diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 127 |
1 files changed, 111 insertions, 16 deletions
diff --git a/block.c b/block.c index a45b9b5c29..50ba264143 100644 --- a/block.c +++ b/block.c @@ -192,11 +192,20 @@ void path_combine(char *dest, int dest_size, } } +/* Returns whether the image file is opened as read-only. Note that this can + * return false and writing to the image file is still not possible because the + * image is inactivated. */ 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, Error **errp) { /* Do not set read_only if copy_on_read is enabled */ @@ -762,6 +771,13 @@ static void bdrv_child_cb_drained_end(BdrvChild *child) bdrv_drained_end(bs); } +static int bdrv_child_cb_inactivate(BdrvChild *child) +{ + BlockDriverState *bs = child->opaque; + assert(bs->open_flags & BDRV_O_INACTIVE); + return 0; +} + /* * Returns the options and flags that a temporary snapshot should get, based on * the originally requested flags (the originally requested image will have @@ -800,6 +816,7 @@ static void bdrv_inherited_options(int *child_flags, QDict *child_options, * the parent. */ qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); + qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); /* Inherit the read-only option from the parent if it's not set */ qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); @@ -821,6 +838,7 @@ const BdrvChildRole child_file = { .inherit_options = bdrv_inherited_options, .drained_begin = bdrv_child_cb_drained_begin, .drained_end = bdrv_child_cb_drained_end, + .inactivate = bdrv_child_cb_inactivate, }; /* @@ -842,6 +860,7 @@ const BdrvChildRole child_format = { .inherit_options = bdrv_inherited_fmt_options, .drained_begin = bdrv_child_cb_drained_begin, .drained_end = bdrv_child_cb_drained_end, + .inactivate = bdrv_child_cb_inactivate, }; static void bdrv_backing_attach(BdrvChild *c) @@ -908,6 +927,7 @@ static void bdrv_backing_options(int *child_flags, QDict *child_options, * which is only applied on the top level (BlockBackend) */ qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); + qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); /* backing files always opened read-only */ qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); @@ -926,6 +946,7 @@ const BdrvChildRole child_backing = { .inherit_options = bdrv_backing_options, .drained_begin = bdrv_child_cb_drained_begin, .drained_end = bdrv_child_cb_drained_end, + .inactivate = bdrv_child_cb_inactivate, }; static int bdrv_open_flags(BlockDriverState *bs, int flags) @@ -1150,6 +1171,11 @@ QemuOptsList bdrv_runtime_opts = { .type = QEMU_OPT_STRING, .help = "discard operation (ignore/off, unmap/on)", }, + { + .name = BDRV_OPT_FORCE_SHARE, + .type = QEMU_OPT_BOOL, + .help = "always accept other writers (default: off)", + }, { /* end of list */ } }, }; @@ -1189,6 +1215,16 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, drv = bdrv_find_format(driver_name); assert(drv != NULL); + bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false); + + if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) { + error_setg(errp, + BDRV_OPT_FORCE_SHARE + "=on can only be used with read-only images"); + ret = -EINVAL; + goto fail_opts; + } + if (file != NULL) { filename = blk_bs(file)->filename; } else { @@ -1448,6 +1484,22 @@ static int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared, static void bdrv_child_abort_perm_update(BdrvChild *c); static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared); +static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, + BdrvChild *c, + const BdrvChildRole *role, + 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, + parent_perm, parent_shared, + nperm, nshared); + } + if (child_bs && child_bs->force_share) { + *nshared = BLK_PERM_ALL; + } +} + /* * Check whether permissions on this node can be changed in a way that * @cumulative_perms and @cumulative_shared_perms are the new cumulative @@ -1467,7 +1519,7 @@ 