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block: Avoid bs->blk in bdrv_next()

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We need to introduce a separate BdrvNextIterator struct that can keep
more state than just the current BDS in order to avoid using the bs->blk
pointer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-03-22 18:58:50 +01:00
parent dde33812a8
commit 7c8eece45b
10 changed files with 103 additions and 76 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
block.c
View File

@ -2870,25 +2870,6 @@ BlockDriverState *bdrv_next_node(BlockDriverState *bs)
return QTAILQ_NEXT(bs, node_list);
}
/* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by
* the monitor or attached to a BlockBackend */
BlockDriverState *bdrv_next(BlockDriverState *bs)
{
if (!bs || bs->blk) {
bs = blk_next_root_bs(bs);
if (bs) {
return bs;
}
}
/* Ignore all BDSs that are attached to a BlockBackend here; they have been
* handled by the above block already */
do {
bs = bdrv_next_monitor_owned(bs);
} while (bs && bs->blk);
return bs;
}
const char *bdrv_get_node_name(const BlockDriverState *bs)
{
return bs->node_name;
@ -3220,10 +3201,11 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
void bdrv_invalidate_cache_all(Error **errp)
{
BlockDriverState *bs = NULL;
BlockDriverState *bs;
Error *local_err = NULL;
BdrvNextIterator *it = NULL;
while ((bs = bdrv_next(bs)) != NULL) {
while ((it = bdrv_next(it, &bs)) != NULL) {
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
@ -3265,10 +3247,11 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs,
int bdrv_inactivate_all(void)
{
BlockDriverState *bs = NULL;
BdrvNextIterator *it = NULL;
int ret = 0;
int pass;
while ((bs = bdrv_next(bs)) != NULL) {
while ((it = bdrv_next(it, &bs)) != NULL) {
aio_context_acquire(bdrv_get_aio_context(bs));
}
@ -3277,8 +3260,8 @@ 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++) {
bs = NULL;
while ((bs = bdrv_next(bs)) != NULL) {
it = NULL;
while ((it = bdrv_next(it, &bs)) != NULL) {
ret = bdrv_inactivate_recurse(bs, pass);
if (ret < 0) {
goto out;
@ -3287,8 +3270,8 @@ int bdrv_inactivate_all(void)
}
out:
bs = NULL;
while ((bs = bdrv_next(bs)) != NULL) {
it = NULL;
while ((it = bdrv_next(it, &bs)) != NULL) {
aio_context_release(bdrv_get_aio_context(bs));
}
@ -3781,10 +3764,11 @@ bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
*/
bool bdrv_is_first_non_filter(BlockDriverState *candidate)
{
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
/* walk down the bs forest recursively */
while ((bs = bdrv_next(bs)) != NULL) {
while ((it = bdrv_next(it, &bs)) != NULL) {
bool perm;
/* try to recurse in this top level bs */

