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qemu/tests/unit/test-block-iothread.c

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block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
/*
* Block tests for iothreads
*
* Copyright (c) 2018 Kevin Wolf <kwolf@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "block/block.h"
#include "block/blockjob_int.h"
#include "sysemu/block-backend.h"
#include "qapi/error.h"
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
#include "qapi/qmp/qdict.h"
Include qemu/main-loop.h less In my "build everything" tree, changing qemu/main-loop.h triggers a recompile of some 5600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). It includes block/aio.h, which in turn includes qemu/event_notifier.h, qemu/notify.h, qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h, qemu/thread.h, qemu/timer.h, and a few more. Include qemu/main-loop.h only where it's needed. Touching it now recompiles only some 1700 objects. For block/aio.h and qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the others, they shrink only slightly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-21-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-12 08:23:50 +03:00
#include "qemu/main-loop.h"
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
#include "iothread.h"
block: use int64_t instead of uint64_t in driver read handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix typos] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-03 13:27:59 +03:00
static int coroutine_fn bdrv_test_co_preadv(BlockDriverState *bs,
int64_t offset, int64_t bytes,
QEMUIOVector *qiov,
BdrvRequestFlags flags)
{
return 0;
}
static int coroutine_fn bdrv_test_co_pwritev(BlockDriverState *bs,
block: use int64_t instead of uint64_t in driver write handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver write handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_pwritev\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_pwritev() and bdrv_driver_pwritev_compressed() in block/io.c, both pass int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_save_vmstate() does bdrv_check_qiov_request(). Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_pwritev\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done shows several callers: qcow2: qcow2_co_truncate() write at most up to @offset, which is checked in generic qcow2_co_truncate() by bdrv_check_request(). qcow2_co_pwritev_compressed_task() pass the request (or part of the request) that already went through normal write path, so it should be OK qcow: qcow_co_pwritev_compressed() pass int64_t, it's updated by this patch quorum: quorum_co_pwrite_zeroes() pass int64_t and int - OK throttle: throttle_co_pwritev_compressed() pass int64_t, it's updated by this patch vmdk: vmdk_co_pwritev_compressed() pass int64_t, it's updated by this patch Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-03 13:28:00 +03:00
int64_t offset, int64_t bytes,
block: use int64_t instead of uint64_t in driver read handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix typos] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-03 13:27:59 +03:00
QEMUIOVector *qiov,
block: use int64_t instead of uint64_t in driver write handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver write handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_pwritev\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_pwritev() and bdrv_driver_pwritev_compressed() in block/io.c, both pass int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_save_vmstate() does bdrv_check_qiov_request(). Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_pwritev\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done shows several callers: qcow2: qcow2_co_truncate() write at most up to @offset, which is checked in generic qcow2_co_truncate() by bdrv_check_request(). qcow2_co_pwritev_compressed_task() pass the request (or part of the request) that already went through normal write path, so it should be OK qcow: qcow_co_pwritev_compressed() pass int64_t, it's updated by this patch quorum: quorum_co_pwrite_zeroes() pass int64_t and int - OK throttle: throttle_co_pwritev_compressed() pass int64_t, it's updated by this patch vmdk: vmdk_co_pwritev_compressed() pass int64_t, it's updated by this patch Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-03 13:28:00 +03:00
BdrvRequestFlags flags)
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
{
return 0;
}
static int coroutine_fn bdrv_test_co_pdiscard(BlockDriverState *bs,
block: use int64_t instead of int in driver discard handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver discard handlers bytes parameter to int64_t. The only caller of all updated function is bdrv_co_pdiscard in block/io.c. It is already prepared to work with 64bit requests, but pass at most max(bs->bl.max_pdiscard, INT_MAX) to the driver. Let's look at all updated functions: blkdebug: all calculations are still OK, thanks to bdrv_check_qiov_request(). both rule_check and bdrv_co_pdiscard are 64bit blklogwrites: pass to blk_loc_writes_co_log which is 64bit blkreplay, copy-on-read, filter-compress: pass to bdrv_co_pdiscard, OK copy-before-write: pass to bdrv_co_pdiscard which is 64bit and to cbw_do_copy_before_write which is 64bit file-posix: one handler calls raw_account_discard() is 64bit and both handlers calls raw_do_pdiscard(). Update raw_do_pdiscard, which pass to RawPosixAIOData::aio_nbytes, which is 64bit (and calls raw_account_discard()) gluster: somehow, third argument of glfs_discard_async is size_t. Let's set max_pdiscard accordingly. iscsi: iscsi_allocmap_set_invalid is 64bit, !is_byte_request_lun_aligned is 64bit. list.num is uint32_t. Let's clarify max_pdiscard and pdiscard_alignment. mirror_top: pass to bdrv_mirror_top_do_write() which is 64bit nbd: protocol limitation. max_pdiscard is alredy set strict enough, keep it as is for now. nvme: buf.nlb is uint32_t and we do shift. So, add corresponding limits to nvme_refresh_limits(). preallocate: pass to bdrv_co_pdiscard() which is 64bit. rbd: pass to qemu_rbd_start_co() which is 64bit. qcow2: calculations are still OK, thanks to bdrv_check_qiov_request(), qcow2_cluster_discard() is 64bit. raw-format: raw_adjust_offset() is 64bit, bdrv_co_pdiscard too. throttle: pass to bdrv_co_pdiscard() which is 64bit and to throttle_group_co_io_limits_intercept() which is 64bit as well. test-block-iothread: bytes argument is unused Great! Now all drivers are prepared to handle 64bit discard requests, or else have explicit max_pdiscard limits. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-11-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-03 13:28:06 +03:00
int64_t offset, int64_t bytes)
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
{
return 0;
}
static int coroutine_fn
