xref: /openbmc/qemu/block/blkverify.c (revision 3665dd6bb9043bef181c91e2dce9e1efff47ed51)
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-io.h"
14  #include "block/block_int.h"
15  #include "qapi/qmp/qdict.h"
16  #include "qapi/qmp/qstring.h"
17  #include "qemu/cutils.h"
18  #include "qemu/module.h"
19  #include "qemu/option.h"
20  #include "qemu/memalign.h"
21  
22  typedef struct {
23      BdrvChild *test_file;
24  } BDRVBlkverifyState;
25  
26  typedef struct BlkverifyRequest {
27      Coroutine *co;
28      BlockDriverState *bs;
29  
30      /* Request metadata */
31      bool is_write;
32      uint64_t offset;
33      uint64_t bytes;
34      int flags;
35  
36      int GRAPH_RDLOCK_PTR (*request_fn)(
37          BdrvChild *, int64_t, int64_t, QEMUIOVector *, BdrvRequestFlags);
38  
39      int ret;                    /* test image result */
40      int raw_ret;                /* raw image result */
41  
42      unsigned int done;          /* completion counter */
43  
44      QEMUIOVector *qiov;         /* user I/O vector */
45      QEMUIOVector *raw_qiov;     /* cloned I/O vector for raw file */
46  } BlkverifyRequest;
47  
blkverify_err(BlkverifyRequest * r,const char * fmt,...)48  static void G_GNUC_PRINTF(2, 3) blkverify_err(BlkverifyRequest *r,
49                                               const char *fmt, ...)
50  {
51      va_list ap;
52  
53      va_start(ap, fmt);
54      fprintf(stderr, "blkverify: %s offset=%" PRId64 " bytes=%" PRId64 " ",
55              r->is_write ? "write" : "read", r->offset, r->bytes);
56      vfprintf(stderr, fmt, ap);
57      fprintf(stderr, "\n");
58      va_end(ap);
59      exit(1);
60  }
61  
62  /* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */
blkverify_parse_filename(const char * filename,QDict * options,Error ** errp)63  static void blkverify_parse_filename(const char *filename, QDict *options,
64                                       Error **errp)
65  {
66      const char *c;
67      QString *raw_path;
68  
69  
70      /* Parse the blkverify: prefix */
71      if (!strstart(filename, "blkverify:", &filename)) {
72          /* There was no prefix; therefore, all options have to be already
73             present in the QDict (except for the filename) */
74          qdict_put_str(options, "x-image", filename);
75          return;
76      }
77  
78      /* Parse the raw image filename */
79      c = strchr(filename, ':');
80      if (c == NULL) {
81          error_setg(errp, "blkverify requires raw copy and original image path");
82          return;
83      }
84  
85      /* TODO Implement option pass-through and set raw.filename here */
86      raw_path = qstring_from_substr(filename, 0, c - filename);
87      qdict_put(options, "x-raw", raw_path);
88  
89      /* TODO Allow multi-level nesting and set file.filename here */
90      filename = c + 1;
91      qdict_put_str(options, "x-image", filename);
92  }
93  
94  static QemuOptsList runtime_opts = {
95      .name = "blkverify",
96      .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
97      .desc = {
98          {
99              .name = "x-raw",
100              .type = QEMU_OPT_STRING,
101              .help = "[internal use only, will be removed]",
102          },
103          {
104              .name = "x-image",
105              .type = QEMU_OPT_STRING,
106              .help = "[internal use only, will be removed]",
107          },
108          { /* end of list */ }
109      },
110  };
111  
blkverify_open(BlockDriverState * bs,QDict * options,int flags,Error ** errp)112  static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
113                            Error **errp)
114  {
115      BDRVBlkverifyState *s = bs->opaque;
116      QemuOpts *opts;
117      int ret;
118  
119      opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
120      if (!qemu_opts_absorb_qdict(opts, options, errp)) {
121          ret = -EINVAL;
122          goto fail;
123      }
124  
125      /* Open the raw file */
126      ret = bdrv_open_file_child(qemu_opt_get(opts, "x-raw"), options, "raw",
127                                 bs, errp);
128      if (ret < 0) {
129          goto fail;
130      }
131  
