block/blkverify.c

   1 /*
   2  * Block protocol for block driver correctness testing
   3  *
   4  * Copyright (C) 2010 IBM, Corp.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  */
   9
  10 #include <stdarg.h>
  11 #include "qemu/sockets.h" /* for EINPROGRESS on Windows */
  12 #include "block/block_int.h"
  13
  14 typedef struct {
  15     BlockDriverState *test_file;
  16 } BDRVBlkverifyState;
  17
  18 typedef struct BlkverifyAIOCB BlkverifyAIOCB;
  19 struct BlkverifyAIOCB {
  20     BlockDriverAIOCB common;
  21     QEMUBH *bh;
  22
  23     /* Request metadata */
  24     bool is_write;
  25     int64_t sector_num;
  26     int nb_sectors;
  27
  28     int ret;                    /* first completed request's result */
  29     unsigned int done;          /* completion counter */
  30     bool *finished;             /* completion signal for cancel */
  31
  32     QEMUIOVector *qiov;         /* user I/O vector */
  33     QEMUIOVector raw_qiov;      /* cloned I/O vector for raw file */
  34     void *buf;                  /* buffer for raw file I/O */
  35
  36     void (*verify)(BlkverifyAIOCB *acb);
  37 };
  38
  39 static void blkverify_aio_cancel(BlockDriverAIOCB *blockacb)
  40 {
  41     BlkverifyAIOCB *acb = (BlkverifyAIOCB *)blockacb;
  42     bool finished = false;
  43
  44     /* Wait until request completes, invokes its callback, and frees itself */
  45     acb->finished = &finished;
  46     while (!finished) {
  47         qemu_aio_wait();
  48     }
  49 }
  50
  51 static const AIOCBInfo blkverify_aiocb_info = {
  52     .aiocb_size         = sizeof(BlkverifyAIOCB),
  53     .cancel             = blkverify_aio_cancel,
  54 };
  55
  56 static void GCC_FMT_ATTR(2, 3) blkverify_err(BlkverifyAIOCB *acb,
  57                                              const char *fmt, ...)
  58 {
  59     va_list ap;
  60
  61     va_start(ap, fmt);
  62     fprintf(stderr, "blkverify: %s sector_num=%" PRId64 " nb_sectors=%d ",
  63             acb->is_write ? "write" : "read", acb->sector_num,
  64             acb->nb_sectors);
  65     vfprintf(stderr, fmt, ap);
  66     fprintf(stderr, "\n");
  67     va_end(ap);
  68     exit(1);
  69 }
  70
  71 /* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */
  72 static void blkverify_parse_filename(const char *filename, QDict *options,
  73                                      Error **errp)
  74 {
  75     const char *c;
  76     QString *raw_path;
  77
  78
  79     /* Parse the blkverify: prefix */
  80     if (!strstart(filename, "blkverify:", &filename)) {
  81         /* There was no prefix; therefore, all options have to be already
  82            present in the QDict (except for the filename) */
  83         qdict_put(options, "x-image", qstring_from_str(filename));
  84         return;
  85     }
  86
  87     /* Parse the raw image filename */
  88     c = strchr(filename, ':');
  89     if (c == NULL) {
  90         error_setg(errp, "blkverify requires raw copy and original image path");
  91         return;
  92     }
  93
  94     /* TODO Implement option pass-through and set raw.filename here */
  95     raw_path = qstring_from_substr(filename, 0, c - filename - 1);
  96     qdict_put(options, "x-raw", raw_path);
  97
  98     /* TODO Allow multi-level nesting and set file.filename here */
  99     filename = c + 1;
 100     qdict_put(options, "x-image", qstring_from_str(filename));
 101 }
 102
 103 static QemuOptsList runtime_opts = {
 104     .name = "blkverify",
 105     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 106     .desc = {
 107         {
 108             .name = "x-raw",
 109             .type = QEMU_OPT_STRING,
 110             .help = "[internal use only, will be removed]",
 111         },
 112         {
 113             .name = "x-image",
 114             .type = QEMU_OPT_STRING,
 115             .help = "[internal use only, will be removed]",
 116         },
 117         { /* end of list */ }
 118     },
 119 };
 120
 121 static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
 122                           Error **errp)
 123 {
 124     BDRVBlkverifyState *s = bs->opaque;
 125     QemuOpts *opts;
 126     Error *local_err = NULL;
 127     int ret;
 128
 129     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 130     qemu_opts_absorb_qdict(opts, options, &local_err);
 131     if (local_err) {
 132         error_propagate(errp, local_err);
 133         ret = -EINVAL;
 134         goto fail;
 135     }
 136
 137     /* Open the raw file */
 138     ret = bdrv_open_image(&bs->file, qemu_opt_get(opts, "x-raw"), options,
