From 3ea67e08832775a28d0bd2795f01bc77e7ea1512 Mon Sep 17 00:00:00 2001 From: Sergio Lopez Date: Wed, 8 Jan 2020 15:31:34 +0100 Subject: [PATCH] blockdev: honor bdrv_try_set_aio_context() context requirements bdrv_try_set_aio_context() requires that the old context is held, and the new context is not held. Fix all the occurrences where it's not done this way. Suggested-by: Max Reitz Signed-off-by: Sergio Lopez Signed-off-by: Kevin Wolf --- blockdev.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 60 insertions(+), 8 deletions(-) diff --git a/blockdev.c b/blockdev.c index 152a0f7454..1dacbc20ec 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1535,6 +1535,7 @@ static void external_snapshot_prepare(BlkActionState *common, DO_UPCAST(ExternalSnapshotState, common, common); TransactionAction *action = common->action; AioContext *aio_context; + AioContext *old_context; int ret; /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar @@ -1675,7 +1676,16 @@ static void external_snapshot_prepare(BlkActionState *common, goto out; } + /* Honor bdrv_try_set_aio_context() context acquisition requirements. */ + old_context = bdrv_get_aio_context(state->new_bs); + aio_context_release(aio_context); + aio_context_acquire(old_context); + ret = bdrv_try_set_aio_context(state->new_bs, aio_context, errp); + + aio_context_release(old_context); + aio_context_acquire(aio_context); + if (ret < 0) { goto out; } @@ -1775,11 +1785,13 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) BlockDriverState *target_bs; BlockDriverState *source = NULL; AioContext *aio_context; + AioContext *old_context; QDict *options; Error *local_err = NULL; int flags; int64_t size; bool set_backing_hd = false; + int ret; assert(common->action->type == TRANSACTION_ACTION_KIND_DRIVE_BACKUP); backup = common->action->u.drive_backup.data; @@ -1868,6 +1880,21 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) goto out; } + /* Honor bdrv_try_set_aio_context() context acquisition requirements. */ + old_context = bdrv_get_aio_context(target_bs); + aio_context_release(aio_context); + aio_context_acquire(old_context); + + ret = bdrv_try_set_aio_context(target_bs, aio_context, errp); + if (ret < 0) { + bdrv_unref(target_bs); + aio_context_release(old_context); + return; + } + + aio_context_release(old_context); + aio_context_acquire(aio_context); + if (set_backing_hd) { bdrv_set_backing_hd(target_bs, source, &local_err); if (local_err) { @@ -1947,6 +1974,8 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp) BlockDriverState *bs; BlockDriverState *target_bs; AioContext *aio_context; + AioContext *old_context; + int ret; assert(common->action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP); backup = common->action->u.blockdev_backup.data; @@ -1961,7 +1990,18 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp) return; } + /* Honor bdrv_try_set_aio_context() context acquisition requirements. */ aio_context = bdrv_get_aio_context(bs); + old_context = bdrv_get_aio_context(target_bs); + aio_context_acquire(old_context); + + ret = bdrv_try_set_aio_context(target_bs, aio_context, errp); + if (ret < 0) { + aio_context_release(old_context); + return; + } + + aio_context_release(old_context); aio_context_acquire(aio_context); state->bs = bs; @@ -3562,7 +3602,6 @@ static BlockJob *do_backup_common(BackupCommon *backup, BlockJob *job = NULL; BdrvDirtyBitmap *bmap = NULL; int job_flags = JOB_DEFAULT; - int ret; if (!backup->has_speed) { backup->speed = 0; @@ -3586,11 +3625,6 @@ static BlockJob *do_backup_common(BackupCommon *backup, backup->compress = false; } - ret = bdrv_try_set_aio_context(target_bs, aio_context, errp); - if (ret < 0) { - return NULL; - } - if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) || (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) { /* done before desugaring 'incremental' to print the right message */ @@ -3825,6 +3859,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) BlockDriverState *bs; BlockDriverState *source, *target_bs; AioContext *aio_context; + AioContext *old_context; BlockMirrorBackingMode backing_mode; Error *local_err = NULL; QDict *options = NULL; @@ -3937,12 +3972,22 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) (arg->mode == NEW_IMAGE_MODE_EXISTING || !bdrv_has_zero_init(target_bs))); + + /* Honor bdrv_try_set_aio_context() context acquisition requirements. */ + old_context = bdrv_get_aio_context(target_bs); + aio_context_release(aio_context); + aio_context_acquire(old_context); + ret = bdrv_try_set_aio_context(target_bs, aio_context, errp); if (ret < 0) { bdrv_unref(target_bs); - goto out; + aio_context_release(old_context); + return; } + aio_context_release(old_context); + aio_context_acquire(aio_context); + blockdev_mirror_common(arg->has_job_id ? arg->job_id : NULL, bs, target_bs, arg->has_replaces, arg->replaces, arg->sync, backing_mode, zero_target, @@ -3984,6 +4029,7 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id, BlockDriverState *bs; BlockDriverState *target_bs; AioContext *aio_context; + AioContext *old_context; BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN; Error *local_err = NULL; bool zero_target; @@ -4001,10 +4047,16 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id, zero_target = (sync == MIRROR_SYNC_MODE_FULL); + /* 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(aio_context); + aio_context_acquire(old_context); ret = bdrv_try_set_aio_context(target_bs, aio_context, errp); + + aio_context_release(old_context); + aio_context_acquire(aio_context); + if (ret < 0) { goto out; }