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 "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
  20 typedef struct {
  21     BdrvChild *test_file;
  22 } BDRVBlkverifyState;
  23
  24 typedef 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, unsigned int, 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
  46 static 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 */
  61 static 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
  92 static 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
 110 static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
 111                           Error **errp)
 112 {
 113     BDRVBlkverifyState *s = bs->opaque;
 114     QemuOpts *opts;
 115     Error *local_err = NULL;
 116     int ret;
 117
 118     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 119     qemu_opts_absorb_qdict(opts, options, &local_err);
 120     if (local_err) {
 121         error_propagate(errp, local_err);
 122         ret = -EINVAL;
 123         goto fail;
 124     }
 125
 126     /* Open the raw file */
 127     bs->file = bdrv_open_child(qemu_opt_get(opts, "x-raw"), options, "raw",
 128                                bs, &child_of_bds,
 129                                BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
 130                                false, &local_err);
 131     if (local_err) {
 132         ret = -EINVAL;
 133         error_propagate(errp, local_err);
 134         goto fail;
 135     }
 136
 137     /* Open the test file */
 138     s->test_file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options,
 139                                    "test", bs, &child_of_bds, BDRV_CHILD_DATA,
 140                                    false, &local_err);
 141     if (local_err) {
 142         ret = -EINVAL;
 143         error_propagate(errp, local_err);
 144         goto fail;
 145     }
 146
 147     bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
 148     bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
 149
 150     ret = 0;
 151 fail:
 152     qemu_opts_del(opts);
 153     return ret;
 154 }
 155
 156 static void blkverify_close(BlockDriverState *bs)
 157 {
 158     BDRVBlkverifyState *s = bs->opaque;
 159
 160     bdrv_unref_child(bs, s->test_file);
 161     s->test_file = NULL;
 162 }
 163
 164 static int64_t blkverify_getlength(BlockDriverState *bs)
 165 {
 166     BDRVBlkverifyState *s = bs->opaque;
 167
 168     return bdrv_getlength(s->test_file->bs);
 169 }
 170
 171 static void coroutine_fn blkverify_do_test_req(void *opaque)
 172 {
 173     BlkverifyRequest *r = opaque;
 174     BDRVBlkverifyState *s = r->bs->opaque;
 175
 176     r->ret = r->request_fn(s->test_file, r->offset, r->bytes, r->qiov,
 177                            r->flags);
 178     r->done++;
 179     qemu_coroutine_enter_if_inactive(r->co);
 180 }
 181
 182 static void coroutine_fn blkverify_do_raw_req(void *opaque)
 183 {
 184     BlkverifyRequest *r = opaque;
 185
 186     r->raw_ret = r->request_fn(r->bs->file, r->offset, r->bytes, r->raw_qiov,
 187                                r->flags);
 188     r->done++;
 189     qemu_coroutine_enter_if_inactive(r->co);
 190 }
 191
 192 static int coroutine_fn
 193 blkverify_co_prwv(BlockDriverState *bs, BlkverifyRequest *r, uint64_t offset,
 194                   uint64_t bytes, QEMUIOVector *qiov, QEMUIOVector *raw_qiov,
 195                   int flags, bool is_write)
 196 {
 197     Coroutine *co_a, *co_b;
 198
 199     *r = (BlkverifyRequest) {
 200         .co         = qemu_coroutine_self(),
 201         .bs         = bs,
 202         .offset     = offset,
 203         .bytes      = bytes,
 204         .qiov       = qiov,
 205         .raw_qiov   = raw_qiov,
 206         .flags      = flags,
 207         .is_write   = is_write,
 208         .request_fn = is_write ? bdrv_co_pwritev : bdrv_co_preadv,
 209     };
 210
 211     co_a = qemu_coroutine_create(blkverify_do_test_req, r);
 212     co_b = qemu_coroutine_create(blkverify_do_raw_req, r);
 213
 214     qemu_coroutine_enter(co_a);
 215     qemu_coroutine_enter(co_b);
 216
 217     while (r->done < 2) {
 218         qemu_coroutine_yield();
 219     }
 220
 221     if (r->ret != r->raw_ret) {
 222         blkverify_err(r, "return value mismatch %d != %d", r->ret, r->raw_ret);
 223     }
 224
 225     return r->ret;
 226 }
 227
