Rather than open-coding two different ways to check for an unwanted
negative sign, reuse the same code in both functions. That way, if we
decide down the road to accept "-0" instead of rejecting it, we have
fewer places to change. Also, it means we now get ERANGE instead of
EINVAL for negative values in qemu_strtosz, which is reasonable for
what it represents. This in turn changes the expected output of a
couple of iotests.
The change is not quite complete: negative fractional scaled values
can trip us up. This will be fixed in a later patch addressing other
issues with fractional scaled values.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230522190441.64278-18-eblake@redhat.com>
We have multiple clients of qemu_strtosz (qemu-io, the opts visitor,
the keyval visitor), and it gets annoying that edge-case testing is
impacted by implicit rounding to 53 bits of precision due to parsing
with strtod(). As an example posted by Rich Jones:
$ nbdkit memory $(( 2**63 - 2**30 )) --run \
'build/qemu-io -f raw "$uri" -c "w -P 3 $(( 2**63 - 2**30 - 512 )) 512" '
write failed: Input/output error
because 9223372035781033472 got rounded to 0x7fffffffc0000000 which is
out of bounds.
It is also worth noting that our existing parser, by virtue of using
strtod(), accepts decimal AND hex numbers, even though test-cutils
previously lacked any coverage of the latter until the previous patch.
We do have existing clients that expect a hex parse to work (for
example, iotest 33 using qemu-io -c "write -P 0xa 0x200 0x400"), but
strtod() parses "08" as 8 rather than as an invalid octal number, so
we know there are no clients that depend on octal. Our use of
strtod() also means that "0x1.8k" would actually parse as 1536 (the
fraction is 8/16), rather than 1843 (if the fraction were 8/10); but
as this was not covered in the testsuite, I have no qualms forbidding
hex fractions as invalid, so this patch declares that the use of
fractions is only supported with decimal input, and enhances the
testsuite to document that.
Our previous use of strtod() meant that -1 parsed as a negative; now
that we parse with strtoull(), negative values can wrap around modulo
2^64, so we have to explicitly check whether the user passed in a '-';
and make it consistent to also reject '-0'. This has the minor effect
of treating negative values as EINVAL (with no change to endptr)
rather than ERANGE (with endptr advanced to what was parsed), visible
in the updated iotest output.
We also had no testsuite coverage of "1.1e0k", which happened to parse
under strtod() but is unlikely to occur in practice; as long as we are
making things more robust, it is easy enough to reject the use of
exponents in a strtod parse.
The fix is done by breaking the parse into an integer prefix (no loss
in precision), rejecting negative values (since we can no longer rely
on strtod() to do that), determining if a decimal or hexadecimal parse
was intended (with the new restriction that a fractional hex parse is
not allowed), and where appropriate, using a floating point fractional
parse (where we also scan to reject use of exponents in the fraction).
The bulk of the patch is then updates to the testsuite to match our
new precision, as well as adding new cases we reject (whether they
were rejected or inadvertently accepted before).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210211204438.1184395-3-eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
ccd3b3b811 has deprecated short-hand boolean options (i.e., options
with values). All options without values are interpreted as boolean
options, so this includes the invalid option "snapshot.foo" used in
iotest 178.
So after ccd3b3b811, 178 fails with:
+qemu-img: warning: short-form boolean option 'snapshot.foo' deprecated
+Please use snapshot.foo=on instead
Suppress that deprecation warning by passing some value to it (it does
not matter which, because the option is invalid anyway).
Fixes: ccd3b3b811
("qemu-option: warn for short-form boolean options")
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210126123834.115915-1-mreitz@redhat.com>
It's useful to know how much space can be occupied by qcow2 persistent
bitmaps, even though such metadata is unrelated to the guest-visible
data. Report this value as an additional QMP field, present when
measuring an existing image and output format that both support
bitmaps. Update iotest 178 and 190 to updated output, as well as new
coverage in 190 demonstrating non-zero values made possible with the
recently-added qemu-img bitmap command (see 3b51ab4b).
