This patch adds an option the specify the offset of the first request
made by qemu-img bench. This allows to benchmark misaligned requests.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

This extends qemu-img bench with an option that makes it use sequential
writes instead of reads for the test run.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

This adds a qemu-img command that allows doing some simple benchmarks
for the block layer without involving guest devices and a real VM.

For the start, this implements only a test of sequential reads.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

Drivers that implement .bdrv_co_pwritev() get the flags passed as an
argument to said function, but we also unconditionally emulate the flags
anyway. We shouldn't do that.

Fix this by clearing all flags that the driver supports natively after
it returns from .bdrv_co_pwritev().

Fixes: 4df863f3 ('block: Make supported_write_flags a per-bds property')
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Returns negative error codes and accompanying error messages in cases where
the device has no tray or the tray is locked and isn't forced open. This
extra information should result in better flexibility in functions that
call do_open_tray.

Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: NColin Lord <clord@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The code to exit the loop after bdrv_snapshot_delete_by_id_or_name()
returned failure was duplicated. The first copy of it was too early so
that the AioContext lock would not be freed. This patch removes it so
that only the second, correct copy remains.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

The problem with excessive flushing was found by a couple of performance
tests:
  - parallel directory tree creation (from 2 processes)
  - 32 cached writes + fsync at the end in a loop

For the first one results improved from 2.6 loops/sec to 3.5 loops/sec.
Each loop creates 10^3 directories with 10 files in each.

For the second one results improved from ~600 fsync/sec to ~1100
fsync/sec. Though, it was run on SSD so it probably won't show such
performance gain on rotational media.

qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
cache entries of a particular cache. This can lead to as many as
2 additional fdatasyncs inside bdrv_flush.

We can simply skip all fdatasync calls inside qcow2_co_flush_to_os
as bdrv_flush for sure will do the job. These flushes are necessary to
keep the right order of writes to the different caches. Though this is
not necessary in the current code base as this ordering is ensured through
the flush in qcow2_cache_flush_dependency().
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Pavel Borzenkov <pborzenkov@virtuozzo.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This is sometimes a useful value we should count in.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

at least bdrv_co_preadv/pwritev expect this.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This creates a new BlockBackend for copying data from an images to the
migration stream on the source host. All I/O for block migration goes
through BlockBackend now.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

This converts the loading part of block migration to use BlockBackend
interfaces rather than accessing the BlockDriverState directly.

Note that this takes a lazy shortcut. We should really use a separate
BlockBackend that is configured for the migration rather than for the
guest (e.g. writethrough caching is unnecessary) and holds its own
reference to the BlockDriverState, but the impact isn't that big and we
didn't have a separate migration reference before either, so it must be
good enough, I guess...
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

Now that all drivers have been converted to a byte interface,
we no longer need a sector interface.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: NEric Blake <eblake@redhat.com>
[ kwolf: Fixed up trace_paio_submit_co() call for qiov == NULL ]
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.

Kill an abuse of the comma operator while at it (fortunately,
the semantics were still right).  Also, the test for requests
not aligned to clusters should be applied always, not just
when a backing file is present.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step on our continuing quest to switch to byte-based
interfaces.

As this is the first byte-based iscsi interface, convert
is_request_lun_aligned() into two versions, one for sectors
and one for bytes.  Also, change from outright -EINVAL failure
on an unaligned request, to instead failing with -ENOTSUP to
trigger a read-modify-write fallback, particularly since the
block layer should be honoring bs->request_alignment to avoid
-EINVAL on read/write requests.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Rename to bdrv_pwrite_zeroes() to let the compiler ensure we
cater to the updated semantics.  Do the same for bdrv_co_write_zeroes().
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Update bdrv_co_do_write_zeroes() to be byte-based, and select
between the new byte-based bdrv_co_pwrite_zeroes() or the old
bdrv_co_write_zeroes().  The next patches will convert drivers,
then remove the old interface.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Another step towards removing sector-based interfaces: convert
the maximum write and minimum alignment values from sectors to
bytes.  Rename the variables to let the compiler check that all
users are converted to the new semantics.

The maximum remains an int as long as BDRV_REQUEST_MAX_SECTORS
is constrained by INT_MAX (this means that we can't even
support a 2G write_zeroes, but just under it) - changing
operation lengths to unsigned or to 64-bits is a much bigger
audit, and debatable if we even want to do it (since at the
core, a 32-bit platform will still have ssize_t as its
underlying limit on write()).

