Commit | Line | Data |
---|---|---|
2056a782 | 1 | /* |
0fe23479 | 2 | * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> |
2056a782 JA |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * 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 | |
11 | * GNU 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, write to the Free Software | |
15 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | * | |
17 | */ | |
2056a782 JA |
18 | #include <linux/kernel.h> |
19 | #include <linux/blkdev.h> | |
20 | #include <linux/blktrace_api.h> | |
21 | #include <linux/percpu.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/mutex.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
2056a782 | 25 | #include <linux/debugfs.h> |
6e5fdeed | 26 | #include <linux/export.h> |
be1c6341 | 27 | #include <linux/time.h> |
939b3669 | 28 | #include <linux/uaccess.h> |
a404d557 | 29 | #include <linux/list.h> |
ca1136c9 | 30 | #include <linux/blk-cgroup.h> |
55782138 | 31 | |
18fbda91 OS |
32 | #include "../../block/blk.h" |
33 | ||
55782138 LZ |
34 | #include <trace/events/block.h> |
35 | ||
2db270a8 | 36 | #include "trace_output.h" |
2056a782 | 37 | |
55782138 LZ |
38 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
39 | ||
2056a782 JA |
40 | static unsigned int blktrace_seq __read_mostly = 1; |
41 | ||
c71a8961 | 42 | static struct trace_array *blk_tr; |
5006ea73 | 43 | static bool blk_tracer_enabled __read_mostly; |
c71a8961 | 44 | |
a404d557 JK |
45 | static LIST_HEAD(running_trace_list); |
46 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(running_trace_lock); | |
47 | ||
c71a8961 | 48 | /* Select an alternative, minimalistic output than the original one */ |
ef18012b | 49 | #define TRACE_BLK_OPT_CLASSIC 0x1 |
ca1136c9 | 50 | #define TRACE_BLK_OPT_CGROUP 0x2 |
69fd5c39 | 51 | #define TRACE_BLK_OPT_CGNAME 0x4 |
c71a8961 ACM |
52 | |
53 | static struct tracer_opt blk_tracer_opts[] = { | |
54 | /* Default disable the minimalistic output */ | |
157f9c00 | 55 | { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, |
ca1136c9 SL |
56 | #ifdef CONFIG_BLK_CGROUP |
57 | { TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) }, | |
69fd5c39 | 58 | { TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) }, |
ca1136c9 | 59 | #endif |
c71a8961 ACM |
60 | { } |
61 | }; | |
62 | ||
63 | static struct tracer_flags blk_tracer_flags = { | |
64 | .val = 0, | |
65 | .opts = blk_tracer_opts, | |
66 | }; | |
67 | ||
5f3ea37c | 68 | /* Global reference count of probes */ |
5f3ea37c ACM |
69 | static atomic_t blk_probes_ref = ATOMIC_INIT(0); |
70 | ||
3c289ba7 | 71 | static void blk_register_tracepoints(void); |
5f3ea37c ACM |
72 | static void blk_unregister_tracepoints(void); |
73 | ||
be1c6341 OK |
74 | /* |
75 | * Send out a notify message. | |
76 | */ | |
a863055b | 77 | static void trace_note(struct blk_trace *bt, pid_t pid, int action, |
ca1136c9 SL |
78 | const void *data, size_t len, |
79 | union kernfs_node_id *cgid) | |
be1c6341 OK |
80 | { |
81 | struct blk_io_trace *t; | |
18cea459 | 82 | struct ring_buffer_event *event = NULL; |
e77405ad | 83 | struct ring_buffer *buffer = NULL; |
18cea459 LZ |
84 | int pc = 0; |
85 | int cpu = smp_processor_id(); | |
86 | bool blk_tracer = blk_tracer_enabled; | |
ca1136c9 | 87 | ssize_t cgid_len = cgid ? sizeof(*cgid) : 0; |
18cea459 LZ |
88 | |
89 | if (blk_tracer) { | |
12883efb | 90 | buffer = blk_tr->trace_buffer.buffer; |
18cea459 | 91 | pc = preempt_count(); |
e77405ad | 92 | event = trace_buffer_lock_reserve(buffer, TRACE_BLK, |
ca1136c9 | 93 | sizeof(*t) + len + cgid_len, |
18cea459 LZ |
94 | 0, pc); |
95 | if (!event) | |
96 | return; | |
97 | t = ring_buffer_event_data(event); | |
98 | goto record_it; | |
99 | } | |
be1c6341 | 100 | |
c71a8961 ACM |
101 | if (!bt->rchan) |
102 | return; | |
103 | ||
ca1136c9 | 104 | t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len); |
d3d9d2a5 | 105 | if (t) { |
d3d9d2a5 | 106 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; |
2997c8c4 | 107 | t->time = ktime_to_ns(ktime_get()); |
18cea459 | 108 | record_it: |
d3d9d2a5 | 109 | t->device = bt->dev; |
ca1136c9 | 110 | t->action = action | (cgid ? __BLK_TN_CGROUP : 0); |
d3d9d2a5 JA |
111 | t->pid = pid; |
112 | t->cpu = cpu; | |
ca1136c9 SL |
113 | t->pdu_len = len + cgid_len; |
114 | if (cgid) | |
115 | memcpy((void *)t + sizeof(*t), cgid, cgid_len); | |
116 | memcpy((void *) t + sizeof(*t) + cgid_len, data, len); | |
18cea459 LZ |
117 | |
118 | if (blk_tracer) | |
b7f0c959 | 119 | trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc); |
d3d9d2a5 | 120 | } |
be1c6341 OK |
121 | } |
122 | ||
2056a782 JA |
123 | /* |
124 | * Send out a notify for this process, if we haven't done so since a trace | |
125 | * started | |
126 | */ | |
a404d557 | 127 | static void trace_note_tsk(struct task_struct *tsk) |
2056a782 | 128 | { |
a404d557 JK |
129 | unsigned long flags; |
130 | struct blk_trace *bt; | |
131 | ||
a863055b | 132 | tsk->btrace_seq = blktrace_seq; |
a404d557 JK |
133 | spin_lock_irqsave(&running_trace_lock, flags); |
134 | list_for_each_entry(bt, &running_trace_list, running_list) { | |
135 | trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, | |
ca1136c9 | 136 | sizeof(tsk->comm), NULL); |
a404d557 JK |
137 | } |
138 | spin_unlock_irqrestore(&running_trace_lock, flags); | |
be1c6341 | 139 | } |
2056a782 | 140 | |
be1c6341 OK |
141 | static void trace_note_time(struct blk_trace *bt) |
142 | { | |
59a37f8b | 143 | struct timespec64 now; |
be1c6341 OK |
144 | unsigned long flags; |
145 | u32 words[2]; | |
146 | ||
59a37f8b AB |
147 | /* need to check user space to see if this breaks in y2038 or y2106 */ |
148 | ktime_get_real_ts64(&now); | |
149 | words[0] = (u32)now.tv_sec; | |
be1c6341 OK |
150 | words[1] = now.tv_nsec; |
151 | ||
152 | local_irq_save(flags); | |
ca1136c9 | 153 | trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), NULL); |
be1c6341 | 154 | local_irq_restore(flags); |
2056a782 JA |
155 | } |
156 | ||
35fe6d76 SL |
157 | void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg, |
158 | const char *fmt, ...) | |
9d5f09a4 AB |
159 | { |
160 | int n; | |
161 | va_list args; | |
14a73f54 | 162 | unsigned long flags; |
64565911 | 163 | char *buf; |
9d5f09a4 | 164 | |
18cea459 LZ |
165 | if (unlikely(bt->trace_state != Blktrace_running && |
166 | !blk_tracer_enabled)) | |
c71a8961 ACM |
167 | return; |
168 | ||
490da40d TM |
169 | /* |
170 | * If the BLK_TC_NOTIFY action mask isn't set, don't send any note | |
171 | * message to the trace. | |
172 | */ | |
173 | if (!(bt->act_mask & BLK_TC_NOTIFY)) | |
174 | return; | |
175 | ||
14a73f54 | 176 | local_irq_save(flags); |
d8a0349c | 177 | buf = this_cpu_ptr(bt->msg_data); |
9d5f09a4 | 178 | va_start(args, fmt); |
64565911 | 179 | n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); |
9d5f09a4 AB |
180 | va_end(args); |
181 | ||
35fe6d76 SL |
182 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) |
183 | blkcg = NULL; | |
184 | #ifdef CONFIG_BLK_CGROUP | |
185 | trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, | |
186 | blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : NULL); | |
187 | #else | |
ca1136c9 | 188 | trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, NULL); |
35fe6d76 | 189 | #endif |
14a73f54 | 190 | local_irq_restore(flags); |
9d5f09a4 AB |
191 | } |
192 | EXPORT_SYMBOL_GPL(__trace_note_message); | |
193 | ||
2056a782 JA |
194 | static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, |
195 | pid_t pid) | |
196 | { | |
197 | if (((bt->act_mask << BLK_TC_SHIFT) & what) == 0) | |
198 | return 1; | |
d0deef5b | 199 | if (sector && (sector < bt->start_lba || sector > bt->end_lba)) |
2056a782 JA |
200 | return 1; |
201 | if (bt->pid && pid != bt->pid) | |
202 | return 1; | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Data direction bit lookup | |
209 | */ | |
e4955c99 LZ |
210 | static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ), |
211 | BLK_TC_ACT(BLK_TC_WRITE) }; | |
2056a782 | 212 | |
7b6d91da | 213 | #define BLK_TC_RAHEAD BLK_TC_AHEAD |
28a8f0d3 | 214 | #define BLK_TC_PREFLUSH BLK_TC_FLUSH |
7b6d91da | 215 | |
35ba8f70 | 216 | /* The ilog2() calls fall out because they're constant */ |
7b6d91da CH |
217 | #define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \ |
218 | (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## __name)) | |
2056a782 JA |
219 | |
220 | /* | |
221 | * The worker for the various blk_add_trace*() types. Fills out a | |
222 | * blk_io_trace structure and places it in a per-cpu subbuffer. | |
223 | */ | |
5f3ea37c | 224 | static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, |
1b9a9ab7 | 225 | int op, int op_flags, u32 what, int error, int pdu_len, |
ca1136c9 | 226 | void *pdu_data, union kernfs_node_id *cgid) |
2056a782 JA |
227 | { |
228 | struct task_struct *tsk = current; | |
