diff --git a/block.c b/block.c index 6720bc4f8a..186efda70f 100644 --- a/block.c +++ b/block.c @@ -2320,7 +2320,7 @@ static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, tran_add(tran, &bdrv_child_set_pem_drv, s); } -static void bdrv_drv_set_perm_commit(void *opaque) +static void GRAPH_RDLOCK bdrv_drv_set_perm_commit(void *opaque) { BlockDriverState *bs = opaque; uint64_t cumulative_perms, cumulative_shared_perms; @@ -2333,7 +2333,7 @@ static void bdrv_drv_set_perm_commit(void *opaque) } } -static void bdrv_drv_set_perm_abort(void *opaque) +static void GRAPH_RDLOCK bdrv_drv_set_perm_abort(void *opaque) { BlockDriverState *bs = opaque; GLOBAL_STATE_CODE(); @@ -2348,9 +2348,13 @@ TransactionActionDrv bdrv_drv_set_perm_drv = { .commit = bdrv_drv_set_perm_commit, }; -static int bdrv_drv_set_perm(BlockDriverState *bs, uint64_t perm, - uint64_t shared_perm, Transaction *tran, - Error **errp) +/* + * After calling this function, the transaction @tran may only be completed + * while holding a reader lock for the graph. + */ +static int GRAPH_RDLOCK +bdrv_drv_set_perm(BlockDriverState *bs, uint64_t perm, uint64_t shared_perm, + Transaction *tran, Error **errp) { GLOBAL_STATE_CODE(); if (!bs->drv) { @@ -2457,9 +2461,13 @@ bdrv_replace_child_tran(BdrvChild *child, BlockDriverState *new_bs, /* * Refresh permissions in @bs subtree. The function is intended to be called * after some graph modification that was done without permission update. + * + * After calling this function, the transaction @tran may only be completed + * while holding a reader lock for the graph. */ -static int bdrv_node_refresh_perm(BlockDriverState *bs, BlockReopenQueue *q, - Transaction *tran, Error **errp) +static int GRAPH_RDLOCK +bdrv_node_refresh_perm(BlockDriverState *bs, BlockReopenQueue *q, + Transaction *tran, Error **errp) { BlockDriver *drv = bs->drv; BdrvChild *c; @@ -2532,6 +2540,9 @@ static int bdrv_node_refresh_perm(BlockDriverState *bs, BlockReopenQueue *q, /* * @list is a product of bdrv_topological_dfs() (may be called several times) - * a topologically sorted subgraph. + * + * After calling this function, the transaction @tran may only be completed + * while holding a reader lock for the graph. */ static int GRAPH_RDLOCK bdrv_do_refresh_perms(GSList *list, BlockReopenQueue *q, Transaction *tran, @@ -2561,6 +2572,9 @@ bdrv_do_refresh_perms(GSList *list, BlockReopenQueue *q, Transaction *tran, * @list is any list of nodes. List is completed by all subtrees and * topologically sorted. It's not a problem if some node occurs in the @list * several times. + * + * After calling this function, the transaction @tran may only be completed + * while holding a reader lock for the graph. */ static int GRAPH_RDLOCK bdrv_list_refresh_perms(GSList *list, BlockReopenQueue *q, Transaction *tran, @@ -2623,7 +2637,12 @@ char *bdrv_perm_names(uint64_t perm) } -/* @tran is allowed to be NULL. In this case no rollback is possible */ +/* + * @tran is allowed to be NULL. In this case no rollback is possible. + * + * After calling this function, the transaction @tran may only be completed + * while holding a reader lock for the graph. + */ static int GRAPH_RDLOCK bdrv_refresh_perms(BlockDriverState *bs, Transaction *tran, Error **errp) { diff --git a/blockdev.c b/blockdev.c index e6eba61484..372eaf198c 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1378,6 +1378,9 @@ static void external_snapshot_action(TransactionAction *action, AioContext *aio_context; uint64_t perm, shared; + /* TODO We'll eventually have to take a writer lock in this function */ + GRAPH_RDLOCK_GUARD_MAINLOOP(); + tran_add(tran, &external_snapshot_drv, state); /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar @@ -2521,6 +2524,9 @@ void qmp_block_commit(const char *job_id, const char *device, int job_flags = JOB_DEFAULT; uint64_t top_perm, top_shared; + /* TODO We'll eventually have to take a writer lock in this function */ + GRAPH_RDLOCK_GUARD_MAINLOOP(); + if (!has_speed) { speed = 0; } diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index fda9d8b5c8..f82c14fb9c 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -413,8 +413,8 @@ struct BlockDriver { * If both conditions are met, 0 is returned. Otherwise, -errno is returned * and errp is set to an error describing the conflict. */ - int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm, - uint64_t shared, Error **errp); + int GRAPH_RDLOCK_PTR (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm, + uint64_t shared, Error **errp); /** * Called to inform the driver that the set of cumulative set of used @@ -426,7 +426,8 @@ struct BlockDriver { * This function is only invoked after bdrv_check_perm(), so block drivers * may rely on preparations made in their .bdrv_check_perm implementation. */ - void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared); + void GRAPH_RDLOCK_PTR (*bdrv_set_perm)( + BlockDriverState *bs, uint64_t perm, uint64_t shared); /* * Called to inform the driver that after a previous bdrv_check_perm() @@ -436,7 +437,7 @@ struct BlockDriver { * This function can be called even for nodes that never saw a * bdrv_check_perm() call. It is a no-op then. */ - void (*bdrv_abort_perm_update)(BlockDriverState *bs); + void GRAPH_RDLOCK_PTR (*bdrv_abort_perm_update)(BlockDriverState *bs); /** * Returns in @nperm and @nshared the permissions that the driver for @bs diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index bebcc08bce..e2304db58b 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -204,8 +204,8 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, void *opaque, Error **errp); void bdrv_root_unref_child(BdrvChild *child); -void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, - uint64_t *shared_perm); +void GRAPH_RDLOCK bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, + uint64_t *shared_perm); /** * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use