block: Add @exact parameter to bdrv_co_truncate() We have two drivers (iscsi and file-posix) that (in some cases) return success from their .bdrv_co_truncate() implementation if the block device is larger than the requested offset, but cannot be shrunk. Some callers do not want that behavior, so this patch adds a new parameter that they can use to turn off that behavior. This patch just adds the parameter and lets the block/io.c and block/block-backend.c functions pass it around. All other callers always pass false and none of the implementations evaluate it, so that this patch does not change existing behavior. Future patches take care of that. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190918095144.955-5-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-18 12:51:40 +03:00
bdrv_test_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
block: Add flags to BlockDriver.bdrv_co_truncate() This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate() driver callbacks, and a supported_truncate_flags field in BlockDriverState that allows drivers to advertise support for request flags in the context of truncate. For now, we always pass 0 and no drivers declare support for any flag. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-2-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-24 15:54:39 +03:00
PreallocMode prealloc, BdrvRequestFlags flags,
Error **errp)
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
{
return 0;
}
static int coroutine_fn bdrv_test_co_block_status(BlockDriverState *bs,
bool want_zero,
int64_t offset, int64_t count,
int64_t *pnum, int64_t *map,
BlockDriverState **file)
{
*pnum = count;
return 0;
}
static BlockDriver bdrv_test = {
.format_name = "test",
.instance_size = 1,
block: use int64_t instead of uint64_t in driver read handlers We are generally moving to int64_t for both offset and bytes parameters on all io paths. Main motivation is realization of 64-bit write_zeroes operation for fast zeroing large disk chunks, up to the whole disk. We chose signed type, to be consistent with off_t (which is signed) and with possibility for signed return type (where negative value means error). So, convert driver read handlers parameters which are already 64bit to signed type. While being here, convert also flags parameter to be BdrvRequestFlags. Now let's consider all callers. Simple git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?' shows that's there three callers of driver function: bdrv_driver_preadv() in block/io.c, passes int64_t, checked by bdrv_check_qiov_request() to be non-negative. qcow2_load_vmstate() does bdrv_check_qiov_request(). do_perform_cow_read() has uint64_t argument. And a lot of things in qcow2 driver are uint64_t, so converting it is big job. But we must not work with requests that don't satisfy bdrv_check_qiov_request(), so let's just assert it here. Still, the functions may be called directly, not only by drv->... Let's check: git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \ awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \ while read func; do git grep "$func(" | \ grep -v "$func(BlockDriverState"; done The only one such caller: QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1); ... ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0); in tests/unit/test-bdrv-drain.c, and it's OK obviously. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: fix typos] Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-03 13:27:59 +03:00
.bdrv_co_preadv = bdrv_test_co_preadv,
.bdrv_co_pwritev = bdrv_test_co_pwritev,
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
.bdrv_co_pdiscard = bdrv_test_co_pdiscard,
.bdrv_co_truncate = bdrv_test_co_truncate,
.bdrv_co_block_status = bdrv_test_co_block_status,
};
static void test_sync_op_pread(BdrvChild *c)
{
uint8_t buf[512];
int ret;
/* Success */
block: Change bdrv_{pread,pwrite,pwrite_sync}() param order Swap 'buf' and 'bytes' around for consistency with bdrv_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pread(child, offset, buf, bytes, flags) + bdrv_pread(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite(child, offset, buf, bytes, flags) + bdrv_pwrite(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite_sync(child, offset, buf, bytes, flags) + bdrv_pwrite_sync(child, offset, bytes, buf, flags) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-3-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-06-09 18:27:36 +03:00
ret = bdrv_pread(c, 0, sizeof(buf), buf, 0);
block: Make bdrv_{pread,pwrite}() return 0 on success They currently return the value of their 'bytes' parameter on success. Make them return 0 instead, for consistency with other I/O functions and in preparation to implement them using generated_co_wrapper. This also makes it clear that short reads/writes are not possible. The few callers that rely on the previous behavior are adjusted accordingly by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220609152744.3891847-4-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-06-09 18:27:37 +03:00
g_assert_cmpint(ret, ==, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
/* Early error: Negative offset */
block: Change bdrv_{pread,pwrite,pwrite_sync}() param order Swap 'buf' and 'bytes' around for consistency with bdrv_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pread(child, offset, buf, bytes, flags) + bdrv_pread(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite(child, offset, buf, bytes, flags) + bdrv_pwrite(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite_sync(child, offset, buf, bytes, flags) + bdrv_pwrite_sync(child, offset, bytes, buf, flags) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-3-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-06-09 18:27:36 +03:00
ret = bdrv_pread(c, -2, sizeof(buf), buf, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, -EIO);
}
static void test_sync_op_pwrite(BdrvChild *c)
{
tests/unit/test-block-iothread: fix maybe-uninitialized error on GCC 11 When building qemu with GCC 11, test-block-iothread produces the following warning: ../tests/unit/test-block-iothread.c:148:11: error: ‘buf’ may be used uninitialized [-Werror=maybe-uninitialized] This is caused by buf[512] left uninitialized and passed to bdrv_save_vmstate() that expects a const uint8_t *, so the compiler assumes it will be read and expects the parameter to be initialized. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210319112218.49609-1-eesposit@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-03-19 14:22:18 +03:00
uint8_t buf[512] = { 0 };
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
int ret;
/* Success */
block: Change bdrv_{pread,pwrite,pwrite_sync}() param order Swap 'buf' and 'bytes' around for consistency with bdrv_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pread(child, offset, buf, bytes, flags) + bdrv_pread(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite(child, offset, buf, bytes, flags) + bdrv_pwrite(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite_sync(child, offset, buf, bytes, flags) + bdrv_pwrite_sync(child, offset, bytes, buf, flags) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-3-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-06-09 18:27:36 +03:00
ret = bdrv_pwrite(c, 0, sizeof(buf), buf, 0);
