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2017-04-11block: Make bdrv_parent_drained_begin/end publicFam Zheng1-2/+2
Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-07block: Don't check permissions for copy on readKevin Wolf1-1/+8
The assertion is currently failing. We can't require callers to have write permissions when all they are doing is a read, so comment it out. Add a FIXME comment in the code so that the check is re-enabled when copy on read is refactored into its own filter driver. Reported-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
2017-03-13block: Request block status from *file for BDRV_BLOCK_RAWKevin Wolf1-1/+1
This fixes bdrv_co_get_block_status() for the bdrv_mirror_top block driver, which must fall through to bs->backing instead of bs->file. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-02-28block: Assertions for resize permissionKevin Wolf1-0/+1
This adds an assertion that ensures that the necessary resize permission has been granted before bdrv_truncate() is called. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Assertions for write permissionsKevin Wolf1-0/+3
This adds assertions that ensure that the necessary write permissions have been granted before someone attempts to write to a node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Pass BdrvChild to bdrv_aligned_preadv/pwritev and copy-on-readKevin Wolf1-16/+21
This is where we want to check the permissions, so we need to have the BdrvChild around where they are stored. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-21coroutine-lock: add mutex argument to CoQueue APIsPaolo Bonzini1-2/+2
All that CoQueue needs in order to become thread-safe is help from an external mutex. Add this to the API. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-6-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: explicitly acquire aiocontext in aio callbacks that need itPaolo Bonzini1-5/+1
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-16-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: explicitly acquire aiocontext in bottom halves that need itPaolo Bonzini1-1/+5
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-15-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: explicitly acquire aiocontext in timers that need itPaolo Bonzini1-0/+5
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-13-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: move AioContext, QEMUTimer, main-loop to libqemuutilPaolo Bonzini1-29/+0
AioContext is fairly self contained, the only dependency is QEMUTimer but that in turn doesn't need anything else. So move them out of block-obj-y to avoid introducing a dependency from io/ to block-obj-y. main-loop and its dependency iohandler also need to be moved, because later in this series io/ will call iohandler_get_aio_context. [Changed copyright "the QEMU team" to "other QEMU contributors" as suggested by Daniel Berrange and agreed by Paolo. --Stefan] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213135235.12274-2-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-16block: get rid of bdrv_io_unplugged_begin/endPaolo Bonzini1-39/+2
bdrv_io_plug and bdrv_io_unplug are only called (via their BlockBackend equivalents) after starting asynchronous I/O. bdrv_drain is not going to be called while they are running, because---even if a coroutine runs for some reason---it will only drain in the next iteration of the event loop through bdrv_co_yield_to_drain. So this mechanism is unnecessary, get rid of it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161129113334.605-1-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-11-22block: Pass unaligned discard requests to driversEric Blake1-13/+32
Discard is advisory, so rounding the requests to alignment boundaries is never semantically wrong from the data that the guest sees. But at least the Dell Equallogic iSCSI SANs has an interesting property that its advertised discard alignment is 15M, yet documents that discarding a sequence of 1M slices will eventually result in the 15M page being marked as discarded, and it is possible to observe which pages have been discarded. Between commits 9f1963b and b8d0a980, we converted the block layer to a byte-based interface that ultimately ignores any unaligned head or tail based on the driver's advertised discard granularity, which means that qemu 2.7 refuses to pass any discard request smaller than 15M down to the Dell Equallogic hardware. This is a slight regression in behavior compared to earlier qemu, where a guest executing discards in power-of-2 chunks used to be able to get every page discarded, but is now left with various pages still allocated because the guest requests did not align with the hardware's 15M pages. Since the SCSI specification says nothing about a minimum discard granularity, and only documents the preferred alignment, it is best if the block layer gives the driver every bit of information about discard requests, rather than rounding it to alignment boundaries early. Rework the block layer discard algorithm to mirror the write zero algorithm: always peel off any unaligned head or tail and manage that in isolation, then do the bulk of the request on an aligned boundary. The fallback when the driver returns -ENOTSUP for an unaligned request is to silently ignore that portion of the discard request; but for devices that can pass the partial request all the way down to hardware, this can result in the hardware coalescing requests and discarding aligned pages after all. Reported by: Peter Lieven <pl@kamp.de> CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-22block: Let write zeroes fallback work even with small max_transferEric Blake1-5/+8
