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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>
2020-05-19blockdev: Split off basic bitmap operations for qemu-imgEric Blake
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>
2020-05-19blockdev: Promote several bitmap functions to non-staticEric Blake
The next patch will split blockdev.c, which will require accessing some previously-static functions from more than one .c file. But part of promoting a function to public is picking a naming scheme that does not reek of exposing too many internals (two of the three functions were named starting with 'do_'). To make future code motion easier, perform the function rename and non-static promotion into its own patch. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513011648.166876-5-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-05-19block: Make it easier to learn which BDS support bitmapsEric Blake
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>
2020-05-19qemu-img: Fix stale comments on doc locationEric Blake
Missed in commit e13c59fa. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513011648.166876-3-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>
2020-05-19bitmaps: Update maintainerEric Blake
Dirty bitmaps are important to incremental backups, including exposure over NBD where I'm already maintainer. Also, I'm aware that lately I have been doing as much code/review on bitmaps as John Snow who is trying to scale back in order to focus elsewhere; and many of the recent patches have come from Vladimir, who is also interested in taking on maintainer duties, but would like to start with co-maintainership. Therefore, it's time to revamp the ownership of this category, as agreed between the three of us. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200514180003.325406-1-eblake@redhat.com> Acked-by: John Snow <jsnow@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
2020-05-19Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into ↵Peter Maydell
staging Pull request # gpg: Signature made Tue 19 May 2020 09:00:32 BST # gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full] # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full] # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/block-pull-request: aio-posix: disable fdmon-io_uring when GSource is used aio-posix: don't duplicate fd handler deletion in fdmon_io_uring_destroy() tests/fuzz: Extract ioport_fuzz_qtest() method tests/fuzz: Extract pciconfig_fuzz_qos() method tests/fuzz: Remove unuseful/unused typedefs tests/fuzz: Add missing space in test description Makefile: List fuzz targets in 'make help' tests/fuzz/Makefile: Do not link code using unavailable devices Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-05-19Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into stagingPeter Maydell
Block layer patches: - Introduce real BdrvChildRole - blk/bdrv_make_empty() functions instead of calling callbacks directly - mirror: Make sure that source and target size match - block-copy: Fix uninitialized variable - block/replication: Avoid cancelling the job twice - ahci: Log lost IRQs - iotests: Run pylint and mypy in a testcase - iotests: log messages from notrun() # gpg: Signature made Mon 18 May 2020 18:05:32 BST # gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6 # gpg: issuer "kwolf@redhat.com" # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full] # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * remotes/kevin/tags/for-upstream: (52 commits) hw: Use QEMU_IS_ALIGNED() on parallel flash block size iotests/030: Reduce run time by unthrottling job earlier hw/ide/ahci: Log lost IRQs iotests: log messages from notrun() block/block-copy: Simplify block_copy_do_copy() block/block-copy: Fix uninitialized variable in block_copy_task_entry block: Drop @child_class from bdrv_child_perm() block: Pass BdrvChildRole in remaining cases block: Drop child_file block: Drop bdrv_format_default_perms() block: Make bdrv_filter_default_perms() static block: Use bdrv_default_perms() tests: Use child_of_bds instead of child_file block: Use child_of_bds in remaining places block: Make filter drivers use child_of_bds block: Make format drivers use child_of_bds block: Drop child_backing block: Make backing files child_of_bds children block: Drop child_format block: Switch child_format users to child_of_bds ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-05-18Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2020-05-18' into ↵Peter Maydell
staging nbd patches for 2020-05-20 - fix stranded fd in 'qemu-nbd -c /dev/nbd0' - add 'qemu-img map --start-offset --max-length' options # gpg: Signature made Mon 18 May 2020 17:29:56 BST # gpg: using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A # gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full] # gpg: aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full] # gpg: aka "[jpeg image of size 6874]" [full] # Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2 F3AA A7A1 6B4A 2527 436A * remotes/ericb/tags/pull-nbd-2020-05-18: iotests: Enhance 223 to cover qemu-img map improvements qemu-img: Add --start-offset and --max-length to map qemu-img: refactor dump_map_entry JSON format output qemu-img: validate image length in img_map qemu_img: add cvtnum_full to print error reports qemu-nbd: Close inherited stderr Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-05-18aio-posix: disable fdmon-io_uring when GSource is usedStefan Hajnoczi
The glib event loop does not call fdmon_io_uring_wait() so fd handlers waiting to be submitted build up in the list. There is no benefit is using io_uring when the glib GSource is being used, so disable it instead of implementing a more complex fix. This fixes a memory leak where AioHandlers would build up and increasing amounts of CPU time were spent iterating them in aio_pending(). The symptom is that guests become slow when QEMU is built with io_uring support. Buglink: https://bugs.launchpad.net/qemu/+bug/1877716 Fixes: 73fd282e7b6dd4e4ea1c3bbb3d302c8db51e4ccf ("aio-posix: add io_uring fd monitoring implementation") Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-by: Oleksandr Natalenko <oleksandr@redhat.com> Message-id: 20200511183630.279750-3-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-05-18aio-posix: don't duplicate fd handler deletion in fdmon_io_uring_destroy()Stefan Hajnoczi
