aboutsummaryrefslogtreecommitdiff
path: root/block/blkverify.c
blob: ba6b1853ae382aaa2aef996e6aff8f0f05932210 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
/*
 * Block protocol for block driver correctness testing
 *
 * Copyright (C) 2010 IBM, Corp.
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/sockets.h" /* for EINPROGRESS on Windows */
#include "block/block_int.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "qemu/cutils.h"
#include "qemu/module.h"
#include "qemu/option.h"

typedef struct {
    BdrvChild *test_file;
} BDRVBlkverifyState;

typedef struct BlkverifyRequest {
    Coroutine *co;
    BlockDriverState *bs;

    /* Request metadata */
    bool is_write;
    uint64_t offset;
    uint64_t bytes;
    int flags;

    int (*request_fn)(BdrvChild *, int64_t, unsigned int, QEMUIOVector *,
                      BdrvRequestFlags);

    int ret;                    /* test image result */
    int raw_ret;                /* raw image result */

    unsigned int done;          /* completion counter */

    QEMUIOVector *qiov;         /* user I/O vector */
    QEMUIOVector *raw_qiov;     /* cloned I/O vector for raw file */
} BlkverifyRequest;

static void GCC_FMT_ATTR(2, 3) blkverify_err(BlkverifyRequest *r,
                                             const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    fprintf(stderr, "blkverify: %s offset=%" PRId64 " bytes=%" PRId64 " ",
            r->is_write ? "write" : "read", r->offset, r->bytes);
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
    va_end(ap);
    exit(1);
}

/* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */
static void blkverify_parse_filename(const char *filename, QDict *options,
                                     Error **errp)
{
    const char *c;
    QString *raw_path;


    /* Parse the blkverify: prefix */
    if (!strstart(filename, "blkverify:", &filename)) {
        /* There was no prefix; therefore, all options have to be already
           present in the QDict (except for the filename) */
        qdict_put_str(options, "x-image", filename);
        return;
    }

    /* Parse the raw image filename */
    c = strchr(filename, ':');
    if (c == NULL) {
        error_setg(errp, "blkverify requires raw copy and original image path");
        return;
    }

    /* TODO Implement option pass-through and set raw.filename here */
    raw_path = qstring_from_substr(filename, 0, c - filename);
    qdict_put(options, "x-raw", raw_path);

    /* TODO Allow multi-level nesting and set file.filename here */
    filename = c + 1;
    qdict_put_str(options, "x-image", filename);
}

static QemuOptsList runtime_opts = {
    .name = "blkverify",
    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
    .desc = {
        {
            .name = "x-raw",
            .type = QEMU_OPT_STRING,
            .help = "[internal use only, will be removed]",
        },
        {
            .name = "x-image",
            .type = QEMU_OPT_STRING,
            .help = "[internal use only, will be removed]",
        },
        { /* end of list */ }
    },
};

static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
                          Error **errp)
{
    BDRVBlkverifyState *s = bs->opaque;
    QemuOpts *opts;
    Error *local_err = NULL;
    int ret;

    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
    qemu_opts_absorb_qdict(opts, options, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        ret = -EINVAL;
        goto fail;
    }

    /* Open the raw file */
    bs->file = bdrv_open_child(qemu_opt_get(opts, "x-raw"), options, "raw",
                               bs, &child_file, false, &local_err);
    if (local_err) {
        ret = -EINVAL;
        error_propagate(errp, local_err);
        goto fail;
    }

    /* Open the test file */
    s->test_file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options,
                                   "test", bs, &child_format, false,
                                   &local_err);
    if (local_err) {
        ret = -EINVAL;
        error_propagate(errp, local_err);
        goto fail;
    }

    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;

    ret = 0;
fail:
    qemu_opts_del(opts);
    return ret;
}

static void blkverify_close(BlockDriverState *bs)
{
    BDRVBlkverifyState *s = bs->opaque;

    bdrv_unref_child(bs, s->test_file);
    s->test_file = NULL;
}

static int64_t blkverify_getlength(BlockDriverState *bs)
{
    BDRVBlkverifyState *s = bs->opaque;

    return bdrv_getlength(s->test_file->bs);
}

static void coroutine_fn blkverify_do_test_req(void *opaque)
{
    BlkverifyRequest *r = opaque;
    BDRVBlkverifyState *s = r->bs->opaque;

    r->ret = r->request_fn(s->test_file, r->offset, r->bytes, r->qiov,
                           r->flags);
    r->done++;
    qemu_coroutine_enter_if_inactive(r->co);
}

static void coroutine_fn blkverify_do_raw_req(void *opaque)
{
    BlkverifyRequest *r = opaque;

    r->raw_ret = r->request_fn(r->bs->file, r->offset, r->bytes, r->raw_qiov,
                               r->flags);
    r->done++;
    qemu_coroutine_enter_if_inactive(r->co);
}

static int coroutine_fn
blkverify_co_prwv(BlockDriverState *bs, BlkverifyRequest *r, uint64_t offset,
                  uint64_t bytes, QEMUIOVector *qiov, QEMUIOVector *raw_qiov,
                  int flags, bool is_write)
{
    Coroutine *co_a, *co_b;

