* [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD
@ 2014-02-23 1:54 Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 01/14] block: Add BlockOpType enum Fam Zheng
` (13 more replies)
0 siblings, 14 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This series adds for point-in-time snapshot NBD exporting based on
blockdev-backup (variant of drive-backup with existing device as target).
We get a thin point-in-time snapshot by COW mechanism of drive-backup, and
export it through built in NBD server. The steps are as below:
1. (SHELL) qemu-img create -f qcow2 BACKUP.qcow2 <source size here>
(Alternatively we can use -o backing_file=RUNNING-VM.img to omit explicitly
providing the size by ourselves, but it's risky because RUNNING-VM.qcow2 is
used r/w by guest. Whether or not setting backing file in the image file
doesn't matter, as we are going to override the backing hd in the next
step)
2. (QMP) blockdev-add backing=source-drive file.driver=file file.filename=BACKUP.qcow2 id=target0 if=none driver=qcow2
(where source-drive is the running BlockDriverState name for
RUNNING-VM.img. This patch implements "backing=" option to override
backing_hd for added drive)
3. (QMP) blockdev-backup device=source-drive sync=none target=target0
(this is the QMP command introduced by this series, which use a named
device as target of drive-backup)
4. (QMP) nbd-server-add device=target0
When image fleecing done:
1. (QMP) block-job-cancel device=source-drive
2. (HMP) drive_del target0
3. (SHELL) rm BACKUP.qcow2
v15: Rebase onto Kevin's PULL request.
Add Benoit's rev-by for 1~4.
Address Jeff's comments (thanks for reviewing!):
[05/14] block: Add bdrv_set_backing_hd()
bdrv_ref new backing before bdrv_unref the old one.
Fix refcnt of backing_hd in bdrv_open_backing_file.
Use bdrv_set_backing_hd in bdrv_append.
[06/14] block: Add backing_blocker in BlockDriverState
Fix mirror.
[07/14] block: Parse "backing" option to reference existing BDS
[08/14] block: Support dropping active in bdrv_drop_intermediate
Avoid bdrv_swap for middle change.
Fix comment.
Fix commit by finding overlay before dropping intermediate.
[14/14] qemu-iotests: Image fleecing test case 083
Rename 081 -> 083.
Fam Zheng (14):
block: Add BlockOpType enum
block: Introduce op_blockers to BlockDriverState
block: Replace in_use with operation blocker
block: Move op_blocker check from block_job_create to its caller
block: Add bdrv_set_backing_hd()
block: Add backing_blocker in BlockDriverState
block: Parse "backing" option to reference existing BDS
block: Support dropping active in bdrv_drop_intermediate
stream: Use bdrv_drop_intermediate and drop close_unused_images
qmp: Add command 'blockdev-backup'
block: Allow backup on referenced named BlockDriverState
block: Add blockdev-backup to transaction
qemu-iotests: Test blockdev-backup in 055
qemu-iotests: Image fleecing test case 083
block-migration.c | 7 +-
block.c | 313 ++++++++++++++++++++++++++--------------
block/backup.c | 26 ++++
block/commit.c | 2 +-
block/mirror.c | 1 +
block/stream.c | 30 +---
blockdev.c | 118 +++++++++++++--
blockjob.c | 14 +-
hw/block/dataplane/virtio-blk.c | 19 ++-
include/block/block.h | 29 +++-
include/block/block_int.h | 9 +-
include/block/blockjob.h | 3 +
qapi-schema.json | 50 +++++++
qmp-commands.hx | 44 ++++++
tests/qemu-iotests/055 | 275 +++++++++++++++++++++++++++++------
tests/qemu-iotests/055.out | 4 +-
tests/qemu-iotests/083 | 99 +++++++++++++
tests/qemu-iotests/083.out | 5 +
tests/qemu-iotests/group | 1 +
19 files changed, 844 insertions(+), 205 deletions(-)
create mode 100755 tests/qemu-iotests/083
create mode 100644 tests/qemu-iotests/083.out
--
1.8.5.4
^ permalink raw reply [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 01/14] block: Add BlockOpType enum
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 02/14] block: Introduce op_blockers to BlockDriverState Fam Zheng
` (12 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This adds the enum of all the operations that can be taken on a block
device.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
---
include/block/block.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/block/block.h b/include/block/block.h
index 780f48b..8820735 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -154,6 +154,25 @@ typedef struct BDRVReopenState {
void *opaque;
} BDRVReopenState;
+/*
+ * Block operation types
+ */
+typedef enum BlockOpType {
+ BLOCK_OP_TYPE_BACKUP_SOURCE,
+ BLOCK_OP_TYPE_BACKUP_TARGET,
+ BLOCK_OP_TYPE_CHANGE,
+ BLOCK_OP_TYPE_COMMIT,
+ BLOCK_OP_TYPE_DATAPLANE,
+ BLOCK_OP_TYPE_DRIVE_DEL,
+ BLOCK_OP_TYPE_EJECT,
+ BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
+ BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
+ BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+ BLOCK_OP_TYPE_MIRROR,
+ BLOCK_OP_TYPE_RESIZE,
+ BLOCK_OP_TYPE_STREAM,
+ BLOCK_OP_TYPE_MAX,
+} BlockOpType;
void bdrv_iostatus_enable(BlockDriverState *bs);
void bdrv_iostatus_reset(BlockDriverState *bs);
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 02/14] block: Introduce op_blockers to BlockDriverState
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 01/14] block: Add BlockOpType enum Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker Fam Zheng
` (11 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
BlockDriverState.op_blockers is an array of lists with BLOCK_OP_TYPE_MAX
elements. Each list is a list of blockers of an operation type
(BlockOpType), that marks this BDS as currently blocked for a certain
type of operation with reason errors stored in the list. The rule of
usage is:
* BDS user who wants to take an operation should check if there's any
blocker of the type with bdrv_op_is_blocked().
* BDS user who wants to block certain types of operation, should call
bdrv_op_block (or bdrv_op_block_all to block all types of operations,
which is similar to the existing bdrv_set_in_use()).
* A blocker is only referenced by op_blockers, so the lifecycle is
managed by caller, and shouldn't be lost until unblock, so typically
a caller does these:
- Allocate a blocker with error_setg or similar, call bdrv_op_block()
to block some operations.
- Hold the blocker, do his job.
- Unblock operations that it blocked, with the same reason pointer
passed to bdrv_op_unblock().
- Release the blocker with error_free().
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
---
block.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++
include/block/block.h | 7 +++++
include/block/block_int.h | 5 ++++
3 files changed, 87 insertions(+)
diff --git a/block.c b/block.c
index 2fd5482..0a2e840 100644
--- a/block.c
+++ b/block.c
@@ -335,6 +335,7 @@ void bdrv_register(BlockDriver *bdrv)
BlockDriverState *bdrv_new(const char *device_name)
{
BlockDriverState *bs;
+ int i;
bs = g_malloc0(sizeof(BlockDriverState));
QLIST_INIT(&bs->dirty_bitmaps);
@@ -342,6 +343,9 @@ BlockDriverState *bdrv_new(const char *device_name)
if (device_name[0] != '\0') {
QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list);
}
+ for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+ QLIST_INIT(&bs->op_blockers[i]);
+ }
bdrv_iostatus_disable(bs);
notifier_list_init(&bs->close_notifiers);
notifier_with_return_list_init(&bs->before_write_notifiers);
@@ -1851,6 +1855,8 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
* We do want to swap name but don't want to swap linked list entries
*/
bs_dest->node_list = bs_src->node_list;
+ memcpy(bs_dest->op_blockers, bs_src->op_blockers,
+ sizeof(bs_dest->op_blockers));
}
/*
@@ -5130,6 +5136,75 @@ void bdrv_unref(BlockDriverState *bs)
}
}
+struct BdrvOpBlocker {
+ Error *reason;
+ QLIST_ENTRY(BdrvOpBlocker) list;
+};
+
+bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
+{
+ BdrvOpBlocker *blocker;
+ assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
+ if (!QLIST_EMPTY(&bs->op_blockers[op])) {
+ blocker = QLIST_FIRST(&bs->op_blockers[op]);
+ if (errp) {
+ *errp = error_copy(blocker->reason);
+ }
+ return true;
+ }
+ return false;
+}
+
+void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
+{
+ BdrvOpBlocker *blocker;
+ assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
+
+ blocker = g_malloc0(sizeof(BdrvOpBlocker));
+ blocker->reason = reason;
+ QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
+}
+
+void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
+{
+ BdrvOpBlocker *blocker, *next;
+ assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
+ QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
+ if (blocker->reason == reason) {
+ QLIST_REMOVE(blocker, list);
+ g_free(blocker);
+ }
+ }
+}
+
+void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
+{
+ int i;
+ for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+ bdrv_op_block(bs, i, reason);
+ }
+}
+
+void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
+{
+ int i;
+ for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+ bdrv_op_unblock(bs, i, reason);
+ }
+}
+
+bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
+{
+ int i;
+
+ for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+ if (!QLIST_EMPTY(&bs->op_blockers[i])) {
+ return false;
+ }
+ }
+ return true;
+}
+
void bdrv_set_in_use(BlockDriverState *bs, int in_use)
{
assert(bs->in_use != in_use);
diff --git a/include/block/block.h b/include/block/block.h
index 8820735..4874e2a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -474,6 +474,13 @@ void bdrv_unref(BlockDriverState *bs);
void bdrv_set_in_use(BlockDriverState *bs, int in_use);
int bdrv_in_use(BlockDriverState *bs);
+bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
+void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
+void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
+void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
+void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
+bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
+
#ifdef CONFIG_LINUX_AIO
int raw_get_aio_fd(BlockDriverState *bs);
#else
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 0bcf1c9..4e558d0 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -270,6 +270,8 @@ typedef struct BlockLimits {
size_t opt_mem_alignment;
} BlockLimits;
+typedef struct BdrvOpBlocker BdrvOpBlocker;
+
/*
* Note: the function bdrv_append() copies and swaps contents of
* BlockDriverStates, so if you add new fields to this struct, please
@@ -361,6 +363,9 @@ struct BlockDriverState {
QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
+ /* operation blockers */
+ QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
+
/* long-running background operation */
BlockJob *job;
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 01/14] block: Add BlockOpType enum Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 02/14] block: Introduce op_blockers to BlockDriverState Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-27 12:12 ` Markus Armbruster
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 04/14] block: Move op_blocker check from block_job_create to its caller Fam Zheng
` (10 subsequent siblings)
13 siblings, 1 reply; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This drops BlockDriverState.in_use with op_blockers:
- Call bdrv_op_block_all in place of bdrv_set_in_use(bs, 1).
- Call bdrv_op_unblock_all in place of bdrv_set_in_use(bs, 0).
- Check bdrv_op_is_blocked() in place of bdrv_in_use(bs).
The specific types are used, e.g. in place of starting block backup,
bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP, ...).
- Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use).
Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers at
this moment. So although the checks are specific to op types, this
changes can still be seen as identical logic with previously with
in_use. The difference is error message are improved because of blocker
error info.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
---
block-migration.c | 7 +++++--
block.c | 24 +++++++-----------------
blockdev.c | 15 ++++++---------
blockjob.c | 14 +++++++++-----
hw/block/dataplane/virtio-blk.c | 19 ++++++++++++-------
include/block/block.h | 2 --
include/block/block_int.h | 1 -
include/block/blockjob.h | 3 +++
8 files changed, 42 insertions(+), 43 deletions(-)
diff --git a/block-migration.c b/block-migration.c
index 897fdba..bf9a25f 100644
--- a/block-migration.c
+++ b/block-migration.c
@@ -59,6 +59,7 @@ typedef struct BlkMigDevState {
unsigned long *aio_bitmap;
int64_t completed_sectors;
BdrvDirtyBitmap *dirty_bitmap;
+ Error *blocker;
} BlkMigDevState;
typedef struct BlkMigBlock {
@@ -346,7 +347,8 @@ static void init_blk_migration_it(void *opaque, BlockDriverState *bs)
bmds->completed_sectors = 0;
bmds->shared_base = block_mig_state.shared_base;
alloc_aio_bitmap(bmds);
- bdrv_set_in_use(bs, 1);
+ error_setg(&bmds->blocker, "block device is in use by migration");
+ bdrv_op_block_all(bs, bmds->blocker);
bdrv_ref(bs);
block_mig_state.total_sector_sum += sectors;
@@ -584,7 +586,8 @@ static void blk_mig_cleanup(void)
blk_mig_lock();
while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
- bdrv_set_in_use(bmds->bs, 0);
+ bdrv_op_unblock_all(bmds->bs, bmds->blocker);
+ error_free(bmds->blocker);
bdrv_unref(bmds->bs);
g_free(bmds->aio_bitmap);
g_free(bmds);
diff --git a/block.c b/block.c
index 0a2e840..684b9d6 100644
--- a/block.c
+++ b/block.c
@@ -1843,7 +1843,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
bs_dest->refcnt = bs_src->refcnt;
/* job */
- bs_dest->in_use = bs_src->in_use;
bs_dest->job = bs_src->job;
/* keep the same entry in bdrv_states */
@@ -1880,7 +1879,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
assert(bs_new->job == NULL);
assert(bs_new->dev == NULL);
- assert(bs_new->in_use == 0);
+ assert(bdrv_op_blocker_is_empty(bs_new));
assert(bs_new->io_limits_enabled == false);
assert(!throttle_have_timer(&bs_new->throttle_state));
@@ -1899,7 +1898,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
/* Check a few fields that should remain attached to the device */
assert(bs_new->dev == NULL);
assert(bs_new->job == NULL);
- assert(bs_new->in_use == 0);
+ assert(bdrv_op_blocker_is_empty(bs_new));
assert(bs_new->io_limits_enabled == false);
assert(!throttle_have_timer(&bs_new->throttle_state));
@@ -1936,7 +1935,7 @@ static void bdrv_delete(BlockDriverState *bs)
{
assert(!bs->dev);
assert(!bs->job);
- assert(!bs->in_use);
+ assert(bdrv_op_blocker_is_empty(bs));
assert(!bs->refcnt);
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
@@ -2118,7 +2117,8 @@ int bdrv_commit(BlockDriverState *bs)
return -ENOTSUP;
}
- if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, NULL) ||
+ bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, NULL)) {
return -EBUSY;
}
@@ -3353,8 +3353,9 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
return -ENOTSUP;
if (bs->read_only)
return -EACCES;
- if (bdrv_in_use(bs))
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
return -EBUSY;
+ }
ret = drv->bdrv_truncate(bs, offset);
if (ret == 0) {
ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
@@ -5205,17 +5206,6 @@ bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
return true;
}
-void bdrv_set_in_use(BlockDriverState *bs, int in_use)
-{
- assert(bs->in_use != in_use);
- bs->in_use = in_use;
-}
-
-int bdrv_in_use(BlockDriverState *bs)
-{
- return bs->in_use;
-}
-
void bdrv_iostatus_enable(BlockDriverState *bs)
{
bs->iostatus_enabled = true;
diff --git a/blockdev.c b/blockdev.c
index 357f760..5c5a9c4 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1293,8 +1293,8 @@ static void external_snapshot_prepare(BlkTransactionState *common,
return;
}
- if (bdrv_in_use(state->old_bs)) {
- error_set(errp, QERR_DEVICE_IN_USE, device);
+ if (bdrv_op_is_blocked(state->old_bs,
+ BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) {
return;
}
@@ -1516,8 +1516,7 @@ exit:
static void eject_device(BlockDriverState *bs, int force, Error **errp)
{
- if (bdrv_in_use(bs)) {
- error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
return;
}
if (!bdrv_dev_has_removable_media(bs)) {
@@ -1723,7 +1722,7 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
qerror_report(QERR_DEVICE_NOT_FOUND, id);
return -1;
}
- if (bdrv_in_use(bs)) {
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, NULL)) {
qerror_report(QERR_DEVICE_IN_USE, id);
return -1;
}
@@ -1976,8 +1975,7 @@ void qmp_drive_backup(const char *device, const char *target,
}
}
- if (bdrv_in_use(bs)) {
- error_set(errp, QERR_DEVICE_IN_USE, device);
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
return;
}
@@ -2110,8 +2108,7 @@ void qmp_drive_mirror(const char *device, const char *target,
}
}
- if (bdrv_in_use(bs)) {
- error_set(errp, QERR_DEVICE_IN_USE, device);
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR, errp)) {
return;
}
diff --git a/blockjob.c b/blockjob.c
index b3ce14c..f643a78 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -41,14 +41,16 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
{
BlockJob *job;
- if (bs->job || bdrv_in_use(bs)) {
+ if (bs->job || !bdrv_op_blocker_is_empty(bs)) {
error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
return NULL;
}
bdrv_ref(bs);
- bdrv_set_in_use(bs, 1);
-
job = g_malloc0(driver->instance_size);
+ error_setg(&job->blocker, "block device is in use by block job: %s",
+ BlockJobType_lookup[driver->job_type]);
+ bdrv_op_block_all(bs, job->blocker);
+
job->driver = driver;
job->bs = bs;
job->cb = cb;
@@ -63,8 +65,9 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
block_job_set_speed(job, speed, &local_err);
if (local_err) {
bs->job = NULL;
+ bdrv_op_unblock_all(bs, job->blocker);
+ error_free(job->blocker);
g_free(job);
- bdrv_set_in_use(bs, 0);
error_propagate(errp, local_err);
return NULL;
}
@@ -79,8 +82,9 @@ void block_job_completed(BlockJob *job, int ret)
assert(bs->job == job);
job->cb(job->opaque, ret);
bs->job = NULL;
+ bdrv_op_unblock_all(bs, job->blocker);
+ error_free(job->blocker);
g_free(job);
- bdrv_set_in_use(bs, 0);
}
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 2237edb..cee0aa5 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -69,6 +69,9 @@ struct VirtIOBlockDataPlane {
queue */
unsigned int num_reqs;
+
+ /* Operation blocker on BDS */
+ Error *blocker;
};
/* Raise an interrupt to signal guest, if necessary */
@@ -368,6 +371,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
{
VirtIOBlockDataPlane *s;
int fd;
+ Error *local_err = NULL;
*dataplane = NULL;
@@ -390,9 +394,10 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
/* If dataplane is (re-)enabled while the guest is running there could be
* block jobs that can conflict.
*/
- if (bdrv_in_use(blk->conf.bs)) {
- error_setg(errp,
- "cannot start dataplane thread while device is in use");
+ if (bdrv_op_is_blocked(blk->conf.bs, BLOCK_OP_TYPE_DATAPLANE, &local_err)) {
+ error_report("cannot start dataplane thread: %s",
+ error_get_pretty(local_err));
+ error_free(local_err);
return;
}
@@ -407,9 +412,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
s->vdev = vdev;
s->fd = fd;
s->blk = blk;
-
- /* Prevent block operations that conflict with data plane thread */
- bdrv_set_in_use(blk->conf.bs, 1);
+ error_setg(&s->blocker, "block device is in use by data plane");
+ bdrv_op_block_all(blk->conf.bs, s->blocker);
*dataplane = s;
}
@@ -421,7 +425,8 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
}
virtio_blk_data_plane_stop(s);
- bdrv_set_in_use(s->blk->conf.bs, 0);
+ bdrv_op_unblock_all(s->blk->conf.bs, s->blocker);
+ error_free(s->blocker);
g_free(s);
}
diff --git a/include/block/block.h b/include/block/block.h
index 4874e2a..a46f70a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -471,8 +471,6 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs);
void bdrv_ref(BlockDriverState *bs);
void bdrv_unref(BlockDriverState *bs);
-void bdrv_set_in_use(BlockDriverState *bs, int in_use);
-int bdrv_in_use(BlockDriverState *bs);
bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 4e558d0..1d3f76f 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -359,7 +359,6 @@ struct BlockDriverState {
QTAILQ_ENTRY(BlockDriverState) device_list;
QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
int refcnt;
- int in_use; /* users other than guest access, eg. block migration */
QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index d76de62..c0a7875 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -106,6 +106,9 @@ struct BlockJob {
/** The completion function that will be called when the job completes. */
BlockDriverCompletionFunc *cb;
+ /** Block other operations when block job is running */
+ Error *blocker;
+
/** The opaque value that is passed to the completion function. */
void *opaque;
};
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 04/14] block: Move op_blocker check from block_job_create to its caller
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (2 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd() Fam Zheng
` (9 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
It makes no sense to check for "any" blocker on bs, we are here only
because of the mechanical conversion from in_use to op_blockers. Remove
it now, and let the callers check specific operation types. Backup and
mirror already have it, add checker to stream and commit.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
---
blockdev.c | 8 ++++++++
blockjob.c | 2 +-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/blockdev.c b/blockdev.c
index 5c5a9c4..2fdf259 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1844,6 +1844,10 @@ void qmp_block_stream(const char *device, bool has_base,
return;
}
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_STREAM, errp)) {
+ return;
+ }
+
if (base) {
base_bs = bdrv_find_backing_image(bs, base);
if (base_bs == NULL) {
@@ -1884,6 +1888,10 @@ void qmp_block_commit(const char *device,
return;
}
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, errp)) {
+ return;
+ }
+
/* default top_bs is the active layer */
top_bs = bs;
diff --git a/blockjob.c b/blockjob.c
index f643a78..3e33051 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -41,7 +41,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
{
BlockJob *job;
- if (bs->job || !bdrv_op_blocker_is_empty(bs)) {
+ if (bs->job) {
error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
return NULL;
}
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd()
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (3 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 04/14] block: Move op_blocker check from block_job_create to its caller Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-26 21:45 ` Jeff Cody
2014-02-26 22:35 ` Jeff Cody
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 06/14] block: Add backing_blocker in BlockDriverState Fam Zheng
` (8 subsequent siblings)
13 siblings, 2 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This is the common but non-trivial steps to assign or change the
backing_hd of BDS.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block.c | 46 ++++++++++++++++++++++++++++++++++++++--------
include/block/block.h | 1 +
2 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/block.c b/block.c
index 684b9d6..9caade9 100644
--- a/block.c
+++ b/block.c
@@ -1041,6 +1041,32 @@ fail:
return ret;
}
+void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
+{
+ if (backing_hd) {
+ /* Grab the reference before unref original backing_hd, so we are safe
+ * when rebasing in the backing chain.
