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2021-07-21qemu-img: Add --skip-broken-bitmaps for 'convert --bitmaps'Eric Blake
The point of 'qemu-img convert --bitmaps' is to be a convenience for actions that are already possible through a string of smaller 'qemu-img bitmap' sub-commands. One situation not accounted for already is that if a source image contains an inconsistent bitmap (for example, because a qemu process died abruptly before flushing bitmap state), the user MUST delete those inconsistent bitmaps before anything else useful can be done with the image. We don't want to delete inconsistent bitmaps by default: although a corrupt bitmap is only a loss of optimization rather than a corruption of user-visible data, it is still nice to require the user to opt in to the fact that they are aware of the loss of the bitmap. Still, requiring the user to check 'qemu-img info' to see whether bitmaps are consistent, then use 'qemu-img bitmap --remove' to remove offenders, all before using 'qemu-img convert', is a lot more work than just adding a knob 'qemu-img convert --bitmaps --skip-broken-bitmaps' which opts in to skipping the broken bitmaps. After testing the new option, also demonstrate the way to manually fix things (either deleting bad bitmaps, or re-creating them as empty) so that it is possible to convert without the option. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1946084 Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210709153951.2801666-4-eblake@redhat.com> [eblake: warning message tweak, test enhancements] Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-07-12qemu-img: Reword 'qemu-img map --output=json' docsEric Blake
Reword the paragraphs to list the JSON key first, rather than in the middle of prose. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210707184125.2551140-1-eblake@redhat.com> Reviewed-by: Nir Soffer <nsoffer@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2021-07-12qemu-img: Make unallocated part of backing chain obvious in mapEric Blake
The recently-added NBD context qemu:allocation-depth is able to distinguish between locally-present data (even when that data is sparse) [shown as depth 1 over NBD], and data that could not be found anywhere in the backing chain [shown as depth 0]; and the libnbd project was recently patched to give the human-readable name "absent" to an allocation-depth of 0. But qemu-img map --output=json predates that addition, and has the unfortunate behavior that all portions of the backing chain that resolve without finding a hit in any backing layer report the same depth as the final backing layer. This makes it harder to reconstruct a qcow2 backing chain using just 'qemu-img map' output, especially when using "backing":null to artificially limit a backing chain, because it is impossible to distinguish between a QCOW2_CLUSTER_UNALLOCATED (which defers to a [missing] backing file) and a QCOW2_CLUSTER_ZERO_PLAIN cluster (which would override any backing file), since both types of clusters otherwise show as "data":false,"zero":true" (but note that we can distinguish a QCOW2_CLUSTER_ZERO_ALLOCATED, which would also have an "offset": listing). The task of reconstructing a qcow2 chain was made harder in commit 0da9856851 (nbd: server: Report holes for raw images), because prior to that point, it was possible to abuse NBD's block status command to see which portions of a qcow2 file resulted in BDRV_BLOCK_ALLOCATED (showing up as NBD_STATE_ZERO in isolation) vs. missing from the chain (showing up as NBD_STATE_ZERO|NBD_STATE_HOLE); but now qemu reports more accurate sparseness information over NBD. An obvious solution is to make 'qemu-img map --output=json' add an additional "present":false designation to any cluster lacking an allocation anywhere in the chain, without any change to the "depth" parameter to avoid breaking existing clients. The iotests have several examples where this distinction demonstrates the additional accuracy. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210701190655.2131223-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [eblake: fix more iotest fallout] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-05-14Document qemu-img options data_file and data_file_rawConnor Kuehl
The contents of this patch were initially developed and posted by Han Han[1], however, it appears the original patch was not applied. Since then, the relevant documentation has been moved and adapted to a new format. I've taken most of the original wording and tweaked it according to some of the feedback from the original patch submission. I've also adapted it to restructured text, which is the format the documentation currently uses. [1] https://lists.nongnu.org/archive/html/qemu-block/2019-10/msg01253.html Fixes: https://bugzilla.redhat.com/1763105 Signed-off-by: Han Han <hhan@redhat.com> Suggested-by: Max Reitz <mreitz@redhat.com> [ Max: provided description of data_file_raw behavior ] Signed-off-by: Connor Kuehl <ckuehl@redhat.com> Message-Id: <20210505195512.391128-1-ckuehl@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2021-03-19qemu-img: Use user_creatable_process_cmdline() for --objectKevin Wolf
