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2024-03-12block/copy-before-write: Fix missing ERRP_GUARD() for error_prepend()Zhao Liu
As the comment in qapi/error, passing @errp to error_prepend() requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: ... * - It should not be passed to error_prepend(), error_vprepend() or * error_append_hint(), because that doesn't work with &error_fatal. * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. ERRP_GUARD() could avoid the case when @errp is &error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. The cbw_open() passes @errp to error_prepend() without ERRP_GUARD(). Though it is the BlockDriver.bdrv_open() method, and currently its @errp parameter only points to callers' local_err, to follow the requirement of @errp, add missing ERRP_GUARD() at the beginning of this function. [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: John Snow <jsnow@redhat.com> Cc: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Hanna Reitz <hreitz@redhat.com> Cc: qemu-block@nongnu.org Signed-off-by: Zhao Liu <zhao1.liu@intel.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-ID: <20240311033822.3142585-5-zhao1.liu@linux.intel.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-12-21block: remove AioContext lockingStefan Hajnoczi
This is the big patch that removes aio_context_acquire()/aio_context_release() from the block layer and affected block layer users. There isn't a clean way to split this patch and the reviewers are likely the same group of people, so I decided to do it in one patch. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Paul Durrant <paul@xen.org> Message-ID: <20231205182011.1976568-7-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-08block: Protect bs->file with graph_lockKevin Wolf
Almost all functions that access bs->file already take the graph lock now. Add locking to the remaining users and finally annotate the struct field itself as protected by the graph lock. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20231027155333.420094-25-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-08block: Take graph lock for most of .bdrv_openKevin Wolf
Most implementations of .bdrv_open first open their file child (which is an operation that internally takes the write lock and therefore we shouldn't hold the graph lock while calling it), and afterwards many operations that require holding the graph lock, e.g. for accessing bs->file. This changes block drivers that follow this pattern to take the graph lock after opening the child node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20231027155333.420094-24-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-08block: Add missing GRAPH_RDLOCK annotationsKevin Wolf
This adds GRAPH_RDLOCK to some driver callbacks that are already called with the graph lock held, and which will need the annotation because they access bs->file, but don't have it yet. This also covers a few callbacks that were not marked GRAPH_RDLOCK before, but where updating BlockDriver is trivially possible. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20231027155333.420094-21-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12block: convert more bdrv_is_allocated* and bdrv_block_status* calls to ↵Paolo Bonzini
coroutine versions Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20230904100306.156197-5-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-09-20block: Mark bdrv_child_perm() GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_child_perm() need to hold a reader lock for the graph because some implementations access the children list of a node. The callers of bdrv_child_perm() conveniently already hold the lock. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20230911094620.45040-16-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-09-08block: Make more BlockDriver definitions staticKevin Wolf
Most block driver implementations don't have any reason for their BlockDriver to be public. The only exceptions are bdrv_file, bdrv_raw and bdrv_qcow2, which are actually used in other source files. Make all other BlockDriver definitions static if they aren't yet. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230905130607.35134-3-kwolf@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30copy-before-write: Fix open with child in iothreadKevin Wolf
The AioContext lock must not be held for bdrv_open_child(), but it is necessary for the following operations, in particular those using nested event loops in coroutine wrappers. Temporarily dropping the main AioContext lock is not necessary because we know we run in the main thread. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-9-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark preadv_snapshot/snapshot_block_status GRAPH_RDLOCKKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-16-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark public read/write functions GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph. For some places, we know that they will hold the lock, but we don't have the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock() with a FIXME comment. These places will be removed once everything is properly annotated. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-12-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph. For some places, we know that they will hold the lock, but we don't have the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock() with a FIXME comment. These places will be removed once everything is properly annotated. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-10-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCKEmanuele Giuseppe Esposito
