Before doing qmp actions, we need to lock the qemu_global_mutex, so the qmp actions should not take too long time.
Unfortunately, some qmp actions need to acquire aio context and this may take a long time. So replace aio_context_acquire() by aio_context_acquire_timeout() and return ETIMEDOUT if the waiting time exceeds LOCK_TIMEOUT (default set to 3 seconds). Signed-off-by: Zhenyu Ye <yezhen...@huawei.com> --- block/qapi-sysemu.c | 7 ++++++- block/qapi.c | 6 +++++- blockdev.c | 35 ++++++++++++++++++++++++++++++----- include/block/aio.h | 1 + 4 files changed, 42 insertions(+), 7 deletions(-) diff --git a/block/qapi-sysemu.c b/block/qapi-sysemu.c index 8498402ad4..e7cd7d3c70 100644 --- a/block/qapi-sysemu.c +++ b/block/qapi-sysemu.c @@ -439,6 +439,7 @@ void qmp_block_set_io_throttle(BlockIOThrottle *arg, Error **errp) BlockDriverState *bs; BlockBackend *blk; AioContext *aio_context; + int ret; blk = qmp_get_blk(arg->has_device ? arg->device : NULL, arg->has_id ? arg->id : NULL, @@ -448,7 +449,11 @@ void qmp_block_set_io_throttle(BlockIOThrottle *arg, Error **errp) } aio_context = blk_get_aio_context(blk); - aio_context_acquire(aio_context); + ret = aio_context_acquire_timeout(aio_context, LOCK_TIMEOUT); + if (ret) { + error_setg_errno(errp, ret, "acquire aio context failed"); + return; + } bs = blk_bs(blk); if (!bs) { diff --git a/block/qapi.c b/block/qapi.c index afd9f3b4a7..ff2454daff 100644 --- a/block/qapi.c +++ b/block/qapi.c @@ -271,7 +271,11 @@ void bdrv_query_image_info(BlockDriverState *bs, Error *err = NULL; ImageInfo *info; - aio_context_acquire(bdrv_get_aio_context(bs)); + ret = aio_context_acquire_timeout(bdrv_get_aio_context(bs), LOCK_TIMEOUT); + if (ret) { + error_setg_errno(errp, ret, "acquire aio context failed"); + return; + } size = bdrv_getlength(bs); if (size < 0) { diff --git a/blockdev.c b/blockdev.c index 3848a9c8ab..ce133c89e2 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2431,6 +2431,7 @@ void qmp_block_resize(bool has_device, const char *device, BlockBackend *blk = NULL; BlockDriverState *bs; AioContext *aio_context; + int ret; bs = bdrv_lookup_bs(has_device ? device : NULL, has_node_name ? node_name : NULL, @@ -2441,7 +2442,11 @@ void qmp_block_resize(bool has_device, const char *device, } aio_context = bdrv_get_aio_context(bs); - aio_context_acquire(aio_context); + ret = aio_context_acquire_timeout(aio_context, LOCK_TIMEOUT); + if (ret) { + error_setg_errno(errp, ret, "acquire aio context failed"); + return; + } if (size < 0) { error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size"); @@ -3016,7 +3021,11 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) } aio_context = bdrv_get_aio_context(bs); - aio_context_acquire(aio_context); + ret = aio_context_acquire_timeout(aio_context, LOCK_TIMEOUT); + if (ret) { + error_setg_errno(errp, ret, "acquire aio context failed"); + return; + } if (!arg->has_mode) { arg->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS; @@ -3184,12 +3193,20 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id, /* Honor bdrv_try_set_aio_context() context acquisition requirements. */ old_context = bdrv_get_aio_context(target_bs); aio_context = bdrv_get_aio_context(bs); - aio_context_acquire(old_context); + ret = aio_context_acquire_timeout(old_context, LOCK_TIMEOUT); + if (ret) { + error_setg_errno(errp, ret, "acquire aio context failed"); + return; + } ret = bdrv_try_set_aio_context(target_bs, aio_context, errp); aio_context_release(old_context); - aio_context_acquire(aio_context); + ret = aio_context_acquire_timeout(aio_context, LOCK_TIMEOUT); + if (ret) { + error_setg_errno(errp, ret, "acquire aio context failed"); + return; + } if (ret < 0) { goto out; @@ -3603,6 +3620,7 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp) { BlockJobInfoList *head = NULL, **p_next = &head; BlockJob *job; + int ret; for (job = block_job_next(NULL); job; job = block_job_next(job)) { BlockJobInfoList *elem; @@ -3613,7 +3631,14 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp) } elem = g_new0(BlockJobInfoList, 1); aio_context = blk_get_aio_context(job->blk); - aio_context_acquire(aio_context); + ret = aio_context_acquire_timeout(aio_context, LOCK_TIMEOUT); + if (ret) { + g_free(elem); + qapi_free_BlockJobInfoList(head); + error_setg_errno(errp, ret, "acquire aio context failed"); + return NULL; + } + elem->value = block_job_query(job, errp); aio_context_release(aio_context); if (!elem->value) { diff --git a/include/block/aio.h b/include/block/aio.h index cb178cdf5a..539096f547 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -290,6 +290,7 @@ void aio_context_acquire(AioContext *ctx); /* Add timeout to aio_context_acquire(). If the time for obtaining * the lock exceeds @t, return ETIMEDOUT. */ +#define LOCK_TIMEOUT 3 int aio_context_acquire_timeout(AioContext *ctx, int t); /* Relinquish ownership of the AioContext. */ -- 2.22.0.windows.1