The io_uring file descriptor monitoring implementation has an internal list of fd handlers that are pending submission to io_uring. fdmon_io_uring_destroy() deletes all fd handlers on the list. Don't delete fd handlers directly in fdmon_io_uring_destroy() for two reasons: 1. This duplicates the aio-posix.c AioHandler deletion code and could become outdated if the struct changes. 2. Only handlers with the FDMON_IO_URING_REMOVE flag set are safe to remove. If the flag is not set then something still has a pointer to the fd handler. Let aio-posix.c and its user worry about that. In practice this isn't an issue because fdmon_io_uring_destroy() is only called when shutting down so all users have removed their fd handlers, but the next patch will need this! Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-by: Oleksandr Natalenko <oleksandr@redhat.com> Message-id: 20200511183630.279750-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-05-18hw: Use QEMU_IS_ALIGNED() on parallel flash block sizePhilippe Mathieu-Daudé
Use the QEMU_IS_ALIGNED() macro to verify the flash block size is properly aligned. It is quicker to process when reviewing. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200511205246.24621-1-philmd@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18iotests/030: Reduce run time by unthrottling job earlierKevin Wolf
test_overlapping_3() throttles its active commit job so it can be sure the job is still busy when it checks that you can't start a conflicting streaming job. However, it only sets the commit job back to full speed when it is ready, which takes a few seconds while it's throttled. We can already reset the limit after having checked that block-stream returns an error and save these seconds. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200513100025.33543-1-kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18hw/ide/ahci: Log lost IRQsPhilippe Mathieu-Daudé
One might find interesting to look at AHCI IRQs. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20200504094858.5975-1-f4bug@amsat.org> Reviewed-by: John Snow <jsnow@redhat.com> Acked-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18iotests: log messages from notrun()John Snow
Shift the logging initialization up to occur prior to validation checks, so that notrun() messages still get printed to console. (Also, remove the "debugging messages active" message, because we don't need to see that hundreds of times per iotest suite run.) Signed-off-by: John Snow <jsnow@redhat.com> Message-Id: <20200514201614.19941-2-jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block/block-copy: Simplify block_copy_do_copy()Philippe Mathieu-Daudé
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-Daudé
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 Reitz
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 Reitz
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: Drop child_fileMax Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-33-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Drop bdrv_format_default_perms()Max Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-32-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make bdrv_filter_default_perms() staticMax Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-31-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use bdrv_default_perms()Max Reitz
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>
2020-05-18tests: Use child_of_bds instead of child_fileMax Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-29-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use child_of_bds in remaining placesMax Reitz
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 Reitz
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 Reitz
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: Drop child_backingMax Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-25-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Make backing files child_of_bds childrenMax Reitz
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: Drop child_formatMax Reitz
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-23-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Switch child_format users to child_of_bdsMax Reitz
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 Reitz
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: Add bdrv_default_perms()Max Reitz
This callback can be used by BDSs that use child_of_bds with the appropriate BdrvChildRole for their children. Also, make bdrv_format_default_perms() use it for child_of_bds children (just a temporary solution until we can drop bdrv_format_default_perms() altogether). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-20-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Relax *perms_for_storage for data childrenMax Reitz
We can be less restrictive about pure data children than those with metadata on them, so let bdrv_default_perms_for_storage() handle metadata children differently from pure data children. As explained in the code, the restrictions on metadata children are strictly stricter than those for pure data children, so in theory we just have to distinguish between pure-data and all other storage children (pure metadata or data+metadata). In practice, that is not obvious, though, so we have two independent code paths for metadata and for data children, and data+metadata children will go through both (without the path for data children doing anything meaningful). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-19-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pull out bdrv_default_perms_for_storage()Max Reitz