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_pdiscard() need to hold a reader lock for the graph. For some places, we know that they will hold the lock, but we don't have the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock() with a FIXME comment. These places will be removed once everything is properly annotated. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-9-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_flush() and callers GRAPH_RDLOCKEmanuele Giuseppe Esposito
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_flush() need to hold a reader lock for the graph. For some places, we know that they will hold the lock, but we don't have the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock() with a FIXME comment. These places will be removed once everything is properly annotated. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-8-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-01-20include/block: Untangle inclusion loopsMarkus Armbruster
We have two inclusion loops: block/block.h -> block/block-global-state.h -> block/block-common.h -> block/blockjob.h -> block/block.h block/block.h -> block/block-io.h -> block/block-common.h -> block/blockjob.h -> block/block.h I believe these go back to Emanuele's reorganization of the block API, merged a few months ago in commit d7e2fe4aac8. Fortunately, breaking them is merely a matter of deleting unnecessary includes from headers, and adding them back in places where they are now missing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2022-12-15Merge tag 'pull-misc-2022-12-14' of https://repo.or.cz/qemu/armbru into stagingPeter Maydell
Miscellaneous patches for 2022-12-14 # gpg: Signature made Wed 14 Dec 2022 15:23:02 GMT # gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653 # gpg: issuer "armbru@redhat.com" # gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full] # gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full] # Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653 * tag 'pull-misc-2022-12-14' of https://repo.or.cz/qemu/armbru: ppc4xx_sdram: Simplify sdram_ddr_size() to return block/vmdk: Simplify vmdk_co_create() to return directly cleanup: Tweak and re-run return_directly.cocci io: Tidy up fat-fingered parameter name qapi: Use returned bool to check for failure (again) sockets: Use ERRP_GUARD() where obviously appropriate qemu-config: Use ERRP_GUARD() where obviously appropriate qemu-config: Make config_parse_qdict() return bool monitor: Use ERRP_GUARD() in monitor_init() monitor: Simplify monitor_fd_param()'s error handling error: Move ERRP_GUARD() to the beginning of the function error: Drop a few superfluous ERRP_GUARD() error: Drop some obviously superfluous error_propagate() Drop more useless casts from void * to pointer Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-12-14qapi block: Elide redundant has_FOO in generated CMarkus Armbruster
The has_FOO for pointer-valued FOO are redundant, except for arrays. They are also a nuisance to work with. Recent commit "qapi: Start to elide redundant has_FOO in generated C" provided the means to elide them step by step. This is the step for qapi/block*.json. Said commit explains the transformation in more detail. There is one instance of the invariant violation mentioned there: qcow2_signal_corruption() passes false, "" when node_name is an empty string. Take care to pass NULL then. The previous two commits cleaned up two more. Additionally, helper bdrv_latency_histogram_stats() loses its output parameters and returns a value instead. Cc: Kevin Wolf <kwolf@redhat.com> Cc: Hanna Reitz <hreitz@redhat.com> Cc: qemu-block@nongnu.org Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221104160712.3005652-11-armbru@redhat.com> [Fixes for #ifndef LIBRBD_SUPPORTS_ENCRYPTION and MacOS squashed in]
2022-12-14error: Drop a few superfluous ERRP_GUARD()Markus Armbruster
include/qapi/error.h on ERRP_GUARD(): * It must be used when the function dereferences @errp or passes * @errp to error_prepend(), error_vprepend(), or error_append_hint(). * It is safe to use even when it's not needed, but please avoid * cluttering the source with useless code. Clean up some of this clutter. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221121085054.683122-3-armbru@redhat.com>
2022-10-27block: introduce bdrv_open_file_child() helperVladimir Sementsov-Ogievskiy
Almost all drivers call bdrv_open_child() similarly. Let's create a helper for this. The only not updated drivers that call bdrv_open_child() to set bs->file are raw-format and snapshot-access: raw-format sometimes want to have filtered child but don't set drv->is_filter to true. snapshot-access wants only DATA | PRIMARY Possibly we should implement drv->is_filter_func() handler, to consider raw-format as filter when it works as filter.. But it's another story. Note also, that we decrease assignments to bs->file in code: it helps us restrict modifying this field in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220726201134.924743-3-vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07copy-before-write: add missing coroutine_fn annotationsPaolo Bonzini
