diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 35 |
1 files changed, 33 insertions, 2 deletions
@@ -3366,6 +3366,10 @@ static BdrvChildRole bdrv_backing_role(BlockDriverState *bs) * callers which don't need their own reference any more must call bdrv_unref(). * * Function doesn't update permissions, caller is responsible for this. + * + * The caller must hold the AioContext lock for @child_bs. Both @parent_bs and + * @child_bs can move to a different AioContext in this function. Callers must + * make sure that their AioContext locking is still correct after this. */ static int bdrv_set_file_or_backing_noperm(BlockDriverState *parent_bs, BlockDriverState *child_bs, @@ -3454,6 +3458,11 @@ out: return 0; } +/* + * The caller must hold the AioContext lock for @backing_hd. Both @bs and + * @backing_hd can move to a different AioContext in this function. Callers must + * make sure that their AioContext locking is still correct after this. + */ static int bdrv_set_backing_noperm(BlockDriverState *bs, BlockDriverState *backing_hd, Transaction *tran, Error **errp) @@ -4606,6 +4615,11 @@ int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, * backing BlockDriverState (or NULL). * * Return 0 on success, otherwise return < 0 and set @errp. + * + * The caller must hold the AioContext lock of @reopen_state->bs. + * @reopen_state->bs can move to a different AioContext in this function. + * Callers must make sure that their AioContext locking is still correct after + * this. */ static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, bool is_backing, Transaction *tran, @@ -4618,6 +4632,8 @@ static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, const char *child_name = is_backing ? "backing" : "file"; QObject *value; const char *str; + AioContext *ctx, *old_ctx; + int ret; GLOBAL_STATE_CODE(); @@ -4682,8 +4698,22 @@ static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, reopen_state->old_file_bs = old_child_bs; } - return bdrv_set_file_or_backing_noperm(bs, new_child_bs, is_backing, - tran, errp); + old_ctx = bdrv_get_aio_context(bs); + ctx = bdrv_get_aio_context(new_child_bs); + if (old_ctx != ctx) { + aio_context_release(old_ctx); + aio_context_acquire(ctx); + } + + ret = bdrv_set_file_or_backing_noperm(bs, new_child_bs, is_backing, + tran, errp); + + if (old_ctx != ctx) { + aio_context_release(ctx); + aio_context_acquire(old_ctx); + } + + return ret; } /* @@ -4702,6 +4732,7 @@ static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, * It is the responsibility of the caller to then call the abort() or * commit() for any other BDS that have been left in a prepare() state * + * The caller must hold the AioContext lock of @reopen_state->bs. */ static int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, |