#include "qemu/timer.h"
#include "qemu/cutils.h"
#include "qemu/id.h"
+#include "qemu/range.h"
+#include "qemu/rcu.h"
#include "block/coroutines.h"
#ifdef CONFIG_BSD
BdrvChildRole child_role,
Error **errp);
-static void bdrv_replace_child_noperm(BdrvChild *child,
- BlockDriverState *new_bs);
+static bool bdrv_recurse_has_child(BlockDriverState *bs,
+ BlockDriverState *child);
+
+static void bdrv_child_free(BdrvChild *child);
+static void bdrv_replace_child_noperm(BdrvChild **child,
+ BlockDriverState *new_bs,
+ bool free_empty_child);
static void bdrv_remove_file_or_backing_child(BlockDriverState *bs,
BdrvChild *child,
Transaction *tran);
static void bdrv_reopen_commit(BDRVReopenState *reopen_state);
static void bdrv_reopen_abort(BDRVReopenState *reopen_state);
+static bool bdrv_backing_overridden(BlockDriverState *bs);
+
/* If non-zero, use only whitelisted block drivers */
static int use_bdrv_whitelist;
qemu_co_queue_init(&bs->flush_queue);
+ qemu_co_mutex_init(&bs->bsc_modify_lock);
+ bs->block_status_cache = g_new0(BdrvBlockStatusCache, 1);
+
for (i = 0; i < bdrv_drain_all_count; i++) {
bdrv_drained_begin(bs);
}
{
BlockDriverState *bs = child->opaque;
+ QLIST_INSERT_HEAD(&bs->children, child, next);
+
if (child->role & BDRV_CHILD_COW) {
bdrv_backing_attach(child);
}
}
bdrv_unapply_subtree_drain(child, bs);
+
+ QLIST_REMOVE(child, next);
}
static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base,
return ret;
}
-BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
- int flags, Error **errp)
+/*
+ * Create and open a block node.
+ *
+ * @options is a QDict of options to pass to the block drivers, or NULL for an
+ * empty set of options. The reference to the QDict belongs to the block layer
+ * after the call (even on failure), so if the caller intends to reuse the
+ * dictionary, it needs to use qobject_ref() before calling bdrv_open.
+ */
+BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
+ const char *node_name,
+ QDict *options, int flags,
+ Error **errp)
{
BlockDriverState *bs;
int ret;
bs = bdrv_new();
bs->open_flags = flags;
- bs->explicit_options = qdict_new();
- bs->options = qdict_new();
+ bs->options = options ?: qdict_new();
+ bs->explicit_options = qdict_clone_shallow(bs->options);
bs->opaque = NULL;
update_options_from_flags(bs->options, flags);
return bs;
}
+/* Create and open a block node. */
+BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
+ int flags, Error **errp)
+{
+ return bdrv_new_open_driver_opts(drv, node_name, NULL, flags, errp);
+}
+
QemuOptsList bdrv_runtime_opts = {
.name = "bdrv_common",
.head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
typedef struct BdrvReplaceChildState {
BdrvChild *child;
+ BdrvChild **childp;
BlockDriverState *old_bs;
+ bool free_empty_child;
} BdrvReplaceChildState;
static void bdrv_replace_child_commit(void *opaque)
{
BdrvReplaceChildState *s = opaque;
+ if (s->free_empty_child && !s->child->bs) {
+ bdrv_child_free(s->child);
+ }
bdrv_unref(s->old_bs);
}
BdrvReplaceChildState *s = opaque;
BlockDriverState *new_bs = s->child->bs;
- /* old_bs reference is transparently moved from @s to @s->child */
- bdrv_replace_child_noperm(s->child, s->old_bs);
+ /*
+ * old_bs reference is transparently moved from @s to s->child.
+ *
+ * Pass &s->child here instead of s->childp, because:
+ * (1) s->old_bs must be non-NULL, so bdrv_replace_child_noperm() will not
+ * modify the BdrvChild * pointer we indirectly pass to it, i.e. it
+ * will not modify s->child. From that perspective, it does not matter
+ * whether we pass s->childp or &s->child.