Callers of coroutine_fn must be coroutine_fn themselves, or the call must be within "if (qemu_in_coroutine())". Apply coroutine_fn to functions where this holds. Reviewed-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220922084924.201610-16-pbonzini@redhat.com> [kwolf: Fixed up coding style] Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-29block/copy-before-write: implement cbw-timeout optionVladimir Sementsov-Ogievskiy
In some scenarios, when copy-before-write operations lasts too long time, it's better to cancel it. Most useful would be to use the new option together with on-cbw-error=break-snapshot: this way if cbw operation takes too long time we'll just cancel backup process but do not disturb the guest too much. Note the tricky point of realization: we keep additional point in bs->in_flight during block_copy operation even if it's timed-out. Background "cancelled" block_copy operations will finish at some point and will want to access state. We should care to not free the state in .bdrv_close() earlier. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> [vsementsov: use bdrv_inc_in_flight()/bdrv_dec_in_flight() instead of direct manipulation on bs->in_flight] Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2022-06-29block/block-copy: block_copy(): add timeout_ns parameterVladimir Sementsov-Ogievskiy
Add possibility to limit block_copy() call in time. To be used in the next commit. As timed-out block_copy() call will continue in background anyway (we can't immediately cancel IO operation), it's important also give user a possibility to pass a callback, to do some additional actions on block-copy call finish. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2022-06-28block/copy-before-write: add on-cbw-error open parameterVladimir Sementsov-Ogievskiy
Currently, behavior on copy-before-write operation failure is simple: report error to the guest. Let's implement alternative behavior: break the whole copy-before-write process (and corresponding backup job or NBD client) but keep guest working. It's needed if we consider guest stability as more important. The realisation is simple: on copy-before-write failure we set s->snapshot_ret and continue guest operations. s->snapshot_ret being set will lead to all further snapshot API requests. Note that all in-flight snapshot-API requests may still success: we do wait for them on BREAK_SNAPSHOT-failure path in cbw_do_copy_before_write(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2022-06-28block/copy-before-write: refactor option parsingVladimir Sementsov-Ogievskiy
We are going to add one more option of enum type. Let's refactor option parsing so that we can simply work with BlockdevOptionsCbw object. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
2022-03-07block: copy-before-write: realize snapshot-access APIVladimir Sementsov-Ogievskiy
Current scheme of image fleecing looks like this: [guest] [NBD export] | | |root | root v v [copy-before-write] -----> [temp.qcow2] | target | |file |backing v | [active disk] <-------------+ - On guest writes copy-before-write filter copies old data from active disk to temp.qcow2. So fleecing client (NBD export) when reads changed regions from temp.qcow2 image and unchanged from active disk through backing link. This patch makes possible new image fleecing scheme: [guest] [NBD export] | | | root | root v file v [copy-before-write]<------[snapshot-access] | | | file | target v v [active-disk] [temp.img] - copy-before-write does CBW operations and also provides snapshot-access API. The API may be accessed through snapshot-access driver. Benefits of new scheme: 1. Access control: if remote client try to read data that not covered by original dirty bitmap used on copy-before-write open, client gets -EACCES. 2. Discard support: if remote client do DISCARD, this additionally to discarding data in temp.img informs block-copy process to not copy these clusters. Next read from discarded area will return -EACCES. This is significant thing: when fleecing user reads data that was not yet copied to temp.img, we can avoid copying it on further guest write. 3. Synchronisation between client reads and block-copy write is more efficient. In old scheme we just rely on BDRV_REQ_SERIALISING flag used for writes to temp.qcow2. New scheme is less blocking: - fleecing reads are never blocked: if data region is untouched or in-flight, we just read from active-disk, otherwise we read from temp.img - writes to temp.img are not blocked by fleecing reads - still, guest writes of-course are blocked by in-flight fleecing reads, that currently read from active-disk - it's the minimum necessary blocking 4. Temporary image may be of any format, as we don't rely on backing feature. 5. Permission relation are simplified. With old scheme we have to share write permission on target child of copy-before-write, otherwise backing link conflicts with copy-before-write file child write permissions. With new scheme we don't have backing link, and copy-before-write node may have unshared access to temporary node. (Not realized in this commit, will be in future). 6. Having control on fleecing reads we'll be able to implement alternative behavior on failed copy-before-write operations. Currently we just break guest request (that's a historical behavior of backup). But in some scenarios it's a bad behavior: better is to drop the backup as failed but don't break guest request. With new scheme we can simply unset some bits in a bitmap on CBW failure and further fleecing reads will -EACCES, or something like this. (Not implemented in this commit, will be in future) Additional application for this is implementing timeout for CBW operations. Iotest 257 output is updated, as two more bitmaps now live in copy-before-write filter. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20220303194349.2304213-13-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07block/copy-before-write: add bitmap open parameterVladimir Sementsov-Ogievskiy
