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07e4fead OS |
1 | /* |
2 | * Copyright (C) 2017 Facebook | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program. If not, see <https://www.gnu.org/licenses/>. | |
15 | */ | |
16 | ||
17 | #include <linux/kernel.h> | |
18 | #include <linux/blkdev.h> | |
19 | #include <linux/debugfs.h> | |
20 | ||
21 | #include <linux/blk-mq.h> | |
22 | #include "blk-mq.h" | |
23 | ||
24 | struct blk_mq_debugfs_attr { | |
25 | const char *name; | |
26 | umode_t mode; | |
27 | const struct file_operations *fops; | |
28 | }; | |
29 | ||
30 | static struct dentry *block_debugfs_root; | |
31 | ||
32 | static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { | |
33 | }; | |
34 | ||
35 | static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { | |
36 | }; | |
37 | ||
38 | int blk_mq_debugfs_register(struct request_queue *q, const char *name) | |
39 | { | |
40 | if (!block_debugfs_root) | |
41 | return -ENOENT; | |
42 | ||
43 | q->debugfs_dir = debugfs_create_dir(name, block_debugfs_root); | |
44 | if (!q->debugfs_dir) | |
45 | goto err; | |
46 | ||
47 | if (blk_mq_debugfs_register_hctxs(q)) | |
48 | goto err; | |
49 | ||
50 | return 0; | |
51 | ||
52 | err: | |
53 | blk_mq_debugfs_unregister(q); | |
54 | return -ENOMEM; | |
55 | } | |
56 | ||
57 | void blk_mq_debugfs_unregister(struct request_queue *q) | |
58 | { | |
59 | debugfs_remove_recursive(q->debugfs_dir); | |
60 | q->mq_debugfs_dir = NULL; | |
61 | q->debugfs_dir = NULL; | |
62 | } | |
63 | ||
64 | static int blk_mq_debugfs_register_ctx(struct request_queue *q, | |
65 | struct blk_mq_ctx *ctx, | |
66 | struct dentry *hctx_dir) | |
67 | { | |
68 | struct dentry *ctx_dir; | |
69 | char name[20]; | |
70 | int i; | |
71 | ||
72 | snprintf(name, sizeof(name), "cpu%u", ctx->cpu); | |
73 | ctx_dir = debugfs_create_dir(name, hctx_dir); | |
74 | if (!ctx_dir) | |
75 | return -ENOMEM; | |
76 | ||
77 | for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_ctx_attrs); i++) { | |
78 | const struct blk_mq_debugfs_attr *attr; | |
79 | ||
80 | attr = &blk_mq_debugfs_ctx_attrs[i]; | |
81 | if (!debugfs_create_file(attr->name, attr->mode, ctx_dir, ctx, | |
82 | attr->fops)) | |
83 | return -ENOMEM; | |
84 | } | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | static int blk_mq_debugfs_register_hctx(struct request_queue *q, | |
90 | struct blk_mq_hw_ctx *hctx) | |
91 | { | |
92 | struct blk_mq_ctx *ctx; | |
93 | struct dentry *hctx_dir; | |
94 | char name[20]; | |
95 | int i; | |
96 | ||
97 | snprintf(name, sizeof(name), "%u", hctx->queue_num); | |
98 | hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir); | |
99 | if (!hctx_dir) | |
100 | return -ENOMEM; | |
101 | ||
102 | for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_hctx_attrs); i++) { | |
103 | const struct blk_mq_debugfs_attr *attr; | |
104 | ||
105 | attr = &blk_mq_debugfs_hctx_attrs[i]; | |
106 | if (!debugfs_create_file(attr->name, attr->mode, hctx_dir, hctx, | |
107 | attr->fops)) | |
108 | return -ENOMEM; | |
109 | } | |
110 | ||
111 | hctx_for_each_ctx(hctx, ctx, i) { | |
112 | if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir)) | |
113 | return -ENOMEM; | |
114 | } | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | int blk_mq_debugfs_register_hctxs(struct request_queue *q) | |
120 | { | |
121 | struct blk_mq_hw_ctx *hctx; | |
122 | int i; | |
123 | ||
124 | if (!q->debugfs_dir) | |
125 | return -ENOENT; | |
126 | ||
127 | q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir); | |
128 | if (!q->mq_debugfs_dir) | |
129 | goto err; | |
130 | ||
131 | queue_for_each_hw_ctx(q, hctx, i) { | |
132 | if (blk_mq_debugfs_register_hctx(q, hctx)) | |
133 | goto err; | |
134 | } | |
135 | ||
136 | return 0; | |
137 | ||
138 | err: | |
139 | blk_mq_debugfs_unregister_hctxs(q); | |
140 | return -ENOMEM; | |
141 | } | |
142 | ||
143 | void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) | |
144 | { | |
145 | debugfs_remove_recursive(q->mq_debugfs_dir); | |
146 | q->mq_debugfs_dir = NULL; | |
147 | } | |
148 | ||
149 | void blk_mq_debugfs_init(void) | |
150 | { | |
151 | block_debugfs_root = debugfs_create_dir("block", NULL); | |
152 | } |