#include "block/trace.h"
#include "block/block_int.h"
#include "block/blockjob.h"
+#include "block/dirty-bitmap.h"
#include "block/fuse.h"
#include "block/nbd.h"
#include "block/qdict.h"
static void bdrv_replace_child_noperm(BdrvChild *child,
BlockDriverState *new_bs);
static void bdrv_remove_child(BdrvChild *child, Transaction *tran);
-static void bdrv_remove_filter_or_cow_child(BlockDriverState *bs,
- Transaction *tran);
static int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue,
/* The driver isn't registered, maybe we need to load a module */
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
if (!strcmp(block_driver_modules[i].format_name, format_name)) {
- block_module_load_one(block_driver_modules[i].library_name);
+ Error *local_err = NULL;
+ int rv = block_module_load(block_driver_modules[i].library_name,
+ &local_err);
+ if (rv > 0) {
+ return bdrv_do_find_format(format_name);
+ } else if (rv < 0) {
+ error_report_err(local_err);
+ }
break;
}
}
-
- return bdrv_do_find_format(format_name);
+ return NULL;
}
static int bdrv_format_is_whitelisted(const char *format_name, bool read_only)
Error *err;
} CreateCo;
-static void coroutine_fn bdrv_create_co_entry(void *opaque)
-{
- Error *local_err = NULL;
- int ret;
-
- CreateCo *cco = opaque;
- assert(cco->drv);
- GLOBAL_STATE_CODE();
-
- ret = cco->drv->bdrv_co_create_opts(cco->drv,
- cco->filename, cco->opts, &local_err);
- error_propagate(&cco->err, local_err);
- cco->ret = ret;
-}
-
-int bdrv_create(BlockDriver *drv, const char* filename,
- QemuOpts *opts, Error **errp)
+int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename,
+ QemuOpts *opts, Error **errp)
{
int ret;
-
GLOBAL_STATE_CODE();
-
- Coroutine *co;
- CreateCo cco = {
- .drv = drv,
- .filename = g_strdup(filename),
- .opts = opts,
- .ret = NOT_DONE,
- .err = NULL,
- };
+ ERRP_GUARD();
if (!drv->bdrv_co_create_opts) {
- error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
- ret = -ENOTSUP;
- goto out;
- }
-
- if (qemu_in_coroutine()) {
- /* Fast-path if already in coroutine context */
- bdrv_create_co_entry(&cco);
- } else {
- co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
- qemu_coroutine_enter(co);
- while (cco.ret == NOT_DONE) {
- aio_poll(qemu_get_aio_context(), true);
- }
+ error_setg(errp, "Driver '%s' does not support image creation",
+ drv->format_name);
+ return -ENOTSUP;
}
- ret = cco.ret;
- if (ret < 0) {
- if (cco.err) {
- error_propagate(errp, cco.err);
- } else {
- error_setg_errno(errp, -ret, "Could not create image");
- }
+ ret = drv->bdrv_co_create_opts(drv, filename, opts, errp);
+ if (ret < 0 && !*errp) {
+ error_setg_errno(errp, -ret, "Could not create image");
}
-out:
- g_free(cco.filename);
return ret;
}
bytes_to_clear = MIN(current_size, BDRV_SECTOR_SIZE);
if (bytes_to_clear) {
- ret = blk_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNMAP);
+ ret = blk_co_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNMAP);
if (ret < 0) {
error_setg_errno(errp, -ret,
"Failed to clear the new image's first sector");
return ret;
}
-int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
+int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts,
+ Error **errp)
{
QemuOpts *protocol_opts;
BlockDriver *drv;
goto out;
}
- ret = bdrv_create(drv, filename, protocol_opts, errp);
+ ret = bdrv_co_create(drv, filename, protocol_opts, errp);
out:
qemu_opts_del(protocol_opts);
qobject_unref(qdict);
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
if (block_driver_modules[i].protocol_name &&
!strcmp(block_driver_modules[i].protocol_name, protocol)) {
- block_module_load_one(block_driver_modules[i].library_name);
+ int rv = block_module_load(block_driver_modules[i].library_name, errp);
+ if (rv > 0) {
+ drv1 = bdrv_do_find_protocol(protocol);
+ } else if (rv < 0) {
+ return NULL;
+ }
break;
}
}
- drv1 = bdrv_do_find_protocol(protocol);
if (!drv1) {
error_setg(errp, "Unknown protocol '%s'", protocol);
}
static void bdrv_child_cb_drained_begin(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
- bdrv_do_drained_begin_quiesce(bs, NULL, false);
+ bdrv_do_drained_begin_quiesce(bs, NULL);
}