This brings "incremental" mode to copy-before-write filter: user can specify bitmap so that filter will copy only "dirty" areas. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20220303194349.2304213-5-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07block/block-copy: block_copy_state_new(): add bitmap parameterVladimir Sementsov-Ogievskiy
This will be used in the following commit to bring "incremental" mode to copy-before-write filter. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220303194349.2304213-4-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07block/block-copy: move copy_bitmap initialization to block_copy_state_new()Vladimir Sementsov-Ogievskiy
We are going to complicate bitmap initialization in the further commit. And in future, backup job will be able to work without filter (when source is immutable), so we'll need same bitmap initialization in copy-before-write filter and in backup job. So, it's reasonable to do it in block-copy. Note that for now cbw_open() is the only caller of block_copy_state_new(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220303194349.2304213-2-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-04block/copy-before-write.h: global state API + assertionsEmanuele Giuseppe Esposito
copy-before-write functions always run under BQL. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220303151616.325444-24-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-09-29block: use int64_t instead of int in driver discard handlersVladimir 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 driver discard handlers bytes parameter to int64_t. The only caller of all updated function is bdrv_co_pdiscard in block/io.c. It is already prepared to work with 64bit requests, but pass at most max(bs->bl.max_pdiscard, INT_MAX) to the driver. Let's look at all updated functions: blkdebug: all calculations are still OK, thanks to bdrv_check_qiov_request(). both rule_check and bdrv_co_pdiscard are 64bit blklogwrites: pass to blk_loc_writes_co_log which is 64bit blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pdiscard, OK copy-before-write: pass to bdrv_co_pdiscard which is 64bit and to cbw_do_copy_before_write which is 64bit file-posix: one handler calls raw_account_discard() is 64bit and both handlers calls raw_do_pdiscard(). Update raw_do_pdiscard, which pass to RawPosixAIOData::aio_nbytes, which is 64bit (and calls raw_account_discard()) gluster: somehow, third argument of glfs_discard_async is size_t. Let's set max_pdiscard accordingly. iscsi: iscsi_allocmap_set_invalid is 64bit, !is_byte_request_lun_aligned is 64bit. list.num is uint32_t. Let's clarify max_pdiscard and pdiscard_alignment. mirror_top: pass to bdrv_mirror_top_do_write() which is 64bit nbd: protocol limitation. max_pdiscard is alredy set strict enough, keep it as is for now. nvme: buf.nlb is uint32_t and we do shift. So, add corresponding limits to nvme_refresh_limits(). preallocate: pass to bdrv_co_pdiscard() which is 64bit. rbd: pass to qemu_rbd_start_co() which is 64bit. qcow2: calculations are still OK, thanks to bdrv_check_qiov_request(), qcow2_cluster_discard() is 64bit. raw-format: raw_adjust_offset() is 64bit, bdrv_co_pdiscard too. throttle: pass to bdrv_co_pdiscard() which is 64bit and to throttle_group_co_io_limits_intercept() which is 64bit as well. test-block-iothread: bytes argument is unused Great! Now all drivers are prepared to handle 64bit discard requests, or else have explicit max_pdiscard limits. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-11-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29block: use int64_t instead of int in driver write_zeroes handlersVladimir 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 driver write_zeroes handlers bytes parameter to int64_t. The only caller of all updated function is bdrv_co_do_pwrite_zeroes(). bdrv_co_do_pwrite_zeroes() itself is of course OK with widening of callee parameter type. Also, bdrv_co_do_pwrite_zeroes()'s max_write_zeroes is limited to INT_MAX. So, updated functions all are safe, they will not get "bytes" larger than before. Still, let's look through all updated functions, and add assertions to the ones which are actually unprepared to values larger than INT_MAX. For these drivers also set explicit max_pwrite_zeroes limit. Let's go: blkdebug: calculations can't overflow, thanks to bdrv_check_qiov_request() in generic layer. rule_check() and bdrv_co_pwrite_zeroes() both have 64bit argument. blklogwrites: pass to blk_log_writes_co_log() with 64bit argument. blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pwrite_zeroes() which is OK copy-before-write: Calls cbw_do_copy_before_write() and bdrv_co_pwrite_zeroes, both have 64bit argument. file-posix: both handler calls raw_do_pwrite_zeroes, which is updated. In raw_do_pwrite_zeroes() calculations are OK due to bdrv_check_qiov_request(), bytes go to RawPosixAIOData::aio_nbytes which is uint64_t. Check also where that uint64_t gets handed: handle_aiocb_write_zeroes_block() passes a uint64_t[2] to ioctl(BLKZEROOUT), handle_aiocb_write_zeroes() calls do_fallocate() which takes