+ */
+ bdrv_ref(backing_hd);
+ }
+
+ if (bs->backing_hd) {
+ bdrv_unref(bs->backing_hd);
+ }
+
+ bs->backing_hd = backing_hd;
+ if (!backing_hd) {
+ bs->backing_file[0] = '\0';
+ bs->backing_format[0] = '\0';
+ goto out;
+ }
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
+ pstrcpy(bs->backing_format, sizeof(bs->backing_format),
+ backing_hd->drv ? backing_hd->drv->format_name : "");
+out:
+ bdrv_refresh_limits(bs);
+}
+
/*
* Opens the backing file for a BlockDriverState if not yet open
*
@@ -1054,6 +1080,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
char backing_filename[PATH_MAX];
int back_flags, ret;
BlockDriver *back_drv = NULL;
+ BlockDriverState *backing_hd;
Error *local_err = NULL;
if (bs->backing_hd != NULL) {
@@ -1077,6 +1104,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
sizeof(backing_filename));
}
+ backing_hd = bdrv_new("");
+
if (bs->backing_format[0] != '\0') {
back_drv = bdrv_find_format(bs->backing_format);
}
@@ -1085,23 +1114,24 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT |
BDRV_O_COPY_ON_READ);
- assert(bs->backing_hd == NULL);
- ret = bdrv_open(&bs->backing_hd,
+ ret = bdrv_open(&backing_hd,
*backing_filename ? backing_filename : NULL, NULL, options,
back_flags, back_drv, &local_err);
if (ret < 0) {
bs->backing_hd = NULL;
+ bdrv_unref(backing_hd);
+ backing_hd = NULL;
bs->open_flags |= BDRV_O_NO_BACKING;
error_setg(errp, "Could not open backing file: %s",
error_get_pretty(local_err));
error_free(local_err);
return ret;
}
-
- if (bs->backing_hd->file) {
- pstrcpy(bs->backing_file, sizeof(bs->backing_file),
- bs->backing_hd->file->filename);
- }
+ bdrv_set_backing_hd(bs, backing_hd);
+ /* Now we have refcnt = 2 on backing_hd by bdrv_new and
+ * bdrv_set_backing_hd, while we only need 1 */
+ assert(backing_hd->refcnt == 2);
+ bdrv_unref(backing_hd);
/* Recalculate the BlockLimits with the backing file */
bdrv_refresh_limits(bs);
@@ -1923,7 +1953,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
/* The contents of 'tmp' will become bs_top, as we are
* swapping bs_new and bs_top contents. */
- bs_top->backing_hd = bs_new;
+ bdrv_set_backing_hd(bs_top, bs_new);
bs_top->open_flags &= ~BDRV_O_NO_BACKING;
pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file),
bs_new->filename);
diff --git a/include/block/block.h b/include/block/block.h
index a46f70a..ee1582d 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -208,6 +208,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags);
int bdrv_open_image(BlockDriverState **pbs, const char *filename,
QDict *options, const char *bdref_key, int flags,
bool allow_none, Error **errp);
+void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp);
int bdrv_open(BlockDriverState **pbs, const char *filename,
const char *reference, QDict *options, int flags,
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 06/14] block: Add backing_blocker in BlockDriverState
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (4 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd() Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 07/14] block: Parse "backing" option to reference existing BDS Fam Zheng
` (7 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This makes use of op_blocker and blocks all the operations except for
commit target, on each BlockDriverState->backing_hd.
The asserts for op_blocker in bdrv_swap are removed because with this
change, the target of block commit has at least the backing blocker of
its child, so the assertion is not true. Callers should do their check.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block.c | 19 +++++++++++++++----
block/mirror.c | 1 +
include/block/block_int.h | 3 +++
3 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/block.c b/block.c
index 9caade9..edfbe59 100644
--- a/block.c
+++ b/block.c
@@ -1051,18 +1051,32 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
}
if (bs->backing_hd) {
+ assert(error_is_set(&bs->backing_blocker));
+ bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker);
bdrv_unref(bs->backing_hd);
+ } else if (backing_hd) {
+ error_setg(&bs->backing_blocker,
+ "device is used as backing hd of '%s'",
+ bs->device_name);
}
bs->backing_hd = backing_hd;
if (!backing_hd) {
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
+ if (error_is_set(&bs->backing_blocker)) {
+ error_free(bs->backing_blocker);
+ }
goto out;
}
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
pstrcpy(bs->backing_format, sizeof(bs->backing_format),
backing_hd->drv ? backing_hd->drv->format_name : "");
+
+ bdrv_op_block_all(bs->backing_hd, bs->backing_blocker);
+ /* Otherwise we won't be able to commit due to check in bdrv_commit */
+ bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT,
+ bs->backing_blocker);
out:
bdrv_refresh_limits(bs);
}
@@ -1706,8 +1720,7 @@ void bdrv_close(BlockDriverState *bs)
if (bs->drv) {
if (bs->backing_hd) {
- bdrv_unref(bs->backing_hd);
- bs->backing_hd = NULL;
+ bdrv_set_backing_hd(bs, NULL);
}
bs->drv->bdrv_close(bs);
g_free(bs->opaque);
@@ -1909,7 +1922,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
assert(bs_new->job == NULL);
assert(bs_new->dev == NULL);
- assert(bdrv_op_blocker_is_empty(bs_new));
assert(bs_new->io_limits_enabled == false);
assert(!throttle_have_timer(&bs_new->throttle_state));
@@ -1928,7 +1940,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
/* Check a few fields that should remain attached to the device */
assert(bs_new->dev == NULL);
assert(bs_new->job == NULL);
- assert(bdrv_op_blocker_is_empty(bs_new));
assert(bs_new->io_limits_enabled == false);
assert(!throttle_have_timer(&bs_new->throttle_state));
diff --git a/block/mirror.c b/block/mirror.c
index e683959..a414033 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -487,6 +487,7 @@ immediate_exit:
* trigger the unref from the top one */
BlockDriverState *p = s->base->backing_hd;
s->base->backing_hd = NULL;
+ bdrv_op_unblock_all(p, s->base->backing_blocker);
bdrv_unref(p);
}
}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 1d3f76f..1f4f78b 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -369,6 +369,9 @@ struct BlockDriverState {
BlockJob *job;
QDict *options;
+
+ /* The error object in use for blocking operations on backing_hd */
+ Error *backing_blocker;
};
int get_tmp_filename(char *filename, int size);
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 07/14] block: Parse "backing" option to reference existing BDS
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (5 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 06/14] block: Add backing_blocker in BlockDriverState Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 08/14] block: Support dropping active in bdrv_drop_intermediate Fam Zheng
` (6 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
Now it's safe to allow reference for backing_hd in the interface.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index edfbe59..a8d1012 100644
--- a/block.c
+++ b/block.c
@@ -1405,12 +1405,34 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
/* If there is a backing file, use it */
if ((flags & BDRV_O_NO_BACKING) == 0) {
QDict *backing_options;
+ const char *backing_name;
+ BlockDriverState *backing_hd;
+ backing_name = qdict_get_try_str(options, "backing");
qdict_extract_subqdict(options, &backing_options, "backing.");
- ret = bdrv_open_backing_file(bs, backing_options, &local_err);
- if (ret < 0) {
+
+ if (backing_name && qdict_size(backing_options)) {
+ error_setg(&local_err,
+ "Option \"backing\" and \"backing.*\" cannot be "
+ "used together");
+ ret = -EINVAL;
goto close_and_fail;
}
+ if (backing_name) {
+ backing_hd = bdrv_find(backing_name);
+ if (!backing_hd) {
+ error_set(&local_err, QERR_DEVICE_NOT_FOUND, backing_name);
+ ret = -ENOENT;
+ goto close_and_fail;
+ }
+ qdict_del(options, "backing");
+ bdrv_set_backing_hd(bs, backing_hd);
+ } else {
+ ret = bdrv_open_backing_file(bs, backing_options, &local_err);
+ if (ret < 0) {
+ goto close_and_fail;
+ }
+ }
}
done:
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 08/14] block: Support dropping active in bdrv_drop_intermediate
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (6 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 07/14] block: Parse "backing" option to reference existing BDS Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-26 19:42 ` Jeff Cody
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 09/14] stream: Use bdrv_drop_intermediate and drop close_unused_images Fam Zheng
` (5 subsequent siblings)
13 siblings, 1 reply; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
Dropping intermediate could be useful both for commit and stream, and
BDS refcnt plus bdrv_swap could do most of the job nicely. It also needs
to work with op blockers.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block.c | 137 +++++++++++++++++++++++----------------------------------
block/commit.c | 2 +-
2 files changed, 56 insertions(+), 83 deletions(-)
diff --git a/block.c b/block.c
index a8d1012..13cbdbf 100644
--- a/block.c
+++ b/block.c
@@ -2495,115 +2495,88 @@ BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
return overlay;
}
-typedef struct BlkIntermediateStates {
- BlockDriverState *bs;
- QSIMPLEQ_ENTRY(BlkIntermediateStates) entry;
-} BlkIntermediateStates;
-
-
/*
- * Drops images above 'base' up to and including 'top', and sets the image
- * above 'top' to have base as its backing file.
+ * Drops images above 'base' up to and including 'top', and sets new 'base' as
+ * backing_hd of top's overlay (the image orignally has 'top' as backing file).
+ * top's overlay may be NULL if 'top' is active, no such update needed.
+ * Requires that the top's overlay to 'top' is opened r/w.
+ *
+ * 1) This will convert the following chain:
+ *
+ * ... <- base <- ... <- top <- overlay <-... <- active
+ *
+ * to
+ *
+ * ... <- base <- overlay <- active
*
- * Requires that the overlay to 'top' is opened r/w, so that the backing file
- * information in 'bs' can be properly updated.
+ * 2) It is allowed for bottom==base, in which case it converts:
*
- * E.g., this will convert the following chain:
- * bottom <- base <- intermediate <- top <- active
+ * base <- ... <- top <- overlay <- ... <- active
*
* to
*
- * bottom <- base <- active
+ * base <- overlay <- active
*
- * It is allowed for bottom==base, in which case it converts:
+ * 2) It also allows active==top, in which case it converts:
*
- * base <- intermediate <- top <- active
+ * ... <- base <- ... <- top (active)
*
* to
*
- * base <- active
+ * ... <- base == active == top
+ *
+ * i.e. only base and lower remains: *top == *base when return.
