Writes are mirrored num_children times on num_children devices.
Signed-off-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Create the structure holding the quorum settings and write the minimal block
driver instanciation boilerplate.
Signed-off-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Quorum is a block filter mirroring writes to num_children children.
For reads quorum reads each children and does a vote.
If more than vote_threshold versions are identical the quorum is reached and
this winning version is returned to the guest. So quorum prevents bit corruption.
For high availability purpose minority errors are reported via QMP but the guest
does not see them.

This patch creates the driver C source file and introduces the structures that
will be used in asynchronous reads and writes.
Signed-off-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qdict_array_split() should terminate if it encounters both an entry with
a key of "%u" and entries with keys prefixed "%u." for the same index.

This patch adds a test for this case.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Test the new functionality of qdict_array_split(), that is, splitting
off single objects.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Currently, qdict_array_split() only splits off entries with a key prefix
of "%u.", packing them into a new QDict. This patch makes it support
entries with the plain key "%u" as well, directly putting them into the
new QList without creating a QDict.

If there is both an entry with a key of "%u" and other entries with keys
prefixed "%u." (for the same index), the function simply terminates.

To do this, this patch also adds a static function which tests whether a
given QDict contains any keys with the given prefix. This is used to test
whether entries with a key prefixed "%u." do exist in the source QDict
without modifying it.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In config_parse_qdict_section(), the QList returned by
qdict_array_split() is assumed to only contain QDicts. Currently, this
is true but it may (and will) change in the future. Therefore, check
whether the assumption actually holds.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

This patch allows using 'qemu-img $subcmd -o help' for the create,
convert and amend subcommands, without specifying the previously
required filename arguments.

Note that it's still allowed and meaningful to specify a filename: An
invocation like 'qemu-img create -o help sheepdog:foo' will also display
options that are provided by the Sheepdog driver.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Instead of ignoring all option values but the last one, multiple -o
options now have the same meaning as having a single option with all
settings in the order of their respective -o options.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Instead of ignoring all option values but the last one, multiple -o
options now have the same meaning as having a single option with all
settings in the order of their respective -o options.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

If you specified multiple -o options for qemu-img create, it would
silently ignore all but the last one. This patch fixes the problem.

Now multiple -o options has the same meaning as having a single option
with all settings in the order of their respective -o options.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

has_help_option() checks if any help option ('help' or '?') occurs
anywhere in an option string, so that things like 'cluster_size=4k,help'
are recognised.

is_valid_option_list() ensures that the option list doesn't have options
with leading commas or trailing unescaped commas.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Instead of just putting it in debugging output, we can now put the
value in an Error.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Returning "Wrong medium type" for an image that does not have a valid
header is a bit weird.  Improve the error by mentioning what format
was trying to open it.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Now that we can return the "right" errors, use the Error** parameter
to pass them back instead of just printing them.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This prepares for propagating errors from vmdk_open_sparse and
vmdk_open_desc_file up to the caller of vmdk_open.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Currently, we just try reading a VMDK file as both image and descriptor.
This makes it hard to choose which of the two attempts gave the best error.
We'll decide in advance if the file looks like an image or a descriptor,
and this patch is the first step to that end.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Before:
    $ ./qemu-io-old
    qemu-io-old> open -r -o driver=vvfat,fat-type=24,dir=i386-softmmu
    Valid FAT types are only 12, 16 and 32
    qemu-io-old: can't open device (null): Could not open image: Invalid argument

After:
    $ ./qemu-io
    qemu-io> open -r -o driver=vvfat,fat-type=24,dir=i386-softmmu
    qemu-io: can't open device (null): Valid FAT types are only 12, 16 and 32
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Currently, "gluster:///volname/img" and (using file. options)
"file.driver=gluster,file.filename=foo" will segfault.  Also,
"//host/volname/img" will be rejected, but it is a valid URL
that should be accepted just fine with "file.driver=gluster".
Accept all of these, by inferring missing transport and host
as TCP and localhost respectively.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Before:
    $ ./qemu-io-old
    qemu-io-old> open -r -o file.driver=iscsi,file.filename=foo
    Failed to parse URL : foo
    qemu-io-old: can't open device (null): Could not open 'foo': Invalid argument

After:
    $ ./qemu-io
    qemu-io> open -r -o file.driver=iscsi,file.filename=foo
    qemu-io: can't open device (null): Failed to parse URL : foo
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qemu-nbd is one of the few valid users of qerror_report_err.  Move
the error-reporting socket wrappers there.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Before:
    $ ./qemu-io-old
    qemu-io-old> open -r -o file.driver=nbd
    one of path and host must be specified.
    qemu-io-old: can't open device (null): Could not open image: Invalid argument
    $ ./qemu-io-old
    qemu-io-old> open -r -o file.driver=nbd,file.host=foo,file.path=bar
    path and host may not be used at the same time.
    qemu-io-old: can't open device (null): Could not open image: Invalid argument

After:
    $ ./qemu-io
    qemu-io> open -r -o file.driver=nbd
    qemu-io: can't open device (null): one of path and host must be specified.
    $ ./qemu-io
    qemu-io> open -r -o file.driver=nbd,file.host=foo,file.path=bar
    qemu-io: can't open device (null): path and host may not be used at the same time.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Before:
    $ qemu-io-old
    qemu-io-old> open -r -o file.driver=nbd
    qemu-io-old: can't open device (null): Could not open image: Invalid argument
    $ ./qemu-io-old
    qemu-io-old> open -r -o file.driver=nbd,file.host=foo,file.path=bar
    path and host may not be used at the same time.
    qemu-io-old: can't open device (null): Could not open image: Invalid argument

After:
    $ ./qemu-io
    qemu-io> open -r -o file.driver=nbd
    one of path and host must be specified.
    qemu-io: can't open device (null): Could not open image: Invalid argument
    $ ./qemu-io
    qemu-io> open -r -o file.driver=nbd,file.host=foo,file.path=bar
    path and host may not be used at the same time.
    qemu-io: can't open device (null): Could not open image: Invalid argument

Next patch will fix the error propagation.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This option is now unnecessary since specifying BDRV_O_PROTOCOL as flag
will do exactly the same.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The fail and success paths of bdrv_file_open() may be further shortened
by reusing code already existent in bdrv_open(). This includes
bdrv_file_open() not taking the reference to options which allows the
removal of QDECREF(options) in that function.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The fail paths of bdrv_file_open() and bdrv_open() naturally exhibit
similarities, thus it is possible to reuse the one from bdrv_open() and
shorten the one in bdrv_file_open() accordingly.

Also, setting bs->options in bdrv_file_open() is not necessary if it is
already done in bdrv_open().
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Change bdrv_file_open() to take a simple pointer to an already existing
BDS instead of an indirect one. The BDS will be created in bdrv_open()
if necessary.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Remove the reference parameter and the related handling code from
bdrv_file_open(), since it exists in bdrv_open() now as well.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Add the bdrv_open() option BDRV_O_PROTOCOL which results in passing the
call to bdrv_file_open(). Additionally, make bdrv_file_open() static and
therefore bdrv_open() the only way to call it.

Consequently, all existing calls to bdrv_file_open() have to be adjusted
to use bdrv_open() with the BDRV_O_PROTOCOL flag instead.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Allow bdrv_open() to handle references to existing block devices just as
bdrv_file_open() is already capable of.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>