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2021-02-15block: add bdrv_co_delete_file_noerrMaxim Levitsky
This function wraps bdrv_co_delete_file for the common case of removing a file, which was just created by format driver, on an error condition. It hides the -ENOTSUPP error, and reports all other errors otherwise. Use it in luks driver Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20201217170904.946013-3-mlevitsk@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-02-13Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2021-02-12' ↵Peter Maydell
into staging bitmaps patches for 2021-02-12 - add 'transform' member to manipulate bitmaps across migration - work towards better error handling during bdrv_open # gpg: Signature made Fri 12 Feb 2021 23:19:39 GMT # 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-bitmaps-2021-02-12: block: use return status of bdrv_append() block: return status from bdrv_append and friends qemu-iotests: 300: Add test case for modifying persistence of bitmap migration: dirty-bitmap: Allow control of bitmap persistence migration: dirty-bitmap: Use struct for alias map inner members Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-02-12block: return status from bdrv_append and friendsVladimir Sementsov-Ogievskiy
The recommended use of qemu error api assumes returning status together with setting errp and avoid void functions with errp parameter. Let's improve bdrv_append and some friends to reduce error-propagation overhead in further patches. Choose int return status, because bdrv_replace_node_common() has call to bdrv_check_update_perm(), which reports int status, which seems correct to propagate. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210202124956.63146-2-vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-02-12block: add new BlockDriver handler: bdrv_cancel_in_flightVladimir Sementsov-Ogievskiy
It will be used to stop retrying NBD requests on mirror cancel. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20210205163720.887197-2-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-02-03block/io: use int64_t bytes in copy_rangeVladimir Sementsov-Ogievskiy
We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert now copy_range parameters which are already 64bit to signed type. It's safe as we don't work with requests overflowing BDRV_MAX_LENGTH (which is less than INT64_MAX), and do check the requests in bdrv_co_copy_range_internal() (by bdrv_check_request32(), which calls bdrv_check_request()). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20201211183934.169161-17-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-02-03block/io: support int64_t bytes in read/write wrappersVladimir Sementsov-Ogievskiy
We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). Now, since bdrv_co_preadv_part() and bdrv_co_pwritev_part() have been updated, update all their wrappers. For all of them type of 'bytes' is widening, so callers are safe. We have update request_fn in blkverify.c simultaneously. Still it's just a pointer to one of bdrv_co_pwritev() or bdrv_co_preadv(), and type is widening for callers of the request_fn anyway. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20201211183934.169161-16-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: grammar tweak] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-01-26copy-on-read: skip non-guest reads if no copy neededAndrey Shinkevich
If the flag BDRV_REQ_PREFETCH was set, skip idling read/write operations in COR-driver. It can be taken into account for the COR-algorithms optimization. That check is being made during the block stream job by the moment. Add the BDRV_REQ_PREFETCH flag to the supported_read_flags of the COR-filter. block: Modify the comment for the flag BDRV_REQ_PREFETCH as we are going to use it alone and pass it to the COR-filter driver for further processing. Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201216061703.70908-9-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2021-01-26block: add API function to insert a nodeAndrey Shinkevich
Provide API for insertion a node to backing chain. Suggested-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201216061703.70908-3-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-12-18block: introduce BDRV_REQ_NO_WAIT flagVladimir Sementsov-Ogievskiy
Add flag to make serialising request no wait: if there are conflicting requests, just return error immediately. It's will be used in upcoming preallocate filter. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201021145859.11201-7-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-12-18block: simplify comment to BDRV_REQ_SERIALISINGVladimir Sementsov-Ogievskiy
