- 09 3月, 2018 1 次提交
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由 Paolo Bonzini 提交于
QED's bdrv_invalidate_cache implementation would like to reuse functions that acquire/release the metadata locks. Call it from coroutine context to simplify the logic. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Message-Id: <1516279431-30424-6-git-send-email-pbonzini@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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- 03 3月, 2018 7 次提交
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由 Markus Armbruster 提交于
In my "build everything" tree, a change to the types in qapi-schema.json triggers a recompile of about 4800 out of 5100 objects. The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h, qapi-types.h. Each of these headers still includes all its shards. Reduce compile time by including just the shards we actually need. To illustrate the benefits: adding a type to qapi/migration.json now recompiles some 2300 instead of 4800 objects. The next commit will improve it further. Signed-off-by: NMarkus Armbruster <armbru@redhat.com> Message-Id: <20180211093607.27351-24-armbru@redhat.com> Reviewed-by: NEric Blake <eblake@redhat.com> Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com> [eblake: rebase to master] Signed-off-by: NEric Blake <eblake@redhat.com>
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由 Stefan Hajnoczi 提交于
BlockDriver->bdrv_create() has been called from coroutine context since commit 5b7e1542 ("block: make bdrv_create adopt coroutine"). Make this explicit by renaming to .bdrv_co_create_opts() and add the coroutine_fn annotation. This makes it obvious to block driver authors that they may yield, use CoMutex, or other coroutine_fn APIs. bdrv_co_create is reserved for the QAPI-based version that Kevin is working on. Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com> Message-Id: <20170705102231.20711-2-stefanha@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Reviewed-by: NEric Blake <eblake@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Stefan Hajnoczi 提交于
BlockDriverState has the BDRV_POLL_WHILE() macro to wait on event loop activity while a condition evaluates to true. This is used to implement synchronous operations where it acts as a condvar between the IOThread running the operation and the main loop waiting for the operation. It can also be called from the thread that owns the AioContext and in that case it's just a nested event loop. BlockBackend needs this behavior but doesn't always have a BlockDriverState it can use. This patch extracts BDRV_POLL_WHILE() into the AioWait abstraction, which can be used with AioContext and isn't tied to BlockDriverState anymore. This feature could be built directly into AioContext but then all users would kick the event loop even if they signal different conditions. Imagine an AioContext with many BlockDriverStates, each time a request completes any waiter would wake up and re-check their condition. It's nicer to keep a separate AioWait object for each condition instead. Please see "block/aio-wait.h" for details on the API. The name AIO_WAIT_WHILE() avoids the confusion between AIO_POLL_WHILE() and AioContext polling. Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com> Reviewed-by: NEric Blake <eblake@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Stefan Hajnoczi 提交于
The name aio_context_in_iothread() is misleading because it also returns true when called on the main AioContext from the main loop thread, which is not an IOThread. This patch renames it to in_aio_context_home_thread() and expands the doc comment to make the semantics clearer. Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com> Reviewed-by: NEric Blake <eblake@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Eric Blake 提交于
We are gradually moving away from sector-based interfaces, towards byte-based. Now that all drivers have been updated to provide the byte-based .bdrv_co_block_status(), we can delete the sector-based interface. Signed-off-by: NEric Blake <eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NFam Zheng <famz@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Eric Blake 提交于
We are gradually moving away from sector-based interfaces, towards byte-based. Update the generic helpers, and all passthrough clients (blkdebug, commit, mirror, throttle) accordingly. Signed-off-by: NEric Blake <eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NFam Zheng <famz@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Eric Blake 提交于
We are gradually moving away from sector-based interfaces, towards byte-based. Now that the block layer exposes byte-based allocation, it's time to tackle the drivers. Add a new callback that operates on as small as byte boundaries. Subsequent patches will then update individual drivers, then finally remove .bdrv_co_get_block_status(). The new code also passes through the 'want_zero' hint, which will allow subsequent patches to further optimize callers that only care about how much of the image is allocated (want_zero is false), rather than full details about runs of zeroes and which offsets the allocation actually maps to (want_zero is true). As part of this effort, fix another part of the documentation: the claim in commit 4c41cb49 that BDRV_BLOCK_ALLOCATED is short for 'DATA || ZERO' is a lie at the block layer (see commit e88ae226), even though it is how the bit is computed from the driver layer. After all, there are intentionally cases where we return ZERO but not ALLOCATED at the block layer, when we know that a read sees zero because the backing file is too short. Note that the driver interface is thus slightly different than the public interface with regards to which bits will be set, and what guarantees are provided on input. We also add an assertion that any driver using the new callback will make progress (the only time pnum will be 0 is if the block layer already handled an out-of-bounds request, or if there is an error); the old driver interface did not provide this guarantee, which could lead to some inf-loops in drastic corner-case failures. Signed-off-by: NEric Blake <eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NFam Zheng <famz@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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- 02 3月, 2018 2 次提交