74
block/block-backend.c
View File

@ -75,6 +75,7 @@ static const AIOCBInfo block_backend_aiocb_info = {
};
static void drive_info_del(DriveInfo *dinfo);
static BlockBackend *bdrv_first_blk(BlockDriverState *bs);
/* All BlockBackends */
static QTAILQ_HEAD(, BlockBackend) block_backends =
@ -286,28 +287,50 @@ BlockBackend *blk_next(BlockBackend *blk)
: QTAILQ_FIRST(&monitor_block_backends);
}
/*
* Iterates over all BlockDriverStates which are attached to a BlockBackend.
* This function is for use by bdrv_next().
*
* @bs must be NULL or a BDS that is attached to a BB.
*/
BlockDriverState *blk_next_root_bs(BlockDriverState *bs)
{
struct BdrvNextIterator {
enum {
BDRV_NEXT_BACKEND_ROOTS,
BDRV_NEXT_MONITOR_OWNED,
} phase;
BlockBackend *blk;
BlockDriverState *bs;
};
if (bs) {
assert(bs->blk);
blk = bs->blk;
} else {
blk = NULL;
/* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by
* the monitor or attached to a BlockBackend */
BdrvNextIterator *bdrv_next(BdrvNextIterator *it, BlockDriverState **bs)
{
if (!it) {
it = g_new(BdrvNextIterator, 1);
*it = (BdrvNextIterator) {
.phase = BDRV_NEXT_BACKEND_ROOTS,
};
}
do {
blk = blk_all_next(blk);
} while (blk && !blk->root);
/* First, return all root nodes of BlockBackends. In order to avoid
* returning a BDS twice when multiple BBs refer to it, we only return it
* if the BB is the first one in the parent list of the BDS. */
if (it->phase == BDRV_NEXT_BACKEND_ROOTS) {
do {
it->blk = blk_all_next(it->blk);
*bs = it->blk ? blk_bs(it->blk) : NULL;
} while (it->blk && (*bs == NULL || bdrv_first_blk(*bs) != it->blk));
return blk ? blk->root->bs : NULL;
if (*bs) {
return it;
}
it->phase = BDRV_NEXT_MONITOR_OWNED;
}
/* Then return the monitor-owned BDSes without a BB attached. Ignore all
* BDSes that are attached to a BlockBackend here; they have been handled
* by the above block already */
do {
it->bs = bdrv_next_monitor_owned(it->bs);
*bs = it->bs;
} while (*bs && bdrv_has_blk(*bs));
return *bs ? it : NULL;
}
/*
@ -394,21 +417,26 @@ BlockDriverState *blk_bs(BlockBackend *blk)
return blk->root ? blk->root->bs : NULL;
}
/*
* Returns true if @bs has an associated BlockBackend.
*/
bool bdrv_has_blk(BlockDriverState *bs)
static BlockBackend *bdrv_first_blk(BlockDriverState *bs)
{
BdrvChild *child;
QLIST_FOREACH(child, &bs->parents, next_parent) {
if (child->role == &child_root) {
assert(bs->blk);
return true;
return child->opaque;
}
}
assert(!bs->blk);
return false;
return NULL;
}
/*
* Returns true if @bs has an associated BlockBackend.
*/
bool bdrv_has_blk(BlockDriverState *bs)
{
return bdrv_first_blk(bs) != NULL;
}
/*

13
block/io.c
View File

@ -270,10 +270,11 @@ void bdrv_drain_all(void)
{
/* Always run first iteration so any pending completion BHs run */
bool busy = true;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
GSList *aio_ctxs = NULL, *ctx;
while ((bs = bdrv_next(bs))) {
while ((it = bdrv_next(it, &bs))) {
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
@ -301,10 +302,10 @@ void bdrv_drain_all(void)
for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
AioContext *aio_context = ctx->data;
bs = NULL;
it = NULL;
aio_context_acquire(aio_context);
while ((bs = bdrv_next(bs))) {
while ((it = bdrv_next(it, &bs))) {
if (aio_context == bdrv_get_aio_context(bs)) {
if (bdrv_requests_pending(bs)) {
busy = true;
@ -317,8 +318,8 @@ void bdrv_drain_all(void)
}
}
bs = NULL;
while ((bs = bdrv_next(bs))) {
it = NULL;
while ((it = bdrv_next(it, &bs))) {
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);

30
block/snapshot.c
View File

@ -373,9 +373,10 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
{
bool ok = true;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
while (ok && (bs = bdrv_next(bs))) {
while (ok && (it = bdrv_next(it, &bs))) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
@ -393,10 +394,11 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
Error **err)
{
int ret = 0;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
QEMUSnapshotInfo sn1, *snapshot = &sn1;
while (ret == 0 && (bs = bdrv_next(bs))) {
while (ret == 0 && (it = bdrv_next(it, &bs))) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
@ -415,9 +417,10 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs)
{
int err = 0;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
while (err == 0 && (bs = bdrv_next(bs))) {
while (err == 0 && (it = bdrv_next(it, &bs))) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
@ -435,9 +438,10 @@ int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
{
QEMUSnapshotInfo sn;
int err = 0;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
while (err == 0 && (bs = bdrv_next(bs))) {
while (err == 0 && (it = bdrv_next(it, &bs))) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
@ -457,9 +461,10 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState **first_bad_bs)
{
int err = 0;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
while (err == 0 && (bs = bdrv_next(bs))) {
while (err == 0 && (it = bdrv_next(it, &bs))) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
@ -480,9 +485,10 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *bdrv_all_find_vmstate_bs(void)
{
bool not_found = true;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
while (not_found && (bs = bdrv_next(bs))) {
while (not_found && (it = bdrv_next(it, &bs))) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);