+ *
+ * 3) If base==NULL, it will drop all the BDS below overlay and set its
+ * backing_hd to NULL. I.e.:
+ *
+ * base(NULL) <- ... <- overlay <- ... <- active
+ *
+ * to
*
- * Error conditions:
- * if active == top, that is considered an error
+ * overlay <- ... <- active
*
*/
int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
BlockDriverState *base)
{
- BlockDriverState *intermediate;
- BlockDriverState *base_bs = NULL;
- BlockDriverState *new_top_bs = NULL;
- BlkIntermediateStates *intermediate_state, *next;
- int ret = -EIO;
-
- QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete;
- QSIMPLEQ_INIT(&states_to_delete);
-
- if (!top->drv || !base->drv) {
- goto exit;
- }
+ BlockDriverState *drop_start, *overlay;
+ int ret = -EINVAL;
- new_top_bs = bdrv_find_overlay(active, top);
-
- if (new_top_bs == NULL) {
- /* we could not find the image above 'top', this is an error */
+ if (!top->drv || (base && !base->drv)) {
goto exit;
}
-
- /* special case of new_top_bs->backing_hd already pointing to base - nothing
- * to do, no intermediate images */
- if (new_top_bs->backing_hd == base) {
+ if (top == base) {
ret = 0;
- goto exit;
- }
-
- intermediate = top;
-
- /* now we will go down through the list, and add each BDS we find
- * into our deletion queue, until we hit the 'base'
- */
- while (intermediate) {
- intermediate_state = g_malloc0(sizeof(BlkIntermediateStates));
- intermediate_state->bs = intermediate;
- QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry);
-
- if (intermediate->backing_hd == base) {
- base_bs = intermediate->backing_hd;
- break;
+ } else if (top == active) {
+ assert(base);
+ drop_start = active->backing_hd;
+ bdrv_swap(active, base);
+ base->backing_hd = NULL;
+ bdrv_unref(drop_start);
+ ret = 0;
+ } else if (base) {
+ overlay = bdrv_find_overlay(active, top);
+ bdrv_set_backing_hd(overlay, base);
+ ret = 0;
+ } else {
+ /* If there's an overlay, its backing_hd points to top's BDS now,
+ * the top image is dropped but this BDS structure is kept and swapped
+ * with base, this way we keep the pointers valid after dropping top */
+ overlay = bdrv_find_overlay(active, top);
+ if (!overlay) {
+ goto exit;
}
- intermediate = intermediate->backing_hd;
- }
- if (base_bs == NULL) {
- /* something went wrong, we did not end at the base. safely
- * unravel everything, and exit with error */
- goto exit;
- }
-
- /* success - we can delete the intermediate states, and link top->base */
- ret = bdrv_change_backing_file(new_top_bs, base_bs->filename,
- base_bs->drv ? base_bs->drv->format_name : "");
- if (ret) {
- goto exit;
- }
- new_top_bs->backing_hd = base_bs;
-
- bdrv_refresh_limits(new_top_bs);
-
- QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
- /* so that bdrv_close() does not recursively close the chain */
- intermediate_state->bs->backing_hd = NULL;
- bdrv_unref(intermediate_state->bs);
+ ret = bdrv_change_backing_file(overlay, NULL, NULL);
+ if (ret) {
+ goto exit;
+ }
+ bdrv_set_backing_hd(overlay, NULL);
}
- ret = 0;
-
exit:
- QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
- g_free(intermediate_state);
- }
return ret;
}
-
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
size_t size)
{
diff --git a/block/commit.c b/block/commit.c
index acec4ac..ac598d6 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -73,6 +73,7 @@ static void coroutine_fn commit_run(void *opaque)
int bytes_written = 0;
int64_t base_len;
+ overlay_bs = bdrv_find_overlay(active, top);
ret = s->common.len = bdrv_getlength(top);
@@ -154,7 +155,6 @@ exit_restore_reopen:
if (s->base_flags != bdrv_get_flags(base)) {
bdrv_reopen(base, s->base_flags, NULL);
}
- overlay_bs = bdrv_find_overlay(active, top);
if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
}
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 09/14] stream: Use bdrv_drop_intermediate and drop close_unused_images
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (7 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 08/14] block: Support dropping active in bdrv_drop_intermediate Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-26 20:31 ` Jeff Cody
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 10/14] qmp: Add command 'blockdev-backup' Fam Zheng
` (4 subsequent siblings)
13 siblings, 1 reply; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This reuses the new bdrv_drop_intermediate.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block/stream.c | 30 +-----------------------------
1 file changed, 1 insertion(+), 29 deletions(-)
diff --git a/block/stream.c b/block/stream.c
index dd0b4ac..9cdcf0e 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -51,34 +51,6 @@ static int coroutine_fn stream_populate(BlockDriverState *bs,
return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
}
-static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
- const char *base_id)
-{
- BlockDriverState *intermediate;
- intermediate = top->backing_hd;
-
- /* Must assign before bdrv_delete() to prevent traversing dangling pointer
- * while we delete backing image instances.
- */
- top->backing_hd = base;
-
- while (intermediate) {
- BlockDriverState *unused;
-
- /* reached base */
- if (intermediate == base) {
- break;
- }
-
- unused = intermediate;
- intermediate = intermediate->backing_hd;
- unused->backing_hd = NULL;
- bdrv_unref(unused);
- }
-
- bdrv_refresh_limits(top);
-}
-
static void coroutine_fn stream_run(void *opaque)
{
StreamBlockJob *s = opaque;
@@ -192,7 +164,7 @@ wait:
}
}
ret = bdrv_change_backing_file(bs, base_id, base_fmt);
- close_unused_images(bs, base, base_id);
+ bdrv_drop_intermediate(bs, bs->backing_hd, base);
}
qemu_vfree(buf);
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 10/14] qmp: Add command 'blockdev-backup'
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (8 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 09/14] stream: Use bdrv_drop_intermediate and drop close_unused_images Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 11/14] block: Allow backup on referenced named BlockDriverState Fam Zheng
` (3 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
Similar to drive-backup, but this command uses a device id as target
instead of creating/opening an image file.
Also add blocker on target bs, since the target is also a named device
now.
Add check and report error for bs == target which became possible but is
an illegal case with introduction of blockdev-backup.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block/backup.c | 26 ++++++++++++++++++++++++++
blockdev.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
qapi-schema.json | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
qmp-commands.hx | 44 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 166 insertions(+)
diff --git a/block/backup.c b/block/backup.c
index 15a2e55..ea46340 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -344,6 +344,7 @@ static void coroutine_fn backup_run(void *opaque)
hbitmap_free(job->bitmap);
bdrv_iostatus_disable(target);
+ bdrv_op_unblock_all(target, job->common.blocker);
bdrv_unref(target);
block_job_completed(&job->common, ret);
@@ -362,6 +363,11 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
assert(target);
assert(cb);
+ if (bs == target) {
+ error_setg(errp, "Source and target cannot be the same");
+ return;
+ }
+
if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
!bdrv_iostatus_is_enabled(bs)) {
@@ -369,6 +375,24 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
return;
}
+ if (!bdrv_is_inserted(bs)) {
+ error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, bs->device_name);
+ return;
+ }
+
+ if (!bdrv_is_inserted(target)) {
+ error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, target->device_name);
+ return;
+ }
+
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
+ return;
+ }
+
+ if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) {
+ return;
+ }
+
len = bdrv_getlength(bs);
if (len < 0) {
error_setg_errno(errp, -len, "unable to get length for '%s'",
@@ -382,6 +406,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
return;
}
+ bdrv_op_block_all(target, job->common.blocker);
+
job->on_source_error = on_source_error;
job->on_target_error = on_target_error;
job->target = target;
diff --git a/blockdev.c b/blockdev.c
index 2fdf259..5ffae90 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1967,6 +1967,8 @@ void qmp_drive_backup(const char *device, const char *target,
return;
}
+ /* Although backup_run has this check too, we need to use bs->drv below, so
+ * do an early check redundantly. */
if (!bdrv_is_inserted(bs)) {
error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
return;
@@ -1983,6 +1985,7 @@ void qmp_drive_backup(const char *device, const char *target,
}
}
+ /* Early check to avoid creating target */
if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
return;
}
@@ -2045,6 +2048,50 @@ BlockDeviceInfoList *qmp_query_named_block_nodes(Error **errp)
return bdrv_named_nodes_list();
}
+void qmp_blockdev_backup(const char *device, const char *target,
+ enum MirrorSyncMode sync,
+ bool has_speed, int64_t speed,
+ bool has_on_source_error,
+ BlockdevOnError on_source_error,
+ bool has_on_target_error,
+ BlockdevOnError on_target_error,
+ Error **errp)
+{
+ BlockDriverState *bs;
+ BlockDriverState *target_bs;
+ Error *local_err = NULL;
+
+ if (!has_speed) {
+ speed = 0;
+ }
+ if (!has_on_source_error) {
+ on_source_error = BLOCKDEV_ON_ERROR_REPORT;
+ }
+ if (!has_on_target_error) {
+ on_target_error = BLOCKDEV_ON_ERROR_REPORT;
+ }
+
+ bs = bdrv_find(device);
+ if (!bs) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+ return;
+ }
+
+ target_bs = bdrv_find(target);
+ if (!target_bs) {
+ error_set(errp, QERR_DEVICE_NOT_FOUND, target);
+ return;
+ }
+
+ bdrv_ref(target_bs);
+ backup_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
+ block_job_cb, bs, &local_err);
+ if (local_err != NULL) {
+ bdrv_unref(target_bs);
+ error_propagate(errp, local_err);
+ }
+}
+
#define DEFAULT_MIRROR_BUF_SIZE (10 << 20)
void qmp_drive_mirror(const char *device, const char *target,
diff --git a/qapi-schema.json b/qapi-schema.json
index fcb22800..0721c4a 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1920,6 +1920,40 @@
'*on-target-error': 'BlockdevOnError' } }
##
+# @BlockdevBackup
+#
+# @device: the name of the device which should be copied.
+#
+# @target: the name of the backup target device.
+#
+# @sync: what parts of the disk image should be copied to the destination
+# (all the disk, only the sectors allocated in the topmost image, or
+# only new I/O).
+#
+# @speed: #optional the maximum speed, in bytes per second.
+#
+# @on-source-error: #optional the action to take on an error on the source,
+# default 'report'. 'stop' and 'enospc' can only be used
+# if the block device supports io-status (see BlockInfo).
+#
+# @on-target-error: #optional the action to take on an error on the target,
+# default 'report' (no limitations, since this applies to
+# a different block device than @device).
+#
+# Note that @on-source-error and @on-target-error only affect background I/O.
+# If an error occurs during a guest write request, the device's rerror/werror
+# actions will be used.
+#
+# Since: 2.0
+##
+{ 'type': 'BlockdevBackup',
+ 'data': { 'device': 'str', 'target': 'str',
+ 'sync': 'MirrorSyncMode',
+ '*speed': 'int',
+ '*on-source-error': 'BlockdevOnError',
+ '*on-target-error': 'BlockdevOnError' } }
+
+##
# @Abort
#
# This action can be used to test transaction failure.
@@ -2128,6 +2162,21 @@
{ 'command': 'query-named-block-nodes', 'returns': [ 'BlockDeviceInfo' ] }
##
+# @blockdev-backup
+#
+# Block device version for drive-backup command. Use existing device as target
+# of backup.
+#
+# For the arguments, see the documentation of BlockdevBackup.
+#
+# Returns: Nothing on success.
+# If @device or @target is not a valid block device, DeviceNotFound.
