Inform a user in case qcow2_get_specific_info fails to obtain
QCOW2 image specific information. This patch is preliminary to
the one "qcow2: Add list of bitmaps to ImageInfoSpecificQCow2".
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1549638368-530182-2-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
On FreeBSD 11.2:
$ nbdkit memory size=1M --run './qemu-io -f raw -c "aio_write 0 512" $nbd'
Parsing error: non-numeric argument, or extraneous/unrecognized suffix -- aio_write
After main option parsing, we reinitialize optind so we can parse each
command. However reinitializing optind to 0 does not work on FreeBSD.
What happens when you do this is optind remains 0 after the option
parsing loop, and the result is we try to parse argv[optind] ==
argv[0] == "aio_write" as if it was the first parameter.
The FreeBSD manual page says:
In order to use getopt() to evaluate multiple sets of arguments, or to
evaluate a single set of arguments multiple times, the variable optreset
must be set to 1 before the second and each additional set of calls to
getopt(), and the variable optind must be reinitialized.
(From the rest of the man page it is clear that optind must be
reinitialized to 1).
The glibc man page says:
A program that scans multiple argument vectors, or rescans the same
vector more than once, and wants to make use of GNU extensions such as
'+' and '-' at the start of optstring, or changes the value of
POSIXLY_CORRECT between scans, must reinitialize getopt() by resetting
optind to 0, rather than the traditional value of 1. (Resetting to 0
forces the invocation of an internal initialization routine that
rechecks POSIXLY_CORRECT and checks for GNU extensions in optstring.)
This commit introduces an OS-portability function called
qemu_reset_optind which provides a way of resetting optind that works
on FreeBSD and platforms that use optreset, while keeping it the same
as now on other platforms.
Note that the qemu codebase sets optind in many other places, but in
those other places it's setting a local variable and not using getopt.
This change is only needed in places where we are using getopt and the
associated global variable optind.
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Message-id: 20190118101114.11759-2-rjones@redhat.com
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that all callers are passing all flag changes as QDict options,
the flags parameter is no longer necessary, so we can get rid of it.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When reopen_f() puts a block device in the reopen queue, some of the
new options are passed using a QDict, but others ("read-only" and the
cache options) are passed as flags.
This patch puts those flags in the QDict. This way the flags parameter
becomes redundant and we'll be able to get rid of it in a subsequent
patch.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Use %zu instead of %zd for unsigned numbers.
This fixes two error messages from the LSTM static code analyzer:
This argument should be of type 'ssize_t' but is of type 'unsigned long'
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
"qemu-io reopen" doesn't allow changing the writethrough setting of
the cache, but the check is wrong, causing an error even on a simple
reopen with the default parameters:
$ qemu-img create -f qcow2 hd.qcow2 1M
$ qemu-system-x86_64 -monitor stdio -drive if=virtio,file=hd.qcow2
(qemu) qemu-io virtio0 reopen
Cannot change cache.writeback: Device attached
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is basically what everything else in the qemu code base does, so we
can do it here, too.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20180509194302.21585-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
For qemu-io, a function returns an integer with two possible values: 0
for "qemu-io may continue execution", or 1 for "qemu-io should exit".
However, there is only a single command that returns 1, and that is
"quit".
So let's turn this case into a global variable instead so we can make
better use of the return value in a later patch.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20180509194302.21585-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add it
to the places that actually need it.
While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.
This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
The bdrv_reopen*() implementation doesn't like it if the graph is
changed between queuing nodes for reopen and actually reopening them
(one of the reasons is that queuing can be recursive).
So instead of draining the device only in bdrv_reopen_multiple(),
require that callers already drained all affected nodes, and assert this
in bdrv_reopen_queue().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Previously, the alloc command required that input parameters be
sector-aligned and clamped to 32 bits, because the underlying
bdrv_is_allocated used a 32-bit parameter and asserted aligned
inputs. But now that we have fixed block status to report a
64-bit bytes value, and to properly round requests on behalf of
guests, we can pass any values, and can use qemu-io to add
coverage that our rounding is correct regardless of the guest
alignment constraints.
Update iotest 177 to intentionally probe block status at
unaligned boundaries as well as with a bytes value that does not
map to 32-bit sectors, which also required tweaking the image
prep to leave an unallocated portion to the image under test.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-io provides a 'reopen' command that allows switching from writable
to read-only access. We need to make sure that we don't try to keep
write permissions to a BlockBackend that becomes read-only, otherwise
things are going to fail.