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Expose the new constants and structs that will be used by both server and client implementations of NBD_CMD_BLOCK_STATUS (the command is currently experimental at https://github.com/NetworkBlockDevice/nbd/blob/extension-blockstatus/doc/proto.md but will hopefully be stabilized soon). Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <1518702707-7077-4-git-send-email-vsementsov@virtuozzo.com> [eblake: split from larger patch on server implementation] Signed-off-by: NEric Blake <eblake@redhat.com>
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Prepared indenting for the following patch. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <1518702707-7077-3-git-send-email-vsementsov@virtuozzo.com> Signed-off-by: NEric Blake <eblake@redhat.com>
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- 13 2月, 2018 1 次提交
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To maintain load/store disabled bitmap there is new approach: - deprecate @autoload flag of block-dirty-bitmap-add, make it ignored - store enabled bitmaps as "auto" to qcow2 - store disabled bitmaps without "auto" flag to qcow2 - on qcow2 open load "auto" bitmaps as enabled and others as disabled (except in_use bitmaps) Also, adjust iotests 165 and 176 appropriately. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20180202160752.143796-1-vsementsov@virtuozzo.com Signed-off-by: NMax Reitz <mreitz@redhat.com>
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- 10 2月, 2018 1 次提交
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由 Eric Blake 提交于
We don't need the can_write_zeroes_with_unmap field in BlockDriverInfo, because it is redundant information with supported_zero_flags & BDRV_REQ_MAY_UNMAP. Note that BlockDriverInfo and supported_zero_flags are both per-device settings, rather than global state about the driver as a whole, which means one or both of these bits of information can already be conditional. Let's audit how they were set: crypto: always setting can_write_ to false is pointless (the struct starts life zero-initialized), no use of supported_ nbd: just recently fixed to set can_write_ if supported_ includes MAY_UNMAP (thus this commit effectively reverts bca80059e and solves the problem mentioned there in a more global way) file-posix, iscsi, qcow2: can_write_ is conditional, while supported_ was unconditional; but passing MAY_UNMAP would fail with ENOTSUP if the condition wasn't met qed: can_write_ is unconditional, but pwrite_zeroes lacks support for MAY_UNMAP and supported_ is not set. Perhaps support can be added later (since it would be similar to qcow2), but for now claiming false is no real loss all other drivers: can_write_ is not set, and supported_ is either unset or a passthrough Simplify the code by moving the conditional into supported_zero_flags for all drivers, then dropping the now-unused BDI field. For callers that relied on bdrv_can_write_zeroes_with_unmap(), we return the same per-device settings for drivers that had conditions (no observable change in behavior there); and can now return true (instead of false) for drivers that support passthrough (for example, the commit driver) which gives those drivers the same fix as nbd just got in bca80059e. For callers that relied on supported_zero_flags, we now have a few more places that can avoid a wasted call to pwrite_zeroes() that will just fail with ENOTSUP. Suggested-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NEric Blake <eblake@redhat.com> Message-Id: <20180126193439.20219-1-eblake@redhat.com> Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
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- 09 2月, 2018 4 次提交
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由 Markus Armbruster 提交于
qemu-common.h includes qemu/option.h, but most places that include the former don't actually need the latter. Drop the include, and add it to the places that actually need it. While there, drop superfluous includes of both headers, and separate #include from file comment with a blank line. This cleanup makes the number of objects depending on qemu/option.h drop from 4545 (out of 4743) to 284 in my "build everything" tree. Reviewed-by: NEric Blake <eblake@redhat.com> Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: NMarkus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-20-armbru@redhat.com> [Semantic conflict with commit bdd6a90a in block/nvme.c resolved]
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由 Markus Armbruster 提交于
This cleanup makes the number of objects depending on qapi/qmp/qdict.h drop from 4550 (out of 4743) to 368 in my "build everything" tree. For qapi/qmp/qobject.h, the number drops from 4552 to 390. While there, separate #include from file comment with a blank line. Reviewed-by: NEric Blake <eblake@redhat.com> Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: NMarkus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-13-armbru@redhat.com>
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由 Markus Armbruster 提交于
Reviewed-by: NEric Blake <eblake@redhat.com> Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: NMarkus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-11-armbru@redhat.com>
