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[Qemu-devel] [PATCH 7/9] block: Avoid bs->blk in bdrv_next()
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 7/9] block: Avoid bs->blk in bdrv_next() |
Date: |
Tue, 22 Mar 2016 20:36:35 +0100 |
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 <address@hidden>
---
block.c | 34 +++++++++-----------------------
block/block-backend.c | 44 +++++++++++++++++++++++++++---------------
block/io.c | 13 +++++++------
block/snapshot.c | 30 ++++++++++++++++------------
blockdev.c | 3 ++-
include/block/block.h | 3 ++-
include/sysemu/block-backend.h | 1 -
migration/block.c | 4 +++-
monitor.c | 6 ++++--
qmp.c | 5 ++++-
10 files changed, 77 insertions(+), 66 deletions(-)
diff --git a/block.c b/block.c
index 3770fb0..eefbcf3 100644
--- a/block.c
+++ b/block.c
@@ -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 || bdrv_has_blk(bs)) {
- 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 && bdrv_has_blk(bs));
- return bs;
-}
-
const char *bdrv_get_node_name(const BlockDriverState *bs)
{
return bs->node_name;
@@ -3212,10 +3193,11 @@ 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);
@@ -3245,10 +3227,11 @@ static int bdrv_inactivate(BlockDriverState *bs)
int bdrv_inactivate_all(void)
{
- BlockDriverState *bs = NULL;
+ BlockDriverState *bs;
+ BdrvNextIterator *it = NULL;
int ret;
- 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);
@@ -3748,10 +3731,11 @@ 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 */
diff --git a/block/block-backend.c b/block/block-backend.c
index fdd1727..b71b822 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -325,28 +325,40 @@ 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 {
+ int 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_new0(BdrvNextIterator, 1);
+ }
+
+ if (it->phase == 0) {
+ do {
+ it->blk = blk_all_next(it->blk);
+ *bs = it->blk ? blk_bs(it->blk) : NULL;
+ } while (it->blk && *bs == NULL);
+
+ if (*bs) {
+ return it;
+ }
+ it->phase = 1;
}
+ /* Ignore all BDSs that are attached to a BlockBackend here; they have been
+ * handled by the above block already */
do {
- blk = blk_all_next(blk);
- } while (blk && !blk->root);
+ it->bs = bdrv_next_monitor_owned(it->bs);
+ *bs = it->bs;
+ } while (*bs && bdrv_has_blk(*bs));
- return blk ? blk->root->bs : NULL;
+ return *bs ? it : NULL;
}
/*
diff --git a/block/io.c b/block/io.c
index 6ec133f..ead65cd 100644
--- a/block/io.c
+++ b/block/io.c
@@ -213,10 +213,11 @@ 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);
@@ -242,10 +243,10 @@ 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_flush_io_queue(bs)) {
busy = true;
@@ -261,8 +262,8 @@ 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);
diff --git a/block/snapshot.c b/block/snapshot.c
index 17a27b5..6eb0371 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -372,9 +372,10 @@ 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);
@@ -392,10 +393,11 @@ 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);
@@ -414,9 +416,10 @@ 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);
@@ -434,9 +437,10 @@ 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);
@@ -456,9 +460,10 @@ 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);
@@ -479,9 +484,10 @@ 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);
diff --git a/blockdev.c b/blockdev.c
index 99657d0..c59cf3e 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -4073,8 +4073,9 @@ 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);
diff --git a/include/block/block.h b/include/block/block.h
index c2d1456..2bafd32 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -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 */
@@ -398,7 +399,7 @@ 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);
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index bd68a17..4e066a2 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -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);
diff --git a/migration/block.c b/migration/block.c
index 72883d7..973e62a 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -381,6 +381,7 @@ 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;
@@ -390,7 +391,8 @@ 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;
}
diff --git a/monitor.c b/monitor.c
index 4c02f0f..ad0fee5 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3426,11 +3426,13 @@ 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;
diff --git a/qmp.c b/qmp.c
index 3f16a77..0636156 100644
--- a/qmp.c
+++ b/qmp.c
@@ -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);
--
1.8.3.1
- [Qemu-devel] [PATCH 1/9] block: Use BdrvChild callbacks for change_media/resize, (continued)
- [Qemu-devel] [PATCH 1/9] block: Use BdrvChild callbacks for change_media/resize, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 5/9] block: Avoid BDS.blk in bdrv_next(), Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 6/9] block: Remove bdrv_move_feature_fields(), Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 3/9] block jobs: Use BdrvChild callbacks for iostatus operations, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 8/9] block: Don't return throttling info in query-named-block-nodes, Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 7/9] block: Avoid bs->blk in bdrv_next(),
Kevin Wolf <=
- [Qemu-devel] [PATCH 4/9] block: Remove bdrv_aio_multiwrite(), Kevin Wolf, 2016/03/22
- [Qemu-devel] [PATCH 9/9] block: Remove BlockDriverState.blk, Kevin Wolf, 2016/03/22
- Re: [Qemu-devel] [PATCH 0/9] block: Remove BlockDriverState.blk, Paolo Bonzini, 2016/03/22