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
18 struct nullb_cmd {
19 union {
20 struct request *rq;
21 struct bio *bio;
22 };
23 unsigned int tag;
24 blk_status_t error;
25 bool fake_timeout;
26 struct nullb_queue *nq;
27 struct hrtimer timer;
28 };
29
30 struct nullb_queue {
31 unsigned long *tag_map;
32 wait_queue_head_t wait;
33 unsigned int queue_depth;
34 struct nullb_device *dev;
35 unsigned int requeue_selection;
36
37 struct list_head poll_list;
38 spinlock_t poll_lock;
39
40 struct nullb_cmd *cmds;
41 };
42
43 struct nullb_zone {
44 /*
45 * Zone lock to prevent concurrent modification of a zone write
46 * pointer position and condition: with memory backing, a write
47 * command execution may sleep on memory allocation. For this case,
48 * use mutex as the zone lock. Otherwise, use the spinlock for
49 * locking the zone.
50 */
51 union {
52 spinlock_t spinlock;
53 struct mutex mutex;
54 };
55 enum blk_zone_type type;
56 enum blk_zone_cond cond;
57 sector_t start;
58 sector_t wp;
59 unsigned int len;
60 unsigned int capacity;
61 };
62
63 /* Queue modes */
64 enum {
65 NULL_Q_BIO = 0,
66 NULL_Q_RQ = 1,
67 NULL_Q_MQ = 2,
68 };
69
70 struct nullb_device {
71 struct nullb *nullb;
72 struct config_group group;
73 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
74 struct fault_config timeout_config;
75 struct fault_config requeue_config;
76 struct fault_config init_hctx_fault_config;
77 #endif
78 struct radix_tree_root data; /* data stored in the disk */
79 struct radix_tree_root cache; /* disk cache data */
80 unsigned long flags; /* device flags */
81 unsigned int curr_cache;
82 struct badblocks badblocks;
83
84 unsigned int nr_zones;
85 unsigned int nr_zones_imp_open;
86 unsigned int nr_zones_exp_open;
87 unsigned int nr_zones_closed;
88 unsigned int imp_close_zone_no;
89 struct nullb_zone *zones;
90 sector_t zone_size_sects;
91 bool need_zone_res_mgmt;
92 spinlock_t zone_res_lock;
93
94 unsigned long size; /* device size in MB */
95 unsigned long completion_nsec; /* time in ns to complete a request */
96 unsigned long cache_size; /* disk cache size in MB */
97 unsigned long zone_size; /* zone size in MB if device is zoned */
98 unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
99 unsigned int zone_nr_conv; /* number of conventional zones */
100 unsigned int zone_max_open; /* max number of open zones */
101 unsigned int zone_max_active; /* max number of active zones */
102 unsigned int submit_queues; /* number of submission queues */
103 unsigned int prev_submit_queues; /* number of submission queues before change */
104 unsigned int poll_queues; /* number of IOPOLL submission queues */
105 unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */
106 unsigned int home_node; /* home node for the device */
107 unsigned int queue_mode; /* block interface */
108 unsigned int blocksize; /* block size */
109 unsigned int max_sectors; /* Max sectors per command */
110 unsigned int irqmode; /* IRQ completion handler */
111 unsigned int hw_queue_depth; /* queue depth */
112 unsigned int index; /* index of the disk, only valid with a disk */
113 unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
114 bool blocking; /* blocking blk-mq device */
115 bool use_per_node_hctx; /* use per-node allocation for hardware context */
116 bool power; /* power on/off the device */
117 bool memory_backed; /* if data is stored in memory */
118 bool discard; /* if support discard */
119 bool zoned; /* if device is zoned */
120 bool virt_boundary; /* virtual boundary on/off for the device */
121 bool no_sched; /* no IO scheduler for the device */
122 bool shared_tag_bitmap; /* use hostwide shared tags */
123 };
124
125 struct nullb {
126 struct nullb_device *dev;
127 struct list_head list;
128 unsigned int index;
129 struct request_queue *q;
130 struct gendisk *disk;
131 struct blk_mq_tag_set *tag_set;
132 struct blk_mq_tag_set __tag_set;
133 unsigned int queue_depth;
134 atomic_long_t cur_bytes;
135 struct hrtimer bw_timer;
136 unsigned long cache_flush_pos;
137 spinlock_t lock;
138
139 struct nullb_queue *queues;
140 unsigned int nr_queues;
141 char disk_name[DISK_NAME_LEN];
142 };
143
144 blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
145 sector_t nr_sectors);
146 blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op,
147 sector_t sector, unsigned int nr_sectors);
148
149 #ifdef CONFIG_BLK_DEV_ZONED
150 int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
151 int null_register_zoned_dev(struct nullb *nullb);
152 void null_free_zoned_dev(struct nullb_device *dev);
153 int null_report_zones(struct gendisk *disk, sector_t sector,
154 unsigned int nr_zones, report_zones_cb cb, void *data);
155 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op,
156 sector_t sector, sector_t nr_sectors);
157 size_t null_zone_valid_read_len(struct nullb *nullb,
158 sector_t sector, unsigned int len);
159 ssize_t zone_cond_store(struct nullb_device *dev, const char *page,
160 size_t count, enum blk_zone_cond cond);
161 #else
null_init_zoned_dev(struct nullb_device * dev,struct request_queue * q)162 static inline int null_init_zoned_dev(struct nullb_device *dev,
163 struct request_queue *q)
164 {
165 pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
166 return -EINVAL;
167 }
null_register_zoned_dev(struct nullb * nullb)168 static inline int null_register_zoned_dev(struct nullb *nullb)
169 {
170 return -ENODEV;
171 }
null_free_zoned_dev(struct nullb_device * dev)172 static inline void null_free_zoned_dev(struct nullb_device *dev) {}
null_process_zoned_cmd(struct nullb_cmd * cmd,enum req_op op,sector_t sector,sector_t nr_sectors)173 static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
174 enum req_op op, sector_t sector, sector_t nr_sectors)
175 {
176 return BLK_STS_NOTSUPP;
177 }
null_zone_valid_read_len(struct nullb * nullb,sector_t sector,unsigned int len)178 static inline size_t null_zone_valid_read_len(struct nullb *nullb,
179 sector_t sector,
180 unsigned int len)
181 {
182 return len;
183 }
zone_cond_store(struct nullb_device * dev,const char * page,size_t count,enum blk_zone_cond cond)184 static inline ssize_t zone_cond_store(struct nullb_device *dev,
185 const char *page, size_t count,
186 enum blk_zone_cond cond)
187 {
188 return -EOPNOTSUPP;
189 }
190 #define null_report_zones NULL
191 #endif /* CONFIG_BLK_DEV_ZONED */
192 #endif /* __NULL_BLK_H */
193