132      /* Open the test file */
133      s->test_file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options,
134                                     "test", bs, &child_of_bds, BDRV_CHILD_DATA,
135                                     false, errp);
136      if (!s->test_file) {
137          ret = -EINVAL;
138          goto fail;
139      }
140  
141      bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
142      bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
143  
144      ret = 0;
145  fail:
146      qemu_opts_del(opts);
147      return ret;
148  }
149  
blkverify_close(BlockDriverState * bs)150  static void blkverify_close(BlockDriverState *bs)
151  {
152      BDRVBlkverifyState *s = bs->opaque;
153  
154      bdrv_graph_wrlock();
155      bdrv_unref_child(bs, s->test_file);
156      s->test_file = NULL;
157      bdrv_graph_wrunlock();
158  }
159  
160  static int64_t coroutine_fn GRAPH_RDLOCK
blkverify_co_getlength(BlockDriverState * bs)161  blkverify_co_getlength(BlockDriverState *bs)
162  {
163      BDRVBlkverifyState *s = bs->opaque;
164  
165      return bdrv_co_getlength(s->test_file->bs);
166  }
167  
blkverify_do_test_req(void * opaque)168  static void coroutine_fn blkverify_do_test_req(void *opaque)
169  {
170      BlkverifyRequest *r = opaque;
171      BDRVBlkverifyState *s = r->bs->opaque;
172  
173      bdrv_graph_co_rdlock();
174      r->ret = r->request_fn(s->test_file, r->offset, r->bytes, r->qiov,
175                             r->flags);
176      bdrv_graph_co_rdunlock();
177  
178      r->done++;
179      qemu_coroutine_enter_if_inactive(r->co);
180  }
181  
blkverify_do_raw_req(void * opaque)182  static void coroutine_fn blkverify_do_raw_req(void *opaque)
183  {
184      BlkverifyRequest *r = opaque;
185  
186      bdrv_graph_co_rdlock();
187      r->raw_ret = r->request_fn(r->bs->file, r->offset, r->bytes, r->raw_qiov,
188                                 r->flags);
189      bdrv_graph_co_rdunlock();
190  
191      r->done++;
192      qemu_coroutine_enter_if_inactive(r->co);
193  }
194  
195  static int coroutine_fn GRAPH_RDLOCK
blkverify_co_prwv(BlockDriverState * bs,BlkverifyRequest * r,uint64_t offset,uint64_t bytes,QEMUIOVector * qiov,QEMUIOVector * raw_qiov,int flags,bool is_write)196  blkverify_co_prwv(BlockDriverState *bs, BlkverifyRequest *r, uint64_t offset,
197                    uint64_t bytes, QEMUIOVector *qiov, QEMUIOVector *raw_qiov,
198                    int flags, bool is_write)
199  {
200      Coroutine *co_a, *co_b;
201  
202      *r = (BlkverifyRequest) {
203          .co         = qemu_coroutine_self(),
204          .bs         = bs,
205          .offset     = offset,
206          .bytes      = bytes,
207          .qiov       = qiov,
208          .raw_qiov   = raw_qiov,
209          .flags      = flags,
210          .is_write   = is_write,
211          .request_fn = is_write ? bdrv_co_pwritev : bdrv_co_preadv,
212      };
213  
214      co_a = qemu_coroutine_create(blkverify_do_test_req, r);
215      co_b = qemu_coroutine_create(blkverify_do_raw_req, r);
216  
217      qemu_coroutine_enter(co_a);
218      qemu_coroutine_enter(co_b);
219  
220      while (r->done < 2) {
221          qemu_coroutine_yield();
222      }
223  
224      if (r->ret != r->raw_ret) {
225          blkverify_err(r, "return value mismatch %d != %d", r->ret, r->raw_ret);
226      }
227  
228      return r->ret;
229  }
230  
231  static int coroutine_fn GRAPH_RDLOCK
blkverify_co_preadv(BlockDriverState * bs,int64_t offset,int64_t bytes,QEMUIOVector * qiov,BdrvRequestFlags flags)232  blkverify_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
233                      QEMUIOVector *qiov, BdrvRequestFlags flags)
234  {
235      BlkverifyRequest r;
236      QEMUIOVector raw_qiov;
237      void *buf;
238      ssize_t cmp_offset;
239      int ret;
240  
241      buf = qemu_blockalign(bs->file->bs, qiov->size);
242      qemu_iovec_init(&raw_qiov, qiov->niov);
243      qemu_iovec_clone(&raw_qiov, qiov, buf);
244  
245      ret = blkverify_co_prwv(bs, &r, offset, bytes, qiov, &raw_qiov,
246                              flags & ~BDRV_REQ_REGISTERED_BUF, false);
247  
248      cmp_offset = qemu_iovec_compare(qiov, &raw_qiov);