This requires a bdrv_drain() call because otherwise in-flight AIO
write requests could issue new internal requests while the permission
has already gone away, which would cause assertion failures. Draining
the queue doesn't break AIO requests in any new way, bdrv_reopen() would
drain it anyway only a few lines later.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
This allows qemu-iotests to test the switch between read-only and
read-write mode for block devices.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
blk_truncate() itself will pass that value to bdrv_truncate(), and all
callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF
for now.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.
Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated. For now,
the io.c layer still assert()s that all callers are sector-aligned
on input and that *pnum is sector-aligned on return to the caller,
but that can be relaxed when a later patch implements byte-based
block status. Therefore, this code adds usages like
DIV_ROUND_UP(,BDRV_SECTOR_SIZE) to callers that still want aligned
values, where the call might reasonbly give non-aligned results
in the future; on the other hand, no rounding is needed for callers
that should just continue to work with byte alignment.
For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_is_allocated(). But
some code, particularly bdrv_commit(), gets a lot simpler because it
no longer has to mess with sectors; also, it is now possible to pass
NULL if the caller does not care how much of the image is allocated
beyond the initial offset. Leave comments where we can further
simplify once a later patch eliminates the need for sector-aligned
requests through bdrv_is_allocated().
For ease of review, bdrv_is_allocated_above() will be tackled
separately.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related
functions (and some others) to 'int bytes', as they both refer to bytes.
This helps with code legibility.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Mixing byte offset and sector allocation counts is a bit
confusing. Also, reporting n/m sectors, where m decreases
according to the remaining size of the file, isn't really
adding any useful information; and reporting an offset at
both the front and end of the line, with large amounts of
whitespace, is pointless. Update the output to use byte
counts and shorter lines, then adjust the affected tests
(./check -qcow2 102, ./check -vpc 146).
Note that 'qemu-io map' is MUCH weaker than 'qemu-img map';
the former only shows which regions of the active layer are
allocated, without regards to where the allocation comes from
or whether the allocated portion is known to read as zero
(because it is using the weaker bdrv_is_allocated()); while the
latter (especially in --output=json mode) reports more details
from bdrv_get_block_status().
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170429191419.30051-4-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
For the 'alloc' command, accepting an offset in bytes but a length
in sectors, and reporting output in sectors, is confusing. Do
everything in bytes, and adjust the expected output accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170429191419.30051-3-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Several copy-and-pasted alignment checks exist in qemu-io, which
could use some minor improvements:
- Manual comparison against 0x1ff is not as clean as using our
alignment macros (QEMU_IS_ALIGNED) from osdep.h.
- The error messages aren't quite grammatically correct.
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170429191419.30051-2-eblake@redhat.com
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
qemu_coroutine_create associates @co to qemu_aio_context but we poll
blk's context below. If the coroutine yields, it may never get resumed
again.
Use bdrv_coroutine_enter to make sure we are starting the I/O on the
right context.
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
It would be a bug for a command with the CMD_NOFILE_OK or
CMD_FLAG_GLOBAL flags set to also set the ct->perms field,
because the former says "OK for a file not to be open"
but the latter is a check on a file.
Add an assertion in qemuio_add_command() so we can catch that
sort of buggy command definition immediately rather than it
being a bug that only manifests when a particular set of
command line options is used.
(Coverity gets confused about this (CID 1371723) and reports
that we might dereference a NULL blk pointer in this case,
because it can't tell that that code path never happens with
the cmdinfo_t that we have. This commit won't help unconfuse
it, but it does fix the underlying issue.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1490967529-4767-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
The HMP command 'qemu-io' is a bit tricky because it wants to work on
the original BlockBackend, but additional permissions could be required.
The details are explained in a comment in the code, but in summary, just
request whatever permissions the current qemu-io command needs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This will permit its use in parse_option_size().
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-24-git-send-email-armbru@redhat.com>
This makes qemu_strtosz(), qemu_strtosz_mebi() and
qemu_strtosz_metric() similar to qemu_strtoi64(), except negative
values are rejected.
