qemu/block/blkverify.c
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   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 "qemu/osdep.h"
  11#include "qapi/error.h"
  12#include "qemu/sockets.h" /* for EINPROGRESS on Windows */
  13#include "block/block_int.h"
  14#include "qapi/qmp/qdict.h"
  15#include "qapi/qmp/qstring.h"
  16#include "qemu/cutils.h"
  17#include "qemu/module.h"
  18#include "qemu/option.h"
  19
  20typedef struct {
  21    BdrvChild *test_file;
  22} BDRVBlkverifyState;
  23
  24typedef struct BlkverifyRequest {
  25    Coroutine *co;
  26    BlockDriverState *bs;
  27
  28    /* Request metadata */
  29    bool is_write;
  30    uint64_t offset;
  31    uint64_t bytes;
  32    int flags;
  33
  34    int (*request_fn)(BdrvChild *, int64_t, int64_t, QEMUIOVector *,
  35                      BdrvRequestFlags);
  36
  37    int ret;                    /* test image result */
  38    int raw_ret;                /* raw image result */
  39
  40    unsigned int done;          /* completion counter */
  41
  42    QEMUIOVector *qiov;         /* user I/O vector */
  43    QEMUIOVector *raw_qiov;     /* cloned I/O vector for raw file */
  44} BlkverifyRequest;
  45
  46static void GCC_FMT_ATTR(2, 3) blkverify_err(BlkverifyRequest *r,
  47                                             const char *fmt, ...)
  48{
  49    va_list ap;
  50
  51    va_start(ap, fmt);
  52    fprintf(stderr, "blkverify: %s offset=%" PRId64 " bytes=%" PRId64 " ",
  53            r->is_write ? "write" : "read", r->offset, r->bytes);
  54    vfprintf(stderr, fmt, ap);
  55    fprintf(stderr, "\n");
  56    va_end(ap);
  57    exit(1);
  58}
  59
  60/* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */
  61static void blkverify_parse_filename(const char *filename, QDict *options,
  62                                     Error **errp)
  63{
  64    const char *c;
  65    QString *raw_path;
  66
  67
  68    /* Parse the blkverify: prefix */
  69    if (!strstart(filename, "blkverify:", &filename)) {
  70        /* There was no prefix; therefore, all options have to be already
  71           present in the QDict (except for the filename) */
  72        qdict_put_str(options, "x-image", filename);
  73        return;
  74    }
  75
  76    /* Parse the raw image filename */
  77    c = strchr(filename, ':');
  78    if (c == NULL) {
  79        error_setg(errp, "blkverify requires raw copy and original image path");
  80        return;
  81    }
  82
  83    /* TODO Implement option pass-through and set raw.filename here */
  84    raw_path = qstring_from_substr(filename, 0, c - filename);
  85    qdict_put(options, "x-raw", raw_path);
  86
  87    /* TODO Allow multi-level nesting and set file.filename here */
  88    filename = c + 1;
  89    qdict_put_str(options, "x-image", filename);
  90}
  91
  92static QemuOptsList runtime_opts = {
  93    .name = "blkverify",
  94    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
  95    .desc = {
  96        {
  97            .name = "x-raw",
  98            .type = QEMU_OPT_STRING,
  99            .help = "[internal use only, will be removed]",
 100        },
 101        {
 102            .name = "x-image",
 103            .type = QEMU_OPT_STRING,
 104            .help = "[internal use only, will be removed]",
 105        },
 106        { /* end of list */ }
 107    },
 108};
 109
 110static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
 111                          Error **errp)
 112{
 113    BDRVBlkverifyState *s = bs->opaque;
 114    QemuOpts *opts;
 115    int ret;
 116
 117    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 118    if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 119        ret = -EINVAL;
