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| author | Max Reitz | 2019-07-24 19:12:30 +0200 |
|---|---|---|
| committer | Max Reitz | 2019-08-19 17:13:26 +0200 |
| commit | cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8 (patch) | |
| tree | 2e8dc4f2b68d10a6439335c1f733e563aaf71ec6 /block | |
| parent | qemu-img: Fix bdrv_has_zero_init() use in convert (diff) | |
| download | qemu-cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8.tar.gz qemu-cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8.tar.xz qemu-cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8.zip | |
mirror: Fix bdrv_has_zero_init() use
bdrv_has_zero_init() only has meaning for newly created images or image
areas. If the mirror job itself did not create the image, it cannot
rely on bdrv_has_zero_init()'s result to carry any meaning.
This is the case for drive-mirror with mode=existing and always for
blockdev-mirror.
Note that we only have to zero-initialize the target with sync=full,
because other modes actually do not promise that the target will contain
the same data as the source after the job -- sync=top only promises to
copy anything allocated in the top layer, and sync=none will only copy
new I/O. (Which is how mirror has always handled it.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-3-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/mirror.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/block/mirror.c b/block/mirror.c index 2b870683f1..853e2c7510 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -51,6 +51,8 @@ typedef struct MirrorBlockJob { Error *replace_blocker; bool is_none_mode; BlockMirrorBackingMode backing_mode; + /* Whether the target image requires explicit zero-initialization */ + bool zero_target; MirrorCopyMode copy_mode; BlockdevOnError on_source_error, on_target_error; bool synced; @@ -767,7 +769,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) int ret; int64_t count; - if (base == NULL && !bdrv_has_zero_init(target_bs)) { + if (s->zero_target) { if (!bdrv_can_write_zeroes_with_unmap(target_bs)) { bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length); return 0; @@ -1515,6 +1517,7 @@ static BlockJob *mirror_start_job( const char *replaces, int64_t speed, uint32_t granularity, int64_t buf_size, BlockMirrorBackingMode backing_mode, + bool zero_target, BlockdevOnError on_source_error, BlockdevOnError on_target_error, bool unmap, @@ -1643,6 +1646,7 @@ static BlockJob *mirror_start_job( s->on_target_error = on_target_error; s->is_none_mode = is_none_mode; s->backing_mode = backing_mode; + s->zero_target = zero_target; s->copy_mode = copy_mode; s->base = base; s->granularity = granularity; @@ -1747,6 +1751,7 @@ void mirror_start(const char *job_id, BlockDriverState *bs, int creation_flags, int64_t speed, uint32_t granularity, int64_t buf_size, MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, + bool zero_target, BlockdevOnError on_source_error, BlockdevOnError on_target_error, bool unmap, const char *filter_node_name, @@ -1764,7 +1769,7 @@ void mirror_start(const char *job_id, BlockDriverState *bs, is_none_mode = mode == MIRROR_SYNC_MODE_NONE; base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; mirror_start_job(job_id, bs, creation_flags, target, replaces, - speed, granularity, buf_size, backing_mode, + speed, granularity, buf_size, backing_mode, zero_target, on_source_error, on_target_error, unmap, NULL, NULL, &mirror_job_driver, is_none_mode, base, false, filter_node_name, true, copy_mode, errp); @@ -1791,7 +1796,7 @@ BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs, ret = mirror_start_job( job_id, bs, creation_flags, base, NULL, speed, 0, 0, - MIRROR_LEAVE_BACKING_CHAIN, + MIRROR_LEAVE_BACKING_CHAIN, false, on_error, on_error, true, cb, opaque, &commit_active_job_driver, false, base, auto_complete, filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND, |