diff options
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 245 |
1 files changed, 120 insertions, 125 deletions
@@ -64,16 +64,16 @@ static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = static QLIST_HEAD(, BlockDriver) bdrv_drivers = QLIST_HEAD_INITIALIZER(bdrv_drivers); -static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, - const char *reference, QDict *options, int flags, - BlockDriverState *parent, - const BdrvChildRole *child_role, Error **errp); +static BlockDriverState *bdrv_open_inherit(const char *filename, + const char *reference, + QDict *options, int flags, + BlockDriverState *parent, + const BdrvChildRole *child_role, + Error **errp); /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; -static void bdrv_close(BlockDriverState *bs); - #ifdef _WIN32 static int is_windows_drive_prefix(const char *filename) { @@ -220,11 +220,6 @@ void bdrv_register(BlockDriver *bdrv) QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); } -BlockDriverState *bdrv_new_root(void) -{ - return bdrv_new(); -} - BlockDriverState *bdrv_new(void) { BlockDriverState *bs; @@ -664,6 +659,18 @@ int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough) return 0; } +static void bdrv_child_cb_drained_begin(BdrvChild *child) +{ + BlockDriverState *bs = child->opaque; + bdrv_drained_begin(bs); +} + +static void bdrv_child_cb_drained_end(BdrvChild *child) +{ + BlockDriverState *bs = child->opaque; + bdrv_drained_end(bs); +} + /* * Returns the options and flags that a temporary snapshot should get, based on * the originally requested flags (the originally requested image will have @@ -710,6 +717,8 @@ static void bdrv_inherited_options(int *child_flags, QDict *child_options, const BdrvChildRole child_file = { .inherit_options = bdrv_inherited_options, + .drained_begin = bdrv_child_cb_drained_begin, + .drained_end = bdrv_child_cb_drained_end, }; /* @@ -728,6 +737,8 @@ static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options, const BdrvChildRole child_format = { .inherit_options = bdrv_inherited_fmt_options, + .drained_begin = bdrv_child_cb_drained_begin, + .drained_end = bdrv_child_cb_drained_end, }; /* @@ -755,6 +766,8 @@ static void bdrv_backing_options(int *child_flags, QDict *child_options, static const BdrvChildRole child_backing = { .inherit_options = bdrv_backing_options, + .drained_begin = bdrv_child_cb_drained_begin, + .drained_end = bdrv_child_cb_drained_end, }; static int bdrv_open_flags(BlockDriverState *bs, int flags) @@ -1155,18 +1168,41 @@ static int bdrv_fill_options(QDict **options, const char *filename, return 0; } +static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) +{ + BlockDriverState *old_bs = child->bs; + + if (old_bs) { + if (old_bs->quiesce_counter && child->role->drained_end) { + child->role->drained_end(child); + } + QLIST_REMOVE(child, next_parent); + } + + child->bs = new_bs; + + if (new_bs) { + QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); + if (new_bs->quiesce_counter && child->role->drained_begin) { + child->role->drained_begin(child); + } + } +} + BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, const char *child_name, - const BdrvChildRole *child_role) + const BdrvChildRole *child_role, + void *opaque) { BdrvChild *child = g_new(BdrvChild, 1); *child = (BdrvChild) { - .bs = child_bs, + .bs = NULL, .name = g_strdup(child_name), .role = child_role, + .opaque = opaque, }; - QLIST_INSERT_HEAD(&child_bs->parents, child, next_parent); + bdrv_replace_child(child, child_bs); return child; } @@ -1176,7 +1212,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, const char *child_name, const BdrvChildRole *child_role) { - BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role); + BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role, + parent_bs); QLIST_INSERT_HEAD(&parent_bs->children, child, next); return