aio: remove aio_disable_external() API

All callers now pass is_external=false to aio_set_fd_handler() and
aio_set_event_notifier(). The aio_disable_external() API that
temporarily disables fd handle

aio: remove aio_disable_external() API

All callers now pass is_external=false to aio_set_fd_handler() and
aio_set_event_notifier(). The aio_disable_external() API that
temporarily disables fd handlers that were registered is_external=true
is therefore dead code.

Remove aio_disable_external(), aio_enable_external(), and the
is_external arguments to aio_set_fd_handler() and
aio_set_event_notifier().

The entire test-fdmon-epoll test is removed because its sole purpose was
testing aio_disable_external().

Parts of this patch were generated using the following coccinelle
(https://coccinelle.lip6.fr/) semantic patch:

@@
expression ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque;
@@
- aio_set_fd_handler(ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque)
+ aio_set_fd_handler(ctx, fd, io_read, io_write, io_poll, io_poll_ready, opaque)

@@
expression ctx, notifier, is_external, io_read, io_poll, io_poll_ready;
@@
- aio_set_event_notifier(ctx, notifier, is_external, io_read, io_poll, io_poll_ready)
+ aio_set_event_notifier(ctx, notifier, io_read, io_poll, io_poll_ready)

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-21-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

block/block.h
-> block/block-io.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac8.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>

show more ...

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

block/block.h
-> block/block-io.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac8.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>

show more ...

qapi block: Elide redundant has_FOO in generated C

The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with. Recent commit "qapi: Start to
elide re

qapi block: Elide redundant has_FOO in generated C

The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with. Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step. This is the step for qapi/block*.json.

Said commit explains the transformation in more detail.

There is one instance of the invariant violation mentioned there:
qcow2_signal_corruption() passes false, "" when node_name is an empty
string. Take care to pass NULL then.

The previous two commits cleaned up two more.

Additionally, helper bdrv_latency_histogram_stats() loses its output
parameters and returns a value instead.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-11-armbru@redhat.com>
[Fixes for #ifndef LIBRBD_SUPPORTS_ENCRYPTION and MacOS squashed in]

show more ...

ssh: add missing coroutine_fn annotation

ssh_write is only called from ssh_co_writev.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id:

ssh: add missing coroutine_fn annotation

ssh_write is only called from ssh_co_writev.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-5-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: add BDRV_REQ_REGISTERED_BUF request flag

Block drivers may optimize I/O requests accessing buffers previously
registered with bdrv_register_buf(). Checking whether all elements of a
request's

block: add BDRV_REQ_REGISTERED_BUF request flag

Block drivers may optimize I/O requests accessing buffers previously
registered with bdrv_register_buf(). Checking whether all elements of a
request's QEMUIOVector are within previously registered buffers is
expensive, so we need a hint from the user to avoid costly checks.

Add a BDRV_REQ_REGISTERED_BUF request flag to indicate that all
QEMUIOVector elements in an I/O request are known to be within
previously registered buffers.

Always pass the flag through to driver read/write functions. There is
little harm in passing the flag to a driver that does not use it.
Passing the flag to drivers avoids changes across many block drivers.
Filter drivers would need to explicitly support the flag and pass
through to their children when the children support it. That's a lot of
code changes and it's hard to remember to do that everywhere, leading to
silent reduced performance when the flag is accidentally dropped.

The only problematic scenario with the approach in this patch is when a
driver passes the flag through to internal I/O requests that don't use
the same I/O buffer. In that case the hint may be set when it should
actually be clear. This is a rare case though so the risk is low.

Some drivers have assert(!flags), which no longer works when
BDRV_REQ_REGISTERED_BUF is passed in. These assertions aren't very
useful anyway since the functions are called almost exclusively by
bdrv_driver_preadv/pwritev() so if we get flags handling right there
then the assertion is not needed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

ssh: add missing coroutine_fn annotation

ssh_write is only called from ssh_co_writev.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id:

ssh: add missing coroutine_fn annotation

ssh_write is only called from ssh_co_writev.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-5-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: add BDRV_REQ_REGISTERED_BUF request flag

Block drivers may optimize I/O requests accessing buffers previously
registered with bdrv_register_buf(). Checking whether all elements of a
request's

block: add BDRV_REQ_REGISTERED_BUF request flag

Block drivers may optimize I/O requests accessing buffers previously
registered with bdrv_register_buf(). Checking whether all elements of a
request's QEMUIOVector are within previously registered buffers is
expensive, so we need a hint from the user to avoid costly checks.

Add a BDRV_REQ_REGISTERED_BUF request flag to indicate that all
QEMUIOVector elements in an I/O request are known to be within
previously registered buffers.

Always pass the flag through to driver read/write functions. There is
little harm in passing the flag to a driver that does not use it.
Passing the flag to drivers avoids changes across many block drivers.
Filter drivers would need to explicitly support the flag and pass
through to their children when the children support it. That's a lot of
code changes and it's hard to remember to do that everywhere, leading to
silent reduced performance when the flag is accidentally dropped.