1. BDRV_REQ_NO_SERIALISING doesn't exist already, don't mention it. 2. We are going to add one more user of BDRV_REQ_SERIALISING, so comment about backup becomes a bit confusing here. The use case in backup is documented in block/backup.c, so let's just drop duplication here. 3. The fact that BDRV_REQ_SERIALISING is only for write requests is omitted. Add a note. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20201021145859.11201-2-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-12-11block: introduce BDRV_MAX_LENGTHVladimir Sementsov-Ogievskiy
We are going to modify block layer to work with 64bit requests. And first step is moving to int64_t type for both offset and bytes arguments in all block request related functions. It's mostly safe (when widening signed or unsigned int to int64_t), but switching from uint64_t is questionable. So, let's first establish the set of requests we want to work with. First signed int64_t should be enough, as off_t is signed anyway. Then, obviously offset + bytes should not overflow. And most interesting: (offset + bytes) being aligned up should not overflow as well. Aligned to what alignment? First thing that comes in mind is bs->bl.request_alignment, as we align up request to this alignment. But there is another thing: look at bdrv_mark_request_serialising(). It aligns request up to some given alignment. And this parameter may be bdrv_get_cluster_size(), which is often a lot greater than bs->bl.request_alignment. Note also, that bdrv_mark_request_serialising() uses signed int64_t for calculations. So, actually, we already depend on some restrictions. Happily, bdrv_get_cluster_size() returns int and bs->bl.request_alignment has 32bit unsigned type, but defined to be a power of 2 less than INT_MAX. So, we may establish, that INT_MAX is absolute maximum for any kind of alignment that may occur with the request. Note, that bdrv_get_cluster_size() is not documented to return power of 2, still bdrv_mark_request_serialising() behaves like it is. Also, backup uses bdi.cluster_size and is not prepared to it not being power of 2. So, let's establish that Qemu supports only power-of-2 clusters and alignments. So, alignment can't be greater than 2^30. Finally to be safe with calculations, to not calculate different maximums for different nodes (depending on cluster size and request_alignment), let's simply set QEMU_ALIGN_DOWN(INT64_MAX, 2^30) as absolute maximum bytes length for Qemu. Actually, it's not much less than INT64_MAX. OK, then, let's apply it to block/io. Let's consider all block/io entry points of offset/bytes: 4 bytes/offset interface functions: bdrv_co_preadv_part(), bdrv_co_pwritev_part(), bdrv_co_copy_range_internal() and bdrv_co_pdiscard() and we check them all with bdrv_check_request(). We also have one entry point with only offset: bdrv_co_truncate(). Check the offset. And one public structure: BdrvTrackedRequest. Happily, it has only three external users: file-posix.c: adopted by this patch write-threshold.c: only read fields test-write-threshold.c: sets obviously small constant values Better is to make the structure private and add corresponding interfaces.. Still it's not obvious what kind of interface is needed for file-posix.c. Let's keep it public but add corresponding assertions. After this patch we'll convert functions in block/io.c to int64_t bytes and offset parameters. We can assume that offset/bytes pair always satisfy new restrictions, and make corresponding assertions where needed. If we reach some offset/bytes point in block/io.c missing bdrv_check_request() it is considered a bug. As well, if block/io.c modifies a offset/bytes request, expanding it more then aligning up to request_alignment, it's a bug too. For all io requests except for discard we keep for now old restriction of 32bit request length. iotest 206 output error message changed, as now test disk size is larger than new limit. Add one more test case with new maximum disk size to cover too-big-L1 case. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20201203222713.13507-5-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-11-09block: Move bdrv_drain_all_end_quiesce() to block_int.hGreg Kurz
This function is really an internal helper for bdrv_close(). Update its doc comment to make this clear and make the function private. Signed-off-by: Greg Kurz <groug@kaod.org> Message-Id: <160387245480.131299.13430357162209598411.stgit@bahia> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-10-27block: End quiescent sections when a BDS is deletedGreg Kurz