+#
+# Since 2.0
+##
+{ 'command': 'blockdev-backup', 'data': 'BlockdevBackup' }
+
+##
# @drive-mirror
#
# Start mirroring a block device's writes to a new destination.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 8a0e832..586032a 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1054,6 +1054,50 @@ Example:
"sync": "full",
"target": "backup.img" } }
<- { "return": {} }
+
+EQMP
+
+ {
+ .name = "blockdev-backup",
+ .args_type = "sync:s,device:B,target:B,speed:i?,"
+ "on-source-error:s?,on-target-error:s?",
+ .mhandler.cmd_new = qmp_marshal_input_blockdev_backup,
+ },
+
+SQMP
+blockdev-backup
+------------
+
+The device version of drive-backup: this command takes a existing named device
+as backup target.
+
+Arguments:
+
+- "device": the name of the device which should be copied.
+ (json-string)
+- "target": the target of the new image. If the file exists, or if it is a
+ device, the existing file/device will be used as the new
+ destination. If it does not exist, a new file will be created.
+ (json-string)
+- "sync": what parts of the disk image should be copied to the destination;
+ possibilities include "full" for all the disk, "top" for only the
+ sectors allocated in the topmost image, or "none" to only replicate
+ new I/O (MirrorSyncMode).
+- "speed": the maximum speed, in bytes per second (json-int, optional)
+- "on-source-error": the action to take on an error on the source, default
+ 'report'. 'stop' and 'enospc' can only be used
+ if the block device supports io-status.
+ (BlockdevOnError, optional)
+- "on-target-error": the action to take on an error on the target, default
+ 'report' (no limitations, since this applies to
+ a different block device than device).
+ (BlockdevOnError, optional)
+
+Example:
+-> { "execute": "blockdev-backup", "arguments": { "device": "src-id",
+ "target": "tgt-id" } }
+<- { "return": {} }
+
EQMP
{
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 11/14] block: Allow backup on referenced named BlockDriverState
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (9 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 10/14] qmp: Add command 'blockdev-backup' Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 12/14] block: Add blockdev-backup to transaction Fam Zheng
` (2 subsequent siblings)
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
Drive backup is a read only operation on source bs. We want to allow
this specific case to enable image-fleecing. Note that when
image-fleecing job starts, the job still add its blocker to source bs,
and any other operation on it will be blocked by that.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
block.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block.c b/block.c
index 13cbdbf..29e93d3 100644
--- a/block.c
+++ b/block.c
@@ -1077,6 +1077,8 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
/* Otherwise we won't be able to commit due to check in bdrv_commit */
bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT,
bs->backing_blocker);
+ bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
+ bs->backing_blocker);
out:
bdrv_refresh_limits(bs);
}
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 12/14] block: Add blockdev-backup to transaction
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (10 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 11/14] block: Allow backup on referenced named BlockDriverState Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 13/14] qemu-iotests: Test blockdev-backup in 055 Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 14/14] qemu-iotests: Image fleecing test case 083 Fam Zheng
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
Signed-off-by: Fam Zheng <famz@redhat.com>
---
blockdev.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
qapi-schema.json | 1 +
2 files changed, 49 insertions(+)
diff --git a/blockdev.c b/blockdev.c
index 5ffae90..5db5bbb 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1409,6 +1409,49 @@ static void drive_backup_abort(BlkTransactionState *common)
}
}
+typedef struct BlockdevBackupState {
+ BlkTransactionState common;
+ BlockDriverState *bs;
+ BlockJob *job;
+} BlockdevBackupState;
+
+static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
+{
+ BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
+ BlockdevBackup *backup;
+ Error *local_err = NULL;
+
+ assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
+ backup = common->action->blockdev_backup;
+
+ qmp_blockdev_backup(backup->device, backup->target,
+ backup->sync,
+ backup->has_speed, backup->speed,
+ backup->has_on_source_error, backup->on_source_error,
+ backup->has_on_target_error, backup->on_target_error,
+ &local_err);
+ if (error_is_set(&local_err)) {
+ error_propagate(errp, local_err);
+ state->bs = NULL;
+ state->job = NULL;
+ return;
+ }
+
+ state->bs = bdrv_find(backup->device);
+ state->job = state->bs->job;
+}
+
+static void blockdev_backup_abort(BlkTransactionState *common)
+{
+ BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
+ BlockDriverState *bs = state->bs;
+
+ /* Only cancel if it's the job we started */
+ if (bs && bs->job && bs->job == state->job) {
+ block_job_cancel_sync(bs->job);
+ }
+}
+
static void abort_prepare(BlkTransactionState *common, Error **errp)
{
error_setg(errp, "Transaction aborted using Abort action");
@@ -1431,6 +1474,11 @@ static const BdrvActionOps actions[] = {
.prepare = drive_backup_prepare,
.abort = drive_backup_abort,
},
+ [TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = {
+ .instance_size = sizeof(BlockdevBackupState),
+ .prepare = blockdev_backup_prepare,
+ .abort = blockdev_backup_abort,
+ },
[TRANSACTION_ACTION_KIND_ABORT] = {
.instance_size = sizeof(BlkTransactionState),
.prepare = abort_prepare,
diff --git a/qapi-schema.json b/qapi-schema.json
index 0721c4a..068e2e8 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1973,6 +1973,7 @@
'data': {
'blockdev-snapshot-sync': 'BlockdevSnapshot',
'drive-backup': 'DriveBackup',
+ 'blockdev-backup': 'BlockdevBackup',
'abort': 'Abort',
'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal'
} }
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 13/14] qemu-iotests: Test blockdev-backup in 055
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (11 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 12/14] block: Add blockdev-backup to transaction Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 14/14] qemu-iotests: Image fleecing test case 083 Fam Zheng
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This applies cases on drive-backup on blockdev-backup, except cases with
target format and mode.
Also add a case to check source == target.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
tests/qemu-iotests/055 | 275 ++++++++++++++++++++++++++++++++++++++-------
tests/qemu-iotests/055.out | 4 +-
2 files changed, 235 insertions(+), 44 deletions(-)
diff --git a/tests/qemu-iotests/055 b/tests/qemu-iotests/055
index 451b67d..1fab088 100755
--- a/tests/qemu-iotests/055
+++ b/tests/qemu-iotests/055
@@ -1,6 +1,6 @@
#!/usr/bin/env python
#
-# Tests for drive-backup
+# Tests for drive-backup and blockdev-backup
#
# Copyright (C) 2013 Red Hat, Inc.
#
@@ -27,6 +27,7 @@ from iotests import qemu_img, qemu_io
test_img = os.path.join(iotests.test_dir, 'test.img')
target_img = os.path.join(iotests.test_dir, 'target.img')
+blockdev_target_img = os.path.join(iotests.test_dir, 'blockdev-target.img')
class TestSingleDrive(iotests.QMPTestCase):
image_len = 64 * 1024 * 1024 # MB
@@ -38,34 +39,48 @@ class TestSingleDrive(iotests.QMPTestCase):
qemu_io('-c', 'write -P0xd5 1M 32k', test_img)
qemu_io('-c', 'write -P0xdc 32M 124k', test_img)
qemu_io('-c', 'write -P0xdc 67043328 64k', test_img)
+ qemu_img('create', '-f', iotests.imgfmt, blockdev_target_img, str(TestSingleDrive.image_len))
- self.vm = iotests.VM().add_drive(test_img)
+ self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img)
self.vm.launch()
def tearDown(self):
self.vm.shutdown()
os.remove(test_img)
+ os.remove(blockdev_target_img)
try:
os.remove(target_img)
except OSError:
pass
- def test_cancel(self):
+ def do_test_cancel(self, test_drive_backup):
self.assert_no_active_block_jobs()
- result = self.vm.qmp('drive-backup', device='drive0',
- target=target_img, sync='full')
+ if test_drive_backup:
+ result = self.vm.qmp('drive-backup', device='drive0',
+ target=target_img, sync='full')
+ else:
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive1', sync='full')
self.assert_qmp(result, 'return', {})
event = self.cancel_and_wait()
self.assert_qmp(event, 'data/type', 'backup')
- def test_pause(self):
+ def test_cancel(self):
+ self.do_test_cancel(True)
+ self.do_test_cancel(False)
+
+ def do_test_pause(self, test_drive_backup):
self.assert_no_active_block_jobs()
self.vm.pause_drive('drive0')
- result = self.vm.qmp('drive-backup', device='drive0',
- target=target_img, sync='full')
+ if test_drive_backup:
+ result = self.vm.qmp('drive-backup', device='drive0',
+ target=target_img, sync='full')
+ else:
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive1', sync='full')
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('block-job-pause', device='drive0')
@@ -86,14 +101,28 @@ class TestSingleDrive(iotests.QMPTestCase):
self.wait_until_completed()
self.vm.shutdown()
- self.assertTrue(iotests.compare_images(test_img, target_img),
- 'target image does not match source after backup')
+ if test_drive_backup:
+ self.assertTrue(iotests.compare_images(test_img, target_img),
+ 'target image does not match source after backup')
+ else:
+ self.assertTrue(iotests.compare_images(test_img, blockdev_target_img),
+ 'target image does not match source after backup')
+
+ def test_pause_drive_backup(self):
+ self.do_test_pause(True)
+
+ def test_pause_blockdev_backup(self):
+ self.do_test_pause(False)
def test_medium_not_found(self):
result = self.vm.qmp('drive-backup', device='ide1-cd0',
target=target_img, sync='full')
self.assert_qmp(result, 'error/class', 'GenericError')
+ result = self.vm.qmp('blockdev-backup', device='ide1-cd0',
+ target='drive1', sync='full')
+ self.assert_qmp(result, 'error/class', 'GenericError')
+
def test_image_not_found(self):
result = self.vm.qmp('drive-backup', device='drive0',
target=target_img, sync='full', mode='existing')
@@ -110,26 +139,56 @@ class TestSingleDrive(iotests.QMPTestCase):
target=target_img, sync='full')
self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+ result = self.vm.qmp('blockdev-backup', device='nonexistent',
+ target='drive0', sync='full')