c71a8961 | 229 | struct ring_buffer_event *event = NULL; |
e77405ad | 230 | struct ring_buffer *buffer = NULL; |
2056a782 | 231 | struct blk_io_trace *t; |
0a987751 | 232 | unsigned long flags = 0; |
2056a782 JA |
233 | unsigned long *sequence; |
234 | pid_t pid; | |
c71a8961 | 235 | int cpu, pc = 0; |
18cea459 | 236 | bool blk_tracer = blk_tracer_enabled; |
ca1136c9 | 237 | ssize_t cgid_len = cgid ? sizeof(*cgid) : 0; |
2056a782 | 238 | |
18cea459 | 239 | if (unlikely(bt->trace_state != Blktrace_running && !blk_tracer)) |
2056a782 JA |
240 | return; |
241 | ||
1b9a9ab7 MC |
242 | what |= ddir_act[op_is_write(op) ? WRITE : READ]; |
243 | what |= MASK_TC_BIT(op_flags, SYNC); | |
244 | what |= MASK_TC_BIT(op_flags, RAHEAD); | |
245 | what |= MASK_TC_BIT(op_flags, META); | |
28a8f0d3 | 246 | what |= MASK_TC_BIT(op_flags, PREFLUSH); |
1b9a9ab7 | 247 | what |= MASK_TC_BIT(op_flags, FUA); |
7afafc8a | 248 | if (op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE) |
1b9a9ab7 | 249 | what |= BLK_TC_ACT(BLK_TC_DISCARD); |
3a5e02ce MC |
250 | if (op == REQ_OP_FLUSH) |
251 | what |= BLK_TC_ACT(BLK_TC_FLUSH); | |
ca1136c9 SL |
252 | if (cgid) |
253 | what |= __BLK_TA_CGROUP; | |
2056a782 JA |
254 | |
255 | pid = tsk->pid; | |
d0deef5b | 256 | if (act_log_check(bt, what, sector, pid)) |
2056a782 | 257 | return; |
c71a8961 ACM |
258 | cpu = raw_smp_processor_id(); |
259 | ||
18cea459 | 260 | if (blk_tracer) { |
c71a8961 ACM |
261 | tracing_record_cmdline(current); |
262 | ||
12883efb | 263 | buffer = blk_tr->trace_buffer.buffer; |
51a763dd | 264 | pc = preempt_count(); |
e77405ad | 265 | event = trace_buffer_lock_reserve(buffer, TRACE_BLK, |
ca1136c9 | 266 | sizeof(*t) + pdu_len + cgid_len, |
51a763dd | 267 | 0, pc); |
c71a8961 ACM |
268 | if (!event) |
269 | return; | |
51a763dd | 270 | t = ring_buffer_event_data(event); |
c71a8961 ACM |
271 | goto record_it; |
272 | } | |
2056a782 | 273 | |
a404d557 JK |
274 | if (unlikely(tsk->btrace_seq != blktrace_seq)) |
275 | trace_note_tsk(tsk); | |
276 | ||
2056a782 JA |
277 | /* |
278 | * A word about the locking here - we disable interrupts to reserve | |
279 | * some space in the relay per-cpu buffer, to prevent an irq | |
14a73f54 | 280 | * from coming in and stepping on our toes. |
2056a782 JA |
281 | */ |
282 | local_irq_save(flags); | |
ca1136c9 | 283 | t = relay_reserve(bt->rchan, sizeof(*t) + pdu_len + cgid_len); |
2056a782 | 284 | if (t) { |
2056a782 JA |
285 | sequence = per_cpu_ptr(bt->sequence, cpu); |
286 | ||
287 | t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; | |
288 | t->sequence = ++(*sequence); | |
2997c8c4 | 289 | t->time = ktime_to_ns(ktime_get()); |
c71a8961 | 290 | record_it: |
08a06b83 | 291 | /* |
939b3669 ACM |
292 | * These two are not needed in ftrace as they are in the |
293 | * generic trace_entry, filled by tracing_generic_entry_update, | |
294 | * but for the trace_event->bin() synthesizer benefit we do it | |
295 | * here too. | |
296 | */ | |
297 | t->cpu = cpu; | |
298 | t->pid = pid; | |
08a06b83 | 299 | |
2056a782 JA |
300 | t->sector = sector; |
301 | t->bytes = bytes; | |
302 | t->action = what; | |
2056a782 | 303 | t->device = bt->dev; |
2056a782 | 304 | t->error = error; |
ca1136c9 | 305 | t->pdu_len = pdu_len + cgid_len; |
2056a782 | 306 | |
ca1136c9 SL |
307 | if (cgid_len) |
308 | memcpy((void *)t + sizeof(*t), cgid, cgid_len); | |
2056a782 | 309 | if (pdu_len) |
ca1136c9 | 310 | memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len); |
c71a8961 | 311 | |
18cea459 | 312 | if (blk_tracer) { |
b7f0c959 | 313 | trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc); |
c71a8961 ACM |
314 | return; |
315 | } | |
2056a782 JA |
316 | } |
317 | ||
318 | local_irq_restore(flags); | |
319 | } | |
320 | ||
ad5dd549 | 321 | static void blk_trace_free(struct blk_trace *bt) |
2056a782 | 322 | { |
02c62304 | 323 | debugfs_remove(bt->msg_file); |
2056a782 | 324 | debugfs_remove(bt->dropped_file); |
f48fc4d3 | 325 | relay_close(bt->rchan); |
39cbb602 | 326 | debugfs_remove(bt->dir); |
2056a782 | 327 | free_percpu(bt->sequence); |
64565911 | 328 | free_percpu(bt->msg_data); |
2056a782 | 329 | kfree(bt); |
ad5dd549 LZ |
330 | } |
331 | ||
332 | static void blk_trace_cleanup(struct blk_trace *bt) | |
333 | { | |
334 | blk_trace_free(bt); | |
5f3ea37c ACM |
335 | if (atomic_dec_and_test(&blk_probes_ref)) |
336 | blk_unregister_tracepoints(); | |
2056a782 JA |
337 | } |
338 | ||
6da127ad | 339 | int blk_trace_remove(struct request_queue *q) |
2056a782 JA |
340 | { |
341 | struct blk_trace *bt; | |
342 | ||
343 | bt = xchg(&q->blk_trace, NULL); | |
344 | if (!bt) | |
345 | return -EINVAL; | |
346 | ||
55547204 | 347 | if (bt->trace_state != Blktrace_running) |
2056a782 JA |
348 | blk_trace_cleanup(bt); |
349 | ||
350 | return 0; | |
351 | } | |
6da127ad | 352 | EXPORT_SYMBOL_GPL(blk_trace_remove); |
2056a782 | 353 | |
2056a782 JA |
354 | static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, |
355 | size_t count, loff_t *ppos) | |
356 | { | |
357 | struct blk_trace *bt = filp->private_data; | |
358 | char buf[16]; | |
359 | ||
360 | snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped)); | |
361 | ||
362 | return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf)); | |
363 | } | |
364 | ||
2b8693c0 | 365 | static const struct file_operations blk_dropped_fops = { |
2056a782 | 366 | .owner = THIS_MODULE, |
234e3405 | 367 | .open = simple_open, |
2056a782 | 368 | .read = blk_dropped_read, |
6038f373 | 369 | .llseek = default_llseek, |
2056a782 JA |
370 | }; |
371 | ||
02c62304 AB |
372 | static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, |
373 | size_t count, loff_t *ppos) | |
374 | { | |
375 | char *msg; | |
376 | struct blk_trace *bt; | |
377 | ||
7635b03a | 378 | if (count >= BLK_TN_MAX_MSG) |
02c62304 AB |
379 | return -EINVAL; |
380 | ||
16e5c1fc AV |
381 | msg = memdup_user_nul(buffer, count); |
382 | if (IS_ERR(msg)) | |
383 | return PTR_ERR(msg); | |
02c62304 | 384 | |
02c62304 | 385 | bt = filp->private_data; |
35fe6d76 | 386 | __trace_note_message(bt, NULL, "%s", msg); |
02c62304 AB |
387 | kfree(msg); |
388 | ||
389 | return count; | |
390 | } | |
391 | ||
392 | static const struct file_operations blk_msg_fops = { | |
393 | .owner = THIS_MODULE, | |
234e3405 | 394 | .open = simple_open, |
02c62304 | 395 | .write = blk_msg_write, |
6038f373 | 396 | .llseek = noop_llseek, |
02c62304 AB |
397 | }; |
398 | ||
2056a782 JA |
399 | /* |
400 | * Keep track of how many times we encountered a full subbuffer, to aid | |
401 | * the user space app in telling how many lost events there were. | |
402 | */ | |
403 | static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, | |
404 | void *prev_subbuf, size_t prev_padding) | |
405 | { | |
406 | struct blk_trace *bt; | |
407 | ||
408 | if (!relay_buf_full(buf)) | |
409 | return 1; | |
410 | ||
411 | bt = buf->chan->private_data; | |
412 | atomic_inc(&bt->dropped); | |
413 | return 0; | |
414 | } | |
415 | ||
416 | static int blk_remove_buf_file_callback(struct dentry *dentry) | |
417 | { | |
418 | debugfs_remove(dentry); | |
f48fc4d3 | 419 | |
2056a782 JA |
420 | return 0; |
421 | } | |
422 | ||
423 | static struct dentry *blk_create_buf_file_callback(const char *filename, | |
424 | struct dentry *parent, | |
f4ae40a6 | 425 | umode_t mode, |
2056a782 JA |
426 | struct rchan_buf *buf, |
427 | int *is_global) | |
428 | { | |
429 | return debugfs_create_file(filename, mode, parent, buf, | |
430 | &relay_file_operations); | |
431 | } | |
432 | ||
433 | static struct rchan_callbacks blk_relay_callbacks = { | |
434 | .subbuf_start = blk_subbuf_start_callback, | |
435 | .create_buf_file = blk_create_buf_file_callback, | |
436 | .remove_buf_file = blk_remove_buf_file_callback, | |
437 | }; | |
438 | ||
9908c309 LZ |
439 | static void blk_trace_setup_lba(struct blk_trace *bt, |
440 | struct block_device *bdev) | |
441 | { | |
442 | struct hd_struct *part = NULL; | |
443 | ||
444 | if (bdev) | |
445 | part = bdev->bd_part; | |
446 | ||
447 | if (part) { | |
448 | bt->start_lba = part->start_sect; | |
449 | bt->end_lba = part->start_sect + part->nr_sects; | |
450 | } else { | |
451 | bt->start_lba = 0; | |
452 | bt->end_lba = -1ULL; | |
453 | } | |
454 | } | |
455 | ||
2056a782 JA |
456 | /* |
457 | * Setup everything required to start tracing | |
458 | */ | |
a428d314 OS |
459 | static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
460 | struct block_device *bdev, | |
461 | struct blk_user_trace_setup *buts) | |
2056a782 | 462 | { |
cdea01b2 | 463 | struct blk_trace *bt = NULL; |
2056a782 | 464 | struct dentry *dir = NULL; |
ff14417c | 465 | int ret; |
2056a782 | 466 | |
171044d4 | 467 | if (!buts->buf_size || !buts->buf_nr) |
2056a782 JA |
468 | return -EINVAL; |
469 | ||
0497b345 JA |
470 | strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); |
471 | buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; | |