static bool bdrv_child_cb_drained_poll(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
- return bdrv_drain_poll(bs, false, NULL, false);
+ return bdrv_drain_poll(bs, NULL, false);
}
-static void bdrv_child_cb_drained_end(BdrvChild *child,
- int *drained_end_counter)
+static void bdrv_child_cb_drained_end(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
- bdrv_drained_end_no_poll(bs, drained_end_counter);
+ bdrv_drained_end(bs);
}
static int bdrv_child_cb_inactivate(BdrvChild *child)
return bdrv_change_aio_context(bs, ctx, visited, tran, errp);
}
-static bool bdrv_child_cb_can_set_aio_ctx(BdrvChild *child, AioContext *ctx,
- GSList **ignore, Error **errp)
-{
- BlockDriverState *bs = child->opaque;
- return bdrv_can_set_aio_context(bs, ctx, ignore, errp);
-}
-
-static void bdrv_child_cb_set_aio_ctx(BdrvChild *child, AioContext *ctx,
- GSList **ignore)
-{
- BlockDriverState *bs = child->opaque;
- return bdrv_set_aio_context_ignore(bs, ctx, ignore);
-}
-
/*
* Returns the options and flags that a temporary snapshot should get, based on
* the originally requested flags (the originally requested image will have
*child_flags = flags;
}
-static void bdrv_child_cb_attach(BdrvChild *child)
+static void GRAPH_WRLOCK bdrv_child_cb_attach(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
- assert_bdrv_graph_writable(bs);
+ assert_bdrv_graph_writable();
QLIST_INSERT_HEAD(&bs->children, child, next);
if (bs->drv->is_filter || (child->role & BDRV_CHILD_FILTERED)) {
/*
assert(!bs->file);
bs->file = child;
}
-
- bdrv_apply_subtree_drain(child, bs);
}
-static void bdrv_child_cb_detach(BdrvChild *child)
+static void GRAPH_WRLOCK bdrv_child_cb_detach(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
bdrv_backing_detach(child);
}
- bdrv_unapply_subtree_drain(child, bs);
-
- assert_bdrv_graph_writable(bs);
+ assert_bdrv_graph_writable();
QLIST_REMOVE(child, next);
if (child == bs->backing) {
assert(child != bs->file);
.attach = bdrv_child_cb_attach,
.detach = bdrv_child_cb_detach,
.inactivate = bdrv_child_cb_inactivate,
- .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
- .set_aio_ctx = bdrv_child_cb_set_aio_ctx,
.change_aio_ctx = bdrv_child_cb_change_aio_ctx,
.update_filename = bdrv_child_cb_update_filename,
.get_parent_aio_context = child_of_bds_get_parent_aio_context,
AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c)
{
- GLOBAL_STATE_CODE();
+ IO_CODE();
return c->klass->get_parent_aio_context(c);
}
goto open_failed;
}
+ assert(!(bs->supported_read_flags & ~BDRV_REQ_MASK));
+ assert(!(bs->supported_write_flags & ~BDRV_REQ_MASK));
+
+ /*
+ * Always allow the BDRV_REQ_REGISTERED_BUF optimization hint. This saves
+ * drivers that pass read/write requests through to a child the trouble of
+ * declaring support explicitly.
+ *
+ * Drivers must not propagate this flag accidentally when they initiate I/O
+ * to a bounce buffer. That case should be rare though.
+ */
+ bs->supported_read_flags |= BDRV_REQ_REGISTERED_BUF;
+ bs->supported_write_flags |= BDRV_REQ_REGISTERED_BUF;
+
ret = refresh_total_sectors(bs, bs->total_sectors);
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not refresh total sector count");
assert(is_power_of_2(bs->bl.request_alignment));
for (i = 0; i < bs->quiesce_counter; i++) {
- if (drv->bdrv_co_drain_begin) {
- drv->bdrv_co_drain_begin(bs);
+ if (drv->bdrv_drain_begin) {
+ drv->bdrv_drain_begin(bs);
}
}
GLOBAL_STATE_CODE();
/* old_bs reference is transparently moved from @s to @s->child */
+ if (!s->child->bs) {
+ /*
+ * The parents were undrained when removing old_bs from the child. New
+ * requests can't have been made, though, because the child was empty.
+ *
+ * TODO Make bdrv_replace_child_noperm() transactionable to avoid
+ * undraining the parent in the first place. Once this is done, having
+ * new_bs drained when calling bdrv_replace_child_tran() is not a
+ * requirement any more.
+ */
+ bdrv_parent_drained_begin_single(s->child);
+ assert(!bdrv_parent_drained_poll_single(s->child));
+ }
+ assert(s->child->quiesced_parent);
bdrv_replace_child_noperm(s->child, s->old_bs);
bdrv_unref(new_bs);
}
*
* Note: real unref of old_bs is done only on commit.
