diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 130 |
1 files changed, 111 insertions, 19 deletions
diff --git a/block.c b/block.c index 6e906ec53c..5db266be21 100644 --- a/block.c +++ b/block.c @@ -192,6 +192,43 @@ void path_combine(char *dest, int dest_size, } } +bool bdrv_is_read_only(BlockDriverState *bs) +{ + return bs->read_only; +} + +int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, Error **errp) +{ + /* Do not set read_only if copy_on_read is enabled */ + if (bs->copy_on_read && read_only) { + error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled", + bdrv_get_device_or_node_name(bs)); + return -EINVAL; + } + + /* Do not clear read_only if it is prohibited */ + if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR)) { + error_setg(errp, "Node '%s' is read only", + bdrv_get_device_or_node_name(bs)); + return -EPERM; + } + + return 0; +} + +int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp) +{ + int ret = 0; + + ret = bdrv_can_set_read_only(bs, read_only, errp); + if (ret < 0) { + return ret; + } + + bs->read_only = read_only; + return 0; +} + void bdrv_get_full_backing_filename_from_filename(const char *backed, const char *backing, char *dest, size_t sz, @@ -1157,6 +1194,13 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, if (file != NULL) { filename = blk_bs(file)->filename; } else { + /* + * Caution: while qdict_get_try_str() is fine, getting + * non-string types would require more care. When @options + * come from -blockdev or blockdev_add, its members are typed + * according to the QAPI schema, but when they come from + * -drive, they're all QString. + */ filename = qdict_get_try_str(options, "filename"); } @@ -1324,6 +1368,13 @@ static int bdrv_fill_options(QDict **options, const char *filename, BlockDriver *drv = NULL; Error *local_err = NULL; + /* + * Caution: while qdict_get_try_str() is fine, getting non-string + * types would require more care. When @options come from + * -blockdev or blockdev_add, its members are typed according to + * the QAPI schema, but when they come from -drive, they're all + * QString. + */ drvname = qdict_get_try_str(*options, "driver"); if (drvname) { drv = bdrv_find_format(drvname); @@ -1358,6 +1409,7 @@ static int bdrv_fill_options(QDict **options, const char *filename, } /* Find the right block driver */ + /* See cautionary note on accessing @options above */ filename = qdict_get_try_str(*options, "filename"); if (!drvname && protocol) { @@ -1737,6 +1789,9 @@ static void bdrv_replace_child_noperm(BdrvChild *child, { BlockDriverState *old_bs = child->bs; + if (old_bs && new_bs) { + assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)); + } if (old_bs) { if (old_bs->quiesce_counter && child->role->drained_end) { child->role->drained_end(child); @@ -1837,6 +1892,7 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm); 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); @@ -1987,6 +2043,13 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qdict_extract_subqdict(parent_options, &options, bdref_key_dot); g_free(bdref_key_dot); + /* + * Caution: while qdict_get_try_str() is fine, getting non-string + * types would require more care. When @parent_options come from + * -blockdev or blockdev_add, its members are typed according to + * the QAPI schema, but when they come from -drive, they're all + * QString. + */ reference = qdict_get_try_str(parent_options, bdref_key); if (reference || qdict_haskey(options, "file.filename")) { backing_filename[0] = '\0'; @@ -2059,6 +2122,13 @@ bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key, qdict_extract_subqdict(options, &image_options, bdref_key_dot); g_free(bdref_key_dot); + /* + * Caution: while qdict_get_try_str() is fine, getting non-string + * types would require more care. When @options come from + * -blockdev or blockdev_add, its members are typed according to + * the QAPI schema, but when they come from -drive, they're all + * QString. + */ reference = qdict_get_try_str(options, bdref_key); if (!filename && !reference && !qdict_size(image_options)) { if (!allow_none) { @@ -2274,9 +2344,13 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, goto fail; } - /* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. - * FIXME: we're parsing the QDict to avoid having to create a - * QemuOpts just for this, but neither option is optimal. */ + /* + * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. + * Caution: getting a boolean member of @options requires care. + * When @options come from -blockdev or blockdev_add, members are + * typed according to the QAPI schema, but when they come from + * -drive, they're all QString. + */ if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") && !