+ self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='nonexistent', sync='full')
+ self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+ result = self.vm.qmp('blockdev-backup', device='nonexistent',
+ target='nonexistent', sync='full')
+ self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+ def test_target_is_source(self):
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive0', sync='full')
+ self.assert_qmp(result, 'error/class', 'GenericError')
+
class TestSetSpeed(iotests.QMPTestCase):
image_len = 80 * 1024 * 1024 # MB
def setUp(self):
qemu_img('create', '-f', iotests.imgfmt, test_img, str(TestSetSpeed.image_len))
qemu_io('-c', 'write -P1 0 512', test_img)
- self.vm = iotests.VM().add_drive(test_img)
+ qemu_img('create', '-f', iotests.imgfmt, blockdev_target_img, str(TestSingleDrive.image_len))
+
+ self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img)
self.vm.launch()
def tearDown(self):
self.vm.shutdown()
os.remove(test_img)
- os.remove(target_img)
+ try:
+ os.remove(blockdev_target_img)
+ except OSError:
+ pass
+ try:
+ os.remove(target_img)
+ except OSError:
+ pass
- def test_set_speed(self):
+ def do_test_set_speed(self, test_drive_backup):
self.assert_no_active_block_jobs()
self.vm.pause_drive('drive0')
- result = self.vm.qmp('drive-backup', device='drive0',
- target=target_img, sync='full')
+ if test_drive_backup:
+ result = self.vm.qmp('drive-backup', device='drive0',
+ target=target_img, sync='full')
+ else:
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive1', sync='full')
self.assert_qmp(result, 'return', {})
# Default speed is 0
@@ -148,10 +207,14 @@ class TestSetSpeed(iotests.QMPTestCase):
event = self.cancel_and_wait(resume=True)
self.assert_qmp(event, 'data/type', 'backup')
- # Check setting speed in drive-backup works
+ # Check setting speed option works
self.vm.pause_drive('drive0')
- result = self.vm.qmp('drive-backup', device='drive0',
- target=target_img, sync='full', speed=4*1024*1024)
+ if test_drive_backup:
+ result = self.vm.qmp('drive-backup', device='drive0',
+ target=target_img, sync='full', speed=4*1024*1024)
+ else:
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive1', sync='full', speed=4*1024*1024)
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('query-block-jobs')
@@ -161,18 +224,32 @@ class TestSetSpeed(iotests.QMPTestCase):
event = self.cancel_and_wait(resume=True)
self.assert_qmp(event, 'data/type', 'backup')
- def test_set_speed_invalid(self):
+ def test_set_speed_drive_backup(self):
+ self.do_test_set_speed(True)
+
+ def test_set_speed_blockdev_backup(self):
+ self.do_test_set_speed(False)
+
+ def do_test_set_speed_invalid(self, test_drive_backup):
self.assert_no_active_block_jobs()
- result = self.vm.qmp('drive-backup', device='drive0',
- target=target_img, sync='full', speed=-1)
+ if test_drive_backup:
+ result = self.vm.qmp('drive-backup', device='drive0',
+ target=target_img, sync='full', speed=-1)
+ else:
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive1', sync='full', speed=-1)
self.assert_qmp(result, 'error/class', 'GenericError')
self.assert_no_active_block_jobs()
self.vm.pause_drive('drive0')
- result = self.vm.qmp('drive-backup', device='drive0',
- target=target_img, sync='full')
+ if test_drive_backup:
+ result = self.vm.qmp('drive-backup', device='drive0',
+ target=target_img, sync='full')
+ else:
+ result = self.vm.qmp('blockdev-backup', device='drive0',
+ target='drive1', sync='full')
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('block-job-set-speed', device='drive0', speed=-1)
@@ -181,6 +258,12 @@ class TestSetSpeed(iotests.QMPTestCase):
event = self.cancel_and_wait(resume=True)
self.assert_qmp(event, 'data/type', 'backup')
+ def test_set_speed_invalid_drive_backup(self):
+ self.do_test_set_speed_invalid(True)
+
+ def test_set_speed_invalid_blockdev_backup(self):
+ self.do_test_set_speed_invalid(False)
+
class TestSingleTransaction(iotests.QMPTestCase):
image_len = 64 * 1024 * 1024 # MB
@@ -190,44 +273,71 @@ class TestSingleTransaction(iotests.QMPTestCase):
qemu_io('-c', 'write -P0xd5 1M 32k', test_img)
qemu_io('-c', 'write -P0xdc 32M 124k', test_img)
qemu_io('-c', 'write -P0xdc 67043328 64k', test_img)
+ qemu_img('create', '-f', iotests.imgfmt, blockdev_target_img, str(TestSingleDrive.image_len))
- self.vm = iotests.VM().add_drive(test_img)
+ self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img)
self.vm.launch()
def tearDown(self):
self.vm.shutdown()
os.remove(test_img)
+ os.remove(blockdev_target_img)
try:
os.remove(target_img)
except OSError:
pass
- def test_cancel(self):
+ def do_test_cancel(self, test_drive_backup):
self.assert_no_active_block_jobs()
- result = self.vm.qmp('transaction', actions=[{
- 'type': 'drive-backup',
- 'data': { 'device': 'drive0',
- 'target': target_img,
- 'sync': 'full' },
- }
- ])
+ if test_drive_backup:
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'drive-backup',
+ 'data': { 'device': 'drive0',
+ 'target': target_img,
+ 'sync': 'full' },
+ }
+ ])
+ else:
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'drive0',
+ 'target': 'drive1',
+ 'sync': 'full' },
+ }
+ ])
+
self.assert_qmp(result, 'return', {})
event = self.cancel_and_wait()
self.assert_qmp(event, 'data/type', 'backup')
- def test_pause(self):
+ def test_cancel_drive_backup(self):
+ self.do_test_cancel(True)
+
+ def test_cancel_blockdev_backup(self):
+ self.do_test_cancel(False)
+
+ def do_test_pause(self, test_drive_backup):
self.assert_no_active_block_jobs()
self.vm.pause_drive('drive0')
- result = self.vm.qmp('transaction', actions=[{
- 'type': 'drive-backup',
- 'data': { 'device': 'drive0',
- 'target': target_img,
- 'sync': 'full' },
- }
- ])
+ if test_drive_backup:
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'drive-backup',
+ 'data': { 'device': 'drive0',
+ 'target': target_img,
+ 'sync': 'full' },
+ }
+ ])
+ else:
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'drive0',
+ 'target': 'drive1',
+ 'sync': 'full' },
+ }
+ ])
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('block-job-pause', device='drive0')
@@ -248,8 +358,18 @@ class TestSingleTransaction(iotests.QMPTestCase):
self.wait_until_completed()
self.vm.shutdown()
- self.assertTrue(iotests.compare_images(test_img, target_img),
- 'target image does not match source after backup')
+ if test_drive_backup:
+ self.assertTrue(iotests.compare_images(test_img, target_img),
+ 'target image does not match source after backup')
+ else:
+ self.assertTrue(iotests.compare_images(test_img, blockdev_target_img),
+ 'target image does not match source after backup')
+
+ def test_pause_drive_backup(self):
+ self.do_test_pause(True)
+
+ def test_pause_blockdev_backup(self):
+ self.do_test_pause(False)
def test_medium_not_found(self):
result = self.vm.qmp('transaction', actions=[{
@@ -260,6 +380,14 @@ class TestSingleTransaction(iotests.QMPTestCase):
}
])
self.assert_qmp(result, 'error/class', 'GenericError')
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'ide1-cd0',
+ 'target': 'drive1',
+ 'sync': 'full' },
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'GenericError')
def test_image_not_found(self):
result = self.vm.qmp('transaction', actions=[{
@@ -283,6 +411,43 @@ class TestSingleTransaction(iotests.QMPTestCase):
])
self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'nonexistent',
+ 'target': 'drive1',
+ 'sync': 'full' },
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'drive0',
+ 'target': 'nonexistent',
+ 'sync': 'full' },
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'nonexistent',
+ 'target': 'nonexistent',
+ 'sync': 'full' },
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+ def test_target_is_source(self):
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'drive0',
+ 'target': 'drive0',
+ 'sync': 'full' },
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'GenericError')
+
def test_abort(self):
result = self.vm.qmp('transaction', actions=[{
'type': 'drive-backup',
@@ -298,5 +463,31 @@ class TestSingleTransaction(iotests.QMPTestCase):
self.assert_qmp(result, 'error/class', 'GenericError')
self.assert_no_active_block_jobs()
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'nonexistent',
+ 'target': 'drive1',
+ 'sync': 'full' },
+ }, {
+ 'type': 'Abort',
+ 'data': {},
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'GenericError')
+ self.assert_no_active_block_jobs()
+
+ result = self.vm.qmp('transaction', actions=[{
+ 'type': 'blockdev-backup',
+ 'data': { 'device': 'drive0',
+ 'target': 'nonexistent',
+ 'sync': 'full' },
+ }, {
+ 'type': 'Abort',
+ 'data': {},
+ }
+ ])
+ self.assert_qmp(result, 'error/class', 'GenericError')
+ self.assert_no_active_block_jobs()
+
if __name__ == '__main__':
iotests.main(supported_fmts=['raw', 'qcow2'])
diff --git a/tests/qemu-iotests/055.out b/tests/qemu-iotests/055.out
index 6323079..c6a10f8 100644
--- a/tests/qemu-iotests/055.out
+++ b/tests/qemu-iotests/055.out
@@ -1,5 +1,5 @@
-..............
+.....................
----------------------------------------------------------------------
-Ran 14 tests
+Ran 21 tests
OK
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Qemu-devel] [PATCH v15 14/14] qemu-iotests: Image fleecing test case 083
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
` (12 preceding siblings ...)
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 13/14] qemu-iotests: Test blockdev-backup in 055 Fam Zheng
@ 2014-02-23 1:54 ` Fam Zheng
13 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-02-23 1:54 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, benoit.canet, rjones, armbru, imain, stefanha, pbonzini,
ptoscano
This tests the workflow of creating a lightweight point-in-time snapshot
with blockdev-backup command and export it with built-in NBD server.
It's tested that after the snapshot it created, writing to the original
device doesn't change data that can be read from target with NBD.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
tests/qemu-iotests/083 | 99 ++++++++++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/083.out | 5 +++
tests/qemu-iotests/group | 1 +
3 files changed, 105 insertions(+)
create mode 100755 tests/qemu-iotests/083
create mode 100644 tests/qemu-iotests/083.out
diff --git a/tests/qemu-iotests/083 b/tests/qemu-iotests/083
new file mode 100755
index 0000000..8be32d7
--- /dev/null
+++ b/tests/qemu-iotests/083
@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+#
+# Tests for image fleecing (point in time snapshot export to NBD)
+#
+# Copyright (C) 2014 Red Hat, Inc.
