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