diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 597 |
1 files changed, 410 insertions, 187 deletions
@@ -152,53 +152,53 @@ int path_is_absolute(const char *path) #endif } -/* if filename is absolute, just copy it to dest. Otherwise, build a +/* if filename is absolute, just return its duplicate. Otherwise, build a path to it by considering it is relative to base_path. URL are supported. */ -void path_combine(char *dest, int dest_size, - const char *base_path, - const char *filename) +char *path_combine(const char *base_path, const char *filename) { + const char *protocol_stripped = NULL; const char *p, *p1; + char *result; int len; - if (dest_size <= 0) - return; if (path_is_absolute(filename)) { - pstrcpy(dest, dest_size, filename); - } else { - const char *protocol_stripped = NULL; + return g_strdup(filename); + } - if (path_has_protocol(base_path)) { - protocol_stripped = strchr(base_path, ':'); - if (protocol_stripped) { - protocol_stripped++; - } + if (path_has_protocol(base_path)) { + protocol_stripped = strchr(base_path, ':'); + if (protocol_stripped) { + protocol_stripped++; } - p = protocol_stripped ?: base_path; + } + p = protocol_stripped ?: base_path; - p1 = strrchr(base_path, '/'); + p1 = strrchr(base_path, '/'); #ifdef _WIN32 - { - const char *p2; - p2 = strrchr(base_path, '\\'); - if (!p1 || p2 > p1) - p1 = p2; + { + const char *p2; + p2 = strrchr(base_path, '\\'); + if (!p1 || p2 > p1) { + p1 = p2; } + } #endif - if (p1) - p1++; - else - p1 = base_path; - if (p1 > p) - p = p1; - len = p - base_path; - if (len > dest_size - 1) - len = dest_size - 1; - memcpy(dest, base_path, len); - dest[len] = '\0'; - pstrcat(dest, dest_size, filename); + if (p1) { + p1++; + } else { + p1 = base_path; } + if (p1 > p) { + p = p1; + } + len = p - base_path; + + result = g_malloc(len + strlen(filename) + 1); + memcpy(result, base_path, len); + strcpy(result + len, filename); + + return result; } /* @@ -303,30 +303,61 @@ fail: return -EACCES; } -void bdrv_get_full_backing_filename_from_filename(const char *backed, - const char *backing, - char *dest, size_t sz, - Error **errp) +/* + * If @backing is empty, this function returns NULL without setting + * @errp. In all other cases, NULL will only be returned with @errp + * set. + * + * Therefore, a return value of NULL without @errp set means that + * there is no backing file; if @errp is set, there is one but its + * absolute filename cannot be generated. + */ +char *bdrv_get_full_backing_filename_from_filename(const char *backed, + const char *backing, + Error **errp) { - if (backing[0] == '\0' || path_has_protocol(backing) || - path_is_absolute(backing)) - { - pstrcpy(dest, sz, backing); + if (backing[0] == '\0') { + return NULL; + } else if (path_has_protocol(backing) || path_is_absolute(backing)) { + return g_strdup(backing); } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) { error_setg(errp, "Cannot use relative backing file names for '%s'", backed); + return NULL; } else { - path_combine(dest, sz, backed, backing); + return path_combine(backed, backing); } } -void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, - Error **errp) +/* + * If @filename is empty or NULL, this function returns NULL without + * setting @errp. In all other cases, NULL will only be returned with + * @errp set. + */ +static char *bdrv_make_absolute_filename(BlockDriverState *relative_to, + const char *filename, Error **errp) { - char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; + char *dir, *full_name; - bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file, - dest, sz, errp); + if (!filename || filename[0] == '\0') { + return NULL; + } else if (path_has_protocol(filename) || path_is_absolute(filename)) { + return g_strdup(filename); + } + + dir = bdrv_dirname(relative_to, errp); + if (!dir) { + return NULL; + } + + full_name = g_strconcat(dir, filename, NULL); + g_free(dir); + return full_name; +} + +char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) +{ + return bdrv_make_absolute_filename(bs, bs->backing_file, errp); } void bdrv_register(BlockDriver *bdrv) @@ -1004,6 +1035,8 @@ static void bdrv_backing_attach(BdrvChild *c) "node is used as backing hd of '%s'", bdrv_get_device_or_node_name(parent)); + bdrv_refresh_filename(backing_hd); + parent->open_flags &= ~BDRV_O_NO_BACKING; pstrcpy(parent->backing_file, sizeof(parent->backing_file), backing_hd->filename); @@ -1413,6 +1446,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, } if (file != NULL) { + bdrv_refresh_filename(blk_bs(file)); filename = blk_bs(file)->filename; } else { /* @@ -1954,13 +1988,32 @@ static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp); g_slist_free(ignore_children); - return ret; + if (ret < 0) { + return ret; + } + + if (!c->has_backup_perm) { + c->has_backup_perm = true; + c->backup_perm = c->perm; + c->backup_shared_perm = c->shared_perm; + } + /* + * Note: it's OK if c->has_backup_perm was already set, as we can find the + * same child twice during check_perm procedure + */ + + c->perm = perm; + c->shared_perm = shared; + + return 0; } static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared) { uint64_t cumulative_perms, cumulative_shared_perms; + c->has_backup_perm = false; + c->perm = perm; c->shared_perm = shared; @@ -1971,6 +2024,12 @@ static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared) static void bdrv_child_abort_perm_update(BdrvChild *c) { + if (c->has_backup_perm) { + c->perm = c->backup_perm; + c->shared_perm = c->backup_shared_perm; + c->has_backup_perm = false; + } + bdrv_abort_perm_update(c->bs); } @@ -2309,8 +2368,6 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, bdrv_unref(backing_hd); } - bdrv_refresh_filename(bs); - out: bdrv_refresh_limits(bs, NULL); } @@ -2328,10 +2385,11 @@ out: int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *bdref_key, Error **errp) { - char *backing_filename = g_malloc0(PATH_MAX); + char *backing_filename = NULL; char *bdref_key_dot; const char *reference = NULL; int ret = 0; + bool implicit_backing = false; BlockDriverState *backing_hd; QDict *options; QDict *tmp_parent_options = NULL; @@ -2362,13 +2420,22 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, */ reference = qdict_get_try_str(parent_options, bdref_key); if (reference || qdict_haskey(options, "file.filename")) { - backing_filename[0] = '\0'; + /* keep backing_filename NULL */ } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { qobject_unref(options); goto free_exit; } else { - bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, - &local_err); + if (qdict_size(options) == 0) { + /* If the user specifies options that do not modify the + * backing file's behavior, we might still consider it the + * implicit backing file. But it's easier this way, and + * just specifying some of the backing BDS's options is + * only possible with -drive anyway (otherwise the QAPI + * schema forces the user to specify everything). */ + implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file); + } + + backing_filename = bdrv_get_full_backing_filename(bs, &local_err); if (local_err) { ret = -EINVAL; error_propagate(errp, local_err); @@ -2389,9 +2456,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qdict_put_str(options, "driver", bs->backing_format); } - backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, - reference, options, 0, bs, &child_backing, - errp); + backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs, + &child_backing, errp); if (!backing_hd) { bs->open_flags |= BDRV_O_NO_BACKING; error_prepend(errp, "Could not open backing file: "); @@ -2400,6 +2466,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, } bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs)); + if (implicit_backing) { + bdrv_refresh_filename(backing_hd); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_hd->filename); + } + /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ bdrv_set_backing_hd(bs, backing_hd, &local_err); @@ -2839,8 +2911,6 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, g_free(child_key_dot); } - bdrv_refresh_filename(bs); - /* Check if any unknown options were used */ if (qdict_size(options) != 0) { const QDictEntry *entry = qdict_first(options); @@ -3285,6 +3355,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, if (local_err != NULL) { error_propagate(errp, local_err); } else { + bdrv_refresh_filename(reopen_state->bs); error_setg(errp, "failed while preparing to reopen image '%s'", reopen_state->bs->filename); } @@ -3542,7 +3613,9 @@ void bdrv_close_all(void) static bool should_update_child(BdrvChild *c, BlockDriverState *to) { - BdrvChild *to_c; + GQueue *queue; + GHashTable *found; + bool ret; if (c->role->stay_at_node) { return false; @@ -3578,14 +3651,43 @@ static bool should_update_child(BdrvChild *c, BlockDriverState *to) * if A is a child of B, that means we cannot replace A by B there * because that would create a loop. Silently detaching A from B * is also not really an option. So overall just leaving A in - * place there is the most sensible choice. */ - QLIST_FOREACH(to_c, &to->children, next) { - if (to_c == c) { - return false; + * place there is the most sensible choice. + * + * We would also create a loop in any cases where @c is only + * indirectly referenced by @to. Prevent this by returning false + * if @c is found (by breadth-first search) anywhere in the whole + * subtree of @to. + */ + + ret = true; + found = g_hash_table_new(NULL, NULL); + g_hash_table_add(found, to); + queue = g_queue_new(); + g_queue_push_tail(queue, to); + + while (!g_queue_is_empty(queue)) { + BlockDriverState *v = g_queue_pop_head(queue); + BdrvChild *c2; + + QLIST_FOREACH(c2, &v->children, next) { + if (c2 == c) { + ret = false; + break; + } + + if (g_hash_table_contains(found, c2->bs)) { + continue; + } + + g_queue_push_tail(queue, c2->bs); + g_hash_table_add(found, c2->bs); } } - return true; + g_queue_free(queue); + g_hash_table_destroy(found); + + return ret; } void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, @@ -3789,6 +3891,8 @@ int bdrv_change_backing_file(BlockDriverState *bs, if (ret == 0) { pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_file ?: ""); } return ret; } @@ -3881,7 +3985,10 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, /* success - we can delete the intermediate states, and link top->base */ /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once * we've figured out how they should work. */ - backing_file_str = backing_file_str ? backing_file_str : base->filename; + if (!backing_file_str) { + bdrv_refresh_filename(base); + backing_file_str = base->filename; + } QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) { /* Check whether we are allowed to switch c from top to base */ @@ -4429,16 +4536,6 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP; } -const char *bdrv_get_encrypted_filename(BlockDriverState *bs) -{ - if (bs->backing && bs->backing->bs->encrypted) - return bs->backing_file; - else if (bs->encrypted) - return bs->filename; - else - return NULL; -} - void bdrv_get_backing_filename(BlockDriverState *bs, char *filename, int filename_size) { @@ -4547,7 +4644,6 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, int is_protocol = 0; BlockDriverState *curr_bs = NULL; BlockDriverState *retval = NULL; - Error *local_error = NULL; if (!bs || !bs->drv || !backing_file) { return NULL; @@ -4555,7 +4651,6 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, filename_full = g_malloc(PATH_MAX); backing_file_full = g_malloc(PATH_MAX); - filename_tmp = g_malloc(PATH_MAX); is_protocol = path_has_protocol(backing_file); @@ -4564,41 +4659,43 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, /* If either of the filename paths is actually a protocol, then * compare unmodified paths; otherwise make paths relative */ if (is_protocol || path_has_protocol(curr_bs->backing_file)) { + char *backing_file_full_ret; + if (strcmp(backing_file, curr_bs->backing_file) == 0) { retval = curr_bs->backing->bs; break; } /* Also check against the full backing filename for the image */ - bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX, - &local_error); - if (local_error == NULL) { - if (strcmp(backing_file, backing_file_full) == 0) { + backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs, + NULL); + if (backing_file_full_ret) { + bool equal = strcmp(backing_file, backing_file_full_ret) == 0; + g_free(backing_file_full_ret); + if (equal) { retval = curr_bs->backing->bs; break; } - } else { - error_free(local_error); - local_error = NULL; } } else { /* If not an absolute filename path, make it relative to the current * image's filename path */ - path_combine(filename_tmp, PATH_MAX, curr_bs->filename, - backing_file); - - /* We are going to compare absolute pathnames */ - if (!realpath(filename_tmp, filename_full)) { + filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file, + NULL); + /* We are going to compare canonicalized absolute pathnames */ + if (!filename_tmp || !realpath(filename_tmp, filename_full)) { + g_free(filename_tmp); continue; } + g_free(filename_tmp); /* We need to make sure the backing filename we are comparing against * is relative to the current image filename (or absolute) */ - path_combine(filename_tmp, PATH_MAX, curr_bs->filename, - curr_bs->backing_file); - - if (!realpath(filename_tmp, backing_file_full)) { + filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL); + if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) { + g_free(filename_tmp); continue; } + g_free(filename_tmp); if (strcmp(backing_file_full, filename_full) == 0) { retval = curr_bs->backing->bs; @@ -4609,7 +4706,6 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, g_free(filename_full); g_free(backing_file_full); - g_free(filename_tmp); return retval; } @@ -5096,17 +5192,17 @@ void bdrv_img_create(const char *filename, const char *fmt, size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size); if (backing_file && !(flags & BDRV_O_NO_BACKING)) { BlockDriverState *bs; - char *full_backing = g_new0(char, PATH_MAX); + char *full_backing; int back_flags; QDict *backing_options = NULL; - bdrv_get_full_backing_filename_from_filename(filename, backing_file, - full_backing, PATH_MAX, - &local_err); + full_backing = + bdrv_get_full_backing_filename_from_filename(filename, backing_file, + &local_err); if (local_err) { - g_free(full_backing); goto out; } + assert(full_backing); /* backing files always opened read-only */ back_flags = flags; @@ -5227,6 +5323,9 @@ void bdrv_detach_aio_context(BlockDriverState *bs) bdrv_detach_aio_context(child->bs); } + if (bs->quiesce_counter) { + aio_enable_external(bs->aio_context); + } bs->aio_context = NULL; } @@ -5240,6 +5339,10 @@ void bdrv_attach_aio_context(BlockDriverState *bs, return; } + if (bs->quiesce_counter) { + aio_disable_external(new_context); + } + bs->aio_context = new_context; QLIST_FOREACH(child, &bs->children, next) { @@ -5261,18 +5364,16 @@ void bdrv_attach_aio_context(BlockDriverState *bs, bs->walking_aio_notifiers = false; } +/* The caller must own the AioContext lock for the old AioContext of bs, but it + * must not own the AioContext lock for new_context (unless new_context is + * the same as the current context of bs). */ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) { - AioContext *ctx = bdrv_get_aio_context(bs); - - aio_disable_external(ctx); - bdrv_parent_drained_begin(bs, NULL, false); - bdrv_drain(bs); /* ensure there are no in-flight requests */ - - while (aio_poll(ctx, false)) { - /* wait for all bottom halves to execute */ + if (bdrv_get_aio_context(bs) == new_context) { + return; } + bdrv_drained_begin(bs); bdrv_detach_aio_context(bs); /* This function executes in the old AioContext so acquire the new one in @@ -5280,8 +5381,7 @@ 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, NULL, false); - aio_enable_external(ctx); + bdrv_drained_end(bs); aio_context_release(new_context); } @@ -5435,33 +5535,113 @@ out: return to_replace_bs; } -static bool append_open_options(QDict *d, BlockDriverState *bs) +/** + * Iterates through the list of runtime option keys that are said to + * be "strong" for a BDS. An option is called "strong" if it changes + * a BDS's data. For example, the null block driver's "size" and + * "read-zeroes" options are strong, but its "latency-ns" option is + * not. + * + * If a key returned by this function ends with a dot, all options + * starting with that prefix are strong. + */ +static const char *const *strong_options(BlockDriverState *bs, + const char *const *curopt) +{ + static const char *const global_options[] = { + "driver", "filename", NULL + }; + + if (!curopt) { + return &global_options[0]; + } + + curopt++; + if (curopt == &global_options[ARRAY_SIZE(global_options) - 1] && bs->drv) { + curopt = bs->drv->strong_runtime_opts; + } + + return (curopt && *curopt) ? curopt : NULL; +} + +/** + * Copies all strong runtime options from bs->options to the given + * QDict. The set of strong option keys is determined by invoking + * strong_options(). + * + * Returns true iff any strong option was present in bs->options (and + * thus copied to the target QDict) with the exception of "filename" + * and "driver". The caller is expected to use this value to decide + * whether the existence of strong options prevents the generation of + * a plain filename. + */ +static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs) { - const QDictEntry *entry; - QemuOptDesc *desc; bool found_any = false; + const char *const *option_name = NULL; - for (entry = qdict_first(bs->options); entry; - entry = qdict_next(bs->options, entry)) - { - /* Exclude