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 blk_status_t error;
20 bool fake_timeout;
21 struct nullb_queue *nq;
22 struct hrtimer timer;
23 };
24
25 struct 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
33 struct 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
53 struct 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
67 unsigned int nr_zones;
68 unsigned int nr_zones_imp_open;
69 unsigned int nr_zones_exp_open;
70 unsigned int nr_zones_closed;
71 unsigned int imp_close_zone_no;
72 struct nullb_zone *zones;
73 sector_t zone_size_sects;
74 bool need_zone_res_mgmt;
75 spinlock_t zone_res_lock;
76
77 unsigned long size; /* device size in MB */
78 unsigned long completion_nsec; /* time in ns to complete a request */
79 unsigned long cache_size; /* disk cache size in MB */
80 unsigned long zone_size; /* zone size in MB if device is zoned */
81 unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
82 unsigned int zone_nr_conv; /* number of conventional zones */
83 unsigned int zone_max_open; /* max number of open zones */
84 unsigned int zone_max_active; /* max number of active zones */
85 unsigned int zone_append_max_sectors; /* Max sectors per zone append command */
86 unsigned int submit_queues; /* number of submission queues */
87 unsigned int prev_submit_queues; /* number of submission queues before change */
88 unsigned int poll_queues; /* number of IOPOLL submission queues */
89 unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */
90 unsigned int home_node; /* home node for the device */
91 unsigned int queue_mode; /* block interface */
92 unsigned int blocksize; /* block size */
93 unsigned int max_sectors; /* Max sectors per command */
94 unsigned int irqmode; /* IRQ completion handler */
95 unsigned int hw_queue_depth; /* queue depth */
96 unsigned int index; /* index of the disk, only valid with a disk */
97 unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
98 bool blocking; /* blocking blk-mq device */
99 bool use_per_node_hctx; /* use per-node allocation for hardware context */
100 bool power; /* power on/off the device */
101 bool memory_backed; /* if data is stored in memory */
102 bool discard; /* if support discard */
103 bool zoned; /* if device is zoned */
104 bool zone_full; /* Initialize zones to be full */
105 bool virt_boundary; /* virtual boundary on/off for the device */
106 bool no_sched; /* no IO scheduler for the device */
107 bool shared_tags; /* share tag set between devices for blk-mq */
108 bool shared_tag_bitmap; /* use hostwide shared tags */
109 bool fua; /* Support FUA */
110 };
111
112 struct nullb {
113 struct nullb_device *dev;
114 struct list_head list;
115 unsigned int index;
116 struct request_queue *q;
117 struct gendisk *disk;
118 struct blk_mq_tag_set *tag_set;
119 struct blk_mq_tag_set __tag_set;
120 atomic_long_t cur_bytes;
121 struct hrtimer bw_timer;
122 unsigned long cache_flush_pos;
123 spinlock_t lock;
124
125 struct nullb_queue *queues;
126 char disk_name[DISK_NAME_LEN];
127 };
128
129 blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
130 sector_t nr_sectors);
131 blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op,
132 sector_t sector, unsigned int nr_sectors);
133
134 #ifdef CONFIG_BLK_DEV_ZONED
135 int null_init_zoned_dev(struct nullb_device *dev, struct queue_limits *lim);
136 int null_register_zoned_dev(struct nullb *nullb);
137 void null_free_zoned_dev(struct nullb_device *dev);
138 int null_report_zones(struct gendisk *disk, sector_t sector,
139 unsigned int nr_zones, report_zones_cb cb, void *data);
140 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op,
141 sector_t sector, sector_t nr_sectors);
142 size_t null_zone_valid_read_len(struct nullb *nullb,
143 sector_t sector, unsigned int len);
144 ssize_t zone_cond_store(struct nullb_device *dev, const char *page,
145 size_t count, enum blk_zone_cond cond);
146 #else
null_init_zoned_dev(struct nullb_device * dev,struct queue_limits * lim)147 static inline int null_init_zoned_dev(struct nullb_device *dev,
148 struct queue_limits *lim)
149 {
150 pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
151 return -EINVAL;
152 }
null_register_zoned_dev(struct nullb * nullb)153 static inline int null_register_zoned_dev(struct nullb *nullb)
154 {
155 return -ENODEV;
156 }
null_free_zoned_dev(struct nullb_device * dev)157 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)158 static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
159 enum req_op op, sector_t sector, sector_t nr_sectors)
160 {
161 return BLK_STS_NOTSUPP;
162 }
null_zone_valid_read_len(struct nullb * nullb,sector_t sector,unsigned int len)163 static inline size_t null_zone_valid_read_len(struct nullb *nullb,
164 sector_t sector,
165 unsigned int len)
166 {
167 return len;
168 }
zone_cond_store(struct nullb_device * dev,const char * page,size_t count,enum blk_zone_cond cond)169 static inline ssize_t zone_cond_store(struct nullb_device *dev,
170 const char *page, size_t count,
171 enum blk_zone_cond cond)
172 {
173 return -EOPNOTSUPP;
174 }
175 #define null_report_zones NULL
176 #endif /* CONFIG_BLK_DEV_ZONED */
177 #endif /* __NULL_BLK_H */
178