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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>
2023-11-07block: Mark bdrv_has_zero_init() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_has_zero_init() need to hold a reader lock for the graph because it calls bdrv_filter_bs(), which accesses bs->file/backing. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20231027155333.420094-3-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-01cpr: relax blockdev migration blockersSteve Sistare
Some blockdevs block migration because they do not support sharing across hosts and/or do not support dirty bitmaps. These prohibitions do not apply if the old and new qemu processes do not run concurrently, and if new qemu starts on the same host as old, which is the case for cpr. Narrow the scope of these blockers so they only apply to normal mode. They will not block cpr modes when they are added in subsequent patches. No functional change until a new mode is added. Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <1698263069-406971-4-git-send-email-steven.sistare@oracle.com>
2023-10-20migration: simplify blockersSteve Sistare
Modify migrate_add_blocker and migrate_del_blocker to take an Error ** reason. This allows migration to own the Error object, so that if an error occurs in migrate_add_blocker, migration code can free the Error and clear the client handle, simplifying client code. It also simplifies the migrate_del_blocker call site. In addition, this is a pre-requisite for a proposed future patch that would add a mode argument to migration requests to support live update, and maintain a list of blockers for each mode. A blocker may apply to a single mode or to multiple modes, and passing Error** will allow one Error object to be registered for multiple modes. No functional change. Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Tested-by: Michael Galaxy <mgalaxy@akamai.com> Reviewed-by: Michael Galaxy <mgalaxy@akamai.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>
2023-10-12block: Mark bdrv_get_parent_name() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_get_parent_name() need to hold a reader lock for the graph because it accesses the parents list of a node. 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: <20230929145157.45443-13-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-09-08block/vpc: Avoid dynamic stack allocationPhilippe Mathieu-Daudé
Use autofree heap allocation instead of variable-length array on the stack. Here we don't expect the bitmap size to be enormous, and since we're about to read/write it to disk the overhead of the allocation should be fine. The codebase has very few VLAs, and if we can get rid of them all we can make the compiler error on new additions. This is a defensive measure against security bugs where an on-stack dynamic allocation isn't correctly size-checked (e.g. CVE-2021-3527). Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> [PMM: expanded commit message] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-ID: <20230811175229.808139-1-peter.maydell@linaro.org> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28vpc: mark more functions as coroutine_fns and GRAPH_RDLOCKPaolo Bonzini
Mark functions as coroutine_fn when they are only called by other coroutine_fns and they can suspend. Change calls to co_wrappers to use the non-wrapped functions, which in turn requires adding GRAPH_RDLOCK annotations. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20230601115145.196465-4-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19block: Call .bdrv_co_create(_opts) unlockedKevin Wolf
These are functions that modify the graph, so they must be able to take a writer lock. This is impossible if they already hold the reader lock. If they need a reader lock for some of their operations, they should take it internally. Many of them go through blk_*(), which will always take the lock itself. Direct calls of bdrv_*() need to take the reader lock. Note that while locking for bdrv_co_*() calls is checked by TSA, this is not the case for the mixed_coroutine_fns bdrv_*(). Holding the lock is still required when they are called from coroutine context like here! This effectively reverts 4ec8df0183, but adds some internal locking instead. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230510203601.418015-2-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10block: bdrv/blk_co_unref() for calls in coroutine contextKevin Wolf
These functions must not be called in coroutine context, because they need write access to the graph. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230504115750.54437-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_create() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_create() need to hold a reader lock for the graph. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-17-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>
2023-02-17vpc: Fix .bdrv_co_create(_opts) to open images with no_co_wrapperKevin Wolf
.bdrv_co_create implementations run in a coroutine. Therefore they are not allowed to open images directly. Fix the calls to use the corresponding no_co_wrappers instead. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230126172432.436111-12-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_get_info() to co_wrapper_mixedEmanuele Giuseppe Esposito
bdrv_get_info() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. Therefore turn it into a co_wrapper to move the actual function into a coroutine where the lock can be taken. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-11-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15block: bdrv_create_file is a coroutine_fnEmanuele Giuseppe Esposito
It is always called in coroutine_fn callbacks, therefore it can directly call bdrv_co_create(). Rename it to bdrv_co_create_file too. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20221128142337.657646-9-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@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>