off_t (and we compile to always have 64-bit off_t), as does handle_aiocb_write_zeroes_unmap. All look safe. gluster: bytes go to GlusterAIOCB::size which is int64_t and to glfs_zerofill_async works with off_t. iscsi: Aha, here we deal with iscsi_writesame16_task() that has uint32_t num_blocks argument and iscsi_writesame16_task() has uint16_t argument. Make comments, add assertions and clarify max_pwrite_zeroes calculation. iscsi_allocmap_() functions already has int64_t argument is_byte_request_lun_aligned is simple to update, do it. mirror_top: pass to bdrv_mirror_top_do_write which has uint64_t argument nbd: Aha, here we have protocol limitation, and NBDRequest::len is uint32_t. max_pwrite_zeroes is cleanly set to 32bit value, so we are OK for now. nvme: Again, protocol limitation. And no inherent limit for write-zeroes at all. But from code that calculates cdw12 it's obvious that we do have limit and alignment. Let's clarify it. Also, obviously the code is not prepared to handle bytes=0. Let's handle this case too. trace events already 64bit preallocate: pass to handle_write() and bdrv_co_pwrite_zeroes(), both 64bit. rbd: pass to qemu_rbd_start_co() which is 64bit. qcow2: offset + bytes and alignment still works good (thanks to bdrv_check_qiov_request()), so tail calculation is OK qcow2_subcluster_zeroize() has 64bit argument, should be OK trace events updated qed: qed_co_request wants int nb_sectors. Also in code we have size_t used for request length which may be 32bit. So, let's just keep INT_MAX as a limit (aligning it down to pwrite_zeroes_alignment) and don't care. raw-format: Is OK. raw_adjust_offset and bdrv_co_pwrite_zeroes are both 64bit. throttle: Both throttle_group_co_io_limits_intercept() and bdrv_co_pwrite_zeroes() are 64bit. vmdk: pass to vmdk_pwritev which is 64bit quorum: pass to quorum_co_pwritev() which is 64bit Hooray! At this point all block drivers are prepared to support 64bit write-zero requests, or have explicitly set max_pwrite_zeroes. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-8-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: use <= rather than < in assertions relying on max_pwrite_zeroes] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29block: use int64_t instead of uint64_t in driver write handlersVladimir 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 driver write handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_pwritev\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_pwritev() and bdrv_driver_pwritev_compressed() in block/io.c, both pass int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_save_vmstate() does bdrv_check_qiov_request(). Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_pwritev\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done shows several callers: qcow2: qcow2_co_truncate() write at most up to @offset, which is checked in generic qcow2_co_truncate() by bdrv_check_request(). qcow2_co_pwritev_compressed_task() pass the request (or part of the request) that already went through normal write path, so it should be OK qcow: qcow_co_pwritev_compressed() pass int64_t, it's updated by this patch quorum: quorum_co_pwrite_zeroes() pass int64_t and int - OK throttle: throttle_co_pwritev_compressed() pass int64_t, it's updated by this patch vmdk: vmdk_co_pwritev_compressed() pass int64_t, it's updated by this patch Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29block: use int64_t instead of uint64_t in driver read handlersVladimir 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 driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix typos] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-01block/block-copy: block_copy_state_new(): drop extra argumentsVladimir Sementsov-Ogievskiy
The only caller pass copy_range and compress both false. Let's just drop these arguments. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210824083856.17408-35-vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: make public block driverVladimir Sementsov-Ogievskiy
Finally, copy-before-write gets own .bdrv_open and .bdrv_close handlers, block_init() call and becomes available through bdrv_open(). To achieve this: - cbw_init gets unused flags argument and becomes cbw_open - block_copy_state_free() call moved to new cbw_close() - in bdrv_cbw_append: - options are completed with driver and node-name, and we can simply use bdrv_insert_node() to do both open and drained replacing - in bdrv_cbw_drop: - cbw_close() is now responsible for freeing s->bcs, so don't do it here Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-22-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: initialize block-copy bitmapVladimir Sementsov-Ogievskiy
We are going to publish copy-before-write filter to be used in separate of backup. Future step would support bitmap for the filter. But let's start from full set bitmap. We have to modify backup, as bitmap is first initialized by copy-before-write filter, and then backup modifies it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-20-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: cbw_init(): use optionsVladimir Sementsov-Ogievskiy
One more step closer to .bdrv_open(): use options instead of plain arguments. Move to bdrv_open_child() calls, native for drive open handlers. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210824083856.17408-19-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: bdrv_cbw_append(): drop unused compress argVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210824083856.17408-18-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: cbw_init(): use file child after attachingVladimir Sementsov-Ogievskiy
