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2020-05-19blockdev: Split off basic bitmap operations for qemu-imgEric Blake2-0/+322
Upcoming patches want to add some basic bitmap manipulation abilities to qemu-img. But blockdev.o is too heavyweight to link into qemu-img (among other things, it would drag in block jobs and transaction support - qemu-img does offline manipulation, where atomicity is less important because there are no concurrent modifications to compete with), so it's time to split off the bare bones of what we will need into a new file block/monitor/bitmap-qmp-cmds.o. This is sufficient to expose 6 QMP commands for use by qemu-img (add, remove, clear, enable, disable, merge), as well as move the three helper functions touched in the previous patch. Regarding MAINTAINERS, the new file is automatically part of block core, but also makes sense as related to other dirty bitmap files. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513011648.166876-6-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19block: Make it easier to learn which BDS support bitmapsEric Blake4-0/+19
Upcoming patches will enhance bitmap support in qemu-img, but in doing so, it turns out to be nice to suppress output when persistent bitmaps make no sense (such as on a qcow2 v2 image). Add a hook to make this easier to query. This patch adds a new callback .bdrv_supports_persistent_dirty_bitmap, rather than trying to shoehorn the answer in via existing callbacks. In particular, while it might have been possible to overload .bdrv_co_can_store_new_dirty_bitmap to special-case a NULL input to answer whether any persistent bitmaps are supported, that is at odds with whether a particular bitmap can be stored (for example, even on an image that supports persistent bitmaps but has currently filled up the maximum number of bitmaps, attempts to store another one should fail); and the new functionality doesn't require coroutine safety. Similarly, we could have added one more piece of information to .bdrv_get_info, but then again, most callers to that function tend to already discard extraneous information, and making it a catch-all rather than a series of dedicated scalar queries hasn't really simplified life. In the future, when we improve the ability to look up bitmaps through a filter, we will probably also want to teach the block layer to automatically let filters pass this request on through. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513011648.166876-4-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-18block/block-copy: Simplify block_copy_do_copy()Philippe Mathieu-Daudé1-9/+3
block_copy_do_copy() is static, only used in block_copy_task_entry with the error_is_read argument set. No need to check for it, simplify. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200507121129.29760-3-philmd@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block/block-copy: Fix uninitialized variable in block_copy_task_entryPhilippe Mathieu-Daudé1-1/+1
Fix when building with -Os: CC block/block-copy.o block/block-copy.c: In function ‘block_copy_task_entry’: block/block-copy.c:428:38: error: ‘error_is_read’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 428 | t->call_state->error_is_read = error_is_read; | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~ Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200507121129.29760-2-philmd@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Drop @child_class from bdrv_child_perm()Max Reitz9-14/+4
Implementations should decide the necessary permissions based on @role. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-35-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole in remaining casesMax Reitz2-5/+10
These calls have no real use for the child role yet, but it will not harm to give one. Notably, the bdrv_root_attach_child() call in blockjob.c is left unmodified because there is not much the generic BlockJob object wants from its children. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-34-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use bdrv_default_perms()Max Reitz20-28/+23
bdrv_default_perms() can decide which permission profile to use based on the BdrvChildRole, so block drivers do not need to select it explicitly. The blkverify driver now no longer shares the WRITE permission for the image to verify. We thus have to adjust two places in test-block-iothread not to take it. (Note that in theory, blkverify should behave like quorum in this regard and share neither WRITE nor RESIZE for both of its children. In practice, it does not really matter, because blkverify is used only for debugging, so we might as well keep its permissions rather liberal.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-30-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use child_of_bds in remaining placesMax Reitz3-6/+17
Replace child_file by child_of_bds in all remaining places (excluding tests). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-28-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make filter drivers use child_of_bdsMax Reitz8-12/+22