If a BDS gets deleted during blk_drain_all(), it might miss a call to bdrv_do_drained_end(). This means missing a call to aio_enable_external() and the AIO context remains disabled for ever. This can cause a device to become irresponsive and to disrupt the guest execution, ie. hang, loop forever or worse. This scenario is quite easy to encounter with virtio-scsi on POWER when punching multiple blockdev-create QMP commands while the guest is booting and it is still running the SLOF firmware. This happens because SLOF disables/re-enables PCI devices multiple times via IO/MEM/MASTER bits of PCI_COMMAND register after the initial probe/feature negotiation, as it tends to work with a single device at a time at various stages like probing and running block/network bootloaders without doing a full reset in-between. This naturally generates many dataplane stops and starts, and thus many drain sections that can race with blockdev_create_run(). In the end, SLOF bails out. It is somehow reproducible on x86 but it requires to generate articial dataplane start/stop activity with stop/cont QMP commands. In this case, seabios ends up looping for ever, waiting for the virtio-scsi device to send a response to a command it never received. Add a helper that pairs all previously called bdrv_do_drained_begin() with a bdrv_do_drained_end() and call it from bdrv_close(). While at it, update the "/bdrv-drain/graph-change/drain_all" test in test-bdrv-drain so that it can catch the issue. BugId: https://bugzilla.redhat.com/show_bug.cgi?id=1874441 Signed-off-by: Greg Kurz <groug@kaod.org> Message-Id: <160346526998.272601.9045392804399803158.stgit@bahia.lan> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-27qcow2: Skip copy-on-write when allocating a zero clusterAlberto Garcia
Since commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a when a write request results in a new allocation QEMU first tries to see if the rest of the cluster outside the written area contains only zeroes. In that case, instead of doing a normal copy-on-write operation and writing explicit zero buffers to disk, the code zeroes the whole cluster efficiently using pwrite_zeroes() with BDRV_REQ_NO_FALLBACK. This improves performance very significantly but it only happens when we are writing to an area that was completely unallocated before. Zero clusters (QCOW2_CLUSTER_ZERO_*) are treated like normal clusters and are therefore slower to allocate. This happens because the code uses bdrv_is_allocated_above() rather bdrv_block_status_above(). The former is not as accurate for this purpose but it is faster. However in the case of qcow2 the underlying call does already report zero clusters just fine so there is no reason why we cannot use that information. After testing 4KB writes on an image that only contains zero clusters this patch results in almost five times more IOPS. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <6d77cab968c501c44d6e1089b9bc91b04170b49e.1603731354.git.berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-09block: Add bdrv_lock()/unlock()Kevin Wolf
Inside of coroutine context, we can't directly use aio_context_acquire() for the AioContext of a block node because we already own the lock of the current AioContext and we need to avoid double locking to prevent deadlocks. This provides helper functions to lock the AioContext of a node only if it's not the same as the current AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20201005155855.256490-14-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09block: Add bdrv_co_enter()/leave()Kevin Wolf
Add a pair of functions to temporarily move the current coroutine to the AioContext of a given BlockDriverState. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20201005155855.256490-13-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-05include/block/block.h: drop non-ascii quotation markVladimir Sementsov-Ogievskiy
This is the only non-ascii character in the file and it doesn't really needed here. Let's use normal "'" symbol for consistency with the rest 11 occurrences of "'" in the file. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-05block/io: refactor save/load vmstateVladimir Sementsov-Ogievskiy
Like for read/write in a previous commit, drop extra indirection layer, generate directly bdrv_readv_vmstate() and bdrv_writev_vmstate(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-8-vsementsov@virtuozzo.com>
2020-10-05block: drop bdrv_prwvVladimir Sementsov-Ogievskiy
Now that we are not maintaining boilerplate code for coroutine wrappers, there is no more sense in keeping the extra indirection layer of bdrv_prwv(). Let's drop it and instead generate pure bdrv_preadv() and bdrv_pwritev(). Currently, bdrv_pwritev() and bdrv_preadv() are returning bytes on success, auto generated functions will instead return zero, as their _co_ prototype. Still, it's simple to make the conversion safe: the only external user of bdrv_pwritev() is test-bdrv-drain, and it is comfortable enough with bdrv_co_pwritev() instead. So prototypes are moved to local block/coroutines.h. Next, the only internal use is bdrv_pread() and bdrv_pwrite(), which are modified to return bytes on success. Of course, it would be great to convert bdrv_pread() and bdrv_pwrite() to return 0 on success. But this requires audit (and probably conversion) of all their users, let's leave it for another day refactoring. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-7-vsementsov@virtuozzo.com>
