xref: /linux/drivers/md/dm-vdo/dump.c (revision 0340dc4c82590d8735c58cf904a8aa1173273ab5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2023 Red Hat
4  */
5 
6 #include "dump.h"
7 
8 #include <linux/module.h>
9 
10 #include "memory-alloc.h"
11 #include "string-utils.h"
12 
13 #include "constants.h"
14 #include "data-vio.h"
15 #include "dedupe.h"
16 #include "funnel-workqueue.h"
17 #include "io-submitter.h"
18 #include "logger.h"
19 #include "types.h"
20 #include "vdo.h"
21 
22 enum dump_options {
23 	/* Work queues */
24 	SHOW_QUEUES,
25 	/* Memory pools */
26 	SHOW_VIO_POOL,
27 	/* Others */
28 	SHOW_VDO_STATUS,
29 	/* This one means an option overrides the "default" choices, instead of altering them. */
30 	SKIP_DEFAULT
31 };
32 
33 enum dump_option_flags {
34 	/* Work queues */
35 	FLAG_SHOW_QUEUES = (1 << SHOW_QUEUES),
36 	/* Memory pools */
37 	FLAG_SHOW_VIO_POOL = (1 << SHOW_VIO_POOL),
38 	/* Others */
39 	FLAG_SHOW_VDO_STATUS = (1 << SHOW_VDO_STATUS),
40 	/* Special */
41 	FLAG_SKIP_DEFAULT = (1 << SKIP_DEFAULT)
42 };
43 
44 #define FLAGS_ALL_POOLS (FLAG_SHOW_VIO_POOL)
45 #define DEFAULT_DUMP_FLAGS (FLAG_SHOW_QUEUES | FLAG_SHOW_VDO_STATUS)
46 /* Another static buffer... log10(256) = 2.408+, round up: */
47 #define DIGITS_PER_U64 (1 + sizeof(u64) * 2409 / 1000)
48 
49 static inline bool is_arg_string(const char *arg, const char *this_option)
50 {
51 	/* convention seems to be case-independent options */
52 	return strncasecmp(arg, this_option, strlen(this_option)) == 0;
53 }
54 
55 static void do_dump(struct vdo *vdo, unsigned int dump_options_requested,
56 		    const char *why)
57 {
58 	u32 active, maximum;
59 	s64 outstanding;
60 
61 	vdo_log_info("%s dump triggered via %s", VDO_LOGGING_MODULE_NAME, why);
62 	active = get_data_vio_pool_active_requests(vdo->data_vio_pool);
63 	maximum = get_data_vio_pool_maximum_requests(vdo->data_vio_pool);
64 	outstanding = (atomic64_read(&vdo->stats.bios_submitted) -
65 		       atomic64_read(&vdo->stats.bios_completed));
66 	vdo_log_info("%u device requests outstanding (max %u), %lld bio requests outstanding, device '%s'",
67 		     active, maximum, outstanding,
68 		     vdo_get_device_name(vdo->device_config->owning_target));
69 	if (((dump_options_requested & FLAG_SHOW_QUEUES) != 0) && (vdo->threads != NULL)) {
70 		thread_id_t id;
71 
72 		for (id = 0; id < vdo->thread_config.thread_count; id++)
73 			vdo_dump_work_queue(vdo->threads[id].queue);
74 	}
75 
76 	vdo_dump_hash_zones(vdo->hash_zones);
77 	dump_data_vio_pool(vdo->data_vio_pool,
78 			   (dump_options_requested & FLAG_SHOW_VIO_POOL) != 0);
79 	if ((dump_options_requested & FLAG_SHOW_VDO_STATUS) != 0)
80 		vdo_dump_status(vdo);
81 
82 	vdo_report_memory_usage();
83 	vdo_log_info("end of %s dump", VDO_LOGGING_MODULE_NAME);
84 }
85 
86 static int parse_dump_options(unsigned int argc, char *const *argv,
87 			      unsigned int *dump_options_requested_ptr)
88 {
89 	unsigned int dump_options_requested = 0;
90 
91 	static const struct {
92 		const char *name;
93 		unsigned int flags;
94 	} option_names[] = {
95 		{ "viopool", FLAG_SKIP_DEFAULT | FLAG_SHOW_VIO_POOL },
96 		{ "vdo", FLAG_SKIP_DEFAULT | FLAG_SHOW_VDO_STATUS },