2056a782 JA |
472 | |
473 | /* | |
474 | * some device names have larger paths - convert the slashes | |
475 | * to underscores for this to work as expected | |
476 | */ | |
ff14417c | 477 | strreplace(buts->name, '/', '_'); |
2056a782 | 478 | |
2056a782 JA |
479 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
480 | if (!bt) | |
ad5dd549 | 481 | return -ENOMEM; |
2056a782 | 482 | |
ad5dd549 | 483 | ret = -ENOMEM; |
2056a782 JA |
484 | bt->sequence = alloc_percpu(unsigned long); |
485 | if (!bt->sequence) | |
486 | goto err; | |
487 | ||
313e458f | 488 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
64565911 JA |
489 | if (!bt->msg_data) |
490 | goto err; | |
491 | ||
2056a782 | 492 | ret = -ENOENT; |
f48fc4d3 | 493 | |
18fbda91 OS |
494 | if (!blk_debugfs_root) |
495 | goto err; | |
f48fc4d3 | 496 | |
6ac93117 OS |
497 | dir = debugfs_lookup(buts->name, blk_debugfs_root); |
498 | if (!dir) | |
499 | bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root); | |
2056a782 JA |
500 | if (!dir) |
501 | goto err; | |
502 | ||
6da127ad | 503 | bt->dev = dev; |
2056a782 | 504 | atomic_set(&bt->dropped, 0); |
a404d557 | 505 | INIT_LIST_HEAD(&bt->running_list); |
2056a782 JA |
506 | |
507 | ret = -EIO; | |
939b3669 ACM |
508 | bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, |
509 | &blk_dropped_fops); | |
2056a782 JA |
510 | if (!bt->dropped_file) |
511 | goto err; | |
512 | ||
02c62304 AB |
513 | bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); |
514 | if (!bt->msg_file) | |
515 | goto err; | |
516 | ||
171044d4 AB |
517 | bt->rchan = relay_open("trace", dir, buts->buf_size, |
518 | buts->buf_nr, &blk_relay_callbacks, bt); | |
2056a782 JA |
519 | if (!bt->rchan) |
520 | goto err; | |
2056a782 | 521 | |
171044d4 | 522 | bt->act_mask = buts->act_mask; |
2056a782 JA |
523 | if (!bt->act_mask) |
524 | bt->act_mask = (u16) -1; | |
525 | ||
9908c309 | 526 | blk_trace_setup_lba(bt, bdev); |
2056a782 | 527 | |
d0deef5b SD |
528 | /* overwrite with user settings */ |
529 | if (buts->start_lba) | |
530 | bt->start_lba = buts->start_lba; | |
531 | if (buts->end_lba) | |
532 | bt->end_lba = buts->end_lba; | |
533 | ||
171044d4 | 534 | bt->pid = buts->pid; |
2056a782 JA |
535 | bt->trace_state = Blktrace_setup; |
536 | ||
537 | ret = -EBUSY; | |
cdea01b2 | 538 | if (cmpxchg(&q->blk_trace, NULL, bt)) |
2056a782 | 539 | goto err; |
2056a782 | 540 | |
17ba97e3 | 541 | if (atomic_inc_return(&blk_probes_ref) == 1) |
cbe28296 LZ |
542 | blk_register_tracepoints(); |
543 | ||
6ac93117 | 544 | ret = 0; |
2056a782 | 545 | err: |
6ac93117 OS |
546 | if (dir && !bt->dir) |
547 | dput(dir); | |
548 | if (ret) | |
549 | blk_trace_free(bt); | |
2056a782 JA |
550 | return ret; |
551 | } | |
171044d4 | 552 | |
6da127ad | 553 | int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, |
d0deef5b | 554 | struct block_device *bdev, |
6da127ad | 555 | char __user *arg) |
171044d4 AB |
556 | { |
557 | struct blk_user_trace_setup buts; | |
558 | int ret; | |
559 | ||
560 | ret = copy_from_user(&buts, arg, sizeof(buts)); | |
561 | if (ret) | |
562 | return -EFAULT; | |
563 | ||
d0deef5b | 564 | ret = do_blk_trace_setup(q, name, dev, bdev, &buts); |
171044d4 AB |
565 | if (ret) |
566 | return ret; | |
567 | ||
9a8c28c8 DM |
568 | if (copy_to_user(arg, &buts, sizeof(buts))) { |
569 | blk_trace_remove(q); | |
171044d4 | 570 | return -EFAULT; |
9a8c28c8 | 571 | } |
171044d4 AB |
572 | return 0; |
573 | } | |
6da127ad | 574 | EXPORT_SYMBOL_GPL(blk_trace_setup); |
2056a782 | 575 | |
62c2a7d9 AB |
576 | #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64) |
577 | static int compat_blk_trace_setup(struct request_queue *q, char *name, | |
578 | dev_t dev, struct block_device *bdev, | |
579 | char __user *arg) | |
580 | { | |
581 | struct blk_user_trace_setup buts; | |
582 | struct compat_blk_user_trace_setup cbuts; | |
583 | int ret; | |
584 | ||
585 | if (copy_from_user(&cbuts, arg, sizeof(cbuts))) | |
586 | return -EFAULT; | |
587 | ||
588 | buts = (struct blk_user_trace_setup) { | |
589 | .act_mask = cbuts.act_mask, | |
590 | .buf_size = cbuts.buf_size, | |
591 | .buf_nr = cbuts.buf_nr, | |
592 | .start_lba = cbuts.start_lba, | |
593 | .end_lba = cbuts.end_lba, | |
594 | .pid = cbuts.pid, | |
595 | }; | |
62c2a7d9 AB |
596 | |
597 | ret = do_blk_trace_setup(q, name, dev, bdev, &buts); | |
598 | if (ret) | |
599 | return ret; | |
600 | ||
f8c5e944 | 601 | if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) { |
62c2a7d9 AB |
602 | blk_trace_remove(q); |
603 | return -EFAULT; | |
604 | } | |
605 | ||
606 | return 0; | |
607 | } | |
608 | #endif | |
609 | ||
6da127ad | 610 | int blk_trace_startstop(struct request_queue *q, int start) |
2056a782 | 611 | { |
2056a782 | 612 | int ret; |
939b3669 | 613 | struct blk_trace *bt = q->blk_trace; |
2056a782 | 614 | |
939b3669 | 615 | if (bt == NULL) |
2056a782 JA |
616 | return -EINVAL; |
617 | ||
618 | /* | |
619 | * For starting a trace, we can transition from a setup or stopped | |
620 | * trace. For stopping a trace, the state must be running | |
621 | */ | |
622 | ret = -EINVAL; | |
623 | if (start) { | |
624 | if (bt->trace_state == Blktrace_setup || | |
625 | bt->trace_state == Blktrace_stopped) { | |
626 | blktrace_seq++; | |
627 | smp_mb(); | |
628 | bt->trace_state = Blktrace_running; | |
a404d557 JK |
629 | spin_lock_irq(&running_trace_lock); |
630 | list_add(&bt->running_list, &running_trace_list); | |
631 | spin_unlock_irq(&running_trace_lock); | |
be1c6341 OK |
632 | |
633 | trace_note_time(bt); | |
2056a782 JA |
634 | ret = 0; |
635 | } | |
636 | } else { | |
637 | if (bt->trace_state == Blktrace_running) { | |
638 | bt->trace_state = Blktrace_stopped; | |
a404d557 JK |
639 | spin_lock_irq(&running_trace_lock); |
640 | list_del_init(&bt->running_list); | |
641 | spin_unlock_irq(&running_trace_lock); | |
2056a782 JA |
642 | relay_flush(bt->rchan); |
643 | ret = 0; | |
644 | } | |
645 | } | |
646 | ||
647 | return ret; | |
648 | } | |
6da127ad | 649 | EXPORT_SYMBOL_GPL(blk_trace_startstop); |
2056a782 | 650 | |
5acb3cc2 WL |
651 | /* |
652 | * When reading or writing the blktrace sysfs files, the references to the | |
653 | * opened sysfs or device files should prevent the underlying block device | |
654 | * from being removed. So no further delete protection is really needed. | |
655 | */ | |
656 | ||
2056a782 JA |
657 | /** |
658 | * blk_trace_ioctl: - handle the ioctls associated with tracing | |
659 | * @bdev: the block device | |
ef18012b | 660 | * @cmd: the ioctl cmd |
2056a782 JA |
661 | * @arg: the argument data, if any |
662 | * | |
663 | **/ | |
664 | int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) | |
665 | { | |
165125e1 | 666 | struct request_queue *q; |
2056a782 | 667 | int ret, start = 0; |
6da127ad | 668 | char b[BDEVNAME_SIZE]; |
2056a782 JA |
669 | |
670 | q = bdev_get_queue(bdev); | |
671 | if (!q) | |
672 | return -ENXIO; | |
673 | ||
5acb3cc2 | 674 | mutex_lock(&q->blk_trace_mutex); |
2056a782 JA |
675 | |
676 | switch (cmd) { | |
677 | case BLKTRACESETUP: | |
f36f21ec | 678 | bdevname(bdev, b); |
d0deef5b | 679 | ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); |
2056a782 | 680 | break; |
62c2a7d9 AB |
681 | #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64) |
682 | case BLKTRACESETUP32: | |
683 | bdevname(bdev, b); | |
684 | ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); | |
685 | break; | |
686 | #endif | |
2056a782 JA |
687 | case BLKTRACESTART: |
688 | start = 1; | |
689 | case BLKTRACESTOP: | |
690 | ret = blk_trace_startstop(q, start); | |
691 | break; | |
692 | case BLKTRACETEARDOWN: | |
693 | ret = blk_trace_remove(q); | |
694 | break; | |
695 | default: | |
696 | ret = -ENOTTY; | |
697 | break; | |
698 | } | |
699 | ||
5acb3cc2 | 700 | mutex_unlock(&q->blk_trace_mutex); |
2056a782 JA |
701 | return ret; |
702 | } | |
703 | ||
704 | /** | |
705 | * blk_trace_shutdown: - stop and cleanup trace structures | |
706 | * @q: the request queue associated with the device | |
707 | * | |
708 | **/ | |
165125e1 | 709 | void blk_trace_shutdown(struct request_queue *q) |
2056a782 | 710 | { |
6c5c9341 AD |
711 | if (q->blk_trace) { |
712 | blk_trace_startstop(q, 0); | |
713 | blk_trace_remove(q); | |
714 | } | |
2056a782 | 715 | } |
5f3ea37c | 716 | |
ca1136c9 SL |
717 | #ifdef CONFIG_BLK_CGROUP |
718 | static union kernfs_node_id * | |
719 | blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) | |
720 | { | |
721 | struct blk_trace *bt = q->blk_trace; | |
722 | ||
723 | if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) | |
724 | return NULL; | |
725 | ||
726 | if (!bio->bi_css) | |
727 | return NULL; | |
728 | return cgroup_get_kernfs_id(bio->bi_css->cgroup); | |
729 | } | |
730 | #else | |
731 | static union kernfs_node_id * | |
732 | blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) | |
733 | { | |
