nullb_device_attr_zone_capacity, |
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&nullb_device_attr_zone_nr_conv, |
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&nullb_device_attr_zone_max_open, |
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&nullb_device_attr_zone_max_active, |
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&nullb_device_attr_virt_boundary, |
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NULL, |
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}; |
|
|
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static void nullb_device_release(struct config_item *item) |
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{ |
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struct nullb_device *dev = to_nullb_device(item); |
|
|
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null_free_device_storage(dev, false); |
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null_free_dev(dev); |
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} |
|
|
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static struct configfs_item_operations nullb_device_ops = { |
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.release = nullb_device_release, |
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}; |
|
|
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static const struct config_item_type nullb_device_type = { |
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.ct_item_ops = &nullb_device_ops, |
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.ct_attrs = nullb_device_attrs, |
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.ct_owner = THIS_MODULE, |
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}; |
|
|
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static struct |
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config_item *nullb_group_make_item(struct config_group *group, const char *name) |
|
{ |
|
struct nullb_device *dev; |
|
|
|
dev = null_alloc_dev(); |
|
if (!dev) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
config_item_init_type_name(&dev->item, name, &nullb_device_type); |
|
|
|
return &dev->item; |
|
} |
|
|
|
static void |
|
nullb_group_drop_item(struct config_group *group, struct config_item *item) |
|
{ |
|
struct nullb_device *dev = to_nullb_device(item); |
|
|
|
if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { |
|
mutex_lock(&lock); |
|
dev->power = false; |
|
null_del_dev(dev->nullb); |
|
mutex_unlock(&lock); |
|
} |
|
|
|
config_item_put(item); |
|
} |
|
|
|
static ssize_t memb_group_features_show(struct config_item *item, char *page) |
|
{ |
|
return snprintf(page, PAGE_SIZE, |
|
"memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size,zone_capacity,zone_nr_conv,zone_max_open,zone_max_active,blocksize,max_sectors,virt_boundary\n"); |
|
} |
|
|
|
CONFIGFS_ATTR_RO(memb_group_, features); |
|
|
|
static struct configfs_attribute *nullb_group_attrs[] = { |
|
&memb_group_attr_features, |
|
NULL, |
|
}; |
|
|
|
static struct configfs_group_operations nullb_group_ops = { |
|
.make_item = nullb_group_make_item, |
|
.drop_item = nullb_group_drop_item, |
|
}; |
|
|
|
static const struct config_item_type nullb_group_type = { |
|
.ct_group_ops = &nullb_group_ops, |
|
.ct_attrs = nullb_group_attrs, |
|
.ct_owner = THIS_MODULE, |
|
}; |
|
|
|
static struct configfs_subsystem nullb_subsys = { |
|
.su_group = { |
|
.cg_item = { |
|
.ci_namebuf = "nullb", |
|
.ci_type = &nullb_group_type, |
|
}, |
|
}, |
|
}; |
|
|
|
static inline int null_cache_active(struct nullb *nullb) |
|
{ |
|
return test_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); |
|
} |
|
|
|
static struct nullb_device *null_alloc_dev(void) |
|
{ |
|
struct nullb_device *dev; |
|
|
|
dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
|
if (!dev) |
|
return NULL; |
|
INIT_RADIX_TREE(&dev->data, GFP_ATOMIC); |
|
INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC); |
|
if (badblocks_init(&dev->badblocks, 0)) { |
|
kfree(dev); |
|
return NULL; |
|
} |
|
|
|
dev->size = g_gb * 1024; |
|
dev->completion_nsec = g_completion_nsec; |
|
dev->submit_queues = g_submit_queues; |
|
dev->home_node = g_home_node; |
|
dev->queue_mode = g_queue_mode; |
|
dev->blocksize = g_bs; |
|
dev->max_sectors = g_max_sectors; |
|
dev->irqmode = g_irqmode; |
|
dev->hw_queue_depth = g_hw_queue_depth; |
|
dev->blocking = g_blocking; |
|
dev->use_per_node_hctx = g_use_per_node_hctx; |
|
dev->zoned = g_zoned; |
|
dev->zone_size = g_zone_size; |
|
dev->zone_capacity = g_zone_capacity; |
|
dev->zone_nr_conv = g_zone_nr_conv; |
|
dev->zone_max_open = g_zone_max_open; |
|
dev->zone_max_active = g_zone_max_active; |
|
dev->virt_boundary = g_virt_boundary; |
|
return dev; |
|
} |
|
|
|
static void null_free_dev(struct nullb_device *dev) |
|
{ |
|
if (!dev) |
|
return; |
|
|
|
null_free_zoned_dev(dev); |
|
badblocks_exit(&dev->badblocks); |
|
kfree(dev); |
|
} |
|
|
|
static void put_tag(struct nullb_queue *nq, unsigned int tag) |
|
{ |
|
clear_bit_unlock(tag, nq->tag_map); |
|
|
|
if (waitqueue_active(&nq->wait)) |
|
wake_up(&nq->wait); |
|
} |
|
|
|
static unsigned int get_tag(struct nullb_queue *nq) |
|
{ |
|
unsigned int tag; |
|
|
|
do { |
|
tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); |
