write-threshold: deal with includes

"qemu/typedefs.h" is enough for include/block/write-threshold.h header
with forward declaration of BlockDriverState. Also drop extra includes
from block/write-thr

write-threshold: deal with includes

"qemu/typedefs.h" is enough for include/block/write-threshold.h header
with forward declaration of BlockDriverState. Also drop extra includes
from block/write-threshold.c and tests/unit/test-write-threshold.c

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210506090621.11848-9-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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test-write-threshold: drop extra TestStruct structure

We don't need this extra logic: it doesn't make code simpler.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-b

test-write-threshold: drop extra TestStruct structure

We don't need this extra logic: it doesn't make code simpler.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-8-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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test-write-threshold: drop extra tests

Testing set/get of one 64bit variable doesn't seem necessary. We have a
lot of such variables. Also remaining tests do test set/get anyway.

Signed-off-by: Vla

test-write-threshold: drop extra tests

Testing set/get of one 64bit variable doesn't seem necessary. We have a
lot of such variables. Also remaining tests do test set/get anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-7-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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block/write-threshold: drop extra APIs

bdrv_write_threshold_exceeded() is unused.

bdrv_write_threshold_is_set() is used only to double check the value of
bs->write_threshold_offset in tests. No rea

block/write-threshold: drop extra APIs

bdrv_write_threshold_exceeded() is unused.

bdrv_write_threshold_is_set() is used only to double check the value of
bs->write_threshold_offset in tests. No real sense in it (both tests do
check real value with help of bdrv_write_threshold_get())

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[mreitz: Adjusted commit message as per Eric's suggestion]
Signed-off-by: Max Reitz <mreitz@redhat.com>

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test-write-threshold: rewrite test_threshold_(not_)trigger tests

These tests use bdrv_write_threshold_exceeded() API, which is used only
for test (since pre-previous commit). Better is testing real

test-write-threshold: rewrite test_threshold_(not_)trigger tests

These tests use bdrv_write_threshold_exceeded() API, which is used only
for test (since pre-previous commit). Better is testing real API, which
is used in block.c as well.

So, let's call bdrv_write_threshold_check_write(), and check is
bs->write_threshold_offset cleared or not (it's cleared iff threshold
triggered).

Also we get rid of BdrvTrackedRequest use here. Note, that paranoiac
bdrv_check_request() calls were added in 8b1170012b1 to protect
BdrvTrackedRequest. Drop them now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-4-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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tests: Move unit tests into a separate directory

The main tests directory still looks very crowded, and it's not
clear which files are part of a unit tests and which belong to
a different test subsy

tests: Move unit tests into a separate directory

The main tests directory still looks very crowded, and it's not
clear which files are part of a unit tests and which belong to
a different test subsystem. Let's clean up the mess and move the
unit tests to a separate directory.

Message-Id: <20210310063314.1049838-1-thuth@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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block: refactor bdrv_check_request: add errp

It's better to pass &error_abort than just assert that result is 0: on
crash, we'll immediately see the reason in the backtrace.

Signed-off-by: Vladimir

block: refactor bdrv_check_request: add errp

It's better to pass &error_abort than just assert that result is 0: on
crash, we'll immediately see the reason in the backtrace.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: fix iotest 206 fallout]
Signed-off-by: Eric Blake <eblake@redhat.com>

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block: introduce BDRV_MAX_LENGTH

We are going to modify block layer to work with 64bit requests. And
first step is moving to int64_t type for both offset and bytes
arguments in all block request rel

block: introduce BDRV_MAX_LENGTH

We are going to modify block layer to work with 64bit requests. And
first step is moving to int64_t type for both offset and bytes
arguments in all block request related functions.

It's mostly safe (when widening signed or unsigned int to int64_t), but
switching from uint64_t is questionable.

So, let's first establish the set of requests we want to work with.
First signed int64_t should be enough, as off_t is signed anyway. Then,
obviously offset + bytes should not overflow.

And most interesting: (offset + bytes) being aligned up should not
overflow as well. Aligned to what alignment? First thing that comes in
mind is bs->bl.request_alignment, as we align up request to this
alignment. But there is another thing: look at
bdrv_mark_request_serialising(). It aligns request up to some given
alignment. And this parameter may be bdrv_get_cluster_size(), which is
often a lot greater than bs->bl.request_alignment.
Note also, that bdrv_mark_request_serialising() uses signed int64_t for
calculations. So, actually, we already depend on some restrictions.

