error: Eliminate error_propagate() with Coccinelle, part 2
[qemu.git] / block / blklogwrites.c
1 /*
2 * Write logging blk driver based on blkverify and blkdebug.
3 *
4 * Copyright (c) 2017 Tuomas Tynkkynen <tuomas@tuxera.com>
5 * Copyright (c) 2018 Aapo Vienamo <aapo@tuxera.com>
6 * Copyright (c) 2018 Ari Sundholm <ari@tuxera.com>
7 *
8 * This work is licensed under the terms of the GNU GPL, version 2 or later.
9 * See the COPYING file in the top-level directory.
10 */
11
12 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "qemu/sockets.h" /* for EINPROGRESS on Windows */
15 #include "block/block_int.h"
16 #include "qapi/qmp/qdict.h"
17 #include "qapi/qmp/qstring.h"
18 #include "qemu/cutils.h"
19 #include "qemu/module.h"
20 #include "qemu/option.h"
21
22 /* Disk format stuff - taken from Linux drivers/md/dm-log-writes.c */
23
24 #define LOG_FLUSH_FLAG (1 << 0)
25 #define LOG_FUA_FLAG (1 << 1)
26 #define LOG_DISCARD_FLAG (1 << 2)
27 #define LOG_MARK_FLAG (1 << 3)
28 #define LOG_FLAG_MASK (LOG_FLUSH_FLAG \
29 | LOG_FUA_FLAG \
30 | LOG_DISCARD_FLAG \
31 | LOG_MARK_FLAG)
32
33 #define WRITE_LOG_VERSION 1ULL
34 #define WRITE_LOG_MAGIC 0x6a736677736872ULL
35
36 /* All fields are little-endian. */
37 struct log_write_super {
38 uint64_t magic;
39 uint64_t version;
40 uint64_t nr_entries;
41 uint32_t sectorsize;
42 } QEMU_PACKED;
43
44 struct log_write_entry {
45 uint64_t sector;
46 uint64_t nr_sectors;
47 uint64_t flags;
48 uint64_t data_len;
49 } QEMU_PACKED;
50
51 /* End of disk format structures. */
52
53 typedef struct {
54 BdrvChild *log_file;
55 uint32_t sectorsize;
56 uint32_t sectorbits;
57 uint64_t cur_log_sector;
58 uint64_t nr_entries;
59 uint64_t update_interval;
60 } BDRVBlkLogWritesState;
61
62 static QemuOptsList runtime_opts = {
63 .name = "blklogwrites",
64 .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
65 .desc = {
66 {
67 .name = "log-append",
68 .type = QEMU_OPT_BOOL,
69 .help = "Append to an existing log",
70 },
71 {
72 .name = "log-sector-size",
73 .type = QEMU_OPT_SIZE,
74 .help = "Log sector size",
75 },
76 {
77 .name = "log-super-update-interval",
78 .type = QEMU_OPT_NUMBER,
79 .help = "Log superblock update interval (# of write requests)",
80 },
81 { /* end of list */ }
82 },
83 };
84
85 static inline uint32_t blk_log_writes_log2(uint32_t value)
86 {
87 assert(value > 0);
88 return 31 - clz32(value);
89 }
90
91 static inline bool blk_log_writes_sector_size_valid(uint32_t sector_size)
92 {
93 return is_power_of_2(sector_size) &&
94 sector_size >= sizeof(struct log_write_super) &&
95 sector_size >= sizeof(struct log_write_entry) &&
96 sector_size < (1ull << 24);
97 }
98
99 static uint64_t blk_log_writes_find_cur_log_sector(BdrvChild *log,
100 uint32_t sector_size,
101 uint64_t nr_entries,
102 Error **errp)
103 {
104 uint64_t cur_sector = 1;
105 uint64_t cur_idx = 0;
106 uint32_t sector_bits = blk_log_writes_log2(sector_size);
107 struct log_write_entry cur_entry;
108
109 while (cur_idx < nr_entries) {
110 int read_ret = bdrv_pread(log, cur_sector << sector_bits, &cur_entry,
111 sizeof(cur_entry));
112 if (read_ret < 0) {
113 error_setg_errno(errp, -read_ret,
114 "Failed to read log entry %"PRIu64, cur_idx);
115 return (uint64_t)-1ull;
116 }
117
118 if (cur_entry.flags & ~cpu_to_le64(LOG_FLAG_MASK)) {
119 error_setg(errp, "Invalid flags 0x%"PRIx64" in log entry %"PRIu64,
120 le64_to_cpu(cur_entry.flags), cur_idx);
121 return (uint64_t)-1ull;
122 }
123
124 /* Account for the sector of the entry itself */
125 ++cur_sector;
126
127 /*
128 * Account for the data of the write.