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由 Markus Armbruster 提交于
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: NEric Blake <eblake@redhat.com> Signed-off-by: NMarkus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-4-armbru@redhat.com>
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- 08 2月, 2018 2 次提交
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由 Fam Zheng 提交于
Signed-off-by: NFam Zheng <famz@redhat.com> Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com> Message-Id: <20180116060901.17413-8-famz@redhat.com> Signed-off-by: NFam Zheng <famz@redhat.com>
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由 Fam Zheng 提交于
Allow block driver to map and unmap a buffer for later I/O, as a performance hint. Signed-off-by: NFam Zheng <famz@redhat.com> Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com> Message-Id: <20180116060901.17413-5-famz@redhat.com> Signed-off-by: NFam Zheng <famz@redhat.com>
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- 26 1月, 2018 1 次提交
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Add command for removing an export. It is needed for cases when we don't want to keep the export after the operation on it was completed. The other example is a temporary node, created with blockdev-add. If we want to delete it we should firstly remove any corresponding NBD export. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20180119135719.24745-3-vsementsov@virtuozzo.com> [eblake: drop dead nb_clients code] Signed-off-by: NEric Blake <eblake@redhat.com>
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- 11 1月, 2018 1 次提交
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Rename nbd_option and nbd_opt_reply to NBDOption and NBDOptionReply to correspond to Qemu coding style and other structures here. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NEric Blake <eblake@redhat.com> Message-Id: <20171122101958.17065-5-vsementsov@virtuozzo.com> Signed-off-by: NEric Blake <eblake@redhat.com>
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- 22 12月, 2017 4 次提交
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由 Kevin Wolf 提交于
We need to remember how many of the drain sections in which a node is were recursive (i.e. subtree drain rather than node drain), so that they can be correctly applied when children are added or removed during the drained section. With this change, it is safe to modify the graph even inside a bdrv_subtree_drained_begin/end() section. Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Kevin Wolf 提交于
bdrv_drained_begin() waits for the completion of requests in the whole subtree, but it only actually keeps its immediate bs parameter quiesced until bdrv_drained_end(). Add a version that keeps the whole subtree drained. As of this commit, graph changes cannot be allowed during a subtree drained section, but this will be fixed soon. Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Kevin Wolf 提交于
This is in preparation for subtree drains, i.e. drained sections that affect not only a single node, but recursively all child nodes, too. Calling the parent callbacks for drain is pointless when we just came from that parent node recursively and leads to multiple increases of bs->quiesce_counter in a single drain call. Don't do it. In order for this to work correctly, the parent callback must be called for every bdrv_drain_begin/end() call, not only for the outermost one: If we have a node N with two parents A and B, recursive draining of A should cause the quiesce_counter of B to increase because its child N is drained independently of B. If now B is recursively drained, too, A must increase its quiesce_counter because N is drained independently of A only now, even if N is going from quiesce_counter 1 to 2. Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Fam Zheng 提交于
Signed-off-by: NFam Zheng <famz@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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- 18 12月, 2017 1 次提交
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The function searches for next zero bit. Also add interface for BdrvDirtyBitmap and unit test. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NJohn Snow <jsnow@redhat.com> Message-id: 20171012135313.227864-2-vsementsov@virtuozzo.com Signed-off-by: NJeff Cody <jcody@redhat.com>
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- 29 11月, 2017 2 次提交
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由 Paolo Bonzini 提交于
This reverts the effects of commit 4afeffc8 ("blockjob: do not allow coroutine double entry or entry-after-completion", 2017-11-21) This fixed the symptom of a bug rather than the root cause. Canceling the wait on a sleeping blockjob coroutine is generally fine, we just need to make it work correctly across AioContexts. To do so, use a QEMUTimer that calls block_job_enter. Use a mutex to ensure that block_job_enter synchronizes correctly with block_job_sleep_ns. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Tested-By: NJeff Cody <jcody@redhat.com> Reviewed-by: NFam Zheng <famz@redhat.com> Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com> Reviewed-by: NJeff Cody <jcody@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Paolo Bonzini 提交于
All callers are using QEMU_CLOCK_REALTIME, and it will not be possible to support more than one clock when block_job_sleep_ns switches to a single timer stored in the BlockJob struct. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Reviewed-by: NAlberto Garcia <berto@igalia.com> Tested-By: NJeff Cody <jcody@redhat.com> Reviewed-by: NFam Zheng <famz@redhat.com> Reviewed-by: NJeff Cody <jcody@redhat.com> Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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- 22 11月, 2017 1 次提交
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由 Jeff Cody 提交于