all non-driver-specific options */ - for (desc = bdrv_runtime_opts.desc; desc->name; desc++) { - if (!strcmp(qdict_entry_key(entry), desc->name)) { - break; + if (!bs->drv) { + return false; + } + + while ((option_name = strong_options(bs, option_name))) { + bool option_given = false; + + assert(strlen(*option_name) > 0); + if ((*option_name)[strlen(*option_name) - 1] != '.') { + QObject *entry = qdict_get(bs->options, *option_name); + if (!entry) { + continue; + } + + qdict_put_obj(d, *option_name, qobject_ref(entry)); + option_given = true; + } else { + const QDictEntry *entry; + for (entry = qdict_first(bs->options); entry; + entry = qdict_next(bs->options, entry)) + { + if (strstart(qdict_entry_key(entry), *option_name, NULL)) { + qdict_put_obj(d, qdict_entry_key(entry), + qobject_ref(qdict_entry_value(entry))); + option_given = true; + } } } - if (desc->name) { - continue; + + /* While "driver" and "filename" need to be included in a JSON filename, + * their existence does not prohibit generation of a plain filename. */ + if (!found_any && option_given && + strcmp(*option_name, "driver") && strcmp(*option_name, "filename")) + { + found_any = true; } + } - qdict_put_obj(d, qdict_entry_key(entry), - qobject_ref(qdict_entry_value(entry))); - found_any = true; + if (!qdict_haskey(d, "driver")) { + /* Drivers created with bdrv_new_open_driver() may not have a + * @driver option. Add it here. */ + qdict_put_str(d, "driver", bs->drv->format_name); } return found_any; } +/* Note: This function may return false positives; it may return true + * even if opening the backing file specified by bs's image header + * would result in exactly bs->backing. */ +static bool bdrv_backing_overridden(BlockDriverState *bs) +{ + if (bs->backing) { + return strcmp(bs->auto_backing_file, + bs->backing->bs->filename); + } else { + /* No backing BDS, so if the image header reports any backing + * file, it must have been suppressed */ + return bs->auto_backing_file[0] != '\0'; + } +} + /* Updates the following BDS fields: * - exact_filename: A filename which may be used for opening a block device * which (mostly) equals the given BDS (even without any @@ -5477,92 +5657,108 @@ static bool append_open_options(QDict *d, BlockDriverState *bs) void bdrv_refresh_filename(BlockDriverState *bs) { BlockDriver *drv = bs->drv; + BdrvChild *child; QDict *opts; + bool backing_overridden; + bool generate_json_filename; /* Whether our default implementation should + fill exact_filename (false) or not (true) */ if (!drv) { return; } - /* This BDS's file name will most probably depend on its file's name, so - * refresh that first */ - if (bs->file) { - bdrv_refresh_filename(bs->file->bs); + /* This BDS's file name may depend on any of its children's file names, so + * refresh those first */ + QLIST_FOREACH(child, &bs->children, next) { + bdrv_refresh_filename(child->bs); + } + + if (bs->implicit) { + /* For implicit nodes, just copy everything from the single child */ + child = QLIST_FIRST(&bs->children); + assert(QLIST_NEXT(child, next) == NULL); + + pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), + child->bs->exact_filename); + pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename); + + bs->full_open_options = qobject_ref(child->bs->full_open_options); + + return; + } + + backing_overridden = bdrv_backing_overridden(bs); + + if (bs->open_flags & BDRV_O_NO_IO) { + /* Without I/O, the backing file does not change anything. + * Therefore, in such a case (primarily qemu-img), we can + * pretend the backing file has not been overridden even if + * it technically has been. */ + backing_overridden = false; } + /* Gather the options QDict */ + opts = qdict_new(); + generate_json_filename = append_strong_runtime_options(opts, bs); + generate_json_filename |= backing_overridden; + + if (drv->bdrv_gather_child_options) { + /* Some block drivers may not want to present all of their children's + * options, or name them differently from BdrvChild.name */ + drv->bdrv_gather_child_options(bs, opts, backing_overridden); + } else { + QLIST_FOREACH(child, &bs->children, next) { + if (child->role == &child_backing && !backing_overridden) { + /* We can skip the backing BDS if it has not been overridden */ + continue; + } + + qdict_put(opts, child->name, + qobject_ref(child->bs->full_open_options)); + } + + if (backing_overridden && !bs->backing) { + /* Force no