Note that some filters have secondary children, namely blkverify (the image to be verified) and blklogwrites (the log). This patch does not touch those children. Note that for blkverify, the filtered child should not be format-probed. While there is nothing enforcing this here, in practice, it will not be: blkverify implements .bdrv_file_open. The block layer ensures (and in fact, asserts) that BDRV_O_PROTOCOL is set for every BDS whose driver implements .bdrv_file_open. This flag will then be bequeathed to blkverify's children, and they will thus (by default) not be probed either. ("By default" refers to the fact that blkverify's other child (the non-filtered one) will have BDRV_O_PROTOCOL force-unset, because that is what happens for all non-filtered children of non-format drivers.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-27-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make format drivers use child_of_bdsMax Reitz12-29/+50
Commonly, they need to pass the BDRV_CHILD_IMAGE set as the BdrvChildRole; but there are exceptions for drivers with external data files (qcow2 and vmdk). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-26-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make backing files child_of_bds childrenMax Reitz2-2/+3
Make all parents of backing files pass the appropriate BdrvChildRole. By doing so, we can switch their BdrvChildClass over to the generic child_of_bds, which will do the right thing when given a correct BdrvChildRole. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-24-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Switch child_format users to child_of_bdsMax Reitz2-4/+6
Both users (quorum and blkverify) use child_format for not-really-filtered children, so the appropriate BdrvChildRole in both cases is DATA. (Note that this will cause bdrv_inherited_options() to force-allow format probing.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-22-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18raw-format: Split raw_read_options()Max Reitz1-45/+65
Split raw_read_options() into one function that actually just reads the options, and another that applies them. This will allow us to detect whether the user has specified any options before attaching the file child (so we can decide on its role based on the options). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-21-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass parent_is_format to .inherit_options()Max Reitz2-2/+2
We plan to unify the generic .inherit_options() functions. The resulting common function will need to decide whether to force-enable format probing, force-disable it, or leave it as-is. To make this decision, it will need to know whether the parent node is a format node or not (because we never want format probing if the parent is a format node already (except for the backing chain)). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-9-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole to .inherit_options()Max Reitz2-2/+4
For now, all callers (effectively) pass 0 and no callee evaluates thie value. Later patches will change both. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-8-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass BdrvChildRole to bdrv_child_perm()Max Reitz9-7/+16
For now, all callers pass 0 and no callee evaluates this value. Later patches will change both. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-7-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add BdrvChildRole to BdrvChildMax Reitz25-33/+34
For now, it is always set to 0. Later patches in this series will ensure that all callers pass an appropriate combination of flags. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Rename BdrvChildRole to BdrvChildClassMax Reitz11-31/+33
This structure nearly only contains parent callbacks for child state changes. It cannot really reflect a child's role, because different roles may overlap (as we will see when real roles are introduced), and because parents can have custom callbacks even when the child fulfills a standard role. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add BlockDriver.is_formatMax Reitz13-0/+14
We want to unify child_format and child_file at some point. One of the important things that set format drivers apart from other drivers is that they do not expect other format nodes under them (except in the backing chain), i.e. we must not probe formats inside of formats. That means we need something on which to distinguish format drivers from others, and hence this flag. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Mark commit, mirror, blkreplay as filtersMax Reitz3-0/+5
The commit, mirror, and blkreplay block nodes are filters, so they should be marked as such. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-2-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use bdrv_make_empty() where possibleMax Reitz2-5/+2
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200429141126.85159-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18replication: Avoid blk_make_empty() on read-only childKevin Wolf1-2/+11
This is just a bandaid to keep tests/test-replication working after bdrv_make_empty() starts to assert that we're not trying to call it on a read-only child. For the real solution in the future, replication should not steal the BdrvChild from its backing file (this is never correct to do!), but instead have its own child node references, with the appropriate permissions. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use blk_make_empty() after commitsMax Reitz1-7/+9
bdrv_commit() already has a BlockBackend pointing to the BDS that we want to empty, it just has the wrong permissions. qemu-img commit has no BlockBackend pointing to the old backing file yet, but introducing one is simple. After this commit, bdrv_make_empty() is the only remaining caller of BlockDriver.bdrv_make_empty(). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200429141126.85159-5-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> [kwolf: Fixed up reference output for 098] Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add blk_make_empty()Max Reitz1-0/+10
