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