Commit 443668ca rewrote the write_zeroes logic to guarantee that an unaligned request never crosses a cluster boundary. But in the rewrite, the new code assumed that at most one iteration would be needed to get to an alignment boundary. However, it is easy to trigger an assertion failure: the Linux kernel limits loopback devices to advertise a max_transfer of only 64k. Any operation that requires falling back to writes rather than more efficient zeroing must obey max_transfer during that fallback, which means an unaligned head may require multiple iterations of the write fallbacks before reaching the aligned boundaries, when layering a format with clusters larger than 64k atop the protocol of file access to a loopback device. Test case: $ qemu-img create -f qcow2 -o cluster_size=1M file 10M $ losetup /dev/loop2 /path/to/file $ qemu-io -f qcow2 /dev/loop2 qemu-io> w 7m 1k qemu-io> w -z 8003584 2093056 In fairness to Denis (as the original listed author of the culprit commit), the faulty logic for at most one iteration is probably all my fault in reworking his idea. But the solution is to restore what was in place prior to that commit: when dealing with an unaligned head or tail, iterate as many times as necessary while fragmenting the operation at max_transfer boundaries. Reported-by: Ed Swierk <eswierk@skyportsystems.com> CC: qemu-stable@nongnu.org CC: Denis V. Lunev <den@openvz.org> Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-08block: Don't mark node clean after failed flushKevin Wolf1-1/+3
Commit 3ff2f67a changed bdrv_co_flush() so that no flush is issues if the image hasn't been dirtied since the last flush. This is not quite correct: The condition should be that the image hasn't been dirtied since the last _successful_ flush. This patch changes the logic accordingly. Without this fix, subsequent bdrv_co_flush() calls would return success without actually doing anything even though the image is still dirty. The difference is visible in some blkdebug test cases where error messages incorrectly disappeared after commit 3ff2f67a. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 1478300595-10090-1-git-send-email-kwolf@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-31block: Add bdrv_drain_all_{begin,end}()Alberto Garcia1-3/+24
bdrv_drain_all() doesn't allow the caller to do anything after all pending requests have been completed but before block jobs are resumed. This patch splits bdrv_drain_all() into _begin() and _end() for that purpose. It also adds aio_{disable,enable}_external() calls to disable external clients in the meantime. An important restriction of this split is that no new block jobs or BlockDriverStates can be created between the bdrv_drain_all_begin() and bdrv_drain_all_end() calls. This is not a concern now because we'll only be using this in bdrv_reopen_multiple(), but it must be dealt with if we ever have other uses cases in the future. Signed-off-by: Alberto Garcia <berto@igalia.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-28block: only call aio_poll on the current thread's AioContextPaolo Bonzini1-0/+12
aio_poll is not thread safe; for example bdrv_drain can hang if the last in-flight I/O operation is completed in the I/O thread after the main thread has checked bs->in_flight. The bug remains latent as long as all of it is called within aio_context_acquire/aio_context_release, but this will change soon. To fix this, if bdrv_drain is called from outside the I/O thread, signal the main AioContext through a dummy bottom half. The event loop then only runs in the I/O thread. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-18-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: introduce BDRV_POLL_WHILEPaolo Bonzini1-32/+5
We want the BDS event loop to run exclusively in the iothread that owns the BDS's AioContext. This macro will provide the synchronization between the two event loops; for now it just wraps the common idiom of a while loop around aio_poll. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-8-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: change drain to look only at one child at a timePaolo Bonzini1-21/+26
bdrv_requests_pending is checking children to also wait until internal requests (such as metadata writes) have completed. However, checking children is in general overkill. Children requests can be of two kinds: - requests caused by an operation on bs, e.g. a bdrv_aio_write to bs causing a write to bs->file->bs. In this case, the parent's in_flight count will always be incremented by at least one for every request in the child. - asynchronous metadata writes or flushes. Such writes can be started even if bs's in_flight count is zero, but not after the .bdrv_drain callback has been invoked. This patch therefore changes bdrv_drain to finish I/O in the parent (after which the parent's in_flight will be locked to zero), call bdrv_drain (after which the parent will not generate I/O on the child anymore), and then wait for internal I/O in the children to complete. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-6-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: add BDS field to count in-flight requestsPaolo Bonzini1-25/+50