2020-10-05block: generate coroutine-wrapper codeVladimir Sementsov-Ogievskiy
Use code generation implemented in previous commit to generated coroutine wrappers in block.c and block/io.c Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-6-vsementsov@virtuozzo.com>
2020-10-05scripts: add block-coroutine-wrapper.pyVladimir Sementsov-Ogievskiy
We have a very frequent pattern of creating a coroutine from a function with several arguments: - create a structure to pack parameters - create _entry function to call original function taking parameters from struct - do different magic to handle completion: set ret to NOT_DONE or EINPROGRESS or use separate bool field - fill the struct and create coroutine from _entry function with this struct as a parameter - do coroutine enter and BDRV_POLL_WHILE loop Let's reduce code duplication by generating coroutine wrappers. This patch adds scripts/block-coroutine-wrapper.py together with some friends, which will generate functions with declared prototypes marked by the 'generated_co_wrapper' specifier. The usage of new code generation is as follows: 1. define the coroutine function somewhere int coroutine_fn bdrv_co_NAME(...) {...} 2. declare in some header file int generated_co_wrapper bdrv_NAME(...); with same list of parameters (generated_co_wrapper is defined in "include/block/block.h"). 3. Make sure the block_gen_c declaration in block/meson.build mentions the file with your marker function. Still, no function is now marked, this work is for the following commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200924185414.28642-5-vsementsov@virtuozzo.com> [Added encoding='utf-8' to open() calls as requested by Vladimir. Fixed typo and grammar issues pointed out by Eric Blake. Removed clang-format dependency that caused build test issues. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-05block: return error-code from bdrv_invalidate_cacheVladimir Sementsov-Ogievskiy
This is the only coroutine wrapper from block.c and block/io.c which doesn't return a value, so let's convert it to the common behavior, to simplify moving to generated coroutine wrappers in a further commit. Also, bdrv_invalidate_cache is a void function, returning error only through **errp parameter, which is considered to be bad practice, as it forces callers to define and propagate local_err variable, so conversion is good anyway. This patch leaves the conversion of .bdrv_co_invalidate_cache() driver callbacks and bdrv_invalidate_cache_all() for another day. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200924185414.28642-2-vsementsov@virtuozzo.com>
2020-09-07block: Add bdrv_supports_compressed_writes()Max Reitz
Filters cannot compress data themselves but they have to implement .bdrv_co_pwritev_compressed() still (or they cannot forward compressed writes). Therefore, checking whether bs->drv->bdrv_co_pwritev_compressed is non-NULL is not sufficient to know whether the node can actually handle compressed writes. This function looks down the filter chain to see whether there is a non-filter that can actually convert the compressed writes into compressed data (and thus normal writes). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07block: Drop bdrv_is_encrypted()Max Reitz
The original purpose of bdrv_is_encrypted() was to inquire whether a BDS can be used without the user entering a password or not. It has not been used for that purpose for quite some time. Actually, it is not even fit for that purpose, because to answer that question, it would have recursively query all of the given node's children. So now we have to decide in which direction we want to fix bdrv_is_encrypted(): Recursively query all children, or drop it and just use bs->encrypted to get the current node's status? Nowadays, its only purpose is to report through bdrv_query_image_info() whether the given image is encrypted or not. For this purpose, it is probably more interesting to see whether a given node itself is encrypted or not (otherwise, a management application cannot discern for certain which nodes are really encrypted and which just have encrypted children). Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14block: Add support to warn on backing file change without formatEric Blake
