The blk_register_buf() API is an optimization hint that allows some
block drivers to avoid I/O buffer housekeeping or bounce buffers.

Add an -r option to register the I/O buffer so that qemu-io can be used
to test the blk_register_buf() API. The next commit will add a test that
uses the new option.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230207203719.242926-4-stefanha@redhat.com>

The block layer APIs use BdrvRequestFlags while qemu-io code uses int.
Although the code compiles and runs fine, BdrvRequestFlags is clearer
because it differentiates between other types of flags like bdrv_open()
flags.

This is purely refactoring.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230207203719.242926-3-stefanha@redhat.com>

In order to let qemu-img info present a block graph, add a parameter to
bdrv_node_info_dump() and bdrv_image_info_specific_dump() so that the
information of nodes below the root level can be given an indentation.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220620162704.80987-9-hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

When a block driver supports obtaining format-specific information, but
that object only contains optional fields, it is possible that none of
them are present, so that dump_qobject() (called by
bdrv_image_info_specific_dump()) will not print anything.

The callers of bdrv_image_info_specific_dump() put a header above this
information ("Format specific information:\n"), which will look strange
when there is nothing below.  Modify bdrv_image_info_specific_dump() to
print this header instead of its callers, and only if there is indeed
something to be printed.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220620162704.80987-2-hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

qemu-io's do_co_pwrite_zeroes is reinventing the coroutine wrapper
blk_pwrite_zeroes.  Just use the real thing directly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221215130225.476477-1-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Swap 'buf' and 'bytes' around for consistency with other I/O functions.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-11-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

Swap 'buf' and 'bytes' around for consistency with
blk_co_{pread,pwrite}(), and in preparation to implement these functions
using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression blk, offset, buf, bytes, flags; @@
    - blk_pread(blk, offset, buf, bytes, flags)
    + blk_pread(blk, offset, bytes, buf, flags)

    @@ expression blk, offset, buf, bytes, flags; @@
    - blk_pwrite(blk, offset, buf, bytes, flags)
    + blk_pwrite(blk, offset, bytes, buf, flags)

It had no effect on hw/block/nand.c, presumably due to the #if, so that
file was updated manually.

Overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-4-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

For consistency with other I/O functions, and in preparation to
implement it using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression blk, offset, buf, bytes; @@
    - blk_pread(blk, offset, buf, bytes)
    + blk_pread(blk, offset, buf, bytes, 0)

It had no effect on hw/block/nand.c, presumably due to the #if, so that
file was updated manually.

Overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-3-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

They currently return the value of their 'bytes' parameter on success.

Make them return 0 instead, for consistency with other I/O functions and
in preparation to implement them using generated_co_wrapper. This also
makes it clear that short reads/writes are not possible.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20220705161527.1054072-2-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

When writing zeroes can fall back to a slow write, permitting an
overly large request can become an amplification denial of service
attack in triggering a large amount of work from a small request.  But
the whole point of the no fallback flag is to quickly determine if
writing an entire device to zero can be done quickly (such as when it
is already known that the device started with zero contents); in those
cases, artificially capping things at 2G in qemu-io itself doesn't
help us.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211203231539.3900865-4-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

The block layer has supported 64-bit block status from drivers since
commit 86a3d5c6 ("block: Add .bdrv_co_block_status() callback",
v2.12) and friends, with individual driver callbacks responsible for
capping things where necessary.  Artificially capping things below 2G
in the qemu-io 'map' command, added in commit d6a644bb ("block: Make
bdrv_is_allocated() byte-based", v2.10) is thus no longer necessary.

One way to test this is with qemu-nbd as server on a raw file larger
than 4G (the entire file should show as allocated), plus 'qemu-io -f
raw -c map nbd://localhost

 --trace=nbd_\*' as client.  Prior to this
patch, the NBD_CMD_BLOCK_STATUS requests are fragmented at 0x7ffffe00
distances; with this patch, the fragmenting changes to 0x7fffffff
(since the NBD protocol is currently still limited to 32-bit
transactions - see block/nbd.c:nbd_client_co_block_status).  Then in
later patches, once I add an NBD extension for a 64-bit block status,
the same map command completes with just one NBD_CMD_BLOCK_STATUS.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211203231539.3900865-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Move the various memalign-related functions out of osdep.h and into
their own header, which we include only where they are used.
While we're doing this, add some brief documentation comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org

As the BlockReopenQueue can contain nodes in multiple AioContexts, only
one of which may be locked when AIO_WAIT_WHILE() can be called, we can't
let the caller lock the right contexts. Instead, individually lock the
AioContext of a single node when iterating the queue.

Reintroduce bdrv_reopen() as a wrapper for reopening a single node that
drains the node and temporarily drops the AioContext lock for
bdrv_reopen_multiple().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210708114709.206487-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Coverity thinks blk may be NULL. It's a false-positive, as described in
a new comment.