Unlike tracked_requests, this field also counts throttled requests, and remains non-zero if an AIO operation needs a BH to be "really" completed. With this change, it is no longer necessary to have a dummy BdrvTrackedRequest for requests that are never serialising, and it is no longer necessary to poll the AioContext once after bdrv_requests_pending(bs) returns false. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-5-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-27block: Remove bdrv_aio_ioctl()Kevin Wolf1-27/+0
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Introduce .bdrv_co_ioctl() driver callbackKevin Wolf1-6/+10
This allows drivers to implement ioctls in a coroutine-based way. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Remove bdrv_ioctl()Kevin Wolf1-37/+0
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Use blk_co_ioctl() for all BB level ioctlsKevin Wolf1-4/+4
All read/write functions already have a single coroutine-based function on the BlockBackend level through which all requests go (no matter what API style the external caller used) and which passes the requests down to the block node level. This patch exports a bdrv_co_ioctl() function and uses it to extend this mode of operation to ioctls. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Remove bdrv_aio_pdiscard()Kevin Wolf1-29/+0
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-07block: use aio_bh_schedule_oneshotPaolo Bonzini1-8/+3
This simplifies bottom half handlers by removing calls to qemu_bh_delete and thus removing the need to stash the bottom half pointer in the opaque datum. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-29block: reintroduce bdrv_flush_allJohn Snow1-0/+25
Commit fe1a9cbc moved the flush_all routine from the bdrv layer to the block-backend layer. In doing so, however, the semantics of the routine changed slightly such that flush_all now used blk_flush instead of bdrv_flush. blk_flush can fail if the attached device model reports that it is not "available," (i.e. the tray is open.) This changed the semantics of flush_all such that it can now fail for e.g. open CDROM drives. Reintroduce bdrv_flush_all to regain the old semantics without having to alter the behavior of blk_flush or blk_flush_all, which are already 'doing the right thing.' Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block/io: turn on dirty_bitmaps for the compressed writesPavel Butsykin1-9/+5
Previously was added the assert: commit 1755da16e32c15b22a521e8a38539e4b5cf367f3 Author: Paolo Bonzini <pbonzini@redhat.com> Date: Thu Oct 18 16:49:18 2012 +0200 block: introduce new dirty bitmap functionality Now the compressed write is always in coroutine and setting the bits is done after the write, so that we can return the dirty_bitmaps for the compressed writes. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: remove BlockDriver.bdrv_write_compressedPavel Butsykin1-31/+0
There are no block drivers left that implement the old .bdrv_write_compressed interface, so it can be removed. Also now we have no need to use the bdrv_pwrite_compressed function and we can remove it entirely. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block/io: reuse bdrv_co_pwritev() for write compressedPavel Butsykin1-16/+40
For bdrv_pwrite_compressed() it looks like most of the code creating coroutine is duplicated in bdrv_prwv_co(). So we can just add a flag (BDRV_REQ_WRITE_COMPRESSED) and use bdrv_prwv_co() as a generic one. In the end we get coroutine oriented function for write compressed by using bdrv_co_pwritev/blk_co_pwritev with BDRV_REQ_WRITE_COMPRESSED flag. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: Convert bdrv_pwrite_compressed() to BdrvChildPavel Butsykin1-1/+2
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Eric Blake <eblake@redhat.com> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: switch blk_write_compressed() to byte-based interfacePavel Butsykin1-15/+7
This is a preparatory patch, which continues the general trend of the transition to the byte-based interfaces. bdrv_check_request() and blk_check_request() are no longer used, thus we can remove them. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-08-18block: fix possible reorder of flush operationsDenis V. Lunev1-1/+2
This patch reduce CPU usage of flush operations a bit. When we have one flush completed we should kick only next operation. We should not start all pending operations in the hope that they will go back to wait on wait_queue. Also there is a technical possibility that requests will get reordered with the previous approach. After wakeup all requests are removed from the wait queue. They become active and they are processed one-by-one adding to the wait queue in the same order. Though new flush can arrive while all requests are not put into the queue. Signed-off-by: Denis V. Lunev <den@openvz.org> Tested-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Message-id: 1471457214-3994-3-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-18block: fix deadlock in bdrv_co_flushEvgeny Yakovlev1-2/+3
