1909 lines
45 KiB
C
1909 lines
45 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and
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* Shaohua Li <shli@fb.com>
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*/
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#include <linux/module.h>
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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 PAGE_SECTORS_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
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#define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT)
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#define SECTOR_MASK (PAGE_SECTORS - 1)
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#define FREE_BATCH 16
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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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#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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* 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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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 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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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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#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
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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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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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#endif
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static int g_queue_mode = NULL_Q_MQ;
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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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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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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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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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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 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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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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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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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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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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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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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 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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/* 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 uninitialized_var(new_value); \
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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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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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if (!nullb)
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return 0;
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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(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_nr_conv, uint, NULL);
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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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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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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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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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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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return count;
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}
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CONFIGFS_ATTR(nullb_device_, power);
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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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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_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_nr_conv,
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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)
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{
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struct nullb_device *dev;
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dev = null_alloc_dev();
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if (!dev)
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return ERR_PTR(-ENOMEM);
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config_item_init_type_name(&dev->item, name, &nullb_device_type);
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return &dev->item;
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}
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static void
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nullb_group_drop_item(struct config_group *group, struct config_item *item)
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{
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struct nullb_device *dev = to_nullb_device(item);
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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_nr_conv\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->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_nr_conv = g_zone_nr_conv;
|
|
return dev;
|
|
}
|
|
|
|
static void null_free_dev(struct nullb_device *dev)