Right now, bdrv_format_default_perms() is used by format parents (generally). We want to switch to a model where most parents use a single BdrvChildClass, which then decides the permissions based on the child role. To do so, we have to split bdrv_format_default_perms() into separate functions for each such role. Note that bdrv_default_perms_for_storage() currently handles all DATA | METADATA children. A follow-up patch is going to split it further into one function for each case. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-18-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pull out bdrv_default_perms_for_cow()Max Reitz
Right now, bdrv_format_default_perms() is used by format parents (generally). We want to switch to a model where most parents use a single BdrvChildClass, which then decides the permissions based on the child role. To do so, we have to split bdrv_format_default_perms() into separate functions for each such role. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-17-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Distinguish paths in *_format_default_permsMax Reitz
bdrv_format_default_perms() has one code path for backing files, and one for storage files. We want to pull them out into their own functions, so make sure they are completely distinct before so the next patches will be a bit cleaner. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-16-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add child_of_bdsMax Reitz
Any current user of child_file, child_format, and child_backing can and should use this generic BdrvChildClass instead, as it can handle all of these cases. However, to be able to do so, the users must pass the appropriate BdrvChildRole when the child is created/attached. (The following commits will take care of that.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-15-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Unify bdrv_child_cb_detach()Max Reitz
Make bdrv_child_cb_detach() call bdrv_backing_detach() for children with a COW role (and drop the reverse call from bdrv_backing_detach()), so it can be used for any child (with a proper role set). Because so far no child has a proper role set, we need a temporary new callback for child_backing.detach that ensures bdrv_backing_detach() is called for all COW children that do not have their role set yet. (Also, move bdrv_child_cb_detach() down to group it with bdrv_inherited_options() and bdrv_child_cb_attach().) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-14-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Unify bdrv_child_cb_attach()Max Reitz
Make bdrv_child_cb_attach() call bdrv_backing_attach() for children with a COW role (and drop the reverse call from bdrv_backing_attach()), so it can be used for any child (with a proper role set). Because so far no child has a proper role set, we need a temporary new callback for child_backing.attach that ensures bdrv_backing_attach() is called for all COW children that do not have their role set yet. (Also, move bdrv_child_cb_attach() down to group it with bdrv_inherited_options().) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-13-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Use bdrv_inherited_options()Max Reitz
Let child_file's, child_format's, and child_backing's .inherit_options() implementations fall back to bdrv_inherited_options() to show that it would really work for all of these cases, if only the parents passed the appropriate BdrvChildRole and parent_is_format values. (Also, make bdrv_open_inherit(), the only place to explicitly call bdrv_backing_options(), call bdrv_inherited_options() instead.) This patch should incur only two visible changes, both for child_format children, both of which are effectively bug fixes: First, they no longer have discard=unmap set by default. This reason it was set is because bdrv_inherited_fmt_options() fell through to bdrv_protocol_options(), and that set it because "format drivers take care to send flushes and respect unmap policy". None of the drivers that use child_format for their children (quorum and blkverify) are format drivers, though, so this reasoning does not apply here. Second, they no longer have BDRV_O_NO_IO force-cleared. child_format was used solely for children that do not store any metadata and as such will not be accessed by their parents as long as those parents do not receive I/O themselves. Thus, such children should inherit BDRV_O_NO_IO. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-12-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Add generic bdrv_inherited_options()Max Reitz
After the series this patch belongs to, we want to have a common BdrvChildClass that encompasses all of child_file, child_format, and child_backing. Such a single class needs a single .inherit_options() implementation, and this patch introduces it. The next patch will show how the existing implementations can fall back to it just by passing appropriate BdrvChildRole and parent_is_format values. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-11-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Rename bdrv_inherited_options()Max Reitz
The other two .inherit_options implementations specify exactly for what case they are used in their name, so do it for this one as well. (The actual intention behind this patch is to follow it up with a generic bdrv_inherited_options() that works for all three cases.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-10-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Pass parent_is_format to .inherit_options()Max Reitz
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 Reitz
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 Reitz
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 Reitz
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: Add BdrvChildRole and BdrvChildRoleBitsMax Reitz
This mask will supplement BdrvChildClass when it comes to what role (or combination of roles) a child takes for its parent. It consists of BdrvChildRoleBits values (which is an enum). Because empty enums are not allowed, let us just start with it filled. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200513110544.176672-5-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18block: Rename BdrvChildRole to BdrvChildClassMax Reitz
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>