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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 | struct cfq_queue; |
8 | struct cfq_io_context { | |
fd0928df | 9 | void *key; |
4ac845a2 | 10 | unsigned long dead_key; |
fd0928df JA |
11 | |
12 | struct cfq_queue *cfqq[2]; | |
13 | ||
14 | struct io_context *ioc; | |
15 | ||
16 | unsigned long last_end_request; | |
fd0928df JA |
17 | |
18 | unsigned long ttime_total; | |
19 | unsigned long ttime_samples; | |
20 | unsigned long ttime_mean; | |
21 | ||
fd0928df | 22 | struct list_head queue_list; |
ffc4e759 | 23 | struct hlist_node cic_list; |
fd0928df JA |
24 | |
25 | void (*dtor)(struct io_context *); /* destructor */ | |
26 | void (*exit)(struct io_context *); /* called on task exit */ | |
34e6bbf2 FC |
27 | |
28 | struct rcu_head rcu_head; | |
fd0928df JA |
29 | }; |
30 | ||
31 | /* | |
d38ecf93 JA |
32 | * I/O subsystem state of the associated processes. It is refcounted |
33 | * and kmalloc'ed. These could be shared between processes. | |
fd0928df JA |
34 | */ |
35 | struct io_context { | |
d9c7d394 | 36 | atomic_long_t refcount; |
d38ecf93 JA |
37 | atomic_t nr_tasks; |
38 | ||
39 | /* all the fields below are protected by this lock */ | |
40 | spinlock_t lock; | |
fd0928df JA |
41 | |
42 | unsigned short ioprio; | |
43 | unsigned short ioprio_changed; | |
44 | ||
67523c48 | 45 | #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE) |
31e4c28d VG |
46 | unsigned short cgroup_changed; |
47 | #endif | |
48 | ||
fd0928df JA |
49 | /* |
50 | * For request batching | |
51 | */ | |
fd0928df | 52 | int nr_batch_requests; /* Number of requests left in the batch */ |
58c24a61 | 53 | unsigned long last_waited; /* Time last woken after wait for request */ |
fd0928df | 54 | |
4ac845a2 | 55 | struct radix_tree_root radix_root; |
ffc4e759 | 56 | struct hlist_head cic_list; |
fd0928df JA |
57 | void *ioc_data; |
58 | }; | |
59 | ||
d38ecf93 JA |
60 | static inline struct io_context *ioc_task_link(struct io_context *ioc) |
61 | { | |
62 | /* | |
63 | * if ref count is zero, don't allow sharing (ioc is going away, it's | |
64 | * a race). | |
65 | */ | |
d9c7d394 | 66 | if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) { |
cbb4f264 | 67 | atomic_inc(&ioc->nr_tasks); |
d38ecf93 | 68 | return ioc; |
d237e5c7 | 69 | } |
d38ecf93 JA |
70 | |
71 | return NULL; | |
72 | } | |
73 | ||
b69f2292 | 74 | struct task_struct; |
da9cbc87 JA |
75 | #ifdef CONFIG_BLOCK |
76 | int put_io_context(struct io_context *ioc); | |
b69f2292 | 77 | void exit_io_context(struct task_struct *task); |
da9cbc87 JA |
78 | struct io_context *get_io_context(gfp_t gfp_flags, int node); |
79 | struct io_context *alloc_io_context(gfp_t gfp_flags, int node); | |
80 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); | |
81 | #else | |
b69f2292 | 82 | static inline void exit_io_context(struct task_struct *task) |
da9cbc87 JA |
83 | { |
84 | } | |
85 | ||
86 | struct io_context; | |
87 | static inline int put_io_context(struct io_context *ioc) | |
88 | { | |
89 | return 1; | |
90 | } | |
91 | #endif | |
92 | ||
fd0928df | 93 | #endif |