|
|
{
|
|
if (!dev)
|
|
return;
|
|
|
|
null_zone_exit(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->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);
|
|
}
|
|
|
|
static void null_handle_discard(struct nullb *nullb, sector_t sector, size_t n)
|
|
{
|
|
size_t temp;
|
|
|
|
spin_lock_irq(&nullb->lock);
|
|
while (n > 0) {
|
|
temp = min_t(size_t, n, nullb->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);
|
|
}
|
|
|
|
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;
|
|
struct req_iterator iter;
|
|
struct bio_vec bvec;
|
|
|
|
sector = blk_rq_pos(rq);
|
|
|
|
if (req_op(rq) == REQ_OP_DISCARD) {
|
|
null_handle_discard(nullb, sector, blk_rq_bytes(rq));
|
|
return 0;
|
|
}
|
|
|
|
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,
|
|
req_op(rq) & 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;
|
|
struct bio_vec bvec;
|
|
struct bvec_iter iter;
|
|
|
|
sector = bio->bi_iter.bi_sector;
|
|
|
|
if (bio_op(bio) == REQ_OP_DISCARD) {
|
|
null_handle_discard(nullb, sector,
|
|
bio_sectors(bio) << SECTOR_SHIFT);
|
|
return 0;
|
|
}
|
|
|
|
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)
|
|
{
|
|
struct nullb_device *dev = cmd->nq->dev;
|
|
int err;
|
|
|
|
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 inline void nullb_complete_cmd(struct nullb_cmd *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:
|
|
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;
|
|
}
|
|
}
|
|
|
|
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 (nullb->dev->badblocks.shift != -1) {
|
|
cmd->error = null_handle_badblocks(cmd, sector, nr_sectors);
|
|
if (cmd->error != BLK_STS_OK)
|
|
goto out;
|
|
}
|
|
|
|
if (dev->memory_backed)
|
|
cmd->error = null_handle_memory_backed(cmd, op);
|
|
|
|
if (!cmd->error && dev->zoned)
|
|
cmd->error = null_handle_zoned(cmd, op, sector, nr_sectors);
|
|
|
|
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_queue_bio(struct request_queue *q, struct bio *bio)
|
|
{
|
|
sector_t sector = bio->bi_iter.bi_sector;
|
|
sector_t nr_sectors = bio_sectors(bio);
|
|
struct nullb *nullb = q->queuedata;
|
|
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)
|
|
{
|
|
pr_info("rq %p timed out\n", rq);
|
|
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->nq = nq;
|
|
|
|
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 (should_timeout_request(bd->rq))
|
|
return BLK_STS_OK;
|
|
|
|
return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq));
|
|
}
|
|
|
|
static const struct blk_mq_ops null_mq_ops = {
|
|
.queue_rq = null_queue_rq,
|
|
.complete = null_complete_rq,
|
|
.timeout = null_timeout_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_del_dev(struct nullb *nullb)
|
|
{
|
|
struct nullb_device *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_queue(nullb->q);
|
|
if (dev->queue_mode == NULL_Q_MQ &&
|
|
nullb->tag_set == &nullb->__tag_set)
|
|
blk_mq_free_tag_set(nullb->tag_set);
|
|
put_disk(nullb->disk);
|
|
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;
|
|
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_ops = {
|
|
.owner = THIS_MODULE,
|
|
.report_zones = null_report_zones,
|
|
};
|
|
|
|
static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
|
|
{
|
|
BUG_ON(!nullb);
|
|
BUG_ON(!nq);
|
|
|
|
init_waitqueue_head(&nq->wait);
|
|
nq->queue_depth = nullb->queue_depth;
|
|
nq->dev = nullb->dev;
|
|
}
|
|
|
|
static void null_init_queues(struct nullb *nullb)
|
|
{
|
|
struct request_queue *q = nullb->q;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct nullb_queue *nq;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (!hctx->nr_ctx || !hctx->tags)
|
|
continue;
|
|
nq = &nullb->queues[i];
|
|
hctx->driver_data = nq;
|
|
null_init_queue(nullb, nq);
|
|
nullb->nr_queues++;
|
|
}
|
|
}
|
|
|
|
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(nullb->dev->submit_queues,
|
|
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;
|
|
|
|
disk = nullb->disk = alloc_disk_node(1, nullb->dev->home_node);
|
|
if (!disk)
|
|
return -ENOMEM;
|
|
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->fops = &null_ops;
|
|
disk->private_data = nullb;
|
|
disk->queue = nullb->q;
|
|
strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
|
|
|
|
#ifdef CONFIG_BLK_DEV_ZONED
|
|
if (nullb->dev->zoned) {
|
|
if (queue_is_mq(nullb->q)) {
|
|
int ret = blk_revalidate_disk_zones(disk);
|
|
if (ret)
|
|
return ret;
|
|
} else {
|
|
blk_queue_chunk_sectors(nullb->q,
|
|
nullb->dev->zone_size_sects);
|
|
nullb->q->nr_zones = blkdev_nr_zones(disk);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
add_disk(disk);
|
|
return 0;
|
|
}
|
|
|
|
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;
|
|
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;
|
|
#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_queues;
|
|
|
|
nullb->tag_set->timeout = 5 * HZ;
|
|
nullb->q = blk_mq_init_queue(nullb->tag_set);
|
|
if (IS_ERR(nullb->q)) {
|
|
rv = -ENOMEM;
|
|
goto out_cleanup_tags;
|
|
}
|
|
null_init_queues(nullb);
|
|
} else if (dev->queue_mode == NULL_Q_BIO) {
|
|
nullb->q = blk_alloc_queue_node(GFP_KERNEL, dev->home_node);
|
|
if (!nullb->q) {
|
|
rv = -ENOMEM;
|
|
goto out_cleanup_queues;
|
|
}
|
|
blk_queue_make_request(nullb->q, null_queue_bio);
|
|
rv = init_driver_queues(nullb);
|
|
if (rv)
|
|
goto out_cleanup_blk_queue;
|
|
}
|
|
|
|
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_zone_init(dev);
|
|
if (rv)
|
|
goto out_cleanup_blk_queue;
|
|
|
|
nullb->q->limits.zoned = BLK_ZONED_HM;
|
|
blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, nullb->q);
|
|
blk_queue_required_elevator_features(nullb->q,
|
|
ELEVATOR_F_ZBD_SEQ_WRITE);
|
|
}
|
|
|
|
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);
|
|
|
|
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:
|
|
if (dev->zoned)
|
|
null_zone_exit(dev);
|
|
out_cleanup_blk_queue:
|
|
blk_cleanup_queue(nullb->q);
|
|
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);
|
|
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_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 <axboe@kernel.dk>");
|
|
MODULE_LICENSE("GPL");
|