block: Make bdrv_{pread,pwrite}() return 0 on success They currently return the value of their 'bytes' parameter on success. Make them return 0 instead, for consistency with other I/O functions and in preparation to implement them using generated_co_wrapper. This also makes it clear that short reads/writes are not possible. The few callers that rely on the previous behavior are adjusted accordingly by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220609152744.3891847-4-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-06-09 18:27:37 +03:00
g_assert_cmpint(ret, ==, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
/* Early error: Negative offset */
block: Change bdrv_{pread,pwrite,pwrite_sync}() param order Swap 'buf' and 'bytes' around for consistency with bdrv_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pread(child, offset, buf, bytes, flags) + bdrv_pread(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite(child, offset, buf, bytes, flags) + bdrv_pwrite(child, offset, bytes, buf, flags) @@ expression child, offset, buf, bytes, flags; @@ - bdrv_pwrite_sync(child, offset, buf, bytes, flags) + bdrv_pwrite_sync(child, offset, bytes, buf, flags) Resulting overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220609152744.3891847-3-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-06-09 18:27:36 +03:00
ret = bdrv_pwrite(c, -2, sizeof(buf), buf, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, -EIO);
}
static void test_sync_op_blk_pread(BlockBackend *blk)
{
uint8_t buf[512];
int ret;
/* Success */
block: Change blk_{pread,pwrite}() param order Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:11 +03:00
ret = blk_pread(blk, 0, sizeof(buf), buf, 0);
block: Make blk_{pread,pwrite}() return 0 on success They currently return the value of their 'bytes' parameter on success. Make them return 0 instead, for consistency with other I/O functions and in preparation to implement them using generated_co_wrapper. This also makes it clear that short reads/writes are not possible. Signed-off-by: Alberto Faria <afaria@redhat.com> Message-Id: <20220705161527.1054072-2-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:09 +03:00
g_assert_cmpint(ret, ==, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
/* Early error: Negative offset */
block: Change blk_{pread,pwrite}() param order Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:11 +03:00
ret = blk_pread(blk, -2, sizeof(buf), buf, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, -EIO);
}
static void test_sync_op_blk_pwrite(BlockBackend *blk)
{
tests/unit/test-block-iothread: fix maybe-uninitialized error on GCC 11 When building qemu with GCC 11, test-block-iothread produces the following warning: ../tests/unit/test-block-iothread.c:148:11: error: ‘buf’ may be used uninitialized [-Werror=maybe-uninitialized] This is caused by buf[512] left uninitialized and passed to bdrv_save_vmstate() that expects a const uint8_t *, so the compiler assumes it will be read and expects the parameter to be initialized. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210319112218.49609-1-eesposit@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-03-19 14:22:18 +03:00
uint8_t buf[512] = { 0 };
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
int ret;
/* Success */
block: Change blk_{pread,pwrite}() param order Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:11 +03:00
ret = blk_pwrite(blk, 0, sizeof(buf), buf, 0);
block: Make blk_{pread,pwrite}() return 0 on success They currently return the value of their 'bytes' parameter on success. Make them return 0 instead, for consistency with other I/O functions and in preparation to implement them using generated_co_wrapper. This also makes it clear that short reads/writes are not possible. Signed-off-by: Alberto Faria <afaria@redhat.com> Message-Id: <20220705161527.1054072-2-afaria@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:09 +03:00
g_assert_cmpint(ret, ==, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
/* Early error: Negative offset */
block: Change blk_{pread,pwrite}() param order Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:11 +03:00
ret = blk_pwrite(blk, -2, sizeof(buf), buf, 0);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, -EIO);
}
block: Add blk_{preadv,pwritev}() Implement them using generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-8-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:15 +03:00
static void test_sync_op_blk_preadv(BlockBackend *blk)
{
uint8_t buf[512];
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, sizeof(buf));
int ret;
/* Success */
ret = blk_preadv(blk, 0, sizeof(buf), &qiov, 0);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_preadv(blk, -2, sizeof(buf), &qiov, 0);
g_assert_cmpint(ret, ==, -EIO);
}
static void test_sync_op_blk_pwritev(BlockBackend *blk)
{
uint8_t buf[512] = { 0 };
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, sizeof(buf));
int ret;
/* Success */
ret = blk_pwritev(blk, 0, sizeof(buf), &qiov, 0);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_pwritev(blk, -2, sizeof(buf), &qiov, 0);
g_assert_cmpint(ret, ==, -EIO);
}
block: Add blk_[co_]preadv_part() Implement blk_preadv_part() using generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-9-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:16 +03:00
static void test_sync_op_blk_preadv_part(BlockBackend *blk)
{
uint8_t buf[512];
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, sizeof(buf));
int ret;
/* Success */
ret = blk_preadv_part(blk, 0, sizeof(buf), &qiov, 0, 0);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_preadv_part(blk, -2, sizeof(buf), &qiov, 0, 0);
g_assert_cmpint(ret, ==, -EIO);
}
block: Export blk_pwritev_part() in block-backend-io.h Also convert it into a generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-10-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:17 +03:00
static void test_sync_op_blk_pwritev_part(BlockBackend *blk)
{
uint8_t buf[512] = { 0 };
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, sizeof(buf));
int ret;
/* Success */
ret = blk_pwritev_part(blk, 0, sizeof(buf), &qiov, 0, 0);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_pwritev_part(blk, -2, sizeof(buf), &qiov, 0, 0);
g_assert_cmpint(ret, ==, -EIO);
}
block: Add blk_co_pwrite_compressed() Also convert blk_pwrite_compressed() into a generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-12-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:19 +03:00
static void test_sync_op_blk_pwrite_compressed(BlockBackend *blk)
{
uint8_t buf[512] = { 0 };
int ret;
/* Late error: Not supported */
ret = blk_pwrite_compressed(blk, 0, sizeof(buf), buf);
g_assert_cmpint(ret, ==, -ENOTSUP);
/* Early error: Negative offset */
ret = blk_pwrite_compressed(blk, -2, sizeof(buf), buf);
g_assert_cmpint(ret, ==, -EIO);
}
block: Implement blk_pwrite_zeroes() using generated_co_wrapper Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-13-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:20 +03:00
static void test_sync_op_blk_pwrite_zeroes(BlockBackend *blk)
{
int ret;
/* Success */
ret = blk_pwrite_zeroes(blk, 0, 512, 0);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_pwrite_zeroes(blk, -2, 512, 0);