249      if (cmp_offset != -1) {
250          blkverify_err(&r, "contents mismatch at offset %" PRId64,
251                        offset + cmp_offset);
252      }
253  
254      qemu_iovec_destroy(&raw_qiov);
255      qemu_vfree(buf);
256  
257      return ret;
258  }
259  
260  static int coroutine_fn GRAPH_RDLOCK
blkverify_co_pwritev(BlockDriverState * bs,int64_t offset,int64_t bytes,QEMUIOVector * qiov,BdrvRequestFlags flags)261  blkverify_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
262                       QEMUIOVector *qiov, BdrvRequestFlags flags)
263  {
264      BlkverifyRequest r;
265      return blkverify_co_prwv(bs, &r, offset, bytes, qiov, qiov, flags, true);
266  }
267  
blkverify_co_flush(BlockDriverState * bs)268  static int coroutine_fn GRAPH_RDLOCK blkverify_co_flush(BlockDriverState *bs)
269  {
270      BDRVBlkverifyState *s = bs->opaque;
271  
272      /* Only flush test file, the raw file is not important */
273      return bdrv_co_flush(s->test_file->bs);
274  }
275  
276  static bool GRAPH_RDLOCK
blkverify_recurse_can_replace(BlockDriverState * bs,BlockDriverState * to_replace)277  blkverify_recurse_can_replace(BlockDriverState *bs,
278                                BlockDriverState *to_replace)
279  {
280      BDRVBlkverifyState *s = bs->opaque;
281  
282      /*
283       * blkverify quits the whole qemu process if there is a mismatch
284       * between bs->file->bs and s->test_file->bs.  Therefore, we know
285       * know that both must match bs and we can recurse down to either.
286       */
287      return bdrv_recurse_can_replace(bs->file->bs, to_replace) ||
288             bdrv_recurse_can_replace(s->test_file->bs, to_replace);
289  }
290  
blkverify_refresh_filename(BlockDriverState * bs)291  static void GRAPH_RDLOCK blkverify_refresh_filename(BlockDriverState *bs)
292  {
293      BDRVBlkverifyState *s = bs->opaque;
294  
295      if (bs->file->bs->exact_filename[0]
296          && s->test_file->bs->exact_filename[0])
297      {
298          int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
299                             "blkverify:%s:%s",
300                             bs->file->bs->exact_filename,
301                             s->test_file->bs->exact_filename);
302          if (ret >= sizeof(bs->exact_filename)) {
303              /* An overflow makes the filename unusable, so do not report any */
304              bs->exact_filename[0] = 0;
305          }
306      }
307  }
308  
blkverify_dirname(BlockDriverState * bs,Error ** errp)309  static char *blkverify_dirname(BlockDriverState *bs, Error **errp)
310  {
311      /* In general, there are two BDSs with different dirnames below this one;
312       * so there is no unique dirname we could return (unless both are equal by
313       * chance). Therefore, to be consistent, just always return NULL. */
314      error_setg(errp, "Cannot generate a base directory for blkverify nodes");
315      return NULL;
316  }
317  
318  static BlockDriver bdrv_blkverify = {
319      .format_name                      = "blkverify",
320      .protocol_name                    = "blkverify",
321      .instance_size                    = sizeof(BDRVBlkverifyState),
322  
323      .bdrv_parse_filename              = blkverify_parse_filename,
324      .bdrv_open                        = blkverify_open,
325      .bdrv_close                       = blkverify_close,
326      .bdrv_child_perm                  = bdrv_default_perms,
327      .bdrv_co_getlength                = blkverify_co_getlength,
328      .bdrv_refresh_filename            = blkverify_refresh_filename,
329      .bdrv_dirname                     = blkverify_dirname,
330  
331      .bdrv_co_preadv                   = blkverify_co_preadv,
332      .bdrv_co_pwritev                  = blkverify_co_pwritev,
333      .bdrv_co_flush                    = blkverify_co_flush,
334  
335      .is_filter                        = true,
336      .bdrv_recurse_can_replace         = blkverify_recurse_can_replace,
337  };
338  
bdrv_blkverify_init(void)339  static void bdrv_blkverify_init(void)
340  {
341      bdrv_register(&bdrv_blkverify);
342  }
343  
344  block_init(bdrv_blkverify_init);
345