129 * For discards, this data is not present.
130 */
131 if (!(cur_entry.flags & cpu_to_le64(LOG_DISCARD_FLAG))) {
132 cur_sector += le64_to_cpu(cur_entry.nr_sectors);
133 }
134
135 ++cur_idx;
136 }
137
138 return cur_sector;
139 }
140
141 static int blk_log_writes_open(BlockDriverState *bs, QDict *options, int flags,
142 Error **errp)
143 {
144 BDRVBlkLogWritesState *s = bs->opaque;
145 QemuOpts *opts;
146 Error *local_err = NULL;
147 int ret;
148 uint64_t log_sector_size;
149 bool log_append;
150
151 opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
152 if (!qemu_opts_absorb_qdict(opts, options, errp)) {
153 ret = -EINVAL;
154 goto fail;
155 }
156
157 /* Open the file */
158 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
159 BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, false,
160 &local_err);
161 if (local_err) {
162 ret = -EINVAL;
163 error_propagate(errp, local_err);
164 goto fail;
165 }
166
167 /* Open the log file */
168 s->log_file = bdrv_open_child(NULL, options, "log", bs, &child_of_bds,
169 BDRV_CHILD_METADATA, false, &local_err);
170 if (local_err) {
171 ret = -EINVAL;
172 error_propagate(errp, local_err);
173 goto fail;
174 }
175
176 log_append = qemu_opt_get_bool(opts, "log-append", false);
177
178 if (log_append) {
179 struct log_write_super log_sb = { 0, 0, 0, 0 };
180
181 if (qemu_opt_find(opts, "log-sector-size")) {
182 ret = -EINVAL;
183 error_setg(errp, "log-append and log-sector-size are mutually "
184 "exclusive");
185 goto fail_log;
186 }
187
188 /* Read log superblock or fake one for an empty log */
189 if (!bdrv_getlength(s->log_file->bs)) {
190 log_sb.magic = cpu_to_le64(WRITE_LOG_MAGIC);
191 log_sb.version = cpu_to_le64(WRITE_LOG_VERSION);
192 log_sb.nr_entries = cpu_to_le64(0);
193 log_sb.sectorsize = cpu_to_le32(BDRV_SECTOR_SIZE);
194 } else {
195 ret = bdrv_pread(s->log_file, 0, &log_sb, sizeof(log_sb));
196 if (ret < 0) {
197 error_setg_errno(errp, -ret, "Could not read log superblock");
198 goto fail_log;
199 }
200 }
201
202 if (log_sb.magic != cpu_to_le64(WRITE_LOG_MAGIC)) {
203 ret = -EINVAL;
204 error_setg(errp, "Invalid log superblock magic");
205 goto fail_log;
206 }
207
208 if (log_sb.version != cpu_to_le64(WRITE_LOG_VERSION)) {
209 ret = -EINVAL;
210 error_setg(errp, "Unsupported log version %"PRIu64,
211 le64_to_cpu(log_sb.version));
212 goto fail_log;
213 }
214
215 log_sector_size = le32_to_cpu(log_sb.sectorsize);
216 s->cur_log_sector = 1;
217 s->nr_entries = 0;
218
219 if (blk_log_writes_sector_size_valid(log_sector_size)) {
220 s->cur_log_sector =
221 blk_log_writes_find_cur_log_sector(s->log_file, log_sector_size,
222 le64_to_cpu(log_sb.nr_entries), &local_err);
223 if (local_err) {
224 ret = -EINVAL;
225 error_propagate(errp, local_err);
226 goto fail_log;
227 }
228
229 s->nr_entries = le64_to_cpu(log_sb.nr_entries);
230 }
231 } else {
232 log_sector_size = qemu_opt_get_size(opts, "log-sector-size",