g_assert_cmpint(ret, ==, -EIO);
}
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
static void test_sync_op_load_vmstate(BdrvChild *c)
{
uint8_t buf[512];
int ret;
/* Error: Driver does not support snapshots */
ret = bdrv_load_vmstate(c->bs, buf, 0, sizeof(buf));
g_assert_cmpint(ret, ==, -ENOTSUP);
}
static void test_sync_op_save_vmstate(BdrvChild *c)
{
tests/unit/test-block-iothread: fix maybe-uninitialized error on GCC 11 When building qemu with GCC 11, test-block-iothread produces the following warning: ../tests/unit/test-block-iothread.c:148:11: error: ‘buf’ may be used uninitialized [-Werror=maybe-uninitialized] This is caused by buf[512] left uninitialized and passed to bdrv_save_vmstate() that expects a const uint8_t *, so the compiler assumes it will be read and expects the parameter to be initialized. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210319112218.49609-1-eesposit@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-03-19 14:22:18 +03:00
uint8_t buf[512] = { 0 };
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
int ret;
/* Error: Driver does not support snapshots */
ret = bdrv_save_vmstate(c->bs, buf, 0, sizeof(buf));
g_assert_cmpint(ret, ==, -ENOTSUP);
}
static void test_sync_op_pdiscard(BdrvChild *c)
{
int ret;
/* Normal success path */
c->bs->open_flags |= BDRV_O_UNMAP;
ret = bdrv_pdiscard(c, 0, 512);
g_assert_cmpint(ret, ==, 0);
/* Early success: UNMAP not supported */
c->bs->open_flags &= ~BDRV_O_UNMAP;
ret = bdrv_pdiscard(c, 0, 512);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = bdrv_pdiscard(c, -2, 512);
g_assert_cmpint(ret, ==, -EIO);
}
static void test_sync_op_blk_pdiscard(BlockBackend *blk)
{
int ret;
/* Early success: UNMAP not supported */
ret = blk_pdiscard(blk, 0, 512);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_pdiscard(blk, -2, 512);
g_assert_cmpint(ret, ==, -EIO);
}
static void test_sync_op_truncate(BdrvChild *c)
{
int ret;
/* Normal success path */
block: Add flags to bdrv(_co)_truncate() Now that block drivers can support flags for .bdrv_co_truncate, expose the parameter in the node level interfaces bdrv_co_truncate() and bdrv_truncate(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-24 15:54:40 +03:00
ret = bdrv_truncate(c, 65536, false, PREALLOC_MODE_OFF, 0, NULL);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
block: Add flags to bdrv(_co)_truncate() Now that block drivers can support flags for .bdrv_co_truncate, expose the parameter in the node level interfaces bdrv_co_truncate() and bdrv_truncate(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-24 15:54:40 +03:00
ret = bdrv_truncate(c, -2, false, PREALLOC_MODE_OFF, 0, NULL);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, -EINVAL);
/* Error: Read-only image */
c->bs->open_flags &= ~BDRV_O_RDWR;
block: Add flags to bdrv(_co)_truncate() Now that block drivers can support flags for .bdrv_co_truncate, expose the parameter in the node level interfaces bdrv_co_truncate() and bdrv_truncate(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200424125448.63318-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-24 15:54:40 +03:00
ret = bdrv_truncate(c, 65536, false, PREALLOC_MODE_OFF, 0, NULL);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
g_assert_cmpint(ret, ==, -EACCES);
c->bs->open_flags |= BDRV_O_RDWR;
}
block: Add blk_co_truncate() Also convert blk_truncate() into a generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-17-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:24 +03:00
static void test_sync_op_blk_truncate(BlockBackend *blk)
{
int ret;
/* Normal success path */
ret = blk_truncate(blk, 65536, false, PREALLOC_MODE_OFF, 0, NULL);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = blk_truncate(blk, -2, false, PREALLOC_MODE_OFF, 0, NULL);
g_assert_cmpint(ret, ==, -EINVAL);
}
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
static void test_sync_op_block_status(BdrvChild *c)
{
int ret;
int64_t n;
/* Normal success path */
ret = bdrv_is_allocated(c->bs, 0, 65536, &n);
g_assert_cmpint(ret, ==, 0);
/* Early success: No driver support */
bdrv_test.bdrv_co_block_status = NULL;
ret = bdrv_is_allocated(c->bs, 0, 65536, &n);
g_assert_cmpint(ret, ==, 1);
/* Early success: bytes = 0 */
ret = bdrv_is_allocated(c->bs, 0, 0, &n);
g_assert_cmpint(ret, ==, 0);
/* Early success: Offset > image size*/
ret = bdrv_is_allocated(c->bs, 0x1000000, 0x1000000, &n);
g_assert_cmpint(ret, ==, 0);
}
static void test_sync_op_flush(BdrvChild *c)
{
int ret;
/* Normal success path */
ret = bdrv_flush(c->bs);
g_assert_cmpint(ret, ==, 0);
/* Early success: Read-only image */
c->bs->open_flags &= ~BDRV_O_RDWR;
ret = bdrv_flush(c->bs);
g_assert_cmpint(ret, ==, 0);
c->bs->open_flags |= BDRV_O_RDWR;
}
static void test_sync_op_blk_flush(BlockBackend *blk)
{
BlockDriverState *bs = blk_bs(blk);
int ret;
/* Normal success path */
ret = blk_flush(blk);
g_assert_cmpint(ret, ==, 0);
/* Early success: Read-only image */
bs->open_flags &= ~BDRV_O_RDWR;
ret = blk_flush(blk);
g_assert_cmpint(ret, ==, 0);
bs->open_flags |= BDRV_O_RDWR;
}
static void test_sync_op_check(BdrvChild *c)
{
BdrvCheckResult result;
int ret;
/* Error: Driver does not implement check */
ret = bdrv_check(c->bs, &result, 0);
g_assert_cmpint(ret, ==, -ENOTSUP);
}
block: rename bdrv_invalidate_cache_all, blk_invalidate_cache and test_sync_op_invalidate_cache Following the bdrv_activate renaming, change also the name of the respective callers. bdrv_invalidate_cache_all -> bdrv_activate_all blk_invalidate_cache -> blk_activate test_sync_op_invalidate_cache -> test_sync_op_activate No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220209105452.1694545-5-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-09 13:54:51 +03:00
static void test_sync_op_activate(BdrvChild *c)
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
{
/* Early success: Image is not inactive */
block: introduce bdrv_activate This function is currently just a wrapper for bdrv_invalidate_cache(), but in future will contain the code of bdrv_co_invalidate_cache() that has to always be protected by BQL, and leave the rest in the I/O coroutine. Replace all bdrv_invalidate_cache() invokations with bdrv_activate(). Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220209105452.1694545-4-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-09 13:54:50 +03:00
bdrv_activate(c->bs, NULL);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
}
typedef struct SyncOpTest {
const char *name;
void (*fn)(BdrvChild *c);
void (*blkfn)(BlockBackend *blk);
} SyncOpTest;
const SyncOpTest sync_op_tests[] = {
{
.name = "/sync-op/pread",
.fn = test_sync_op_pread,
.blkfn = test_sync_op_blk_pread,
}, {
.name = "/sync-op/pwrite",
.fn = test_sync_op_pwrite,
.blkfn = test_sync_op_blk_pwrite,
block: Add blk_{preadv,pwritev}() Implement them using generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-8-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:15 +03:00
}, {
.name = "/sync-op/preadv",
.fn = NULL,
.blkfn = test_sync_op_blk_preadv,
}, {
.name = "/sync-op/pwritev",