734 | return NULL; | |
735 | } | |
736 | #endif | |
737 | ||
738 | static union kernfs_node_id * | |
739 | blk_trace_request_get_cgid(struct request_queue *q, struct request *rq) | |
740 | { | |
741 | if (!rq->bio) | |
742 | return NULL; | |
743 | /* Use the first bio */ | |
744 | return blk_trace_bio_get_cgid(q, rq->bio); | |
745 | } | |
746 | ||
5f3ea37c ACM |
747 | /* |
748 | * blktrace probes | |
749 | */ | |
750 | ||
751 | /** | |
752 | * blk_add_trace_rq - Add a trace for a request oriented action | |
5f3ea37c | 753 | * @rq: the source request |
caf7df12 | 754 | * @error: return status to log |
af5040da | 755 | * @nr_bytes: number of completed bytes |
5f3ea37c | 756 | * @what: the action |
ca1136c9 | 757 | * @cgid: the cgroup info |
5f3ea37c ACM |
758 | * |
759 | * Description: | |
760 | * Records an action against a request. Will log the bio offset + size. | |
761 | * | |
762 | **/ | |
caf7df12 | 763 | static void blk_add_trace_rq(struct request *rq, int error, |
ca1136c9 SL |
764 | unsigned int nr_bytes, u32 what, |
765 | union kernfs_node_id *cgid) | |
5f3ea37c | 766 | { |
caf7df12 | 767 | struct blk_trace *bt = rq->q->blk_trace; |
5f3ea37c ACM |
768 | |
769 | if (likely(!bt)) | |
770 | return; | |
771 | ||
57292b58 | 772 | if (blk_rq_is_passthrough(rq)) |
5f3ea37c | 773 | what |= BLK_TC_ACT(BLK_TC_PC); |
48b77ad6 | 774 | else |
5f3ea37c | 775 | what |= BLK_TC_ACT(BLK_TC_FS); |
48b77ad6 CH |
776 | |
777 | __blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq), | |
ca1136c9 | 778 | rq->cmd_flags, what, error, 0, NULL, cgid); |
5f3ea37c ACM |
779 | } |
780 | ||
38516ab5 SR |
781 | static void blk_add_trace_rq_insert(void *ignore, |
782 | struct request_queue *q, struct request *rq) | |
5f3ea37c | 783 | { |
ca1136c9 SL |
784 | blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT, |
785 | blk_trace_request_get_cgid(q, rq)); | |
5f3ea37c ACM |
786 | } |
787 | ||
38516ab5 SR |
788 | static void blk_add_trace_rq_issue(void *ignore, |
789 | struct request_queue *q, struct request *rq) | |
5f3ea37c | 790 | { |
ca1136c9 SL |
791 | blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE, |
792 | blk_trace_request_get_cgid(q, rq)); | |
5f3ea37c ACM |
793 | } |
794 | ||
38516ab5 SR |
795 | static void blk_add_trace_rq_requeue(void *ignore, |
796 | struct request_queue *q, | |
939b3669 | 797 | struct request *rq) |
5f3ea37c | 798 | { |
ca1136c9 SL |
799 | blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE, |
800 | blk_trace_request_get_cgid(q, rq)); | |
5f3ea37c ACM |
801 | } |
802 | ||
caf7df12 CH |
803 | static void blk_add_trace_rq_complete(void *ignore, struct request *rq, |
804 | int error, unsigned int nr_bytes) | |
5f3ea37c | 805 | { |
ca1136c9 SL |
806 | blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE, |
807 | blk_trace_request_get_cgid(rq->q, rq)); | |
5f3ea37c ACM |
808 | } |
809 | ||
810 | /** | |
811 | * blk_add_trace_bio - Add a trace for a bio oriented action | |
812 | * @q: queue the io is for | |
813 | * @bio: the source bio | |
814 | * @what: the action | |
797a455d | 815 | * @error: error, if any |
5f3ea37c ACM |
816 | * |
817 | * Description: | |
818 | * Records an action against a bio. Will log the bio offset + size. | |
819 | * | |
820 | **/ | |
821 | static void blk_add_trace_bio(struct request_queue *q, struct bio *bio, | |
ca1136c9 | 822 | u32 what, int error, union kernfs_node_id *cgid) |
5f3ea37c ACM |
823 | { |
824 | struct blk_trace *bt = q->blk_trace; | |
825 | ||
826 | if (likely(!bt)) | |
827 | return; | |
828 | ||
4f024f37 | 829 | __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size, |
ca1136c9 | 830 | bio_op(bio), bio->bi_opf, what, error, 0, NULL, cgid); |
5f3ea37c ACM |
831 | } |
832 | ||
38516ab5 SR |
833 | static void blk_add_trace_bio_bounce(void *ignore, |
834 | struct request_queue *q, struct bio *bio) | |
5f3ea37c | 835 | { |
ca1136c9 SL |
836 | blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0, |
837 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
838 | } |
839 | ||
0a82a8d1 LT |
840 | static void blk_add_trace_bio_complete(void *ignore, |
841 | struct request_queue *q, struct bio *bio, | |
842 | int error) | |
5f3ea37c | 843 | { |
ca1136c9 SL |
844 | blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error, |
845 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
846 | } |
847 | ||
38516ab5 SR |
848 | static void blk_add_trace_bio_backmerge(void *ignore, |
849 | struct request_queue *q, | |
8c1cf6bb | 850 | struct request *rq, |
939b3669 | 851 | struct bio *bio) |
5f3ea37c | 852 | { |
ca1136c9 SL |
853 | blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0, |
854 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
855 | } |
856 | ||
38516ab5 SR |
857 | static void blk_add_trace_bio_frontmerge(void *ignore, |
858 | struct request_queue *q, | |
8c1cf6bb | 859 | struct request *rq, |
939b3669 | 860 | struct bio *bio) |
5f3ea37c | 861 | { |
ca1136c9 SL |
862 | blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0, |
863 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
864 | } |
865 | ||
38516ab5 SR |
866 | static void blk_add_trace_bio_queue(void *ignore, |
867 | struct request_queue *q, struct bio *bio) | |
5f3ea37c | 868 | { |
ca1136c9 SL |
869 | blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0, |
870 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
871 | } |
872 | ||
38516ab5 SR |
873 | static void blk_add_trace_getrq(void *ignore, |
874 | struct request_queue *q, | |
939b3669 | 875 | struct bio *bio, int rw) |
5f3ea37c ACM |
876 | { |
877 | if (bio) | |
ca1136c9 SL |
878 | blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0, |
879 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
880 | else { |
881 | struct blk_trace *bt = q->blk_trace; | |
882 | ||
883 | if (bt) | |
1b9a9ab7 | 884 | __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0, |
ca1136c9 | 885 | NULL, NULL); |
5f3ea37c ACM |
886 | } |
887 | } | |
888 | ||
889 | ||
38516ab5 SR |
890 | static void blk_add_trace_sleeprq(void *ignore, |
891 | struct request_queue *q, | |
939b3669 | 892 | struct bio *bio, int rw) |
5f3ea37c ACM |
893 | { |
894 | if (bio) | |
ca1136c9 SL |
895 | blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 0, |
896 | blk_trace_bio_get_cgid(q, bio)); | |
5f3ea37c ACM |
897 | else { |
898 | struct blk_trace *bt = q->blk_trace; | |
899 | ||
900 | if (bt) | |
1b9a9ab7 | 901 | __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_SLEEPRQ, |
ca1136c9 | 902 | 0, 0, NULL, NULL); |
5f3ea37c ACM |
903 | } |
904 | } | |
905 | ||
38516ab5 | 906 | static void blk_add_trace_plug(void *ignore, struct request_queue *q) |
5f3ea37c ACM |
907 | { |
908 | struct blk_trace *bt = q->blk_trace; | |
909 | ||
910 | if (bt) | |
ca1136c9 | 911 | __blk_add_trace(bt, 0, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL, NULL); |
5f3ea37c ACM |
912 | } |
913 | ||
49cac01e JA |
914 | static void blk_add_trace_unplug(void *ignore, struct request_queue *q, |
915 | unsigned int depth, bool explicit) | |
5f3ea37c ACM |
916 | { |
917 | struct blk_trace *bt = q->blk_trace; | |
918 | ||
919 | if (bt) { | |
94b5eb28 | 920 | __be64 rpdu = cpu_to_be64(depth); |
49cac01e | 921 | u32 what; |
5f3ea37c | 922 | |
49cac01e JA |
923 | if (explicit) |
924 | what = BLK_TA_UNPLUG_IO; | |
925 | else | |
926 | what = BLK_TA_UNPLUG_TIMER; | |
927 | ||
ca1136c9 | 928 | __blk_add_trace(bt, 0, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu, NULL); |
5f3ea37c ACM |
929 | } |
930 | } | |
931 | ||
38516ab5 SR |
932 | static void blk_add_trace_split(void *ignore, |
933 | struct request_queue *q, struct bio *bio, | |
5f3ea37c ACM |
934 | unsigned int pdu) |
935 | { | |
936 | struct blk_trace *bt = q->blk_trace; | |
937 | ||
938 | if (bt) { | |
939 | __be64 rpdu = cpu_to_be64(pdu); | |
940 | ||
4f024f37 | 941 | __blk_add_trace(bt, bio->bi_iter.bi_sector, |
1eff9d32 | 942 | bio->bi_iter.bi_size, bio_op(bio), bio->bi_opf, |
4e4cbee9 | 943 | BLK_TA_SPLIT, bio->bi_status, sizeof(rpdu), |
ca1136c9 | 944 | &rpdu, blk_trace_bio_get_cgid(q, bio)); |
5f3ea37c ACM |
945 | } |
946 | } | |
947 | ||
948 | /** | |
d07335e5 | 949 | * blk_add_trace_bio_remap - Add a trace for a bio-remap operation |
546cf44a | 950 | * @ignore: trace callback data parameter (not used) |
5f3ea37c ACM |
951 | * @q: queue the io is for |
952 | * @bio: the source bio | |
953 | * @dev: target device | |
a42aaa3b | 954 | * @from: source sector |
5f3ea37c ACM |
955 | * |
956 | * Description: | |
957 | * Device mapper or raid target sometimes need to split a bio because | |
958 | * it spans a stripe (or similar). Add a trace for that action. | |
959 | * | |
960 | **/ | |
d07335e5 MS |
961 | static void blk_add_trace_bio_remap(void *ignore, |
962 | struct request_queue *q, struct bio *bio, | |
963 | dev_t dev, sector_t from) | |
5f3ea37c ACM |
964 | { |
965 | struct blk_trace *bt = q->blk_trace; | |
