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(fbc: &rwstat->cpu_cnt[i]); |
17 | return ret; |
18 | } |
19 | atomic64_set(v: &rwstat->aux_cnt[i], 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(fbc: &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(blkg: 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(m: sf, fmt: "%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(m: sf, fmt: "%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(rwstat: (void *)pd + off, result: &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 | memset(sum, 0, sizeof(*sum)); |
113 | rcu_read_lock(); |
114 | blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { |
115 | struct blkg_rwstat *rwstat; |
116 | |
117 | if (!pos_blkg->online) |
118 | continue; |
119 | |
120 | if (pol) |
121 | rwstat = (void *)blkg_to_pd(blkg: pos_blkg, pol) + off; |
122 | else |
123 | rwstat = (void *)pos_blkg + off; |
124 | |
125 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
126 | sum->cnt[i] += blkg_rwstat_read_counter(rwstat, idx: i); |
127 | } |
128 | rcu_read_unlock(); |
129 | } |
130 | EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum); |
131 | |