Two callers of BlockDriver.bdrv_make_empty() remain that should not call this method directly. Both do not have access to a BdrvChild, but they can use a BlockBackend, so we add this function that lets them use it. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200429141126.85159-4-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block/replication.c: Avoid cancelling the job twiceLukas Straub1-0/+2
If qemu in colo secondary mode is stopped, it crashes because s->backup_job is canceled twice: First with job_cancel_sync_all() in qemu_cleanup() and then in replication_stop(). Fix this by assigning NULL to s->backup_job when the job completes so replication_stop() and replication_do_checkpoint() won't touch the job. Signed-off-by: Lukas Straub <lukasstraub2@web.de> Message-Id: <20200511090801.7ed5d8f3@luklap> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18mirror: Make sure that source and target size matchKevin Wolf1-9/+12
If the target is shorter than the source, mirror would copy data until it reaches the end of the target and then fail with an I/O error when trying to write past the end. If the target is longer than the source, the mirror job would complete successfully, but the target wouldn't actually be an accurate copy of the source image (it would contain some additional garbage at the end). Fix this by checking that both images have the same size when the job starts. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200511135825.219437-4-kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-15qom: Drop parameter @errp of object_property_add() & friendsMarkus Armbruster1-4/+2
The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]
2020-05-13block/block-copy: fix use-after-free of task pointerVladimir Sementsov-Ogievskiy1-1/+1
Obviously, we should g_free the task after trace point and offset update. Reported-by: Coverity (CID 1428756) Fixes: 4ce5dd3e9b5ee0fac18625860eb3727399ee965e Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200507183800.22626-1-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-13qcow2: add zstd cluster compressionDenis Plotnikov2-0/+176
zstd significantly reduces cluster compression time. It provides better compression performance maintaining the same level of the compression ratio in comparison with zlib, which, at the moment, is the only compression method available. The performance test results: Test compresses and decompresses qemu qcow2 image with just installed rhel-7.6 guest. Image cluster size: 64K. Image on disk size: 2.2G The test was conducted with brd disk to reduce the influence of disk subsystem to the test results. The results is given in seconds. compress cmd: time ./qemu-img convert -O qcow2 -c -o compression_type=[zlib|zstd] src.img [zlib|zstd]_compressed.img decompress cmd time ./qemu-img convert -O qcow2 [zlib|zstd]_compressed.img uncompressed.img compression decompression zlib zstd zlib zstd ------------------------------------------------------------ real 65.5 16.3 (-75 %) 1.9 1.6 (-16 %) user 65.0 15.8 5.3 2.5 sys 3.3 0.2 2.0 2.0 Both ZLIB and ZSTD gave the same compression ratio: 1.57 compressed image size in both cases: 1.4G Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> QAPI part: Acked-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20200507082521.29210-4-dplotnikov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-13qcow2: rework the cluster compression routineDenis Plotnikov1-11/+60
The patch enables processing the image compression type defined for the image and chooses an appropriate method for image clusters (de)compression. Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.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: <20200507082521.29210-3-dplotnikov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-13qcow2: introduce compression type featureDenis Plotnikov2-1/+132
The patch adds some preparation parts for incompatible compression type feature to qcow2 allowing the use different compression methods for image clusters (de)compressing. It is implied that the compression type is set on the image creation and can be changed only later by image conversion, thus compression type defines the only compression algorithm used for the image, and thus, for all image clusters. The goal of the feature is to add support of other compression methods to qcow2. For example, ZSTD which is more effective on compression than ZLIB. The default compression is ZLIB. Images created with ZLIB compression type are backward compatible with older qemu versions. Adding of the compression type breaks a number of tests because now the compression type is reported on image creation and there are some changes in the qcow2 header in size and offsets. The tests are fixed in the following ways: * filter out compression_type for many tests * fix header size, feature table size and backing file offset affected tests: 031, 036, 061, 080 header_size +=8: 1 byte compression type 7 bytes padding feature_table += 48: incompatible feature compression type backing_file_offset += 56 (8 + 48 -> header_change + feature_table_change) * add "compression type" for test output matching when it isn't filtered affected tests: 049, 060, 061, 065, 082, 085, 144, 182, 185, 198, 206, 242, 255, 274, 280 Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> QAPI part: Acked-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20200507082521.29210-2-dplotnikov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-08block: Drop unused .bdrv_has_zero_init_truncateEric Blake9-16/+0