.fn = NULL,
.blkfn = test_sync_op_blk_pwritev,
block: Add blk_[co_]preadv_part() Implement blk_preadv_part() using generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-9-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:16 +03:00
}, {
.name = "/sync-op/preadv_part",
.fn = NULL,
.blkfn = test_sync_op_blk_preadv_part,
block: Export blk_pwritev_part() in block-backend-io.h Also convert it into a generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-10-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:17 +03:00
}, {
.name = "/sync-op/pwritev_part",
.fn = NULL,
.blkfn = test_sync_op_blk_pwritev_part,
block: Add blk_co_pwrite_compressed() Also convert blk_pwrite_compressed() into a generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-12-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:19 +03:00
}, {
.name = "/sync-op/pwrite_compressed",
.fn = NULL,
.blkfn = test_sync_op_blk_pwrite_compressed,
block: Implement blk_pwrite_zeroes() using generated_co_wrapper Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-13-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:20 +03:00
}, {
.name = "/sync-op/pwrite_zeroes",
.fn = NULL,
.blkfn = test_sync_op_blk_pwrite_zeroes,
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
}, {
.name = "/sync-op/load_vmstate",
.fn = test_sync_op_load_vmstate,
}, {
.name = "/sync-op/save_vmstate",
.fn = test_sync_op_save_vmstate,
}, {
.name = "/sync-op/pdiscard",
.fn = test_sync_op_pdiscard,
.blkfn = test_sync_op_blk_pdiscard,
}, {
.name = "/sync-op/truncate",
.fn = test_sync_op_truncate,
block: Add blk_co_truncate() Also convert blk_truncate() into a generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-17-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:24 +03:00
.blkfn = test_sync_op_blk_truncate,
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
}, {
.name = "/sync-op/block_status",
.fn = test_sync_op_block_status,
}, {
.name = "/sync-op/flush",
.fn = test_sync_op_flush,
.blkfn = test_sync_op_blk_flush,
}, {
.name = "/sync-op/check",
.fn = test_sync_op_check,
}, {
block: rename bdrv_invalidate_cache_all, blk_invalidate_cache and test_sync_op_invalidate_cache Following the bdrv_activate renaming, change also the name of the respective callers. bdrv_invalidate_cache_all -> bdrv_activate_all blk_invalidate_cache -> blk_activate test_sync_op_invalidate_cache -> test_sync_op_activate No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220209105452.1694545-5-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-09 13:54:51 +03:00
.name = "/sync-op/activate",
.fn = test_sync_op_activate,
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
},
};
/* Test synchronous operations that run in a different iothread, so we have to
* poll for the coroutine there to return. */
static void test_sync_op(const void *opaque)
{
const SyncOpTest *t = opaque;
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
BlockBackend *blk;
BlockDriverState *bs;
BdrvChild *c;
block: Add BlockBackend.ctx This adds a new parameter to blk_new() which requires its callers to declare from which AioContext this BlockBackend is going to be used (or the locks of which AioContext need to be taken anyway). The given context is only stored and kept up to date when changing AioContexts. Actually applying the stored AioContext to the root node is saved for another commit. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-25 15:25:10 +03:00
blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
bs->total_sectors = 65536 / BDRV_SECTOR_SIZE;
blk_insert_bs(blk, bs, &error_abort);
c = QLIST_FIRST(&bs->parents);
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, ctx, &error_abort);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
aio_context_acquire(ctx);
block: Add blk_{preadv,pwritev}() Implement them using generated_co_wrapper. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-8-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-05 19:15:15 +03:00
if (t->fn) {
t->fn(c);
}
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
if (t->blkfn) {
t->blkfn(blk);
}
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_release(ctx);
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
bdrv_unref(bs);
blk_unref(blk);
}
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
typedef struct TestBlockJob {
BlockJob common;
bool should_complete;
int n;
} TestBlockJob;
static int test_job_prepare(Job *job)
{
g_assert(qemu_get_current_aio_context() == qemu_get_aio_context());
return 0;
}
static int coroutine_fn test_job_run(Job *job, Error **errp)
{
TestBlockJob *s = container_of(job, TestBlockJob, common.job);
job_transition_to_ready(&s->common.job);
while (!s->should_complete) {
s->n++;
g_assert(qemu_get_current_aio_context() == job->aio_context);
/* Avoid job_sleep_ns() because it marks the job as !busy. We want to
* emulate some actual activity (probably some I/O) here so that the
* drain involved in AioContext switches has to wait for this activity
* to stop. */
qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000);
job_pause_point(&s->common.job);
}
g_assert(qemu_get_current_aio_context() == job->aio_context);
return 0;
}
static void test_job_complete(Job *job, Error **errp)
{
TestBlockJob *s = container_of(job, TestBlockJob, common.job);
s->should_complete = true;
}
BlockJobDriver test_job_driver = {
.job_driver = {
.instance_size = sizeof(TestBlockJob),
.free = block_job_free,
.user_resume = block_job_user_resume,
.run = test_job_run,
.complete = test_job_complete,
.prepare = test_job_prepare,
},
};
static void test_attach_blockjob(void)
{
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
BlockBackend *blk;
BlockDriverState *bs;
TestBlockJob *tjob;
block: Add BlockBackend.ctx This adds a new parameter to blk_new() which requires its callers to declare from which AioContext this BlockBackend is going to be used (or the locks of which AioContext need to be taken anyway). The given context is only stored and kept up to date when changing AioContexts. Actually applying the stored AioContext to the root node is saved for another commit. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-25 15:25:10 +03:00
blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
blk_insert_bs(blk, bs, &error_abort);
tjob = block_job_create("job0", &test_job_driver, NULL, bs,
0, BLK_PERM_ALL,
0, 0, NULL, NULL, &error_abort);
job_start(&tjob->common.job);
while (tjob->n == 0) {
aio_poll(qemu_get_aio_context(), false);
}
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, ctx, &error_abort);
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
tjob->n = 0;
while (tjob->n == 0) {
aio_poll(qemu_get_aio_context(), false);
}
aio_context_acquire(ctx);
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
aio_context_release(ctx);
tjob->n = 0;
while (tjob->n == 0) {
aio_poll(qemu_get_aio_context(), false);
}
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, ctx, &error_abort);
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
tjob->n = 0;
while (tjob->n == 0) {
aio_poll(qemu_get_aio_context(), false);
}
