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mirror: Use BlockBackend for I/O

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This changes the mirror block job to use the job's BlockBackend for
performing its I/O. job->bs isn't used by the mirroring code any more
afterwards.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-04-12 16:17:41 +02:00
parent b880481579
commit e253f4b897
2 changed files with 40 additions and 34 deletions
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70
block/mirror.c
View File

@ -35,7 +35,7 @@ typedef struct MirrorBuffer {
typedef struct MirrorBlockJob {
BlockJob common;
RateLimit limit;
BlockDriverState *target;
BlockBackend *target;
BlockDriverState *base;
/* The name of the graph node to replace */
char *replaces;
@ -156,7 +156,8 @@ static void mirror_read_complete(void *opaque, int ret)
mirror_iteration_done(op, ret);
return;
}
bdrv_aio_writev(s->target, op->sector_num, &op->qiov, op->nb_sectors,
blk_aio_pwritev(s->target, op->sector_num * BDRV_SECTOR_SIZE, &op->qiov,
op->nb_sectors * BDRV_SECTOR_SIZE,
mirror_write_complete, op);
}
@ -185,7 +186,7 @@ static int mirror_cow_align(MirrorBlockJob *s,
need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors,
s->cow_bitmap);
if (need_cow) {
bdrv_round_to_clusters(s->target, *sector_num, *nb_sectors,
bdrv_round_to_clusters(blk_bs(s->target), *sector_num, *nb_sectors,
&align_sector_num, &align_nb_sectors);
}
@ -223,7 +224,7 @@ static inline void mirror_wait_for_io(MirrorBlockJob *s)
static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num,
int nb_sectors)
{
BlockDriverState *source = s->common.bs;
BlockBackend *source = s->common.blk;
int sectors_per_chunk, nb_chunks;
int ret = nb_sectors;
MirrorOp *op;
@ -273,7 +274,8 @@ static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num,
s->sectors_in_flight += nb_sectors;
trace_mirror_one_iteration(s, sector_num, nb_sectors);
bdrv_aio_readv(source, sector_num, &op->qiov, nb_sectors,
blk_aio_preadv(source, sector_num * BDRV_SECTOR_SIZE, &op->qiov,
nb_sectors * BDRV_SECTOR_SIZE,
mirror_read_complete, op);
return ret;
}
@ -295,10 +297,11 @@ static void mirror_do_zero_or_discard(MirrorBlockJob *s,
s->in_flight++;
s->sectors_in_flight += nb_sectors;
if (is_discard) {
bdrv_aio_discard(s->target, sector_num, op->nb_sectors,
mirror_write_complete, op);
blk_aio_discard(s->target, sector_num, op->nb_sectors,
mirror_write_complete, op);
} else {
bdrv_aio_write_zeroes(s->target, sector_num, op->nb_sectors,
blk_aio_pwrite_zeroes(s->target, sector_num * BDRV_SECTOR_SIZE,
op->nb_sectors * BDRV_SECTOR_SIZE,
s->unmap ? BDRV_REQ_MAY_UNMAP : 0,
mirror_write_complete, op);
}
@ -306,7 +309,7 @@ static void mirror_do_zero_or_discard(MirrorBlockJob *s,
static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
{
BlockDriverState *source = s->common.bs;
BlockDriverState *source = blk_bs(s->common.blk);
int64_t sector_num, first_chunk;
uint64_t delay_ns = 0;
/* At least the first dirty chunk is mirrored in one iteration. */
@ -383,7 +386,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
} else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) {
int64_t target_sector_num;
int target_nb_sectors;
bdrv_round_to_clusters(s->target, sector_num, io_sectors,
bdrv_round_to_clusters(blk_bs(s->target), sector_num, io_sectors,
&target_sector_num, &target_nb_sectors);
if (target_sector_num == sector_num &&
target_nb_sectors == io_sectors) {
@ -448,7 +451,8 @@ static void mirror_exit(BlockJob *job, void *opaque)
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
MirrorExitData *data = opaque;
AioContext *replace_aio_context = NULL;
BlockDriverState *src = s->common.bs;
BlockDriverState *src = blk_bs(s->common.blk);
BlockDriverState *target_bs = blk_bs(s->target);
/* Make sure that the source BDS doesn't go away before we called
* block_job_completed(). */
@ -460,20 +464,20 @@ static void mirror_exit(BlockJob *job, void *opaque)
}
if (s->should_complete && data->ret == 0) {
BlockDriverState *to_replace = s->common.bs;
BlockDriverState *to_replace = src;
if (s->to_replace) {
to_replace = s->to_replace;
}
if (bdrv_get_flags(s->target) != bdrv_get_flags(to_replace)) {
bdrv_reopen(s->target, bdrv_get_flags(to_replace), NULL);
if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) {
bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL);
}
/* The mirror job has no requests in flight any more, but we need to
* drain potential other users of the BDS before changing the graph. */
bdrv_drained_begin(s->target);
bdrv_replace_in_backing_chain(to_replace, s->target);
bdrv_drained_end(s->target);
bdrv_drained_begin(target_bs);
bdrv_replace_in_backing_chain(to_replace, target_bs);
bdrv_drained_end(target_bs);
/* We just changed the BDS the job BB refers to */
blk_remove_bs(job->blk);
@ -488,8 +492,8 @@ static void mirror_exit(BlockJob *job, void *opaque)