When block_job_sleep_ns() is called, the co-routine is scheduled for future execution. If we allow the job to be re-entered prior to the scheduled time, we present a race condition in which a coroutine can be entered recursively, or even entered after the coroutine is deleted. The job->busy flag is used by blockjobs when a coroutine is busy executing. The function 'block_job_enter()' obeys the busy flag, and will not enter a coroutine if set. If we sleep a job, we need to leave the busy flag set, so that subsequent calls to block_job_enter() are prevented. This changes the prior behavior of block_job_cancel() being able to immediately wake up and cancel a job; in practice, this should not be an issue, as the coroutine sleep times are generally very small, and the cancel will occur the next time the coroutine wakes up. This fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1508708Signed-off-by: NJeff Cody <jcody@redhat.com> Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
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- 21 11月, 2017 2 次提交
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由 Kevin Wolf 提交于
Signed-off-by: NKevin Wolf <kwolf@redhat.com> Reviewed-by: NEric Blake <eblake@redhat.com> Reviewed-by: NDenis V. Lunev <den@openvz.org> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NJohn Snow <jsnow@redhat.com>
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由 Kevin Wolf 提交于
Signed-off-by: NKevin Wolf <kwolf@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: NJohn Snow <jsnow@redhat.com>
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- 18 11月, 2017 1 次提交
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由 Max Reitz 提交于
On one hand, it is a good idea for bdrv_next() to return a strong reference because ideally nearly every pointer should be refcounted. This fixes intermittent failure of iotest 194. On the other, it is absolutely necessary for bdrv_next() itself to keep a strong reference to both the BB (in its first phase) and the BDS (at least in the second phase) because when called the next time, it will dereference those objects to get a link to the next one. Therefore, it needs these objects to stay around until then. Just storing the pointer to the next in the iterator is not really viable because that pointer might become invalid as well. Both arguments taken together means we should probably just invoke bdrv_ref() and blk_ref() in bdrv_next(). This means we have to assert that bdrv_next() is always called from the main loop, but that was probably necessary already before this patch and judging from the callers, it also looks to actually be the case. Keeping these strong references means however that callers need to give them up if they decide to abort the iteration early. They can do so through the new bdrv_next_cleanup() function. Suggested-by: NKevin Wolf <kwolf@redhat.com> Signed-off-by: NMax Reitz <mreitz@redhat.com> Message-id: 20171110172545.32609-1-mreitz@redhat.com Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com> Signed-off-by: NMax Reitz <mreitz@redhat.com>
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- 10 11月, 2017 1 次提交
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由 Eric Blake 提交于
A closer read of the NBD spec shows that a structured reply chunk for a hole is not quite identical to the prefix of a data chunk, because the hole has to also send a 32-bit size field. Although we do not yet send holes, we should fix the misleading information in our header and make it easier for a future patch to support sparse reads. Messed up in commit bae245d1. Signed-off-by: NEric Blake <eblake@redhat.com> Message-Id: <20171108215703.9295-5-eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
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- 31 10月, 2017 5 次提交
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Minimal implementation: for structured error only error_report error message. Note that test 83 is now more verbose, because the implementation prints more warnings about unexpected communication errors; perhaps future patches should tone things down by using trace messages instead of traces, but the common case of successful communication is no noisier than before. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: NEric Blake <eblake@redhat.com> Message-Id: <20171027104037.8319-13-eblake@redhat.com>
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由 Eric Blake 提交于
An upcoming change to block/nbd-client.c will want to read the tail of a structured reply chunk directly from the wire. Move this function to make it easier. Based on a patch from Vladimir Sementsov-Ogievskiy. Signed-off-by: NEric Blake <eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-12-eblake@redhat.com>
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In following patch nbd_receive_reply will be used both for simple and structured reply header receiving. NBDReply is altered into union of simple reply header and structured reply chunk header, simple error translation moved to block/nbd-client to be consistent with further structured reply error translation. Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: NEric Blake <eblake@redhat.com> Message-Id: <20171027104037.8319-11-eblake@redhat.com>
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由 Eric Blake 提交于
Upcoming patches will implement the NBD structured reply extension [1] for both client and server roles. Declare the constants, structs, and lookup routines that will be valuable whether the server or client code is backported in isolation. This includes moving one constant from an internal header to the public header, as part of the structured read processing will be done in block/nbd-client.c rather than nbd/client.c. [1]https://github.com/NetworkBlockDevice/nbd/blob/extension-structured-reply/doc/proto.md Based on patches from Vladimir Sementsov-Ogievskiy. Signed-off-by: NEric Blake <eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-4-eblake@redhat.com>
