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, 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
  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     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;
 146 fail:
 147     qemu_opts_del(opts);
 148     return ret;
 149 }
 150
 151 static 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
 159 static int64_t blkverify_getlength(BlockDriverState *bs)
 160 {
 161     BDRVBlkverifyState *s = bs->opaque;
 162
 163     return bdrv_getlength(s->test_file->bs);
 164 }
 165
 166 static 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
 177 static 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
 187 static int coroutine_fn
 188 blkverify_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
 223 static int coroutine_fn
 224 blkverify_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
 252 static int coroutine_fn
 253 blkverify_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
 260 static 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
 268 static 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
 282 static 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
 300 static 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
 309 static 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
 330 static void bdrv_blkverify_init(void)
 331 {
 332     bdrv_register(&bdrv_blkverify);
 333 }
 334
 335 block_init(bdrv_blkverify_init);