backing file */ + qdict_put_null(opts, "backing"); + } + } + + qobject_unref(bs->full_open_options); + bs->full_open_options = opts; + if (drv->bdrv_refresh_filename) { /* Obsolete information is of no use here, so drop the old file name * information before refreshing it */ bs->exact_filename[0] = '\0'; - if (bs->full_open_options) { - qobject_unref(bs->full_open_options); - bs->full_open_options = NULL; - } - opts = qdict_new(); - append_open_options(opts, bs); - drv->bdrv_refresh_filename(bs, opts); - qobject_unref(opts); + drv->bdrv_refresh_filename(bs); } else if (bs->file) { /* Try to reconstruct valid information from the underlying file */ - bool has_open_options; bs->exact_filename[0] = '\0'; - if (bs->full_open_options) { - qobject_unref(bs->full_open_options); - bs->full_open_options = NULL; - } - - opts = qdict_new(); - has_open_options = append_open_options(opts, bs); - /* If no specific options have been given for this BDS, the filename of - * the underlying file should suffice for this one as well */ - if (bs->file->bs->exact_filename[0] && !has_open_options) { + /* + * We can use the underlying file's filename if: + * - it has a filename, + * - the file is a protocol BDS, and + * - opening that file (as this BDS's format) will automatically create + * the BDS tree we have right now, that is: + * - the user did not significantly change this BDS's behavior with + * some explicit (strong) options + * - no non-file child of this BDS has been overridden by the user + * Both of these conditions are represented by generate_json_filename. + */ + if (bs->file->bs->exact_filename[0] && + bs->file->bs->drv->bdrv_file_open && + !generate_json_filename) + { strcpy(bs->exact_filename, bs->file->bs->exact_filename); } - /* Reconstructing the full options QDict is simple for most format block - * drivers, as long as the full options are known for the underlying - * file BDS. The full options QDict of that file BDS should somehow - * contain a representation of the filename, therefore the following - * suffices without querying the (exact_)filename of this BDS. */ - if (bs->file->bs->full_open_options) { - qdict_put_str(opts, "driver", drv->format_name); - qdict_put(opts, "file", - qobject_ref(bs->file->bs->full_open_options)); - - bs->full_open_options = opts; - } else { - qobject_unref(opts); - } - } else if (!bs->full_open_options && qdict_size(bs->options)) { - /* There is no underlying file BDS (at least referenced by BDS.file), - * so the full options QDict should be equal to the options given - * specifically for this block device when it was opened (plus the - * driver specification). - * Because those options don't change, there is no need to update - * full_open_options when it's already set. */ - - opts = qdict_new(); - append_open_options(opts, bs); - qdict_put_str(opts, "driver", drv->format_name); - - if (bs->exact_filename[0]) { - /* This may not work for all block protocol drivers (some may - * require this filename to be parsed), but we have to find some - * default solution here, so just include it. If some block driver - * does not support pure options without any filename at all or - * needs some special format of the options QDict, it needs to - * implement the driver-specific bdrv_refresh_filename() function. - */ - qdict_put_str(opts, "filename", bs->exact_filename); - } - - bs->full_open_options = opts; } if (bs->exact_filename[0]) { pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); - } else if (bs->full_open_options) { + } else { QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); snprintf(bs->filename, sizeof(bs->filename), "json:%s", qstring_get_str(json)); @@ -5570,6 +5766,33 @@ void bdrv_refresh_filename(BlockDriverState *bs) } } +char *bdrv_dirname(BlockDriverState *bs, Error **errp) +{ + BlockDriver *drv = bs->drv; + + if (!drv) { + error_setg(errp, "Node '%s' is ejected", bs->node_name); + return NULL; + } + + if (drv->bdrv_dirname) { + return drv->bdrv_dirname(bs, errp); + } + + if (bs->file) { + return bdrv_dirname(bs->file->bs, errp); + } + + bdrv_refresh_filename(bs); + if (bs->exact_filename[0] != '\0') { + return path_combine(bs->exact_filename, ""); + } + + error_setg(errp, "Cannot generate a base directory for %s nodes", + drv->format_name); + return NULL; +} + /* * Hot add/remove a BDS's child. So the user can take a child offline when * it is broken and take a new child online |