+ * (2) If new_bs is not NULL, s->childp will be NULL. We then cannot use
+ * it here.
+ * (3) If new_bs is NULL, *s->childp will have been NULLed by
+ * bdrv_replace_child_tran()'s bdrv_replace_child_noperm() call, and we
+ * must not pass a NULL *s->childp here.
+ *
+ * So whether new_bs was NULL or not, we cannot pass s->childp here; and in
+ * any case, there is no reason to pass it anyway.
+ */
+ bdrv_replace_child_noperm(&s->child, s->old_bs, true);
+ /*
+ * The child was pre-existing, so s->old_bs must be non-NULL, and
+ * s->child thus must not have been freed
+ */
+ assert(s->child != NULL);
+ if (!new_bs) {
+ /* As described above, *s->childp was cleared, so restore it */
+ assert(s->childp != NULL);
+ *s->childp = s->child;
+ }
bdrv_unref(new_bs);
}
* Note: real unref of old_bs is done only on commit.
*
* The function doesn't update permissions, caller is responsible for this.
+ *
+ * (*childp)->bs must not be NULL.
+ *
+ * Note that if new_bs == NULL, @childp is stored in a state object attached
+ * to @tran, so that the old child can be reinstated in the abort handler.
+ * Therefore, if @new_bs can be NULL, @childp must stay valid until the
+ * transaction is committed or aborted.
+ *
+ * If @free_empty_child is true and @new_bs is NULL, the BdrvChild is
+ * freed (on commit). @free_empty_child should only be false if the
+ * caller will free the BDrvChild themselves (which may be important
+ * if this is in turn called in another transactional context).
*/
-static void bdrv_replace_child_tran(BdrvChild *child, BlockDriverState *new_bs,
- Transaction *tran)
+static void bdrv_replace_child_tran(BdrvChild **childp,
+ BlockDriverState *new_bs,
+ Transaction *tran,
+ bool free_empty_child)
{
BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1);
*s = (BdrvReplaceChildState) {
- .child = child,
- .old_bs = child->bs,
+ .child = *childp,
+ .childp = new_bs == NULL ? childp : NULL,
+ .old_bs = (*childp)->bs,
+ .free_empty_child = free_empty_child,
};
tran_add(tran, &bdrv_replace_child_drv, s);
+ /* The abort handler relies on this */
+ assert(s->old_bs != NULL);
+
if (new_bs) {
bdrv_ref(new_bs);
}
- bdrv_replace_child_noperm(child, new_bs);
- /* old_bs reference is transparently moved from @child to @s */
+ /*
+ * Pass free_empty_child=false, we will free the child (if
+ * necessary) in bdrv_replace_child_commit() (if our
+ * @free_empty_child parameter was true).
+ */
+ bdrv_replace_child_noperm(childp, new_bs, false);
+ /* old_bs reference is transparently moved from *childp to @s */
}
/*
{ BLK_PERM_WRITE, "write" },
{ BLK_PERM_WRITE_UNCHANGED, "write unchanged" },
{ BLK_PERM_RESIZE, "resize" },
- { BLK_PERM_GRAPH_MOD, "change children" },
{ 0, NULL }
};
shared = 0;
}
- shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
- BLK_PERM_WRITE_UNCHANGED;
+ shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED;
if (bs->open_flags & BDRV_O_INACTIVE) {
shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
[BLOCK_PERMISSION_WRITE] = BLK_PERM_WRITE,
[BLOCK_PERMISSION_WRITE_UNCHANGED] = BLK_PERM_WRITE_UNCHANGED,
[BLOCK_PERMISSION_RESIZE] = BLK_PERM_RESIZE,
- [BLOCK_PERMISSION_GRAPH_MOD] = BLK_PERM_GRAPH_MOD,
};
QEMU_BUILD_BUG_ON(ARRAY_SIZE(permissions) != BLOCK_PERMISSION__MAX);
return permissions[qapi_perm];
}
-static void bdrv_replace_child_noperm(BdrvChild *child,
- BlockDriverState *new_bs)
+/**
+ * Replace (*childp)->bs by @new_bs.
