Many qemu-img subcommands only read the source file(s) once. For these
use cases, a full write-back cache is unnecessary and mainly clutters
host cache memory. Though this is generally no concern as cache memory
is freely available and can be scaled by the host OS, it may become a
concern with thin provisioning.

For these cases, it makes sense to allow users to freely specify the
source cache mode (e.g. use no cache at all).

This commit adds a new switch (-T) for the qemu-img subcommands check,
compare, convert and rebase to specify the cache to be used for source
images (the backing file in case of rebase).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_get_geometry() hides errors.  Use bdrv_nb_sectors() or
bdrv_getlength() instead where that's obviously inappropriate.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Chiefly so I don't have to do the error checking in quadruplicate in
the next commit.  Moreover, replacing the frequently updated
bs_sectors by an array assigned just once makes the code easier to
understand.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Instead of bdrv_getlength().  Replace variable output_length by
output_sectors.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

getchar() is a standard c library function which may return with failure
(e.g. -1), so like another platforms, also need check it under WIN32.

And make the related code match current qemu code styles, too.
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

In this case, 'ret' is already '-1', so need not do it again.
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

Now that all backend drivers are using QemuOpts, remove all
QEMUOptionParameter related codes.
Signed-off-by: NDong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Change block layer to support both QemuOpts and QEMUOptionParameter.
After this patch, it will change backend drivers one by one. At the end,
QEMUOptionParameter will be removed and only QemuOpts is kept.
Signed-off-by: NDong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The exit code 63 (check not supported by image format) was not even
documented in the comment above the check command in the source code;
add it, as it does indeed seem useful.

Also, document all of check's exit codes in the manpage.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reported-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

img_check() should report that the format of the given image does not
support checks even if JSON output is desired. JSON data is output to
stdout, as opposed to error messages, which are (in the case of
qemu-img) printed to stderr. Therefore, it is easy to distinguish
between the two.

Also, img_info() does already use error_report() for human-readable
messages even though JSON output is desired (through
collect_image_info_list()).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Introduced in commit 661a0f71.  Spotted by Coverity.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Introduced in commit a283cb6e; mostly harmless.  Spotted by Coverity.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

g_sequence_lookup is not supported by glib < 2.28. The usage
of g_sequence_lookup is not essential in this context (it's a
safeguard against duplicate values in the help message).
Removing the call enables the build on all platforms and
does not change the operation of the help function.
Signed-off-by: NMike Day <ncmike@ncultra.org>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If target block driver forces compression, qemu-img convert needs to
write by cluster size as well as "-c" option.

Particularly, this applies for converting to VMDK streamOptimized
format.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The help message for qemu-img lists the supported block formats, of
which there are 27 as of version 2.0.50. The formats are printed in
the order of their driver's position in a linked list, which appears
random. This patch prints the formats in sorted order, making it
easier to read and to find a specific format in the list.

[Added suggestions from Fam Zheng <famz@redhat.com> to declare variables
at the top of the scope in help() and to omit explicit cast for void*
opaque.
--Stefan]
Signed-off-by: NMike Day <ncmike@ncultra.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This allows qemu-img to print out version information, without
needing to print the long help wall of text.

While there, perform some minor whitespace cleanup, and remove the
unused option_index variable in the call to getopt_long().
Reported-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This fixes a bug introduced in commit ac1307ab, that caused the
'--help' option to not be recognized as a valid command, and not
print any help.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Previously, when there is a user error in argv parsing, qemu-img prints
help text and exits.

Add an error_exit function to print a helpful error message and a hint
to run 'qemu-img --help' for more information.

As a bonus, "qemu-img <cmd> --help" now has a more reasonable exit code
0.

In the future the help text should be split by sub command, and only
print the information for the specified command.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qemu-img used to use "image" as ID for all block devices. This means
that e.g. img_convert() ended up with potentially multiple source images
and one target image, all with the same ID. The next patch will catch
this and fail to open the block device.

This patch makes sure that qemu-img uses meaningful unique IDs for the
block devices it uses.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

This patch adds an errp parameter to bdrv_new() and updates all its
callers. The next patches will make use of this in order to check for
duplicate IDs. Most of the callers know that their ID is fine, so they
can simply assert that there is no error.

Behaviour doesn't change with this patch yet as bdrv_new() doesn't
actually assign errors to errp.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

qemu-img check --repair option accepts an argument. The argument to
--repair switch can either be 'all' or 'leak'. Fix the long option to
mandate argument with --repair switch.

The patch fixes following segmentation fault

Core was generated by `qemu-img check -f qcow2 --repair all t.qcow2'.
Program terminated with signal 11, Segmentation fault.
0  in img_check (argc=6, argv=0x7fffab9b8a10) at qemu-img.c:588
588	            if (!strcmp(optarg, "leaks")) {
(gdb) bt
  0  img_check (argc=6, argv=0x7fffab9b8a10) at qemu-img.c:588
  1  __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
  2  _start ()
(gdb)
Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>
Reviewed-by: NLeandro Dorileo <l@dorileo.org>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Initialise progress output only when the -p and -q options have already
been parsed, otherwise it's always disabled.
Reported-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

There is no dependency on windows.h, and the standard include files are
already included by qemu-common.h.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

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>

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>

Make bdrv_open() take a pointer to a BDS pointer, similarly to
bdrv_file_open(). If a pointer to a NULL pointer is given, bdrv_open()
will create a new BDS with an empty name; if the BDS pointer is not
NULL, that existing BDS will be reused (in the same way as bdrv_open()
already did).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

With this change, main() calls qemu_init_exec_dir and uses argv[0] to
init exec_dir. The saved value can be retrieved with
qemu_get_exec_dir later. It will be reused by module loading.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

error_is_set(&var) is the same as var != NULL, but it takes
whole-program analysis to figure that out.  Unnecessarily hard for
optimizers, static checkers, and human readers.  Dumb it down to
obvious.

Gets rid of several dozen Coverity false positives.

Note that the obvious form is already used in many places.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

This is a boiler-plate _nofail variant of qemu_opts_create. Remove and
use error_abort in call sites.

null/0 arguments needs to be added for the id and fail_if_exists fields
in affected callsites due to argument inconsistency between the normal and
no_fail variants.
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

the progress output is very bumpy if the input images contains
a significant portion of unallocated sectors. This patch
checks how much sectors are allocated a priori if progress
output is selected.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

when doing very large jobs updating the progress only every 2%
is too rare.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

this patch shortens requests to end at an aligned sector so that
the next request starts aligned.

[Squashed Peter's fix for bdrv_get_info() failure discussed on the
mailing list.
--Stefan]
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

since the convert process is basically a sync operation it might
be benificial in some case to change the hardcoded I/O buffer
size to a greater value.

This patch increases the I/O buffer size if the output
driver advertises an optimal transfer length or discard alignment
that is greater than the default buffer size of 2M.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

we currently do not check if a sector is allocated during convert.
This means if a sector is unallocated that we allocate a bounce
buffer of zeroes, find out its zero later and do not write it
in the best case. In the worst case this can lead to reading
blocks from a raw device (like iSCSI) altough we could easily
know via get_block_status that they are zero and simply skip them.

This patch also fixes the progress output not being at 100% after
a successful conversion.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>