 228 static int coroutine_fn
 229 blkverify_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 230                     QEMUIOVector *qiov, int flags)
 231 {
 232     BlkverifyRequest r;
 233     QEMUIOVector raw_qiov;
 234     void *buf;
 235     ssize_t cmp_offset;
 236     int ret;
 237
 238     buf = qemu_blockalign(bs->file->bs, qiov->size);
 239     qemu_iovec_init(&raw_qiov, qiov->niov);
 240     qemu_iovec_clone(&raw_qiov, qiov, buf);
 241
 242     ret = blkverify_co_prwv(bs, &r, offset, bytes, qiov, &raw_qiov, flags,
 243                             false);
 244
 245     cmp_offset = qemu_iovec_compare(qiov, &raw_qiov);
 246     if (cmp_offset != -1) {
 247         blkverify_err(&r, "contents mismatch at offset %" PRId64,
 248                       offset + cmp_offset);
 249     }
 250
 251     qemu_iovec_destroy(&raw_qiov);
 252     qemu_vfree(buf);
 253
 254     return ret;
 255 }
 256
 257 static int coroutine_fn
 258 blkverify_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 259                      QEMUIOVector *qiov, int flags)
 260 {
 261     BlkverifyRequest r;
 262     return blkverify_co_prwv(bs, &r, offset, bytes, qiov, qiov, flags, true);
 263 }
 264
 265 static int blkverify_co_flush(BlockDriverState *bs)
 266 {
 267     BDRVBlkverifyState *s = bs->opaque;
 268
 269     /* Only flush test file, the raw file is not important */
 270     return bdrv_co_flush(s->test_file->bs);
 271 }
 272
 273 static bool blkverify_recurse_can_replace(BlockDriverState *bs,
 274                                           BlockDriverState *to_replace)
 275 {
 276     BDRVBlkverifyState *s = bs->opaque;
 277
 278     /*
 279      * blkverify quits the whole qemu process if there is a mismatch
 280      * between bs->file->bs and s->test_file->bs.  Therefore, we know
 281      * know that both must match bs and we can recurse down to either.
 282      */
 283     return bdrv_recurse_can_replace(bs->file->bs, to_replace) ||
 284            bdrv_recurse_can_replace(s->test_file->bs, to_replace);
 285 }
 286
 287 static void blkverify_refresh_filename(BlockDriverState *bs)
 288 {
 289     BDRVBlkverifyState *s = bs->opaque;
 290
 291     if (bs->file->bs->exact_filename[0]
 292         && s->test_file->bs->exact_filename[0])
 293     {
 294         int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 295                            "blkverify:%s:%s",
 296                            bs->file->bs->exact_filename,
 297                            s->test_file->bs->exact_filename);
 298         if (ret >= sizeof(bs->exact_filename)) {
 299             /* An overflow makes the filename unusable, so do not report any */
 300             bs->exact_filename[0] = 0;
 301         }
 302     }
 303 }
 304
 305 static char *blkverify_dirname(BlockDriverState *bs, Error **errp)
 306 {
 307     /* In general, there are two BDSs with different dirnames below this one;
 308      * so there is no unique dirname we could return (unless both are equal by
 309      * chance). Therefore, to be consistent, just always return NULL. */
 310     error_setg(errp, "Cannot generate a base directory for blkverify nodes");
 311     return NULL;
 312 }
 313
 314 static BlockDriver bdrv_blkverify = {
 315     .format_name                      = "blkverify",
 316     .protocol_name                    = "blkverify",
 317     .instance_size                    = sizeof(BDRVBlkverifyState),
 318
 319     .bdrv_parse_filename              = blkverify_parse_filename,
 320     .bdrv_file_open                   = blkverify_open,
 321     .bdrv_close                       = blkverify_close,
 322     .bdrv_child_perm                  = bdrv_default_perms,
 323     .bdrv_getlength                   = blkverify_getlength,
 324     .bdrv_refresh_filename            = blkverify_refresh_filename,
 325     .bdrv_dirname                     = blkverify_dirname,
 326
 327     .bdrv_co_preadv                   = blkverify_co_preadv,
 328     .bdrv_co_pwritev                  = blkverify_co_pwritev,
 329     .bdrv_co_flush                    = blkverify_co_flush,
 330
 331     .is_filter                        = true,
 332     .bdrv_recurse_can_replace         = blkverify_recurse_can_replace,
 333 };
 334
 335 static void bdrv_blkverify_init(void)
 336 {
 337     bdrv_register(&bdrv_blkverify);
 338 }
 339
 340 block_init(bdrv_blkverify_init);