diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 191 |
1 files changed, 143 insertions, 48 deletions
@@ -239,12 +239,6 @@ bool bdrv_is_read_only(BlockDriverState *bs) return bs->read_only; } -/* Returns whether the image file can be written to right now */ -bool bdrv_is_writable(BlockDriverState *bs) -{ - return !bdrv_is_read_only(bs) && !(bs->open_flags & BDRV_O_INACTIVE); -} - int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, bool ignore_allow_rdw, Error **errp) { @@ -1531,22 +1525,59 @@ static int bdrv_fill_options(QDict **options, const char *filename, return 0; } -static int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared, +static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, + uint64_t perm, uint64_t shared, GSList *ignore_children, Error **errp); static void bdrv_child_abort_perm_update(BdrvChild *c); static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared); +typedef struct BlockReopenQueueEntry { + bool prepared; + BDRVReopenState state; + QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; +} BlockReopenQueueEntry; + +/* + * Return the flags that @bs will have after the reopens in @q have + * successfully completed. If @q is NULL (or @bs is not contained in @q), + * return the current flags. + */ +static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs) +{ + BlockReopenQueueEntry *entry; + + if (q != NULL) { + QSIMPLEQ_FOREACH(entry, q, entry) { + if (entry->state.bs == bs) { + return entry->state.flags; + } + } + } + + return bs->open_flags; +} + +/* Returns whether the image file can be written to after the reopen queue @q + * has been successfully applied, or right now if @q is NULL. */ +static bool bdrv_is_writable(BlockDriverState *bs, BlockReopenQueue *q) +{ + int flags = bdrv_reopen_get_flags(q, bs); + + return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR; +} + static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, - BdrvChild *c, - const BdrvChildRole *role, + BdrvChild *c, const BdrvChildRole *role, + BlockReopenQueue *reopen_queue, uint64_t parent_perm, uint64_t parent_shared, uint64_t *nperm, uint64_t *nshared) { if (bs->drv && bs->drv->bdrv_child_perm) { - bs->drv->bdrv_child_perm(bs, c, role, + bs->drv->bdrv_child_perm(bs, c, role, reopen_queue, parent_perm, parent_shared, nperm, nshared); } + /* TODO Take force_share from reopen_queue */ if (child_bs && child_bs->force_share) { *nshared = BLK_PERM_ALL; } @@ -1561,7 +1592,8 @@ static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, * 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, uint64_t cumulative_perms, +static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q, + uint64_t cumulative_perms, uint64_t cumulative_shared_perms, GSList *ignore_children, Error **errp) { @@ -1571,7 +1603,7 @@ static int bdrv_check_perm(BlockDriverState *bs, uint64_t cumulative_perms, /* Write permissions never work with read-only images */ if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && - !bdrv_is_writable(bs)) + !bdrv_is_writable(bs, q)) { error_setg(errp, "Block node is read-only"); return -EPERM; @@ -1596,11 +1628,11 @@ static int bdrv_check_perm(BlockDriverState *bs, uint64_t cumulative_perms, /* Check all children */ QLIST_FOREACH(c, &bs->children, next) { uint64_t cur_perm, cur_shared; - bdrv_child_perm(bs, c->bs, c, c->role, + 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, cur_perm, cur_shared, ignore_children, - errp); + ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared, + ignore_children, errp); if (ret < 0) { return ret; } @@ -1658,7 +1690,7 @@ static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms, /* Update all children */ QLIST_FOREACH(c, &bs->children, next) { uint64_t cur_perm, cur_shared; - bdrv_child_perm(bs, c->bs, c, c->role, + bdrv_child_perm(bs, c->bs, c, c->role, NULL, cumulative_perms, cumulative_shared_perms, &cur_perm, &cur_shared); bdrv_child_set_perm(c, cur_perm, cur_shared); @@ -1726,7 +1758,8 @@ char *bdrv_perm_names(uint64_t perm) * * 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, uint64_t new_used_perm, +static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, + uint64_t new_used_perm, uint64_t new_shared_perm, GSList *ignore_children, Error **errp) { @@ -1768,19 +1801,20 @@ static int bdrv_check_update_perm(BlockDriverState *bs, uint64_t new_used_perm, cumulative_shared_perms &= c->shared_perm; } - return bdrv_check_perm(bs, cumulative_perms, cumulative_shared_perms, + return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms, 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, uint64_t perm, uint64_t shared, +static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, + uint64_t perm, uint64_t shared, 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, perm, shared, ignore_children, errp); + ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp); g_slist_free(ignore_children); return ret; @@ -1808,7 +1842,7 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, { int ret; - ret = bdrv_child_check_perm(c, perm, shared, NULL, errp); + ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, errp); if (ret < 0) { bdrv_child_abort_perm_update(c); return ret; @@ -1827,6 +1861,7 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, const BdrvChildRole *role, + BlockReopenQueue *reopen_queue, uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) { @@ -1844,6 +1879,7 @@ void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, const BdrvChildRole *role, + BlockReopenQueue *reopen_queue, uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) { @@ -1853,10 +1889,11 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, if (!backing) { /* Apart from the modifications below, the same permissions are * forwarded and left alone as for filters */ - bdrv_filter_default_perms(bs, c, role, perm, shared, &perm, &shared); + bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared, + &perm, &shared); /* Format drivers may touch metadata even if the guest doesn't write */ - if (bdrv_is_writable(bs)) { + if (bdrv_is_writable(bs, reopen_queue)) { perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; } @@ -1945,7 +1982,7 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) * because we're just taking a parent away, so we're loosening * restrictions. */ bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm); - bdrv_check_perm(old_bs, perm, shared_perm, NULL, &error_abort); + bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, &error_abort); bdrv_set_perm(old_bs, perm, shared_perm); } @@ -1964,7 +2001,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, BdrvChild *child; int ret; - ret = bdrv_check_update_perm(child_bs, perm, shared_perm, NULL, errp); + ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp); if (ret < 0) { bdrv_abort_perm_update(child_bs); return NULL; @@ -1999,7 +2036,7 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, assert(parent_bs->drv); assert(bdrv_get_aio_context(parent_bs) == bdrv_get_aio_context(child_bs)); - bdrv_child_perm(parent_bs, child_bs, NULL, child_role, + bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL, perm, shared_perm, &perm, &shared_perm); child = bdrv_root_attach_child(child_bs, child_name, child_role, @@ -2633,12 +2670,6 @@ BlockDriverState *bdrv_open(const char *filename, const char *reference, NULL, errp); } -typedef struct BlockReopenQueueEntry { - bool prepared; - BDRVReopenState state; - QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; -} BlockReopenQueueEntry; - /* * Adds a BlockDriverState to a simple queue for an atomic, transactional * reopen of multiple devices. @@ -2737,6 +2768,23 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, flags |= BDRV_O_ALLOW_RDWR; } + if (!bs_entry) { + bs_entry = g_new0(BlockReopenQueueEntry, 1); + QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); + } else { + QDECREF(bs_entry->state.options); + QDECREF(bs_entry->state.explicit_options); + } + + bs_entry->state.bs = bs; + bs_entry->state.options = options; + bs_entry->state.explicit_options = explicit_options; + bs_entry->state.flags = flags; + + /* This needs to be overwritten in bdrv_reopen_prepare() */ + bs_entry->state.perm = UINT64_MAX; + bs_entry->state.shared_perm = 0; + QLIST_FOREACH(child, &bs->children, next) { QDict *new_child_options; char *child_key_dot; @@ -2756,19 +2804,6 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, child->role, options, flags); } - if (!bs_entry) { - bs_entry = g_new0(BlockReopenQueueEntry, 1); - QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); - } else { - QDECREF(bs_entry->state.options); - QDECREF(bs_entry->state.explicit_options); - } - - bs_entry->state.bs = bs; - bs_entry->state.options = options; - bs_entry->state.explicit_options = explicit_options; - bs_entry->state.flags = flags; - return bs_queue; } @@ -2856,6 +2891,52 @@ int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) return ret; } +static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q, + BdrvChild *c) +{ + BlockReopenQueueEntry *entry; + + QSIMPLEQ_FOREACH(entry, q, entry) { + BlockDriverState *bs = entry->state.bs; + BdrvChild *child; + + QLIST_FOREACH(child, &bs->children, next) { + if (child == c) { + return entry; + } + } + } + + return NULL; +} + +static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs, + uint64_t *perm, uint64_t *shared) +{ + BdrvChild *c; + BlockReopenQueueEntry *parent; + uint64_t cumulative_perms = 0; + uint64_t cumulative_shared_perms = BLK_PERM_ALL; + + QLIST_FOREACH(c, &bs->parents, next_parent) { + parent = find_parent_in_reopen_queue(q, c); + if (!parent) { + cumulative_perms |= c->perm; + cumulative_shared_perms &= c->shared_perm; + } else { + uint64_t nperm, nshared; + + bdrv_child_perm(parent->state.bs, bs, c, c->role, q, + parent->state.perm, parent->state.shared_perm, + &nperm, &nshared); + + cumulative_perms |= nperm; + cumulative_shared_perms &= nshared; + } + } + *perm = cumulative_perms; + *shared = cumulative_shared_perms; +} /* * Prepares a BlockDriverState for reopen. All changes are staged in the @@ -2921,6 +3002,9 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, goto error; } + /* Calculate required permissions after reopening */ + bdrv_reopen_perm(queue, reopen_state->bs, + &reopen_state->perm, &reopen_state->shared_perm); ret = bdrv_flush(reopen_state->bs); if (ret) { @@ -2976,6 +3060,12 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, } while ((entry = qdict_next(reopen_state->options, entry))); } + ret = bdrv_check_perm(reopen_state->bs, queue, reopen_state->perm, + reopen_state->shared_perm, NULL, errp); + if (ret < 0) { + goto error; + } + ret = 0; error: @@ -3016,6 +3106,9 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state) bdrv_refresh_limits(bs, NULL); + bdrv_set_perm(reopen_state->bs, reopen_state->perm, + reopen_state->shared_perm); + new_can_write = !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); if (!old_can_write && new_can_write && drv->bdrv_reopen_bitmaps_rw) { @@ -3049,6 +3142,8 @@ void bdrv_reopen_abort(BDRVReopenState *reopen_state) } QDECREF(reopen_state->explicit_options); + + bdrv_abort_perm_update(reopen_state->bs); } @@ -3179,7 +3274,7 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, /* 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, perm, shared, list, errp); + ret = bdrv_check_update_perm(to, NULL, perm, shared, list, errp); if (ret < 0) { bdrv_abort_perm_update(to); goto out; @@ -4049,7 +4144,7 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) /* Update permissions, they may differ for inactive nodes */ bdrv_get_cumulative_perm(bs, &perm, &shared_perm); - ret = bdrv_check_perm(bs, perm, shared_perm, NULL, &local_err); + ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &local_err); if (ret < 0) { bs->open_flags |= BDRV_O_INACTIVE; error_propagate(errp, local_err); @@ -4116,7 +4211,7 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs, /* Update permissions, they may differ for inactive nodes */ bdrv_get_cumulative_perm(bs, &perm, &shared_perm); - bdrv_check_perm(bs, perm, shared_perm, NULL, &error_abort); + bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &error_abort); bdrv_set_perm(bs, perm, shared_perm); } |