97 		{ "pools", FLAG_SKIP_DEFAULT | FLAGS_ALL_POOLS },
98 		{ "queues", FLAG_SKIP_DEFAULT | FLAG_SHOW_QUEUES },
99 		{ "threads", FLAG_SKIP_DEFAULT | FLAG_SHOW_QUEUES },
100 		{ "default", FLAG_SKIP_DEFAULT | DEFAULT_DUMP_FLAGS },
101 		{ "all", ~0 },
102 	};
103 
104 	bool options_okay = true;
105 	unsigned int i;
106 
107 	for (i = 1; i < argc; i++) {
108 		unsigned int j;
109 
110 		for (j = 0; j < ARRAY_SIZE(option_names); j++) {
111 			if (is_arg_string(argv[i], option_names[j].name)) {
112 				dump_options_requested |= option_names[j].flags;
113 				break;
114 			}
115 		}
116 		if (j == ARRAY_SIZE(option_names)) {
117 			vdo_log_warning("dump option name '%s' unknown", argv[i]);
118 			options_okay = false;
119 		}
120 	}
121 	if (!options_okay)
122 		return -EINVAL;
123 	if ((dump_options_requested & FLAG_SKIP_DEFAULT) == 0)
124 		dump_options_requested |= DEFAULT_DUMP_FLAGS;
125 	*dump_options_requested_ptr = dump_options_requested;
126 	return 0;
127 }
128 
129 /* Dump as specified by zero or more string arguments. */
130 int vdo_dump(struct vdo *vdo, unsigned int argc, char *const *argv, const char *why)
131 {
132 	unsigned int dump_options_requested = 0;
133 	int result = parse_dump_options(argc, argv, &dump_options_requested);
134 
135 	if (result != 0)
136 		return result;
137 
138 	do_dump(vdo, dump_options_requested, why);
139 	return 0;
140 }
141 
142 /* Dump everything we know how to dump */
143 void vdo_dump_all(struct vdo *vdo, const char *why)
144 {
145 	do_dump(vdo, ~0, why);
146 }
147 
148 /*
149  * Dump out the data_vio waiters on a waitq.
150  * wait_on should be the label to print for queue (e.g. logical or physical)
151  */
152 static void dump_vio_waiters(struct vdo_wait_queue *waitq, char *wait_on)
153 {
154 	struct vdo_waiter *waiter, *first = vdo_waitq_get_first_waiter(waitq);
155 	struct data_vio *data_vio;
156 
157 	if (first == NULL)
158 		return;
159 
160 	data_vio = vdo_waiter_as_data_vio(first);
161 
162 	vdo_log_info("      %s is locked. Waited on by: vio %px pbn %llu lbn %llu d-pbn %llu lastOp %s",
163 		     wait_on, data_vio, data_vio->allocation.pbn, data_vio->logical.lbn,
164 		     data_vio->duplicate.pbn, get_data_vio_operation_name(data_vio));
165 
166 	for (waiter = first->next_waiter; waiter != first; waiter = waiter->next_waiter) {
167 		data_vio = vdo_waiter_as_data_vio(waiter);
168 		vdo_log_info("     ... and : vio %px pbn %llu lbn %llu d-pbn %llu lastOp %s",
169 			     data_vio, data_vio->allocation.pbn, data_vio->logical.lbn,
170 			     data_vio->duplicate.pbn,
171 			     get_data_vio_operation_name(data_vio));
172 	}
173 }
174 
175 /*
176  * Encode various attributes of a data_vio as a string of one-character flags. This encoding is for
177  * logging brevity:
178  *
179  * R => vio completion result not VDO_SUCCESS
180  * W => vio is on a waitq
181  * D => vio is a duplicate
182  * p => vio is a partial block operation
183  * z => vio is a zero block
184  * d => vio is a discard
185  *
186  * The common case of no flags set will result in an empty, null-terminated buffer. If any flags
187  * are encoded, the first character in the string will be a space character.