|
if (tag >= nq->queue_depth) |
|
return -1U; |
|
} while (test_and_set_bit_lock(tag, nq->tag_map)); |
|
|
|
return tag; |
|
} |
|
|
|
static void free_cmd(struct nullb_cmd *cmd) |
|
{ |
|
put_tag(cmd->nq, cmd->tag); |
|
} |
|
|
|
static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer); |
|
|
|
static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) |
|
{ |
|
struct nullb_cmd *cmd; |
|
unsigned int tag; |
|
|
|
tag = get_tag(nq); |
|
if (tag != -1U) { |
|
cmd = &nq->cmds[tag]; |
|
cmd->tag = tag; |
|
cmd->error = BLK_STS_OK; |
|
cmd->nq = nq; |
|
if (nq->dev->irqmode == NULL_IRQ_TIMER) { |
|
hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, |
|
HRTIMER_MODE_REL); |
|
cmd->timer.function = null_cmd_timer_expired; |
|
} |
|
return cmd; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait) |
|
{ |
|
struct nullb_cmd *cmd; |
|
DEFINE_WAIT(wait); |
|
|
|
cmd = __alloc_cmd(nq); |
|
if (cmd || !can_wait) |
|
return cmd; |
|
|
|
do { |
|
prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); |
|
cmd = __alloc_cmd(nq); |
|
if (cmd) |
|
break; |
|
|
|
io_schedule(); |
|
} while (1); |
|
|
|
finish_wait(&nq->wait, &wait); |
|
return cmd; |
|
} |
|
|
|
static void end_cmd(struct nullb_cmd *cmd) |
|
{ |
|
int queue_mode = cmd->nq->dev->queue_mode; |
|
|
|
switch (queue_mode) { |
|
case NULL_Q_MQ: |
|
blk_mq_end_request(cmd->rq, cmd->error); |
|
return; |
|
case NULL_Q_BIO: |
|
cmd->bio->bi_status = cmd->error; |
|
bio_endio(cmd->bio); |
|
break; |
|
} |
|
|
|
free_cmd(cmd); |
|
} |
|
|
|
static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) |
|
{ |
|
end_cmd(container_of(timer, struct nullb_cmd, timer)); |
|
|
|
return HRTIMER_NORESTART; |
|
} |
|
|
|
static void null_cmd_end_timer(struct nullb_cmd *cmd) |
|
{ |
|
ktime_t kt = cmd->nq->dev->completion_nsec; |
|
|
|
hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL); |
|
} |
|
|
|
static void null_complete_rq(struct request *rq) |
|
{ |
|
end_cmd(blk_mq_rq_to_pdu(rq)); |
|
} |
|
|
|
static struct nullb_page *null_alloc_page(gfp_t gfp_flags) |
|
{ |
|
struct nullb_page *t_page; |
|
|
|
t_page = kmalloc(sizeof(struct nullb_page), gfp_flags); |
|
if (!t_page) |
|
goto out; |
|
|
|
t_page->page = alloc_pages(gfp_flags, 0); |
|
if (!t_page->page) |
|
goto out_freepage; |
|
|
|
memset(t_page->bitmap, 0, sizeof(t_page->bitmap)); |
|
return t_page; |
|
out_freepage: |
|
kfree(t_page); |
|
out: |
|
return NULL; |
|
} |
|
|
|
static void null_free_page(struct nullb_page *t_page) |
|
{ |
|
__set_bit(NULLB_PAGE_FREE, t_page->bitmap); |
|
if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap)) |
|
return; |
|
__free_page(t_page->page); |
|
kfree(t_page); |
|
} |
|
|
|
static bool null_page_empty(struct nullb_page *page) |
|
{ |
|
int size = MAP_SZ - 2; |
|
|
|
return find_first_bit(page->bitmap, size) == size; |
|
} |
|
|
|
static void null_free_sector(struct nullb *nullb, sector_t sector, |
|
bool is_cache) |
|
{ |
|
unsigned int sector_bit; |
|
u64 idx; |
|
struct nullb_page *t_page, *ret; |
|
struct radix_tree_root *root; |
|
|
|
root = is_cache ? &nullb->dev->cache : &nullb->dev->data; |
|
idx = sector >> PAGE_SECTORS_SHIFT; |
|
sector_bit = (sector & SECTOR_MASK); |
|
|
|
t_page = radix_tree_lookup(root, idx); |
|
if (t_page) { |
|
__clear_bit(sector_bit, t_page->bitmap); |
|
|
|
if (null_page_empty(t_page)) { |
|
ret = radix_tree_delete_item(root, idx, t_page); |
|
WARN_ON(ret != t_page); |
|
null_free_page(ret); |
|
if (is_cache) |
|
nullb->dev->curr_cache -= PAGE_SIZE; |
|
} |
|
} |
|
} |
|
|
|
static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx, |
|
struct nullb_page *t_page, bool is_cache) |
|
{ |
|
struct radix_tree_root *root; |
|
|
|
root = is_cache ? &nullb->dev->cache : &nullb->dev->data; |
|
|
|
if (radix_tree_insert(root, idx, t_page)) { |
|
null_free_page(t_page); |
|
t_page = radix_tree_lookup(root, idx); |
|
WARN_ON(!t_page || t_page->page->index != idx); |
|
} else if (is_cache) |
|
nullb->dev->curr_cache += PAGE_SIZE; |
|
|
|
return t_page; |
|
} |
|
|
|
static void null_free_device_storage(struct nullb_device *dev, bool is_cache) |
|
{ |
|
unsigned long pos = 0; |
|
int nr_pages; |
|
struct nullb_page *ret, *t_pages[FREE_BATCH]; |
|
struct radix_tree_root *root; |
|
|
|
root = is_cache ? &dev->cache : &dev->data; |
|
|
|
do { |
|
int i; |
|
|
|
nr_pages = radix_tree_gang_lookup(root, |
|
(void **)t_pages, pos, FREE_BATCH); |
|
|
|
for (i = 0; i < nr_pages; i++) { |
|
pos = t_pages[i]->page->index; |
|
ret = radix_tree_delete_item(root, pos, t_pages[i]); |
|
WARN_ON(ret != t_pages[i]); |
|
null_free_page(ret); |
|
} |
|
|
|
pos++; |
|
} while (nr_pages == FREE_BATCH); |
|
|
|
if (is_cache) |
|
dev->curr_cache = 0; |
|
} |
|
|
|
static struct nullb_page *__null_lookup_page(struct nullb *nullb, |
|
sector_t sector, bool for_write, bool is_cache) |
|
{ |
|
unsigned int sector_bit; |
|
u64 idx; |
|
struct nullb_page *t_page; |
|
struct radix_tree_root *root; |
|
|
|
idx = sector >> PAGE_SECTORS_SHIFT; |
|
sector_bit = (sector & SECTOR_MASK); |
|
|
|
root = is_cache ? &nullb->dev->cache : &nullb->dev->data; |
|
t_page = radix_tree_lookup(root, idx); |
|
WARN_ON(t_page && t_page->page->index != idx); |
|
|
|