jobs: use job locks also in the unit tests Add missing job synchronization in the unit tests, with explicit locks. We are deliberately using _locked functions wrapped by a guard instead of a normal call because the normal call will be removed in future, as the only usage is limited to the tests. In other words, if a function like job_pause() is/will be only used in tests to avoid: WITH_JOB_LOCK_GUARD(){ job_pause_locked(); } then it is not worth keeping job_pause(), and just use the guard. Note: at this stage, job_{lock/unlock} and job lock guard macros are *nop*. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20220926093214.506243-10-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-09-26 12:32:02 +03:00
WITH_JOB_LOCK_GUARD() {
job_complete_sync_locked(&tjob->common.job, &error_abort);
}
job.c: enable job lock/unlock and remove Aiocontext locks Change the job_{lock/unlock} and macros to use job_mutex. Now that they are not nop anymore, remove the aiocontext to avoid deadlocks. Therefore: - when possible, remove completely the aiocontext lock/unlock pair - if it is used by some other function too, reduce the locking section as much as possible, leaving the job API outside. - change AIO_WAIT_WHILE in AIO_WAIT_WHILE_UNLOCKED, since we are not using the aiocontext lock anymore The only functions that still need the aiocontext lock are: - the JobDriver callbacks, already documented in job.h - job_cancel_sync() in replication.c is called with aio_context_lock taken, but now job is using AIO_WAIT_WHILE_UNLOCKED so we need to release the lock. Reduce the locking section to only cover the callback invocation and document the functions that take the AioContext lock, to avoid taking it twice. Also remove real_job_{lock/unlock}, as they are replaced by the public functions. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220926093214.506243-19-eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-09-26 12:32:11 +03:00
aio_context_acquire(ctx);
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
aio_context_release(ctx);
bdrv_unref(bs);
blk_unref(blk);
}
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
/*
* Test that changing the AioContext for one node in a tree (here through blk)
* changes all other nodes as well:
*
* blk
* |
* | bs_verify [blkverify]
* | / \
* | / \
* bs_a [bdrv_test] bs_b [bdrv_test]
*
*/
static void test_propagate_basic(void)
{
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
AioContext *main_ctx;
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
BlockBackend *blk;
BlockDriverState *bs_a, *bs_b, *bs_verify;
QDict *options;
block: Use bdrv_default_perms() bdrv_default_perms() can decide which permission profile to use based on the BdrvChildRole, so block drivers do not need to select it explicitly. The blkverify driver now no longer shares the WRITE permission for the image to verify. We thus have to adjust two places in test-block-iothread not to take it. (Note that in theory, blkverify should behave like quorum in this regard and share neither WRITE nor RESIZE for both of its children. In practice, it does not really matter, because blkverify is used only for debugging, so we might as well keep its permissions rather liberal.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-30-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-13 14:05:39 +03:00
/*
* Create bs_a and its BlockBackend. We cannot take the RESIZE
* permission because blkverify will not share it on the test
* image.
*/
blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL & ~BLK_PERM_RESIZE,
BLK_PERM_ALL);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
bs_a = bdrv_new_open_driver(&bdrv_test, "bs_a", BDRV_O_RDWR, &error_abort);
blk_insert_bs(blk, bs_a, &error_abort);
/* Create bs_b */
bs_b = bdrv_new_open_driver(&bdrv_test, "bs_b", BDRV_O_RDWR, &error_abort);
/* Create blkverify filter that references both bs_a and bs_b */
options = qdict_new();
qdict_put_str(options, "driver", "blkverify");
qdict_put_str(options, "test", "bs_a");
qdict_put_str(options, "raw", "bs_b");
bs_verify = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
/* Switch the AioContext */
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, ctx, &error_abort);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs_a) == ctx);
g_assert(bdrv_get_aio_context(bs_verify) == ctx);
g_assert(bdrv_get_aio_context(bs_b) == ctx);
/* Switch the AioContext back */
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
main_ctx = qemu_get_aio_context();
aio_context_acquire(ctx);
blk_set_aio_context(blk, main_ctx, &error_abort);
aio_context_release(ctx);
g_assert(blk_get_aio_context(blk) == main_ctx);
g_assert(bdrv_get_aio_context(bs_a) == main_ctx);
g_assert(bdrv_get_aio_context(bs_verify) == main_ctx);
g_assert(bdrv_get_aio_context(bs_b) == main_ctx);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
bdrv_unref(bs_verify);
bdrv_unref(bs_b);
bdrv_unref(bs_a);
blk_unref(blk);
}
/*
* Test that diamonds in the graph don't lead to endless recursion:
*
* blk
* |
* bs_verify [blkverify]
* / \
* / \
* bs_b [raw] bs_c[raw]
* \ /
* \ /
* bs_a [bdrv_test]
*/
static void test_propagate_diamond(void)
{
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
AioContext *main_ctx;
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
BlockBackend *blk;
BlockDriverState *bs_a, *bs_b, *bs_c, *bs_verify;
QDict *options;
/* Create bs_a */
bs_a = bdrv_new_open_driver(&bdrv_test, "bs_a", BDRV_O_RDWR, &error_abort);
/* Create bs_b and bc_c */
options = qdict_new();
qdict_put_str(options, "driver", "raw");
qdict_put_str(options, "file", "bs_a");
qdict_put_str(options, "node-name", "bs_b");
bs_b = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
options = qdict_new();
qdict_put_str(options, "driver", "raw");
qdict_put_str(options, "file", "bs_a");
qdict_put_str(options, "node-name", "bs_c");
bs_c = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
/* Create blkverify filter that references both bs_b and bs_c */
options = qdict_new();
qdict_put_str(options, "driver", "blkverify");
qdict_put_str(options, "test", "bs_b");
qdict_put_str(options, "raw", "bs_c");
bs_verify = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
block: Use bdrv_default_perms() bdrv_default_perms() can decide which permission profile to use based on the BdrvChildRole, so block drivers do not need to select it explicitly. The blkverify driver now no longer shares the WRITE permission for the image to verify. We thus have to adjust two places in test-block-iothread not to take it. (Note that in theory, blkverify should behave like quorum in this regard and share neither WRITE nor RESIZE for both of its children. In practice, it does not really matter, because blkverify is used only for debugging, so we might as well keep its permissions rather liberal.) Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200513110544.176672-30-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-13 14:05:39 +03:00
/*
* Do not take the RESIZE permission: This would require the same
* from bs_c and thus from bs_a; however, blkverify will not share
* it on bs_b, and thus it will not be available for bs_a.
