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  1. Sep 29, 2021
    • Vladimir Sementsov-Ogievskiy's avatar
      block: use int64_t instead of uint64_t in driver read handlers · f7ef38dd
      Vladimir Sementsov-Ogievskiy authored 
      
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver read handlers parameters which are already 64bit to
signed type.

While being here, convert also flags parameter to be BdrvRequestFlags.

Now let's consider all callers. Simple

  git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?'

shows that's there three callers of driver function:

 bdrv_driver_preadv() in block/io.c, passes int64_t, checked by
   bdrv_check_qiov_request() to be non-negative.

 qcow2_load_vmstate() does bdrv_check_qiov_request().

 do_perform_cow_read() has uint64_t argument. And a lot of things in
 qcow2 driver are uint64_t, so converting it is big job. But we must
 not work with requests that don't satisfy bdrv_check_qiov_request(),
 so let's just assert it here.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

The only one such caller:

    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1);
    ...
    ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0);

in tests/unit/test-bdrv-drain.c, and it's OK obviously.

Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
[eblake: fix typos]
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
      f7ef38dd
  3. Mar 19, 2021
    • Hanna Reitz's avatar
      curl: Disconnect sockets from CURLState · 0f418a20
      Hanna Reitz authored 
      When a curl transfer is finished, that does not mean that CURL lets go
of all the sockets it used for it.  We therefore must not free a
CURLSocket object before CURL has invoked curl_sock_cb() to tell us to
remove it.  Otherwise, we may get a use-after-free, as described in this
bug report: https://bugs.launchpad.net/qemu/+bug/1916501

(Reproducer from that report:
  $ qemu-img convert -f qcow2 -O raw \
  https://download.cirros-cloud.net/0.4.0/cirros-0.4.0-x86_64-disk.img \
  out.img
)

(Alternatively, it might seem logical to force-drop all sockets that
have been used for a state when the respective transfer is done, kind of
like it is done now, but including unsetting the AIO handlers.
Unfortunately, doing so makes the driver just hang instead of crashing,
which seems to evidence that CURL still uses those sockets.)

Make the CURLSocket object independent of "its" CURLState by putting all
sockets into a hash table belonging to the BDRVCURLState instead of a
list that belongs to a CURLState.  Do not touch any sockets in
curl_clean_state().

Testing, it seems like all sockets are indeed gone by the time the curl
BDS is closed, so it seems like there really was no point in freeing any
socket just because a transfer is done.  libcurl does invoke
curl_sock_cb() with CURL_POLL_REMOVE for every socket it has.

Buglink: https://bugs.launchpad.net/qemu/+bug/1916501


Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Message-Id: <20210309130541.37540-3-mreitz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
      0f418a20
    • Hanna Reitz's avatar
      curl: Store BDRVCURLState pointer in CURLSocket · 3663dca4
      Hanna Reitz authored 
      
A socket does not really belong to any specific state.  We do not need
to store a pointer to "its" state in it, a pointer to the common
BDRVCURLState is sufficient.

Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Message-Id: <20210309130541.37540-2-mreitz@redhat.com>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
      3663dca4
  5. Jan 02, 2021
  7. Dec 11, 2020
  9. Jul 10, 2020
    • Markus Armbruster's avatar
      error: Eliminate error_propagate() with Coccinelle, part 1 · 668f62ec
      Markus Armbruster authored 
      
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
      668f62ec
    • Markus Armbruster's avatar
      qemu-option: Use returned bool to check for failure · 235e59cf
      Markus Armbruster authored 
      
The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for QemuOpts functions that now return true / false on success /
error.  Coccinelle script:

    @@
    identifier fun = {
        opts_do_parse, parse_option_bool, parse_option_number,
        parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
        qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
        qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
        qemu_opts_validate
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]
      235e59cf
  11. Mar 11, 2020
  13. Sep 16, 2019
  15. Jun 12, 2019
  17. Feb 25, 2019
  19. Jan 30, 2019
  21. Nov 05, 2018
  23. Sep 25, 2018
    • Richard W.M. Jones's avatar
      curl: Make sslverify=off disable host as well as peer verification. · 637fa44a
      Richard W.M. Jones authored 
      The sslverify setting is supposed to turn off all TLS certificate
checks in libcurl.  However because of the way we use it, it only
turns off peer certificate authenticity checks
(CURLOPT_SSL_VERIFYPEER).  This patch makes it also turn off the check
that the server name in the certificate is the same as the server
you're connecting to (CURLOPT_SSL_VERIFYHOST).

We can use Google's server at 8.8.8.8 which happens to have a bad TLS
certificate to demonstrate this:

$ ./qemu-img create -q -f qcow2 -b 'json: { "file.sslverify": "off", "file.driver": "https", "file.url": "https://8.8.8.8/foo" }' /var/tmp/file.qcow2
qemu-img: /var/tmp/file.qcow2: CURL: Error opening file: SSL: no alternative certificate subject name matches target host name '8.8.8.8'
Could not open backing image to determine size.

With this patch applied, qemu-img connects to the server regardless of
the bad certificate:

$ ./qemu-img create -q -f qcow2 -b 'json: { "file.sslverify": "off", "file.driver": "https", "file.url": "https://8.8.8.8/foo" }' /var/tmp/file.qcow2
qemu-img: /var/tmp/file.qcow2: CURL: Error opening file: The requested URL returned error: 404 Not Found

(The 404 error is expected because 8.8.8.8 is not actually serving a
file called "/foo".)

Of course the default (without sslverify=off) remains to always check
the certificate:

$ ./qemu-img create -q -f qcow2 -b 'json: { "file.driver": "https", "file.url": "https://8.8.8.8/foo" }' /var/tmp/file.qcow2
qemu-img: /var/tmp/file.qcow2: CURL: Error opening file: SSL: no alternative certificate subject name matches target host name '8.8.8.8'
Could not open backing image to determine size.

Further information about the two settings is available here:

https://curl.haxx.se/libcurl/c/CURLOPT_SSL_VERIFYPEER.html
https://curl.haxx.se/libcurl/c/CURLOPT_SSL_VERIFYHOST.html



Signed-off-by: default avatarRichard W.M. Jones <rjones@redhat.com>
Message-id: 20180914095622.19698-1-rjones@redhat.com
Signed-off-by: default avatarJeff Cody <jcody@redhat.com>
      637fa44a
  25. Jul 23, 2018
  27. Feb 09, 2018
  29. Feb 08, 2018
  31. Dec 18, 2017
  33. May 16, 2017
  35. May 09, 2017
  37. Mar 31, 2017