Now that there are no clients of bdrv_has_zero_init_truncate, none of the drivers need to worry about providing it. What's more, this eliminates a source of some confusion: a literal reading of the documentation as written in ceaca56f and implemented in commit 1dcaf527 claims that a driver which returns 0 for bdrv_has_zero_init_truncate() must not return 1 for bdrv_has_zero_init(); this condition was violated for parallels, qcow, and sometimes for vdi, although in practice it did not matter since those drivers also lacked .bdrv_co_truncate. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-10-eblake@redhat.com> Acked-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08vhdx: Rework truncation logicEric Blake1-38/+51
The vhdx driver uses truncation for image growth, with a special case for blocks that already read as zero but which are only being partially written. But with a bit of rearranging, it's just as easy to defer the decision on whether truncation resulted in zeroes to the actual allocation attempt, reducing the number of places that still use bdrv_has_zero_init_truncate. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-9-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08parallels: Rework truncation logicEric Blake1-9/+16
The parallels driver tries to use truncation for image growth, but can only do so when reads are guaranteed as zero. Now that we have a way to request zero contents from truncation, we can defer the decision to actual allocation attempts rather than up front, reducing the number of places that still use bdrv_has_zero_init_truncate. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-8-eblake@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08ssh: Support BDRV_REQ_ZERO_WRITE for truncateEric Blake1-0/+4
Our .bdrv_has_zero_init_truncate can detect when the remote side always zero fills; we can reuse that same knowledge to implement BDRV_REQ_ZERO_WRITE by ignoring it when the server gives it to us for free. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-7-eblake@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08sheepdog: Support BDRV_REQ_ZERO_WRITE for truncateEric Blake1-0/+1
Our .bdrv_has_zero_init_truncate always returns 1 because sheepdog always 0-fills; we can use that same knowledge to implement BDRV_REQ_ZERO_WRITE by ignoring it. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-6-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08rbd: Support BDRV_REQ_ZERO_WRITE for truncateEric Blake1-0/+3
Our .bdrv_has_zero_init_truncate always returns 1 because rbd always 0-fills; we can use that same knowledge to implement BDRV_REQ_ZERO_WRITE by ignoring it. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-5-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08nfs: Support BDRV_REQ_ZERO_WRITE for truncateEric Blake1-0/+3
Our .bdrv_has_zero_init_truncate returns 1 if we detect that the OS always 0-fills; we can use that same knowledge to implement BDRV_REQ_ZERO_WRITE by ignoring it when the OS gives it to us for free. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-4-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08file-win32: Support BDRV_REQ_ZERO_WRITE for truncateEric Blake1-0/+3
When using bdrv_file, .bdrv_has_zero_init_truncate always returns 1; therefore, we can behave just like file-posix, and always implement BDRV_REQ_ZERO_WRITE by ignoring it since the OS gives it to us for free (note that file-posix.c had to use an 'if' because it shared code between regular files and block devices, but in file-win32.c, bdrv_host_device uses a separate .bdrv_file_open). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200428202905.770727-3-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08gluster: Drop useless has_zero_init callbackEric Blake1-14/+0
block.c already defaults to 0 if we don't provide a callback; there's no need to write a callback that always fails. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200428202905.770727-2-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08qcow2: Fix preallocation on block devicesMax Reitz1-2/+8
Calling bdrv_getlength() to get the pre-truncate file size will not really work on block devices, because they have always the same length, and trying to write beyond it will fail with a rather cryptic error message. Instead, we should use qcow2_get_last_cluster() and bdrv_getlength() only as a fallback. Before this patch: $ truncate -s 1G test.img $ sudo losetup -f --show test.img /dev/loop0 $ sudo qemu-img create -f qcow2 -o preallocation=full /dev/loop0 64M Formatting '/dev/loop0', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=full lazy_refcounts=off refcount_bits=16 qemu-img: /dev/loop0: Could not resize image: Failed to resize refcount structures: No space left on device With this patch: $ sudo qemu-img create -f qcow2 -o preallocation=full /dev/loop0 64M Formatting '/dev/loop0', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=full lazy_refcounts=off refcount_bits=16 qemu-img: /dev/loop0: Could not resize image: Failed to resize underlying file: Preallocation mode 'full' unsupported for this non-regular file So as you can see, it still fails, but now the problem is missing support on the block device level, so we at least get a better error message. Note that we cannot preallocate block devices on truncate by design, because we do not know what area to preallocate. Their length is always the same, the truncate operation does not change it. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200505141801.1096763-1-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08backup: Make sure that source and target size matchKevin Wolf2-6/+22