 120        goto fail;
 121    }
 122
 123    /* Open the raw file */
 124    bs->file = bdrv_open_child(qemu_opt_get(opts, "x-raw"), options, "raw",
 125                               bs, &child_of_bds,
 126                               BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
 127                               false, errp);
 128    if (!bs->file) {
 129        ret = -EINVAL;
 130        goto fail;
 131    }
 132
 133    /* Open the test file */
 134    s->test_file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options,
 135                                   "test", bs, &child_of_bds, BDRV_CHILD_DATA,
 136                                   false, errp);
 137    if (!s->test_file) {
 138        ret = -EINVAL;
 139        goto fail;
 140    }
 141
 142    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
 143    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
 144
 145    ret = 0;
 146fail:
 147    qemu_opts_del(opts);
 148    return ret;
 149}
 150
 151static void blkverify_close(BlockDriverState *bs)
 152{
 153    BDRVBlkverifyState *s = bs->opaque;
 154
 155    bdrv_unref_child(bs, s->test_file);
 156    s->test_file = NULL;
 157}
 158
 159static int64_t blkverify_getlength(BlockDriverState *bs)
 160{
 161    BDRVBlkverifyState *s = bs->opaque;
 162
 163    return bdrv_getlength(s->test_file->bs);
 164}
 165
 166static void coroutine_fn blkverify_do_test_req(void *opaque)
 167{
 168    BlkverifyRequest *r = opaque;
 169    BDRVBlkverifyState *s = r->bs->opaque;
 170
 171    r->ret = r->request_fn(s->test_file, r->offset, r->bytes, r->qiov,
 172                           r->flags);
 173    r->done++;
 174    qemu_coroutine_enter_if_inactive(r->co);
 175}
 176
 177static void coroutine_fn blkverify_do_raw_req(void *opaque)
 178{
 179    BlkverifyRequest *r = opaque;
 180
 181    r->raw_ret = r->request_fn(r->bs->file, r->offset, r->bytes, r->raw_qiov,
 182                               r->flags);
 183    r->done++;
 184    qemu_coroutine_enter_if_inactive(r->co);
 185}
 186
 187static int coroutine_fn
 188blkverify_co_prwv(BlockDriverState *bs, BlkverifyRequest *r, uint64_t offset,
 189                  uint64_t bytes, QEMUIOVector *qiov, QEMUIOVector *raw_qiov,
 190                  int flags, bool is_write)
 191{
 192    Coroutine *co_a, *co_b;
 193
 194    *r = (BlkverifyRequest) {
 195        .co         = qemu_coroutine_self(),
 196        .bs         = bs,
 197        .offset     = offset,
 198        .bytes      = bytes,
 199        .qiov       = qiov,
 200        .raw_qiov   = raw_qiov,
 201        .flags      = flags,
 202        .is_write   = is_write,
 203        .request_fn = is_write ? bdrv_co_pwritev : bdrv_co_preadv,
 204    };
 205
 206    co_a = qemu_coroutine_create(blkverify_do_test_req, r);
 207    co_b = qemu_coroutine_create(blkverify_do_raw_req, r);
 208
 209    qemu_coroutine_enter(co_a);
 210    qemu_coroutine_enter(co_b);
 211
 212    while (r->done < 2) {
 213        qemu_coroutine_yield();
 214    }
 215
 216    if (r->ret != r->raw_ret) {
 217        blkverify_err(r, "return value mismatch %d != %d", r->ret, r->raw_ret);
 218    }
 219
 220    return r->ret;
 221}
 222
 223static int coroutine_fn
 224blkverify_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 225                    QEMUIOVector *qiov, int flags)
 226{
 227    BlkverifyRequest r;
 228    QEMUIOVector raw_qiov;
 229    void *buf;
 230    ssize_t cmp_offset;
 231    int ret;
 232
 233    buf = qemu_blockalign(bs->file->bs, qiov->size);
 234    qemu_iovec_init(&raw_qiov, qiov->niov);
 235    qemu_iovec_clone(&raw_qiov, qiov, buf);
 236
 237    ret = blkverify_co_prwv(bs, &r, offset, bytes, qiov, &raw_qiov, flags,
 238                            false);