This switches qemu-img from a QemuOpts-based parser for --object to user_creatable_process_cmdline() which uses a keyval parser and enforces the QAPI schema. Apart from being a cleanup, this makes non-scalar properties accessible. As a side effect, fix wrong exit codes in the object parsing error path of 'qemu-img compare'. This was broken in commit 334c43e2c3 because &error_fatal exits with an exit code of 1, while it should have been 2. Document that exit code 0 is also returned when just requested help was printed instead of comparing images. This is preexisting behaviour that isn't changed by this patch, though another instance of it is added with '--object help'. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2020-10-27qemu-img: add support for rate limit in qemu-img convertZhengui
add support for rate limit in qemu-img convert. Signed-off-by: Zhengui <lizhengui@huawei.com> Message-Id: <1603205264-17424-3-git-send-email-lizhengui@huawei.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-27qemu-img: add support for rate limit in qemu-img commitZhengui
add support for rate limit in qemu-img commit. Signed-off-by: Zhengui <lizhengui@huawei.com> Message-Id: <1603205264-17424-2-git-send-email-lizhengui@huawei.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14qcow2: Deprecate use of qemu-img amend to change backing fileEric Blake
The use of 'qemu-img amend' to change qcow2 backing files is not tested very well. In particular, our implementation has a bug where if a new backing file is provided without a format, then the prior format is blindly reused, even if this results in data corruption, but this is not caught by iotests. There are also situations where amending other options needs access to the original backing file (for example, on a downgrade to a v2 image, knowing whether a v3 zero cluster must be allocated or may be left unallocated depends on knowing whether the backing file already reads as zero), but the command line does not have a nice way to tell us both the backing file to use for opening the image as well as the backing file to install after the operation is complete. Even if we do allow changing the backing file, it is redundant with the existing ability to change backing files via 'qemu-img rebase -u'. It is time to deprecate this support (leaving the existing behavior intact, even if it is buggy), and at a point in the future, require the use of only 'qemu-img rebase' for adjusting backing chain relations, saving 'qemu-img amend' for changes unrelated to the backing chain. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-8-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-06block/amend: add 'force' optionMaxim Levitsky
'force' option will be used for some unsafe amend operations. This includes things like erasing last keyslot in luks based formats (which destroys the data, unless the master key is backed up by external means), but that _might_ be desired result. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200608094030.670121-4-mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-06-09qemu-img: Fix doc typo for 'bitmap' subcommandEric Blake
Prefer a consistent naming for the --merge argument. Fixes: 3b51ab4bf Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200529144527.1943527-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-28qemu-img: Add convert --bitmaps optionEric Blake
Make it easier to copy all the persistent bitmaps of (the top layer of) a source image along with its guest-visible contents, by adding a boolean flag for use with qemu-img convert. This is basically shorthand, as the same effect could be accomplished with a series of 'qemu-img bitmap --add' and 'qemu-img bitmap --merge -b source' commands, or by their corresponding QMP commands. Note that this command will fail in the same scenarios where 'qemu-img measure' omits a 'bitmaps size:' line, namely, when either the source or the destination lacks persistent bitmap support altogether. See also https://bugzilla.redhat.com/show_bug.cgi?id=1779893 While touching this, clean up a couple coding issues spotted in the same function: an extra blank line, and merging back-to-back 'if (!skip_create)' blocks. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200521192137.1120211-5-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-28qcow2: Expose bitmaps' size during measureEric Blake
