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