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-23-git-send-email-armbru@redhat.com>
Change the qemu_strtosz() & friends to return -EINVAL when @endptr is
null and the conversion doesn't consume the string completely.
Matches how qemu_strtol() & friends work.
Only test_qemu_strtosz_simple() passes a null @endptr. No functional
change there, because its conversion consumes the string.
Simplify callers that use @endptr only to fail when it doesn't point
to '\0' to pass a null @endptr instead.
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-22-git-send-email-armbru@redhat.com>
Most callers of qemu_strtosz_suffix() pass QEMU_STRTOSZ_DEFSUFFIX_B.
Capture the pattern in new qemu_strtosz().
Inline qemu_strtosz_suffix() into its only remaining caller.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-17-git-send-email-armbru@redhat.com>
Passing a request size larger than BDRV_REQUEST_MAX_BYTES to any of the
I/O commands results in an error. While 'read' and 'write' handle the
error correctly, 'aio_read' and 'aio_write' hit an assertion:
blk_aio_read_entry: Assertion `rwco->qiov->size == acb->bytes' failed.
The reason is that the QEMU I/O code cannot handle request sizes
larger than BDRV_REQUEST_MAX_BYTES, so this patch makes qemu-io check
that all values are within range.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 79f66648c685929a144396bda24d13a207131dcf.1485878688.git.berto@igalia.com
[mreitz: Use BDRV_REQUEST_MAX_BYTES instead of INT_MAX]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Some files contain multiple #includes of the same header file.
Removed most of those unnecessary duplicate entries using
scripts/clean-includes.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Anand J <anand.indukala@gmail.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
After the next patch bdrv_drain_all will have to be called without holding any
AioContext. Prepare to do this by adding an AioContext argument to
bdrv_reopen_multiple.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
This is a preparatory patch, which continues the general trend of the
transition to the byte-based interfaces. bdrv_check_request() and
blk_check_request() are no longer used, thus we can remove them.
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Jeff Cody <jcody@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Change sector-based blk_discard(), blk_co_discard(), and
blk_aio_discard() to instead be byte-based blk_pdiscard(),
blk_co_pdiscard(), and blk_aio_pdiscard(). NBD gets a lot
simpler now that ignoring the unaligned portion of a
byte-based discard request is handled under the hood by
the block layer.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468624988-423-6-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
create_iovec() has a comment lamenting the lack of SIZE_T_MAX. Since
there actually is a SIZE_MAX, use it.
Two places use INT_MAX for checking the upper bound of a sector count
that is used as an argument for a blk_*() function (blk_discard() and
blk_write_compressed(), respectively). BDRV_REQUEST_MAX_SECTORS should
be used instead.
And finally, do_co_pwrite_zeroes() used to similarly check that the
sector count does not exceed INT_MAX. However, this function is now
backed by blk_co_pwrite_zeroes() which takes bytes as an argument
instead of sectors. Therefore, it should be the byte count that does not
exceed INT_MAX, not the sector count.
Signed-off-by: Max Reitz <mreitz@redhat.com>
In practice the entry argument is always known at creation time, and
it is confusing that sometimes qemu_coroutine_enter is used with a
non-NULL argument to re-enter a coroutine (this happens in
block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value
at creation time, for consistency with e.g. aio_bh_new.
Mostly done with the following semantic patch:
@ entry1 @
expression entry, arg, co;
@@
- co = qemu_coroutine_create(entry);
+ co = qemu_coroutine_create(entry, arg);
...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);
@ entry2 @
expression entry, arg;
identifier co;
@@
- Coroutine *co = qemu_coroutine_create(entry);
+ Coroutine *co = qemu_coroutine_create(entry, arg);
...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);
@ entry3 @
expression entry, arg;
@@
- qemu_coroutine_enter(qemu_coroutine_create(entry), arg);
+ qemu_coroutine_enter(qemu_coroutine_create(entry, arg));
@ reentry @
expression co;
@@
- qemu_coroutine_enter(co, NULL);
+ qemu_coroutine_enter(co);
except for the aforementioned few places where the semantic patch
stumbled (as expected) and for test_co_queue, which would otherwise
produce an uninitialized variable warning.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit 983a1600 changed the semantics of blk_write_zeroes() to
be byte-based rather than sector-based, but did not change the
name, which is an open invitation for other code to misuse the
function. Renaming to pwrite_zeroes() makes it more in line
with other byte-based interfaces, and will help make it easier
to track which remaining write_zeroes interfaces still need
conversion.