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_read_only(bs)) + !bdrv_is_writable(bs)) { error_setg(errp, "Block node is read-only"); return -EPERM; @@ -1492,9 +1544,9 @@ 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; - drv->bdrv_child_perm(bs, c, c->role, - cumulative_perms, cumulative_shared_perms, - &cur_perm, &cur_shared); + bdrv_child_perm(bs, c->bs, c, c->role, + cumulative_perms, cumulative_shared_perms, + &cur_perm, &cur_shared); ret = bdrv_child_check_perm(c, cur_perm, cur_shared, ignore_children, errp); if (ret < 0) { @@ -1554,9 +1606,9 @@ 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; - drv->bdrv_child_perm(bs, c, c->role, - cumulative_perms, cumulative_shared_perms, - &cur_perm, &cur_shared); + bdrv_child_perm(bs, c->bs, c, c->role, + cumulative_perms, cumulative_shared_perms, + &cur_perm, &cur_shared); bdrv_child_set_perm(c, cur_perm, cur_shared); } } @@ -1586,7 +1638,7 @@ static char *bdrv_child_user_desc(BdrvChild *c) return g_strdup("another user"); } -static char *bdrv_perm_names(uint64_t perm) +char *bdrv_perm_names(uint64_t perm) { struct perm_name { uint64_t perm; @@ -1752,7 +1804,7 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, bdrv_filter_default_perms(bs, c, role, perm, shared, &perm, &shared); /* Format drivers may touch metadata even if the guest doesn't write */ - if (!bdrv_is_read_only(bs)) { + if (bdrv_is_writable(bs)) { perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; } @@ -1778,6 +1830,10 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, BLK_PERM_WRITE_UNCHANGED; } + if (bs->open_flags & BDRV_O_INACTIVE) { + shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; + } + *nperm = perm; *nshared = shared; } @@ -1891,8 +1947,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, assert(parent_bs->drv); assert(bdrv_get_aio_context(parent_bs) == bdrv_get_aio_context(child_bs)); - parent_bs->drv->bdrv_child_perm(parent_bs, NULL, child_role, - perm, shared_perm, &perm, &shared_perm); + bdrv_child_perm(parent_bs, child_bs, NULL, child_role, + perm, shared_perm, &perm, &shared_perm); child = bdrv_root_attach_child(child_bs, child_name, child_role, perm, shared_perm, parent_bs, errp); @@ -3916,7 +3972,8 @@ void bdrv_init_with_whitelist(void) void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) { - BdrvChild *child; + BdrvChild *child, *parent; + uint64_t perm, shared_perm; Error *local_err = NULL; int ret; @@ -3952,6 +4009,26 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) error_setg_errno(errp, -ret, "Could not refresh total sector count"); return; } + + /* 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); + if (ret < 0) { + bs->open_flags |= BDRV_O_INACTIVE; + error_propagate(errp, local_err); + return; + } + bdrv_set_perm(bs, perm, shared_perm); + + QLIST_FOREACH(parent, &bs->parents, next_parent) { + if (parent->role->activate) { + parent->role->activate(parent, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + } + } } void bdrv_invalidate_cache_all(Error **errp) @@ -3976,7 +4053,7 @@ void bdrv_invalidate_cache_all(Error **errp) static int bdrv_inactivate_recurse(BlockDriverState *bs, bool setting_flag) { - BdrvChild *child; + BdrvChild *child, *parent; int ret; if (!setting_flag && bs->drv->bdrv_inactivate) { @@ -3986,6 +4063,27 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs, } } + if (setting_flag) { + uint64_t perm, shared_perm; + + bs->open_flags |= BDRV_O_INACTIVE; + + QLIST_FOREACH(parent, &bs->parents, next_parent) { + if (parent->role->inactivate) { + ret = parent->role->inactivate(parent); + if (ret < 0) { + bs->open_flags &= ~BDRV_O_INACTIVE; + return ret; + } + } + } + + /* 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_set_perm(bs, perm, shared_perm); + } + QLIST_FOREACH(child, &bs->children, next) { ret = bdrv_inactivate_recurse(child->bs, setting_flag); if (ret < 0) { @@ -3993,9 +4091,6 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs, } } - if (setting_flag) { - bs->open_flags |= BDRV_O_INACTIVE; - } return 0; } |