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) { flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR); @@ -2298,6 +2372,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, options = qdict_clone_shallow(options); /* Find the right image format driver */ + /* See cautionary note on accessing @options above */ drvname = qdict_get_try_str(options, "driver"); if (drvname) { drv = bdrv_find_format(drvname); @@ -2309,6 +2384,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, assert(drvname || !(flags & BDRV_O_PROTOCOL)); + /* See cautionary note on accessing @options above */ backing = qdict_get_try_str(options, "backing"); if (backing && *backing == '\0') { flags |= BDRV_O_NO_BACKING; @@ -2713,6 +2789,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, BlockDriver *drv; QemuOpts *opts; const char *value; + bool read_only; assert(reopen_state != NULL); assert(reopen_state->bs->drv != NULL); @@ -2741,12 +2818,13 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, qdict_put(reopen_state->options, "driver", qstring_from_str(value)); } - /* if we are to stay read-only, do not allow permission change - * to r/w */ - if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && - reopen_state->flags & BDRV_O_RDWR) { - error_setg(errp, "Node '%s' is read only", - bdrv_get_device_or_node_name(reopen_state->bs)); + /* If we are to stay read-only, do not allow permission change + * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is + * not set, or if the BDS still has copy_on_read enabled */ + read_only = !(reopen_state->flags & BDRV_O_RDWR); + ret = bdrv_can_set_read_only(reopen_state->bs, read_only, &local_err); + if (local_err) { + error_propagate(errp, local_err); goto error; } @@ -2787,6 +2865,13 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, do { QString *new_obj = qobject_to_qstring(entry->value); const char *new = qstring_get_str(new_obj); + /* + * Caution: while qdict_get_try_str() is fine, getting + * non-string types would require more care. When + * bs->options come from -blockdev or blockdev_add, its + * members are typed according to the QAPI schema, but + * when they come from -drive, they're all QString. + */ const char *old = qdict_get_try_str(reopen_state->bs->options, entry->key); @@ -3228,7 +3313,11 @@ int bdrv_truncate(BdrvChild *child, int64_t offset) BlockDriver *drv = bs->drv; int ret; - assert(child->perm & BLK_PERM_RESIZE); + /* FIXME: Some format block drivers use this function instead of implicitly + * growing their file by writing beyond its end. + * See bdrv_aligned_pwritev() for an explanation why we currently + * cannot assert this permission in that case. */ + // assert(child->perm & BLK_PERM_RESIZE); if (!drv) return -ENOMEDIUM; @@ -3305,11 +3394,6 @@ void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; } -bool bdrv_is_read_only(BlockDriverState *bs) -{ - return bs->read_only; -} - bool bdrv_is_sg(BlockDriverState *bs) { return bs->sg; @@ -4111,8 +4195,8 @@ bool bdrv_op_blocker_is_empty(BlockDriverState *bs) void bdrv_img_create(const char *filename, const char *fmt, const char *base_filename, const char *base_fmt, - char *options, uint64_t img_size, int flags, - Error **errp, bool quiet) + char *options, uint64_t img_size, int flags, bool quiet, + Error **errp) { QemuOptsList *create_opts = NULL; QemuOpts *opts = NULL; @@ -4278,6 +4362,11 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs) return bs->aio_context; } +void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co) +{ + aio_co_enter(bdrv_get_aio_context(bs), co); +} + static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban) { QLIST_REMOVE(ban, list); @@ -4350,11 +4439,12 @@ void bdrv_attach_aio_context(BlockDriverState *bs, void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) { - AioContext *ctx; + AioContext *ctx = bdrv_get_aio_context(bs); + aio_disable_external(ctx); + bdrv_parent_drained_begin(bs); bdrv_drain(bs); /* ensure there are no in-flight requests */ - ctx = bdrv_get_aio_context(bs); while (aio_poll(ctx, false)) { /* wait for all bottom halves to execute */ } @@ -4366,6 +4456,8 @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) */ aio_context_acquire(new_context); bdrv_attach_aio_context(bs, new_context); + bdrv_parent_drained_end(bs); + aio_enable_external(ctx); aio_context_release(new_context); } |