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