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         error_setg(errp, "File name string must start with 'blkverify:'");
  82         return;
  83     }
  84
  85     /* Parse the raw image filename */
  86     c = strchr(filename, ':');
  87     if (c == NULL) {
  88         error_setg(errp, "blkverify requires raw copy and original image path");
  89         return;
  90     }
  91
  92     /* TODO Implement option pass-through and set raw.filename here */
  93     raw_path = qstring_from_substr(filename, 0, c - filename - 1);
  94     qdict_put(options, "x-raw", raw_path);
  95
  96     /* TODO Allow multi-level nesting and set file.filename here */
  97     filename = c + 1;
  98     qdict_put(options, "x-image", qstring_from_str(filename));
  99 }
 100
 101 static QemuOptsList runtime_opts = {
 102     .name = "blkverify",
 103     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 104     .desc = {
 105         {
 106             .name = "x-raw",
 107             .type = QEMU_OPT_STRING,
 108             .help = "[internal use only, will be removed]",
 109         },
 110         {
 111             .name = "x-image",
 112             .type = QEMU_OPT_STRING,
 113             .help = "[internal use only, will be removed]",
 114         },
 115         { /* end of list */ }
 116     },
 117 };
 118
 119 static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
 120                           Error **errp)
 121 {
 122     BDRVBlkverifyState *s = bs->opaque;
 123     QemuOpts *opts;
 124     Error *local_err = NULL;
 125     const char *filename, *raw;
 126     int ret;
 127
 128     opts = qemu_opts_create_nofail(&runtime_opts);
 129     qemu_opts_absorb_qdict(opts, options, &local_err);
 130     if (error_is_set(&local_err)) {
 131         qerror_report_err(local_err);
 132         error_free(local_err);
 133         ret = -EINVAL;
 134         goto fail;
 135     }
 136
 137     /* Parse the raw image filename */
 138     raw = qemu_opt_get(opts, "x-raw");
 139     if (raw == NULL) {
 140         ret = -EINVAL;
 141         goto fail;
 142     }
 143
 144     ret = bdrv_file_open(&bs->file, raw, NULL, flags);
 145     if (ret < 0) {
 146         goto fail;
 147     }
 148
 149     /* Open the test file */
 150     filename = qemu_opt_get(opts, "x-image");
 151     if (filename == NULL) {
 152         ret = -EINVAL;
 153         goto fail;
 154     }
 155
 156     s->test_file = bdrv_new("");
 157     ret = bdrv_open(s->test_file, filename, NULL, flags, NULL);
 158     if (ret < 0) {
 159         bdrv_unref(s->test_file);
 160         s->test_file = NULL;
 161         goto fail;
 162     }
 163
 164     ret = 0;
 165 fail:
 166     return ret;
 167 }
 168
 169 static void blkverify_close(BlockDriverState *bs)
 170 {
 171     BDRVBlkverifyState *s = bs->opaque;
 172
 173     bdrv_unref(s->test_file);
 174     s->test_file = NULL;
 175 }
 176
 177 static int64_t blkverify_getlength(BlockDriverState *bs)
 178 {
 179     BDRVBlkverifyState *s = bs->opaque;
 180
 181     return bdrv_getlength(s->test_file);
 182 }
 183
 184 /**
 185  * Check that I/O vector contents are identical
 186  *
 187  * @a:          I/O vector
 188  * @b:          I/O vector
 189  * @ret:        Offset to first mismatching byte or -1 if match
 190  */
 191 static ssize_t blkverify_iovec_compare(QEMUIOVector *a, QEMUIOVector *b)
 192 {
 193     int i;
 194     ssize_t offset = 0;
 195
 196     assert(a->niov == b->niov);
 197     for (i = 0; i < a->niov; i++) {
 198         size_t len = 0;
 199         uint8_t *p = (uint8_t *)a->iov[i].iov_base;
 200         uint8_t *q = (uint8_t *)b->iov[i].iov_base;
 201
 202         assert(a->iov[i].iov_len == b->iov[i].iov_len);
 203         while (len < a->iov[i].iov_len && *p++ == *q++) {
 204             len++;
