xref: /openbmc/qemu/block/blkverify.c (revision 754cb9c0)
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);
338