The only problematic scenario with the approach in this patch is when a
driver passes the flag through to internal I/O requests that don't use
the same I/O buffer. In that case the hint may be set when it should
actually be clear. This is a rare case though so the risk is low.

Some drivers have assert(!flags), which no longer works when
BDRV_REQ_REGISTERED_BUF is passed in. These assertions aren't very
useful anyway since the functions are called almost exclusively by
bdrv_driver_preadv/pwritev() so if we get flags handling right there
then the assertion is not needed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

Replace GCC_FMT_ATTR with G_GNUC_PRINTF

One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.

Signed-off-by:

Replace GCC_FMT_ATTR with G_GNUC_PRINTF

One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

show more ...

block: print the server key type and fingerprint on failure

When validating the server key fingerprint fails, it is difficult for
the user to know what they got wrong. The fingerprint accepted by QE

block: print the server key type and fingerprint on failure

When validating the server key fingerprint fails, it is difficult for
the user to know what they got wrong. The fingerprint accepted by QEMU
is received in a different format than OpenSSH displays. There can also
be keys for multiple different ciphers in known_hosts. It may not be
obvious which cipher QEMU will use and whether it will be the same
as OpenSSH. Address this by printing the server key type and its
corresponding fingerprint in the format QEMU accepts.

Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

show more ...

block: support sha256 fingerprint with pre-blockdev options

When support for sha256 fingerprint checking was aded in

commit bf783261f0aee6e81af3916bff7606d71ccdc153
Author: Daniel P. Berrangé <

block: support sha256 fingerprint with pre-blockdev options

When support for sha256 fingerprint checking was aded in

commit bf783261f0aee6e81af3916bff7606d71ccdc153
Author: Daniel P. Berrangé <berrange@redhat.com>
Date: Tue Jun 22 12:51:56 2021 +0100

block/ssh: add support for sha256 host key fingerprints

it was only made to work with -blockdev. Getting it working with
-drive requires some extra custom parsing.

Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

show more ...

aio-posix: split poll check from ready handler

Adaptive polling measures the execution time of the polling check plus
handlers called when a polled event becomes ready. Handlers can take a
significa

aio-posix: split poll check from ready handler

Adaptive polling measures the execution time of the polling check plus
handlers called when a polled event becomes ready. Handlers can take a
significant amount of time, making it look like polling was running for
a long time when in fact the event handler was running for a long time.

For example, on Linux the io_submit(2) syscall invoked when a virtio-blk
device's virtqueue becomes ready can take 10s of microseconds. This
can exceed the default polling interval (32 microseconds) and cause
adaptive polling to stop polling.

By excluding the handler's execution time from the polling check we make
the adaptive polling calculation more accurate. As a result, the event
loop now stays in polling mode where previously it would have fallen
back to file descriptor monitoring.

The following data was collected with virtio-blk num-queues=2
event_idx=off using an IOThread. Before:

168k IOPS, IOThread syscalls:

9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0) = 16
9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8) = 8
9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8) = 8
9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3
9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512) = 8
9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512) = 8
9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512) = 8
9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0) = 32

174k IOPS (+3.6%), IOThread syscalls:

9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0) = 32
9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8) = 8
9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8) = 8
9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50) = 32

Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because
the IOThread stays in polling mode instead of falling back to file
descriptor monitoring.

As usual, polling is not implemented on Windows so this patch ignores
the new io_poll_read() callback in aio-win32.c.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-2-stefanha@redhat.com

[Fixed up aio_set_event_notifier() calls in
tests/unit/test-fdmon-epoll.c added after this series was queued.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

util/uri: do not check argument of uri_free()

uri_free() checks if its argument is NULL in uri_clean() and g_free().
There is no need to check the argument before the call.

Signed-off-by: Heinrich

util/uri: do not check argument of uri_free()

uri_free() checks if its argument is NULL in uri_clean() and g_free().
There is no need to check the argument before the call.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Message-Id: <20210629063602.4239-1-xypron.glpk@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block/ssh: add support for sha256 host key fingerprints

Currently the SSH block driver supports MD5 and SHA1 for host key
fingerprints. This is a cryptographically sensitive operation and
so these h

block/ssh: add support for sha256 host key fingerprints

Currently the SSH block driver supports MD5 and SHA1 for host key
fingerprints. This is a cryptographically sensitive operation and
so these hash algorithms are inadequate by modern standards. This
adds support for SHA256 which has been supported in libssh since
the 0.8.1 release.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210622115156.138458-1-berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block/ssh: Bump minimum libssh version to 0.8.7

It has been over two years since RHEL-8 was released, and thus per the
platform build policy, we no longer need to support RHEL-7 as a build
target. S

block/ssh: Bump minimum libssh version to 0.8.7

It has been over two years since RHEL-8 was released, and thus per the
platform build policy, we no longer need to support RHEL-7 as a build
target. So from the RHEL-7 perspective, we do not have to support
libssh v0.7 anymore now.