 205         }
 206
 207         offset += len;
 208
 209         if (len != a->iov[i].iov_len) {
 210             return offset;
 211         }
 212     }
 213     return -1;
 214 }
 215
 216 typedef struct {
 217     int src_index;
 218     struct iovec *src_iov;
 219     void *dest_base;
 220 } IOVectorSortElem;
 221
 222 static int sortelem_cmp_src_base(const void *a, const void *b)
 223 {
 224     const IOVectorSortElem *elem_a = a;
 225     const IOVectorSortElem *elem_b = b;
 226
 227     /* Don't overflow */
 228     if (elem_a->src_iov->iov_base < elem_b->src_iov->iov_base) {
 229         return -1;
 230     } else if (elem_a->src_iov->iov_base > elem_b->src_iov->iov_base) {
 231         return 1;
 232     } else {
 233         return 0;
 234     }
 235 }
 236
 237 static int sortelem_cmp_src_index(const void *a, const void *b)
 238 {
 239     const IOVectorSortElem *elem_a = a;
 240     const IOVectorSortElem *elem_b = b;
 241
 242     return elem_a->src_index - elem_b->src_index;
 243 }
 244
 245 /**
 246  * Copy contents of I/O vector
 247  *
 248  * The relative relationships of overlapping iovecs are preserved.  This is
 249  * necessary to ensure identical semantics in the cloned I/O vector.
 250  */
 251 static void blkverify_iovec_clone(QEMUIOVector *dest, const QEMUIOVector *src,
 252                                   void *buf)
 253 {
 254     IOVectorSortElem sortelems[src->niov];
 255     void *last_end;
 256     int i;
 257
 258     /* Sort by source iovecs by base address */
 259     for (i = 0; i < src->niov; i++) {
 260         sortelems[i].src_index = i;
 261         sortelems[i].src_iov = &src->iov[i];
 262     }
 263     qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_base);
 264
 265     /* Allocate buffer space taking into account overlapping iovecs */
 266     last_end = NULL;
 267     for (i = 0; i < src->niov; i++) {
 268         struct iovec *cur = sortelems[i].src_iov;
 269         ptrdiff_t rewind = 0;
 270
 271         /* Detect overlap */
 272         if (last_end && last_end > cur->iov_base) {
 273             rewind = last_end - cur->iov_base;
 274         }
 275
 276         sortelems[i].dest_base = buf - rewind;
 277         buf += cur->iov_len - MIN(rewind, cur->iov_len);
 278         last_end = MAX(cur->iov_base + cur->iov_len, last_end);
 279     }
 280
 281     /* Sort by source iovec index and build destination iovec */
 282     qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_index);
 283     for (i = 0; i < src->niov; i++) {
 284         qemu_iovec_add(dest, sortelems[i].dest_base, src->iov[i].iov_len);
 285     }
 286 }
 287
 288 static BlkverifyAIOCB *blkverify_aio_get(BlockDriverState *bs, bool is_write,
 289                                          int64_t sector_num, QEMUIOVector *qiov,
 290                                          int nb_sectors,
 291                                          BlockDriverCompletionFunc *cb,
 292                                          void *opaque)
 293 {
 294     BlkverifyAIOCB *acb = qemu_aio_get(&blkverify_aiocb_info, bs, cb, opaque);
 295
 296     acb->bh = NULL;
 297     acb->is_write = is_write;
 298     acb->sector_num = sector_num;
 299     acb->nb_sectors = nb_sectors;
 300     acb->ret = -EINPROGRESS;
 301     acb->done = 0;
 302     acb->qiov = qiov;
 303     acb->buf = NULL;
 304     acb->verify = NULL;
 305     acb->finished = NULL;
 306     return acb;
 307 }
 308
 309 static void blkverify_aio_bh(void *opaque)
 310 {
 311     BlkverifyAIOCB *acb = opaque;
 312
 313     qemu_bh_delete(acb->bh);
 314     if (acb->buf) {
 315         qemu_iovec_destroy(&acb->raw_qiov);
 316         qemu_vfree(acb->buf);
 317     }
 318     acb->common.cb(acb->common.opaque, acb->ret);
 319     if (acb->finished) {