+#
+# Based on 055.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+import time
+import os
+import iotests
+from iotests import qemu_img, qemu_io
+
+test_img = os.path.join(iotests.test_dir, 'test.img')
+target_img = os.path.join(iotests.test_dir, 'target.img')
+nbd_sock = os.path.join(iotests.test_dir, 'nbd.sock')
+
+class TestImageFleecing(iotests.QMPTestCase):
+ image_len = 64 * 1024 * 1024 # MB
+
+ def setUp(self):
+ # Write data to the image so we can compare later
+ qemu_img('create', '-f', iotests.imgfmt, test_img, str(TestImageFleecing.image_len))
+ self.patterns = [
+ ("0x5d", "0", "64k"),
+ ("0xd5", "1M", "64k"),
+ ("0xdc", "32M", "64k"),
+ ("0xdc", "67043328", "64k")]
+
+ for p in self.patterns:
+ qemu_io('-c', 'write -P%s %s %s' % p, test_img)
+
+ qemu_img('create', '-f', iotests.imgfmt, target_img, str(TestImageFleecing.image_len))
+
+ self.vm = iotests.VM().add_drive(test_img)
+ self.vm.launch()
+
+ self.overwrite_patterns = [
+ ("0xa0", "0", "64k"),
+ ("0x0a", "1M", "64k"),
+ ("0x55", "32M", "64k"),
+ ("0x56", "67043328", "64k")]
+
+ self.nbd_uri = "nbd+unix:///drive1?socket=%s" % nbd_sock
+
+ def tearDown(self):
+ self.vm.shutdown()
+ os.remove(test_img)
+ os.remove(target_img)
+
+ def verify_patterns(self):
+ for p in self.patterns:
+ self.assertEqual(-1, qemu_io(self.nbd_uri, '-c', 'read -P%s %s %s' % p).find("verification failed"),
+ "Failed to verify pattern: %s %s %s" % p)
+
+ def test_image_fleecing(self):
+ result = self.vm.qmp("blockdev-add", **{"options": {
+ "driver": "qcow2",
+ "id": "drive1",
+ "file": {
+ "driver": "file",
+ "filename": target_img,
+ },
+ "backing": "drive0",
+ }})
+ self.assert_qmp(result, 'return', {})
+ result = self.vm.qmp("nbd-server-start", **{"addr": { "type": "unix", "data": { "path": nbd_sock } } })
+ self.assert_qmp(result, 'return', {})
+ result = self.vm.qmp("blockdev-backup", device="drive0", target="drive1", sync="none")
+ self.assert_qmp(result, 'return', {})
+ result = self.vm.qmp("nbd-server-add", device="drive1")
+ self.assert_qmp(result, 'return', {})
+
+ self.verify_patterns()
+
+ for p in self.overwrite_patterns:
+ self.vm.hmp_qemu_io("drive0", "write -P%s %s %s" % p)
+
+ self.verify_patterns()
+
+ self.cancel_and_wait(resume=True)
+ self.assert_no_active_block_jobs()
+
+if __name__ == '__main__':
+ iotests.main(supported_fmts=['raw', 'qcow2'])
diff --git a/tests/qemu-iotests/083.out b/tests/qemu-iotests/083.out
new file mode 100644
index 0000000..ae1213e
--- /dev/null
+++ b/tests/qemu-iotests/083.out
@@ -0,0 +1,5 @@
+.
+----------------------------------------------------------------------
+Ran 1 tests
+
+OK
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index db127d9..f88757e 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -85,3 +85,4 @@
079 rw auto
081 rw auto
082 rw auto quick
+083 rw auto quick
--
1.8.5.4
^ permalink raw reply related [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 08/14] block: Support dropping active in bdrv_drop_intermediate
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 08/14] block: Support dropping active in bdrv_drop_intermediate Fam Zheng
@ 2014-02-26 19:42 ` Jeff Cody
0 siblings, 0 replies; 22+ messages in thread
From: Jeff Cody @ 2014-02-26 19:42 UTC (permalink / raw)
To: Fam Zheng
Cc: kwolf, benoit.canet, rjones, qemu-devel, armbru, imain, stefanha,
pbonzini, ptoscano
On Sun, Feb 23, 2014 at 09:54:49AM +0800, Fam Zheng wrote:
> Dropping intermediate could be useful both for commit and stream, and
> BDS refcnt plus bdrv_swap could do most of the job nicely. It also needs
> to work with op blockers.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
> block.c | 137 +++++++++++++++++++++++----------------------------------
> block/commit.c | 2 +-
> 2 files changed, 56 insertions(+), 83 deletions(-)
>
> diff --git a/block.c b/block.c
> index a8d1012..13cbdbf 100644
> --- a/block.c
> +++ b/block.c
> @@ -2495,115 +2495,88 @@ BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
> return overlay;
> }
>
> -typedef struct BlkIntermediateStates {
> - BlockDriverState *bs;
> - QSIMPLEQ_ENTRY(BlkIntermediateStates) entry;
> -} BlkIntermediateStates;
> -
> -
> /*
> - * Drops images above 'base' up to and including 'top', and sets the image
> - * above 'top' to have base as its backing file.
> + * Drops images above 'base' up to and including 'top', and sets new 'base' as
> + * backing_hd of top's overlay (the image orignally has 'top' as backing file).
> + * top's overlay may be NULL if 'top' is active, no such update needed.
> + * Requires that the top's overlay to 'top' is opened r/w.
> + *
> + * 1) This will convert the following chain:
> + *
> + * ... <- base <- ... <- top <- overlay <-... <- active
> + *
> + * to
> + *
> + * ... <- base <- overlay <- active
> *
> - * Requires that the overlay to 'top' is opened r/w, so that the backing file
> - * information in 'bs' can be properly updated.
> + * 2) It is allowed for bottom==base, in which case it converts:
> *
> - * E.g., this will convert the following chain:
> - * bottom <- base <- intermediate <- top <- active
> + * base <- ... <- top <- overlay <- ... <- active
> *
> * to
> *
> - * bottom <- base <- active
> + * base <- overlay <- active
> *
> - * It is allowed for bottom==base, in which case it converts:
> + * 2) It also allows active==top, in which case it converts:
> *
> - * base <- intermediate <- top <- active
> + * ... <- base <- ... <- top (active)
> *
> * to
> *
> - * base <- active
> + * ... <- base == active == top
> + *
> + * i.e. only base and lower remains: *top == *base when return.
> + *
> + * 3) If base==NULL, it will drop all the BDS below overlay and set its
> + * backing_hd to NULL. I.e.:
> + *
> + * base(NULL) <- ... <- overlay <- ... <- active
> + *
> + * to
> *
> - * Error conditions:
> - * if active == top, that is considered an error
> + * overlay <- ... <- active
> *
> */
> int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
> BlockDriverState *base)
> {
> - BlockDriverState *intermediate;
> - BlockDriverState *base_bs = NULL;
> - BlockDriverState *new_top_bs = NULL;
> - BlkIntermediateStates *intermediate_state, *next;
> - int ret = -EIO;
> -
> - QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete;
> - QSIMPLEQ_INIT(&states_to_delete);
> -
> - if (!top->drv || !base->drv) {
> - goto exit;
> - }
> + BlockDriverState *drop_start, *overlay;
> + int ret = -EINVAL;
>
> - new_top_bs = bdrv_find_overlay(active, top);
> -
> - if (new_top_bs == NULL) {
> - /* we could not find the image above 'top', this is an error */
> + if (!top->drv || (base && !base->drv)) {
> goto exit;
> }
> -
> - /* special case of new_top_bs->backing_hd already pointing to base - nothing
> - * to do, no intermediate images */
> - if (new_top_bs->backing_hd == base) {
> + if (top == base) {
> ret = 0;
> - goto exit;
> - }
> -
> - intermediate = top;
> -
> - /* now we will go down through the list, and add each BDS we find
> - * into our deletion queue, until we hit the 'base'
> - */
> - while (intermediate) {
> - intermediate_state = g_malloc0(sizeof(BlkIntermediateStates));
> - intermediate_state->bs = intermediate;
> - QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry);
> -
> - if (intermediate->backing_hd == base) {
> - base_bs = intermediate->backing_hd;
> - break;
> + } else if (top == active) {
> + assert(base);
Hmm. I'm trying to think of any edge cases here, if something could
fail. We know base != NULL, we know that top = active, and that
top != base. That is good. But we don't have any verification at
this point that base is in the same chain as top / active.
Is this worth verifying? I think it probably is... a simple way
would be to just add here something like this:
drop_start = active;
while (drop_start && drop_start != base) {
drop_start = drop_start->backing_hd;
}
if (drop_start == NULL) {
goto exit;
}
(or use a new BDS pointer for better clarity, rather than reusing
drop_start, if desired)
> + drop_start = active->backing_hd;
> + bdrv_swap(active, base);
> + base->backing_hd = NULL;
> + bdrv_unref(drop_start);
> + ret = 0;
> + } else if (base) {
> + overlay = bdrv_find_overlay(active, top);
Error check needed - overlay could be NULL.
> + bdrv_set_backing_hd(overlay, base);
> + ret = 0;
This breaks block-commit here, because the backing file is not changed
in the overlay image file.
> + } else {
> + /* If there's an overlay, its backing_hd points to top's BDS now,
> + * the top image is dropped but this BDS structure is kept and swapped
> + * with base, this way we keep the pointers valid after dropping top */
> + overlay = bdrv_find_overlay(active, top);
> + if (!overlay) {
> + goto exit;
> }
> - intermediate = intermediate->backing_hd;
> - }
> - if (base_bs == NULL) {
> - /* something went wrong, we did not end at the base. safely
> - * unravel everything, and exit with error */
> - goto exit;
> - }
> -
> - /* success - we can delete the intermediate states, and link top->base */
> - ret = bdrv_change_backing_file(new_top_bs, base_bs->filename,
> - base_bs->drv ? base_bs->drv->format_name : "");
> - if (ret) {
> - goto exit;
> - }
> - new_top_bs->backing_hd = base_bs;
> -
> - bdrv_refresh_limits(new_top_bs);
> -
> - QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
> - /* so that bdrv_close() does not recursively close the chain */
> - intermediate_state->bs->backing_hd = NULL;
> - bdrv_unref(intermediate_state->bs);
> + ret = bdrv_change_backing_file(overlay, NULL, NULL);
> + if (ret) {
> + goto exit;
> + }
As mentioned above, the backing file needs to be changed in each case
(except the top == base case), not just when base == NULL.
> + bdrv_set_backing_hd(overlay, NULL);
> }
> - ret = 0;
> -
> exit:
> - QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
> - g_free(intermediate_state);
> - }
> return ret;
> }
>
> -
> static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
> size_t size)
> {
> diff --git a/block/commit.c b/block/commit.c
> index acec4ac..ac598d6 100644
> --- a/block/commit.c
> +++ b/block/commit.c
> @@ -73,6 +73,7 @@ static void coroutine_fn commit_run(void *opaque)
> int bytes_written = 0;
> int64_t base_len;
>
> + overlay_bs = bdrv_find_overlay(active, top);
> ret = s->common.len = bdrv_getlength(top);
>
>
> @@ -154,7 +155,6 @@ exit_restore_reopen:
> if (s->base_flags != bdrv_get_flags(base)) {
> bdrv_reopen(base, s->base_flags, NULL);
> }
> - overlay_bs = bdrv_find_overlay(active, top);
> if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
> bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
> }
> --
> 1.8.5.4
>
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 09/14] stream: Use bdrv_drop_intermediate and drop close_unused_images
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 09/14] stream: Use bdrv_drop_intermediate and drop close_unused_images Fam Zheng
@ 2014-02-26 20:31 ` Jeff Cody
0 siblings, 0 replies; 22+ messages in thread
From: Jeff Cody @ 2014-02-26 20:31 UTC (permalink / raw)
To: Fam Zheng
Cc: kwolf, benoit.canet, rjones, qemu-devel, armbru, imain, stefanha,
pbonzini, ptoscano
On Sun, Feb 23, 2014 at 09:54:50AM +0800, Fam Zheng wrote:
> This reuses the new bdrv_drop_intermediate.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
> block/stream.c | 30 +-----------------------------
> 1 file changed, 1 insertion(+), 29 deletions(-)
>
> diff --git a/block/stream.c b/block/stream.c
> index dd0b4ac..9cdcf0e 100644
> --- a/block/stream.c
> +++ b/block/stream.c
> @@ -51,34 +51,6 @@ static int coroutine_fn stream_populate(BlockDriverState *bs,
> return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
> }
>
> -static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
> - const char *base_id)
> -{
> - BlockDriverState *intermediate;
> - intermediate = top->backing_hd;
> -
> - /* Must assign before bdrv_delete() to prevent traversing dangling pointer
> - * while we delete backing image instances.