*
+ * Both @child->bs and @new_bs (if non-NULL) must be drained. @new_bs must be
+ * kept drained until the transaction is completed.
+ *
* The function doesn't update permissions, caller is responsible for this.
*/
static void bdrv_replace_child_tran(BdrvChild *child, BlockDriverState *new_bs,
Transaction *tran)
{
BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1);
+
+ assert(child->quiesced_parent);
+ assert(!new_bs || new_bs->quiesce_counter);
+
*s = (BdrvReplaceChildState) {
.child = child,
.old_bs = child->bs,
return 0;
}
-static int bdrv_list_refresh_perms(GSList *list, BlockReopenQueue *q,
- Transaction *tran, Error **errp)
+/*
+ * @list is a product of bdrv_topological_dfs() (may be called several times) -
+ * a topologically sorted subgraph.
+ */
+static int bdrv_do_refresh_perms(GSList *list, BlockReopenQueue *q,
+ Transaction *tran, Error **errp)
{
int ret;
BlockDriverState *bs;
return 0;
}
+/*
+ * @list is any list of nodes. List is completed by all subtrees and
+ * topologically sorted. It's not a problem if some node occurs in the @list
+ * several times.
+ */
+static int bdrv_list_refresh_perms(GSList *list, BlockReopenQueue *q,
+ Transaction *tran, Error **errp)
+{
+ g_autoptr(GHashTable) found = g_hash_table_new(NULL, NULL);
+ g_autoptr(GSList) refresh_list = NULL;
+
+ for ( ; list; list = list->next) {
+ refresh_list = bdrv_topological_dfs(refresh_list, found, list->data);
+ }
+
+ return bdrv_do_refresh_perms(refresh_list, q, tran, errp);
+}
+
void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
uint64_t *shared_perm)
{
}
-static int bdrv_refresh_perms(BlockDriverState *bs, Error **errp)
+/* @tran is allowed to be NULL. In this case no rollback is possible */
+static int bdrv_refresh_perms(BlockDriverState *bs, Transaction *tran,
+ Error **errp)
{
int ret;
- Transaction *tran = tran_new();
+ Transaction *local_tran = NULL;
g_autoptr(GSList) list = bdrv_topological_dfs(NULL, NULL, bs);
GLOBAL_STATE_CODE();
- ret = bdrv_list_refresh_perms(list, NULL, tran, errp);
- tran_finalize(tran, ret);
+ if (!tran) {
+ tran = local_tran = tran_new();
+ }
+
+ ret = bdrv_do_refresh_perms(list, NULL, tran, errp);
+
+ if (local_tran) {
+ tran_finalize(local_tran, ret);
+ }
return ret;
}
bdrv_child_set_perm(c, perm, shared, tran);
- ret = bdrv_refresh_perms(c->bs, &local_err);
+ ret = bdrv_refresh_perms(c->bs, tran, &local_err);
tran_finalize(tran, ret);
return permissions[qapi_perm];
}
+/*
+ * Replaces the node that a BdrvChild points to without updating permissions.
+ *
+ * If @new_bs is non-NULL, the parent of @child must already be drained through
+ * @child.
+ */
static void bdrv_replace_child_noperm(BdrvChild *child,
BlockDriverState *new_bs)
{
BlockDriverState *old_bs = child->bs;
int new_bs_quiesce_counter;
- int drain_saldo;
assert(!child->frozen);
+
+ /*
+ * If we want to change the BdrvChild to point to a drained node as its new
+ * child->bs, we need to make sure that its new parent is drained, too. In
+ * other words, either child->quiesce_parent must already be true or we must
+ * be able to set it and keep the parent's quiesce_counter consistent with
+ * that, but without polling or starting new requests (this function
+ * guarantees that it doesn't poll, and starting new requests would be
+ * against the invariants of drain sections).
+ *
+ * To keep things simple, we pick the first option (child->quiesce_parent
+ * must already be true). We also generalise the rule a bit to make it
+ * easier to verify in callers and more likely to be covered in test cases:
+ * The parent must be quiesced through this child even if new_bs isn't
+ * currently drained.
+ *
+ * The only exception is for callers that always pass new_bs == NULL. In
+ * this case, we obviously never need to consider the case of a drained
+ * new_bs, so we can keep the callers simpler by allowing them not to drain
+ * the parent.
+ */
+ assert(!new_bs || child->quiesced_parent);
assert(old_bs != new_bs);
GLOBAL_STATE_CODE();
assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
}
- new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0);
- drain_saldo = new_bs_quiesce_counter - child->parent_quiesce_counter;
-
- /*
- * If the new child node is drained but the old one was not, flush
- * all outstanding requests to the old child node.
