Tejun Heo | 1d156646 | 2019-11-07 11:18:04 -0800 | [diff] [blame] | 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 | |
Kefeng Wang | 688c8b9 | 2024-03-25 11:59:55 +0800 | [diff] [blame] | 12 | ret = percpu_counter_init_many(rwstat->cpu_cnt, 0, gfp, BLKG_RWSTAT_NR); |
| 13 | if (ret) |
| 14 | return ret; |
| 15 | |
| 16 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
Tejun Heo | 1d156646 | 2019-11-07 11:18:04 -0800 | [diff] [blame] | 17 | atomic64_set(&rwstat->aux_cnt[i], 0); |
Tejun Heo | 1d156646 | 2019-11-07 11:18:04 -0800 | [diff] [blame] | 18 | return 0; |
| 19 | } |
| 20 | EXPORT_SYMBOL_GPL(blkg_rwstat_init); |
| 21 | |
| 22 | void blkg_rwstat_exit(struct blkg_rwstat *rwstat) |
| 23 | { |
Kefeng Wang | 688c8b9 | 2024-03-25 11:59:55 +0800 | [diff] [blame] | 24 | percpu_counter_destroy_many(rwstat->cpu_cnt, BLKG_RWSTAT_NR); |
Tejun Heo | 1d156646 | 2019-11-07 11:18:04 -0800 | [diff] [blame] | 25 | } |
| 26 | EXPORT_SYMBOL_GPL(blkg_rwstat_exit); |
| 27 | |
| 28 | /** |
| 29 | * __blkg_prfill_rwstat - prfill helper for a blkg_rwstat |
| 30 | * @sf: seq_file to print to |
| 31 | * @pd: policy private data of interest |
| 32 | * @rwstat: rwstat to print |
| 33 | * |
| 34 | * Print @rwstat to @sf for the device assocaited with @pd. |
| 35 | */ |
| 36 | u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, |
| 37 | const struct blkg_rwstat_sample *rwstat) |
| 38 | { |
| 39 | static const char *rwstr[] = { |
| 40 | [BLKG_RWSTAT_READ] = "Read", |
| 41 | [BLKG_RWSTAT_WRITE] = "Write", |
| 42 | [BLKG_RWSTAT_SYNC] = "Sync", |
| 43 | [BLKG_RWSTAT_ASYNC] = "Async", |
| 44 | [BLKG_RWSTAT_DISCARD] = "Discard", |
| 45 | }; |
| 46 | const char *dname = blkg_dev_name(pd->blkg); |
| 47 | u64 v; |
| 48 | int i; |
| 49 | |
| 50 | if (!dname) |
| 51 | return 0; |
| 52 | |
| 53 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
| 54 | seq_printf(sf, "%s %s %llu\n", dname, rwstr[i], |
| 55 | rwstat->cnt[i]); |
| 56 | |
| 57 | v = rwstat->cnt[BLKG_RWSTAT_READ] + |
| 58 | rwstat->cnt[BLKG_RWSTAT_WRITE] + |
| 59 | rwstat->cnt[BLKG_RWSTAT_DISCARD]; |
| 60 | seq_printf(sf, "%s Total %llu\n", dname, v); |
| 61 | return v; |
| 62 | } |
| 63 | EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat); |
| 64 | |
| 65 | /** |
| 66 | * blkg_prfill_rwstat - prfill callback for blkg_rwstat |
| 67 | * @sf: seq_file to print to |
| 68 | * @pd: policy private data of interest |
| 69 | * @off: offset to the blkg_rwstat in @pd |
| 70 | * |
| 71 | * prfill callback for printing a blkg_rwstat. |
| 72 | */ |
| 73 | u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, |
| 74 | int off) |
| 75 | { |
| 76 | struct blkg_rwstat_sample rwstat = { }; |
| 77 | |
| 78 | blkg_rwstat_read((void *)pd + off, &rwstat); |
| 79 | return __blkg_prfill_rwstat(sf, pd, &rwstat); |
| 80 | } |
| 81 | EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); |
| 82 | |
| 83 | /** |
| 84 | * blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat |
| 85 | * @blkg: blkg of interest |
| 86 | * @pol: blkcg_policy which contains the blkg_rwstat |
| 87 | * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg |
| 88 | * @sum: blkg_rwstat_sample structure containing the results |
| 89 | * |
| 90 | * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its |
| 91 | * online descendants and their aux counts. The caller must be holding the |
| 92 | * queue lock for online tests. |
| 93 | * |
| 94 | * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it |
| 95 | * is at @off bytes into @blkg's blkg_policy_data of the policy. |
| 96 | */ |
| 97 | void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, |
| 98 | int off, struct blkg_rwstat_sample *sum) |
| 99 | { |
| 100 | struct blkcg_gq *pos_blkg; |
| 101 | struct cgroup_subsys_state *pos_css; |
| 102 | unsigned int i; |
| 103 | |
| 104 | lockdep_assert_held(&blkg->q->queue_lock); |
| 105 | |
Xunlei Pang | 4f44657 | 2021-03-05 16:13:27 +0800 | [diff] [blame] | 106 | memset(sum, 0, sizeof(*sum)); |
Tejun Heo | 1d156646 | 2019-11-07 11:18:04 -0800 | [diff] [blame] | 107 | rcu_read_lock(); |
| 108 | blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { |
| 109 | struct blkg_rwstat *rwstat; |
| 110 | |
| 111 | if (!pos_blkg->online) |
| 112 | continue; |
| 113 | |
| 114 | if (pol) |
| 115 | rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off; |
| 116 | else |
| 117 | rwstat = (void *)pos_blkg + off; |
| 118 | |
| 119 | for (i = 0; i < BLKG_RWSTAT_NR; i++) |
Xunlei Pang | 4f44657 | 2021-03-05 16:13:27 +0800 | [diff] [blame] | 120 | sum->cnt[i] += blkg_rwstat_read_counter(rwstat, i); |
Tejun Heo | 1d156646 | 2019-11-07 11:18:04 -0800 | [diff] [blame] | 121 | } |
| 122 | rcu_read_unlock(); |
| 123 | } |
| 124 | EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum); |