*/
blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL & ~BLK_PERM_RESIZE,
BLK_PERM_ALL);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
blk_insert_bs(blk, bs_verify, &error_abort);
/* Switch the AioContext */
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, ctx, &error_abort);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs_verify) == ctx);
g_assert(bdrv_get_aio_context(bs_a) == ctx);
g_assert(bdrv_get_aio_context(bs_b) == ctx);
g_assert(bdrv_get_aio_context(bs_c) == ctx);
/* Switch the AioContext back */
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
main_ctx = qemu_get_aio_context();
aio_context_acquire(ctx);
blk_set_aio_context(blk, main_ctx, &error_abort);
aio_context_release(ctx);
g_assert(blk_get_aio_context(blk) == main_ctx);
g_assert(bdrv_get_aio_context(bs_verify) == main_ctx);
g_assert(bdrv_get_aio_context(bs_a) == main_ctx);
g_assert(bdrv_get_aio_context(bs_b) == main_ctx);
g_assert(bdrv_get_aio_context(bs_c) == main_ctx);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
blk_unref(blk);
bdrv_unref(bs_verify);
bdrv_unref(bs_c);
bdrv_unref(bs_b);
bdrv_unref(bs_a);
}
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
static void test_propagate_mirror(void)
{
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
AioContext *main_ctx = qemu_get_aio_context();
test-block-iothread: Check filter node in test_propagate_mirror Just make the test cover the AioContext of the filter node as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-05-03 14:20:54 +03:00
BlockDriverState *src, *target, *filter;
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
BlockBackend *blk;
Job *job;
Error *local_err = NULL;
/* Create src and target*/
src = bdrv_new_open_driver(&bdrv_test, "src", BDRV_O_RDWR, &error_abort);
target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR,
&error_abort);
/* Start a mirror job */
mirror_start("job0", src, target, NULL, JOB_DEFAULT, 0, 0, 0,
mirror: Fix bdrv_has_zero_init() use bdrv_has_zero_init() only has meaning for newly created images or image areas. If the mirror job itself did not create the image, it cannot rely on bdrv_has_zero_init()'s result to carry any meaning. This is the case for drive-mirror with mode=existing and always for blockdev-mirror. Note that we only have to zero-initialize the target with sync=full, because other modes actually do not promise that the target will contain the same data as the source after the job -- sync=top only promises to copy anything allocated in the top layer, and sync=none will only copy new I/O. (Which is how mirror has always handled it.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190724171239.8764-3-mreitz@redhat.com Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-24 20:12:30 +03:00
MIRROR_SYNC_MODE_NONE, MIRROR_OPEN_BACKING_CHAIN, false,
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT,
false, "filter_node", MIRROR_COPY_MODE_BACKGROUND,
&error_abort);
jobs: use job locks also in the unit tests Add missing job synchronization in the unit tests, with explicit locks. We are deliberately using _locked functions wrapped by a guard instead of a normal call because the normal call will be removed in future, as the only usage is limited to the tests. In other words, if a function like job_pause() is/will be only used in tests to avoid: WITH_JOB_LOCK_GUARD(){ job_pause_locked(); } then it is not worth keeping job_pause(), and just use the guard. Note: at this stage, job_{lock/unlock} and job lock guard macros are *nop*. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20220926093214.506243-10-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-09-26 12:32:02 +03:00
WITH_JOB_LOCK_GUARD() {
job = job_get_locked("job0");
}
test-block-iothread: Check filter node in test_propagate_mirror Just make the test cover the AioContext of the filter node as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-05-03 14:20:54 +03:00
filter = bdrv_find_node("filter_node");
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
/* Change the AioContext of src */
block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-11-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-25 11:49:52 +03:00
bdrv_try_change_aio_context(src, ctx, NULL, &error_abort);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
g_assert(bdrv_get_aio_context(src) == ctx);
g_assert(bdrv_get_aio_context(target) == ctx);
test-block-iothread: Check filter node in test_propagate_mirror Just make the test cover the AioContext of the filter node as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-05-03 14:20:54 +03:00
g_assert(bdrv_get_aio_context(filter) == ctx);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
g_assert(job->aio_context == ctx);
/* Change the AioContext of target */
aio_context_acquire(ctx);
block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-11-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-25 11:49:52 +03:00
bdrv_try_change_aio_context(target, main_ctx, NULL, &error_abort);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
aio_context_release(ctx);
g_assert(bdrv_get_aio_context(src) == main_ctx);
g_assert(bdrv_get_aio_context(target) == main_ctx);
test-block-iothread: Check filter node in test_propagate_mirror Just make the test cover the AioContext of the filter node as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-05-03 14:20:54 +03:00
g_assert(bdrv_get_aio_context(filter) == main_ctx);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
/* With a BlockBackend on src, changing target must fail */
block: Add BlockBackend.ctx This adds a new parameter to blk_new() which requires its callers to declare from which AioContext this BlockBackend is going to be used (or the locks of which AioContext need to be taken anyway). The given context is only stored and kept up to date when changing AioContexts. Actually applying the stored AioContext to the root node is saved for another commit. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-25 15:25:10 +03:00
blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
blk_insert_bs(blk, src, &error_abort);
block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-11-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-25 11:49:52 +03:00
bdrv_try_change_aio_context(target, ctx, NULL, &local_err);
tests: Use error_free_or_abort() where appropriate Replace g_assert(err != NULL); error_free(err); err = NULL; and variations thereof by error_free_or_abort(&err); Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200630090351.1247703-6-armbru@redhat.com>
2020-06-30 12:03:30 +03:00
error_free_or_abort(&local_err);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
g_assert(blk_get_aio_context(blk) == main_ctx);
g_assert(bdrv_get_aio_context(src) == main_ctx);
g_assert(bdrv_get_aio_context(target) == main_ctx);
test-block-iothread: Check filter node in test_propagate_mirror Just make the test cover the AioContext of the filter node as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-05-03 14:20:54 +03:00
g_assert(bdrv_get_aio_context(filter) == main_ctx);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
/* ...unless we explicitly allow it */
aio_context_acquire(ctx);
blk_set_allow_aio_context_change(blk, true);
block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-11-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-25 11:49:52 +03:00
bdrv_try_change_aio_context(target, ctx, NULL, &error_abort);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
aio_context_release(ctx);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(src) == ctx);
g_assert(bdrv_get_aio_context(target) == ctx);
test-block-iothread: Check filter node in test_propagate_mirror Just make the test cover the AioContext of the filter node as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2019-05-03 14:20:54 +03:00
g_assert(bdrv_get_aio_context(filter) == ctx);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
job_cancel_sync_all();
aio_context_acquire(ctx);
