1 /* 2 * Internal header file _only_ for device mapper core 3 * 4 * Copyright (C) 2016 Red Hat, Inc. All rights reserved. 5 * 6 * This file is released under the LGPL. 7 */ 8 9 #ifndef DM_CORE_INTERNAL_H 10 #define DM_CORE_INTERNAL_H 11 12 #include <linux/kthread.h> 13 #include <linux/ktime.h> 14 #include <linux/blk-mq.h> 15 16 #include <trace/events/block.h> 17 18 #include "dm.h" 19 20 #define DM_RESERVED_MAX_IOS 1024 21 22 struct dm_kobject_holder { 23 struct kobject kobj; 24 struct completion completion; 25 }; 26 27 /* 28 * DM core internal structure that used directly by dm.c and dm-rq.c 29 * DM targets must _not_ deference a mapped_device to directly access its members! 30 */ 31 struct mapped_device { 32 struct mutex suspend_lock; 33 34 struct mutex table_devices_lock; 35 struct list_head table_devices; 36 37 /* 38 * The current mapping (struct dm_table *). 39 * Use dm_get_live_table{_fast} or take suspend_lock for 40 * dereference. 41 */ 42 void __rcu *map; 43 44 unsigned long flags; 45 46 /* Protect queue and type against concurrent access. */ 47 struct mutex type_lock; 48 enum dm_queue_mode type; 49 50 int numa_node_id; 51 struct request_queue *queue; 52 53 atomic_t holders; 54 atomic_t open_count; 55 56 struct dm_target *immutable_target; 57 struct target_type *immutable_target_type; 58 59 char name[16]; 60 struct gendisk *disk; 61 struct dax_device *dax_dev; 62 63 /* 64 * A list of ios that arrived while we were suspended. 65 */ 66 struct work_struct work; 67 wait_queue_head_t wait; 68 atomic_t pending[2]; 69 spinlock_t deferred_lock; 70 struct bio_list deferred; 71 72 void *interface_ptr; 73 74 /* 75 * Event handling. 76 */ 77 wait_queue_head_t eventq; 78 atomic_t event_nr; 79 atomic_t uevent_seq; 80 struct list_head uevent_list; 81 spinlock_t uevent_lock; /* Protect access to uevent_list */ 82 83 /* the number of internal suspends */ 84 unsigned internal_suspend_count; 85 86 /* 87 * io objects are allocated from here. 88 */ 89 struct bio_set io_bs; 90 struct bio_set bs; 91 92 /* 93 * Processing queue (flush) 94 */ 95 struct workqueue_struct *wq; 96 97 /* 98 * freeze/thaw support require holding onto a super block 99 */ 100 struct super_block *frozen_sb; 101 102 /* forced geometry settings */ 103 struct hd_geometry geometry; 104 105 /* kobject and completion */ 106 struct dm_kobject_holder kobj_holder; 107 108 struct block_device *bdev; 109 110 /* zero-length flush that will be cloned and submitted to targets */ 111 struct bio flush_bio; 112 113 struct dm_stats stats; 114 115 /* for blk-mq request-based DM support */ 116 struct blk_mq_tag_set *tag_set; 117 bool init_tio_pdu:1; 118 119 struct srcu_struct io_barrier; 120 }; 121 122 int md_in_flight(struct mapped_device *md); 123 void disable_write_same(struct mapped_device *md); 124 void disable_write_zeroes(struct mapped_device *md); 125 126 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) 127 { 128 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; 129 } 130 131 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max); 132 133 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) 134 { 135 return !maxlen || strlen(result) + 1 >= maxlen; 136 } 137 138 extern atomic_t dm_global_event_nr; 139 extern wait_queue_head_t dm_global_eventq; 140 void dm_issue_global_event(void); 141 142 #endif 143