966 | struct blk_io_trace_remap r; | |
967 | ||
968 | if (likely(!bt)) | |
969 | return; | |
970 | ||
a42aaa3b | 971 | r.device_from = cpu_to_be32(dev); |
74d46992 | 972 | r.device_to = cpu_to_be32(bio_dev(bio)); |
a42aaa3b | 973 | r.sector_from = cpu_to_be64(from); |
5f3ea37c | 974 | |
4f024f37 | 975 | __blk_add_trace(bt, bio->bi_iter.bi_sector, bio->bi_iter.bi_size, |
4e4cbee9 | 976 | bio_op(bio), bio->bi_opf, BLK_TA_REMAP, bio->bi_status, |
ca1136c9 | 977 | sizeof(r), &r, blk_trace_bio_get_cgid(q, bio)); |
5f3ea37c ACM |
978 | } |
979 | ||
b0da3f0d JN |
980 | /** |
981 | * blk_add_trace_rq_remap - Add a trace for a request-remap operation | |
546cf44a | 982 | * @ignore: trace callback data parameter (not used) |
b0da3f0d JN |
983 | * @q: queue the io is for |
984 | * @rq: the source request | |
985 | * @dev: target device | |
986 | * @from: source sector | |
987 | * | |
988 | * Description: | |
989 | * Device mapper remaps request to other devices. | |
990 | * Add a trace for that action. | |
991 | * | |
992 | **/ | |
38516ab5 SR |
993 | static void blk_add_trace_rq_remap(void *ignore, |
994 | struct request_queue *q, | |
b0da3f0d JN |
995 | struct request *rq, dev_t dev, |
996 | sector_t from) | |
997 | { | |
998 | struct blk_trace *bt = q->blk_trace; | |
999 | struct blk_io_trace_remap r; | |
1000 | ||
1001 | if (likely(!bt)) | |
1002 | return; | |
1003 | ||
1004 | r.device_from = cpu_to_be32(dev); | |
1005 | r.device_to = cpu_to_be32(disk_devt(rq->rq_disk)); | |
1006 | r.sector_from = cpu_to_be64(from); | |
1007 | ||
1008 | __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), | |
caf7df12 | 1009 | rq_data_dir(rq), 0, BLK_TA_REMAP, 0, |
ca1136c9 | 1010 | sizeof(r), &r, blk_trace_request_get_cgid(q, rq)); |
b0da3f0d JN |
1011 | } |
1012 | ||
5f3ea37c ACM |
1013 | /** |
1014 | * blk_add_driver_data - Add binary message with driver-specific data | |
1015 | * @q: queue the io is for | |
1016 | * @rq: io request | |
1017 | * @data: driver-specific data | |
1018 | * @len: length of driver-specific data | |
1019 | * | |
1020 | * Description: | |
1021 | * Some drivers might want to write driver-specific data per request. | |
1022 | * | |
1023 | **/ | |
1024 | void blk_add_driver_data(struct request_queue *q, | |
1025 | struct request *rq, | |
1026 | void *data, size_t len) | |
1027 | { | |
1028 | struct blk_trace *bt = q->blk_trace; | |
1029 | ||
1030 | if (likely(!bt)) | |
1031 | return; | |
1032 | ||
48b77ad6 | 1033 | __blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0, |
ca1136c9 SL |
1034 | BLK_TA_DRV_DATA, 0, len, data, |
1035 | blk_trace_request_get_cgid(q, rq)); | |
5f3ea37c ACM |
1036 | } |
1037 | EXPORT_SYMBOL_GPL(blk_add_driver_data); | |
1038 | ||
3c289ba7 | 1039 | static void blk_register_tracepoints(void) |
5f3ea37c ACM |
1040 | { |
1041 | int ret; | |
1042 | ||
38516ab5 | 1043 | ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL); |
5f3ea37c | 1044 | WARN_ON(ret); |
38516ab5 | 1045 | ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL); |
5f3ea37c | 1046 | WARN_ON(ret); |
38516ab5 | 1047 | ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL); |
5f3ea37c | 1048 | WARN_ON(ret); |
38516ab5 | 1049 | ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL); |
5f3ea37c | 1050 | WARN_ON(ret); |
38516ab5 | 1051 | ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL); |
5f3ea37c | 1052 | WARN_ON(ret); |
38516ab5 | 1053 | ret = register_trace_block_bio_complete(blk_add_trace_bio_complete, NULL); |
5f3ea37c | 1054 | WARN_ON(ret); |
38516ab5 | 1055 | ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL); |
5f3ea37c | 1056 | WARN_ON(ret); |
38516ab5 | 1057 | ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL); |
5f3ea37c | 1058 | WARN_ON(ret); |
38516ab5 | 1059 | ret = register_trace_block_bio_queue(blk_add_trace_bio_queue, NULL); |
5f3ea37c | 1060 | WARN_ON(ret); |
38516ab5 | 1061 | ret = register_trace_block_getrq(blk_add_trace_getrq, NULL); |
5f3ea37c | 1062 | WARN_ON(ret); |
38516ab5 | 1063 | ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL); |
5f3ea37c | 1064 | WARN_ON(ret); |
38516ab5 | 1065 | ret = register_trace_block_plug(blk_add_trace_plug, NULL); |
5f3ea37c | 1066 | WARN_ON(ret); |
49cac01e | 1067 | ret = register_trace_block_unplug(blk_add_trace_unplug, NULL); |
5f3ea37c | 1068 | WARN_ON(ret); |
38516ab5 | 1069 | ret = register_trace_block_split(blk_add_trace_split, NULL); |
5f3ea37c | 1070 | WARN_ON(ret); |
d07335e5 | 1071 | ret = register_trace_block_bio_remap(blk_add_trace_bio_remap, NULL); |
5f3ea37c | 1072 | WARN_ON(ret); |
38516ab5 | 1073 | ret = register_trace_block_rq_remap(blk_add_trace_rq_remap, NULL); |
b0da3f0d | 1074 | WARN_ON(ret); |
5f3ea37c ACM |
1075 | } |
1076 | ||
1077 | static void blk_unregister_tracepoints(void) | |
1078 | { | |
38516ab5 | 1079 | unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL); |
d07335e5 | 1080 | unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL); |
38516ab5 | 1081 | unregister_trace_block_split(blk_add_trace_split, NULL); |
49cac01e | 1082 | unregister_trace_block_unplug(blk_add_trace_unplug, NULL); |
38516ab5 SR |
1083 | unregister_trace_block_plug(blk_add_trace_plug, NULL); |
1084 | unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL); | |
1085 | unregister_trace_block_getrq(blk_add_trace_getrq, NULL); | |
1086 | unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL); | |
1087 | unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL); | |
1088 | unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge, NULL); | |
1089 | unregister_trace_block_bio_complete(blk_add_trace_bio_complete, NULL); | |
1090 | unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL); | |
1091 | unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL); | |
1092 | unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL); | |
1093 | unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL); | |
1094 | unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL); | |
5f3ea37c ACM |
1095 | |
1096 | tracepoint_synchronize_unregister(); | |
1097 | } | |
c71a8961 ACM |
1098 | |
1099 | /* | |
1100 | * struct blk_io_tracer formatting routines | |
1101 | */ | |
1102 | ||
1103 | static void fill_rwbs(char *rwbs, const struct blk_io_trace *t) | |
1104 | { | |
157f9c00 | 1105 | int i = 0; |
65796348 | 1106 | int tc = t->action >> BLK_TC_SHIFT; |
157f9c00 | 1107 | |
ca1136c9 | 1108 | if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) { |
18cea459 LZ |
1109 | rwbs[i++] = 'N'; |
1110 | goto out; | |
1111 | } | |
1112 | ||
c09c47ca NK |
1113 | if (tc & BLK_TC_FLUSH) |
1114 | rwbs[i++] = 'F'; | |
1115 | ||
65796348 | 1116 | if (tc & BLK_TC_DISCARD) |
157f9c00 | 1117 | rwbs[i++] = 'D'; |
65796348 | 1118 | else if (tc & BLK_TC_WRITE) |
157f9c00 ACM |
1119 | rwbs[i++] = 'W'; |
1120 | else if (t->bytes) | |
1121 | rwbs[i++] = 'R'; | |
1122 | else | |
1123 | rwbs[i++] = 'N'; | |
1124 | ||
c09c47ca NK |
1125 | if (tc & BLK_TC_FUA) |
1126 | rwbs[i++] = 'F'; | |
65796348 | 1127 | if (tc & BLK_TC_AHEAD) |
157f9c00 | 1128 | rwbs[i++] = 'A'; |
65796348 | 1129 | if (tc & BLK_TC_SYNC) |
157f9c00 | 1130 | rwbs[i++] = 'S'; |
65796348 | 1131 | if (tc & BLK_TC_META) |
157f9c00 | 1132 | rwbs[i++] = 'M'; |
18cea459 | 1133 | out: |
157f9c00 | 1134 | rwbs[i] = '\0'; |
c71a8961 ACM |
1135 | } |
1136 | ||
1137 | static inline | |
1138 | const struct blk_io_trace *te_blk_io_trace(const struct trace_entry *ent) | |
1139 | { | |
1140 | return (const struct blk_io_trace *)ent; | |
1141 | } | |
1142 | ||
ca1136c9 SL |
1143 | static inline const void *pdu_start(const struct trace_entry *ent, bool has_cg) |
1144 | { | |
1145 | return (void *)(te_blk_io_trace(ent) + 1) + | |
1146 | (has_cg ? sizeof(union kernfs_node_id) : 0); | |
1147 | } | |
1148 | ||
1149 | static inline const void *cgid_start(const struct trace_entry *ent) | |
c71a8961 | 1150 | { |
ca1136c9 SL |
1151 | return (void *)(te_blk_io_trace(ent) + 1); |
1152 | } | |
1153 | ||
1154 | static inline int pdu_real_len(const struct trace_entry *ent, bool has_cg) | |
1155 | { | |
1156 | return te_blk_io_trace(ent)->pdu_len - | |
1157 | (has_cg ? sizeof(union kernfs_node_id) : 0); | |
c71a8961 ACM |
1158 | } |
1159 | ||
66de7792 LZ |
1160 | static inline u32 t_action(const struct trace_entry *ent) |
1161 | { | |
1162 | return te_blk_io_trace(ent)->action; | |
1163 | } | |
1164 | ||
1165 | static inline u32 t_bytes(const struct trace_entry *ent) | |
1166 | { | |
1167 | return te_blk_io_trace(ent)->bytes; | |
1168 | } | |
1169 | ||
c71a8961 ACM |
1170 | static inline u32 t_sec(const struct trace_entry *ent) |
1171 | { | |
1172 | return te_blk_io_trace(ent)->bytes >> 9; | |
1173 | } | |
1174 | ||
1175 | static inline unsigned long long t_sector(const struct trace_entry *ent) | |
1176 | { | |
1177 | return te_blk_io_trace(ent)->sector; | |
1178 | } | |
1179 | ||
1180 | static inline __u16 t_error(const struct trace_entry *ent) | |