Let's look at the versions from other distributions and operating
systems - according to repology.org, current shipping versions are:

RHEL-8: 0.9.4
Debian Buster: 0.8.7
openSUSE Leap 15.2: 0.8.7
Ubuntu LTS 18.04: 0.8.0 *
Ubuntu LTS 20.04: 0.9.3
FreeBSD: 0.9.5
Fedora 33: 0.9.5
Fedora 34: 0.9.5
OpenBSD: 0.9.5
macOS HomeBrew: 0.9.5
HaikuPorts: 0.9.5

* The version of libssh in Ubuntu 18.04 claims to be 0.8.0 from the
name of the package, but in reality it is a 0.7 patched up as a
Frankenstein monster with patches from the 0.8 development branch.
This gave us some headaches in the past already and so it never worked
with QEMU. All attempts to get it supported have failed in the past,
patches for QEMU have never been merged and a request to Ubuntu to
fix it in their 18.04 distro has been ignored:

https://bugs.launchpad.net/ubuntu/+source/libssh/+bug/1847514

Thus we really should ignore the libssh in Ubuntu 18.04 in QEMU, too.

Fix it by bumping the minimum libssh version to something that is
greater than 0.8.0 now. Debian Buster and openSUSE Leap have the
oldest version and so 0.8.7 is the new minimum.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20210519155859.344569-1-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

show more ...

qapi: Smooth another visitor error checking pattern

Convert

visit_type_FOO(v, ..., &ptr, &err);
...
if (err) {
...
}

to

visit_type_FOO(v, ..., &ptr, errp);
...

qapi: Smooth another visitor error checking pattern

Convert

visit_type_FOO(v, ..., &ptr, &err);
...
if (err) {
...
}

to

visit_type_FOO(v, ..., &ptr, errp);
...
if (!ptr) {
...
}

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary. Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>

show more ...

error: Eliminate error_propagate() with Coccinelle, part 2

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right

error: Eliminate error_propagate() with Coccinelle, part 2

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away. The previous commit did that with a Coccinelle script I
consider fairly trustworthy. This commit uses the same script with
the matching of return taken out, i.e. we convert

if (!foo(..., &err)) {
...
error_propagate(errp, err);
...
}

to

if (!foo(..., errp)) {
...
...
}

This is unsound: @err could still be read between afterwards. I don't
know how to express "no read of @err without an intervening write" in
Coccinelle. Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually. qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>

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qemu-option: Use returned bool to check for failure

The previous commit enables conversion of

foo(..., &err);
if (err) {
...
}

to

if (!foo(..., &err)) {
...
}

qemu-option: Use returned bool to check for failure

The previous commit enables conversion of

foo(..., &err);
if (err) {
...
}

to

if (!foo(..., &err)) {
...
}

for QemuOpts functions that now return true / false on success /
error. Coccinelle script:

@@
identifier fun = {
opts_do_parse, parse_option_bool, parse_option_number,
parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
qemu_opts_validate
};
expression list args, args2;
typedef Error;
Error *err;
@@
- fun(args, &err, args2);
- if (err)
+ if (!fun(args, &err, args2))
{
...
}

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]

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block: Drop unused .bdrv_has_zero_init_truncate

Now that there are no clients of bdrv_has_zero_init_truncate, none of
the drivers need to worry about providing it.

What's more, this eliminates a so

block: Drop unused .bdrv_has_zero_init_truncate

Now that there are no clients of bdrv_has_zero_init_truncate, none of
the drivers need to worry about providing it.

What's more, this eliminates a source of some confusion: a literal
reading of the documentation as written in ceaca56f and implemented in
commit 1dcaf527 claims that a driver which returns 0 for
bdrv_has_zero_init_truncate() must not return 1 for
bdrv_has_zero_init(); this condition was violated for parallels, qcow,
and sometimes for vdi, although in practice it did not matter since
those drivers also lacked .bdrv_co_truncate.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-10-eblake@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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ssh: Support BDRV_REQ_ZERO_WRITE for truncate

Our .bdrv_has_zero_init_truncate can detect when the remote side
always zero fills; we can reuse that same knowledge to implement
BDRV_REQ_ZERO_WRITE by

ssh: Support BDRV_REQ_ZERO_WRITE for truncate

Our .bdrv_has_zero_init_truncate can detect when the remote side
always zero fills; we can reuse that same knowledge to implement
BDRV_REQ_ZERO_WRITE by ignoring it when the server gives it to us for
free.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-7-eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Add flags to BlockDriver.bdrv_co_truncate()

This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate()
driver callbacks, and a supported_truncate_flags field in
BlockDriverState th

block: Add flags to BlockDriver.bdrv_co_truncate()

This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate()
driver callbacks, and a supported_truncate_flags field in
BlockDriverState that allows drivers to advertise support for request
flags in the context of truncate.

For now, we always pass 0 and no drivers declare support for any flag.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: pass BlockDriver reference to the .bdrv_co_create

This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.

Signed-off-by: Maxi

block: pass BlockDriver reference to the .bdrv_co_create

This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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