Fixes: Coverity CID 1453194
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210519090532.3753-1-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Max reported the following bug:

$ ./qemu-img create -f raw src.img 1G
$ ./qemu-img create -f raw dst.img 1G

$ (echo '
   {"execute":"qmp_capabilities"}
   {"execute":"blockdev-mirror",
    "arguments":{"job-id":"mirror",
                 "device":"source",
                 "target":"target",
                 "sync":"full",
                 "filter-node-name":"mirror-top"}}
'; sleep 3; echo '
   {"execute":"human-monitor-command",
    "arguments":{"command-line":
                 "qemu-io mirror-top \"write 0 1G\""}}') \
| x86_64-softmmu/qemu-system-x86_64 \
   -qmp stdio \
   -blockdev file,node-name=source,filename=src.img \
   -blockdev file,node-name=target,filename=dst.img \
   -object iothread,id=iothr0 \
   -device virtio-blk,drive=source,iothread=iothr0

crashes:

0  raise () at /usr/lib/libc.so.6
1  abort () at /usr/lib/libc.so.6
2  error_exit
   (err=<optimized out>,
   msg=msg@entry=0x55fbb1634790 <__func__.27> "qemu_mutex_unlock_impl")
   at ../util/qemu-thread-posix.c:37
3  qemu_mutex_unlock_impl
   (mutex=mutex@entry=0x55fbb25ab6e0,
   file=file@entry=0x55fbb1636957 "../util/async.c",
   line=line@entry=650)
   at ../util/qemu-thread-posix.c:109
4  aio_context_release (ctx=ctx@entry=0x55fbb25ab680) at ../util/async.c:650
5  bdrv_do_drained_begin
   (bs=bs@entry=0x55fbb3a87000, recursive=recursive@entry=false,
   parent=parent@entry=0x0,
   ignore_bds_parents=ignore_bds_parents@entry=false,
   poll=poll@entry=true) at ../block/io.c:441
6  bdrv_do_drained_begin
   (poll=true, ignore_bds_parents=false, parent=0x0, recursive=false,
   bs=0x55fbb3a87000) at ../block/io.c:448
7  blk_drain (blk=0x55fbb26c5a00) at ../block/block-backend.c:1718
8  blk_unref (blk=0x55fbb26c5a00) at ../block/block-backend.c:498
9  blk_unref (blk=0x55fbb26c5a00) at ../block/block-backend.c:491
10 hmp_qemu_io (mon=0x7fffaf3fc7d0, qdict=<optimized out>)
   at ../block/monitor/block-hmp-cmds.c:628

man pthread_mutex_unlock
...
    EPERM  The  mutex type is PTHREAD_MUTEX_ERRORCHECK or
    PTHREAD_MUTEX_RECURSIVE, or the mutex is a robust mutex, and the
    current thread does not own the mutex.

So, thread doesn't own the mutex. And we have iothread here.

Next, note that AIO_WAIT_WHILE() documents that ctx must be acquired
exactly once by caller. But where is it acquired in the call stack?
Seems nowhere.

qemuio_command do acquire aio context.. But we need context acquired
around blk_unref() as well and actually around blk_insert_bs() too.

Let's refactor qemuio_command so that it doesn't acquire aio context
but callers do that instead. This way we can cleanly acquire aio
context in hmp_qemu_io() around all three calls.

Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210423134233.51495-1-vsementsov@virtuozzo.com>
[mreitz: Fixed comment]
Signed-off-by: Max Reitz <mreitz@redhat.com>

This will be used in further test.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201021145859.11201-10-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

help_oneline is declared and starts as:

  static void help_oneline(const char *cmd, const cmdinfo_t *ct)
  {
      if (cmd) {
          printf("%s ", cmd);
      } else {
          printf("%s ", ct->name);
          if (ct->altname) {
              printf("(or %s) ", ct->altname);
          }
      }

However, there are only two routes to help_oneline being called:

   help_f -> help_all -> help_oneline(ct->name, ct)

   help_f -> help_onecmd(argv[1], ct)

In the first case, 'cmd' and 'ct->name' are the same thing,
so it's impossible for the if (cmd) to be false and then validly
print ct->name - this is upsetting gcc
( https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96739

 )

In the second case, cmd is argv[1] and we know we've got argv[1]
so again (cmd) is non-NULL.

Simplify help_oneline by just printing cmd.
(Also strengthen argc check just to be pedantic)

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200824102914.105619-1-dgilbert@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

When converting to qcow2 compressed format, the last step is a special
zero length compressed write, ending in a call to bdrv_co_truncate(). This
call always fails for the nbd driver since it does not implement
bdrv_co_truncate().