1181 | { | |
e0dc81be | 1182 | return te_blk_io_trace(ent)->error; |
c71a8961 ACM |
1183 | } |
1184 | ||
ca1136c9 | 1185 | static __u64 get_pdu_int(const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1186 | { |
ca1136c9 | 1187 | const __u64 *val = pdu_start(ent, has_cg); |
c71a8961 ACM |
1188 | return be64_to_cpu(*val); |
1189 | } | |
1190 | ||
1191 | static void get_pdu_remap(const struct trace_entry *ent, | |
ca1136c9 | 1192 | struct blk_io_trace_remap *r, bool has_cg) |
c71a8961 | 1193 | { |
ca1136c9 | 1194 | const struct blk_io_trace_remap *__r = pdu_start(ent, has_cg); |
a42aaa3b | 1195 | __u64 sector_from = __r->sector_from; |
c71a8961 | 1196 | |
c71a8961 | 1197 | r->device_from = be32_to_cpu(__r->device_from); |
a42aaa3b AB |
1198 | r->device_to = be32_to_cpu(__r->device_to); |
1199 | r->sector_from = be64_to_cpu(sector_from); | |
c71a8961 ACM |
1200 | } |
1201 | ||
ca1136c9 SL |
1202 | typedef void (blk_log_action_t) (struct trace_iterator *iter, const char *act, |
1203 | bool has_cg); | |
b6a4b0c3 | 1204 | |
ca1136c9 SL |
1205 | static void blk_log_action_classic(struct trace_iterator *iter, const char *act, |
1206 | bool has_cg) | |
c71a8961 | 1207 | { |
c09c47ca | 1208 | char rwbs[RWBS_LEN]; |
35ac51bf LZ |
1209 | unsigned long long ts = iter->ts; |
1210 | unsigned long nsec_rem = do_div(ts, NSEC_PER_SEC); | |
c71a8961 | 1211 | unsigned secs = (unsigned long)ts; |
b6a4b0c3 | 1212 | const struct blk_io_trace *t = te_blk_io_trace(iter->ent); |
c71a8961 ACM |
1213 | |
1214 | fill_rwbs(rwbs, t); | |
1215 | ||
f4a1d08c SRRH |
1216 | trace_seq_printf(&iter->seq, |
1217 | "%3d,%-3d %2d %5d.%09lu %5u %2s %3s ", | |
1218 | MAJOR(t->device), MINOR(t->device), iter->cpu, | |
1219 | secs, nsec_rem, iter->ent->pid, act, rwbs); | |
c71a8961 ACM |
1220 | } |
1221 | ||
ca1136c9 SL |
1222 | static void blk_log_action(struct trace_iterator *iter, const char *act, |
1223 | bool has_cg) | |
c71a8961 | 1224 | { |
c09c47ca | 1225 | char rwbs[RWBS_LEN]; |
b6a4b0c3 LZ |
1226 | const struct blk_io_trace *t = te_blk_io_trace(iter->ent); |
1227 | ||
c71a8961 | 1228 | fill_rwbs(rwbs, t); |
ca1136c9 SL |
1229 | if (has_cg) { |
1230 | const union kernfs_node_id *id = cgid_start(iter->ent); | |
1231 | ||
69fd5c39 SL |
1232 | if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) { |
1233 | char blkcg_name_buf[NAME_MAX + 1] = "<...>"; | |
1234 | ||
1235 | cgroup_path_from_kernfs_id(id, blkcg_name_buf, | |
1236 | sizeof(blkcg_name_buf)); | |
1237 | trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ", | |
1238 | MAJOR(t->device), MINOR(t->device), | |
1239 | blkcg_name_buf, act, rwbs); | |
1240 | } else | |
1241 | trace_seq_printf(&iter->seq, | |
1242 | "%3d,%-3d %x,%-x %2s %3s ", | |
ca1136c9 SL |
1243 | MAJOR(t->device), MINOR(t->device), |
1244 | id->ino, id->generation, act, rwbs); | |
1245 | } else | |
1246 | trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ", | |
1247 | MAJOR(t->device), MINOR(t->device), act, rwbs); | |
c71a8961 ACM |
1248 | } |
1249 | ||
ca1136c9 SL |
1250 | static void blk_log_dump_pdu(struct trace_seq *s, |
1251 | const struct trace_entry *ent, bool has_cg) | |
66de7792 | 1252 | { |
04986257 | 1253 | const unsigned char *pdu_buf; |
66de7792 | 1254 | int pdu_len; |
f4a1d08c | 1255 | int i, end; |
66de7792 | 1256 | |
ca1136c9 SL |
1257 | pdu_buf = pdu_start(ent, has_cg); |
1258 | pdu_len = pdu_real_len(ent, has_cg); | |
66de7792 LZ |
1259 | |
1260 | if (!pdu_len) | |
f4a1d08c | 1261 | return; |
66de7792 LZ |
1262 | |
1263 | /* find the last zero that needs to be printed */ | |
1264 | for (end = pdu_len - 1; end >= 0; end--) | |
1265 | if (pdu_buf[end]) | |
1266 | break; | |
1267 | end++; | |
1268 | ||
f4a1d08c | 1269 | trace_seq_putc(s, '('); |
66de7792 LZ |
1270 | |
1271 | for (i = 0; i < pdu_len; i++) { | |
1272 | ||
f4a1d08c SRRH |
1273 | trace_seq_printf(s, "%s%02x", |
1274 | i == 0 ? "" : " ", pdu_buf[i]); | |
66de7792 LZ |
1275 | |
1276 | /* | |
1277 | * stop when the rest is just zeroes and indicate so | |
1278 | * with a ".." appended | |
1279 | */ | |
f4a1d08c SRRH |
1280 | if (i == end && end != pdu_len - 1) { |
1281 | trace_seq_puts(s, " ..) "); | |
1282 | return; | |
1283 | } | |
66de7792 LZ |
1284 | } |
1285 | ||
f4a1d08c | 1286 | trace_seq_puts(s, ") "); |
66de7792 LZ |
1287 | } |
1288 | ||
ca1136c9 | 1289 | static void blk_log_generic(struct trace_seq *s, const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1290 | { |
4ca53085 SR |
1291 | char cmd[TASK_COMM_LEN]; |
1292 | ||
1293 | trace_find_cmdline(ent->pid, cmd); | |
c71a8961 | 1294 | |
66de7792 | 1295 | if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) { |
f4a1d08c | 1296 | trace_seq_printf(s, "%u ", t_bytes(ent)); |
ca1136c9 | 1297 | blk_log_dump_pdu(s, ent, has_cg); |
f4a1d08c | 1298 | trace_seq_printf(s, "[%s]\n", cmd); |
66de7792 LZ |
1299 | } else { |
1300 | if (t_sec(ent)) | |
f4a1d08c | 1301 | trace_seq_printf(s, "%llu + %u [%s]\n", |
66de7792 | 1302 | t_sector(ent), t_sec(ent), cmd); |
f4a1d08c SRRH |
1303 | else |
1304 | trace_seq_printf(s, "[%s]\n", cmd); | |
66de7792 | 1305 | } |
c71a8961 ACM |
1306 | } |
1307 | ||
f4a1d08c | 1308 | static void blk_log_with_error(struct trace_seq *s, |
ca1136c9 | 1309 | const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1310 | { |
66de7792 | 1311 | if (t_action(ent) & BLK_TC_ACT(BLK_TC_PC)) { |
ca1136c9 | 1312 | blk_log_dump_pdu(s, ent, has_cg); |
f4a1d08c | 1313 | trace_seq_printf(s, "[%d]\n", t_error(ent)); |
66de7792 LZ |
1314 | } else { |
1315 | if (t_sec(ent)) | |
f4a1d08c SRRH |
1316 | trace_seq_printf(s, "%llu + %u [%d]\n", |
1317 | t_sector(ent), | |
1318 | t_sec(ent), t_error(ent)); | |
1319 | else | |
1320 | trace_seq_printf(s, "%llu [%d]\n", | |
1321 | t_sector(ent), t_error(ent)); | |
66de7792 | 1322 | } |
c71a8961 ACM |
1323 | } |
1324 | ||
ca1136c9 | 1325 | static void blk_log_remap(struct trace_seq *s, const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1326 | { |
a42aaa3b | 1327 | struct blk_io_trace_remap r = { .device_from = 0, }; |
c71a8961 | 1328 | |
ca1136c9 | 1329 | get_pdu_remap(ent, &r, has_cg); |
f4a1d08c SRRH |
1330 | trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n", |
1331 | t_sector(ent), t_sec(ent), | |
1332 | MAJOR(r.device_from), MINOR(r.device_from), | |
1333 | (unsigned long long)r.sector_from); | |
c71a8961 ACM |
1334 | } |
1335 | ||
ca1136c9 | 1336 | static void blk_log_plug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1337 | { |
4ca53085 SR |
1338 | char cmd[TASK_COMM_LEN]; |
1339 | ||
1340 | trace_find_cmdline(ent->pid, cmd); | |
1341 | ||
f4a1d08c | 1342 | trace_seq_printf(s, "[%s]\n", cmd); |
c71a8961 ACM |
1343 | } |
1344 | ||
ca1136c9 | 1345 | static void blk_log_unplug(struct trace_seq *s, const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1346 | { |
4ca53085 SR |
1347 | char cmd[TASK_COMM_LEN]; |
1348 | ||
1349 | trace_find_cmdline(ent->pid, cmd); | |
1350 | ||
ca1136c9 | 1351 | trace_seq_printf(s, "[%s] %llu\n", cmd, get_pdu_int(ent, has_cg)); |
c71a8961 ACM |
1352 | } |
1353 | ||
ca1136c9 | 1354 | static void blk_log_split(struct trace_seq *s, const struct trace_entry *ent, bool has_cg) |
c71a8961 | 1355 | { |
4ca53085 SR |
1356 | char cmd[TASK_COMM_LEN]; |
1357 | ||
1358 | trace_find_cmdline(ent->pid, cmd); | |
1359 | ||
f4a1d08c | 1360 | trace_seq_printf(s, "%llu / %llu [%s]\n", t_sector(ent), |
ca1136c9 | 1361 | get_pdu_int(ent, has_cg), cmd); |
c71a8961 ACM |
1362 | } |
1363 | ||
ca1136c9 SL |
1364 | static void blk_log_msg(struct trace_seq *s, const struct trace_entry *ent, |
1365 | bool has_cg) | |
18cea459 | 1366 | { |
18cea459 | 1367 | |
ca1136c9 SL |
1368 | trace_seq_putmem(s, pdu_start(ent, has_cg), |
1369 | pdu_real_len(ent, has_cg)); | |
f4a1d08c | 1370 | trace_seq_putc(s, '\n'); |
18cea459 LZ |
1371 | } |
1372 | ||
c71a8961 ACM |
1373 | /* |
1374 | * struct tracer operations | |
1375 | */ | |
1376 | ||
1377 | static void blk_tracer_print_header(struct seq_file *m) | |
1378 | { | |
1379 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) | |
1380 | return; | |
1381 | seq_puts(m, "# DEV CPU TIMESTAMP PID ACT FLG\n" | |
1382 | "# | | | | | |\n"); | |
1383 | } | |
1384 | ||
1385 | static void blk_tracer_start(struct trace_array *tr) | |
1386 | { | |
ad5dd549 | 1387 | blk_tracer_enabled = true; |
c71a8961 ACM |
1388 | } |
1389 | ||
1390 | static int blk_tracer_init(struct trace_array *tr) | |
1391 | { | |
1392 | blk_tr = tr; | |
1393 | blk_tracer_start(tr); | |
c71a8961 ACM |
1394 | return 0; |
1395 | } | |
1396 | ||
1397 | static void blk_tracer_stop(struct trace_array *tr) | |
1398 | { | |
ad5dd549 | 1399 | blk_tracer_enabled = false; |
c71a8961 ACM |
1400 | } |
1401 | ||
1402 | static void blk_tracer_reset(struct trace_array *tr) | |
1403 | { | |
c71a8961 ACM |
1404 | blk_tracer_stop(tr); |
1405 | } | |
1406 | ||
e4955c99 | 1407 | static const struct { |
c71a8961 | 1408 | const char *act[2]; |