2022-07-12block: Change blk_{pread,pwrite}() param orderAlberto Faria
Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12block: Change bdrv_{pread,pwrite,pwrite_sync}() param orderAlberto Faria
Swap 'buf' and 'bytes' around for consistency with bdrv_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pread(child, offset, buf, bytes, flags) + bdrv_pread(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite(child, offset, buf, bytes, flags) + bdrv_pwrite(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite_sync(child, offset, buf, bytes, flags) + bdrv_pwrite_sync(child, offset, bytes, buf, flags) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-3-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12block: Add a 'flags' param to bdrv_{pread,pwrite,pwrite_sync}()Alberto Faria
For consistency with other I/O functions, and in preparation to implement them using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes; @@ - bdrv_pread(child, offset, buf, bytes) + bdrv_pread(child, offset, buf, bytes, 0) @@ expression child, offset, buf, bytes; @@ - bdrv_pwrite(child, offset, buf, bytes) + bdrv_pwrite(child, offset, buf, bytes, 0) @@ expression child, offset, buf, bytes; @@ - bdrv_pwrite_sync(child, offset, buf, bytes) + bdrv_pwrite_sync(child, offset, buf, bytes, 0) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-2-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07osdep: Move memalign-related functions to their own headerPeter Maydell
Move the various memalign-related functions out of osdep.h and into their own header, which we include only where they are used. While we're doing this, add some brief documentation comments. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
2021-11-02block/vpc: Add a sanity check that fixed-size images have the right typeThomas Huth
The code in vpc.c uses BDRVVPCState->footer.type in various places to decide whether the image is a fixed-size (VHD_FIXED) or a dynamic (VHD_DYNAMIC) image. However, we never check that this field really contains VHD_FIXED if we detected a fixed size image in vpc_open(), so a wrong value here could cause quite some trouble during runtime. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20211012082702.792259-1-thuth@redhat.com> Signed-off-by: Hanna Reitz <hreitz@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>
2020-12-18block/vpc: Use sizeof() instead of HEADER_SIZE for footer sizeMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-10-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Pass footer buffers as VHDFooter * instead of uint8_t *Markus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-9-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Pad VHDFooter, replace uint8_t[] buffersMarkus Armbruster
Pad VHDFooter as specified in the "Virtual Hard Disk Image Format Specification" version 1.0[*]. Change footer buffers from uint8_t[HEADER_SIZE] to VHDFooter. Their size remains the same. The VHDFooter * variables pointing to a VHDFooter variable right next to it are now silly. Eliminate them, and shorten the remaining variables' names. Most variables pointing to s->footer are now also silly. Eliminate them, too. [*] http://download.microsoft.com/download/f/f/e/ffef50a5-07dd-4cf8-aaa3-442c0673a029/Virtual%20Hard%20Disk%20Format%20Spec_10_18_06.doc Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-8-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Use sizeof() instead of 1024 for dynamic header sizeMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-7-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Pad VHDDynDiskHeader, replace uint8_t[] buffersMarkus Armbruster
Pad VHDDynDiskHeader as specified in the "Virtual Hard Disk Image Format Specification" version 1.0[*]. Change dynamic disk header buffers from uint8_t[1024] to VHDDynDiskHeader. Their size remains the same. The VHDDynDiskHeader * variables pointing to a VHDDynDiskHeader variable right next to it are now silly. Eliminate them. [*] http://download.microsoft.com/download/f/f/e/ffef50a5-07dd-4cf8-aaa3-442c0673a029/Virtual%20Hard%20Disk%20Format%20Spec_10_18_06.doc Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-6-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Make vpc_checksum() take void *Markus Armbruster
Some of the next commits will checksum structs. Change vpc_checksum() to take void * instead of uint8_t, to save us pointless casts to uint8_t *. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-5-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Don't abuse the footer buffer for dynamic headerMarkus Armbruster
create_dynamic_disk() takes a buffer holding the footer as first argument. It writes out the footer (512 bytes), then reuses the buffer to initialize and write out the dynamic header (1024 bytes). Works, because the caller passes a buffer that is large enough for both purposes. I hate that. Use a separate buffer for the dynamic header, and adjust the caller's buffer. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-4-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Don't abuse the footer buffer as BAT sector bufferMarkus Armbruster
create_dynamic_disk() takes a buffer holding the footer as first argument. It writes out the footer (512 bytes), then reuses the buffer to initialize and write out the dynamic header (1024 bytes), then reuses it again to initialize and write out BAT sectors (512). Works, because the caller passes a buffer that is large enough for all three purposes. I hate that. Use a separate buffer for writing out BAT sectors. The next commit will do the same for the dynamic header. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-3-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-18block/vpc: Make vpc_open() read the full dynamic headerMarkus Armbruster