if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap))) |
|
return t_page; |
|
|
|
return NULL; |
|
} |
|
|
|
static struct nullb_page *null_lookup_page(struct nullb *nullb, |
|
sector_t sector, bool for_write, bool ignore_cache) |
|
{ |
|
struct nullb_page *page = NULL; |
|
|
|
if (!ignore_cache) |
|
page = __null_lookup_page(nullb, sector, for_write, true); |
|
if (page) |
|
return page; |
|
return __null_lookup_page(nullb, sector, for_write, false); |
|
} |
|
|
|
static struct nullb_page *null_insert_page(struct nullb *nullb, |
|
sector_t sector, bool ignore_cache) |
|
__releases(&nullb->lock) |
|
__acquires(&nullb->lock) |
|
{ |
|
u64 idx; |
|
struct nullb_page *t_page; |
|
|
|
t_page = null_lookup_page(nullb, sector, true, ignore_cache); |
|
if (t_page) |
|
return t_page; |
|
|
|
spin_unlock_irq(&nullb->lock); |
|
|
|
t_page = null_alloc_page(GFP_NOIO); |
|
if (!t_page) |
|
goto out_lock; |
|
|
|
if (radix_tree_preload(GFP_NOIO)) |
|
goto out_freepage; |
|
|
|
spin_lock_irq(&nullb->lock); |
|
idx = sector >> PAGE_SECTORS_SHIFT; |
|
t_page->page->index = idx; |
|
t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache); |
|
radix_tree_preload_end(); |
|
|
|
return t_page; |
|
out_freepage: |
|
null_free_page(t_page); |
|
out_lock: |
|
spin_lock_irq(&nullb->lock); |
|
return null_lookup_page(nullb, sector, true, ignore_cache); |
|
} |
|
|
|
static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page) |
|
{ |
|
int i; |
|
unsigned int offset; |
|
u64 idx; |
|
struct nullb_page *t_page, *ret; |
|
void *dst, *src; |
|
|
|
idx = c_page->page->index; |
|
|
|
t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true); |
|
|
|
__clear_bit(NULLB_PAGE_LOCK, c_page->bitmap); |
|
if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) { |
|
null_free_page(c_page); |
|
if (t_page && null_page_empty(t_page)) { |
|
ret = radix_tree_delete_item(&nullb->dev->data, |
|
idx, t_page); |
|
null_free_page(t_page); |
|
} |
|
return 0; |
|
} |
|
|
|
if (!t_page) |
|
return -ENOMEM; |
|
|
|
src = kmap_atomic(c_page->page); |
|
dst = kmap_atomic(t_page->page); |
|
|
|
for (i = 0; i < PAGE_SECTORS; |
|
i += (nullb->dev->blocksize >> SECTOR_SHIFT)) { |
|
if (test_bit(i, c_page->bitmap)) { |
|
offset = (i << SECTOR_SHIFT); |
|
memcpy(dst + offset, src + offset, |
|
nullb->dev->blocksize); |
|
__set_bit(i, t_page->bitmap); |
|
} |
|
} |
|
|
|
kunmap_atomic(dst); |
|
kunmap_atomic(src); |
|
|
|
ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page); |
|
null_free_page(ret); |
|
nullb->dev->curr_cache -= PAGE_SIZE; |
|
|
|
return 0; |
|
} |
|
|
|
static int null_make_cache_space(struct nullb *nullb, unsigned long n) |
|
{ |
|
int i, err, nr_pages; |
|
struct nullb_page *c_pages[FREE_BATCH]; |
|
unsigned long flushed = 0, one_round; |
|
|
|
again: |
|
if ((nullb->dev->cache_size * 1024 * 1024) > |
|
nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0) |
|
return 0; |
|
|
|
nr_pages = radix_tree_gang_lookup(&nullb->dev->cache, |
|
(void **)c_pages, nullb->cache_flush_pos, FREE_BATCH); |
|
/* |
|
* nullb_flush_cache_page could unlock before using the c_pages. To |
|
* avoid race, we don't allow page free |
|
*/ |
|
for (i = 0; i < nr_pages; i++) { |
|
nullb->cache_flush_pos = c_pages[i]->page->index; |
|
/* |
|
* We found the page which is being flushed to disk by other |
|
* threads |
|
*/ |
|
if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap)) |
|
c_pages[i] = NULL; |
|
else |
|
__set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap); |
|
} |
|
|
|
one_round = 0; |
|
for (i = 0; i < nr_pages; i++) { |
|
if (c_pages[i] == NULL) |
|
continue; |
|
err = null_flush_cache_page(nullb, c_pages[i]); |
|
if (err) |
|
return err; |
|
one_round++; |
|
} |
|
flushed += one_round << PAGE_SHIFT; |
|
|
|
if (n > flushed) { |
|
if (nr_pages == 0) |
|
nullb->cache_flush_pos = 0; |
|
if (one_round == 0) { |
|
/* give other threads a chance */ |
|
spin_unlock_irq(&nullb->lock); |
|
spin_lock_irq(&nullb->lock); |
|
} |
|
goto again; |
|
} |
|
return 0; |
|
} |
|
|
|
static int copy_to_nullb(struct nullb *nullb, struct page *source, |
|
unsigned int off, sector_t sector, size_t n, bool is_fua) |
|
{ |
|
size_t temp, count = 0; |
|
unsigned int offset; |
|
struct nullb_page *t_page; |
|
void *dst, *src; |
|
|
|
while (count < n) { |
|
temp = min_t(size_t, nullb->dev->blocksize, n - count); |
|
|
|
if (null_cache_active(nullb) && !is_fua) |
|
null_make_cache_space(nullb, PAGE_SIZE); |
|
|
|
offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; |
|
t_page = null_insert_page(nullb, sector, |
|
!null_cache_active(nullb) || is_fua); |
|
if (!t_page) |
|
return -ENOSPC; |
|
|
|
src = kmap_atomic(source); |
|
dst = kmap_atomic(t_page->page); |
|
memcpy(dst + offset, src + off + count, temp); |
|
kunmap_atomic(dst); |
|
kunmap_atomic(src); |
|
|
|
__set_bit(sector & SECTOR_MASK, t_page->bitmap); |
|
|
|
if (is_fua) |
|
null_free_sector(nullb, sector, true); |
|
|
|
count += temp; |
|
sector += temp >> SECTOR_SHIFT; |
|
} |
|
return 0; |
|
} |
|
|
|
static int copy_from_nullb(struct nullb *nullb, struct page *dest, |
|
unsigned int off, sector_t sector, size_t n) |
|
{ |
|
size_t temp, count = 0; |
|
unsigned int offset; |
|
struct nullb_page *t_page; |
|
void *dst, *src; |
|
|
|