aio_context_release(replace_aio_context);
}
g_free(s->replaces);
bdrv_op_unblock_all(s->target, s->common.blocker);
bdrv_unref(s->target);
bdrv_op_unblock_all(target_bs, s->common.blocker);
blk_unref(s->target);
block_job_completed(&s->common, data->ret);
g_free(data);
bdrv_drained_end(src);
@ -503,7 +507,8 @@ static void coroutine_fn mirror_run(void *opaque)
{
MirrorBlockJob *s = opaque;
MirrorExitData *data;
BlockDriverState *bs = s->common.bs;
BlockDriverState *bs = blk_bs(s->common.blk);
BlockDriverState *target_bs = blk_bs(s->target);
int64_t sector_num, end, length;
uint64_t last_pause_ns;
BlockDriverInfo bdi;
@ -539,18 +544,18 @@ static void coroutine_fn mirror_run(void *opaque)
* the destination do COW. Instead, we copy sectors around the
* dirty data if needed. We need a bitmap to do that.
*/
bdrv_get_backing_filename(s->target, backing_filename,
bdrv_get_backing_filename(target_bs, backing_filename,
sizeof(backing_filename));
if (!bdrv_get_info(s->target, &bdi) && bdi.cluster_size) {
if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) {
target_cluster_size = bdi.cluster_size;
}
if (backing_filename[0] && !s->target->backing
if (backing_filename[0] && !target_bs->backing
&& s->granularity < target_cluster_size) {
s->buf_size = MAX(s->buf_size, target_cluster_size);
s->cow_bitmap = bitmap_new(length);
}
s->target_cluster_sectors = target_cluster_size >> BDRV_SECTOR_BITS;
s->max_iov = MIN(s->common.bs->bl.max_iov, s->target->bl.max_iov);
s->max_iov = MIN(bs->bl.max_iov, target_bs->bl.max_iov);
end = s->bdev_length / BDRV_SECTOR_SIZE;
s->buf = qemu_try_blockalign(bs, s->buf_size);
@ -565,7 +570,7 @@ static void coroutine_fn mirror_run(void *opaque)
if (!s->is_none_mode) {
/* First part, loop on the sectors and initialize the dirty bitmap. */
BlockDriverState *base = s->base;
bool mark_all_dirty = s->base == NULL && !bdrv_has_zero_init(s->target);
bool mark_all_dirty = s->base == NULL && !bdrv_has_zero_init(target_bs);
for (sector_num = 0; sector_num < end; ) {
/* Just to make sure we are not exceeding int limit. */
@ -635,7 +640,7 @@ static void coroutine_fn mirror_run(void *opaque)
should_complete = false;
if (s->in_flight == 0 && cnt == 0) {
trace_mirror_before_flush(s);
ret = bdrv_flush(s->target);
ret = blk_flush(s->target);
if (ret < 0) {
if (mirror_error_action(s, false, -ret) ==
BLOCK_ERROR_ACTION_REPORT) {
@ -713,7 +718,7 @@ immediate_exit:
data->ret = ret;
/* Before we switch to target in mirror_exit, make sure data doesn't
* change. */
bdrv_drained_begin(s->common.bs);
bdrv_drained_begin(bs);
if (qemu_get_aio_context() == bdrv_get_aio_context(bs)) {
/* FIXME: virtio host notifiers run on iohandler_ctx, therefore the
* above bdrv_drained_end isn't enough to quiesce it. This is ugly, we
@ -740,7 +745,8 @@ static void mirror_complete(BlockJob *job, Error **errp)
Error *local_err = NULL;
int ret;
ret = bdrv_open_backing_file(s->target, NULL, "backing", &local_err);
ret = bdrv_open_backing_file(blk_bs(s->target), NULL, "backing",
&local_err);
if (ret < 0) {
error_propagate(errp, local_err);
return;
@ -823,10 +829,12 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
return;
}
s->target = blk_new();
blk_insert_bs(s->target, target);
s->replaces = g_strdup(replaces);
s->on_source_error = on_source_error;
s->on_target_error = on_target_error;
s->target = target;
s->is_none_mode = is_none_mode;
s->base = base;
s->granularity = granularity;
@ -836,11 +844,12 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
if (!s->dirty_bitmap) {
g_free(s->replaces);
blk_unref(s->target);
block_job_unref(&s->common);
return;
}
bdrv_op_block_all(s->target, s->common.blocker);
bdrv_op_block_all(target, s->common.blocker);
s->common.co = qemu_coroutine_create(mirror_run);
trace_mirror_start(bs, s, s->common.co, opaque);
@ -913,7 +922,6 @@ void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
}
}
bdrv_ref(base);
mirror_start_job(bs, base, NULL, speed, 0, 0,
on_error, on_error, false, cb, opaque, &local_err,
&commit_active_job_driver, false, base);

4
blockdev.c
View File

@ -3621,9 +3621,9 @@ void qmp_drive_mirror(const char *device, const char *target,
has_on_target_error, on_target_error,
has_unmap, unmap,
&local_err);
bdrv_unref(target_bs);
if (local_err) {
error_propagate(errp, local_err);
bdrv_unref(target_bs);
}
out:
aio_context_release(aio_context);
@ -3667,7 +3667,6 @@ void qmp_blockdev_mirror(const char *device, const char *target,
aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
bdrv_ref(target_bs);
bdrv_set_aio_context(target_bs, aio_context);
blockdev_mirror_common(bs, target_bs,
@ -3681,7 +3680,6 @@ void qmp_blockdev_mirror(const char *device, const char *target,
&local_err);
if (local_err) {
error_propagate(errp, local_err);
bdrv_unref(target_bs);
}
aio_context_release(aio_context);