BlockDriverState *commit_top_bs;
BlockBackend *top;
BlockBackend *base;
+ BlockDriverState *base_bs;
BlockdevOnError on_error;
- int base_flags;
+ bool base_read_only;
+ bool chain_frozen;
char *backing_file_str;
} CommitBlockJob;
void *buf)
{
int ret = 0;
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = buf,
- .iov_len = bytes,
- };
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
assert(bytes < SIZE_MAX);
- qemu_iovec_init_external(&qiov, &iov, 1);
ret = blk_co_preadv(bs, offset, qiov.size, &qiov, 0);
if (ret < 0) {
return 0;
}
-static void commit_exit(Job *job)
+static int commit_prepare(Job *job)
{
CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);
- BlockJob *bjob = &s->common;
- BlockDriverState *top = blk_bs(s->top);
- BlockDriverState *base = blk_bs(s->base);
- BlockDriverState *commit_top_bs = s->commit_top_bs;
- bool remove_commit_top_bs = false;
- /* Make sure commit_top_bs and top stay around until bdrv_replace_node() */
- bdrv_ref(top);
- bdrv_ref(commit_top_bs);
+ bdrv_unfreeze_backing_chain(s->commit_top_bs, s->base_bs);
+ s->chain_frozen = false;
/* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before
* the normal backing chain can be restored. */
blk_unref(s->base);
+ s->base = NULL;
+
+ /* FIXME: bdrv_drop_intermediate treats total failures and partial failures
+ * identically. Further work is needed to disambiguate these cases. */
+ return bdrv_drop_intermediate(s->commit_top_bs, s->base_bs,
+ s->backing_file_str);
+}
+
+static void commit_abort(Job *job)
+{
+ CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);
+ BlockDriverState *top_bs = blk_bs(s->top);
- if (!job_is_cancelled(job) && job->ret == 0) {
- /* success */
- job->ret = bdrv_drop_intermediate(s->commit_top_bs, base,
- s->backing_file_str);
- } else {
- /* XXX Can (or should) we somehow keep 'consistent read' blocked even
- * after the failed/cancelled commit job is gone? If we already wrote
- * something to base, the intermediate images aren't valid any more. */
- remove_commit_top_bs = true;
+ if (s->chain_frozen) {
+ bdrv_unfreeze_backing_chain(s->commit_top_bs, s->base_bs);
}
+ /* Make sure commit_top_bs and top stay around until bdrv_replace_node() */
+ bdrv_ref(top_bs);
+ bdrv_ref(s->commit_top_bs);
+
+ if (s->base) {
+ blk_unref(s->base);
+ }
+
+ /* free the blockers on the intermediate nodes so that bdrv_replace_nodes
+ * can succeed */
+ block_job_remove_all_bdrv(&s->common);
+
+ /* If bdrv_drop_intermediate() failed (or was not invoked), remove the
+ * commit filter driver from the backing chain now. Do this as the final
+ * step so that the 'consistent read' permission can be granted.
+ *
+ * XXX Can (or should) we somehow keep 'consistent read' blocked even
+ * after the failed/cancelled commit job is gone? If we already wrote
+ * something to base, the intermediate images aren't valid any more. */
+ bdrv_child_try_set_perm(s->commit_top_bs->backing, 0, BLK_PERM_ALL,
+ &error_abort);
+ bdrv_replace_node(s->commit_top_bs, backing_bs(s->commit_top_bs),
+ &error_abort);
+
+ bdrv_unref(s->commit_top_bs);
+ bdrv_unref(top_bs);
+}
+
+static void commit_clean(Job *job)
+{
+ CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);
+
/* restore base open flags here if appropriate (e.g., change the base back
* to r/o). These reopens do not need to be atomic, since we won't abort
* even on failure here */
- if (s->base_flags != bdrv_get_flags(base)) {
- bdrv_reopen(base, s->base_flags, NULL);
+ if (s->base_read_only) {
+ bdrv_reopen_set_read_only(s->base_bs, true, NULL);
}
+
g_free(s->backing_file_str);
blk_unref(s->top);
-
- /* If there is more than one reference to the job (e.g. if called from
- * job_finish_sync()), job_completed() won't free it and therefore the