- */
- while (drain_saldo > 0 && child->klass->drained_begin) {
- bdrv_parent_drained_begin_single(child, true);
- drain_saldo--;
- }
-
+ /* TODO Pull this up into the callers to avoid polling here */
+ bdrv_graph_wrlock();
if (old_bs) {
- /* Detach first so that the recursive drain sections coming from @child
- * are already gone and we only end the drain sections that came from
- * elsewhere. */
if (child->klass->detach) {
child->klass->detach(child);
}
- assert_bdrv_graph_writable(old_bs);
QLIST_REMOVE(child, next_parent);
}
child->bs = new_bs;
if (new_bs) {
- assert_bdrv_graph_writable(new_bs);
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
-
- /*
- * Detaching the old node may have led to the new node's
- * quiesce_counter having been decreased. Not a problem, we
- * just need to recognize this here and then invoke
- * drained_end appropriately more often.
- */
- assert(new_bs->quiesce_counter <= new_bs_quiesce_counter);
- drain_saldo += new_bs->quiesce_counter - new_bs_quiesce_counter;
-
- /* Attach only after starting new drained sections, so that recursive
- * drain sections coming from @child don't get an extra .drained_begin
- * callback. */
if (child->klass->attach) {
child->klass->attach(child);
}
}
+ bdrv_graph_wrunlock();
/*
- * If the old child node was drained but the new one is not, allow
- * requests to come in only after the new node has been attached.
+ * If the parent was drained through this BdrvChild previously, but new_bs
+ * is not drained, allow requests to come in only after the new node has
+ * been attached.
*/
- while (drain_saldo < 0 && child->klass->drained_end) {
+ new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0);
+ if (!new_bs_quiesce_counter && child->quiesced_parent) {
bdrv_parent_drained_end_single(child);
- drain_saldo++;
}
}
bdrv_replace_child_noperm(s->child, NULL);
if (bdrv_get_aio_context(bs) != s->old_child_ctx) {
- bdrv_try_set_aio_context(bs, s->old_child_ctx, &error_abort);
+ bdrv_try_change_aio_context(bs, s->old_child_ctx, NULL, &error_abort);
}
if (bdrv_child_get_parent_aio_context(s->child) != s->old_parent_ctx) {
- GSList *ignore;
+ Transaction *tran;
+ GHashTable *visited;
+ bool ret;
+
+ tran = tran_new();
- /* No need to ignore `child`, because it has been detached already */
- ignore = NULL;
- s->child->klass->can_set_aio_ctx(s->child, s->old_parent_ctx, &ignore,
- &error_abort);
- g_slist_free(ignore);
+ /* No need to visit `child`, because it has been detached already */
+ visited = g_hash_table_new(NULL, NULL);
+ ret = s->child->klass->change_aio_ctx(s->child, s->old_parent_ctx,
+ visited, tran, &error_abort);
+ g_hash_table_destroy(visited);
- ignore = NULL;
- s->child->klass->set_aio_ctx(s->child, s->old_parent_ctx, &ignore);
- g_slist_free(ignore);
+ /* transaction is supposed to always succeed */
+ assert(ret == true);
+ tran_commit(tran);
}
bdrv_unref(bs);
parent_ctx = bdrv_child_get_parent_aio_context(new_child);
if (child_ctx != parent_ctx) {
Error *local_err = NULL;
- int ret = bdrv_try_set_aio_context(child_bs, parent_ctx, &local_err);
-
- if (ret < 0 && child_class->can_set_aio_ctx) {
- GSList *ignore = g_slist_prepend(NULL, new_child);
- if (child_class->can_set_aio_ctx(new_child, child_ctx, &ignore,
- NULL))
- {
+ int ret = bdrv_try_change_aio_context(child_bs, parent_ctx, NULL,
+ &local_err);
+
+ if (ret < 0 && child_class->change_aio_ctx) {
+ Transaction *tran = tran_new();
+ GHashTable *visited = g_hash_table_new(NULL, NULL);
+ bool ret_child;
+
+ g_hash_table_add(visited, new_child);
+ ret_child = child_class->change_aio_ctx(new_child, child_ctx,
+ visited, tran, NULL);
+ if (ret_child == true) {
error_free(local_err);
ret = 0;
- g_slist_free(ignore);
- ignore = g_slist_prepend(NULL, new_child);
- child_class->set_aio_ctx(new_child, child_ctx, &ignore);
}
- g_slist_free(ignore);
+ tran_finalize(tran, ret_child == true ? 0 : -1);
+ g_hash_table_destroy(visited);
}
if (ret < 0) {
}
bdrv_ref(child_bs);
+ /*
+ * Let every new BdrvChild start with a drained parent. Inserting the child
+ * in the graph with bdrv_replace_child_noperm() will undrain it if
+ * @child_bs is not drained.
