diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 190 |
1 files changed, 136 insertions, 54 deletions
@@ -2955,37 +2955,74 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) } } -/* - * This function steals the reference to child_bs from the caller. - * That reference is later dropped by bdrv_root_unref_child(). - * - * On failure NULL is returned, errp is set and the reference to - * child_bs is also dropped. - * - * The caller must hold the AioContext lock @child_bs, but not that of @ctx - * (unless @child_bs is already in @ctx). - */ -BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, - const char *child_name, - const BdrvChildClass *child_class, - BdrvChildRole child_role, - uint64_t perm, uint64_t shared_perm, - void *opaque, Error **errp) +static void bdrv_remove_empty_child(BdrvChild *child) { - BdrvChild *child; - Error *local_err = NULL; - int ret; - AioContext *ctx; + assert(!child->bs); + QLIST_SAFE_REMOVE(child, next); + g_free(child->name); + g_free(child); +} - ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp); - if (ret < 0) { - bdrv_abort_perm_update(child_bs); - bdrv_unref(child_bs); - return NULL; +typedef struct BdrvAttachChildCommonState { + BdrvChild **child; + AioContext *old_parent_ctx; + AioContext *old_child_ctx; +} BdrvAttachChildCommonState; + +static void bdrv_attach_child_common_abort(void *opaque) +{ + BdrvAttachChildCommonState *s = opaque; + BdrvChild *child = *s->child; + BlockDriverState *bs = child->bs; + + bdrv_replace_child_noperm(child, NULL); + + if (bdrv_get_aio_context(bs) != s->old_child_ctx) { + bdrv_try_set_aio_context(bs, s->old_child_ctx, &error_abort); } - child = g_new(BdrvChild, 1); - *child = (BdrvChild) { + if (bdrv_child_get_parent_aio_context(child) != s->old_parent_ctx) { + GSList *ignore = g_slist_prepend(NULL, child); + + child->klass->can_set_aio_ctx(child, s->old_parent_ctx, &ignore, + &error_abort); + g_slist_free(ignore); + ignore = g_slist_prepend(NULL, child); + child->klass->set_aio_ctx(child, s->old_parent_ctx, &ignore); + + g_slist_free(ignore); + } + + bdrv_unref(bs); + bdrv_remove_empty_child(child); + *s->child = NULL; +} + +static TransactionActionDrv bdrv_attach_child_common_drv = { + .abort = bdrv_attach_child_common_abort, + .clean = g_free, +}; + +/* + * Common part of attaching bdrv child to bs or to blk or to job + */ +static int bdrv_attach_child_common(BlockDriverState *child_bs, + const char *child_name, + const BdrvChildClass *child_class, + BdrvChildRole child_role, + uint64_t perm, uint64_t shared_perm, + void *opaque, BdrvChild **child, + Transaction *tran, Error **errp) +{ + BdrvChild *new_child; + AioContext *parent_ctx; + AioContext *child_ctx = bdrv_get_aio_context(child_bs); + + assert(child); + assert(*child == NULL); + + new_child = g_new(BdrvChild, 1); + *new_child = (BdrvChild) { .bs = NULL, .name = g_strdup(child_name), .klass = child_class, @@ -2995,37 +3032,92 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, .opaque = opaque, }; - ctx = bdrv_child_get_parent_aio_context(child); - - /* If the AioContexts don't match, first try to move the subtree of + /* + * If the AioContexts don't match, first try to move the subtree of * child_bs into the AioContext of the new parent. If this doesn't work, - * try moving the parent into the AioContext of child_bs instead. */ - if (bdrv_get_aio_context(child_bs) != ctx) { - ret = bdrv_try_set_aio_context(child_bs, ctx, &local_err); + * try moving the parent into the AioContext of child_bs instead. + */ + parent_ctx = bdrv_child_get_parent_aio_context(new_child); + if (child_ctx != parent_ctx) { + Error *local_err = NULL; + int ret = bdrv_try_set_aio_context(child_bs, parent_ctx, &local_err); + if (ret < 0 && child_class->can_set_aio_ctx) { - GSList *ignore = g_slist_prepend(NULL, child); - ctx = bdrv_get_aio_context(child_bs); - if (child_class->can_set_aio_ctx(child, ctx, &ignore, NULL)) { + GSList *ignore = g_slist_prepend(NULL, new_child); + if (child_class->can_set_aio_ctx(new_child, child_ctx, &ignore, + NULL)) + { error_free(local_err); ret = 0; g_slist_free(ignore); - ignore = g_slist_prepend(NULL, child); - child_class->set_aio_ctx(child, ctx, &ignore); + ignore = g_slist_prepend(NULL, new_child); + child_class->set_aio_ctx(new_child, child_ctx, &ignore); } g_slist_free(ignore); } + if (ret < 0) { error_propagate(errp, local_err); - g_free(child); - bdrv_abort_perm_update(child_bs); - bdrv_unref(child_bs); - return NULL; + bdrv_remove_empty_child(new_child); + return ret; } } - /* This performs the matching bdrv_set_perm() for the above check. */ - bdrv_replace_child(child, child_bs); + bdrv_ref(child_bs); + bdrv_replace_child_noperm(new_child, child_bs); + *child = new_child; + + BdrvAttachChildCommonState *s = g_new(BdrvAttachChildCommonState, 1); + *s = (BdrvAttachChildCommonState) { + .child = child, + .old_parent_ctx = parent_ctx, + .old_child_ctx = child_ctx, + }; + tran_add(tran, &bdrv_attach_child_common_drv, s); + + return 0; +} + +static void bdrv_detach_child(BdrvChild *child) +{ + bdrv_replace_child(child, NULL); + bdrv_remove_empty_child(child); +} + +/* + * This function steals the reference to child_bs from the caller. + * That reference is later dropped by bdrv_root_unref_child(). + * + * On failure NULL is returned, errp is set and the reference to + * child_bs is also dropped. + * + * The caller must hold the AioContext lock @child_bs, but not that of @ctx + * (unless @child_bs is already in @ctx). + */ +BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, + const char *child_name, + const BdrvChildClass *child_class, + BdrvChildRole child_role, + uint64_t perm, uint64_t shared_perm, + void *opaque, Error **errp) +{ + int ret; + BdrvChild *child = NULL; + Transaction *tran = tran_new(); + + ret = bdrv_attach_child_common(child_bs, child_name, child_class, + child_role, perm, shared_perm, opaque, + &child, tran, errp); + if (ret < 0) { + bdrv_unref(child_bs); + return NULL; + } + + ret = bdrv_refresh_perms(child_bs, errp); + tran_finalize(tran, ret); + + bdrv_unref(child_bs); return child; } @@ -3067,16 +3159,6 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, return child; } -static void bdrv_detach_child(BdrvChild *child) -{ - QLIST_SAFE_REMOVE(child, next); - - bdrv_replace_child(child, NULL); - - g_free(child->name); - g_free(child); -} - /* Callers must ensure that child->frozen is false. */ void bdrv_root_unref_child(BdrvChild *child) { |