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