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