qemu/tests/qemu-iotests/178.out.raw
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

160 lines
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QA output created by 178
== Input validation ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
qemu-img: Either --size N or one filename must be specified.
qemu-img: --size N cannot be used together with a filename.
qemu-img: At most one filename argument is allowed.
qemu-img: Either --size N or one filename must be specified.
qemu-img: --image-opts, -f, and -l require a filename argument.
qemu-img: --image-opts, -f, and -l require a filename argument.
qemu-img: --image-opts, -f, and -l require a filename argument.
qemu-img: Invalid option list: ,
qemu-img: Invalid parameter 'snapshot.foo'
qemu-img: Failed in parsing snapshot param 'snapshot.foo=bar'
qemu-img: --output must be used with human or json as argument.
qemu-img: Invalid image size specified. You may use k, M, G, T, P or E suffixes for
qemu-img: kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes.
qemu-img: Unknown file format 'foo'
== Size calculation for a new file (human) ==
required size: 0
fully allocated size: 0
required size: 2147483648
fully allocated size: 2147483648
required size: 68719476736
fully allocated size: 68719476736
required size: 274877906944
fully allocated size: 274877906944
required size: 1099511627776
fully allocated size: 1099511627776
required size: 2251799813685248
fully allocated size: 2251799813685248
required size: 8070450532247928832
fully allocated size: 8070450532247928832
== Empty raw input image (human) ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
required size: 0
fully allocated size: 0
converted image file size in bytes: 0
== raw input image with data (human) ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
required size: 1073741824
fully allocated size: 1073741824
wrote 512/512 bytes at offset 512
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 65536/65536 bytes at offset 65536
64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 64512/64512 bytes at offset 134217728
63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
required size: 1073741824
fully allocated size: 1073741824
converted image file size in bytes: 1073741824
== raw input image and preallocation (human) ==
required size: 1073741824
fully allocated size: 1073741824
converted image file size in bytes: 1073741824
== Fully-allocated raw input image (human) ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=8388608
wrote 8388608/8388608 bytes at offset 0
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
required size: 8388608
fully allocated size: 8388608
converted image file size in bytes: 8388608
== Size calculation for a new file (json) ==
{
"required": 0,
"fully-allocated": 0
}
{
"required": 2147483648,
"fully-allocated": 2147483648
}
{
"required": 68719476736,
"fully-allocated": 68719476736
}
{
"required": 274877906944,
"fully-allocated": 274877906944
}
{
"required": 1099511627776,
"fully-allocated": 1099511627776
}
{
"required": 2251799813685248,
"fully-allocated": 2251799813685248
}
{
"required": 8070450532247928832,
"fully-allocated": 8070450532247928832
}
== Empty raw input image (json) ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
{
"required": 0,
"fully-allocated": 0
}
converted image file size in bytes: 0
== raw input image with data (json) ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
{
"required": 1073741824,
"fully-allocated": 1073741824
}
wrote 512/512 bytes at offset 512
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 65536/65536 bytes at offset 65536
64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 64512/64512 bytes at offset 134217728
63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
{
"required": 1073741824,
"fully-allocated": 1073741824
}
converted image file size in bytes: 1073741824
== raw input image and preallocation (json) ==
{
"required": 1073741824,
"fully-allocated": 1073741824
}
converted image file size in bytes: 1073741824
== Fully-allocated raw input image (json) ==
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=8388608
wrote 8388608/8388608 bytes at offset 0
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
{
"required": 8388608,
"fully-allocated": 8388608
}
converted image file size in bytes: 8388608
*** done