233 BDRV_SECTOR_SIZE);
234 s->cur_log_sector = 1;
235 s->nr_entries = 0;
236 }
237
238 if (!blk_log_writes_sector_size_valid(log_sector_size)) {
239 ret = -EINVAL;
240 error_setg(errp, "Invalid log sector size %"PRIu64, log_sector_size);
241 goto fail_log;
242 }
243
244 s->sectorsize = log_sector_size;
245 s->sectorbits = blk_log_writes_log2(log_sector_size);
246 s->update_interval = qemu_opt_get_number(opts, "log-super-update-interval",
247 4096);
248 if (!s->update_interval) {
249 ret = -EINVAL;
250 error_setg(errp, "Invalid log superblock update interval %"PRIu64,
251 s->update_interval);
252 goto fail_log;
253 }
254
255 ret = 0;
256 fail_log:
257 if (ret < 0) {
258 bdrv_unref_child(bs, s->log_file);
259 s->log_file = NULL;
260 }
261 fail:
262 if (ret < 0) {
263 bdrv_unref_child(bs, bs->file);
264 bs->file = NULL;
265 }
266 qemu_opts_del(opts);
267 return ret;
268 }
269
270 static void blk_log_writes_close(BlockDriverState *bs)
271 {
272 BDRVBlkLogWritesState *s = bs->opaque;
273
274 bdrv_unref_child(bs, s->log_file);
275 s->log_file = NULL;
276 }
277
278 static int64_t blk_log_writes_getlength(BlockDriverState *bs)
279 {
280 return bdrv_getlength(bs->file->bs);
281 }
282
283 static void blk_log_writes_child_perm(BlockDriverState *bs, BdrvChild *c,
284 BdrvChildRole role,
285 BlockReopenQueue *ro_q,
286 uint64_t perm, uint64_t shrd,
287 uint64_t *nperm, uint64_t *nshrd)
288 {
289 if (!c) {
290 *nperm = perm & DEFAULT_PERM_PASSTHROUGH;
291 *nshrd = (shrd & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
292 return;
293 }
294
295 bdrv_default_perms(bs, c, role, ro_q, perm, shrd,
296 nperm, nshrd);
297 }
298
299 static void blk_log_writes_refresh_limits(BlockDriverState *bs, Error **errp)
300 {
301 BDRVBlkLogWritesState *s = bs->opaque;
302 bs->bl.request_alignment = s->sectorsize;
303 }
304
305 static int coroutine_fn
306 blk_log_writes_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
307 QEMUIOVector *qiov, int flags)
308 {
309 return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
310 }
311
312 typedef struct BlkLogWritesFileReq {
313 BlockDriverState *bs;
314 uint64_t offset;
315 uint64_t bytes;
316 int file_flags;
317 QEMUIOVector *qiov;
318 int (*func)(struct BlkLogWritesFileReq *r);
319 int file_ret;
320 } BlkLogWritesFileReq;
321
322 typedef struct {
323 BlockDriverState *bs;
324 QEMUIOVector *qiov;
325 struct log_write_entry entry;
326 uint64_t zero_size;
327 int log_ret;
328 } BlkLogWritesLogReq;
329
330 static void coroutine_fn blk_log_writes_co_do_log(BlkLogWritesLogReq *lr)
331 {
332 BDRVBlkLogWritesState *s = lr->bs->opaque;
333 uint64_t cur_log_offset = s->cur_log_sector << s->sectorbits;
334
335 s->nr_entries++;
336 s->cur_log_sector +=
337 ROUND_UP(lr->qiov->size, s->sectorsize) >> s->sectorbits;
338
339 lr->log_ret = bdrv_co_pwritev(s->log_file, cur_log_offset, lr->qiov->size,