while (count < n) { |
|
temp = min_t(size_t, nullb->dev->blocksize, n - count); |
|
|
|
offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; |
|
t_page = null_lookup_page(nullb, sector, false, |
|
!null_cache_active(nullb)); |
|
|
|
dst = kmap_atomic(dest); |
|
if (!t_page) { |
|
memset(dst + off + count, 0, temp); |
|
goto next; |
|
} |
|
src = kmap_atomic(t_page->page); |
|
memcpy(dst + off + count, src + offset, temp); |
|
kunmap_atomic(src); |
|
next: |
|
kunmap_atomic(dst); |
|
|
|
count += temp; |
|
sector += temp >> SECTOR_SHIFT; |
|
} |
|
return 0; |
|
} |
|
|
|
static void nullb_fill_pattern(struct nullb *nullb, struct page *page, |
|
unsigned int len, unsigned int off) |
|
{ |
|
void *dst; |
|
|
|
dst = kmap_atomic(page); |
|
memset(dst + off, 0xFF, len); |
|
kunmap_atomic(dst); |
|
} |
|
|
|
blk_status_t null_handle_discard(struct nullb_device *dev, |
|
sector_t sector, sector_t nr_sectors) |
|
{ |
|
struct nullb *nullb = dev->nullb; |
|
size_t n = nr_sectors << SECTOR_SHIFT; |
|
size_t temp; |
|
|
|
spin_lock_irq(&nullb->lock); |
|
while (n > 0) { |
|
temp = min_t(size_t, n, dev->blocksize); |
|
null_free_sector(nullb, sector, false); |
|
if (null_cache_active(nullb)) |
|
null_free_sector(nullb, sector, true); |
|
sector += temp >> SECTOR_SHIFT; |
|
n -= temp; |
|
} |
|
spin_unlock_irq(&nullb->lock); |
|
|
|
return BLK_STS_OK; |
|
} |
|
|
|
static int null_handle_flush(struct nullb *nullb) |
|
{ |
|
int err; |
|
|
|
if (!null_cache_active(nullb)) |
|
return 0; |
|
|
|
spin_lock_irq(&nullb->lock); |
|
while (true) { |
|
err = null_make_cache_space(nullb, |
|
nullb->dev->cache_size * 1024 * 1024); |
|
if (err || nullb->dev->curr_cache == 0) |
|
break; |
|
} |
|
|
|
WARN_ON(!radix_tree_empty(&nullb->dev->cache)); |
|
spin_unlock_irq(&nullb->lock); |
|
return err; |
|
} |
|
|
|
static int null_transfer(struct nullb *nullb, struct page *page, |
|
unsigned int len, unsigned int off, bool is_write, sector_t sector, |
|
bool is_fua) |
|
{ |
|
struct nullb_device *dev = nullb->dev; |
|
unsigned int valid_len = len; |
|
int err = 0; |
|
|
|
if (!is_write) { |
|
if (dev->zoned) |
|
valid_len = null_zone_valid_read_len(nullb, |
|
sector, len); |
|
|
|
if (valid_len) { |
|
err = copy_from_nullb(nullb, page, off, |
|
sector, valid_len); |
|
off += valid_len; |
|
len -= valid_len; |
|
} |
|
|
|
if (len) |
|
nullb_fill_pattern(nullb, page, len, off); |
|
flush_dcache_page(page); |
|
} else { |
|
flush_dcache_page(page); |
|
err = copy_to_nullb(nullb, page, off, sector, len, is_fua); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int null_handle_rq(struct nullb_cmd *cmd) |
|
{ |
|
struct request *rq = cmd->rq; |
|
struct nullb *nullb = cmd->nq->dev->nullb; |
|
int err; |
|
unsigned int len; |
|
sector_t sector = blk_rq_pos(rq); |
|
struct req_iterator iter; |
|
struct bio_vec bvec; |
|
|
|
spin_lock_irq(&nullb->lock); |
|
rq_for_each_segment(bvec, rq, iter) { |
|
len = bvec.bv_len; |
|
err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, |
|
op_is_write(req_op(rq)), sector, |
|
rq->cmd_flags & REQ_FUA); |
|
if (err) { |
|
spin_unlock_irq(&nullb->lock); |
|
return err; |
|
} |
|
sector += len >> SECTOR_SHIFT; |
|
} |
|
spin_unlock_irq(&nullb->lock); |
|
|
|
return 0; |
|
} |
|
|
|
static int null_handle_bio(struct nullb_cmd *cmd) |
|
{ |
|
struct bio *bio = cmd->bio; |
|
struct nullb *nullb = cmd->nq->dev->nullb; |
|
int err; |
|
unsigned int len; |
|
sector_t sector = bio->bi_iter.bi_sector; |
|
struct bio_vec bvec; |
|
struct bvec_iter iter; |
|
|
|
spin_lock_irq(&nullb->lock); |
|
bio_for_each_segment(bvec, bio, iter) { |
|
len = bvec.bv_len; |
|
err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, |
|
op_is_write(bio_op(bio)), sector, |
|
bio->bi_opf & REQ_FUA); |
|
if (err) { |
|
spin_unlock_irq(&nullb->lock); |
|
return err; |
|
} |
|
sector += len >> SECTOR_SHIFT; |
|
} |
|
spin_unlock_irq(&nullb->lock); |
|
return 0; |
|
} |
|
|
|
static void null_stop_queue(struct nullb *nullb) |
|
{ |
|
struct request_queue *q = nullb->q; |
|
|
|
if (nullb->dev->queue_mode == NULL_Q_MQ) |
|
blk_mq_stop_hw_queues(q); |
|
} |
|
|
|
static void null_restart_queue_async(struct nullb *nullb) |
|
{ |
|
struct request_queue *q = nullb->q; |
|
|
|
if (nullb->dev->queue_mode == NULL_Q_MQ) |
|
blk_mq_start_stopped_hw_queues(q, true); |
|
} |
|
|
|
static inline blk_status_t null_handle_throttled(struct nullb_cmd *cmd) |
|
{ |
|
struct nullb_device *dev = cmd->nq->dev; |
|
struct nullb *nullb = dev->nullb; |
|
blk_status_t sts = BLK_STS_OK; |
|
struct request *rq = cmd->rq; |
|
|
|
if (!hrtimer_active(&nullb->bw_timer)) |
|
hrtimer_restart(&nullb->bw_timer); |
|
|
|
if (atomic_long_sub_return(blk_rq_bytes(rq), &nullb->cur_bytes) < 0) { |
|
null_stop_queue(nullb); |
|
/* race with timer */ |
|
if (atomic_long_read(&nullb->cur_bytes) > 0) |
|
null_restart_queue_async(nullb); |
|
/* requeue request */ |
|
sts = BLK_STS_DEV_RESOURCE; |
|
} |
|
return sts; |
|
} |
|
|
|
static inline blk_status_t null_handle_badblocks(struct nullb_cmd *cmd, |
|
sector_t sector, |
|
sector_t nr_sectors) |
|
{ |
|
struct badblocks *bb = &cmd->nq->dev->badblocks; |
|
sector_t first_bad; |
|
int bad_sectors; |
|
|
|
if (badblocks_check(bb, sector, nr_sectors, &first_bad, &bad_sectors)) |
