diff options
| -rw-r--r-- | block.c | 89 |
1 files changed, 17 insertions, 72 deletions
@@ -1900,8 +1900,7 @@ static int bdrv_fill_options(QDict **options, const char *filename, static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, uint64_t perm, uint64_t shared, - GSList *ignore_children, - bool *tighten_restrictions, Error **errp); + GSList *ignore_children, Error **errp); static void bdrv_child_abort_perm_update(BdrvChild *c); static void bdrv_child_set_perm(BdrvChild *c); @@ -1974,43 +1973,18 @@ static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, * permissions of all its parents. This involves checking whether all necessary * permission changes to child nodes can be performed. * - * Will set *tighten_restrictions to true if and only if new permissions have to - * be taken or currently shared permissions are to be unshared. Otherwise, - * errors are not fatal as long as the caller accepts that the restrictions - * remain tighter than they need to be. The caller still has to abort the - * transaction. - * @tighten_restrictions cannot be used together with @q: When reopening, we may - * encounter fatal errors even though no restrictions are to be tightened. For - * example, changing a node from RW to RO will fail if the WRITE permission is - * to be kept. - * * A call to this function must always be followed by a call to bdrv_set_perm() * or bdrv_abort_perm_update(). */ static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q, uint64_t cumulative_perms, uint64_t cumulative_shared_perms, - GSList *ignore_children, - bool *tighten_restrictions, Error **errp) + GSList *ignore_children, Error **errp) { BlockDriver *drv = bs->drv; BdrvChild *c; int ret; - assert(!q || !tighten_restrictions); - - if (tighten_restrictions) { - uint64_t current_perms, current_shared; - uint64_t added_perms, removed_shared_perms; - - bdrv_get_cumulative_perm(bs, ¤t_perms, ¤t_shared); - - added_perms = cumulative_perms & ~current_perms; - removed_shared_perms = current_shared & ~cumulative_shared_perms; - - *tighten_restrictions = added_perms || removed_shared_perms; - } - /* Write permissions never work with read-only images */ if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && !bdrv_is_writable_after_reopen(bs, q)) @@ -2067,18 +2041,12 @@ static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q, /* Check all children */ QLIST_FOREACH(c, &bs->children, next) { uint64_t cur_perm, cur_shared; - bool child_tighten_restr; bdrv_child_perm(bs, c->bs, c, c->role, q, cumulative_perms, cumulative_shared_perms, &cur_perm, &cur_shared); ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared, ignore_children, - tighten_restrictions ? &child_tighten_restr - : NULL, errp); - if (tighten_restrictions) { - *tighten_restrictions |= child_tighten_restr; - } if (ret < 0) { return ret; } @@ -2201,22 +2169,18 @@ char *bdrv_perm_names(uint64_t perm) * set, the BdrvChild objects in this list are ignored in the calculations; * this allows checking permission updates for an existing reference. * - * See bdrv_check_perm() for the semantics of @tighten_restrictions. - * * Needs to be followed by a call to either bdrv_set_perm() or * bdrv_abort_perm_update(). */ static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, uint64_t new_used_perm, uint64_t new_shared_perm, GSList *ignore_children, - bool *tighten_restrictions, Error **errp) { BdrvChild *c; uint64_t cumulative_perms = new_used_perm; uint64_t cumulative_shared_perms = new_shared_perm; - assert(!q || !tighten_restrictions); /* There is no reason why anyone couldn't tolerate write_unchanged */ assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED); @@ -2230,10 +2194,6 @@ static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, char *user = bdrv_child_user_desc(c); char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm); - if (tighten_restrictions) { - *tighten_restrictions = true; - } - error_setg(errp, "Conflicts with use by %s as '%s', which does not " "allow '%s' on %s", user, c->name, perm_names, bdrv_get_node_name(c->bs)); @@ -2246,10 +2206,6 @@ static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, char *user = bdrv_child_user_desc(c); char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm); - if (tighten_restrictions) { - *tighten_restrictions = true; - } - error_setg(errp, "Conflicts with use by %s as '%s', which uses " "'%s' on %s", user, c->name, perm_names, bdrv_get_node_name(c->bs)); @@ -2263,21 +2219,19 @@ static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, } return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms, - ignore_children, tighten_restrictions, errp); + ignore_children, errp); } /* Needs to be followed by a call to either bdrv_child_set_perm() or * bdrv_child_abort_perm_update(). */ static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, uint64_t perm, uint64_t shared, - GSList *ignore_children, - bool *tighten_restrictions, Error **errp) + GSList *ignore_children, Error **errp) { int ret; ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c); - ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, - tighten_restrictions, errp); + ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp); g_slist_free(ignore_children); if (ret < 0) { @@ -2318,15 +2272,13 @@ static void bdrv_child_abort_perm_update(BdrvChild *c) bdrv_abort_perm_update(c->bs); } -static int bdrv_refresh_perms(BlockDriverState *bs, bool *tighten_restrictions, - Error **errp) +static int bdrv_refresh_perms(BlockDriverState *bs, Error **errp) { int ret; uint64_t perm, shared_perm; bdrv_get_cumulative_perm(bs, &perm, &shared_perm); - ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, - tighten_restrictions, errp); + ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, errp); if (ret < 0) { bdrv_abort_perm_update(bs); return ret; @@ -2341,13 +2293,12 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, { Error *local_err = NULL; int ret; - bool tighten_restrictions; - ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, - &tighten_restrictions, &local_err); + ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, &local_err); if (ret < 0) { bdrv_child_abort_perm_update(c); - if (tighten_restrictions) { + if ((perm & ~c->perm) || (c->shared_perm & ~shared)) { + /* tighten permissions */ error_propagate(errp, local_err); } else { /* @@ -2649,15 +2600,12 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) } if (old_bs) { - bool tighten_restrictions; - /* * Update permissions for old node. We're just taking a parent away, so * we're loosening restrictions. Errors of permission update are not * fatal in this case, ignore them. */ - bdrv_refresh_perms(old_bs, &tighten_restrictions, NULL); - assert(tighten_restrictions == false); + bdrv_refresh_perms(old_bs, NULL); /* When the parent requiring a non-default AioContext is removed, the * node moves back to the main AioContext */ @@ -2687,8 +2635,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, Error *local_err = NULL; int ret; - ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, NULL, - errp); + 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); @@ -3820,7 +3767,7 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) QTAILQ_FOREACH(bs_entry, bs_queue, entry) { BDRVReopenState *state = &bs_entry->state; ret = bdrv_check_perm(state->bs, bs_queue, state->perm, - state->shared_perm, NULL, NULL, errp); + state->shared_perm, NULL, errp); if (ret < 0) { goto cleanup_perm; } @@ -3832,7 +3779,7 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) bs_queue, state->perm, state->shared_perm, &nperm, &nshared); ret = bdrv_check_update_perm(state->new_backing_bs, NULL, - nperm, nshared, NULL, NULL, errp); + nperm, nshared, NULL, errp); if (ret < 0) { goto cleanup_perm; } @@ -4622,7 +4569,7 @@ static void bdrv_replace_node_common(BlockDriverState *from, /* Check whether the required permissions can be granted on @to, ignoring * all BdrvChild in @list so that they can't block themselves. */ - ret = bdrv_check_update_perm(to, NULL, perm, shared, list, NULL, errp); + ret = bdrv_check_update_perm(to, NULL, perm, shared, list, errp); if (ret < 0) { bdrv_abort_perm_update(to); goto out; @@ -5817,7 +5764,7 @@ int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp) */ if (bs->open_flags & BDRV_O_INACTIVE) { bs->open_flags &= ~BDRV_O_INACTIVE; - ret = bdrv_refresh_perms(bs, NULL, errp); + ret = bdrv_refresh_perms(bs, errp); if (ret < 0) { bs->open_flags |= BDRV_O_INACTIVE; return ret; @@ -5896,7 +5843,6 @@ static bool bdrv_has_bds_parent(BlockDriverState *bs, bool only_active) static int bdrv_inactivate_recurse(BlockDriverState *bs) { BdrvChild *child, *parent; - bool tighten_restrictions; int ret; if (!bs->drv) { @@ -5935,8 +5881,7 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs) * We only tried to loosen restrictions, so errors are not fatal, ignore * them. */ - bdrv_refresh_perms(bs, &tighten_restrictions, NULL); - assert(tighten_restrictions == false); + bdrv_refresh_perms(bs, NULL); /* Recursively inactivate children */ QLIST_FOREACH(child, &bs->children, next) { |