Happily, bdrv_get_cluster_size() returns int and
bs->bl.request_alignment has 32bit unsigned type, but defined to be a
power of 2 less than INT_MAX. So, we may establish, that INT_MAX is
absolute maximum for any kind of alignment that may occur with the
request.

Note, that bdrv_get_cluster_size() is not documented to return power
of 2, still bdrv_mark_request_serialising() behaves like it is.
Also, backup uses bdi.cluster_size and is not prepared to it not being
power of 2.
So, let's establish that Qemu supports only power-of-2 clusters and
alignments.

So, alignment can't be greater than 2^30.

Finally to be safe with calculations, to not calculate different
maximums for different nodes (depending on cluster size and
request_alignment), let's simply set QEMU_ALIGN_DOWN(INT64_MAX, 2^30)
as absolute maximum bytes length for Qemu. Actually, it's not much less
than INT64_MAX.

OK, then, let's apply it to block/io.

Let's consider all block/io entry points of offset/bytes:

4 bytes/offset interface functions: bdrv_co_preadv_part(),
bdrv_co_pwritev_part(), bdrv_co_copy_range_internal() and
bdrv_co_pdiscard() and we check them all with bdrv_check_request().

We also have one entry point with only offset: bdrv_co_truncate().
Check the offset.

And one public structure: BdrvTrackedRequest. Happily, it has only
three external users:

file-posix.c: adopted by this patch
write-threshold.c: only read fields
test-write-threshold.c: sets obviously small constant values

Better is to make the structure private and add corresponding
interfaces.. Still it's not obvious what kind of interface is needed
for file-posix.c. Let's keep it public but add corresponding
assertions.

After this patch we'll convert functions in block/io.c to int64_t bytes
and offset parameters. We can assume that offset/bytes pair always
satisfy new restrictions, and make
corresponding assertions where needed. If we reach some offset/bytes
point in block/io.c missing bdrv_check_request() it is considered a
bug. As well, if block/io.c modifies a offset/bytes request, expanding
it more then aligning up to request_alignment, it's a bug too.

For all io requests except for discard we keep for now old restriction
of 32bit request length.

iotest 206 output error message changed, as now test disk size is
larger than new limit. Add one more test case with new maximum disk
size to cover too-big-L1 case.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201203222713.13507-5-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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tests: Remove unnecessary glib.h includes

Remove glib.h includes, as it is provided by osdep.h.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@lin

tests: Remove unnecessary glib.h includes

Remove glib.h includes, as it is provided by osdep.h.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

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tests: Clean up includes

Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off

tests: Clean up includes

Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>

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block: add event when disk usage exceeds threshold

Managing applications, like oVirt (http://www.ovirt.org), make extensive
use of thin-provisioned disk images.
To let the guest run smoothly and be

block: add event when disk usage exceeds threshold

Managing applications, like oVirt (http://www.ovirt.org), make extensive
use of thin-provisioned disk images.
To let the guest run smoothly and be not unnecessarily paused, oVirt sets
a disk usage threshold (so called 'high water mark') based on the occupation
of the device, and automatically extends the image once the threshold
is reached or exceeded.

In order to detect the crossing of the threshold, oVirt has no choice but
aggressively polling the QEMU monitor using the query-blockstats command.
This lead to unnecessary system load, and is made even worse under scale:
deployments with hundreds of VMs are no longer rare.

To fix this, this patch adds:
* A new monitor command `block-set-write-threshold', to set a mark for
a given block device.
* A new event `BLOCK_WRITE_THRESHOLD', to report if a block device
usage exceeds the threshold.
* A new `write_threshold' field into the `BlockDeviceInfo' structure,
to report the configured threshold.

This will allow the managing application to use smarter and more
efficient monitoring, greatly reducing the need of polling.

[Updated qemu-iotests 067 output to add the new 'write_threshold'
property. --Stefan]
[Changed g_assert_false() to !g_assert() to fix the build on older glib
versions. --Kevin]

Signed-off-by: Francesco Romani <fromani@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1421068273-692-1-git-send-email-fromani@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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