 239
 240    cmp_offset = qemu_iovec_compare(qiov, &raw_qiov);
 241    if (cmp_offset != -1) {
 242        blkverify_err(&r, "contents mismatch at offset %" PRId64,
 243                      offset + cmp_offset);
 244    }
 245
 246    qemu_iovec_destroy(&raw_qiov);
 247    qemu_vfree(buf);
 248
 249    return ret;
 250}
 251
 252static int coroutine_fn
 253blkverify_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 254                     QEMUIOVector *qiov, int flags)
 255{
 256    BlkverifyRequest r;
 257    return blkverify_co_prwv(bs, &r, offset, bytes, qiov, qiov, flags, true);
 258}
 259
 260static int blkverify_co_flush(BlockDriverState *bs)
 261{
 262    BDRVBlkverifyState *s = bs->opaque;
 263
 264    /* Only flush test file, the raw file is not important */
 265    return bdrv_co_flush(s->test_file->bs);
 266}
 267
 268static bool blkverify_recurse_can_replace(BlockDriverState *bs,
 269                                          BlockDriverState *to_replace)
 270{
 271    BDRVBlkverifyState *s = bs->opaque;
 272
 273    /*
 274     * blkverify quits the whole qemu process if there is a mismatch
 275     * between bs->file->bs and s->test_file->bs.  Therefore, we know
 276     * know that both must match bs and we can recurse down to either.
 277     */
 278    return bdrv_recurse_can_replace(bs->file->bs, to_replace) ||
 279           bdrv_recurse_can_replace(s->test_file->bs, to_replace);
 280}
 281
 282static void blkverify_refresh_filename(BlockDriverState *bs)
 283{
 284    BDRVBlkverifyState *s = bs->opaque;
 285
 286    if (bs->file->bs->exact_filename[0]
 287        && s->test_file->bs->exact_filename[0])
 288    {
 289        int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 290                           "blkverify:%s:%s",
 291                           bs->file->bs->exact_filename,
 292                           s->test_file->bs->exact_filename);
 293        if (ret >= sizeof(bs->exact_filename)) {
 294            /* An overflow makes the filename unusable, so do not report any */
 295            bs->exact_filename[0] = 0;
 296        }
 297    }
 298}
 299
 300static char *blkverify_dirname(BlockDriverState *bs, Error **errp)
 301{
 302    /* In general, there are two BDSs with different dirnames below this one;
 303     * so there is no unique dirname we could return (unless both are equal by
 304     * chance). Therefore, to be consistent, just always return NULL. */
 305    error_setg(errp, "Cannot generate a base directory for blkverify nodes");
 306    return NULL;
 307}
 308
 309static BlockDriver bdrv_blkverify = {
 310    .format_name                      = "blkverify",
 311    .protocol_name                    = "blkverify",
 312    .instance_size                    = sizeof(BDRVBlkverifyState),
 313
 314    .bdrv_parse_filename              = blkverify_parse_filename,
 315    .bdrv_file_open                   = blkverify_open,
 316    .bdrv_close                       = blkverify_close,
 317    .bdrv_child_perm                  = bdrv_default_perms,
 318    .bdrv_getlength                   = blkverify_getlength,
 319    .bdrv_refresh_filename            = blkverify_refresh_filename,
 320    .bdrv_dirname                     = blkverify_dirname,
 321
 322    .bdrv_co_preadv                   = blkverify_co_preadv,
 323    .bdrv_co_pwritev                  = blkverify_co_pwritev,
 324    .bdrv_co_flush                    = blkverify_co_flush,
 325
 326    .is_filter                        = true,
 327    .bdrv_recurse_can_replace         = blkverify_recurse_can_replace,
 328};
 329
 330static void bdrv_blkverify_init(void)
 331{
 332    bdrv_register(&bdrv_blkverify);
 333}
 334
 335block_init(bdrv_blkverify_init);
 336