Commit Graph

5 Commits

Author SHA1 Message Date
Eric Blake cf923b783e utils: Improve qemu_strtosz() to have 64 bits of precision
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>
2021-03-08 13:36:12 -06:00
Max Reitz bb24cdc5ef iotests/178: Pass value to invalid option
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>
2021-01-26 14:36:37 +01:00
Eric Blake ca01b7a641 iotests: Fix test 178
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>
2020-05-28 13:15:23 -05:00
Stefan Hajnoczi c3673dcf08 qemu-img: allow qemu-img measure --object without a filename
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>
2020-03-11 12:42:29 +01:00
Stefan Hajnoczi 32a1681adc iotests: add test 178 for qemu-img measure
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>
2017-07-11 17:45:01 +02:00