ca1136c9 SL |
1409 | void (*print)(struct trace_seq *s, const struct trace_entry *ent, |
1410 | bool has_cg); | |
e4955c99 | 1411 | } what2act[] = { |
ef18012b | 1412 | [__BLK_TA_QUEUE] = {{ "Q", "queue" }, blk_log_generic }, |
c71a8961 ACM |
1413 | [__BLK_TA_BACKMERGE] = {{ "M", "backmerge" }, blk_log_generic }, |
1414 | [__BLK_TA_FRONTMERGE] = {{ "F", "frontmerge" }, blk_log_generic }, | |
1415 | [__BLK_TA_GETRQ] = {{ "G", "getrq" }, blk_log_generic }, | |
1416 | [__BLK_TA_SLEEPRQ] = {{ "S", "sleeprq" }, blk_log_generic }, | |
1417 | [__BLK_TA_REQUEUE] = {{ "R", "requeue" }, blk_log_with_error }, | |
1418 | [__BLK_TA_ISSUE] = {{ "D", "issue" }, blk_log_generic }, | |
1419 | [__BLK_TA_COMPLETE] = {{ "C", "complete" }, blk_log_with_error }, | |
1420 | [__BLK_TA_PLUG] = {{ "P", "plug" }, blk_log_plug }, | |
1421 | [__BLK_TA_UNPLUG_IO] = {{ "U", "unplug_io" }, blk_log_unplug }, | |
49cac01e | 1422 | [__BLK_TA_UNPLUG_TIMER] = {{ "UT", "unplug_timer" }, blk_log_unplug }, |
c71a8961 ACM |
1423 | [__BLK_TA_INSERT] = {{ "I", "insert" }, blk_log_generic }, |
1424 | [__BLK_TA_SPLIT] = {{ "X", "split" }, blk_log_split }, | |
1425 | [__BLK_TA_BOUNCE] = {{ "B", "bounce" }, blk_log_generic }, | |
1426 | [__BLK_TA_REMAP] = {{ "A", "remap" }, blk_log_remap }, | |
1427 | }; | |
1428 | ||
b6a4b0c3 LZ |
1429 | static enum print_line_t print_one_line(struct trace_iterator *iter, |
1430 | bool classic) | |
c71a8961 | 1431 | { |
983f938a | 1432 | struct trace_array *tr = iter->tr; |
2c9b238e | 1433 | struct trace_seq *s = &iter->seq; |
b6a4b0c3 LZ |
1434 | const struct blk_io_trace *t; |
1435 | u16 what; | |
b6a4b0c3 LZ |
1436 | bool long_act; |
1437 | blk_log_action_t *log_action; | |
ca1136c9 | 1438 | bool has_cg; |
c71a8961 | 1439 | |
b6a4b0c3 | 1440 | t = te_blk_io_trace(iter->ent); |
ca1136c9 | 1441 | what = (t->action & ((1 << BLK_TC_SHIFT) - 1)) & ~__BLK_TA_CGROUP; |
983f938a | 1442 | long_act = !!(tr->trace_flags & TRACE_ITER_VERBOSE); |
b6a4b0c3 | 1443 | log_action = classic ? &blk_log_action_classic : &blk_log_action; |
ca1136c9 | 1444 | has_cg = t->action & __BLK_TA_CGROUP; |
08a06b83 | 1445 | |
ca1136c9 SL |
1446 | if ((t->action & ~__BLK_TN_CGROUP) == BLK_TN_MESSAGE) { |
1447 | log_action(iter, long_act ? "message" : "m", has_cg); | |
1448 | blk_log_msg(s, iter->ent, has_cg); | |
b7d7641e | 1449 | return trace_handle_return(s); |
18cea459 LZ |
1450 | } |
1451 | ||
eb08f8eb | 1452 | if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act))) |
f4a1d08c | 1453 | trace_seq_printf(s, "Unknown action %x\n", what); |
c71a8961 | 1454 | else { |
ca1136c9 SL |
1455 | log_action(iter, what2act[what].act[long_act], has_cg); |
1456 | what2act[what].print(s, iter->ent, has_cg); | |
c71a8961 | 1457 | } |
f4a1d08c SRRH |
1458 | |
1459 | return trace_handle_return(s); | |
c71a8961 ACM |
1460 | } |
1461 | ||
b6a4b0c3 | 1462 | static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, |
a9a57763 | 1463 | int flags, struct trace_event *event) |
b6a4b0c3 | 1464 | { |
b6a4b0c3 LZ |
1465 | return print_one_line(iter, false); |
1466 | } | |
1467 | ||
f4a1d08c | 1468 | static void blk_trace_synthesize_old_trace(struct trace_iterator *iter) |
08a06b83 ACM |
1469 | { |
1470 | struct trace_seq *s = &iter->seq; | |
1471 | struct blk_io_trace *t = (struct blk_io_trace *)iter->ent; | |
1472 | const int offset = offsetof(struct blk_io_trace, sector); | |
1473 | struct blk_io_trace old = { | |
1474 | .magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION, | |
6c051ce0 | 1475 | .time = iter->ts, |
08a06b83 ACM |
1476 | }; |
1477 | ||
f4a1d08c SRRH |
1478 | trace_seq_putmem(s, &old, offset); |
1479 | trace_seq_putmem(s, &t->sector, | |
1480 | sizeof(old) - offset + t->pdu_len); | |
08a06b83 ACM |
1481 | } |
1482 | ||
ae7462b4 | 1483 | static enum print_line_t |
a9a57763 SR |
1484 | blk_trace_event_print_binary(struct trace_iterator *iter, int flags, |
1485 | struct trace_event *event) | |
08a06b83 | 1486 | { |
f4a1d08c SRRH |
1487 | blk_trace_synthesize_old_trace(iter); |
1488 | ||
1489 | return trace_handle_return(&iter->seq); | |
08a06b83 ACM |
1490 | } |
1491 | ||
c71a8961 ACM |
1492 | static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) |
1493 | { | |
c71a8961 ACM |
1494 | if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC)) |
1495 | return TRACE_TYPE_UNHANDLED; | |
1496 | ||
b6a4b0c3 | 1497 | return print_one_line(iter, true); |
c71a8961 ACM |
1498 | } |
1499 | ||
8c1a49ae SRRH |
1500 | static int |
1501 | blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
f3948f88 LZ |
1502 | { |
1503 | /* don't output context-info for blk_classic output */ | |
1504 | if (bit == TRACE_BLK_OPT_CLASSIC) { | |
1505 | if (set) | |
983f938a | 1506 | tr->trace_flags &= ~TRACE_ITER_CONTEXT_INFO; |
f3948f88 | 1507 | else |
983f938a | 1508 | tr->trace_flags |= TRACE_ITER_CONTEXT_INFO; |
f3948f88 LZ |
1509 | } |
1510 | return 0; | |
1511 | } | |
1512 | ||
c71a8961 ACM |
1513 | static struct tracer blk_tracer __read_mostly = { |
1514 | .name = "blk", | |
1515 | .init = blk_tracer_init, | |
1516 | .reset = blk_tracer_reset, | |
1517 | .start = blk_tracer_start, | |
1518 | .stop = blk_tracer_stop, | |
1519 | .print_header = blk_tracer_print_header, | |
1520 | .print_line = blk_tracer_print_line, | |
1521 | .flags = &blk_tracer_flags, | |
f3948f88 | 1522 | .set_flag = blk_tracer_set_flag, |
c71a8961 ACM |
1523 | }; |
1524 | ||
a9a57763 | 1525 | static struct trace_event_functions trace_blk_event_funcs = { |
c71a8961 | 1526 | .trace = blk_trace_event_print, |
08a06b83 | 1527 | .binary = blk_trace_event_print_binary, |
c71a8961 ACM |
1528 | }; |
1529 | ||
a9a57763 SR |
1530 | static struct trace_event trace_blk_event = { |
1531 | .type = TRACE_BLK, | |
1532 | .funcs = &trace_blk_event_funcs, | |
1533 | }; | |
1534 | ||
c71a8961 ACM |
1535 | static int __init init_blk_tracer(void) |
1536 | { | |
9023c930 | 1537 | if (!register_trace_event(&trace_blk_event)) { |
a395d6a7 | 1538 | pr_warn("Warning: could not register block events\n"); |
c71a8961 ACM |
1539 | return 1; |
1540 | } | |
1541 | ||
1542 | if (register_tracer(&blk_tracer) != 0) { | |
a395d6a7 | 1543 | pr_warn("Warning: could not register the block tracer\n"); |
9023c930 | 1544 | unregister_trace_event(&trace_blk_event); |
c71a8961 ACM |
1545 | return 1; |
1546 | } | |
1547 | ||
1548 | return 0; | |
1549 | } | |
1550 | ||
1551 | device_initcall(init_blk_tracer); | |
1552 | ||
1553 | static int blk_trace_remove_queue(struct request_queue *q) | |
1554 | { | |
1555 | struct blk_trace *bt; | |
1556 | ||
1557 | bt = xchg(&q->blk_trace, NULL); | |
1558 | if (bt == NULL) | |
1559 | return -EINVAL; | |
1560 | ||
17ba97e3 LZ |
1561 | if (atomic_dec_and_test(&blk_probes_ref)) |
1562 | blk_unregister_tracepoints(); | |
1563 | ||
ad5dd549 | 1564 | blk_trace_free(bt); |
c71a8961 ACM |
1565 | return 0; |
1566 | } | |
1567 | ||
1568 | /* | |
1569 | * Setup everything required to start tracing | |
1570 | */ | |
9908c309 LZ |
1571 | static int blk_trace_setup_queue(struct request_queue *q, |
1572 | struct block_device *bdev) | |
c71a8961 | 1573 | { |
cdea01b2 | 1574 | struct blk_trace *bt = NULL; |
18cea459 | 1575 | int ret = -ENOMEM; |
c71a8961 | 1576 | |
c71a8961 ACM |
1577 | bt = kzalloc(sizeof(*bt), GFP_KERNEL); |
1578 | if (!bt) | |
15152e44 | 1579 | return -ENOMEM; |
c71a8961 | 1580 | |
18cea459 LZ |
1581 | bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); |
1582 | if (!bt->msg_data) | |
1583 | goto free_bt; | |
1584 | ||
9908c309 | 1585 | bt->dev = bdev->bd_dev; |
c71a8961 | 1586 | bt->act_mask = (u16)-1; |
9908c309 LZ |
1587 | |
1588 | blk_trace_setup_lba(bt, bdev); | |
c71a8961 | 1589 | |
cdea01b2 DB |
1590 | ret = -EBUSY; |
1591 | if (cmpxchg(&q->blk_trace, NULL, bt)) | |
18cea459 | 1592 | goto free_bt; |
15152e44 | 1593 | |
17ba97e3 LZ |
1594 | if (atomic_inc_return(&blk_probes_ref) == 1) |
1595 | blk_register_tracepoints(); | |
c71a8961 | 1596 | return 0; |
18cea459 LZ |
1597 | |
1598 | free_bt: | |
1599 | blk_trace_free(bt); | |
1600 | return ret; | |
c71a8961 ACM |
1601 | } |
1602 | ||
1603 | /* | |
1604 | * sysfs interface to enable and configure tracing | |
1605 | */ | |
1606 | ||
c71a8961 ACM |
1607 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
1608 | struct device_attribute *attr, | |
1609 | char *buf); | |
1610 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1611 | struct device_attribute *attr, | |
1612 | const char *buf, size_t count); | |
1613 | #define BLK_TRACE_DEVICE_ATTR(_name) \ | |
1614 | DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \ | |
1615 | sysfs_blk_trace_attr_show, \ | |
1616 | sysfs_blk_trace_attr_store) | |
1617 | ||
cd649b8b | 1618 | static BLK_TRACE_DEVICE_ATTR(enable); |
c71a8961 ACM |
1619 | static BLK_TRACE_DEVICE_ATTR(act_mask); |
1620 | static BLK_TRACE_DEVICE_ATTR(pid); | |
1621 | static BLK_TRACE_DEVICE_ATTR(start_lba); | |