188  */
189 static void encode_vio_dump_flags(struct data_vio *data_vio, char buffer[8])
190 {
191 	char *p_flag = buffer;
192 	*p_flag++ = ' ';
193 	if (data_vio->vio.completion.result != VDO_SUCCESS)
194 		*p_flag++ = 'R';
195 	if (data_vio->waiter.next_waiter != NULL)
196 		*p_flag++ = 'W';
197 	if (data_vio->is_duplicate)
198 		*p_flag++ = 'D';
199 	if (data_vio->is_partial)
200 		*p_flag++ = 'p';
201 	if (data_vio->is_zero)
202 		*p_flag++ = 'z';
203 	if (data_vio->remaining_discard > 0)
204 		*p_flag++ = 'd';
205 	if (p_flag == &buffer[1]) {
206 		/* No flags, so remove the blank space. */
207 		p_flag = buffer;
208 	}
209 	*p_flag = '\0';
210 }
211 
212 /* Implements buffer_dump_function. */
213 void dump_data_vio(void *data)
214 {
215 	struct data_vio *data_vio = data;
216 
217 	/*
218 	 * This just needs to be big enough to hold a queue (thread) name and a function name (plus
219 	 * a separator character and NUL). The latter is limited only by taste.
220 	 *
221 	 * In making this static, we're assuming only one "dump" will run at a time. If more than
222 	 * one does run, the log output will be garbled anyway.
223 	 */
224 	static char vio_completion_dump_buffer[100 + MAX_VDO_WORK_QUEUE_NAME_LEN];
225 	static char vio_block_number_dump_buffer[sizeof("P L D") + 3 * DIGITS_PER_U64];
226 	static char vio_flush_generation_buffer[sizeof(" FG") + DIGITS_PER_U64];
227 	static char flags_dump_buffer[8];
228 
229 	/*
230 	 * We're likely to be logging a couple thousand of these lines, and in some circumstances
231 	 * syslogd may have trouble keeping up, so keep it BRIEF rather than user-friendly.
232 	 */
233 	vdo_dump_completion_to_buffer(&data_vio->vio.completion,
234 				      vio_completion_dump_buffer,
235 				      sizeof(vio_completion_dump_buffer));
236 	if (data_vio->is_duplicate) {
237 		snprintf(vio_block_number_dump_buffer,
238 			 sizeof(vio_block_number_dump_buffer), "P%llu L%llu D%llu",
239 			 data_vio->allocation.pbn, data_vio->logical.lbn,
240 			 data_vio->duplicate.pbn);
241 	} else if (data_vio_has_allocation(data_vio)) {
242 		snprintf(vio_block_number_dump_buffer,
243 			 sizeof(vio_block_number_dump_buffer), "P%llu L%llu",
244 			 data_vio->allocation.pbn, data_vio->logical.lbn);
245 	} else {
246 		snprintf(vio_block_number_dump_buffer,
247 			 sizeof(vio_block_number_dump_buffer), "L%llu",
248 			 data_vio->logical.lbn);
249 	}
250 
251 	if (data_vio->flush_generation != 0) {
252 		snprintf(vio_flush_generation_buffer,
253 			 sizeof(vio_flush_generation_buffer), " FG%llu",
254 			 data_vio->flush_generation);
255 	} else {
256 		vio_flush_generation_buffer[0] = 0;
257 	}
258 
259 	encode_vio_dump_flags(data_vio, flags_dump_buffer);
260 
261 	vdo_log_info("	vio %px %s%s %s %s%s", data_vio,
262 		     vio_block_number_dump_buffer,
263 		     vio_flush_generation_buffer,
264 		     get_data_vio_operation_name(data_vio),
265 		     vio_completion_dump_buffer,
266 		     flags_dump_buffer);
267 	/*
268 	 * might want info on: wantUDSAnswer / operation / status
269 	 * might want info on: bio / bios_merged
270 	 */
271 
272 	dump_vio_waiters(&data_vio->logical.waiters, "lbn");
273 
274 	/* might want to dump more info from vio here */
275 }
276