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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 | /* * Internal header file _only_ for device mapper core * * Copyright (C) 2016 Red Hat, Inc. All rights reserved. * * This file is released under the LGPL. */ #ifndef DM_CORE_INTERNAL_H #define DM_CORE_INTERNAL_H #include <linux/kthread.h> #include <linux/ktime.h> #include <linux/blk-mq.h> #include <trace/events/block.h> #include "dm.h" #define DM_RESERVED_MAX_IOS 1024 struct dm_kobject_holder { struct kobject kobj; struct completion completion; }; /* * DM core internal structure that used directly by dm.c and dm-rq.c * DM targets must _not_ deference a mapped_device to directly access its members! */ struct mapped_device { struct srcu_struct io_barrier; struct mutex suspend_lock; /* * The current mapping (struct dm_table *). * Use dm_get_live_table{_fast} or take suspend_lock for * dereference. */ void __rcu *map; struct list_head table_devices; struct mutex table_devices_lock; unsigned long flags; struct request_queue *queue; int numa_node_id; unsigned type; /* Protect queue and type against concurrent access. */ struct mutex type_lock; atomic_t holders; atomic_t open_count; struct dm_target *immutable_target; struct target_type *immutable_target_type; struct gendisk *disk; char name[16]; void *interface_ptr; /* * A list of ios that arrived while we were suspended. */ atomic_t pending[2]; wait_queue_head_t wait; struct work_struct work; spinlock_t deferred_lock; struct bio_list deferred; /* * Event handling. */ wait_queue_head_t eventq; atomic_t event_nr; atomic_t uevent_seq; struct list_head uevent_list; spinlock_t uevent_lock; /* Protect access to uevent_list */ /* the number of internal suspends */ unsigned internal_suspend_count; /* * Processing queue (flush) */ struct workqueue_struct *wq; /* * io objects are allocated from here. */ mempool_t *io_pool; struct bio_set *bs; /* * freeze/thaw support require holding onto a super block */ struct super_block *frozen_sb; /* forced geometry settings */ struct hd_geometry geometry; struct block_device *bdev; /* kobject and completion */ struct dm_kobject_holder kobj_holder; /* zero-length flush that will be cloned and submitted to targets */ struct bio flush_bio; struct dm_stats stats; struct kthread_worker kworker; struct task_struct *kworker_task; /* for request-based merge heuristic in dm_request_fn() */ unsigned seq_rq_merge_deadline_usecs; int last_rq_rw; sector_t last_rq_pos; ktime_t last_rq_start_time; /* for blk-mq request-based DM support */ struct blk_mq_tag_set *tag_set; bool use_blk_mq:1; bool init_tio_pdu:1; }; void dm_init_md_queue(struct mapped_device *md); void dm_init_normal_md_queue(struct mapped_device *md); int md_in_flight(struct mapped_device *md); void disable_write_same(struct mapped_device *md); static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj) { return &container_of(kobj, struct dm_kobject_holder, kobj)->completion; } unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max); static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen) { return !maxlen || strlen(result) + 1 >= maxlen; } #endif |