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由 Eric Blake 提交于
This is needed in preparation for structured reply handling, as we will be performing the translation from NBD error to system errno value higher in the stack at block/nbd-client.c. Signed-off-by: NEric Blake <eblake@redhat.com> Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20171027104037.8319-3-eblake@redhat.com>
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- 26 10月, 2017 3 次提交
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由 Eric Blake 提交于
Any device that has request_alignment greater than 512 should be unable to report status at a finer granularity; it may also be simpler for such devices to be guaranteed that the block layer has rounded things out to the granularity boundary (the way the block layer already rounds all other I/O out). Besides, getting the code correct for super-sector alignment also benefits us for the fact that our public interface now has byte granularity, even though none of our drivers have byte-level callbacks. Add an assertion in blkdebug that proves that the block layer never requests status of unaligned sections, similar to what it does on other requests (while still keeping the generic helper in place for when future patches add a throttle driver). Note that iotest 177 already covers this (it would fail if you use just the blkdebug.c hunk without the io.c changes). Meanwhile, we can drop assertions in callers that no longer have to pass in sector-aligned addresses. There is a mid-function scope added for 'count' and 'longret', for a couple of reasons: first, an upcoming patch will add an 'if' statement that checks whether a driver has an old- or new-style callback, and can conveniently use the same scope for less indentation churn at that time. Second, since we are trying to get rid of sector-based computations, wrapping things in a scope makes it easier to group and see what will be deleted in a final cleanup patch once all drivers have been converted to the new-style callback. Signed-off-by: NEric Blake <eblake@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Eric Blake 提交于
We are gradually moving away from sector-based interfaces, towards byte-based. In the common case, allocation is unlikely to ever use values that are not naturally sector-aligned, but it is possible that byte-based values will let us be more precise about allocation at the end of an unaligned file that can do byte-based access. Changing the name of the function from bdrv_get_block_status_above() to bdrv_block_status_above() ensures that the compiler enforces that all callers are updated. Likewise, since it a byte interface allows an offset mapping that might not be sector aligned, split the mapping out of the return value and into a pass-by-reference parameter. For now, the io.c layer still assert()s that all uses are sector-aligned, but that can be relaxed when a later patch implements byte-based block status in the drivers. For the most part this patch is just the addition of scaling at the callers followed by inverse scaling at bdrv_block_status(), plus updates for the new split return interface. But some code, particularly bdrv_block_status(), gets a lot simpler because it no longer has to mess with sectors. Likewise, mirror code no longer computes s->granularity >> BDRV_SECTOR_BITS, and can therefore drop an assertion about alignment because the loop no longer depends on alignment (never mind that we don't really have a driver that reports sub-sector alignments, so it's not really possible to test the effect of sub-sector mirroring). Fix a neighboring assertion to use is_power_of_2 while there. For ease of review, bdrv_get_block_status() was tackled separately. Signed-off-by: NEric Blake <eblake@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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由 Eric Blake 提交于
We are gradually moving away from sector-based interfaces, towards byte-based. In the common case, allocation is unlikely to ever use values that are not naturally sector-aligned, but it is possible that byte-based values will let us be more precise about allocation at the end of an unaligned file that can do byte-based access. Changing the name of the function from bdrv_get_block_status() to bdrv_block_status() ensures that the compiler enforces that all callers are updated. For now, the io.c layer still assert()s that all callers are sector-aligned, but that can be relaxed when a later patch implements byte-based block status in the drivers. There was an inherent limitation in returning the offset via the return value: we only have room for BDRV_BLOCK_OFFSET_MASK bits, which means an offset can only be mapped for sector-aligned queries (or, if we declare that non-aligned input is at the same relative position modulo 512 of the answer), so the new interface also changes things to return the offset via output through a parameter by reference rather than mashed into the return value. We'll have some glue code that munges between the two styles until we finish converting all uses. For the most part this patch is just the addition of scaling at the callers followed by inverse scaling at bdrv_block_status(), coupled with the tweak in calling convention. But some code, particularly bdrv_is_allocated(), gets a lot simpler because it no longer has to mess with sectors. For ease of review, bdrv_get_block_status_above() will be tackled separately. Signed-off-by: NEric Blake <eblake@redhat.com> Signed-off-by: NKevin Wolf <kwolf@redhat.com>
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