+ *
+ * If @new_bs is NULL, *childp will be set to NULL, too: BDS parents
+ * generally cannot handle a BdrvChild with .bs == NULL, so clearing
+ * BdrvChild.bs should generally immediately be followed by the
+ * BdrvChild pointer being cleared as well.
+ *
+ * If @free_empty_child is true and @new_bs is NULL, the BdrvChild is
+ * freed. @free_empty_child should only be false if the caller will
+ * free the BdrvChild themselves (this may be important in a
+ * transactional context, where it may only be freed on commit).
+ */
+static void bdrv_replace_child_noperm(BdrvChild **childp,
+ BlockDriverState *new_bs,
+ bool free_empty_child)
{
+ BdrvChild *child = *childp;
BlockDriverState *old_bs = child->bs;
int new_bs_quiesce_counter;
int drain_saldo;
assert(!child->frozen);
+ assert(old_bs != new_bs);
if (old_bs && new_bs) {
assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
}
child->bs = new_bs;
+ if (!new_bs) {
+ *childp = NULL;
+ }
if (new_bs) {
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
bdrv_parent_drained_end_single(child);
drain_saldo++;
}
-}
-
-static void bdrv_child_free(void *opaque)
-{
- BdrvChild *c = opaque;
- g_free(c->name);
- g_free(c);
+ if (free_empty_child && !child->bs) {
+ bdrv_child_free(child);
+ }
}
-static void bdrv_remove_empty_child(BdrvChild *child)
+/**
+ * Free the given @child.
+ *
+ * The child must be empty (i.e. `child->bs == NULL`) and it must be
+ * unused (i.e. not in a children list).
+ */
+static void bdrv_child_free(BdrvChild *child)
{
assert(!child->bs);
- QLIST_SAFE_REMOVE(child, next);
- bdrv_child_free(child);
+ assert(!child->next.le_prev); /* not in children list */
+
+ g_free(child->name);
+ g_free(child);
}
typedef struct BdrvAttachChildCommonState {
BdrvChild *child = *s->child;
BlockDriverState *bs = child->bs;
- bdrv_replace_child_noperm(child, NULL);
+ /*
+ * Pass free_empty_child=false, because we still need the child
+ * for the AioContext operations on the parent below; those
+ * BdrvChildClass methods all work on a BdrvChild object, so we
+ * need to keep it as an empty shell (after this function, it will
+ * not be attached to any parent, and it will not have a .bs).
+ */
+ bdrv_replace_child_noperm(s->child, NULL, false);
if (bdrv_get_aio_context(bs) != s->old_child_ctx) {
bdrv_try_set_aio_context(bs, s->old_child_ctx, &error_abort);
}
if (bdrv_child_get_parent_aio_context(child) != s->old_parent_ctx) {
- GSList *ignore = g_slist_prepend(NULL, child);
+ GSList *ignore;
+ /* No need to ignore `child`, because it has been detached already */
+ ignore = NULL;
child->klass->can_set_aio_ctx(child, s->old_parent_ctx, &ignore,
&error_abort);
g_slist_free(ignore);
- ignore = g_slist_prepend(NULL, child);
- child->klass->set_aio_ctx(child, s->old_parent_ctx, &ignore);
+ ignore = NULL;
+ child->klass->set_aio_ctx(child, s->old_parent_ctx, &ignore);
g_slist_free(ignore);
}
bdrv_unref(bs);
- bdrv_remove_empty_child(child);
- *s->child = NULL;
+ bdrv_child_free(child);
}
static TransactionActionDrv bdrv_attach_child_common_drv = {
if (ret < 0) {
error_propagate(errp, local_err);
- bdrv_remove_empty_child(new_child);
+ bdrv_child_free(new_child);
return ret;
}
}
bdrv_ref(child_bs);
- bdrv_replace_child_noperm(new_child, child_bs);
+ bdrv_replace_child_noperm(&new_child, child_bs, true);
+ /* child_bs was non-NULL, so new_child must not have been freed */
+ assert(new_child != NULL);
*child = new_child;
assert(parent_bs->drv);
+ if (bdrv_recurse_has_child(child_bs, parent_bs)) {
+ error_setg(errp, "Making '%s' a %s child of '%s' would create a cycle",
+ child_bs->node_name, child_name, parent_bs->node_name);
+ return -EINVAL;
+ }
+
bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL,
perm, shared_perm, &perm, &shared_perm);
return ret;
}
- QLIST_INSERT_HEAD(&parent_bs->children, *child, next);
- /*
- * child is removed in bdrv_attach_child_common_abort(), so don't care to
- * abort this change separately.