It's useful to know how much space can be occupied by qcow2 persistent bitmaps, even though such metadata is unrelated to the guest-visible data. Report this value as an additional QMP field, present when measuring an existing image and output format that both support bitmaps. Update iotest 178 and 190 to updated output, as well as new coverage in 190 demonstrating non-zero values made possible with the recently-added qemu-img bitmap command (see 3b51ab4b). The new 'bitmaps size:' field is displayed automatically as part of 'qemu-img measure' any time it is present in QMP (that is, any time both the source image being measured and destination format support bitmaps, even if the measurement is 0 because there are no bitmaps present). If the field is absent, it means that no bitmaps can be copied (source, destination, or both lack bitmaps, including when measuring based on size rather than on a source image). This behavior is compatible with an upcoming patch adding 'qemu-img convert --bitmaps': that command will fail in the same situations where this patch omits the field. The addition of a new field demonstrates why we should always zero-initialize qapi C structs; while the qcow2 driver still fully populates all fields, the raw and crypto drivers had to be tweaked to avoid uninitialized data. Consideration was also given towards having a 'qemu-img measure --bitmaps' which errors out when bitmaps are not possible, and otherwise sums the bitmaps into the existing allocation totals rather than displaying as a separate field, as a potential convenience factor. But this was ultimately decided to be more complexity than necessary when the QMP interface was sufficient enough with bitmaps remaining a separate field. See also: https://bugzilla.redhat.com/1779904 Reported-by: Nir Soffer <nsoffer@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200521192137.1120211-3-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19qemu-img: Add bitmap sub-commandEric Blake
Include actions for --add, --remove, --clear, --enable, --disable, and --merge (note that --clear is a bit of fluff, because the same can be accomplished by removing a bitmap and then adding a new one in its place, but it matches what QMP commands exist). Listing is omitted, because it does not require a bitmap name and because it was already possible with 'qemu-img info'. A single command line can play one or more bitmap commands in sequence on the same bitmap name (although all added bitmaps share the same granularity, and and all merged bitmaps come from the same source file). Merge defaults to other bitmaps in the primary image, but can also be told to merge bitmaps from a distinct image. While this supports --image-opts for the file being modified, I did not think it worth the extra complexity to support that for the source file in a cross-file merges. Likewise, I chose to have --merge only take a single source rather than following the QMP support for multiple merges in one go (although you can still use more than one --merge in the command line); in part because qemu-img is offline and therefore atomicity is not an issue. Upcoming patches will add iotest coverage of these commands while also testing other features. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513011648.166876-7-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19docs: Sort sections on qemu-img subcommand parametersEric Blake
We already list the subcommand summaries alphabetically, we should do the same for the documentation related to subcommand-specific parameters. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513011648.166876-2-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-18qemu-img: Add --start-offset and --max-length to mapEyal Moscovici
The mapping operation of large disks especially ones stored over a long chain of QCOW2 files can take a long time to finish. Additionally when mapping fails there was no way recover by restarting the mapping from the failed location. The new options, --start-offset and --max-length allows the user to divide these type of map operations into shorter independent tasks. Reviewed-by: Eric Blake <eblake@redhat.com> Acked-by: Mark Kanda <mark.kanda@oracle.com> Co-developed-by: Yoav Elnekave <yoav.elnekave@oracle.com> Signed-off-by: Yoav Elnekave <yoav.elnekave@oracle.com> Signed-off-by: Eyal Moscovici <eyal.moscovici@oracle.com> Message-Id: <20200513133629.18508-5-eyal.moscovici@oracle.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2020-02-25docs: Move tools documentation to tools manualPeter Maydell
Move the following tools documentation files to the new tools manual: docs/interop/qemu-img.rst docs/interop/qemu-nbd.rst docs/interop/virtfs-proxy-helper.rst docs/interop/qemu-trace-stap.rst docs/interop/virtiofsd.rst Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20200217155415.30949-4-peter.maydell@linaro.org