For block devices, which have the same limits, the call succeeds since
the file driver implements bdrv_co_truncate(). If the caller asked to
truncate to the same or smaller size with exact=false, the truncate
succeeds. Implement the same logic for nbd.

Example failing without this change:

In one shell start qemu-nbd:

$ truncate -s 1g test.tar
$ qemu-nbd --socket=/tmp/nbd.sock --persistent --format=raw --offset 1536 test.tar

In another shell convert an image to qcow2 compressed via NBD:

$ echo "disk data" > disk.raw
$ truncate -s 1g disk.raw
$ qemu-img convert -f raw -O qcow2 -c disk1.raw nbd+unix:///?socket=/tmp/nbd.sock; echo $?
1

qemu-img failed, but the conversion was successful:

$ qemu-img info nbd+unix:///?socket=/tmp/nbd.sock
image: nbd+unix://?socket=/tmp/nbd.sock
file format: qcow2
virtual size: 1 GiB (1073741824 bytes)
...

$ qemu-img check nbd+unix:///?socket=/tmp/nbd.sock
No errors were found on the image.
1/16384 = 0.01% allocated, 100.00% fragmented, 100.00% compressed clusters
Image end offset: 393216

$ qemu-img compare disk.raw nbd+unix:///?socket=/tmp/nbd.sock
Images are identical.

Fixes: https://bugzilla.redhat.com/1860627


Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-Id: <20200727215846.395443-2-nsoffer@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: typo fixes]
Signed-off-by: Eric Blake <eblake@redhat.com>

Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

This is a change in behavior, so all instances need a good
justification.  The comments added here should explain my reasoning.

qed already had a comment that suggests it always expected
bdrv_truncate()/blk_truncate() to behave as if exact=true were passed
(c743849b came eight months before 55b949c8), so it was simply
broken until now.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-8-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
[mreitz: Changed comment in qed.c to explain why a new QED file must be
         empty, as requested and suggested by Maxim]
Signed-off-by: Max Reitz <mreitz@redhat.com>

We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk.  Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.

This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around.  All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior.  Future patches take care
of that.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

qemu_io_alloc_from_file() needs to close the pattern file even if some
error occurred.

Setting f = NULL in the success path and checking it for NULL in the
error path isn't strictly necessary at this point, but let's do it
anyway in case someone later adds a 'goto error' after closing the file.

Coverity: CID 1405303
Fixes: 4d731510
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

The patch allows to provide a pattern file for write
command. There was no similar ability before.

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Message-id: 20190820164616.4072-1-dplotnikov@virtuozzo.com
Reviewed-by: Eric Blake <eblake@redhat.com>
[mreitz: Keep optstring in alphabetical order]
Signed-off-by: Max Reitz <mreitz@redhat.com>

The previous use of gettimeofday() ran into undefined behaviour when
we ended up doing a div 0 for a very short operation. This is because
gettimeofday only works at the microsecond level as well as being
prone to discontinuous jumps in system time. Using clock_gettime with
CLOCK_MONOTONIC gives greater precision and alleviates some of the
potential problems with time jumping around.

We could use CLOCK_MONOTONIC_RAW to avoid being tripped up by NTP and
adjtime but that is Linux specific so I decided it would do for now.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

There are a few places in which we turn a number of bytes into sectors
in order to compare the result against BDRV_REQUEST_MAX_SECTORS
instead of using BDRV_REQUEST_MAX_BYTES directly.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

bdrv_snapshot_dump(), bdrv_image_info_specific_dump(),
bdrv_image_info_dump() and their helpers take an fprintf()-like
callback and a FILE * to pass to it.

hmp.c passes monitor_printf() cast to fprintf_function and the current
monitor cast to FILE *.

qemu-img.c and qemu-io-cmds.c pass fprintf and stdout.

The type-punning is technically undefined behaviour, but works in
practice.  Clean up: drop the callback, and call qemu_printf()
instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-8-armbru@redhat.com>

This makes the new BDRV_REQ_NO_FALLBACK flag available in the qemu-io
write command.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Eric Blake <eblake@redhat.com>

This parameter has been unused since 1a63a907

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

The bdrv_reopen_queue() function is used to create a queue with
the BDSs that are going to be reopened and their new options. Once
the queue is ready bdrv_reopen_multiple() is called to perform the
operation.

The original options from each one of the BDSs are kept, with the new
options passed to bdrv_reopen_queue() applied on top of them.

For "x-blockdev-reopen" we want a function that behaves much like
"blockdev-add". We want to ignore the previous set of options so that
only the ones actually specified by the user are applied, with the
rest having their default values.

One of the things that we need is a way to tell bdrv_reopen_queue()
whether we want to keep the old set of options or not, and that's what
this patch does. All current callers are setting this new parameter to
true and x-blockdev-reopen will set it to false.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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 bdd6a90a 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>