For now, this is a mechanical addition; all callers pass false. But the next patch will use it to improve 'qemu-img rebase -u' when selecting a backing file with no format. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com> Message-Id: <20200706203954.341758-10-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-06block: drop unallocated_blocks_are_zeroVladimir Sementsov-Ogievskiy
Currently this field only set by qed and qcow2. But in fact, all backing-supporting formats (parallels, qcow, qcow2, qed, vmdk) share these semantics: on unallocated blocks, if there is no backing file they just memset the buffer with zeroes. So, document this behavior for .supports_backing and drop .unallocated_blocks_are_zero Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200528094405.145708-10-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06block: inline bdrv_unallocated_blocks_are_zero()Vladimir Sementsov-Ogievskiy
The function has only one user: bdrv_co_block_status(). Inline it to simplify reviewing of the following patches, which will finally drop unallocated_blocks_are_zero field too. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@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>
2020-06-26osdep: Make MIN/MAX evaluate arguments only onceEric Blake
I'm not aware of any immediate bugs in qemu where a second runtime evaluation of the arguments to MIN() or MAX() causes a problem, but proactively preventing such abuse is easier than falling prey to an unintended case down the road. At any rate, here's the conversation that sparked the current patch: https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg05718.html Update the MIN/MAX macros to only evaluate their argument once at runtime; this uses typeof(1 ? (a) : (b)) to ensure that we are promoting the temporaries to the same type as the final comparison (we have to trigger type promotion, as typeof(bitfield) won't compile; and we can't use typeof((a) + (b)) or even typeof((a) + 0), as some of our uses of MAX are on void* pointers where such addition is undefined). However, we are unable to work around gcc refusing to compile ({}) in a constant context (such as the array length of a static variable), even when only used in the dead branch of a __builtin_choose_expr(), so we have to provide a second macro pair MIN_CONST and MAX_CONST for use when both arguments are known to be compile-time constants and where the result must also be usable as a constant; this second form evaluates arguments multiple times but that doesn't matter for constants. By using a void expression as the expansion if a non-constant is presented to this second form, we can enlist the compiler to ensure the double evaluation is not attempted on non-constants. Alas, as both macros now rely on compiler intrinsics, they are no longer usable in preprocessor #if conditions; those will just have to be open-coded or the logic rewritten into #define or runtime 'if' conditions (but where the compiler dead-code-elimination will probably still apply). I tested that both gcc 10.1.1 and clang 10.0.0 produce errors for all forms of macro mis-use. As the errors can sometimes be cryptic, I'm demonstrating the gcc output: Use of MIN when MIN_CONST is needed: In file included from /home/eblake/qemu/qemu-img.c:25: /home/eblake/qemu/include/qemu/osdep.h:249:5: error: braced-group within expression allowed only inside a function 249 | ({ \ | ^ /home/eblake/qemu/qemu-img.c:92:12: note: in expansion of macro ‘MIN’ 92 | char array[MIN(1, 2)] = ""; | ^~~ Use of MIN_CONST when MIN is needed: /home/eblake/qemu/qemu-img.c: In function ‘is_allocated_sectors’: /home/eblake/qemu/qemu-img.c:1225:15: error: void value not ignored as it ought to be 1225 | i = MIN_CONST(i, n); | ^ Use of MIN in the preprocessor: In file included from /home/eblake/qemu/accel/tcg/translate-all.c:20: /home/eblake/qemu/accel/tcg/translate-all.c: In function ‘page_check_range’: /home/eblake/qemu/include/qemu/osdep.h:249:6: error: token "{" is not valid in preprocessor expressions 249 | ({ \ | ^ Fix the resulting callsites that used #if or computed a compile-time constant min or max to use the new macros. cpu-defs.h is interesting, as CPU_TLB_DYN_MAX_BITS is sometimes used as a constant and sometimes dynamic. It may be worth improving glib's MIN/MAX definitions to be saner, but that is a task for another day. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200625162602.700741-1-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@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>
2020-05-18block: Add bdrv_make_empty()Max Reitz