    *r = (BlkverifyRequest) {
        .co         = qemu_coroutine_self(),
        .bs         = bs,
        .offset     = offset,
        .bytes      = bytes,
        .qiov       = qiov,
        .raw_qiov   = raw_qiov,
        .flags      = flags,
        .is_write   = is_write,
        .request_fn = is_write ? bdrv_co_pwritev : bdrv_co_preadv,
    };

    co_a = qemu_coroutine_create(blkverify_do_test_req, r);
    co_b = qemu_coroutine_create(blkverify_do_raw_req, r);

    qemu_coroutine_enter(co_a);
    qemu_coroutine_enter(co_b);

    while (r->done < 2) {
        qemu_coroutine_yield();
    }

    if (r->ret != r->raw_ret) {
        blkverify_err(r, "return value mismatch %d != %d", r->ret, r->raw_ret);
    }

    return r->ret;
}

static int coroutine_fn
blkverify_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                    QEMUIOVector *qiov, int flags)
{
    BlkverifyRequest r;
    QEMUIOVector raw_qiov;
    void *buf;
    ssize_t cmp_offset;
    int ret;

    buf = qemu_blockalign(bs->file->bs, qiov->size);
    qemu_iovec_init(&raw_qiov, qiov->niov);
    qemu_iovec_clone(&raw_qiov, qiov, buf);

    ret = blkverify_co_prwv(bs, &r, offset, bytes, qiov, &raw_qiov, flags,
                            false);

    cmp_offset = qemu_iovec_compare(qiov, &raw_qiov);
    if (cmp_offset != -1) {
        blkverify_err(&r, "contents mismatch at offset %" PRId64,
                      offset + cmp_offset);
    }

    qemu_iovec_destroy(&raw_qiov);
    qemu_vfree(buf);

    return ret;
}

static int coroutine_fn
blkverify_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                     QEMUIOVector *qiov, int flags)
{
    BlkverifyRequest r;
    return blkverify_co_prwv(bs, &r, offset, bytes, qiov, qiov, flags, true);
}

static int blkverify_co_flush(BlockDriverState *bs)
{
    BDRVBlkverifyState *s = bs->opaque;

    /* Only flush test file, the raw file is not important */
    return bdrv_co_flush(s->test_file->bs);
}

static bool blkverify_recurse_can_replace(BlockDriverState *bs,
                                          BlockDriverState *to_replace)
{
    BDRVBlkverifyState *s = bs->opaque;

    /*
     * blkverify quits the whole qemu process if there is a mismatch
     * between bs->file->bs and s->test_file->bs.  Therefore, we know
     * know that both must match bs and we can recurse down to either.
     */
    return bdrv_recurse_can_replace(bs->file->bs, to_replace) ||
           bdrv_recurse_can_replace(s->test_file->bs, to_replace);
}

static void blkverify_refresh_filename(BlockDriverState *bs)
{
    BDRVBlkverifyState *s = bs->opaque;

    if (bs->file->bs->exact_filename[0]
        && s->test_file->bs->exact_filename[0])
    {
        int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
                           "blkverify:%s:%s",
                           bs->file->bs->exact_filename,
                           s->test_file->bs->exact_filename);
        if (ret >= sizeof(bs->exact_filename)) {
            /* An overflow makes the filename unusable, so do not report any */
            bs->exact_filename[0] = 0;
        }
    }
}

static char *blkverify_dirname(BlockDriverState *bs, Error **errp)
{
    /* In general, there are two BDSs with different dirnames below this one;
     * so there is no unique dirname we could return (unless both are equal by
     * chance). Therefore, to be consistent, just always return NULL. */
    error_setg(errp, "Cannot generate a base directory for blkverify nodes");
    return NULL;
}

static BlockDriver bdrv_blkverify = {
    .format_name                      = "blkverify",
    .protocol_name                    = "blkverify",
    .instance_size                    = sizeof(BDRVBlkverifyState),

    .bdrv_parse_filename              = blkverify_parse_filename,
    .bdrv_file_open                   = blkverify_open,
    .bdrv_close                       = blkverify_close,
    .bdrv_child_perm                  = bdrv_filter_default_perms,
    .bdrv_getlength                   = blkverify_getlength,
    .bdrv_refresh_filename            = blkverify_refresh_filename,
    .bdrv_dirname                     = blkverify_dirname,

    .bdrv_co_preadv                   = blkverify_co_preadv,
    .bdrv_co_pwritev                  = blkverify_co_pwritev,
    .bdrv_co_flush                    = blkverify_co_flush,

    .is_filter                        = true,
    .bdrv_recurse_can_replace         = blkverify_recurse_can_replace,
};

static void bdrv_blkverify_init(void)
{
    bdrv_register(&bdrv_blkverify);
}

block_init(bdrv_blkverify_init);