|
return BLK_STS_IOERR; |
|
|
|
return BLK_STS_OK; |
|
} |
|
|
|
static inline blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd, |
|
enum req_opf op, |
|
sector_t sector, |
|
sector_t nr_sectors) |
|
{ |
|
struct nullb_device *dev = cmd->nq->dev; |
|
int err; |
|
|
|
if (op == REQ_OP_DISCARD) |
|
return null_handle_discard(dev, sector, nr_sectors); |
|
|
|
if (dev->queue_mode == NULL_Q_BIO) |
|
err = null_handle_bio(cmd); |
|
else |
|
err = null_handle_rq(cmd); |
|
|
|
return errno_to_blk_status(err); |
|
} |
|
|
|
static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd) |
|
{ |
|
struct nullb_device *dev = cmd->nq->dev; |
|
struct bio *bio; |
|
|
|
if (dev->memory_backed) |
|
return; |
|
|
|
if (dev->queue_mode == NULL_Q_BIO && bio_op(cmd->bio) == REQ_OP_READ) { |
|
zero_fill_bio(cmd->bio); |
|
} else if (req_op(cmd->rq) == REQ_OP_READ) { |
|
__rq_for_each_bio(bio, cmd->rq) |
|
zero_fill_bio(bio); |
|
} |
|
} |
|
|
|
static inline void nullb_complete_cmd(struct nullb_cmd *cmd) |
|
{ |
|
/* |
|
* Since root privileges are required to configure the null_blk |
|
* driver, it is fine that this driver does not initialize the |
|
* data buffers of read commands. Zero-initialize these buffers |
|
* anyway if KMSAN is enabled to prevent that KMSAN complains |
|
* about null_blk not initializing read data buffers. |
|
*/ |
|
if (IS_ENABLED(CONFIG_KMSAN)) |
|
nullb_zero_read_cmd_buffer(cmd); |
|
|
|
/* Complete IO by inline, softirq or timer */ |
|
switch (cmd->nq->dev->irqmode) { |
|
case NULL_IRQ_SOFTIRQ: |
|
switch (cmd->nq->dev->queue_mode) { |
|
case NULL_Q_MQ: |
|
if (likely(!blk_should_fake_timeout(cmd->rq->q))) |
|
blk_mq_complete_request(cmd->rq); |
|
break; |
|
case NULL_Q_BIO: |
|
/* |
|
* XXX: no proper submitting cpu information available. |
|
*/ |
|
end_cmd(cmd); |
|
break; |
|
} |
|
break; |
|
case NULL_IRQ_NONE: |
|
end_cmd(cmd); |
|
break; |
|
case NULL_IRQ_TIMER: |
|
null_cmd_end_timer(cmd); |
|
break; |
|
} |
|
} |
|
|
|
blk_status_t null_process_cmd(struct nullb_cmd *cmd, |
|
enum req_opf op, sector_t sector, |
|
unsigned int nr_sectors) |
|
{ |
|
struct nullb_device *dev = cmd->nq->dev; |
|
blk_status_t ret; |
|
|
|
if (dev->badblocks.shift != -1) { |
|
ret = null_handle_badblocks(cmd, sector, nr_sectors); |
|
if (ret != BLK_STS_OK) |
|
return ret; |
|
} |
|
|
|
if (dev->memory_backed) |
|
return null_handle_memory_backed(cmd, op, sector, nr_sectors); |
|
|
|
return BLK_STS_OK; |
|
} |
|
|
|
static blk_status_t null_handle_cmd(struct nullb_cmd *cmd, sector_t sector, |
|
sector_t nr_sectors, enum req_opf op) |
|
{ |
|
struct nullb_device *dev = cmd->nq->dev; |
|
struct nullb *nullb = dev->nullb; |
|
blk_status_t sts; |
|
|
|
if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) { |
|
sts = null_handle_throttled(cmd); |
|
if (sts != BLK_STS_OK) |
|
return sts; |
|
} |
|
|
|
if (op == REQ_OP_FLUSH) { |
|
cmd->error = errno_to_blk_status(null_handle_flush(nullb)); |
|
goto out; |
|
} |
|
|
|
if (dev->zoned) |
|
sts = null_process_zoned_cmd(cmd, op, sector, nr_sectors); |
|
else |
|
sts = null_process_cmd(cmd, op, sector, nr_sectors); |
|
|
|
/* Do not overwrite errors (e.g. timeout errors) */ |
|
if (cmd->error == BLK_STS_OK) |
|
cmd->error = sts; |
|
|
|
out: |
|
nullb_complete_cmd(cmd); |
|
return BLK_STS_OK; |
|
} |
|
|
|
static enum hrtimer_restart nullb_bwtimer_fn(struct hrtimer *timer) |
|
{ |
|
struct nullb *nullb = container_of(timer, struct nullb, bw_timer); |
|
ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL); |
|
unsigned int mbps = nullb->dev->mbps; |
|
|
|
if (atomic_long_read(&nullb->cur_bytes) == mb_per_tick(mbps)) |
|
return HRTIMER_NORESTART; |
|
|
|
atomic_long_set(&nullb->cur_bytes, mb_per_tick(mbps)); |
|
null_restart_queue_async(nullb); |
|
|
|
hrtimer_forward_now(&nullb->bw_timer, timer_interval); |
|
|
|
return HRTIMER_RESTART; |
|
} |
|
|
|
static void nullb_setup_bwtimer(struct nullb *nullb) |
|
{ |
|
ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL); |
|
|
|
hrtimer_init(&nullb->bw_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
|
nullb->bw_timer.function = nullb_bwtimer_fn; |
|
atomic_long_set(&nullb->cur_bytes, mb_per_tick(nullb->dev->mbps)); |
|
hrtimer_start(&nullb->bw_timer, timer_interval, HRTIMER_MODE_REL); |
|
} |
|
|
|
static struct nullb_queue *nullb_to_queue(struct nullb *nullb) |
|
{ |
|
int index = 0; |
|
|
|
if (nullb->nr_queues != 1) |
|
index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); |
|
|
|
return &nullb->queues[index]; |
|
} |
|
|
|
static blk_qc_t null_submit_bio(struct bio *bio) |
|
{ |
|
sector_t sector = bio->bi_iter.bi_sector; |
|
sector_t nr_sectors = bio_sectors(bio); |
|
struct nullb *nullb = bio->bi_bdev->bd_disk->private_data; |
|
struct nullb_queue *nq = nullb_to_queue(nullb); |
|
struct nullb_cmd *cmd; |
|
|
|
cmd = alloc_cmd(nq, 1); |
|
cmd->bio = bio; |
|
|
|
null_handle_cmd(cmd, sector, nr_sectors, bio_op(bio)); |
|
return BLK_QC_T_NONE; |
|
} |
|
|
|
static bool should_timeout_request(struct request *rq) |
|
{ |
|
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
|
if (g_timeout_str[0]) |
|
return should_fail(&null_timeout_attr, 1); |
|
#endif |
|
return false; |
|
} |
|
|
|
static bool should_requeue_request(struct request *rq) |