 139                           "raw", flags, true, false, &local_err);
 140     if (ret < 0) {
 141         error_propagate(errp, local_err);
 142         goto fail;
 143     }
 144
 145     /* Open the test file */
 146     ret = bdrv_open_image(&s->test_file, qemu_opt_get(opts, "x-image"), options,
 147                           "test", flags, false, false, &local_err);
 148     if (ret < 0) {
 149         error_propagate(errp, local_err);
 150         s->test_file = NULL;
 151         goto fail;
 152     }
 153
 154     ret = 0;
 155 fail:
 156     return ret;
 157 }
 158
 159 static void blkverify_close(BlockDriverState *bs)
 160 {
 161     BDRVBlkverifyState *s = bs->opaque;
 162
 163     bdrv_unref(s->test_file);
 164     s->test_file = NULL;
 165 }
 166
 167 static int64_t blkverify_getlength(BlockDriverState *bs)
 168 {
 169     BDRVBlkverifyState *s = bs->opaque;
 170
 171     return bdrv_getlength(s->test_file);
 172 }
 173
 174 /**
 175  * Check that I/O vector contents are identical
 176  *
 177  * @a:          I/O vector
 178  * @b:          I/O vector
 179  * @ret:        Offset to first mismatching byte or -1 if match
 180  */
 181 static ssize_t blkverify_iovec_compare(QEMUIOVector *a, QEMUIOVector *b)
 182 {
 183     int i;
 184     ssize_t offset = 0;
 185
 186     assert(a->niov == b->niov);
 187     for (i = 0; i < a->niov; i++) {
 188         size_t len = 0;
 189         uint8_t *p = (uint8_t *)a->iov[i].iov_base;
 190         uint8_t *q = (uint8_t *)b->iov[i].iov_base;
 191
 192         assert(a->iov[i].iov_len == b->iov[i].iov_len);
 193         while (len < a->iov[i].iov_len && *p++ == *q++) {
 194             len++;
 195         }
 196
 197         offset += len;
 198
 199         if (len != a->iov[i].iov_len) {
 200             return offset;
 201         }
 202     }
 203     return -1;
 204 }
 205
 206 typedef struct {
 207     int src_index;
 208     struct iovec *src_iov;
 209     void *dest_base;
 210 } IOVectorSortElem;
 211
 212 static int sortelem_cmp_src_base(const void *a, const void *b)
 213 {
 214     const IOVectorSortElem *elem_a = a;
 215     const IOVectorSortElem *elem_b = b;
 216
 217     /* Don't overflow */
 218     if (elem_a->src_iov->iov_base < elem_b->src_iov->iov_base) {
 219         return -1;
 220     } else if (elem_a->src_iov->iov_base > elem_b->src_iov->iov_base) {
 221         return 1;
 222     } else {
 223         return 0;
 224     }
 225 }
 226
 227 static int sortelem_cmp_src_index(const void *a, const void *b)
 228 {
 229     const IOVectorSortElem *elem_a = a;
 230     const IOVectorSortElem *elem_b = b;
 231
 232     return elem_a->src_index - elem_b->src_index;
 233 }
 234
 235 /**
 236  * Copy contents of I/O vector
 237  *
 238  * The relative relationships of overlapping iovecs are preserved.  This is
 239  * necessary to ensure identical semantics in the cloned I/O vector.
 240  */
 241 static void blkverify_iovec_clone(QEMUIOVector *dest, const QEMUIOVector *src,
 242                                   void *buf)
 243 {
 244     IOVectorSortElem sortelems[src->niov];
 245     void *last_end;
 246     int i;
 247
 248     /* Sort by source iovecs by base address */
 249     for (i = 0; i < src->niov; i++) {
 250         sortelems[i].src_index = i;
 251         sortelems[i].src_iov = &src->iov[i];
 252     }
 253     qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_base);
 254
 255     /* Allocate buffer space taking into account overlapping iovecs */
 256     last_end = NULL;
 257     for (i = 0; i < src->niov; i++) {
 258         struct iovec *cur = sortelems[i].src_iov;
 259         ptrdiff_t rewind = 0;
 260
 261         /* Detect overlap */
 262         if (last_end && last_end > cur->iov_base) {
 263             rewind = last_end - cur->iov_base;
 264         }
 265
 266         sortelems[i].dest_base = buf - rewind;
 267         buf += cur->iov_len - MIN(rewind, cur->iov_len);
 268         last_end = MAX(cur->iov_base + cur->iov_len, last_end);
 269     }
 270
 271     /* Sort by source iovec index and build destination iovec */
 272     qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_index);
 273     for (i = 0; i < src->niov; i++) {
 274         qemu_iovec_add(dest, sortelems[i].dest_base, src->iov[i].iov_len);
 275     }
 276 }
 277
 278 static BlkverifyAIOCB *blkverify_aio_get(BlockDriverState *bs, bool is_write,
 279                                          int64_t sector_num, QEMUIOVector *qiov,
 280                                          int nb_sectors,
 281                                          BlockDriverCompletionFunc *cb,
 282                                          void *opaque)