340 lr->qiov, 0);
341
342 /* Logging for the "write zeroes" operation */
343 if (lr->log_ret == 0 && lr->zero_size) {
344 cur_log_offset = s->cur_log_sector << s->sectorbits;
345 s->cur_log_sector +=
346 ROUND_UP(lr->zero_size, s->sectorsize) >> s->sectorbits;
347
348 lr->log_ret = bdrv_co_pwrite_zeroes(s->log_file, cur_log_offset,
349 lr->zero_size, 0);
350 }
351
352 /* Update super block on flush or every update interval */
353 if (lr->log_ret == 0 && ((lr->entry.flags & LOG_FLUSH_FLAG)
354 || (s->nr_entries % s->update_interval == 0)))
355 {
356 struct log_write_super super = {
357 .magic = cpu_to_le64(WRITE_LOG_MAGIC),
358 .version = cpu_to_le64(WRITE_LOG_VERSION),
359 .nr_entries = cpu_to_le64(s->nr_entries),
360 .sectorsize = cpu_to_le32(s->sectorsize),
361 };
362 void *zeroes = g_malloc0(s->sectorsize - sizeof(super));
363 QEMUIOVector qiov;
364
365 qemu_iovec_init(&qiov, 2);
366 qemu_iovec_add(&qiov, &super, sizeof(super));
367 qemu_iovec_add(&qiov, zeroes, s->sectorsize - sizeof(super));
368
369 lr->log_ret =
370 bdrv_co_pwritev(s->log_file, 0, s->sectorsize, &qiov, 0);
371 if (lr->log_ret == 0) {
372 lr->log_ret = bdrv_co_flush(s->log_file->bs);
373 }
374 qemu_iovec_destroy(&qiov);
375 g_free(zeroes);
376 }
377 }
378
379 static void coroutine_fn blk_log_writes_co_do_file(BlkLogWritesFileReq *fr)
380 {
381 fr->file_ret = fr->func(fr);
382 }
383
384 static int coroutine_fn
385 blk_log_writes_co_log(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
386 QEMUIOVector *qiov, int flags,
387 int (*file_func)(BlkLogWritesFileReq *r),
388 uint64_t entry_flags, bool is_zero_write)
389 {
390 QEMUIOVector log_qiov;
391 size_t niov = qiov ? qiov->niov : 0;
392 BDRVBlkLogWritesState *s = bs->opaque;
393 BlkLogWritesFileReq fr = {
394 .bs = bs,
395 .offset = offset,
396 .bytes = bytes,
397 .file_flags = flags,
398 .qiov = qiov,
399 .func = file_func,
400 };
401 BlkLogWritesLogReq lr = {
402 .bs = bs,
403 .qiov = &log_qiov,
404 .entry = {
405 .sector = cpu_to_le64(offset >> s->sectorbits),
406 .nr_sectors = cpu_to_le64(bytes >> s->sectorbits),
407 .flags = cpu_to_le64(entry_flags),
408 .data_len = 0,
409 },
410 .zero_size = is_zero_write ? bytes : 0,
411 };
412 void *zeroes = g_malloc0(s->sectorsize - sizeof(lr.entry));
413
414 assert((1 << s->sectorbits) == s->sectorsize);
415 assert(bs->bl.request_alignment == s->sectorsize);
416 assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
417 assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
418
419 qemu_iovec_init(&log_qiov, niov + 2);
420 qemu_iovec_add(&log_qiov, &lr.entry, sizeof(lr.entry));
421 qemu_iovec_add(&log_qiov, zeroes, s->sectorsize - sizeof(lr.entry));
422 if (qiov) {
423 qemu_iovec_concat(&log_qiov, qiov, 0, qiov->size);
424 }
425
426 blk_log_writes_co_do_file(&fr);
427 blk_log_writes_co_do_log(&lr);
428
429 qemu_iovec_destroy(&log_qiov);
430 g_free(zeroes);
431