- */
-
return 0;
}
-static void bdrv_detach_child(BdrvChild *child)
+static void bdrv_detach_child(BdrvChild **childp)
{
- BlockDriverState *old_bs = child->bs;
+ BlockDriverState *old_bs = (*childp)->bs;
- bdrv_replace_child_noperm(child, NULL);
- bdrv_remove_empty_child(child);
+ bdrv_replace_child_noperm(childp, NULL, true);
if (old_bs) {
/*
BlockDriverState *child_bs;
child_bs = child->bs;
- bdrv_detach_child(child);
+ bdrv_detach_child(&child);
bdrv_unref(child_bs);
}
int ret;
Transaction *tran = tran_new();
+ bdrv_drained_begin(bs);
+
ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp);
if (ret < 0) {
goto out;
out:
tran_finalize(tran, ret);
+ bdrv_drained_end(bs);
+
return ret;
}
bs->explicit_options = NULL;
qobject_unref(bs->full_open_options);
bs->full_open_options = NULL;
+ g_free(bs->block_status_cache);
+ bs->block_status_cache = NULL;
bdrv_release_named_dirty_bitmaps(bs);
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
typedef struct BdrvRemoveFilterOrCowChild {
BdrvChild *child;
+ BlockDriverState *bs;
bool is_backing;
} BdrvRemoveFilterOrCowChild;
BdrvRemoveFilterOrCowChild *s = opaque;
BlockDriverState *parent_bs = s->child->opaque;
- QLIST_INSERT_HEAD(&parent_bs->children, s->child, next);
if (s->is_backing) {
parent_bs->backing = s->child;
} else {
bdrv_child_free(s->child);
}
+static void bdrv_remove_filter_or_cow_child_clean(void *opaque)
+{
+ BdrvRemoveFilterOrCowChild *s = opaque;
+
+ /* Drop the bs reference after the transaction is done */
+ bdrv_unref(s->bs);
+ g_free(s);
+}
+
static TransactionActionDrv bdrv_remove_filter_or_cow_child_drv = {
.abort = bdrv_remove_filter_or_cow_child_abort,
.commit = bdrv_remove_filter_or_cow_child_commit,
- .clean = g_free,
+ .clean = bdrv_remove_filter_or_cow_child_clean,
};
/*
BdrvChild *child,
Transaction *tran)
{
+ BdrvChild **childp;
BdrvRemoveFilterOrCowChild *s;
- assert(child == bs->backing || child == bs->file);
-
if (!child) {
return;
}
+ /*
+ * Keep a reference to @bs so @childp will stay valid throughout the
+ * transaction (required by bdrv_replace_child_tran())
+ */
+ bdrv_ref(bs);
+ if (child == bs->backing) {
+ childp = &bs->backing;
+ } else if (child == bs->file) {
+ childp = &bs->file;
+ } else {
+ g_assert_not_reached();
+ }
+
if (child->bs) {
- bdrv_replace_child_tran(child, NULL, tran);
+ /*
+ * Pass free_empty_child=false, we will free the child in
+ * bdrv_remove_filter_or_cow_child_commit()
+ */
+ bdrv_replace_child_tran(childp, NULL, tran, false);
}
s = g_new(BdrvRemoveFilterOrCowChild, 1);
*s = (BdrvRemoveFilterOrCowChild) {
.child = child,
- .is_backing = (child == bs->backing),
+ .bs = bs,
+ .is_backing = (childp == &bs->backing),
};
tran_add(tran, &bdrv_remove_filter_or_cow_child_drv, s);
-
- QLIST_SAFE_REMOVE(child, next);
- if (s->is_backing) {
- bs->backing = NULL;
- } else {
- bs->file = NULL;
- }
}
/*
{
BdrvChild *c, *next;
+ assert(to != NULL);
+
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
assert(c->bs == from);
if (!should_update_child(c, to)) {
c->name, from->node_name);
return -EPERM;
}
- bdrv_replace_child_tran(c, to, tran);
+
+ /*
+ * Passing a pointer to the local variable @c is fine here, because
+ * @to is not NULL, and so &c will not be attached to the transaction.