+ *
+ * The child was only just created and is not yet visible in global state
+ * until bdrv_replace_child_noperm() inserts it into the graph, so nobody
+ * could have sent requests and polling is not necessary.
+ *
+ * Note that this means that the parent isn't fully drained yet, we only
+ * stop new requests from coming in. This is fine, we don't care about the
+ * old requests here, they are not for this child. If another place enters a
+ * drain section for the same parent, but wants it to be fully quiesced, it
+ * will not run most of the the code in .drained_begin() again (which is not
+ * a problem, we already did this), but it will still poll until the parent
+ * is fully quiesced, so it will not be negatively affected either.
+ */
+ bdrv_parent_drained_begin_single(new_child);
bdrv_replace_child_noperm(new_child, child_bs);
BdrvAttachChildCommonState *s = g_new(BdrvAttachChildCommonState, 1);
tran, errp);
}
-static void bdrv_detach_child(BdrvChild *child)
-{
- BlockDriverState *old_bs = child->bs;
-
- GLOBAL_STATE_CODE();
- bdrv_replace_child_noperm(child, NULL);
- bdrv_child_free(child);
-
- if (old_bs) {
- /*
- * Update permissions for old node. We're just taking a parent away, so
- * we're loosening restrictions. Errors of permission update are not
- * fatal in this case, ignore them.
- */
- bdrv_refresh_perms(old_bs, NULL);
-
- /*
- * When the parent requiring a non-default AioContext is removed, the
- * node moves back to the main AioContext
- */
- bdrv_try_set_aio_context(old_bs, qemu_get_aio_context(), NULL);
- }
-}
-
/*
* This function steals the reference to child_bs from the caller.
* That reference is later dropped by bdrv_root_unref_child().
goto out;
}
- ret = bdrv_refresh_perms(child_bs, errp);
+ ret = bdrv_refresh_perms(child_bs, tran, errp);
out:
tran_finalize(tran, ret);
goto out;
}
- ret = bdrv_refresh_perms(parent_bs, errp);
+ ret = bdrv_refresh_perms(parent_bs, tran, errp);
if (ret < 0) {
goto out;
}
/* Callers must ensure that child->frozen is false. */
void bdrv_root_unref_child(BdrvChild *child)
{
- BlockDriverState *child_bs;
+ BlockDriverState *child_bs = child->bs;
GLOBAL_STATE_CODE();
+ bdrv_replace_child_noperm(child, NULL);
+ bdrv_child_free(child);
+
+ if (child_bs) {
+ /*
+ * Update permissions for old node. We're just taking a parent away, so
+ * we're loosening restrictions. Errors of permission update are not
+ * fatal in this case, ignore them.
+ */
+ bdrv_refresh_perms(child_bs, NULL, NULL);
+
+ /*
+ * When the parent requiring a non-default AioContext is removed, the
+ * node moves back to the main AioContext
+ */
+ bdrv_try_change_aio_context(child_bs, qemu_get_aio_context(), NULL,
+ NULL);
+ }
- child_bs = child->bs;
- bdrv_detach_child(child);
bdrv_unref(child_bs);
}
return bdrv_set_file_or_backing_noperm(bs, backing_hd, true, tran, errp);
}
-int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
- Error **errp)
+int bdrv_set_backing_hd_drained(BlockDriverState *bs,
+ BlockDriverState *backing_hd,
+ Error **errp)
{
int ret;
Transaction *tran = tran_new();
GLOBAL_STATE_CODE();
- bdrv_drained_begin(bs);
+ assert(bs->quiesce_counter > 0);
ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp);
if (ret < 0) {
goto out;
}
- ret = bdrv_refresh_perms(bs, errp);
+ ret = bdrv_refresh_perms(bs, tran, errp);
out:
tran_finalize(tran, ret);
+ return ret;
+}
+
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+ Error **errp)
+{
+ int ret;
+ GLOBAL_STATE_CODE();
+ bdrv_drained_begin(bs);
+ ret = bdrv_set_backing_hd_drained(bs, backing_hd, errp);
bdrv_drained_end(bs);
return ret;
* returns a pointer to bs_queue, which is either the newly allocated
* bs_queue, or the existing bs_queue being used.
*
- * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
+ * bs is drained here and undrained by bdrv_reopen_queue_free().
+ *
+ * To be called with bs->aio_context locked.