Since the introduction of a backup filter node in commit 00e30f05d, the backup block job crashes when the target image is smaller than the source image because it will try to write after the end of the target node without having BLK_PERM_RESIZE. (Previously, the BlockBackend layer would have caught this and errored out gracefully.) We can fix this and even do better than the old behaviour: Check that source and target have the same image size at the start of the block job and unshare BLK_PERM_RESIZE. (This permission was already unshared before the same commit 00e30f05d, but the BlockBackend that was used to make the restriction was removed without a replacement.) This will immediately error out when starting the job instead of only when writing to a block that doesn't exist in the target. Longer target than source would technically work because we would never write to blocks that don't exist, but semantically these are invalid, too, because a backup is supposed to create a copy, not just an image that starts with a copy. Fixes: 00e30f05de1d19586345ec373970ef4c192c6270 Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1778593 Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430142755.315494-4-kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08backup: Improve error for bdrv_getlength() failureKevin Wolf1-2/+2
bdrv_get_device_name() will be an empty string with modern management tools that don't use -drive. Use bdrv_get_device_or_node_name() instead so that the node name is used if the BlockBackend is anonymous. While at it, start with upper case to make the message consistent with the rest of the function. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200430142755.315494-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08vmdk: Flush only once in vmdk_L2update()Kevin Wolf1-2/+5
If we have a backup L2 table, we currently flush once after writing to the active L2 table and again after writing to the backup table. A single flush is enough and makes things a little less slow. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430133007.170335-6-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08vmdk: Don't update L2 table for zero write on zero clusterKevin Wolf1-1/+1
If a cluster is already zeroed, we don't have to call vmdk_L2update(), which is rather slow because it flushes the image file. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430133007.170335-5-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08vmdk: Fix partial overwrite of zero clusterKevin Wolf1-6/+12
When overwriting a zero cluster, we must not perform copy-on-write from the backing file, but from a zeroed buffer. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430133007.170335-4-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08vmdk: Fix zero cluster allocationKevin Wolf1-5/+7
m_data must contain valid data even for zero clusters when no cluster was allocated in the image file. Without this, zero writes segfault with images that have zeroed_grain=on. For zero writes, we don't want to allocate a cluster in the image file even in compressed files. Fixes: 524089bce43fd1cd3daaca979872451efa2cf7c6 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430133007.170335-3-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08vmdk: Rename VmdkMetaData.valid to new_allocationKevin Wolf1-4/+4
m_data is used for zero clusters even though valid == 0. It really only means that a new cluster was allocated in the image file. Rename it to reflect this. While at it, change it from int to bool, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200430133007.170335-2-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08qcow2: Avoid integer wraparound in qcow2_co_truncate()Alberto Garcia1-5/+7
After commit f01643fb8b47e8a70c04bbf45e0f12a9e5bc54de when an image is extended and BDRV_REQ_ZERO_WRITE is set then the new clusters are zeroized. The code however does not detect correctly situations when the old and the new end of the image are within the same cluster. The problem can be reproduced with these steps: qemu-img create -f qcow2 backing.qcow2 1M qemu-img create -f qcow2 -F qcow2 -b backing.qcow2 top.qcow2 qemu-img resize --shrink top.qcow2 520k qemu-img resize top.qcow2 567k In the last step offset - zero_start causes an integer wraparound. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200504155217.10325-1-berto@igalia.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-07block: luks: better error message when creating too large filesMaxim Levitsky1-4/+21
Currently if you attampt to create too large file with luks you get the following error message: Formatting 'test.luks', fmt=luks size=17592186044416 key-secret=sec0 qemu-img: test.luks: Could not resize file: File too large While for raw format the error message is qemu-img: test.img: The image size is too large for file format 'raw' The reason for this is that qemu-img checks for errono of the failure, and presents the later error when it is -EFBIG However crypto generic code 'swallows' the errno and replaces it with -EIO. As an attempt to make it better, we can make luks driver, detect -EFBIG and in this case present a better error message, which is what this patch does The new error message is: qemu-img: error creating test.luks: The requested file size is too large Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1534898 Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>