|
{ |
|
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
|
if (g_requeue_str[0]) |
|
return should_fail(&null_requeue_attr, 1); |
|
#endif |
|
return false; |
|
} |
|
|
|
static enum blk_eh_timer_return null_timeout_rq(struct request *rq, bool res) |
|
{ |
|
struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq); |
|
|
|
pr_info("rq %p timed out\n", rq); |
|
|
|
/* |
|
* If the device is marked as blocking (i.e. memory backed or zoned |
|
* device), the submission path may be blocked waiting for resources |
|
* and cause real timeouts. For these real timeouts, the submission |
|
* path will complete the request using blk_mq_complete_request(). |
|
* Only fake timeouts need to execute blk_mq_complete_request() here. |
|
*/ |
|
cmd->error = BLK_STS_TIMEOUT; |
|
if (cmd->fake_timeout) |
|
blk_mq_complete_request(rq); |
|
return BLK_EH_DONE; |
|
} |
|
|
|
static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx, |
|
const struct blk_mq_queue_data *bd) |
|
{ |
|
struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
|
struct nullb_queue *nq = hctx->driver_data; |
|
sector_t nr_sectors = blk_rq_sectors(bd->rq); |
|
sector_t sector = blk_rq_pos(bd->rq); |
|
|
|
might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); |
|
|
|
if (nq->dev->irqmode == NULL_IRQ_TIMER) { |
|
hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
|
cmd->timer.function = null_cmd_timer_expired; |
|
} |
|
cmd->rq = bd->rq; |
|
cmd->error = BLK_STS_OK; |
|
cmd->nq = nq; |
|
cmd->fake_timeout = should_timeout_request(bd->rq); |
|
|
|
blk_mq_start_request(bd->rq); |
|
|
|
if (should_requeue_request(bd->rq)) { |
|
/* |
|
* Alternate between hitting the core BUSY path, and the |
|
* driver driven requeue path |
|
*/ |
|
nq->requeue_selection++; |
|
if (nq->requeue_selection & 1) |
|
return BLK_STS_RESOURCE; |
|
else { |
|
blk_mq_requeue_request(bd->rq, true); |
|
return BLK_STS_OK; |
|
} |
|
} |
|
if (cmd->fake_timeout) |
|
return BLK_STS_OK; |
|
|
|
return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq)); |
|
} |
|
|
|
static void cleanup_queue(struct nullb_queue *nq) |
|
{ |
|
kfree(nq->tag_map); |
|
kfree(nq->cmds); |
|
} |
|
|
|
static void cleanup_queues(struct nullb *nullb) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < nullb->nr_queues; i++) |
|
cleanup_queue(&nullb->queues[i]); |
|
|
|
kfree(nullb->queues); |
|
} |
|
|
|
static void null_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) |
|
{ |
|
struct nullb_queue *nq = hctx->driver_data; |
|
struct nullb *nullb = nq->dev->nullb; |
|
|
|
nullb->nr_queues--; |
|
} |
|
|
|
static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) |
|
{ |
|
init_waitqueue_head(&nq->wait); |
|
nq->queue_depth = nullb->queue_depth; |
|
nq->dev = nullb->dev; |
|
} |
|
|
|
static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, |
|
unsigned int hctx_idx) |
|
{ |
|
struct nullb *nullb = hctx->queue->queuedata; |
|
struct nullb_queue *nq; |
|
|
|
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
|
if (g_init_hctx_str[0] && should_fail(&null_init_hctx_attr, 1)) |
|
return -EFAULT; |
|
#endif |
|
|
|
nq = &nullb->queues[hctx_idx]; |
|
hctx->driver_data = nq; |
|
null_init_queue(nullb, nq); |
|
nullb->nr_queues++; |
|
|
|
return 0; |
|
} |
|
|
|
static const struct blk_mq_ops null_mq_ops = { |
|
.queue_rq = null_queue_rq, |
|
.complete = null_complete_rq, |
|
.timeout = null_timeout_rq, |
|
.init_hctx = null_init_hctx, |
|
.exit_hctx = null_exit_hctx, |
|
}; |
|
|
|
static void null_del_dev(struct nullb *nullb) |
|
{ |
|
struct nullb_device *dev; |
|
|
|
if (!nullb) |
|
return; |
|
|
|
dev = nullb->dev; |
|
|
|
ida_simple_remove(&nullb_indexes, nullb->index); |
|
|
|
list_del_init(&nullb->list); |
|
|
|
del_gendisk(nullb->disk); |
|
|
|
if (test_bit(NULLB_DEV_FL_THROTTLED, &nullb->dev->flags)) { |
|
hrtimer_cancel(&nullb->bw_timer); |
|
atomic_long_set(&nullb->cur_bytes, LONG_MAX); |
|
null_restart_queue_async(nullb); |
|
} |
|
|
|
blk_cleanup_disk(nullb->disk); |
|
if (dev->queue_mode == NULL_Q_MQ && |
|
nullb->tag_set == &nullb->__tag_set) |
|
blk_mq_free_tag_set(nullb->tag_set); |
|
cleanup_queues(nullb); |
|
if (null_cache_active(nullb)) |
|
null_free_device_storage(nullb->dev, true); |
|
kfree(nullb); |
|
dev->nullb = NULL; |
|
} |
|
|
|
static void null_config_discard(struct nullb *nullb) |
|
{ |
|
if (nullb->dev->discard == false) |
|
return; |
|
|
|
if (!nullb->dev->memory_backed) { |
|
nullb->dev->discard = false; |
|
pr_info("discard option is ignored without memory backing\n"); |
|
return; |
|
} |
|
|
|
if (nullb->dev->zoned) { |
|
nullb->dev->discard = false; |
|
pr_info("discard option is ignored in zoned mode\n"); |
|
return; |
|
} |
|
|
|
nullb->q->limits.discard_granularity = nullb->dev->blocksize; |
|
nullb->q->limits.discard_alignment = nullb->dev->blocksize; |
|
blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9); |
|
blk_queue_flag_set(QUEUE_FLAG_DISCARD, nullb->q); |
|
} |
|
|
|
static const struct block_device_operations null_bio_ops = { |
|
.owner = THIS_MODULE, |
|
.submit_bio = null_submit_bio, |
|
.report_zones = null_report_zones, |
|
}; |
|
|
|
static const struct block_device_operations null_rq_ops = { |
|
.owner = THIS_MODULE, |
|
.report_zones = null_report_zones, |
