1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __BLK_NULL_BLK_H
3#define __BLK_NULL_BLK_H
4
5#undef pr_fmt
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/blkdev.h>
9#include <linux/slab.h>
10#include <linux/blk-mq.h>
11#include <linux/hrtimer.h>
12#include <linux/configfs.h>
13#include <linux/badblocks.h>
14#include <linux/fault-inject.h>
15#include <linux/spinlock.h>
16#include <linux/mutex.h>
17
18struct nullb_cmd {
19 blk_status_t error;
20 bool fake_timeout;
21 struct nullb_queue *nq;
22 struct hrtimer timer;
23};
24
25struct nullb_queue {
26 struct nullb_device *dev;
27 unsigned int requeue_selection;
28
29 struct list_head poll_list;
30 spinlock_t poll_lock;
31};
32
33struct nullb_zone {
34 /*
35 * Zone lock to prevent concurrent modification of a zone write
36 * pointer position and condition: with memory backing, a write
37 * command execution may sleep on memory allocation. For this case,
38 * use mutex as the zone lock. Otherwise, use the spinlock for
39 * locking the zone.
40 */
41 union {
42 spinlock_t spinlock;
43 struct mutex mutex;
44 };
45 enum blk_zone_type type;
46 enum blk_zone_cond cond;
47 sector_t start;
48 sector_t wp;
49 unsigned int len;
50 unsigned int capacity;
51};
52
53struct nullb_device {
54 struct nullb *nullb;
55 struct config_group group;
56#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
57 struct fault_config timeout_config;
58 struct fault_config requeue_config;
59 struct fault_config init_hctx_fault_config;
60#endif
61 struct radix_tree_root data; /* data stored in the disk */
62 struct radix_tree_root cache; /* disk cache data */
63 unsigned long flags; /* device flags */
64 unsigned int curr_cache;
65 struct badblocks badblocks;
66 bool badblocks_once;
67 bool badblocks_partial_io;
68
69 unsigned int nr_zones;
70 unsigned int nr_zones_imp_open;
71 unsigned int nr_zones_exp_open;
72 unsigned int nr_zones_closed;
73 unsigned int imp_close_zone_no;
74 struct nullb_zone *zones;
75 sector_t zone_size_sects;
76 bool need_zone_res_mgmt;
77 spinlock_t zone_res_lock;
78
79 unsigned long size; /* device size in MB */
80 unsigned long completion_nsec; /* time in ns to complete a request */
81 unsigned long cache_size; /* disk cache size in MB */
82 unsigned long zone_size; /* zone size in MB if device is zoned */
83 unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
84 unsigned int zone_nr_conv; /* number of conventional zones */
85 unsigned int zone_max_open; /* max number of open zones */
86 unsigned int zone_max_active; /* max number of active zones */
87 unsigned int zone_append_max_sectors; /* Max sectors per zone append command */
88 unsigned int submit_queues; /* number of submission queues */
89 unsigned int prev_submit_queues; /* number of submission queues before change */
90 unsigned int poll_queues; /* number of IOPOLL submission queues */
91 unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */
92 unsigned int home_node; /* home node for the device */
93 unsigned int queue_mode; /* block interface */
94 unsigned int blocksize; /* block size */
95 unsigned int max_sectors; /* Max sectors per command */
96 unsigned int irqmode; /* IRQ completion handler */
97 unsigned int hw_queue_depth; /* queue depth */
98 unsigned int index; /* index of the disk, only valid with a disk */
99 unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
100 bool blocking; /* blocking blk-mq device */
101 bool use_per_node_hctx; /* use per-node allocation for hardware context */
102 bool power; /* power on/off the device */
103 bool memory_backed; /* if data is stored in memory */
104 bool discard; /* if support discard */
105 bool zoned; /* if device is zoned */
106 bool zone_full; /* Initialize zones to be full */
107 bool virt_boundary; /* virtual boundary on/off for the device */
108 bool no_sched; /* no IO scheduler for the device */
109 bool shared_tags; /* share tag set between devices for blk-mq */
110 bool shared_tag_bitmap; /* use hostwide shared tags */
111 bool fua; /* Support FUA */
112 bool rotational; /* Fake rotational device */
113};
114
115struct nullb {
116 struct nullb_device *dev;
117 struct list_head list;
118 unsigned int index;
119 struct request_queue *q;
120 struct gendisk *disk;
121 struct blk_mq_tag_set *tag_set;
122 struct blk_mq_tag_set __tag_set;
123 atomic_long_t cur_bytes;
124 struct hrtimer bw_timer;
125 unsigned long cache_flush_pos;
126 spinlock_t lock;
127
128 struct nullb_queue *queues;
129 char disk_name[DISK_NAME_LEN];
130};
131
132blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
133 sector_t nr_sectors);
134blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op,
135 sector_t sector, unsigned int nr_sectors);
136blk_status_t null_handle_badblocks(struct nullb_cmd *cmd, sector_t sector,
137 unsigned int *nr_sectors);
138blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd, enum req_op op,
139 sector_t sector, sector_t nr_sectors);
140
141#ifdef CONFIG_BLK_DEV_ZONED
142int null_init_zoned_dev(struct nullb_device *dev, struct queue_limits *lim);
143int null_register_zoned_dev(struct nullb *nullb);
144void null_free_zoned_dev(struct nullb_device *dev);
145int null_report_zones(struct gendisk *disk, sector_t sector,
146 unsigned int nr_zones,
147 struct blk_report_zones_args *args);
148blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op,
149 sector_t sector, sector_t nr_sectors);
150size_t null_zone_valid_read_len(struct nullb *nullb,
151 sector_t sector, unsigned int len);
152ssize_t zone_cond_store(struct nullb_device *dev, const char *page,
153 size_t count, enum blk_zone_cond cond);
154#else
155static inline int null_init_zoned_dev(struct nullb_device *dev,
156 struct queue_limits *lim)
157{
158 pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
159 return -EINVAL;
160}
161static inline int null_register_zoned_dev(struct nullb *nullb)
162{
163 return -ENODEV;
164}
165static inline void null_free_zoned_dev(struct nullb_device *dev) {}
166static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
167 enum req_op op, sector_t sector, sector_t nr_sectors)
168{
169 return BLK_STS_NOTSUPP;
170}
171static inline size_t null_zone_valid_read_len(struct nullb *nullb,
172 sector_t sector,
173 unsigned int len)
174{
175 return len;
176}
177static inline ssize_t zone_cond_store(struct nullb_device *dev,
178 const char *page, size_t count,
179 enum blk_zone_cond cond)
180{
181 return -EOPNOTSUPP;
182}
183#define null_report_zones NULL
184#endif /* CONFIG_BLK_DEV_ZONED */
185#endif /* __NULL_BLK_H */
186

source code of linux/drivers/block/null_blk/null_blk.h