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2017-06-26block: use BDRV_POLL_WHILE() in bdrv_rw_vmstate()Stefan Hajnoczi1-3/+1
Calling aio_poll() directly may have been fine previously, but this is the future, man! The difference between an aio_poll() loop and BDRV_POLL_WHILE() is that BDRV_POLL_WHILE() releases the AioContext around aio_poll(). This allows the IOThread to run fd handlers or BHs to complete the request. Failure to release the AioContext causes deadlocks. Using BDRV_POLL_WHILE() partially fixes a 'savevm' hang with -object iothread. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-06-26block: count bdrv_co_rw_vmstate() requestsStefan Hajnoczi1-5/+12
Call bdrv_inc/dec_in_flight() for vmstate reads/writes. This seems unnecessary at first glance because vmstate reads/writes are done synchronously while the guest is stopped. But we need the bdrv_wakeup() in bdrv_dec_in_flight() so the main loop sees request completion. Besides, it's cleaner to count vmstate reads/writes like ordinary read/write requests. The bdrv_wakeup() partially fixes a 'savevm' hang with -object iothread. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-06-16block: protect tracked_requests and flush_queue with reqs_lockPaolo Bonzini1-2/+14
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-14-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: access write_gen with atomicsPaolo Bonzini1-3/+3
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-13-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: use Stat64 for wr_highest_offsetPaolo Bonzini1-3/+1
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-12-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: access io_plugged with atomic opsPaolo Bonzini1-2/+2
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-7-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: access wakeup with atomic opsPaolo Bonzini1-1/+2
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-6-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: access serialising_in_flight with atomic opsPaolo Bonzini1-3/+3
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-5-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: access quiesce_counter with atomic opsPaolo Bonzini1-2/+2
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-3-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: access copy_on_read with atomic opsPaolo Bonzini1-4/+4
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-2-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-05-24blockjob: introduce block_job_pause/resume_allPaolo Bonzini1-16/+3
Remove use of block_job_pause/resume from outside blockjob.c, thus making them static. The new functions are used by the block layer, so place them in blockjob_int.h. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20170508141310.8674-5-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-12block: Simplify BDRV_BLOCK_RAW recursionEric Blake1-2/+2
Since we are already in coroutine context during the body of bdrv_co_get_block_status(), we can shave off a few layers of wrappers when recursing to query the protocol when a format driver returned BDRV_BLOCK_RAW. Note that we are already using the correct recursion later on in the same function, when probing whether the protocol layer is sparse in order to find out if we can add BDRV_BLOCK_ZERO to an existing BDRV_BLOCK_DATA|BDRV_BLOCK_OFFSET_VALID. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170504173745.27414-1-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-04-27block: fix alignment calculations in bdrv_co_do_zero_pwritevDenis V. Lunev1-1/+1
tail_padding_bytes is calculated wrong. F.e. for offset = 0 bytes = 2048 align = 512 we will have tail_padding_bytes = 512 which is definitely wrong. The patch fixes that arithmetics. Fortunately this problem is harmless, we will have 1 extra allocation and free thus there is no need to put this into stable. The problem is here from the very beginning. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-27block: Remove NULL check in bdrv_co_flushFam Zheng1-1/+1
Reported by Coverity. We already use bs in bdrv_inc_in_flight before checking for NULL. It is unnecessary as all callers pass non-NULL bs, so drop it. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-27Revert "block/io: Comment out permission assertions"Max Reitz1-10/+2
This reverts commit e3e0003a8f6570aba1421ef99a0b383a43371a74. This commit was necessary for the 2.9 release because we were unable to fix the underlying issue(s) in time. However, we will be for 2.10. Signed-off-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-18block: Walk bs->children carefully in bdrv_drain_recurseFam Zheng1-3/+20
The recursive bdrv_drain_recurse may run a block job completion BH that drops nodes. The coming changes will make that more likely and use-after-free would happen without this patch Stash the bs pointer and use bdrv_ref/bdrv_unref in addition to QLIST_FOREACH_SAFE to prevent such a case from happening. Since bdrv_unref accesses global state that is not protected by the AioContext lock, we cannot use bdrv_ref/bdrv_unref unconditionally. Fortunately the protection is not needed in IOThread because only main loop can modify a graph with the AioContext lock held. Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170418143044.12187-2-famz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Tested-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-04-11block/io: Comment out permission assertionsMax Reitz1-2/+10
In case of block migration, there may be writes to BlockBackends that do not have the write permission taken. Before this issue is fixed (which is not going to happen in 2.9), we therefore cannot assert that this is the case. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Kevin Wolf <kwolf@redhat.com> Message-id: 20170411145050.31290-1-mreitz@redhat.com Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-04-11block: Fix bdrv_co_flush early returnFam Zheng1-5/+7
bdrv_inc_in_flight and bdrv_dec_in_flight are mandatory for BDRV_POLL_WHILE to work, even for the shortcut case where flush is unnecessary. Move the if block to below bdrv_dec_in_flight, and BTW fix the variable declaration position. Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-11block: Use bdrv_coroutine_enter to start I/O coroutinesFam Zheng1-7/+7
BDRV_POLL_WHILE waits for the started I/O by releasing bs's ctx then polling the main context, which relies on the yielded coroutine continuing on bs->ctx before notifying qemu_aio_context with bdrv_wakeup(). Thus, using qemu_coroutine_enter to start I/O is wrong because if the coroutine is entered from main loop, co->ctx will be qemu_aio_context, as a result of the "release, poll, acquire" loop of BDRV_POLL_WHILE, race conditions happen when both main thread and the iothread access the same BDS: main loop iothread ----------------------------------------------------------------------- blockdev_snapshot aio_context_acquire(bs->ctx) virtio_scsi_data_plane_handle_cmd bdrv_drained_begin(bs->ctx) bdrv_flush(bs) bdrv_co_flush(bs) aio_context_acquire(bs->ctx).enter ... qemu_coroutine_yield(co) BDRV_POLL_WHILE() aio_context_release(bs->ctx) aio_context_acquire(bs->ctx).return ... aio_co_wake(co) aio_poll(qemu_aio_context) ... co_schedule_bh_cb() ... qemu_coroutine_enter(co) ... /* (A) bdrv_co_flush(bs) /* (B) I/O on bs */ continues... */ aio_context_release(bs->ctx) aio_context_acquire(bs->ctx) Note that in above case, bdrv_drained_begin() doesn't do the "release, poll, acquire" in BDRV_POLL_WHILE, because bs->in_flight == 0. Fix this by using bdrv_coroutine_enter and enter coroutine in the right context. iotests 109 output is updated because the coroutine reenter flow during mirror job complete is different (now through co_queue_wakeup, instead of the unconditional qemu_coroutine_switch before), making the end job len different. Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
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>
generated by cgit v1.1 at 2025-01-04 03:16:00 +0000