The following commit commit 3ff2f67a7c24183fcbcfe1332e5223ac6f96438c Author: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Date: Mon Jul 18 22:39:52 2016 +0300 block: ignore flush requests when storage is clean has introduced a regression. There is a problem that it is still possible for 2 requests to execute in non sequential fashion and sometimes this results in a deadlock when bdrv_drain_one/all are called for BDS with such stalled requests. 1. Current flushed_gen and flush_started_gen is 1. 2. Request 1 enters bdrv_co_flush to with write_gen 1 (i.e. the same as flushed_gen). It gets past flushed_gen != flush_started_gen and sets flush_started_gen to 1 (again, the same it was before). 3. Request 1 yields somewhere before exiting bdrv_co_flush 4. Request 2 enters bdrv_co_flush with write_gen 2. It gets past flushed_gen != flush_started_gen and sets flush_started_gen to 2. 5. Request 2 runs to completion and sets flushed_gen to 2 6. Request 1 is resumed, runs to completion and sets flushed_gen to 1. However flush_started_gen is now 2. From here on out flushed_gen is always != to flush_started_gen and all further requests will wait on flush_queue. This change replaces flush_started_gen with an explicitly tracked active flush request. Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Message-id: 1471457214-3994-2-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-03block: Cater to iscsi with non-power-of-2 discardEric Blake1-6/+9
Dell Equallogic iSCSI SANs have a very unusual advertised geometry: $ iscsi-inq -e 1 -c $((0xb0)) iscsi://XXX/0 wsnz:0 maximum compare and write length:1 optimal transfer length granularity:0 maximum transfer length:0 optimal transfer length:0 maximum prefetch xdread xdwrite transfer length:0 maximum unmap lba count:30720 maximum unmap block descriptor count:2 optimal unmap granularity:30720 ugavalid:1 unmap granularity alignment:0 maximum write same length:30720 which says that both the maximum and the optimal discard size is 15M. It is not immediately apparent if the device allows discard requests not aligned to the optimal size, nor if it allows discards at a finer granularity than the optimal size. I tried to find details in the SCSI Commands Reference Manual Rev. A on what valid values of maximum and optimal sizes are permitted, but while that document mentions a "Block Limits VPD Page", I couldn't actually find documentation of that page or what values it would have, or if a SCSI device has an advertisement of its minimal unmap granularity. So it is not obvious to me whether the Dell Equallogic device is compliance with the SCSI specification. Fortunately, it is easy enough to support non-power-of-2 sizing, even if it means we are less efficient than truly possible when targetting that device (for example, it means that we refuse to unmap anything that is not a multiple of 15M and aligned to a 15M boundary, even if the device truly does support a smaller granularity where unmapping actually works). Reported-by: Peter Lieven <pl@kamp.de> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1469129688-22848-5-git-send-email-eblake@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-20block: Kill .bdrv_co_discard()Eric Blake1-7/+2
Now that all drivers have a byte-based .bdrv_co_pdiscard(), we no longer need to worry about the sector-based version. We can also relax our minimum alignment to 1 for drivers that support it. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-18-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Add .bdrv_co_pdiscard() driver callbackEric Blake1-2/+5
There's enough drivers with a sector-based callback that it will be easier to switch one at a time. This patch adds a byte-based callback, and then after all drivers are swapped, we'll drop the sector-based callback. [checkpatch doesn't like the space after coroutine_fn in block_int.h, but it's consistent with the rest of the file] Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-10-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert .bdrv_aio_discard() to byte-basedEric Blake1-4/+3
Another step towards byte-based interfaces everywhere. Replace the sector-based driver callback .bdrv_aio_discard() with a new byte-based .bdrv_aio_pdiscard(). Only raw-posix and RBD drivers are affected, so it was not worth splitting into multiple patches. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-9-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_aio_discard() to byte-basedEric Blake1-8/+7
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_aio_discard() with a new byte-based bdrv_aio_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468624988-423-5-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Switch BlockRequest to byte-basedEric Blake1-32/+30
BlockRequest is the internal struct used by bdrv_aio_*. At the moment, all such calls were sector-based, but we will eventually convert to byte-based; start by changing the internal variables to be byte-based. No change to behavior, although the read and write code can now go byte-based through more of the stack. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468624988-423-4-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_discard() to byte-basedEric Blake1-10/+9