*/
static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
BlockDriverState *bs,
int flags;
QemuOpts *opts;
- /* Make sure that the caller remembered to use a drained section. This is
- * important to avoid graph changes between the recursive queuing here and
- * bdrv_reopen_multiple(). */
- assert(bs->quiesce_counter > 0);
GLOBAL_STATE_CODE();
+ bdrv_drained_begin(bs);
+
if (bs_queue == NULL) {
bs_queue = g_new0(BlockReopenQueue, 1);
QTAILQ_INIT(bs_queue);
return bs_queue;
}
+/* To be called with bs->aio_context locked */
BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
BlockDriverState *bs,
QDict *options, bool keep_old_opts)
if (bs_queue) {
BlockReopenQueueEntry *bs_entry, *next;
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
+ AioContext *ctx = bdrv_get_aio_context(bs_entry->state.bs);
+
+ aio_context_acquire(ctx);
+ bdrv_drained_end(bs_entry->state.bs);
+ aio_context_release(ctx);
+
qobject_unref(bs_entry->state.explicit_options);
qobject_unref(bs_entry->state.options);
g_free(bs_entry);
BlockReopenQueueEntry *bs_entry, *next;
AioContext *ctx;
Transaction *tran = tran_new();
- g_autoptr(GHashTable) found = NULL;
g_autoptr(GSList) refresh_list = NULL;
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
bs_entry->prepared = true;
}
- found = g_hash_table_new(NULL, NULL);
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
BDRVReopenState *state = &bs_entry->state;
- refresh_list = bdrv_topological_dfs(refresh_list, found, state->bs);
+ refresh_list = g_slist_prepend(refresh_list, state->bs);
if (state->old_backing_bs) {
- refresh_list = bdrv_topological_dfs(refresh_list, found,
- state->old_backing_bs);
+ refresh_list = g_slist_prepend(refresh_list, state->old_backing_bs);
}
if (state->old_file_bs) {
- refresh_list = bdrv_topological_dfs(refresh_list, found,
- state->old_file_bs);
+ refresh_list = g_slist_prepend(refresh_list, state->old_file_bs);
}
}
GLOBAL_STATE_CODE();
- bdrv_subtree_drained_begin(bs);
+ queue = bdrv_reopen_queue(NULL, bs, opts, keep_old_opts);
+
if (ctx != qemu_get_aio_context()) {
aio_context_release(ctx);
}
-
- queue = bdrv_reopen_queue(NULL, bs, opts, keep_old_opts);
ret = bdrv_reopen_multiple(queue, errp);
if (ctx != qemu_get_aio_context()) {
aio_context_acquire(ctx);
}
- bdrv_subtree_drained_end(bs);
return ret;
}
}
if (child->bs) {
+ BlockDriverState *bs = child->bs;
+ bdrv_drained_begin(bs);
bdrv_replace_child_tran(child, NULL, tran);
+ bdrv_drained_end(bs);
}
tran_add(tran, &bdrv_remove_child_drv, child);
}
-/*
- * A function to remove backing-chain child of @bs if exists: cow child for
- * format nodes (always .backing) and filter child for filters (may be .file or
- * .backing)
- */
-static void bdrv_remove_filter_or_cow_child(BlockDriverState *bs,
- Transaction *tran)
+static void undrain_on_clean_cb(void *opaque)
{
- bdrv_remove_child(bdrv_filter_or_cow_child(bs), tran);
+ bdrv_drained_end(opaque);
}
+static TransactionActionDrv undrain_on_clean = {
+ .clean = undrain_on_clean_cb,
+};
+
static int bdrv_replace_node_noperm(BlockDriverState *from,
BlockDriverState *to,
bool auto_skip, Transaction *tran,
GLOBAL_STATE_CODE();
+ bdrv_drained_begin(from);
+ bdrv_drained_begin(to);
+ tran_add(tran, &undrain_on_clean, from);
+ tran_add(tran, &undrain_on_clean, to);
+
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
assert(c->bs == from);
if (!should_update_child(c, to)) {
Error **errp)
{
Transaction *tran = tran_new();
- g_autoptr(GHashTable) found = NULL;
g_autoptr(GSList) refresh_list = NULL;
BlockDriverState *to_cow_parent = NULL;
int ret;
}
if (detach_subchain) {
- bdrv_remove_filter_or_cow_child(to_cow_parent, tran);
+ bdrv_remove_child(bdrv_filter_or_cow_child(to_cow_parent), tran);
}
- found = g_hash_table_new(NULL, NULL);
-
- refresh_list = bdrv_topological_dfs(refresh_list, found, to);
- refresh_list = bdrv_topological_dfs(refresh_list, found, from);
+ refresh_list = g_slist_prepend(refresh_list, to);
+ refresh_list = g_slist_prepend(refresh_list, from);
ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp);
if (ret < 0) {
goto out;
}
- ret = bdrv_refresh_perms(bs_new, errp);