The dynamic header's size is 1024 bytes. vpc_open() reads only the 512 bytes of the dynamic header into buf[]. Works, because it doesn't actually access the second half. However, a colleague told me that GCC 11 warns: ../block/vpc.c:358:51: error: array subscript 'struct VHDDynDiskHeader[0]' is partly outside array bounds of 'uint8_t[512]' [-Werror=array-bounds] Clean up to read the full header. Rename buf[] to dyndisk_header_buf[] while there. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201217162003.1102738-2-armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-11-09block: Fix some code style problems, "foo* bar" should be "foo *bar"shiliyang
There have some code style problems be found when read the block driver code. So I fixes some problems of this error, ERROR: "foo* bar" should be "foo *bar". Signed-off-by: Liyang Shi <shiliyang@huawei.com> Reported-by: Euler Robot <euler.robot@huawei.com> Message-Id: <3211f389-6d22-46c1-4a16-e6a2ba66f070@huawei.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-10error: Avoid error_propagate() after migrate_add_blocker()Markus Armbruster
When migrate_add_blocker(blocker, &errp) is followed by error_propagate(errp, err), we can often just as well do migrate_add_blocker(..., errp). Do that with this Coccinelle script: @@ expression blocker, err, errp; expression ret; @@ - ret = migrate_add_blocker(blocker, &err); - if (err) { + ret = migrate_add_blocker(blocker, errp); + if (ret < 0) { ... when != err; - error_propagate(errp, err); ... } @@ expression blocker, err, errp; @@ - migrate_add_blocker(blocker, &err); - if (err) { + if (migrate_add_blocker(blocker, errp) < 0) { ... when != err; - error_propagate(errp, err); ... } Double-check @err is not used afterwards. Dereferencing it would be use after free, but checking whether it's null would be legitimate. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200707160613.848843-43-armbru@redhat.com>
2020-07-10qapi: Smooth another visitor error checking patternMarkus Armbruster
Convert visit_type_FOO(v, ..., &ptr, &err); ... if (err) { ... } to visit_type_FOO(v, ..., &ptr, errp); ... if (!ptr) { ... } for functions that set @ptr to non-null / null on success / error. Eliminate error_propagate() that are now unnecessary. Delete @err that are now unused. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-40-armbru@redhat.com>
2020-07-10error: Eliminate error_propagate() with Coccinelle, part 2Markus Armbruster
When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. The previous commit did that with a Coccinelle script I consider fairly trustworthy. This commit uses the same script with the matching of return taken out, i.e. we convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... } to if (!foo(..., errp)) { ... ... } This is unsound: @err could still be read between afterwards. I don't know how to express "no read of @err without an intervening write" in Coccinelle. Instead, I manually double-checked for uses of @err. Suboptimal line breaks tweaked manually. qdev_realize() simplified further to placate scripts/checkpatch.pl. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-36-armbru@redhat.com>
2020-07-10error: Eliminate error_propagate() with Coccinelle, part 1Markus Armbruster
When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. Convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... return ... } to if (!foo(..., errp)) { ... ... return ... } where nothing else needs @err. Coccinelle script: @rule1 forall@ identifier fun, err, errp, lbl; expression list args, args2; binary operator op; constant c1, c2; symbol false; @@ if ( ( - fun(args, &err, args2) + fun(args, errp, args2) | - !fun(args, &err, args2) + !fun(args, errp, args2) | - fun(args, &err, args2) op c1 + fun(args, errp, args2) op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; ) } @rule2 forall@ identifier fun, err, errp, lbl; expression list args, args2; expression var; binary operator op; constant c1, c2; symbol false; @@ - var = fun(args, &err, args2); + var = fun(args, errp, args2); ... when != err if ( ( var | !var | var op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; | return var; ) } @depends on rule1 || rule2@ identifier err; @@ - Error *err = NULL; ... when != err Not exactly elegant, I'm afraid. The "when != lbl:" is necessary to avoid transforming if (fun(args, &err)) { goto out } ... out: error_propagate(errp, err); even though other paths to label out still need the error_propagate(). For an actual example, see sclp_realize(). Without the "when strict", Coccinelle transforms vfio_msix_setup(), incorrectly. I don't know what exactly "when strict" does, only that it helps here. The match of return is narrower than what I want, but I can't figure out how to express "return where the operand doesn't use @err". For an example where it's too narrow, see vfio_intx_enable(). Silently fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Converted manually. Line breaks tidied up manually. One nested declaration of @local_err deleted manually. Preexisting unwanted blank line dropped in hw/riscv/sifive_e.c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10qemu-option: Use returned bool to check for failureMarkus Armbruster
The previous commit enables conversion of foo(..., &err); if (err) { ... } to if (!foo(..., &err)) { ... } for QemuOpts functions that now return true / false on success / error. Coccinelle script: @@ identifier fun = { opts_do_parse, parse_option_bool, parse_option_number, parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set, qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict, qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set, qemu_opts_validate }; expression list args, args2; typedef Error; Error *err; @@ - fun(args, &err, args2); - if (err) + if (!fun(args, &err, args2)) { ... } A few line breaks tidied up manually. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200707160613.848843-15-armbru@redhat.com> [Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend options" resolved by rerunning Coccinelle on master's version]
2020-07-06block/vpc: return ZERO block-status when appropriateVladimir Sementsov-Ogievskiy