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_discard() with a new byte-based bdrv_pdiscard(), which silently ignores any unaligned head or tail. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-3-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_co_discard() to byte-basedEric Blake1-32/+35
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_co_discard() with a new byte-based bdrv_co_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. By calculating the alignment outside of the loop, and clamping the max discard to an aligned value, we can simplify the actions done within the loop. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-2-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Fragment writes to max transfer lengthEric Blake1-2/+33
Drivers should be able to rely on the block layer honoring the max transfer length, rather than needing to return -EINVAL (iscsi) or manually fragment things (nbd). We already fragment write zeroes at the block layer; this patch adds the fragmentation for normal writes, after requests have been aligned (fragmenting before alignment would lead to multiple unaligned requests, rather than just the head and tail). When fragmenting a large request where FUA was requested, but where we know that FUA is implemented by flushing all requests rather than the given request, then we can still get by with only one flush. Note, however, that we need a followup patch to the raw format driver to avoid a regression in the number of flushes actually issued. The return value was previously nebulous on success (sometimes zero, sometimes the length written); since we never have a short write, and since fragmenting may store yet another positive value in 'ret', change the function to always return 0 on success, matching what we do in bdrv_aligned_preadv(). Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468607524-19021-4-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Fragment reads to max transfer lengthEric Blake1-20/+33
Drivers should be able to rely on the block layer honoring the max transfer length, rather than needing to return -EINVAL (iscsi) or manually fragment things (nbd). This patch adds the fragmentation in the block layer, after requests have been aligned (fragmenting before alignment would lead to multiple unaligned requests, rather than just the head and tail). The return value was previously nebulous on success on whether it was zero or the length read; and fragmenting may introduce yet other non-zero values if we use the last length read. But as at least some callers are sloppy and expect only zero on success, it is easiest to just guarantee 0. [Fix uninitialized ret local variable in bdrv_aligned_preadv(). --Stefan] Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468607524-19021-2-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-18block: ignore flush requests when storage is cleanEvgeny Yakovlev1-0/+21
Some guests (win2008 server for example) do a lot of unnecessary flushing when underlying media has not changed. This adds additional overhead on host when calling fsync/fdatasync. This change introduces a write generation scheme in BlockDriverState. Current write generation is checked against last flushed generation to avoid unnessesary flushes. The problem with excessive flushing was found by a performance test which does parallel directory tree creation (from 2 processes). Results improved from 0.424 loops/sec to 0.432 loops/sec. Each loop creates 10^3 directories with 10 files in each. This affected some blkdebug testcases that were expecting error logs from failure-injected flushes which are now skipped entirely (tests 026 071 089). This also affects the performance of block jobs and thus BLOCK_JOB_READY events for driver-mirror and active block-commit commands now arrives faster, before QMP send successfully returns to caller (tests 141 144). Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1468870792-7411-5-git-send-email-den@openvz.org CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> CC: John Snow <jsnow@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini1-22/+23
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Convert bdrv_co_preadv/pwritev to BdrvChildKevin Wolf1-12/+13
This is the final patch for converting the common I/O path to take a BdrvChild parameter instead of BlockDriverState. The completion of this conversion means that all users that perform I/O on an image need to actually hold a reference (in the form of BdrvChild, possible as part of a BlockBackend) to that image. This also protects against inconsistent use of BlockBackend vs. BlockDriverState functions because direct use of a BlockDriverState isn't possible any more and blk->root is private for block-backends.c. In addition, we can now distinguish different users in the I/O path, and the future op blockers work is going to add assertions based on permissions stored in BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_prwv_co() to BdrvChildKevin Wolf1-20/+25
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pwrite_zeroes() to BdrvChildKevin Wolf1-4/+5
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pwrite(v/_sync) to BdrvChildKevin Wolf1-9/+8
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
generated by cgit v1.1 at 2024-12-29 06:11:11 +0000