xemu/include/block
Max Reitz ceaca56fee block: Add bdrv_has_zero_init_truncate()
No .bdrv_has_zero_init() implementation returns 1 if growing the file
would add non-zero areas (at least with PREALLOC_MODE_OFF), so using it
in lieu of this new function was always safe.

But on the other hand, it is possible that growing an image that is not
zero-initialized would still add a zero-initialized area, like when
using nonpreallocating truncation on a preallocated image.  For callers
that care only about truncation, not about creation with potential
preallocation, this new function is useful.

Alternatively, we could have added a PreallocMode parameter to
bdrv_has_zero_init().  But the only user would have been qemu-img
convert, which does not have a plain PreallocMode value right now -- it
would have to parse the creation option to obtain it.  Therefore, the
simpler solution is to let bdrv_has_zero_init() inquire the
preallocation status and add the new bdrv_has_zero_init_truncate() that
presupposes PREALLOC_MODE_OFF.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-4-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19 17:13:26 +02:00
..
accounting.h block/accounting: introduce latency histogram 2018-03-19 14:58:37 -05:00
aio-wait.h Clean up decorations and whitespace around header guards 2019-05-13 08:58:55 +02:00
aio.h Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
block_backup.h block/backup: drop unused synchronization interface 2018-12-14 11:52:40 +01:00
block_int.h block: Add bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
block.h block: Add bdrv_has_zero_init_truncate() 2019-08-19 17:13:26 +02:00
blockjob_int.h block: Really pause block jobs on drain 2018-06-18 15:03:25 +02:00
blockjob.h blockdev: blockdev_mark_auto_del: drop usage of bs->job 2019-06-18 16:41:10 +02:00
dirty-bitmap.h qapi: implement block-dirty-bitmap-remove transaction action 2019-08-16 16:28:03 -04:00
nbd.h block/nbd: use non-blocking io channel for nbd negotiation 2019-08-15 13:22:14 -05:00
nvme.h nvme: add Get/Set Feature Timestamp support 2019-06-04 15:22:09 +02:00
qapi.h block/qapi: Clean up how we print to monitor or stdout 2019-04-18 22:18:59 +02:00
qdict.h block: Factor out qobject_input_visitor_new_flat_confused() 2018-06-15 14:49:44 +02:00
raw-aio.h include: Make headers more self-contained 2019-08-16 13:31:51 +02:00
snapshot.h block/snapshot: remove bdrv_snapshot_delete_by_id_or_name 2019-02-25 15:03:18 +01:00
thread-pool.h Clean up decorations and whitespace around header guards 2016-07-12 16:20:46 +02:00
throttle-groups.h throttle-groups: fix restart coroutine iothread race 2019-01-24 10:02:28 +00:00
write-threshold.h include: Make headers more self-contained 2019-08-16 13:31:51 +02:00