In case when get_image_offset() returns -1, we do zero out the corresponding chunk of qiov. So, this should be reported as ZERO. Note that this changes visible output of "qemu-img map --output=json" and "qemu-io -c map" commands. For qemu-img map, the change is obvious: we just mark as zero what is really zero. For qemu-io it's less obvious: what was unallocated now is allocated. There is an inconsistency in understanding of unallocated regions in Qemu: backing-supporting format-drivers return 0 block-status to report go-to-backing logic for this area. Some protocol-drivers (iscsi) return 0 to report fs-unallocated-non-zero status (i.e., don't occupy space on disk, read result is undefined). BDRV_BLOCK_ALLOCATED is defined as something more close to go-to-backing logic. Still it is calculated as ZERO | DATA, so 0 from iscsi is treated as unallocated. It doesn't influence backing-chain behavior, as iscsi can't have backing file. But it does influence "qemu-io -c map". We should solve this inconsistency at some future point. Now, let's just make backing-not-supporting format drivers (vdi in the previous patch and vpc now) to behave more like backing-supporting drivers and not report 0 block-status. More over, returning ZERO status is absolutely valid thing, and again, corresponds to how the other format-drivers (backing-supporting) work. After block-status update, it never reports 0, so setting unallocated_blocks_are_zero doesn't make sense (as the only user of it is bdrv_co_block_status and it checks unallocated_blocks_are_zero only for unallocated areas). Drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200528094405.145708-5-vsementsov@virtuozzo.com> [mreitz: qemu-io -c map as used by iotest 146 now reports everything as allocated; in order to make the test do something useful, we use qemu-img map --output=json now] Signed-off-by: Max Reitz <mreitz@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>
2020-05-18block: 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: 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 BlockDriver.is_formatMax Reitz
We want to unify child_format and child_file at some point. One of the important things that set format drivers apart from other drivers is that they do not expect other format nodes under them (except in the backing chain), i.e. we must not probe formats inside of formats. That means we need something on which to distinguish format drivers from others, and hence this flag. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20200513110544.176672-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-05block: Add blk_new_with_bs() helperEric Blake
There are several callers that need to create a new block backend from an existing BDS; make the task slightly easier with a common helper routine. Suggested-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200424190903.522087-2-eblake@redhat.com> [mreitz: Set @ret only in error paths, see https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html] Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200428192648.749066-2-eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-04-30block-backend: Add flags to blk_truncate()Kevin Wolf
Now that node level interface bdrv_truncate() supports passing request flags to the block driver, expose this on the BlockBackend level, too. 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: <20200424125448.63318-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-07vpc: Don't round up already aligned BAT sizesKevin Wolf
As reported on Launchpad, Azure apparently doesn't accept images for upload that are not both aligned to 1 MB blocks and have a BAT size that matches the image size exactly. As far as I can tell, there is no real reason why we create a BAT that is one entry longer than necessary for aligned image sizes, so change that. (Even though the condition is only mentioned as "should" in the spec and previous products accepted larger BATs - but we'll try to maintain compatibility with as many of Microsoft's ever-changing interpretations of the VHD spec as possible.) Fixes: https://bugs.launchpad.net/bugs/1870098 Reported-by: Tobias Witek Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20200402093603.2369-1-kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-26block: pass BlockDriver reference to the .bdrv_co_createMaxim Levitsky
This will allow the reuse of a single generic .bdrv_co_create implementation for several drivers. No functional changes. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> 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>
2019-09-10vpc: Return 0 from vpc_co_create() on successMax Reitz
blockdev_create_run() directly uses .bdrv_co_create()'s return value as the job's return value. Jobs must return 0 on success, not just any nonnegative value. Therefore, using blockdev-create for VPC images may currently fail as the vpc driver may return a positive integer. Because there is no point in returning a positive integer anywhere in the block layer (all non-negative integers are generally treated as complete success), we probably do not want to add more such cases. Therefore, fix this problem by making the vpc driver always return 0 in case of success. Suggested-by: Kevin Wolf <kwolf@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-08-19vpc: Do not return RAW from block_statusMax Reitz
vpc is not really a passthrough driver, even when using the fixed subformat (where host and guest offsets are equal). It should handle preallocation like all other drivers do, namely by returning DATA | RECURSE instead of RAW. There is no tangible difference but the fact that bdrv_is_allocated() no longer falls through to the protocol layer. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190725155512.9827-4-mreitz@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-06-04block: Add BlockBackend.ctxKevin Wolf
This adds a new parameter to blk_new() which requires its callers to declare from which AioContext this BlockBackend is going to be used (or the locks of which AioContext need to be taken anyway). The given context is only stored and kept up to date when changing AioContexts. Actually applying the stored AioContext to the root node is saved for another commit. Signed-off-by: Kevin Wolf <kwolf@redhat.com>