 283 {
 284     BlkverifyAIOCB *acb = qemu_aio_get(&blkverify_aiocb_info, bs, cb, opaque);
 285
 286     acb->bh = NULL;
 287     acb->is_write = is_write;
 288     acb->sector_num = sector_num;
 289     acb->nb_sectors = nb_sectors;
 290     acb->ret = -EINPROGRESS;
 291     acb->done = 0;
 292     acb->qiov = qiov;
 293     acb->buf = NULL;
 294     acb->verify = NULL;
 295     acb->finished = NULL;
 296     return acb;
 297 }
 298
 299 static void blkverify_aio_bh(void *opaque)
 300 {
 301     BlkverifyAIOCB *acb = opaque;
 302
 303     qemu_bh_delete(acb->bh);
 304     if (acb->buf) {
 305         qemu_iovec_destroy(&acb->raw_qiov);
 306         qemu_vfree(acb->buf);
 307     }
 308     acb->common.cb(acb->common.opaque, acb->ret);
 309     if (acb->finished) {
 310         *acb->finished = true;
 311     }
 312     qemu_aio_release(acb);
 313 }
 314
 315 static void blkverify_aio_cb(void *opaque, int ret)
 316 {
 317     BlkverifyAIOCB *acb = opaque;
 318
 319     switch (++acb->done) {
 320     case 1:
 321         acb->ret = ret;
 322         break;
 323
 324     case 2:
 325         if (acb->ret != ret) {
 326             blkverify_err(acb, "return value mismatch %d != %d", acb->ret, ret);
 327         }
 328
 329         if (acb->verify) {
 330             acb->verify(acb);
 331         }
 332
 333         acb->bh = qemu_bh_new(blkverify_aio_bh, acb);
 334         qemu_bh_schedule(acb->bh);
 335         break;
 336     }
 337 }
 338
 339 static void blkverify_verify_readv(BlkverifyAIOCB *acb)
 340 {
 341     ssize_t offset = blkverify_iovec_compare(acb->qiov, &acb->raw_qiov);
 342     if (offset != -1) {
 343         blkverify_err(acb, "contents mismatch in sector %" PRId64,
 344                       acb->sector_num + (int64_t)(offset / BDRV_SECTOR_SIZE));
 345     }
 346 }
 347
 348 static BlockDriverAIOCB *blkverify_aio_readv(BlockDriverState *bs,
 349         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 350         BlockDriverCompletionFunc *cb, void *opaque)
 351 {
 352     BDRVBlkverifyState *s = bs->opaque;
 353     BlkverifyAIOCB *acb = blkverify_aio_get(bs, false, sector_num, qiov,
 354                                             nb_sectors, cb, opaque);
 355
 356     acb->verify = blkverify_verify_readv;
 357     acb->buf = qemu_blockalign(bs->file, qiov->size);
 358     qemu_iovec_init(&acb->raw_qiov, acb->qiov->niov);
 359     blkverify_iovec_clone(&acb->raw_qiov, qiov, acb->buf);
 360
 361     bdrv_aio_readv(s->test_file, sector_num, qiov, nb_sectors,
 362                    blkverify_aio_cb, acb);
 363     bdrv_aio_readv(bs->file, sector_num, &acb->raw_qiov, nb_sectors,
 364                    blkverify_aio_cb, acb);
 365     return &acb->common;
 366 }
 367
 368 static BlockDriverAIOCB *blkverify_aio_writev(BlockDriverState *bs,
 369         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 370         BlockDriverCompletionFunc *cb, void *opaque)
 371 {
 372     BDRVBlkverifyState *s = bs->opaque;
 373     BlkverifyAIOCB *acb = blkverify_aio_get(bs, true, sector_num, qiov,
 374                                             nb_sectors, cb, opaque);
 375
 376     bdrv_aio_writev(s->test_file, sector_num, qiov, nb_sectors,
 377                     blkverify_aio_cb, acb);
 378     bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors,
 379                     blkverify_aio_cb, acb);
 380     return &acb->common;
 381 }
 382
 383 static BlockDriverAIOCB *blkverify_aio_flush(BlockDriverState *bs,
 384                                              BlockDriverCompletionFunc *cb,
 385                                              void *opaque)
 386 {
 387     BDRVBlkverifyState *s = bs->opaque;
 388
 389     /* Only flush test file, the raw file is not important */
 390     return bdrv_aio_flush(s->test_file, cb, opaque);
 391 }
 392
 393 static BlockDriver bdrv_blkverify = {
 394     .format_name            = "blkverify",
 395     .protocol_name          = "blkverify",
 396     .instance_size          = sizeof(BDRVBlkverifyState),
 397
 398     .bdrv_parse_filename    = blkverify_parse_filename,
 399     .bdrv_file_open         = blkverify_open,
 400     .bdrv_close             = blkverify_close,
 401     .bdrv_getlength         = blkverify_getlength,
 402
 403     .bdrv_aio_readv         = blkverify_aio_readv,
 404     .bdrv_aio_writev        = blkverify_aio_writev,
 405     .bdrv_aio_flush         = blkverify_aio_flush,
 406
 407     .authorizations         = { true, false },
 408 };
 409
 410 static void bdrv_blkverify_init(void)
 411 {
 412     bdrv_register(&bdrv_blkverify);
 413 }
 414
 415 block_init(bdrv_blkverify_init);