The new 'bitmaps size:' field is displayed automatically as part of
'qemu-img measure' any time it is present in QMP (that is, any time
both the source image being measured and destination format support
bitmaps, even if the measurement is 0 because there are no bitmaps
present). If the field is absent, it means that no bitmaps can be
copied (source, destination, or both lack bitmaps, including when
measuring based on size rather than on a source image). This behavior
is compatible with an upcoming patch adding 'qemu-img convert
--bitmaps': that command will fail in the same situations where this
patch omits the field.
The addition of a new field demonstrates why we should always
zero-initialize qapi C structs; while the qcow2 driver still fully
populates all fields, the raw and crypto drivers had to be tweaked to
avoid uninitialized data.
Consideration was also given towards having a 'qemu-img measure
--bitmaps' which errors out when bitmaps are not possible, and
otherwise sums the bitmaps into the existing allocation totals rather
than displaying as a separate field, as a potential convenience
factor. But this was ultimately decided to be more complexity than
necessary when the QMP interface was sufficient enough with bitmaps
remaining a separate field.
See also: https://bugzilla.redhat.com/1779904
Reported-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200521192137.1120211-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
A recent change to qemu-img changed expected error message output, but
178 takes long enough to execute that it does not get run by 'make
check' or './check -g quick'.
Fixes: 43d589b074
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200521192137.1120211-2-eblake@redhat.com>
In most qemu-img sub-commands the --object option only makes sense when
there is a filename. qemu-img measure is an exception because objects
may be referenced from the image creation options instead of an existing
image file. Allow --object without a filename.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200221112522.1497712-4-stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
When creating an image with preallocation "off" or "falloc", the first
block of the image is typically not allocated. When using Gluster
storage backed by XFS filesystem, reading this block using direct I/O
succeeds regardless of request length, fooling alignment detection.
In this case we fallback to a safe value (4096) instead of the optimal
value (512), which may lead to unneeded data copying when aligning
requests. Allocating the first block avoids the fallback.
Since we allocate the first block even with preallocation=off, we no
longer create images with zero disk size:
$ ./qemu-img create -f raw test.raw 1g
Formatting 'test.raw', fmt=raw size=1073741824
$ ls -lhs test.raw
4.0K -rw-r--r--. 1 nsoffer nsoffer 1.0G Aug 16 23:48 test.raw
And converting the image requires additional cluster:
$ ./qemu-img measure -f raw -O qcow2 test.raw
required size: 458752
fully allocated size: 1074135040
When using format like vmdk with multiple files per image, we allocate
one block per file:
$ ./qemu-img create -f vmdk -o subformat=twoGbMaxExtentFlat test.vmdk 4g
Formatting 'test.vmdk', fmt=vmdk size=4294967296 compat6=off hwversion=undefined subformat=twoGbMaxExtentFlat
$ ls -lhs test*.vmdk
4.0K -rw-r--r--. 1 nsoffer nsoffer 2.0G Aug 27 03:23 test-f001.vmdk
4.0K -rw-r--r--. 1 nsoffer nsoffer 2.0G Aug 27 03:23 test-f002.vmdk
4.0K -rw-r--r--. 1 nsoffer nsoffer 353 Aug 27 03:23 test.vmdk
I did quick performance test for copying disks with qemu-img convert to
new raw target image to Gluster storage with sector size of 512 bytes:
for i in $(seq 10); do
rm -f dst.raw
sleep 10
time ./qemu-img convert -f raw -O raw -t none -T none src.raw dst.raw
done
Here is a table comparing the total time spent:
Type Before(s) After(s) Diff(%)
---------------------------------------
real 530.028 469.123 -11.4
user 17.204 10.768 -37.4
sys 17.881 7.011 -60.7
We can see very clear improvement in CPU usage.
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827010528.8818-2-nsoffer@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The previous patch includes the LUKS payload overhead into the qemu-img
measure calculation for qcow2. Update qemu-iotests 178 to exercise this
new code path.
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190218104525.23674-3-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-10-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