|
}; |
|
|
|
static int setup_commands(struct nullb_queue *nq) |
|
{ |
|
struct nullb_cmd *cmd; |
|
int i, tag_size; |
|
|
|
nq->cmds = kcalloc(nq->queue_depth, sizeof(*cmd), GFP_KERNEL); |
|
if (!nq->cmds) |
|
return -ENOMEM; |
|
|
|
tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; |
|
nq->tag_map = kcalloc(tag_size, sizeof(unsigned long), GFP_KERNEL); |
|
if (!nq->tag_map) { |
|
kfree(nq->cmds); |
|
return -ENOMEM; |
|
} |
|
|
|
for (i = 0; i < nq->queue_depth; i++) { |
|
cmd = &nq->cmds[i]; |
|
cmd->tag = -1U; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int setup_queues(struct nullb *nullb) |
|
{ |
|
nullb->queues = kcalloc(nr_cpu_ids, sizeof(struct nullb_queue), |
|
GFP_KERNEL); |
|
if (!nullb->queues) |
|
return -ENOMEM; |
|
|
|
nullb->queue_depth = nullb->dev->hw_queue_depth; |
|
|
|
return 0; |
|
} |
|
|
|
static int init_driver_queues(struct nullb *nullb) |
|
{ |
|
struct nullb_queue *nq; |
|
int i, ret = 0; |
|
|
|
for (i = 0; i < nullb->dev->submit_queues; i++) { |
|
nq = &nullb->queues[i]; |
|
|
|
null_init_queue(nullb, nq); |
|
|
|
ret = setup_commands(nq); |
|
if (ret) |
|
return ret; |
|
nullb->nr_queues++; |
|
} |
|
return 0; |
|
} |
|
|
|
static int null_gendisk_register(struct nullb *nullb) |
|
{ |
|
sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT; |
|
struct gendisk *disk = nullb->disk; |
|
|
|
set_capacity(disk, size); |
|
|
|
disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO; |
|
disk->major = null_major; |
|
disk->first_minor = nullb->index; |
|
disk->minors = 1; |
|
if (queue_is_mq(nullb->q)) |
|
disk->fops = &null_rq_ops; |
|
else |
|
disk->fops = &null_bio_ops; |
|
disk->private_data = nullb; |
|
strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN); |
|
|
|
if (nullb->dev->zoned) { |
|
int ret = null_register_zoned_dev(nullb); |
|
|
|
if (ret) |
|
return ret; |
|
} |
|
|
|
return add_disk(disk); |
|
} |
|
|
|
static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set) |
|
{ |
|
set->ops = &null_mq_ops; |
|
set->nr_hw_queues = nullb ? nullb->dev->submit_queues : |
|
g_submit_queues; |
|
set->queue_depth = nullb ? nullb->dev->hw_queue_depth : |
|
g_hw_queue_depth; |
|
set->numa_node = nullb ? nullb->dev->home_node : g_home_node; |
|
set->cmd_size = sizeof(struct nullb_cmd); |
|
set->flags = BLK_MQ_F_SHOULD_MERGE; |
|
if (g_no_sched) |
|
set->flags |= BLK_MQ_F_NO_SCHED; |
|
if (g_shared_tag_bitmap) |
|
set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; |
|
set->driver_data = NULL; |
|
|
|
if ((nullb && nullb->dev->blocking) || g_blocking) |
|
set->flags |= BLK_MQ_F_BLOCKING; |
|
|
|
return blk_mq_alloc_tag_set(set); |
|
} |
|
|
|
static int null_validate_conf(struct nullb_device *dev) |
|
{ |
|
dev->blocksize = round_down(dev->blocksize, 512); |
|
dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096); |
|
|
|
if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) { |
|
if (dev->submit_queues != nr_online_nodes) |
|
dev->submit_queues = nr_online_nodes; |
|
} else if (dev->submit_queues > nr_cpu_ids) |
|
dev->submit_queues = nr_cpu_ids; |
|
else if (dev->submit_queues == 0) |
|
dev->submit_queues = 1; |
|
|
|
dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ); |
|
dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER); |
|
|
|
/* Do memory allocation, so set blocking */ |
|
if (dev->memory_backed) |
|
dev->blocking = true; |
|
else /* cache is meaningless */ |
|
dev->cache_size = 0; |
|
dev->cache_size = min_t(unsigned long, ULONG_MAX / 1024 / 1024, |
|
dev->cache_size); |
|
dev->mbps = min_t(unsigned int, 1024 * 40, dev->mbps); |
|
/* can not stop a queue */ |
|
if (dev->queue_mode == NULL_Q_BIO) |
|
dev->mbps = 0; |
|
|
|
if (dev->zoned && |
|
(!dev->zone_size || !is_power_of_2(dev->zone_size))) { |
|
pr_err("zone_size must be power-of-two\n"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
|
static bool __null_setup_fault(struct fault_attr *attr, char *str) |
|
{ |
|
if (!str[0]) |
|
return true; |
|
|
|
if (!setup_fault_attr(attr, str)) |
|
return false; |
|
|
|
attr->verbose = 0; |
|
return true; |
|
} |
|
#endif |
|
|
|
static bool null_setup_fault(void) |
|
{ |
|
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION |
|
if (!__null_setup_fault(&null_timeout_attr, g_timeout_str)) |
|
return false; |
|
if (!__null_setup_fault(&null_requeue_attr, g_requeue_str)) |
|
return false; |
|
if (!__null_setup_fault(&null_init_hctx_attr, g_init_hctx_str)) |
|
return false; |
|
#endif |
|
return true; |
|
} |
|
|
|
static int null_add_dev(struct nullb_device *dev) |
|
{ |
|
struct nullb *nullb; |
|
int rv; |
|
|
|
rv = null_validate_conf(dev); |
|
if (rv) |
|
return rv; |
|
|
|
nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node); |
|
if (!nullb) { |
|
rv = -ENOMEM; |
|
goto out; |
|
} |
|
nullb->dev = dev; |
|
dev->nullb = nullb; |
|
|
|
spin_lock_init(&nullb->lock); |
|
|
|
rv = setup_queues(nullb); |
|
if (rv) |
|
goto out_free_nullb; |
|
|
|
if (dev->queue_mode == NULL_Q_MQ) { |
|
if (shared_tags) { |
|
nullb->tag_set = &tag_set; |
|
rv = 0; |
|
} else { |
|
nullb->tag_set = &nullb->__tag_set; |
|
rv = null_init_tag_set(nullb, nullb->tag_set); |
|
} |
|
|
|
if (rv) |
|
goto out_cleanup_queues; |
|
|
|
if (!null_setup_fault()) |
|