432 if (lr.log_ret < 0) {
433 return lr.log_ret;
434 }
435
436 return fr.file_ret;
437 }
438
439 static int coroutine_fn
440 blk_log_writes_co_do_file_pwritev(BlkLogWritesFileReq *fr)
441 {
442 return bdrv_co_pwritev(fr->bs->file, fr->offset, fr->bytes,
443 fr->qiov, fr->file_flags);
444 }
445
446 static int coroutine_fn
447 blk_log_writes_co_do_file_pwrite_zeroes(BlkLogWritesFileReq *fr)
448 {
449 return bdrv_co_pwrite_zeroes(fr->bs->file, fr->offset, fr->bytes,
450 fr->file_flags);
451 }
452
453 static int coroutine_fn blk_log_writes_co_do_file_flush(BlkLogWritesFileReq *fr)
454 {
455 return bdrv_co_flush(fr->bs->file->bs);
456 }
457
458 static int coroutine_fn
459 blk_log_writes_co_do_file_pdiscard(BlkLogWritesFileReq *fr)
460 {
461 return bdrv_co_pdiscard(fr->bs->file, fr->offset, fr->bytes);
462 }
463
464 static int coroutine_fn
465 blk_log_writes_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
466 QEMUIOVector *qiov, int flags)
467 {
468 return blk_log_writes_co_log(bs, offset, bytes, qiov, flags,
469 blk_log_writes_co_do_file_pwritev, 0, false);
470 }
471
472 static int coroutine_fn
473 blk_log_writes_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
474 BdrvRequestFlags flags)
475 {
476 return blk_log_writes_co_log(bs, offset, bytes, NULL, flags,
477 blk_log_writes_co_do_file_pwrite_zeroes, 0,
478 true);
479 }
480
481 static int coroutine_fn blk_log_writes_co_flush_to_disk(BlockDriverState *bs)
482 {
483 return blk_log_writes_co_log(bs, 0, 0, NULL, 0,
484 blk_log_writes_co_do_file_flush,
485 LOG_FLUSH_FLAG, false);
486 }
487
488 static int coroutine_fn
489 blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
490 {
491 return blk_log_writes_co_log(bs, offset, count, NULL, 0,
492 blk_log_writes_co_do_file_pdiscard,
493 LOG_DISCARD_FLAG, false);
494 }
495
496 static const char *const blk_log_writes_strong_runtime_opts[] = {
497 "log-append",
498 "log-sector-size",
499
500 NULL
501 };
502
503 static BlockDriver bdrv_blk_log_writes = {
504 .format_name = "blklogwrites",
505 .instance_size = sizeof(BDRVBlkLogWritesState),
506
507 .bdrv_open = blk_log_writes_open,
508 .bdrv_close = blk_log_writes_close,
509 .bdrv_getlength = blk_log_writes_getlength,
510 .bdrv_child_perm = blk_log_writes_child_perm,
511 .bdrv_refresh_limits = blk_log_writes_refresh_limits,
512
513 .bdrv_co_preadv = blk_log_writes_co_preadv,
514 .bdrv_co_pwritev = blk_log_writes_co_pwritev,
515 .bdrv_co_pwrite_zeroes = blk_log_writes_co_pwrite_zeroes,
516 .bdrv_co_flush_to_disk = blk_log_writes_co_flush_to_disk,
517 .bdrv_co_pdiscard = blk_log_writes_co_pdiscard,
518 .bdrv_co_block_status = bdrv_co_block_status_from_file,
519
520 .is_filter = true,
521 .strong_runtime_opts = blk_log_writes_strong_runtime_opts,
522 };
523
524 static void bdrv_blk_log_writes_init(void)
525 {
526 bdrv_register(&bdrv_blk_log_writes);
527 }
528
529 block_init(bdrv_blk_log_writes_init);