Right now, all users of bdrv_make_empty() call the BlockDriver method directly. That is not only bad style, it is also wrong, unless the caller has a BdrvChild with a WRITE or WRITE_UNCHANGED permission. (WRITE_UNCHANGED suffices, because callers generally use this function to clear a node with a backing file after a commit operation.) Introduce bdrv_make_empty() that verifies that it does. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200429141126.85159-2-mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08block: Drop unused .bdrv_has_zero_init_truncateEric Blake
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>
2020-04-30block: Add flags to bdrv(_co)_truncate()Kevin Wolf
Now that block drivers can support flags for .bdrv_co_truncate, expose the parameter in the node level interfaces bdrv_co_truncate() and bdrv_truncate(). Signed-off-by: Kevin Wolf <kwolf@redhat.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: <20200424125448.63318-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-26block: trickle down the fallback image creation function use to the block ↵Maxim Levitsky
drivers Instead of checking the .bdrv_co_create_opts to see if we need the fallback, just implement the .bdrv_co_create_opts in the drivers that need it. This way we don't break various places that need to know if the underlying protocol/format really supports image creation, and this way we still allow some drivers to not support image creation. Fixes: fd17146cd93d1704cd96d7c2757b325fc7aac6fd Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1816007 Note that technically this driver reverts the image creation fallback for the vxhs driver since I don't have a means to test it, and IMHO it is better to leave it not supported as it was prior to generic image creation patches. Also drop iscsi_create_opts which was left accidentally. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-3-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> [mreitz: Fixed alignment, and moved bdrv_co_create_opts_simple() and bdrv_create_opts_simple from block.h into block_int.h] Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-11block.c: adding bdrv_co_delete_fileDaniel Henrique Barboza
Using the new 'bdrv_co_delete_file' interface, a pure co_routine function 'bdrv_co_delete_file' inside block.c can can be used in a way similar of the existing bdrv_create_file to to clean up a created file. We're creating a pure co_routine because the only caller of 'bdrv_co_delete_file' will be already in co_routine context, thus there is no need to add all the machinery to check for qemu_in_coroutine() and create a separated co_routine to do the job. Suggested-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Message-Id: <20200130213907.2830642-3-danielhb413@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-20qapi: Allow getting flat output from 'query-named-block-nodes'Peter Krempa
When a management application manages node names there's no reason to recurse into backing images in the output of query-named-block-nodes. Add a parameter to the command which will return just the top level structs. Signed-off-by: Peter Krempa <pkrempa@redhat.com> Message-Id: <4470f8c779abc404dcf65e375db195cd91a80651.1579509782.git.pkrempa@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> [mreitz: Fixed coding style] Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-18block: Remove bdrv_recurse_is_first_non_filter()Max Reitz
It no longer has any users. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200218103454.296704-11-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-02-18block: Drop bdrv_is_first_non_filter()Max Reitz
It is unused now. (And it was ugly because it needed to explore all BDS chains from the top.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200218103454.296704-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-01-30blockdev: adds bdrv_parse_aio to use io_uringAarushi Mehta
Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20200120141858.587874-8-stefanha@redhat.com Message-Id: <20200120141858.587874-8-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30block/block: add BDRV flag for io_uringAarushi Mehta
Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com> Reviewed-by: Maxim Levitsky <maximlevitsky@gmail.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20200120141858.587874-4-stefanha@redhat.com Message-Id: <20200120141858.587874-4-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30block: eliminate BDRV_REQ_NO_SERIALISINGPaolo Bonzini
It is unused since commit 00e30f0 ("block/backup: use backup-top instead of write notifiers", 2019-10-01), drop it to simplify the code. While at it, drop redundant assertions on flags. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1578495356-46219-2-git-send-email-pbonzini@redhat.com Message-Id: <1578495356-46219-2-git-send-email-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-06block: Add bdrv_qapi_perm_to_blk_perm()Max Reitz