goto out_cleanup_tags; |
|
|
|
nullb->tag_set->timeout = 5 * HZ; |
|
nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb); |
|
if (IS_ERR(nullb->disk)) { |
|
rv = PTR_ERR(nullb->disk); |
|
goto out_cleanup_tags; |
|
} |
|
nullb->q = nullb->disk->queue; |
|
} else if (dev->queue_mode == NULL_Q_BIO) { |
|
rv = -ENOMEM; |
|
nullb->disk = blk_alloc_disk(nullb->dev->home_node); |
|
if (!nullb->disk) |
|
goto out_cleanup_queues; |
|
|
|
nullb->q = nullb->disk->queue; |
|
rv = init_driver_queues(nullb); |
|
if (rv) |
|
goto out_cleanup_disk; |
|
} |
|
|
|
if (dev->mbps) { |
|
set_bit(NULLB_DEV_FL_THROTTLED, &dev->flags); |
|
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, true); |
|
} |
|
|
|
if (dev->zoned) { |
|
rv = null_init_zoned_dev(dev, nullb->q); |
|
if (rv) |
|
goto out_cleanup_disk; |
|
} |
|
|
|
nullb->q->queuedata = nullb; |
|
blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q); |
|
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q); |
|
|
|
mutex_lock(&lock); |
|
nullb->index = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL); |
|
dev->index = nullb->index; |
|
mutex_unlock(&lock); |
|
|
|
blk_queue_logical_block_size(nullb->q, dev->blocksize); |
|
blk_queue_physical_block_size(nullb->q, dev->blocksize); |
|
if (!dev->max_sectors) |
|
dev->max_sectors = queue_max_hw_sectors(nullb->q); |
|
dev->max_sectors = min_t(unsigned int, dev->max_sectors, |
|
BLK_DEF_MAX_SECTORS); |
|
blk_queue_max_hw_sectors(nullb->q, dev->max_sectors); |
|
|
|
if (dev->virt_boundary) |
|
blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1); |
|
|
|
null_config_discard(nullb); |
|
|
|
sprintf(nullb->disk_name, "nullb%d", nullb->index); |
|
|
|
rv = null_gendisk_register(nullb); |
|
if (rv) |
|
goto out_cleanup_zone; |
|
|
|
mutex_lock(&lock); |
|
list_add_tail(&nullb->list, &nullb_list); |
|
mutex_unlock(&lock); |
|
|
|
return 0; |
|
out_cleanup_zone: |
|
null_free_zoned_dev(dev); |
|
out_cleanup_disk: |
|
blk_cleanup_disk(nullb->disk); |
|
out_cleanup_tags: |
|
if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set) |
|
blk_mq_free_tag_set(nullb->tag_set); |
|
out_cleanup_queues: |
|
cleanup_queues(nullb); |
|
out_free_nullb: |
|
kfree(nullb); |
|
dev->nullb = NULL; |
|
out: |
|
return rv; |
|
} |
|
|
|
static int __init null_init(void) |
|
{ |
|
int ret = 0; |
|
unsigned int i; |
|
struct nullb *nullb; |
|
struct nullb_device *dev; |
|
|
|
if (g_bs > PAGE_SIZE) { |
|
pr_warn("invalid block size\n"); |
|
pr_warn("defaults block size to %lu\n", PAGE_SIZE); |
|
g_bs = PAGE_SIZE; |
|
} |
|
|
|
if (g_max_sectors > BLK_DEF_MAX_SECTORS) { |
|
pr_warn("invalid max sectors\n"); |
|
pr_warn("defaults max sectors to %u\n", BLK_DEF_MAX_SECTORS); |
|
g_max_sectors = BLK_DEF_MAX_SECTORS; |
|
} |
|
|
|
if (g_home_node != NUMA_NO_NODE && g_home_node >= nr_online_nodes) { |
|
pr_err("invalid home_node value\n"); |
|
g_home_node = NUMA_NO_NODE; |
|
} |
|
|
|
if (g_queue_mode == NULL_Q_RQ) { |
|
pr_err("legacy IO path no longer available\n"); |
|
return -EINVAL; |
|
} |
|
if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) { |
|
if (g_submit_queues != nr_online_nodes) { |
|
pr_warn("submit_queues param is set to %u.\n", |
|
nr_online_nodes); |
|
g_submit_queues = nr_online_nodes; |
|
} |
|
} else if (g_submit_queues > nr_cpu_ids) |
|
g_submit_queues = nr_cpu_ids; |
|
else if (g_submit_queues <= 0) |
|
g_submit_queues = 1; |
|
|
|
if (g_queue_mode == NULL_Q_MQ && shared_tags) { |
|
ret = null_init_tag_set(NULL, &tag_set); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
config_group_init(&nullb_subsys.su_group); |
|
mutex_init(&nullb_subsys.su_mutex); |
|
|
|
ret = configfs_register_subsystem(&nullb_subsys); |
|
if (ret) |
|
goto err_tagset; |
|
|
|
mutex_init(&lock); |
|
|
|
null_major = register_blkdev(0, "nullb"); |
|
if (null_major < 0) { |
|
ret = null_major; |
|
goto err_conf; |
|
} |
|
|
|
for (i = 0; i < nr_devices; i++) { |
|
dev = null_alloc_dev(); |
|
if (!dev) { |
|
ret = -ENOMEM; |
|
goto err_dev; |
|
} |
|
ret = null_add_dev(dev); |
|
if (ret) { |
|
null_free_dev(dev); |
|
goto err_dev; |
|
} |
|
} |
|
|
|
pr_info("module loaded\n"); |
|
return 0; |
|
|
|
err_dev: |
|
while (!list_empty(&nullb_list)) { |
|
nullb = list_entry(nullb_list.next, struct nullb, list); |
|
dev = nullb->dev; |
|
null_del_dev(nullb); |
|
null_free_dev(dev); |
|
} |
|
unregister_blkdev(null_major, "nullb"); |
|
err_conf: |
|
configfs_unregister_subsystem(&nullb_subsys); |
|
err_tagset: |
|
if (g_queue_mode == NULL_Q_MQ && shared_tags) |
|
blk_mq_free_tag_set(&tag_set); |
|
return ret; |
|
} |
|
|
|
static void __exit null_exit(void) |
|
{ |
|
struct nullb *nullb; |
|
|
|
configfs_unregister_subsystem(&nullb_subsys); |
|
|
|
unregister_blkdev(null_major, "nullb"); |
|
|
|
mutex_lock(&lock); |
|
while (!list_empty(&nullb_list)) { |
|
struct nullb_device *dev; |
|
|
|
nullb = list_entry(nullb_list.next, struct nullb, list); |
|
dev = nullb->dev; |
|
null_del_dev(nullb); |
|
null_free_dev(dev); |
|
} |
|
mutex_unlock(&lock); |
|
|
|
if (g_queue_mode == NULL_Q_MQ && shared_tags) |
|
blk_mq_free_tag_set(&tag_set); |
|
} |
|
|
|
module_init(null_init); |
|
module_exit(null_exit); |
|
|
|
MODULE_AUTHOR("Jens Axboe <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|