 320         *acb->finished = true;
 321     }
 322     qemu_aio_release(acb);
 323 }
 324
 325 static void blkverify_aio_cb(void *opaque, int ret)
 326 {
 327     BlkverifyAIOCB *acb = opaque;
 328
 329     switch (++acb->done) {
 330     case 1:
 331         acb->ret = ret;
 332         break;
 333
 334     case 2:
 335         if (acb->ret != ret) {
 336             blkverify_err(acb, "return value mismatch %d != %d", acb->ret, ret);
 337         }
 338
 339         if (acb->verify) {
 340             acb->verify(acb);
 341         }
 342
 343         acb->bh = qemu_bh_new(blkverify_aio_bh, acb);
 344         qemu_bh_schedule(acb->bh);
 345         break;
 346     }
 347 }
 348
 349 static void blkverify_verify_readv(BlkverifyAIOCB *acb)
 350 {
 351     ssize_t offset = blkverify_iovec_compare(acb->qiov, &acb->raw_qiov);
 352     if (offset != -1) {
 353         blkverify_err(acb, "contents mismatch in sector %" PRId64,
 354                       acb->sector_num + (int64_t)(offset / BDRV_SECTOR_SIZE));
 355     }
 356 }
 357
 358 static BlockDriverAIOCB *blkverify_aio_readv(BlockDriverState *bs,
 359         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 360         BlockDriverCompletionFunc *cb, void *opaque)
 361 {
 362     BDRVBlkverifyState *s = bs->opaque;
 363     BlkverifyAIOCB *acb = blkverify_aio_get(bs, false, sector_num, qiov,
 364                                             nb_sectors, cb, opaque);
 365
 366     acb->verify = blkverify_verify_readv;
 367     acb->buf = qemu_blockalign(bs->file, qiov->size);
 368     qemu_iovec_init(&acb->raw_qiov, acb->qiov->niov);
 369     blkverify_iovec_clone(&acb->raw_qiov, qiov, acb->buf);
 370
 371     bdrv_aio_readv(s->test_file, sector_num, qiov, nb_sectors,
 372                    blkverify_aio_cb, acb);
 373     bdrv_aio_readv(bs->file, sector_num, &acb->raw_qiov, nb_sectors,
 374                    blkverify_aio_cb, acb);
 375     return &acb->common;
 376 }
 377
 378 static BlockDriverAIOCB *blkverify_aio_writev(BlockDriverState *bs,
 379         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 380         BlockDriverCompletionFunc *cb, void *opaque)
 381 {
 382     BDRVBlkverifyState *s = bs->opaque;
 383     BlkverifyAIOCB *acb = blkverify_aio_get(bs, true, sector_num, qiov,
 384                                             nb_sectors, cb, opaque);
 385
 386     bdrv_aio_writev(s->test_file, sector_num, qiov, nb_sectors,
 387                     blkverify_aio_cb, acb);
 388     bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors,
 389                     blkverify_aio_cb, acb);
 390     return &acb->common;
 391 }
 392
 393 static BlockDriverAIOCB *blkverify_aio_flush(BlockDriverState *bs,
 394                                              BlockDriverCompletionFunc *cb,
 395                                              void *opaque)
 396 {
 397     BDRVBlkverifyState *s = bs->opaque;
 398
 399     /* Only flush test file, the raw file is not important */
 400     return bdrv_aio_flush(s->test_file, cb, opaque);
 401 }
 402
 403 static BlockDriver bdrv_blkverify = {
 404     .format_name            = "blkverify",
 405     .protocol_name          = "blkverify",
 406     .instance_size          = sizeof(BDRVBlkverifyState),
 407
 408     .bdrv_parse_filename    = blkverify_parse_filename,
 409     .bdrv_file_open         = blkverify_open,
 410     .bdrv_close             = blkverify_close,
 411     .bdrv_getlength         = blkverify_getlength,
 412
 413     .bdrv_aio_readv         = blkverify_aio_readv,
 414     .bdrv_aio_writev        = blkverify_aio_writev,
 415     .bdrv_aio_flush         = blkverify_aio_flush,
 416 };
 417
 418 static void bdrv_blkverify_init(void)
 419 {
 420     bdrv_register(&bdrv_blkverify);
 421 }
 422
 423 block_init(bdrv_blkverify_init);