+ */
+ bdrv_replace_child_tran(&c, to, tran, true);
}
return 0;
*
* With @detach_subchain=true @to must be in a backing chain of @from. In this
* case backing link of the cow-parent of @to is removed.
+ *
+ * @to must not be NULL.
*/
static int bdrv_replace_node_common(BlockDriverState *from,
BlockDriverState *to,
BlockDriverState *to_cow_parent = NULL;
int ret;
+ assert(to != NULL);
+
if (detach_subchain) {
assert(bdrv_chain_contains(from, to));
assert(from != to);
return ret;
}
+/**
+ * Replace node @from by @to (where neither may be NULL).
+ */
int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
Error **errp)
{
return ret;
}
+/* Not for empty child */
+int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
+ Error **errp)
+{
+ int ret;
+ Transaction *tran = tran_new();
+ g_autoptr(GHashTable) found = NULL;
+ g_autoptr(GSList) refresh_list = NULL;
+ BlockDriverState *old_bs = child->bs;
+
+ bdrv_ref(old_bs);
+ bdrv_drained_begin(old_bs);
+ bdrv_drained_begin(new_bs);
+
+ bdrv_replace_child_tran(&child, new_bs, tran, true);
+ /* @new_bs must have been non-NULL, so @child must not have been freed */
+ assert(child != NULL);
+
+ found = g_hash_table_new(NULL, NULL);
+ refresh_list = bdrv_topological_dfs(refresh_list, found, old_bs);
+ refresh_list = bdrv_topological_dfs(refresh_list, found, new_bs);
+
+ ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp);
+
+ tran_finalize(tran, ret);
+
+ bdrv_drained_end(old_bs);
+ bdrv_drained_end(new_bs);
+ bdrv_unref(old_bs);
+
+ return ret;
+}
+
static void bdrv_delete(BlockDriverState *bs)
{
assert(bdrv_op_blocker_is_empty(bs));
g_free(bs);
}
-BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
+
+/*
+ * Replace @bs by newly created block node.
+ *
+ * @options is a QDict of options to pass to the block drivers, or NULL for an
+ * empty set of options. The reference to the QDict belongs to the block layer
+ * after the call (even on failure), so if the caller intends to reuse the
+ * dictionary, it needs to use qobject_ref() before calling bdrv_open.
+ */
+BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options,
int flags, Error **errp)
{
- BlockDriverState *new_node_bs;
- Error *local_err = NULL;
+ ERRP_GUARD();
+ int ret;
+ BlockDriverState *new_node_bs = NULL;
+ const char *drvname, *node_name;
+ BlockDriver *drv;
- new_node_bs = bdrv_open(NULL, NULL, node_options, flags, errp);
- if (new_node_bs == NULL) {
+ drvname = qdict_get_try_str(options, "driver");
+ if (!drvname) {
+ error_setg(errp, "driver is not specified");
+ goto fail;
+ }
+
+ drv = bdrv_find_format(drvname);
+ if (!drv) {
+ error_setg(errp, "Unknown driver: '%s'", drvname);
+ goto fail;
+ }
+
+ node_name = qdict_get_try_str(options, "node-name");
+
+ new_node_bs = bdrv_new_open_driver_opts(drv, node_name, options, flags,
+ errp);
+ options = NULL; /* bdrv_new_open_driver() eats options */
+ if (!new_node_bs) {
error_prepend(errp, "Could not create node: ");
- return NULL;
+ goto fail;
}
bdrv_drained_begin(bs);
- bdrv_replace_node(bs, new_node_bs, &local_err);
+ ret = bdrv_replace_node(bs, new_node_bs, errp);
bdrv_drained_end(bs);
- if (local_err) {
- bdrv_unref(new_node_bs);