In the next commit we'll get rid of source argument of cbw_init(). Prepare to it now, to make next commit simpler: move the code block that uses source below attaching the child and use bs->file->bs instead of source variable. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-17-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: cbw_init(): rename variablesVladimir Sementsov-Ogievskiy
One more step closer to real .bdrv_open() handler: use more usual names for bs being initialized and its state. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-16-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: introduce cbw_init()Vladimir Sementsov-Ogievskiy
Move part of bdrv_cbw_append() to new function cbw_open(). It's an intermediate step for adding normal .bdrv_open() handler to the filter. With this commit no logic is changed, but we have a function which will be turned into .bdrv_open() handler in future commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-15-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: bdrv_cbw_append(): replace child at lastVladimir Sementsov-Ogievskiy
Refactor the function to replace child at last. Thus we don't need to revert it and code is simplified. block-copy state initialization being done before replacing the child doesn't need any drained section. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-14-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: use file child instead of backingVladimir Sementsov-Ogievskiy
We are going to publish copy-before-write filter, and there no public backing-child-based filter in Qemu. No reason to create a precedent, so let's refactor copy-before-write filter instead. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-13-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: drop extra bdrv_unref on failure pathVladimir Sementsov-Ogievskiy
bdrv_attach_child() do bdrv_unref() on failure, so we shouldn't do it by hand here. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-12-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/copy-before-write: relax permission requirements when no parentsVladimir Sementsov-Ogievskiy
We are going to publish copy-before-write filter. So, user should be able to create it with blockdev-add first, specifying both filtered and target children. And then do blockdev-reopen, to actually insert the filter where needed. Currently, filter unshares write permission unconditionally on source node. It's good, but it will not allow to do blockdev-add. So, let's relax restrictions when filter doesn't have any parent. Test output is modified, as now permission conflict happens only when job creates a blk parent for filter node. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-11-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/backup: move cluster size calculation to block-copyVladimir Sementsov-Ogievskiy
The main consumer of cluster-size is block-copy. Let's calculate it here instead of passing through backup-top. We are going to publish copy-before-write filter soon, so it will be created through options. But we don't want for now to make explicit option for cluster-size, let's continue to calculate it automatically. So, now is the time to get rid of cluster_size argument for bdrv_cbw_append(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-10-vsementsov@virtuozzo.com> [hreitz: Add qemu/error-report.h include to block/block-copy.c] Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block/backup: set copy_range and compress after filter insertionVladimir Sementsov-Ogievskiy
We are going to publish copy-before-write filter, so it would be initialized through options. Still we don't want to publish compress and copy-range options, as 1. Modern way to enable compression is to use compress filter. 2. For copy-range it's unclean how to make proper interface: - it's has experimental prefix for backup job anyway - the whole BackupPerf structure doesn't make sense for the filter So, let's just add copy-range possibility to the filter later if needed. Still, we are going to continue support for compression and experimental copy-range in backup job. So, set these options after filter creation. Note, that we can drop "compress" argument of bdrv_cbw_append() now, as well as "perf". The only reason not doing so is that now, when I prepare this patch the big series around it is already reviewed and I want to avoid extra rebase conflicts to simplify review of the following version. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210824083856.17408-9-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block-copy: move detecting fleecing scheme to block-copyVladimir Sementsov-Ogievskiy
We want to simplify initialization interface of copy-before-write filter as we are going to make it public. So, let's detect fleecing scheme exactly in block-copy code, to not pass this information through extra levels. Why not just set BDRV_REQ_SERIALISING unconditionally: because we are going to implement new more efficient fleecing scheme which will not rely on backing feature. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210824083856.17408-7-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block: rename backup-top to copy-before-writeVladimir Sementsov-Ogievskiy
We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>