Meanwhile, alignment is changed to 'uint32_t', since it makes no
sense to have an alignment larger than the maximum write, and
less painful to use an unsigned type with well-defined behavior
in bit operations than to have to worry about what happens if
a driver mistakenly supplies a negative alignment.

Add an assert that no one was trying to use sectors to get a
write zeroes larger than 2G, and therefore that a later conversion
to bytes won't be impacted by keeping the limit at 32 bits.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If hardware does not advertise a minimum zero/discard
alignment, we still want to guarantee that the block layer
will align requests to our blocks, rather than the arbitrary
512-byte BDRV sector size.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

is_zero_cluster() and is_zero_cluster_top_locked() are used only
by qcow2_co_write_zeroes().  The former is too broad (we don't
care if the sectors we are about to overwrite are non-zero, only
that all other sectors in the cluster are zero), so it needs to
be called up to twice but with smaller limits - rename it along
with adding the neeeded parameter.  The latter can be inlined for
more compact code.

The testsuite change shows that we now have a sparser top file
when an unaligned write_zeroes overwrites the only portion of
the backing file with data.

Based on a patch proposal by Denis V. Lunev.

CC: Denis V. Lunev <den@openvz.org>
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Add another test to 154, showing that we currently allocate a
data cluster in the top layer if any sector of the backing file
was allocated.  The next patch will optimize this case.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch follows guidelines of all other tracepoints in qcow2, like ones
in qcow2_co_writev. I think that they should dump values in the same
quantities or be changed all together.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1463476543-3087-4-git-send-email-den@openvz.org>
[eblake: typo fix in commit message]
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Unaligned requests will occupy only one cluster. This is true since the
previous commit. Simplify the code taking this consideration into
account.

In other words, the caller is now buggy if it ever passes us an unaligned
request that crosses cluster boundaries (the only requests that can cross
boundaries will be aligned).

There are no other changes so far.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NEric Blake <eblake@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1463476543-3087-3-git-send-email-den@openvz.org>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We should split requests even if they are less than write_zeroes_alignment.
For example we can have the following request:
  offset 62k
  size   4k
  write_zeroes_alignment 64k
The original code sent 1 request covering 2 qcow2 clusters, and resulted
in both clusters being allocated. But by splitting the request, we can
cater to the case where one of the two clusters can be zeroed as a
whole, for only 1 cluster allocated after the operation.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1463476543-3087-2-git-send-email-den@openvz.org>

[eblake: Avoid exceeding nb_sectors, hoist alignment checks out of
loop, and update testsuite to show that patch works]
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

trivial patches for 2016-06-07

# gpg: Signature made Tue 07 Jun 2016 16:20:52 BST
# gpg:                using RSA key 0xBEE59D74A4C3D7DB
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>"
# gpg:                 aka "Michael Tokarev <mjt@corpit.ru>"
# gpg:                 aka "Michael Tokarev <mjt@debian.org>"

* remotes/mjt/tags/pull-trivial-patches-2016-06-07: (51 commits)
  hbitmap: Use DIV_ROUND_UP
  qemu-timer: Use DIV_ROUND_UP
  linux-user: Use DIV_ROUND_UP
  slirp: Use DIV_ROUND_UP
  usb: Use DIV_ROUND_UP
  rocker: Use DIV_ROUND_UP
  SPICE: Use DIV_ROUND_UP
  audio: Use DIV_ROUND_UP
  xen: Use DIV_ROUND_UP
  crypto: Use DIV_ROUND_UP
  block: Use DIV_ROUND_UP
  qed: Use DIV_ROUND_UP
  qcow/qcow2: Use DIV_ROUND_UP
  parallels: Use DIV_ROUND_UP
  coccinelle: use macro DIV_ROUND_UP instead of (((n) + (d) - 1) /(d))
  thunk: Rename args and fields in host-target bitmask conversion code
  thunk: Drop unused NO_THUNK_TYPE_SIZE guards
  qemu-common.h: Drop WORDS_ALIGNED define
  host-utils: Prefer 'false' for bool type
  docs/multi-thread-compression: Fix wrong command string
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Acked-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>