- error_propagate(errp, local_err);
- return NULL;
+ if (ret < 0) {
+ error_prepend(errp, "Could not replace node: ");
+ goto fail;
}
return new_node_bs;
+
+fail:
+ qobject_unref(options);
+ bdrv_unref(new_node_bs);
+ return NULL;
}
/*
update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top);
/* 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. */
if (!backing_file_str) {
bdrv_refresh_filename(base);
backing_file_str = base->filename;
void bdrv_init(void)
{
+#ifdef CONFIG_BDRV_WHITELIST_TOOLS
+ use_bdrv_whitelist = 1;
+#endif
module_call_init(MODULE_INIT_BLOCK);
}
{
BdrvChild *child, *parent;
int ret;
+ uint64_t cumulative_perms, cumulative_shared_perms;
if (!bs->drv) {
return -ENOMEDIUM;
}
}
+ bdrv_get_cumulative_perm(bs, &cumulative_perms,
+ &cumulative_shared_perms);
+ if (cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
+ /* Our inactive parents still need write access. Inactivation failed. */
+ return -EPERM;
+ }
+
bs->open_flags |= BDRV_O_INACTIVE;
/*
/* 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. */
-bool bdrv_backing_overridden(BlockDriverState *bs)
+static bool bdrv_backing_overridden(BlockDriverState *bs)
{
if (bs->backing) {
return strcmp(bs->auto_backing_file,
{
return bdrv_skip_filters(bdrv_cow_bs(bdrv_skip_filters(bs)));
}
+
+/**
+ * Check whether [offset, offset + bytes) overlaps with the cached
+ * block-status data region.
+ *
+ * If so, and @pnum is not NULL, set *pnum to `bsc.data_end - offset`,
+ * which is what bdrv_bsc_is_data()'s interface needs.
+ * Otherwise, *pnum is not touched.
+ */
+static bool bdrv_bsc_range_overlaps_locked(BlockDriverState *bs,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum)
+{
+ BdrvBlockStatusCache *bsc = qatomic_rcu_read(&bs->block_status_cache);
+ bool overlaps;
+
+ overlaps =
+ qatomic_read(&bsc->valid) &&
+ ranges_overlap(offset, bytes, bsc->data_start,
+ bsc->data_end - bsc->data_start);
+
+ if (overlaps && pnum) {
+ *pnum = bsc->data_end - offset;
+ }
+
+ return overlaps;
+}
+
+/**
+ * See block_int.h for this function's documentation.
+ */
+bool bdrv_bsc_is_data(BlockDriverState *bs, int64_t offset, int64_t *pnum)
+{
+ RCU_READ_LOCK_GUARD();
+
+ return bdrv_bsc_range_overlaps_locked(bs, offset, 1, pnum);
+}
+
+/**
+ * See block_int.h for this function's documentation.
+ */
+void bdrv_bsc_invalidate_range(BlockDriverState *bs,
+ int64_t offset, int64_t bytes)
+{
+ RCU_READ_LOCK_GUARD();
+
+ if (bdrv_bsc_range_overlaps_locked(bs, offset, bytes, NULL)) {
+ qatomic_set(&bs->block_status_cache->valid, false);
+ }
+}
+
+/**
+ * See block_int.h for this function's documentation.
+ */
+void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes)
+{
+ BdrvBlockStatusCache *new_bsc = g_new(BdrvBlockStatusCache, 1);
+ BdrvBlockStatusCache *old_bsc;
+
+ *new_bsc = (BdrvBlockStatusCache) {
+ .valid = true,
+ .data_start = offset,
+ .data_end = offset + bytes,
+ };
+
+ QEMU_LOCK_GUARD(&bs->bsc_modify_lock);
+
+ old_bsc = qatomic_rcu_read(&bs->block_status_cache);
+ qatomic_rcu_set(&bs->block_status_cache, new_bsc);
+ if (old_bsc) {
+ g_free_rcu(old_bsc, rcu);
+ }
+}
projects / mirror_qemu.git / blobdiff