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Commit 093ea232 removed the ability for aio_read and aio_write
to artificially inflate the invalid statistics counters for
block devices, since it no longer flags unaligned offset or
length. Add 'aio_read -i' and 'aio_write -i' to restore
the ability, and update test 136 to use it.
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1463416983-28318-4-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Commit 770e0e0e [*] tried to add 'writev -f', but didn't tweak
the getopt() call to actually let it work. Likewise, commit
c2e001c missed implementing 'aio_write -u -z'. The latter commit
also introduced a leak of ctx.
[*] does it sound "ech0e" in here? :)
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1463416983-28318-2-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Since virtio-blk implements request merging itself these days, the only
remaining users are test cases for the function. That doesn't make the
function exactly useful any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Make it easier to control whether the BDRV_REQ_MAY_UNMAP flag
can be passed through a write_zeroes command, by adding the '-u'
flag to qemu-io 'write -z' and 'aio_write -z'. To be useful,
the device has to be opened with BDRV_O_UNMAP (done by default
in qemu-io, but can be made explicit with '-d unmap').
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1462677405-4752-7-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Make it easier to test block drivers with BDRV_REQ_FUA in
.supported_write_flags, by adding the '-f' flag to qemu-io to
conditionally pass the flag through to specific writes ('write',
'write -z', 'writev', 'aio_write', 'aio_write -z'). You'll want
to use 'qemu-io -t none' to actually make -f useful (as
otherwise, the default writethrough mode automatically sets the
FUA bit on every write).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1462677405-4752-6-git-send-email-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
There's no reason to require the user to specify a flag just so
they can pass in unaligned numbers. Keep 'read -p' and 'write -p'
as no-ops so that I don't have to hunt down and update all users
of qemu-io, but otherwise make their behavior default as 'read' and
'write'. Also fix 'write -z', 'readv', 'writev', 'writev',
'aio_read', 'aio_write', and 'aio_write -z'. For now, 'read -b',
'write -b', and 'write -c' still require alignment (and 'multiwrite',
but that's slated to die soon).
qemu-iotest 23 is updated to match, as the only test that was
previously explicitly expecting an error on an unaligned request.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1462677405-4752-5-git-send-email-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We require a C99 compiler; let's use it to express what we
really mean.
(Yes, we now have an instance of 'if (bool + bool + bool > 1)',
which, although semantically valid C, looks ugly; it gets
cleaned up later.)
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1462677405-4752-4-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
qemu-io is the last user of several sector-based interfaces.
This patch upgrades to the new interfaces under the hood,
then deletes the resulting dead code. Note that for maximum
back-compat, while the -p option is no longer required to get
blk_pread(), it is still needed to allow for unaligned access;
this is because qemu-iotest 23 relies on qemu-io rejecting
unaligned accesses without -p. A later patch may clean up the
interface to be more user-friendly, but it's better to separate
what's done under the hood from what the user sees.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Sector-based blk_write() should die; convert the one-off
variant blk_write_zeroes() to use an offset/count interface
instead. Likewise for blk_co_write_zeroes() and
blk_aio_write_zeroes().
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We have several block drivers that understand BDRV_REQ_FUA,
and emulate it in the block layer for the rest by a full flush.
But without a way to actually request BDRV_REQ_FUA during a
pass-through blk_pwrite(), FUA-aware block drivers like NBD are
forced to repeat the emulation logic of a full flush regardless
of whether the backend they are writing to could do it more
efficiently.
This patch just wires up a flags argument; followup patches
will actually make use of it in the NBD driver and in qemu-io.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The previous patches have successively made blk->enable_write_cache the
true source for the information whether a writethrough mode must be
implemented. The corresponding BDRV_O_CACHE_WB is only useless baggage
we're carrying around, so now's the time to remove it.
At the same time, we remove the 'cache.writeback' option parsing on the
BDS level as the only effect was setting the BDRV_O_CACHE_WB flag.
This change requires test cases that explicitly enabled the option to
drop it. Other than that and the change of the error message when
writethrough is enabled on the BDS level (from "Can't set writethrough
mode" to "doesn't support the option"), there should be no change in
behaviour.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
