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fd0928df JA |
1 | #ifndef IOCONTEXT_H |
2 | #define IOCONTEXT_H | |
3 | ||
4ac845a2 | 4 | #include <linux/radix-tree.h> |
34e6bbf2 | 5 | #include <linux/rcupdate.h> |
4ac845a2 | 6 | |
fd0928df JA |
7 | /* |
8 | * This is the per-process anticipatory I/O scheduler state. | |
9 | */ | |
10 | struct as_io_context { | |
11 | spinlock_t lock; | |
12 | ||
13 | void (*dtor)(struct as_io_context *aic); /* destructor */ | |
14 | void (*exit)(struct as_io_context *aic); /* called on task exit */ | |
15 | ||
16 | unsigned long state; | |
17 | atomic_t nr_queued; /* queued reads & sync writes */ | |
18 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ | |
19 | ||
20 | /* IO History tracking */ | |
21 | /* Thinktime */ | |
22 | unsigned long last_end_request; | |
23 | unsigned long ttime_total; | |
24 | unsigned long ttime_samples; | |
25 | unsigned long ttime_mean; | |
26 | /* Layout pattern */ | |
27 | unsigned int seek_samples; | |
28 | sector_t last_request_pos; | |
29 | u64 seek_total; | |
30 | sector_t seek_mean; | |
31 | }; | |
32 | ||
33 | struct cfq_queue; | |
34 | struct cfq_io_context { | |
fd0928df | 35 | void *key; |
4ac845a2 | 36 | unsigned long dead_key; |
fd0928df JA |
37 | |
38 | struct cfq_queue *cfqq[2]; | |
39 | ||
40 | struct io_context *ioc; | |
41 | ||
42 | unsigned long last_end_request; | |
fd0928df JA |
43 | |
44 | unsigned long ttime_total; | |
45 | unsigned long ttime_samples; | |
46 | unsigned long ttime_mean; | |
47 | ||
fd0928df | 48 | struct list_head queue_list; |
ffc4e759 | 49 | struct hlist_node cic_list; |
fd0928df JA |
50 | |
51 | void (*dtor)(struct io_context *); /* destructor */ | |
52 | void (*exit)(struct io_context *); /* called on task exit */ | |
34e6bbf2 FC |
53 | |
54 | struct rcu_head rcu_head; | |
fd0928df JA |
55 | }; |
56 | ||
57 | /* | |
d38ecf93 JA |
58 | * I/O subsystem state of the associated processes. It is refcounted |
59 | * and kmalloc'ed. These could be shared between processes. | |
fd0928df JA |
60 | */ |
61 | struct io_context { | |
d9c7d394 | 62 | atomic_long_t refcount; |
d38ecf93 JA |
63 | atomic_t nr_tasks; |
64 | ||
65 | /* all the fields below are protected by this lock */ | |
66 | spinlock_t lock; | |
fd0928df JA |
67 | |
68 | unsigned short ioprio; | |
69 | unsigned short ioprio_changed; | |
70 | ||
31e4c28d VG |
71 | #ifdef CONFIG_BLK_CGROUP |
72 | unsigned short cgroup_changed; | |
73 | #endif | |
74 | ||
fd0928df JA |
75 | /* |
76 | * For request batching | |
77 | */ | |
78 | unsigned long last_waited; /* Time last woken after wait for request */ | |
79 | int nr_batch_requests; /* Number of requests left in the batch */ | |
80 | ||
81 | struct as_io_context *aic; | |
4ac845a2 | 82 | struct radix_tree_root radix_root; |
ffc4e759 | 83 | struct hlist_head cic_list; |
fd0928df JA |
84 | void *ioc_data; |
85 | }; | |
86 | ||
d38ecf93 JA |
87 | static inline struct io_context *ioc_task_link(struct io_context *ioc) |
88 | { | |
89 | /* | |
90 | * if ref count is zero, don't allow sharing (ioc is going away, it's | |
91 | * a race). | |
92 | */ | |
d9c7d394 | 93 | if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) { |
cbb4f264 | 94 | atomic_inc(&ioc->nr_tasks); |
d38ecf93 | 95 | return ioc; |
d237e5c7 | 96 | } |
d38ecf93 JA |
97 | |
98 | return NULL; | |
99 | } | |
100 | ||
b69f2292 | 101 | struct task_struct; |
da9cbc87 JA |
102 | #ifdef CONFIG_BLOCK |
103 | int put_io_context(struct io_context *ioc); | |
b69f2292 | 104 | void exit_io_context(struct task_struct *task); |
da9cbc87 JA |
105 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
106 | struct io_context *alloc_io_context(gfp_t gfp_flags, int node); | |
107 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); | |
108 | #else | |
b69f2292 | 109 | static inline void exit_io_context(struct task_struct *task) |
da9cbc87 JA |
110 | { |
111 | } | |
112 | ||
113 | struct io_context; | |
114 | static inline int put_io_context(struct io_context *ioc) | |
115 | { | |
116 | return 1; | |
117 | } | |
118 | #endif | |
119 | ||
fd0928df | 120 | #endif |