- * blockers on the intermediate nodes remain. This would cause
- * bdrv_set_backing_hd() to fail. */
- block_job_remove_all_bdrv(bjob);
-
- /* If bdrv_drop_intermediate() didn't already do that, remove the commit
- * filter driver from the backing chain. Do this as the final step so that
- * the 'consistent read' permission can be granted. */
- if (remove_commit_top_bs) {
- bdrv_child_try_set_perm(commit_top_bs->backing, 0, BLK_PERM_ALL,
- &error_abort);
- bdrv_replace_node(commit_top_bs, backing_bs(commit_top_bs),
- &error_abort);
- }
-
- bdrv_unref(commit_top_bs);
- bdrv_unref(top);
}
static int coroutine_fn commit_run(Job *job, Error **errp)
.user_resume = block_job_user_resume,
.drain = block_job_drain,
.run = commit_run,
- .exit = commit_exit,
+ .prepare = commit_prepare,
+ .abort = commit_abort,
+ .clean = commit_clean
},
};
return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
}
-static void bdrv_commit_top_refresh_filename(BlockDriverState *bs, QDict *opts)
+static void bdrv_commit_top_refresh_filename(BlockDriverState *bs)
{
- bdrv_refresh_filename(bs->backing->bs);
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
bs->backing->bs->filename);
}
};
void commit_start(const char *job_id, BlockDriverState *bs,
- BlockDriverState *base, BlockDriverState *top, int64_t speed,
+ BlockDriverState *base, BlockDriverState *top,
+ int creation_flags, int64_t speed,
BlockdevOnError on_error, const char *backing_file_str,
const char *filter_node_name, Error **errp)
{
CommitBlockJob *s;
- int orig_base_flags;
BlockDriverState *iter;
BlockDriverState *commit_top_bs = NULL;
Error *local_err = NULL;
}
s = block_job_create(job_id, &commit_job_driver, NULL, bs, 0, BLK_PERM_ALL,
- speed, JOB_DEFAULT, NULL, NULL, errp);
+ speed, creation_flags, NULL, NULL, errp);
if (!s) {
return;
}
/* convert base to r/w, if necessary */
- orig_base_flags = bdrv_get_flags(base);
- if (!(orig_base_flags & BDRV_O_RDWR)) {
- bdrv_reopen(base, orig_base_flags | BDRV_O_RDWR, &local_err);
- if (local_err != NULL) {
- error_propagate(errp, local_err);
+ s->base_read_only = bdrv_is_read_only(base);
+ if (s->base_read_only) {
+ if (bdrv_reopen_set_read_only(base, false, errp) != 0) {
goto fail;
}
}
}
}
+ if (bdrv_freeze_backing_chain(commit_top_bs, base, errp) < 0) {
+ goto fail;
+ }
+ s->chain_frozen = true;
+
ret = block_job_add_bdrv(&s->common, "base", base, 0, BLK_PERM_ALL, errp);
if (ret < 0) {
goto fail;
if (ret < 0) {
goto fail;
}
+ s->base_bs = base;
/* Required permissions are already taken with block_job_add_bdrv() */
s->top = blk_new(0, BLK_PERM_ALL);
goto fail;
}
- s->base_flags = orig_base_flags;
s->backing_file_str = g_strdup(backing_file_str);
s->on_error = on_error;
return;
fail:
+ if (s->chain_frozen) {
+ bdrv_unfreeze_backing_chain(commit_top_bs, base);
+ }
if (s->base) {
blk_unref(s->base);
}
if (s->top) {
blk_unref(s->top);
}
+ job_early_fail(&s->common.job);
+ /* commit_top_bs has to be replaced after deleting the block job,
+ * otherwise this would fail because of lack of permissions. */
if (commit_top_bs) {
bdrv_replace_node(commit_top_bs, top, &error_abort);
}
- job_early_fail(&s->common.job);
}
BlockDriverState *commit_top_bs = NULL;
BlockDriver *drv = bs->drv;
int64_t offset, length, backing_length;
- int ro, open_flags;
+ int ro;
int64_t n;
int ret = 0;
uint8_t *buf = NULL;
}
ro = bs->backing->bs->read_only;
- open_flags = bs->backing->bs->open_flags;
if (ro) {
- if (bdrv_reopen(bs->backing->bs, open_flags | BDRV_O_RDWR, NULL)) {
+ if (bdrv_reopen_set_read_only(bs->backing->bs, false, NULL)) {
return -EACCES;
}
}
if (ro) {
/* ignoring error return here */
- bdrv_reopen(bs->backing->bs, open_flags & ~BDRV_O_RDWR, NULL);
+ bdrv_reopen_set_read_only(bs->backing->bs, true, NULL);
}
return ret;
projects / mirror_qemu.git / blobdiff