qemu/block
Eric Blake fa778fffdf nbd: Implement NBD_CMD_WRITE_ZEROES on client
Upstream NBD protocol recently added the ability to efficiently
write zeroes without having to send the zeroes over the wire,
along with a flag to control whether the client wants a hole.

The generic block code takes care of falling back to the obvious
write of lots of zeroes if we return -ENOTSUP because the server
does not have WRITE_ZEROES.

Ideally, since NBD_CMD_WRITE_ZEROES does not involve any data
over the wire, we want to support transactions that are much
larger than the normal 32M limit imposed on NBD_CMD_WRITE.  But
the server may still have a limit smaller than UINT_MAX, so
until experimental NBD protocol additions for advertising various
command sizes is finalized (see [1], [2]), for now we just stick to
the same limits as normal writes.

[1] https://github.com/yoe/nbd/blob/extension-info/doc/proto.md
[2] https://sourceforge.net/p/nbd/mailman/message/35081223/

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1476469998-28592-17-git-send-email-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02 09:28:56 +01:00
..
accounting.c block: Clean up includes 2016-01-20 13:36:23 +01:00
archipelago.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
backup.c block: Use block_job_add_bdrv() in backup_start() 2016-10-31 16:52:38 +01:00
blkdebug.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
blkreplay.c replay: allow replay stopping and restarting 2016-09-27 11:57:30 +02:00
blkverify.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
block-backend.c block: introduce BDRV_POLL_WHILE 2016-10-28 21:50:18 +08:00
bochs.c block: Convert bdrv_co_preadv/pwritev to BdrvChild 2016-07-05 16:46:27 +02:00
cloop.c block: Convert bdrv_pread(v) to BdrvChild 2016-07-05 16:46:27 +02:00
commit.c block: Block all nodes involved in the block-commit operation 2016-10-31 16:52:38 +01:00
crypto.c crypto: make PBKDF iterations configurable for LUKS format 2016-09-19 16:30:45 +01:00
curl.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
dirty-bitmap.c block: More operations for meta dirty bitmap 2016-10-24 17:56:07 +02:00
dmg-bz2.c dmg: Move libbz2 code to dmg-bz2.so 2016-10-07 14:14:06 +02:00
dmg.c dmg: Move libbz2 code to dmg-bz2.so 2016-10-07 14:14:06 +02:00
dmg.h dmg: Move libbz2 code to dmg-bz2.so 2016-10-07 14:14:06 +02:00
gluster.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
io.c block: Add bdrv_drain_all_{begin,end}() 2016-10-31 16:51:14 +01:00
iscsi.c block/iscsi: Adding new iSER transport layer option 2016-10-24 11:30:55 +02:00
linux-aio.c linux-aio: fix re-entrant completion processing 2016-09-28 17:11:23 +01:00
Makefile.objs dmg: Move libbz2 code to dmg-bz2.so 2016-10-07 14:14:06 +02:00
mirror.c block: Block all intermediate nodes in commit_active_start() 2016-10-31 16:52:38 +01:00
nbd-client.c nbd: Implement NBD_CMD_WRITE_ZEROES on client 2016-11-02 09:28:56 +01:00
nbd-client.h nbd: Implement NBD_CMD_WRITE_ZEROES on client 2016-11-02 09:28:56 +01:00
nbd.c nbd: Implement NBD_CMD_WRITE_ZEROES on client 2016-11-02 09:28:56 +01:00
nfs.c block/nfs: Introduce runtime_opts in NFS 2016-10-31 16:52:39 +01:00
null.c block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
parallels.c block/parallels: check new image size 2016-08-05 09:59:06 +01:00
qapi.c qapi: rename QmpOutputVisitor to QObjectOutputVisitor 2016-10-25 16:25:54 +02:00
qcow2-cache.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
qcow2-cluster.c qcow2: Support BDRV_REQ_MAY_UNMAP 2016-10-24 17:54:03 +02:00
qcow2-refcount.c block: Convert bdrv_discard() to byte-based 2016-07-20 14:11:55 +01:00
qcow2-snapshot.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
qcow2.c qcow2: Support BDRV_REQ_MAY_UNMAP 2016-10-24 17:54:03 +02:00
qcow2.h qcow2: Support BDRV_REQ_MAY_UNMAP 2016-10-24 17:54:03 +02:00
qcow.c crypto: extend mode as a parameter in qcrypto_cipher_supports() 2016-10-19 10:09:24 +01:00
qed-check.c qed: Use DIV_ROUND_UP 2016-06-07 18:19:24 +03:00
qed-cluster.c block: Clean up includes 2016-01-20 13:36:23 +01:00
qed-gencb.c block: Clean up includes 2016-01-20 13:36:23 +01:00
qed-l2-cache.c block: Clean up includes 2016-01-20 13:36:23 +01:00
qed-table.c block: introduce BDRV_POLL_WHILE 2016-10-28 21:50:18 +08:00
qed.c qed: Implement .bdrv_drain 2016-10-28 21:50:18 +08:00
qed.h block: use aio_bh_schedule_oneshot 2016-10-07 13:34:07 +02:00
quorum.c quorum: do not allocate multiple iovecs for FIFO strategy 2016-10-24 17:56:06 +02:00
raw_bsd.c raw_bsd: add offset and size options 2016-10-31 16:52:39 +01:00
raw-posix.c raw-posix: Don't use bdrv_ioctl() 2016-10-27 19:05:23 +02:00
raw-win32.c block: improve error handling in raw_open 2016-10-24 17:54:03 +02:00
rbd.c rbd: shift byte count as a 64-bit value 2016-10-23 16:10:59 +02:00
replication.c block: prepare bdrv_reopen_multiple to release AioContext 2016-10-28 21:50:18 +08:00
sheepdog.c block: only call aio_poll on the current thread's AioContext 2016-10-28 21:50:18 +08:00
snapshot.c error: Remove NULL checks on error_propagate() calls 2016-06-20 16:38:13 +02:00
ssh.c block/ssh: Use InetSocketAddress options 2016-10-31 16:49:13 +01:00
stream.c block: Support streaming to an intermediate layer 2016-10-31 16:52:38 +01:00
throttle-groups.c throttle: Correct access to wrong BlockBackendPublic structures 2016-10-24 17:54:03 +02:00
trace-events block: Remove bdrv_aio_pdiscard() 2016-10-27 19:05:22 +02:00
vdi.c vdi: Use QEMU UUID API 2016-09-23 11:42:52 +08:00
vhdx-endian.c vhdx: Use QEMU UUID API 2016-09-23 11:42:52 +08:00
vhdx-log.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
vhdx.c vhdx: Use QEMU UUID API 2016-09-23 11:42:52 +08:00
vhdx.h block: vhdx - update PAYLOAD_BLOCK_UNMAPPED value to match 1.00 spec 2014-12-12 15:42:22 +00:00
vmdk.c vmdk: add vmdk_co_pwritev_compressed 2016-09-05 19:06:48 +02:00
vpc.c vpc: Use QEMU UUID API 2016-09-23 11:42:52 +08:00
vvfat.c block: Add "read-only" to the options QDict 2016-09-23 13:36:10 +02:00
win32-aio.c linux-aio: share one LinuxAioState within an AioContext 2016-07-18 15:09:31 +01:00
write-threshold.c block: use bdrv_add_before_write_notifier 2016-10-07 13:34:07 +02:00