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1 | /* SPDX-License-Identifier: GPL-2.0 | |
2 | * | |
3 | * Legacy blkg rwstat helpers enabled by CONFIG_BLK_CGROUP_RWSTAT. | |
4 | * Do not use in new code. | |
5 | */ | |
6 | #include "blk-cgroup-rwstat.h" | |
7 | ||
8 | int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp) | |
9 | { | |
10 | int i, ret; | |
11 | ||
12 | for (i = 0; i < BLKG_RWSTAT_NR; i++) { | |
13 | ret = percpu_counter_init(&rwstat->cpu_cnt[i], 0, gfp); | |
14 | if (ret) { | |
15 | while (--i >= 0) | |
16 | percpu_counter_destroy(&rwstat->cpu_cnt[i]); | |
17 | return ret; | |
18 | } | |
19 | atomic64_set(&rwstat->aux_cnt[i], 0); | |
20 | } | |
21 | return 0; | |
22 | } | |
23 | EXPORT_SYMBOL_GPL(blkg_rwstat_init); | |
24 | ||
25 | void blkg_rwstat_exit(struct blkg_rwstat *rwstat) | |
26 | { | |
27 | int i; | |
28 | ||
29 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
30 | percpu_counter_destroy(&rwstat->cpu_cnt[i]); | |
31 | } | |
32 | EXPORT_SYMBOL_GPL(blkg_rwstat_exit); | |
33 | ||
34 | /** | |
35 | * __blkg_prfill_rwstat - prfill helper for a blkg_rwstat | |
36 | * @sf: seq_file to print to | |
37 | * @pd: policy private data of interest | |
38 | * @rwstat: rwstat to print | |
39 | * | |
40 | * Print @rwstat to @sf for the device assocaited with @pd. | |
41 | */ | |
42 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
43 | const struct blkg_rwstat_sample *rwstat) | |
44 | { | |
45 | static const char *rwstr[] = { | |
46 | [BLKG_RWSTAT_READ] = "Read", | |
47 | [BLKG_RWSTAT_WRITE] = "Write", | |
48 | [BLKG_RWSTAT_SYNC] = "Sync", | |
49 | [BLKG_RWSTAT_ASYNC] = "Async", | |
50 | [BLKG_RWSTAT_DISCARD] = "Discard", | |
51 | }; | |
52 | const char *dname = blkg_dev_name(pd->blkg); | |
53 | u64 v; | |
54 | int i; | |
55 | ||
56 | if (!dname) | |
57 | return 0; | |
58 | ||
59 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
60 | seq_printf(sf, "%s %s %llu\n", dname, rwstr[i], | |
61 | rwstat->cnt[i]); | |
62 | ||
63 | v = rwstat->cnt[BLKG_RWSTAT_READ] + | |
64 | rwstat->cnt[BLKG_RWSTAT_WRITE] + | |
65 | rwstat->cnt[BLKG_RWSTAT_DISCARD]; | |
66 | seq_printf(sf, "%s Total %llu\n", dname, v); | |
67 | return v; | |
68 | } | |
69 | EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat); | |
70 | ||
71 | /** | |
72 | * blkg_prfill_rwstat - prfill callback for blkg_rwstat | |
73 | * @sf: seq_file to print to | |
74 | * @pd: policy private data of interest | |
75 | * @off: offset to the blkg_rwstat in @pd | |
76 | * | |
77 | * prfill callback for printing a blkg_rwstat. | |
78 | */ | |
79 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, | |
80 | int off) | |
81 | { | |
82 | struct blkg_rwstat_sample rwstat = { }; | |
83 | ||
84 | blkg_rwstat_read((void *)pd + off, &rwstat); | |
85 | return __blkg_prfill_rwstat(sf, pd, &rwstat); | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); | |
88 | ||
89 | /** | |
90 | * blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat | |
91 | * @blkg: blkg of interest | |
92 | * @pol: blkcg_policy which contains the blkg_rwstat | |
93 | * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg | |
94 | * @sum: blkg_rwstat_sample structure containing the results | |
95 | * | |
96 | * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its | |
97 | * online descendants and their aux counts. The caller must be holding the | |
98 | * queue lock for online tests. | |
99 | * | |
100 | * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it | |
101 | * is at @off bytes into @blkg's blkg_policy_data of the policy. | |
102 | */ | |
103 | void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, | |
104 | int off, struct blkg_rwstat_sample *sum) | |
105 | { | |
106 | struct blkcg_gq *pos_blkg; | |
107 | struct cgroup_subsys_state *pos_css; | |
108 | unsigned int i; | |
109 | ||
110 | lockdep_assert_held(&blkg->q->queue_lock); | |
111 | ||
112 | rcu_read_lock(); | |
113 | blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { | |
114 | struct blkg_rwstat *rwstat; | |
115 | ||
116 | if (!pos_blkg->online) | |
117 | continue; | |
118 | ||
119 | if (pol) | |
120 | rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off; | |
121 | else | |
122 | rwstat = (void *)pos_blkg + off; | |
123 | ||
124 | for (i = 0; i < BLKG_RWSTAT_NR; i++) | |
125 | sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i); | |
126 | } | |
127 | rcu_read_unlock(); | |
128 | } | |
129 | EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum); |