We need some way to correlate QAPI BlockPermission values with BLK_PERM_* flags. We could: (1) have the same order in the QAPI definition as the the BLK_PERM_* flags are in LSb-first order. However, then there is no guarantee that they actually match (e.g. when someone modifies the QAPI schema without thinking of the BLK_PERM_* definitions). We could add static assertions, but these would break what’s good about this solution, namely its simplicity. (2) define the BLK_PERM_* flags based on the BlockPermission values. But this way whenever someone were to modify the QAPI order (perfectly sensible in theory), the BLK_PERM_* values would change. Because these values are used for file locking, this might break file locking between different qemu versions. Therefore, go the slightly more cumbersome way: Add a function to translate from the QAPI constants to the BLK_PERM_* flags. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20191108123455.39445-2-mreitz@redhat.com Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28block: Add @exact parameter to bdrv_co_truncate()Max Reitz
We have two drivers (iscsi and file-posix) that (in some cases) return success from their .bdrv_co_truncate() implementation if the block device is larger than the requested offset, but cannot be shrunk. Some callers do not want that behavior, so this patch adds a new parameter that they can use to turn off that behavior. This patch just adds the parameter and lets the block/io.c and block/block-backend.c functions pass it around. All other callers always pass false and none of the implementations evaluate it, so that this patch does not change existing behavior. Future patches take care of that. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-5-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-17block: switch reopen queue from QSIMPLEQ to QTAILQVladimir Sementsov-Ogievskiy
We'll need reverse-foreach in the following commit, QTAILQ support it, so move to QTAILQ. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20190927122355.7344-2-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-10qapi: query-blockstat: add driver specific file-posix statsAnton Nefedov
A block driver can provide a callback to report driver-specific statistics. file-posix driver now reports discard statistics Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Markus Armbruster <armbru@redhat.com> Message-id: 20190923121737.83281-10-anton.nefedov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-16block: Remove unused masksNir Soffer
Replace confusing usage: ~BDRV_SECTOR_MASK With more clear: (BDRV_SECTOR_SIZE - 1) Remove BDRV_SECTOR_MASK and the unused BDRV_BLOCK_OFFSET_MASK which was it's last user. Signed-off-by: Nir Soffer <nsoffer@redhat.com> Message-id: 20190827185913.27427-3-nsoffer@redhat.com Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19block: Add bdrv_has_zero_init_truncate()Max Reitz
No .bdrv_has_zero_init() implementation returns 1 if growing the file would add non-zero areas (at least with PREALLOC_MODE_OFF), so using it in lieu of this new function was always safe. But on the other hand, it is possible that growing an image that is not zero-initialized would still add a zero-initialized area, like when using nonpreallocating truncation on a preallocated image. For callers that care only about truncation, not about creation with potential preallocation, this new function is useful. Alternatively, we could have added a PreallocMode parameter to bdrv_has_zero_init(). But the only user would have been qemu-img convert, which does not have a plain PreallocMode value right now -- it would have to parse the creation option to obtain it. Therefore, the simpler solution is to let bdrv_has_zero_init() inquire the preallocation status and add the new bdrv_has_zero_init_truncate() that presupposes PREALLOC_MODE_OFF. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-4-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-16Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-08-15' into ↵Peter Maydell
staging nbd patches for 2019-08-15 - Addition of InetSocketAddress keep-alive - Addition of BDRV_REQ_PREFETCH for more efficient copy-on-read - Initial refactoring in preparation of NBD reconnect # gpg: Signature made Thu 15 Aug 2019 19:28:41 BST # gpg: using RSA key A7A16B4A2527436A # 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-2019-08-15: block/nbd: refactor nbd connection parameters block/nbd: add cmdline and qapi parameter reconnect-delay block/nbd: move from quit to state block/nbd: use non-blocking io channel for nbd negotiation block/nbd: split connection_co start out of nbd_client_connect nbd: improve CMD_CACHE: use BDRV_REQ_PREFETCH block/stream: use BDRV_REQ_PREFETCH block: implement BDRV_REQ_PREFETCH qapi: Add InetSocketAddress member keep-alive Signed-off-by: Peter Maydell <peter.maydell@linaro.org>