child; } @@ -1187,7 +1224,9 @@ static void bdrv_detach_child(BdrvChild *child) QLIST_REMOVE(child, next); child->next.le_prev = NULL; } - QLIST_REMOVE(child, next_parent); + + bdrv_replace_child(child, NULL); + g_free(child->name); g_free(child); } @@ -1341,14 +1380,13 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qdict_put(options, "driver", qstring_from_str(bs->backing_format)); } - backing_hd = NULL; - ret = bdrv_open_inherit(&backing_hd, - *backing_filename ? backing_filename : NULL, - reference, options, 0, bs, &child_backing, - errp); - if (ret < 0) { + backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, + 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: "); + ret = -EINVAL; goto free_exit; } @@ -1388,7 +1426,6 @@ BdrvChild *bdrv_open_child(const char *filename, BdrvChild *c = NULL; BlockDriverState *bs; QDict *image_options; - int ret; char *bdref_key_dot; const char *reference; @@ -1408,10 +1445,9 @@ BdrvChild *bdrv_open_child(const char *filename, goto done; } - bs = NULL; - ret = bdrv_open_inherit(&bs, filename, reference, image_options, 0, - parent, child_role, errp); - if (ret < 0) { + bs = bdrv_open_inherit(filename, reference, image_options, 0, + parent, child_role, errp); + if (!bs) { goto done; } @@ -1422,15 +1458,16 @@ done: return c; } -static int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, - QDict *snapshot_options, Error **errp) +static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, + int flags, + QDict *snapshot_options, + Error **errp) { /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ char *tmp_filename = g_malloc0(PATH_MAX + 1); int64_t total_size; QemuOpts *opts = NULL; BlockDriverState *bs_snapshot; - Error *local_err = NULL; int ret; /* if snapshot, we create a temporary backing file and open it @@ -1439,7 +1476,6 @@ static int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, /* Get the required size from the image */ total_size = bdrv_getlength(bs); if (total_size < 0) { - ret = total_size; error_setg_errno(errp, -total_size, "Could not get image size"); goto out; } @@ -1470,22 +1506,26 @@ static int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, qdict_put(snapshot_options, "driver", qstring_from_str("qcow2")); - bs_snapshot = bdrv_new(); - - ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options, - flags, &local_err); + bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); snapshot_options = NULL; - if (ret < 0) { - error_propagate(errp, local_err); + if (!bs_snapshot) { + ret = -EINVAL; goto out; } + /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will + * call bdrv_unref() on it), so in order to be able to return one, we have + * to increase bs_snapshot's refcount here */ + bdrv_ref(bs_snapshot); bdrv_append(bs_snapshot, bs); + g_free(tmp_filename); + return bs_snapshot; + out: QDECREF(snapshot_options); g_free(tmp_filename); - return ret; + return NULL; } /* @@ -1503,10 +1543,12 @@ out: * should be opened. If specified, neither options nor a filename may be given, * nor can an existing BDS be reused (that is, *pbs has to be NULL). */ -static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, - const char *reference, QDict *options, int flags, - BlockDriverState *parent, - const BdrvChildRole *child_role, Error **errp) +static BlockDriverState *bdrv_open_inherit(const char *filename, + const char *reference, + QDict *options, int flags, + BlockDriverState *parent, + const BdrvChildRole *child_role, + Error **errp) { int ret; BdrvChild *file = NULL; @@ -1518,7 +1560,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, QDict *snapshot_options = NULL; int snapshot_flags = 0; - assert(pbs); assert(!child_role || !flags); assert(!child_role == !parent); @@ -1526,33 +1567,22 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, bool options_non_empty = options ? qdict_size(options) : false; QDECREF(options); - if (*pbs) { - error_setg(errp, "Cannot reuse an existing BDS when referencing " - "another block device"); - return -EINVAL; - } - if (filename || options_non_empty) { error_setg(errp, "Cannot reference an existing block device with " "additional options or a new filename"); - return -EINVAL; + return NULL; } bs = bdrv_lookup_bs(reference, reference, errp); if (!bs) { - return -ENODEV; + return NULL; } bdrv_ref(bs); - *pbs = bs; - return 0; + return bs; } - if (*pbs) { - bs = *pbs; - } else { - bs = bdrv_new(); - } + bs = bdrv_new(); /* NULL means an empty set of options */ if (options == NULL) { @@ -1562,7 +1592,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, /* json: syntax counts as explicit options, as if in the QDict */ parse_json_protocol(options, &filename, &local_err); if (local_err) { - ret = -EINVAL; goto fail; } @@ -1589,7 +1618,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, drv = bdrv_find_format(drvname); if (!drv) { error_setg(errp, "Unknown driver: '%s'", drvname); - ret = -EINVAL; goto fail; } } @@ -1619,7 +1647,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, file = bdrv_open_child(filename, options, "file", bs, &child_file, true, &local_err); if (local_err) { - ret = -EINVAL; goto fail; } } @@ -1646,7 +1673,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, qdict_put(options, "driver", qstring_from_str(drv->format_name)); } else if (!drv) { error_setg(errp, "Must specify either driver or file"); - ret = -EINVAL; goto fail; } @@ -1689,7 +1715,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, drv->format_name, entry->key); } - ret = -EINVAL; goto close_and_fail; } @@ -1700,25 +1725,30 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ error_setg(errp, "Guest must be stopped for opening of encrypted image"); - ret = -EBUSY; goto close_and_fail; } QDECREF(options); - *pbs = bs; /* For snapshot=on, create a temporary qcow2 overlay. bs points to the * temporary snapshot afterwards. */ if (snapshot_flags) { - ret = bdrv_append_temp_snapshot(bs, snapshot_flags, snapshot_options, - &local_err); + BlockDriverState *snapshot_bs; + snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags, + snapshot_options, &local_err); snapshot_options = NULL; if (local_err) { goto close_and_fail; } + /* We are not going to return bs but the overlay on top of it + * (snapshot_bs); thus, we have to drop the strong reference to bs + * (which we obtained by calling bdrv_new()). bs will not be deleted, + * though, because the overlay still has a reference to it. */ + bdrv_unref(bs); + bs = snapshot_bs; } - return 0; + return bs; fail: if (file != NULL) { @@ -1729,36 +1759,26 @@ fail: QDECREF(bs->options); QDECREF(options); bs->options = NULL; - if (!*pbs) { - /* If *pbs is NULL, a new BDS has been created in this function and - needs to be freed now. Otherwise, it does not need to be closed, - since it has not really been opened yet. */ - bdrv_unref(bs); - } + bdrv_unref(bs); if (local_err) { error_propagate(errp, local_err); } - return ret; + return NULL; close_and_fail: - /* See fail path, but now the BDS has to be always closed */ - if (*pbs) { - bdrv_close(bs); - } else { - bdrv_unref(bs); - } + bdrv_unref(bs); QDECREF(snapshot_options); QDECREF(options); if (local_err) { error_propagate(errp, local_err); } - return ret; + return NULL; } -int bdrv_open(BlockDriverState **pbs, const char *filename, - const char *reference, QDict *options, int flags, Error **errp) +BlockDriverState *bdrv_open(const char *filename, const char *reference, + QDict *options, int flags, Error **errp) { - return bdrv_open_inherit(pbs, filename, reference, options, flags, NULL, + return bdrv_open_inherit(filename, reference, options, flags, NULL, NULL, errp); } @@ -2132,6 +2152,7 @@ static void bdrv_close(BlockDriverState *bs) BdrvAioNotifier *ban, *ban_next; assert(!bs->job); + assert(!bs->refcnt); bdrv_drained_begin(bs); /* complete I/O */ bdrv_flush(bs); @@ -2140,8 +2161,6 @@ static void bdrv_close(BlockDriverState *bs) bdrv_release_named_dirty_bitmaps(bs); assert(QLIST_EMPTY(&bs->dirty_bitmaps)); - bdrv_parent_cb_change_media(bs, false); - if (bs->drv) { BdrvChild *child, *next; @@ -2190,8 +2209,7 @@ static void bdrv_close(BlockDriverState *bs) void bdrv_close_all(void) { - BlockDriverState *bs; - AioContext *aio_context; + block_job_cancel_sync_all(); /* Drop references from requests still in flight, such as canceled block * jobs whose AIO context has not been polled yet */ @@ -2200,25 +2218,7 @@ void bdrv_close_all(void) blk_remove_all_bs(); blockdev_close_all_bdrv_states(); - /* Cancel all block jobs */ - while (!QTAILQ_EMPTY(&all_bdrv_states)) { - QTAILQ_FOREACH(bs, &all_bdrv_states, bs_list) { - aio_context = bdrv_get_aio_context(bs); - - aio_context_acquire(aio_context); - if (bs->job) { - block_job_cancel_sync(bs->job); - aio_context_release(aio_context); - break; - } - aio_context_release(aio_context); - } - - /* All the remaining BlockDriverStates are referenced directly or - * indirectly from block jobs, so there needs to be at least one BDS - * directly used by a block job */ - assert(bs); - } + assert(QTAILQ_EMPTY(&all_bdrv_states)); } static void change_parent_backing_link(BlockDriverState *from, @@ -2228,10 +2228,8 @@ static void change_parent_backing_link(BlockDriverState *from, QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { assert(c->role != &child_backing); - c->bs = to; - QLIST_REMOVE(c, next_parent); - QLIST_INSERT_HEAD(&to->parents, c, next_parent); bdrv_ref(to); + bdrv_replace_child(c, to); bdrv_unref(from); } } @@ -3195,9 +3193,9 @@ void bdrv_invalidate_cache_all(Error **errp) { BlockDriverState *bs; Error *local_err = NULL; - BdrvNextIterator *it = NULL; + BdrvNextIterator it; - while ((it = bdrv_next(it, &bs)) != NULL) { + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { AioContext *aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); @@ -3239,11 +3237,11 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs, int bdrv_inactivate_all(void) { BlockDriverState *bs = NULL; - BdrvNextIterator *it = NULL; + BdrvNextIterator it; int ret = 0; int pass; - while ((it = bdrv_next(it, &bs)) != NULL) { + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { aio_context_acquire(bdrv_get_aio_context(bs)); } @@ -3252,8 +3250,7 @@ int bdrv_inactivate_all(void) * the second pass sets the BDRV_O_INACTIVE flag so that no further write * is allowed. */ for (pass = 0; pass < 2; pass++) { - it = NULL; - while ((it = bdrv_next(it, &bs)) != NULL) { + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { ret = bdrv_inactivate_recurse(bs, pass); if (ret < 0) { goto out; @@ -3262,8 +3259,7 @@ int bdrv_inactivate_all(void) } out: - it = NULL; - while ((it = bdrv_next(it, &bs)) != NULL) { + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { aio_context_release(bdrv_get_aio_context(bs)); } @@ -3547,11 +3543,10 @@ void bdrv_img_create(const char *filename, const char *fmt, qstring_from_str(backing_fmt)); } - bs = NULL; - ret = bdrv_open(&bs, full_backing, NULL, backing_options, - back_flags, &local_err); + bs = bdrv_open(full_backing, NULL, backing_options, back_flags, + &local_err); g_free(full_backing); - if (ret < 0) { + if (!bs) { goto out; } size = bdrv_getlength(bs); @@ -3753,10 +3748,10 @@ bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, bool bdrv_is_first_non_filter(BlockDriverState *candidate) { BlockDriverState *bs; - BdrvNextIterator *it = NULL; + BdrvNextIterator it; /* walk down the bs forest recursively */ - while ((it = bdrv_next(it, &bs)) != NULL) { + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { bool perm; /* try to recurse in this top level bs */ |