3
blockdev.c
View File

@ -4135,8 +4135,9 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp)
{
BlockJobInfoList *head = NULL, **p_next = &head;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
while ((it = bdrv_next(it, &bs))) {
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);

3
include/block/block.h
View File

@ -17,6 +17,7 @@ typedef struct BlockJob BlockJob;
typedef struct BdrvChild BdrvChild;
typedef struct BdrvChildRole BdrvChildRole;
typedef struct BlockJobTxn BlockJobTxn;
typedef struct BdrvNextIterator BdrvNextIterator;
typedef struct BlockDriverInfo {
/* in bytes, 0 if irrelevant */
@ -401,7 +402,7 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
Error **errp);
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
BlockDriverState *bdrv_next_node(BlockDriverState *bs);
BlockDriverState *bdrv_next(BlockDriverState *bs);
BdrvNextIterator *bdrv_next(BdrvNextIterator *it, BlockDriverState **bs);
BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
int bdrv_is_encrypted(BlockDriverState *bs);
int bdrv_key_required(BlockDriverState *bs);

1
include/sysemu/block-backend.h
View File

@ -89,7 +89,6 @@ void blk_remove_all_bs(void);
const char *blk_name(BlockBackend *blk);
BlockBackend *blk_by_name(const char *name);
BlockBackend *blk_next(BlockBackend *blk);
BlockDriverState *blk_next_root_bs(BlockDriverState *bs);
bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
void monitor_remove_blk(BlockBackend *blk);

4
migration/block.c
View File

@ -383,6 +383,7 @@ static void init_blk_migration(QEMUFile *f)
BlockDriverState *bs;
BlkMigDevState *bmds;
int64_t sectors;
BdrvNextIterator *it = NULL;
block_mig_state.submitted = 0;
block_mig_state.read_done = 0;
@ -392,7 +393,8 @@ static void init_blk_migration(QEMUFile *f)
block_mig_state.bulk_completed = 0;
block_mig_state.zero_blocks = migrate_zero_blocks();
for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
while ((it = bdrv_next(it, &bs))) {
if (bdrv_is_read_only(bs)) {
continue;
}

6
monitor.c
View File

@ -3427,11 +3427,13 @@ void host_net_remove_completion(ReadLineState *rs, int nb_args, const char *str)
static void vm_completion(ReadLineState *rs, const char *str)
{
size_t len;
BlockDriverState *bs = NULL;
BlockDriverState *bs;
BdrvNextIterator *it = NULL;
len = strlen(str);
readline_set_completion_index(rs, len);
while ((bs = bdrv_next(bs))) {
while ((it = bdrv_next(it, &bs))) {
SnapshotInfoList *snapshots, *snapshot;
AioContext *ctx = bdrv_get_aio_context(bs);
bool ok = false;

5
qmp.c
View File

@ -181,6 +181,7 @@ void qmp_cont(Error **errp)
Error *local_err = NULL;
BlockBackend *blk;
BlockDriverState *bs;
BdrvNextIterator *it;
/* if there is a dump in background, we should wait until the dump
* finished */
@ -199,7 +200,9 @@ void qmp_cont(Error **errp)
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
blk_iostatus_reset(blk);
}
for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
it = NULL;
while ((it = bdrv_next(it, &bs))) {
bdrv_add_key(bs, NULL, &local_err);
if (local_err) {
error_propagate(errp, local_err);