+ ret = bdrv_refresh_perms(bs_new, tran, errp);
out:
tran_finalize(tran, ret);
{
int ret;
Transaction *tran = tran_new();
- g_autoptr(GHashTable) found = NULL;
g_autoptr(GSList) refresh_list = NULL;
BlockDriverState *old_bs = child->bs;
bdrv_replace_child_tran(child, new_bs, tran);
- 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);
+ refresh_list = g_slist_prepend(refresh_list, old_bs);
+ refresh_list = g_slist_prepend(refresh_list, new_bs);
ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp);
BdrvCheckResult *res, BdrvCheckMode fix)
{
IO_CODE();
+ assert_bdrv_graph_readable();
if (bs->drv == NULL) {
return -ENOMEDIUM;
}
GLOBAL_STATE_CODE();
bdrv_ref(top);
- bdrv_subtree_drained_begin(top);
+ bdrv_drained_begin(base);
if (!top->drv || !base->drv) {
goto exit;
ret = 0;
exit:
- bdrv_subtree_drained_end(top);
+ bdrv_drained_end(base);
bdrv_unref(top);
return ret;
}
*/
if (bs->open_flags & BDRV_O_INACTIVE) {
bs->open_flags &= ~BDRV_O_INACTIVE;
- ret = bdrv_refresh_perms(bs, errp);
+ ret = bdrv_refresh_perms(bs, NULL, errp);
if (ret < 0) {
bs->open_flags |= BDRV_O_INACTIVE;
return ret;
IO_CODE();
assert(!(bs->open_flags & BDRV_O_INACTIVE));
+ assert_bdrv_graph_readable();
if (bs->drv->bdrv_co_invalidate_cache) {
bs->drv->bdrv_co_invalidate_cache(bs, &local_err);
* We only tried to loosen restrictions, so errors are not fatal, ignore
* them.
*/
- bdrv_refresh_perms(bs, NULL);
+ bdrv_refresh_perms(bs, NULL, NULL);
/* Recursively inactivate children */
QLIST_FOREACH(child, &bs->children, next) {
return true;
}
+/*
+ * Must not be called while holding the lock of an AioContext other than the
+ * current one.
+ */
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, bool quiet,
if (bs->quiesce_counter) {
aio_enable_external(bs->aio_context);
}
- assert_bdrv_graph_writable(bs);
bs->aio_context = NULL;
}
aio_disable_external(new_context);
}
- assert_bdrv_graph_writable(bs);
bs->aio_context = new_context;
if (bs->drv && bs->drv->bdrv_attach_aio_context) {
bs->walking_aio_notifiers = false;
}
-/*
- * Changes the AioContext used for fd handlers, timers, and BHs by this
- * BlockDriverState and all its children and parents.
- *
- * Must be called from the main AioContext.
- *
- * 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).
- *
- * @ignore will accumulate all visited BdrvChild objects. The caller is
- * responsible for freeing the list afterwards.
- */
-void bdrv_set_aio_context_ignore(BlockDriverState *bs,
- AioContext *new_context, GSList **ignore)
-{
- AioContext *old_context = bdrv_get_aio_context(bs);
- GSList *children_to_process = NULL;
- GSList *parents_to_process = NULL;
- GSList *entry;
- BdrvChild *child, *parent;
-
- g_assert(qemu_get_current_aio_context() == qemu_get_aio_context());
- GLOBAL_STATE_CODE();
-
- if (old_context == new_context) {
- return;
- }
-
- bdrv_drained_begin(bs);
-
- QLIST_FOREACH(child, &bs->children, next) {
- if (g_slist_find(*ignore, child)) {
- continue;
- }
- *ignore = g_slist_prepend(*ignore, child);
- children_to_process = g_slist_prepend(children_to_process, child);
- }
-
- QLIST_FOREACH(parent, &bs->parents, next_parent) {
- if (g_slist_find(*ignore, parent)) {
- continue;
- }
- *ignore = g_slist_prepend(*ignore, parent);
- parents_to_process = g_slist_prepend(parents_to_process, parent);
- }
-
- for (entry = children_to_process;
- entry != NULL;
- entry = g_slist_next(entry)) {
- child = entry->data;
- bdrv_set_aio_context_ignore(child->bs, new_context, ignore);
- }
- g_slist_free(children_to_process);
-
- for (entry = parents_to_process;
- entry != NULL;
- entry = g_slist_next(entry)) {
- parent = entry->data;
- assert(parent->klass->set_aio_ctx);
- parent->klass->set_aio_ctx(parent, new_context, ignore);
- }
- g_slist_free(parents_to_process);
-
- bdrv_detach_aio_context(bs);
-
- /* Acquire the new context, if necessary */
- if (qemu_get_aio_context() != new_context) {
- aio_context_acquire(new_context);
- }
-
- bdrv_attach_aio_context(bs, new_context);
-
- /*
- * If this function was recursively called from
- * bdrv_set_aio_context_ignore(), there may be nodes in the
- * subtree that have not yet been moved to the new AioContext.