block: Add Error to blk_set_aio_context() Add an Error parameter to blk_set_aio_context() and use bdrv_child_try_set_aio_context() internally to check whether all involved nodes can actually support the AioContext switch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-02 12:10:59 +03:00
blk_set_aio_context(blk, main_ctx, &error_abort);
block: remove bdrv_try_set_aio_context and replace it with bdrv_try_change_aio_context No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221025084952.2139888-11-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-25 11:49:52 +03:00
bdrv_try_change_aio_context(target, main_ctx, NULL, &error_abort);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
aio_context_release(ctx);
blk_unref(blk);
bdrv_unref(src);
bdrv_unref(target);
}
test-block-iothread: Test adding parent to iothread node Opening a new parent node for a node that has already been moved into a different AioContext must cause the new parent to move into the same context. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:49:33 +03:00
static void test_attach_second_node(void)
{
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
AioContext *main_ctx = qemu_get_aio_context();
BlockBackend *blk;
BlockDriverState *bs, *filter;
QDict *options;
blk = blk_new(ctx, BLK_PERM_ALL, BLK_PERM_ALL);
bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
blk_insert_bs(blk, bs, &error_abort);
options = qdict_new();
qdict_put_str(options, "driver", "raw");
qdict_put_str(options, "file", "base");
filter = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs) == ctx);
g_assert(bdrv_get_aio_context(filter) == ctx);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_acquire(ctx);
test-block-iothread: Test adding parent to iothread node Opening a new parent node for a node that has already been moved into a different AioContext must cause the new parent to move into the same context. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:49:33 +03:00
blk_set_aio_context(blk, main_ctx, &error_abort);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_release(ctx);
test-block-iothread: Test adding parent to iothread node Opening a new parent node for a node that has already been moved into a different AioContext must cause the new parent to move into the same context. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:49:33 +03:00
g_assert(blk_get_aio_context(blk) == main_ctx);
g_assert(bdrv_get_aio_context(bs) == main_ctx);
g_assert(bdrv_get_aio_context(filter) == main_ctx);
bdrv_unref(filter);
bdrv_unref(bs);
blk_unref(blk);
}
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
static void test_attach_preserve_blk_ctx(void)
{
IOThread *iothread = iothread_new();
AioContext *ctx = iothread_get_aio_context(iothread);
BlockBackend *blk;
BlockDriverState *bs;
blk = blk_new(ctx, BLK_PERM_ALL, BLK_PERM_ALL);
bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
bs->total_sectors = 65536 / BDRV_SECTOR_SIZE;
/* Add node to BlockBackend that has an iothread context assigned */
blk_insert_bs(blk, bs, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs) == ctx);
/* Remove the node again */
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_acquire(ctx);
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
blk_remove_bs(blk);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_release(ctx);
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
g_assert(blk_get_aio_context(blk) == ctx);
block: Move node without parents to main AioContext A node should only be in a non-default AioContext if a user is attached to it that requires this. When the last parent of a node is gone, it can move back to the main AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 19:04:42 +03:00
g_assert(bdrv_get_aio_context(bs) == qemu_get_aio_context());
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
/* Re-attach the node */
blk_insert_bs(blk, bs, &error_abort);
g_assert(blk_get_aio_context(blk) == ctx);
g_assert(bdrv_get_aio_context(bs) == ctx);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_acquire(ctx);
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
tests: Lock AioContexts in test-block-iothread When changing a node's AioContext, the caller must acquire the old AioContext (unless it currently runs in that old context). Therefore, unless the node currently is in the main context, we always have to acquire the old context around calls that may change a node's AioContext. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 12:26:13 +03:00
aio_context_release(ctx);
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
bdrv_unref(bs);
blk_unref(blk);
}
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
int main(int argc, char **argv)
{
int i;
bdrv_init();
qemu_init_main_loop(&error_abort);
g_test_init(&argc, &argv, NULL);
for (i = 0; i < ARRAY_SIZE(sync_op_tests); i++) {
const SyncOpTest *t = &sync_op_tests[i];
g_test_add_data_func(t->name, t, test_sync_op);
}
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
g_test_add_func("/attach/blockjob", test_attach_blockjob);
test-block-iothread: Test adding parent to iothread node Opening a new parent node for a node that has already been moved into a different AioContext must cause the new parent to move into the same context. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:49:33 +03:00
g_test_add_func("/attach/second_node", test_attach_second_node);
test-block-iothread: BlockBackend AioContext across root node change Test that BlockBackends preserve their assigned AioContext even when the root node goes away. Inserting a new root node will move it to the right AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-24 18:47:34 +03:00
g_test_add_func("/attach/preserve_blk_ctx", test_attach_preserve_blk_ctx);
test-block-iothread: Test AioContext propagation through the tree Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:00 +03:00
g_test_add_func("/propagate/basic", test_propagate_basic);
g_test_add_func("/propagate/diamond", test_propagate_diamond);
test-block-iothread: Test AioContext propagation for block jobs Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-06 20:18:05 +03:00
g_test_add_func("/propagate/mirror", test_propagate_mirror);
test-block-iothread: Job coroutine thread after AioContext switch This tests that a job coroutine always runs in the right iothread after the AioContext of its main node has changed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-03 20:17:44 +03:00
block: Fix hangs in synchronous APIs with iothreads In the block layer, synchronous APIs are often implemented by creating a coroutine that calls the asynchronous coroutine-based implementation and then waiting for completion with BDRV_POLL_WHILE(). For this to work with iothreads (more specifically, when the synchronous API is called in a thread that is not the home thread of the block device, so that the coroutine will run in a different thread), we must make sure to call aio_wait_kick() at the end of the operation. Many places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if the condition has long become false. Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is generally not enough for most other operations because they haven't set the return value in the coroutine entry stub yet. To avoid race conditions there, we need to kick after setting the return value. The race window is small enough that the problem doesn't usually surface in the common path. However, it does surface and causes easily reproducible hangs if the operation can return early before even calling bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op success paths). The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is slightly different: These functions even neglected to schedule the coroutine in the home thread of the node. This avoids the hang, but is obviously wrong, too. Fix those to schedule the coroutine in the right AioContext in addition to adding aio_wait_kick() calls. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-07 15:02:48 +03:00
return g_test_run();
}
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