1622 | static BLK_TRACE_DEVICE_ATTR(end_lba); | |
1623 | ||
1624 | static struct attribute *blk_trace_attrs[] = { | |
1625 | &dev_attr_enable.attr, | |
1626 | &dev_attr_act_mask.attr, | |
1627 | &dev_attr_pid.attr, | |
1628 | &dev_attr_start_lba.attr, | |
1629 | &dev_attr_end_lba.attr, | |
1630 | NULL | |
1631 | }; | |
1632 | ||
1633 | struct attribute_group blk_trace_attr_group = { | |
1634 | .name = "trace", | |
1635 | .attrs = blk_trace_attrs, | |
1636 | }; | |
1637 | ||
09341997 LZ |
1638 | static const struct { |
1639 | int mask; | |
1640 | const char *str; | |
1641 | } mask_maps[] = { | |
1642 | { BLK_TC_READ, "read" }, | |
1643 | { BLK_TC_WRITE, "write" }, | |
c09c47ca | 1644 | { BLK_TC_FLUSH, "flush" }, |
09341997 LZ |
1645 | { BLK_TC_SYNC, "sync" }, |
1646 | { BLK_TC_QUEUE, "queue" }, | |
1647 | { BLK_TC_REQUEUE, "requeue" }, | |
1648 | { BLK_TC_ISSUE, "issue" }, | |
1649 | { BLK_TC_COMPLETE, "complete" }, | |
1650 | { BLK_TC_FS, "fs" }, | |
1651 | { BLK_TC_PC, "pc" }, | |
8d1547e0 | 1652 | { BLK_TC_NOTIFY, "notify" }, |
09341997 LZ |
1653 | { BLK_TC_AHEAD, "ahead" }, |
1654 | { BLK_TC_META, "meta" }, | |
1655 | { BLK_TC_DISCARD, "discard" }, | |
1656 | { BLK_TC_DRV_DATA, "drv_data" }, | |
c09c47ca | 1657 | { BLK_TC_FUA, "fua" }, |
09341997 LZ |
1658 | }; |
1659 | ||
1660 | static int blk_trace_str2mask(const char *str) | |
c71a8961 | 1661 | { |
09341997 | 1662 | int i; |
c71a8961 | 1663 | int mask = 0; |
9eb85125 | 1664 | char *buf, *s, *token; |
c71a8961 | 1665 | |
9eb85125 LZ |
1666 | buf = kstrdup(str, GFP_KERNEL); |
1667 | if (buf == NULL) | |
c71a8961 | 1668 | return -ENOMEM; |
9eb85125 | 1669 | s = strstrip(buf); |
c71a8961 ACM |
1670 | |
1671 | while (1) { | |
09341997 LZ |
1672 | token = strsep(&s, ","); |
1673 | if (token == NULL) | |
c71a8961 ACM |
1674 | break; |
1675 | ||
09341997 LZ |
1676 | if (*token == '\0') |
1677 | continue; | |
1678 | ||
1679 | for (i = 0; i < ARRAY_SIZE(mask_maps); i++) { | |
1680 | if (strcasecmp(token, mask_maps[i].str) == 0) { | |
1681 | mask |= mask_maps[i].mask; | |
1682 | break; | |
1683 | } | |
1684 | } | |
1685 | if (i == ARRAY_SIZE(mask_maps)) { | |
1686 | mask = -EINVAL; | |
1687 | break; | |
1688 | } | |
c71a8961 | 1689 | } |
9eb85125 | 1690 | kfree(buf); |
c71a8961 ACM |
1691 | |
1692 | return mask; | |
1693 | } | |
1694 | ||
09341997 LZ |
1695 | static ssize_t blk_trace_mask2str(char *buf, int mask) |
1696 | { | |
1697 | int i; | |
1698 | char *p = buf; | |
1699 | ||
1700 | for (i = 0; i < ARRAY_SIZE(mask_maps); i++) { | |
1701 | if (mask & mask_maps[i].mask) { | |
1702 | p += sprintf(p, "%s%s", | |
1703 | (p == buf) ? "" : ",", mask_maps[i].str); | |
1704 | } | |
1705 | } | |
1706 | *p++ = '\n'; | |
1707 | ||
1708 | return p - buf; | |
1709 | } | |
1710 | ||
b125130b LZ |
1711 | static struct request_queue *blk_trace_get_queue(struct block_device *bdev) |
1712 | { | |
1713 | if (bdev->bd_disk == NULL) | |
1714 | return NULL; | |
1715 | ||
1716 | return bdev_get_queue(bdev); | |
1717 | } | |
1718 | ||
c71a8961 ACM |
1719 | static ssize_t sysfs_blk_trace_attr_show(struct device *dev, |
1720 | struct device_attribute *attr, | |
1721 | char *buf) | |
1722 | { | |
1723 | struct hd_struct *p = dev_to_part(dev); | |
1724 | struct request_queue *q; | |
1725 | struct block_device *bdev; | |
1726 | ssize_t ret = -ENXIO; | |
1727 | ||
c71a8961 ACM |
1728 | bdev = bdget(part_devt(p)); |
1729 | if (bdev == NULL) | |
01b284f9 | 1730 | goto out; |
c71a8961 | 1731 | |
b125130b | 1732 | q = blk_trace_get_queue(bdev); |
c71a8961 ACM |
1733 | if (q == NULL) |
1734 | goto out_bdput; | |
b125130b | 1735 | |
5acb3cc2 | 1736 | mutex_lock(&q->blk_trace_mutex); |
cd649b8b LZ |
1737 | |
1738 | if (attr == &dev_attr_enable) { | |
1739 | ret = sprintf(buf, "%u\n", !!q->blk_trace); | |
1740 | goto out_unlock_bdev; | |
1741 | } | |
1742 | ||
c71a8961 ACM |
1743 | if (q->blk_trace == NULL) |
1744 | ret = sprintf(buf, "disabled\n"); | |
1745 | else if (attr == &dev_attr_act_mask) | |
09341997 | 1746 | ret = blk_trace_mask2str(buf, q->blk_trace->act_mask); |
c71a8961 ACM |
1747 | else if (attr == &dev_attr_pid) |
1748 | ret = sprintf(buf, "%u\n", q->blk_trace->pid); | |
1749 | else if (attr == &dev_attr_start_lba) | |
1750 | ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba); | |
1751 | else if (attr == &dev_attr_end_lba) | |
1752 | ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba); | |
cd649b8b LZ |
1753 | |
1754 | out_unlock_bdev: | |
5acb3cc2 | 1755 | mutex_unlock(&q->blk_trace_mutex); |
c71a8961 ACM |
1756 | out_bdput: |
1757 | bdput(bdev); | |
01b284f9 | 1758 | out: |
c71a8961 ACM |
1759 | return ret; |
1760 | } | |
1761 | ||
1762 | static ssize_t sysfs_blk_trace_attr_store(struct device *dev, | |
1763 | struct device_attribute *attr, | |
1764 | const char *buf, size_t count) | |
1765 | { | |
1766 | struct block_device *bdev; | |
1767 | struct request_queue *q; | |
1768 | struct hd_struct *p; | |
1769 | u64 value; | |
09341997 | 1770 | ssize_t ret = -EINVAL; |
c71a8961 ACM |
1771 | |
1772 | if (count == 0) | |
1773 | goto out; | |
1774 | ||
1775 | if (attr == &dev_attr_act_mask) { | |
5f339453 | 1776 | if (kstrtoull(buf, 0, &value)) { |
c71a8961 | 1777 | /* Assume it is a list of trace category names */ |
09341997 LZ |
1778 | ret = blk_trace_str2mask(buf); |
1779 | if (ret < 0) | |
c71a8961 | 1780 | goto out; |
09341997 | 1781 | value = ret; |
c71a8961 | 1782 | } |
5f339453 | 1783 | } else if (kstrtoull(buf, 0, &value)) |
c71a8961 ACM |
1784 | goto out; |
1785 | ||
09341997 LZ |
1786 | ret = -ENXIO; |
1787 | ||
c71a8961 ACM |
1788 | p = dev_to_part(dev); |
1789 | bdev = bdget(part_devt(p)); | |
1790 | if (bdev == NULL) | |
01b284f9 | 1791 | goto out; |
c71a8961 | 1792 | |
b125130b | 1793 | q = blk_trace_get_queue(bdev); |
c71a8961 ACM |
1794 | if (q == NULL) |
1795 | goto out_bdput; | |
1796 | ||
5acb3cc2 | 1797 | mutex_lock(&q->blk_trace_mutex); |
cd649b8b LZ |
1798 | |
1799 | if (attr == &dev_attr_enable) { | |
1800 | if (value) | |
9908c309 | 1801 | ret = blk_trace_setup_queue(q, bdev); |
cd649b8b LZ |
1802 | else |
1803 | ret = blk_trace_remove_queue(q); | |
1804 | goto out_unlock_bdev; | |
1805 | } | |
1806 | ||
c71a8961 ACM |
1807 | ret = 0; |
1808 | if (q->blk_trace == NULL) | |
9908c309 | 1809 | ret = blk_trace_setup_queue(q, bdev); |
c71a8961 ACM |
1810 | |
1811 | if (ret == 0) { | |
1812 | if (attr == &dev_attr_act_mask) | |
1813 | q->blk_trace->act_mask = value; | |
1814 | else if (attr == &dev_attr_pid) | |
1815 | q->blk_trace->pid = value; | |
1816 | else if (attr == &dev_attr_start_lba) | |
1817 | q->blk_trace->start_lba = value; | |
1818 | else if (attr == &dev_attr_end_lba) | |
1819 | q->blk_trace->end_lba = value; | |
c71a8961 | 1820 | } |
cd649b8b LZ |
1821 | |
1822 | out_unlock_bdev: | |
5acb3cc2 | 1823 | mutex_unlock(&q->blk_trace_mutex); |
c71a8961 ACM |
1824 | out_bdput: |
1825 | bdput(bdev); | |
c71a8961 | 1826 | out: |
cd649b8b | 1827 | return ret ? ret : count; |
c71a8961 | 1828 | } |
cd649b8b | 1829 | |
1d54ad6d LZ |
1830 | int blk_trace_init_sysfs(struct device *dev) |
1831 | { | |
1832 | return sysfs_create_group(&dev->kobj, &blk_trace_attr_group); | |
1833 | } | |
1834 | ||
48c0d4d4 ZK |
1835 | void blk_trace_remove_sysfs(struct device *dev) |
1836 | { | |
1837 | sysfs_remove_group(&dev->kobj, &blk_trace_attr_group); | |
1838 | } | |
1839 | ||
55782138 LZ |
1840 | #endif /* CONFIG_BLK_DEV_IO_TRACE */ |
1841 | ||
1842 | #ifdef CONFIG_EVENT_TRACING | |
1843 | ||
ef295ecf | 1844 | void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes) |
55782138 LZ |
1845 | { |
1846 | int i = 0; | |
1847 | ||
ef295ecf | 1848 | if (op & REQ_PREFLUSH) |
c09c47ca NK |
1849 | rwbs[i++] = 'F'; |
1850 | ||
ef295ecf | 1851 | switch (op & REQ_OP_MASK) { |
1b9a9ab7 MC |
1852 | case REQ_OP_WRITE: |
1853 | case REQ_OP_WRITE_SAME: | |
55782138 | 1854 | rwbs[i++] = 'W'; |
1b9a9ab7 MC |
1855 | break; |
1856 | case REQ_OP_DISCARD: | |
55782138 | 1857 | rwbs[i++] = 'D'; |
1b9a9ab7 | 1858 | break; |
288dab8a CH |
1859 | case REQ_OP_SECURE_ERASE: |
1860 | rwbs[i++] = 'D'; | |
1861 | rwbs[i++] = 'E'; | |
1862 | break; | |
3a5e02ce MC |
1863 | case REQ_OP_FLUSH: |
1864 | rwbs[i++] = 'F'; | |
1865 | break; | |
1b9a9ab7 | 1866 | case REQ_OP_READ: |
55782138 | 1867 | rwbs[i++] = 'R'; |
1b9a9ab7 MC |
1868 | break; |
1869 | default: | |
55782138 | 1870 | rwbs[i++] = 'N'; |
1b9a9ab7 | 1871 | } |
55782138 | 1872 | |
ef295ecf | 1873 | if (op & REQ_FUA) |
c09c47ca | 1874 | rwbs[i++] = 'F'; |
ef295ecf | 1875 | if (op & REQ_RAHEAD) |
55782138 | 1876 | rwbs[i++] = 'A'; |
ef295ecf | 1877 | if (op & REQ_SYNC) |
55782138 | 1878 | rwbs[i++] = 'S'; |
ef295ecf | 1879 | if (op & REQ_META) |
55782138 LZ |
1880 | rwbs[i++] = 'M'; |
1881 | ||
1882 | rwbs[i] = '\0'; | |
1883 | } | |
9ca8f8e5 | 1884 | EXPORT_SYMBOL_GPL(blk_fill_rwbs); |
55782138 | 1885 | |
55782138 LZ |
1886 | #endif /* CONFIG_EVENT_TRACING */ |
1887 |