- * Release the old one so bdrv_drained_end() can poll them.
- */
- if (qemu_get_aio_context() != old_context) {
- aio_context_release(old_context);
- }
-
- bdrv_drained_end(bs);
-
- if (qemu_get_aio_context() != old_context) {
- aio_context_acquire(old_context);
- }
- if (qemu_get_aio_context() != new_context) {
- aio_context_release(new_context);
- }
-}
-
-static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx,
- GSList **ignore, Error **errp)
-{
- GLOBAL_STATE_CODE();
- if (g_slist_find(*ignore, c)) {
- return true;
- }
- *ignore = g_slist_prepend(*ignore, c);
-
- /*
- * A BdrvChildClass that doesn't handle AioContext changes cannot
- * tolerate any AioContext changes
- */
- if (!c->klass->can_set_aio_ctx) {
- char *user = bdrv_child_user_desc(c);
- error_setg(errp, "Changing iothreads is not supported by %s", user);
- g_free(user);
- return false;
- }
- if (!c->klass->can_set_aio_ctx(c, ctx, ignore, errp)) {
- assert(!errp || *errp);
- return false;
- }
- return true;
-}
-
typedef struct BdrvStateSetAioContext {
AioContext *new_ctx;
BlockDriverState *bs;
return true;
}
-bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
- GSList **ignore, Error **errp)
-{
- GLOBAL_STATE_CODE();
- if (g_slist_find(*ignore, c)) {
- return true;
- }
- *ignore = g_slist_prepend(*ignore, c);
- return bdrv_can_set_aio_context(c->bs, ctx, ignore, errp);
-}
-
bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
GHashTable *visited, Transaction *tran,
Error **errp)
return bdrv_change_aio_context(c->bs, ctx, visited, tran, errp);
}
-/* @ignore will accumulate all visited BdrvChild object. The caller is
- * responsible for freeing the list afterwards. */
-bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
- GSList **ignore, Error **errp)
-{
- BdrvChild *c;
-
- if (bdrv_get_aio_context(bs) == ctx) {
- return true;
- }
-
- GLOBAL_STATE_CODE();
-
- QLIST_FOREACH(c, &bs->parents, next_parent) {
- if (!bdrv_parent_can_set_aio_context(c, ctx, ignore, errp)) {
- return false;
- }
- }
- QLIST_FOREACH(c, &bs->children, next) {
- if (!bdrv_child_can_set_aio_context(c, ctx, ignore, errp)) {
- return false;
- }
- }
-
- return true;
-}
-
static void bdrv_set_aio_context_clean(void *opaque)
{
BdrvStateSetAioContext *state = (BdrvStateSetAioContext *) opaque;
BlockDriverState *bs = (BlockDriverState *) state->bs;
AioContext *new_context = state->new_ctx;
AioContext *old_context = bdrv_get_aio_context(bs);
- assert_bdrv_graph_writable(bs);
/*
* Take the old AioContex when detaching it from bs.
return true;
}
-int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
- BdrvChild *ignore_child, Error **errp)
-{
- GSList *ignore;
- bool ret;
-
- GLOBAL_STATE_CODE();
-
- ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
- ret = bdrv_can_set_aio_context(bs, ctx, &ignore, errp);
- g_slist_free(ignore);
-
- if (!ret) {
- return -EPERM;
- }
-
- ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
- bdrv_set_aio_context_ignore(bs, ctx, &ignore);
- g_slist_free(ignore);
-
- return 0;
-}
-
/*
* Change bs's and recursively all of its parents' and children's AioContext
* to the given new context, returning an error if that isn't possible.
* bdrv_drained_end calls BDRV_POLL_WHILE that assumes the lock is taken too.
* Therefore the new AioContext lock must not be taken by the caller.
*/
-int bdrv_child_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
- BdrvChild *ignore_child, Error **errp)
+int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
+ BdrvChild *ignore_child, Error **errp)
{
Transaction *tran;
GHashTable *visited;
return 0;
}
-int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
- Error **errp)
-{
- GLOBAL_STATE_CODE();
- return bdrv_child_try_set_aio_context(bs, ctx, NULL, errp);
-}
-
void bdrv_add_aio_context_notifier(BlockDriverState *bs,
void (*attached_aio_context)(AioContext *new_context, void *opaque),
void (*detach_aio_context)(void *opaque), void *opaque)
projects / mirror_qemu.git / blobdiff