> - */
> - top->backing_hd = base;
> -
> - while (intermediate) {
> - BlockDriverState *unused;
> -
> - /* reached base */
> - if (intermediate == base) {
> - break;
> - }
> -
> - unused = intermediate;
> - intermediate = intermediate->backing_hd;
> - unused->backing_hd = NULL;
> - bdrv_unref(unused);
> - }
> -
> - bdrv_refresh_limits(top);
> -}
> -
> static void coroutine_fn stream_run(void *opaque)
> {
> StreamBlockJob *s = opaque;
> @@ -192,7 +164,7 @@ wait:
> }
> }
> ret = bdrv_change_backing_file(bs, base_id, base_fmt);
This call to bdrv_change_backing_file() should be removed now, as well
as the supporting code above it (not seen in the diff context):
const char *base_id = NULL, *base_fmt = NULL;
if (base) {
base_id = s->backing_file_id;
if (base->drv) {
base_fmt = base->drv->format_name;
}
}
This is (should be) taken care of in bdrv_drop_intermediate().
> - close_unused_images(bs, base, base_id);
> + bdrv_drop_intermediate(bs, bs->backing_hd, base);
> }
>
> qemu_vfree(buf);
> --
> 1.8.5.4
>
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd()
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd() Fam Zheng
@ 2014-02-26 21:45 ` Jeff Cody
2014-02-26 22:35 ` Jeff Cody
1 sibling, 0 replies; 22+ messages in thread
From: Jeff Cody @ 2014-02-26 21:45 UTC (permalink / raw)
To: Fam Zheng
Cc: kwolf, benoit.canet, rjones, qemu-devel, armbru, imain, stefanha,
pbonzini, ptoscano
On Sun, Feb 23, 2014 at 09:54:46AM +0800, Fam Zheng wrote:
> This is the common but non-trivial steps to assign or change the
> backing_hd of BDS.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
> block.c | 46 ++++++++++++++++++++++++++++++++++++++--------
> include/block/block.h | 1 +
> 2 files changed, 39 insertions(+), 8 deletions(-)
>
> diff --git a/block.c b/block.c
> index 684b9d6..9caade9 100644
> --- a/block.c
> +++ b/block.c
> @@ -1041,6 +1041,32 @@ fail:
> return ret;
> }
>
> +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
> +{
> + if (backing_hd) {
> + /* Grab the reference before unref original backing_hd, so we are safe
> + * when rebasing in the backing chain.
> + */
> + bdrv_ref(backing_hd);
> + }
> +
> + if (bs->backing_hd) {
> + bdrv_unref(bs->backing_hd);
> + }
> +
> + bs->backing_hd = backing_hd;
> + if (!backing_hd) {
> + bs->backing_file[0] = '\0';
> + bs->backing_format[0] = '\0';
> + goto out;
> + }
> + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
> + pstrcpy(bs->backing_format, sizeof(bs->backing_format),
> + backing_hd->drv ? backing_hd->drv->format_name : "");
> +out:
> + bdrv_refresh_limits(bs);
> +}
> +
> /*
> * Opens the backing file for a BlockDriverState if not yet open
> *
> @@ -1054,6 +1080,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
> char backing_filename[PATH_MAX];
> int back_flags, ret;
> BlockDriver *back_drv = NULL;
> + BlockDriverState *backing_hd;
> Error *local_err = NULL;
>
> if (bs->backing_hd != NULL) {
> @@ -1077,6 +1104,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
> sizeof(backing_filename));
> }
>
> + backing_hd = bdrv_new("");
> +
> if (bs->backing_format[0] != '\0') {
> back_drv = bdrv_find_format(bs->backing_format);
> }
> @@ -1085,23 +1114,24 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
> back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT |
> BDRV_O_COPY_ON_READ);
>
> - assert(bs->backing_hd == NULL);
> - ret = bdrv_open(&bs->backing_hd,
> + ret = bdrv_open(&backing_hd,
> *backing_filename ? backing_filename : NULL, NULL, options,
> back_flags, back_drv, &local_err);
> if (ret < 0) {
> bs->backing_hd = NULL;
Assigning bs->backing_hd = NULL is no longer needed now, so this
should be removed.
> + bdrv_unref(backing_hd);
> + backing_hd = NULL;
> bs->open_flags |= BDRV_O_NO_BACKING;
> error_setg(errp, "Could not open backing file: %s",
> error_get_pretty(local_err));
> error_free(local_err);
> return ret;
> }
> -
> - if (bs->backing_hd->file) {
> - pstrcpy(bs->backing_file, sizeof(bs->backing_file),
> - bs->backing_hd->file->filename);
> - }
> + bdrv_set_backing_hd(bs, backing_hd);
> + /* Now we have refcnt = 2 on backing_hd by bdrv_new and
> + * bdrv_set_backing_hd, while we only need 1 */
> + assert(backing_hd->refcnt == 2);
> + bdrv_unref(backing_hd);
It is a bit worrisome to manually track refcnt like this, and I think
it might be red flag that bdrv_set_backing_hd() isn't entirely
correct. It seems wrong (and a bit fragile) to have to compensate for
what is essentially a spurious bdrv_ref() call by another function.
Also, this relies on implicit knowledge that bdrv_set_backing_hd()
increases the refcnt, and that the refcnt is increased only once in
bdrv_set_backing_fd().
>
> /* Recalculate the BlockLimits with the backing file */
> bdrv_refresh_limits(bs);
> @@ -1923,7 +1953,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
>
> /* The contents of 'tmp' will become bs_top, as we are
> * swapping bs_new and bs_top contents. */
> - bs_top->backing_hd = bs_new;
> + bdrv_set_backing_hd(bs_top, bs_new);
If the bs_top->backing_hd is NULL, this means the refcnt on bs_new is
off by one now, right? And I think in the current usage,
bs_top->backing_hd will always be NULL here.
> bs_top->open_flags &= ~BDRV_O_NO_BACKING;
Hmm, this should probably be in bdrv_set_backing_hd() for any non-NULL
backing_hd value.
> pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file),
> bs_new->filename);
This line, and the one below it (not in the diff context) are now
redundant, and should be removed.
> diff --git a/include/block/block.h b/include/block/block.h
> index a46f70a..ee1582d 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -208,6 +208,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags);
> int bdrv_open_image(BlockDriverState **pbs, const char *filename,
> QDict *options, const char *bdref_key, int flags,
> bool allow_none, Error **errp);
> +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
> int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp);
> int bdrv_open(BlockDriverState **pbs, const char *filename,
> const char *reference, QDict *options, int flags,
> --
> 1.8.5.4
>
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd()
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd() Fam Zheng
2014-02-26 21:45 ` Jeff Cody
@ 2014-02-26 22:35 ` Jeff Cody
2014-03-07 7:53 ` Fam Zheng
1 sibling, 1 reply; 22+ messages in thread
From: Jeff Cody @ 2014-02-26 22:35 UTC (permalink / raw)
To: Fam Zheng
Cc: kwolf, benoit.canet, rjones, qemu-devel, armbru, imain, stefanha,
pbonzini, ptoscano
On Sun, Feb 23, 2014 at 09:54:46AM +0800, Fam Zheng wrote:
> This is the common but non-trivial steps to assign or change the
> backing_hd of BDS.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
> block.c | 46 ++++++++++++++++++++++++++++++++++++++--------
> include/block/block.h | 1 +
> 2 files changed, 39 insertions(+), 8 deletions(-)
>
> diff --git a/block.c b/block.c
> index 684b9d6..9caade9 100644
> --- a/block.c
> +++ b/block.c
> @@ -1041,6 +1041,32 @@ fail:
> return ret;
> }
>
> +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
> +{
> + if (backing_hd) {
> + /* Grab the reference before unref original backing_hd, so we are safe
> + * when rebasing in the backing chain.
> + */
> + bdrv_ref(backing_hd);
I think the problem is performing this bdrv_ref() makes the
assumptions that:
A) bs->backing_hd is non-NULL, and
B) backing_hd is currently a backing file, at some level, of
bs->backing_chain.
The above conditions are not always true, which is what led to my
concerns in my previous email. I think we could avoid the spurious
bdrv_ref() if we check for both conditions A and B before calling
bdrv_ref(backing_hd).
But I think there could still be a problem...
> + }
> +
> + if (bs->backing_hd) {
> + bdrv_unref(bs->backing_hd);
Only if conditions A and B are true would this bdrv_unref()
potentially lead to a bdrv_unref() being called on backing_hd.
But what if the refcnt on bs->backing_hd is > 1? Then even if
conditions A and B are met, we still won't eventually unref
backing_hd, making the bdrv_ref(backing_hd) spurious.
But as I mentioned before, manually checking refcnt, or making
assumptions on refcnt, seems very wrong.
It is almost like what is needed, are some conditional refcnt
implementations. Something like:
void bdrv_cond_ref(BlockDriverState *bs_cond, BlockDriverState *bs)
That would increase the refcnt on bs_cond IFF:
1) bs is non-NULL
2) bs_cond is in the backing chain of bs
3) bs is at risk of deletion on the next unref
> + }
> +
> + bs->backing_hd = backing_hd;
> + if (!backing_hd) {
> + bs->backing_file[0] = '\0';
> + bs->backing_format[0] = '\0';
> + goto out;
> + }
> + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
> + pstrcpy(bs->backing_format, sizeof(bs->backing_format),
> + backing_hd->drv ? backing_hd->drv->format_name : "");
> +out:
> + bdrv_refresh_limits(bs);
> +}
> +
> /*
> * Opens the backing file for a BlockDriverState if not yet open
> *
> @@ -1054,6 +1080,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
> char backing_filename[PATH_MAX];
> int back_flags, ret;
> BlockDriver *back_drv = NULL;
> + BlockDriverState *backing_hd;
> Error *local_err = NULL;
>
> if (bs->backing_hd != NULL) {
> @@ -1077,6 +1104,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
> sizeof(backing_filename));
> }
>
> + backing_hd = bdrv_new("");
> +
> if (bs->backing_format[0] != '\0') {
> back_drv = bdrv_find_format(bs->backing_format);
> }
> @@ -1085,23 +1114,24 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
> back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT |
> BDRV_O_COPY_ON_READ);
>
> - assert(bs->backing_hd == NULL);
> - ret = bdrv_open(&bs->backing_hd,
> + ret = bdrv_open(&backing_hd,
> *backing_filename ? backing_filename : NULL, NULL, options,
> back_flags, back_drv, &local_err);
> if (ret < 0) {
> bs->backing_hd = NULL;
> + bdrv_unref(backing_hd);
> + backing_hd = NULL;
> bs->open_flags |= BDRV_O_NO_BACKING;
> error_setg(errp, "Could not open backing file: %s",
> error_get_pretty(local_err));
> error_free(local_err);
> return ret;
> }
> -
> - if (bs->backing_hd->file) {
> - pstrcpy(bs->backing_file, sizeof(bs->backing_file),
> - bs->backing_hd->file->filename);
> - }
> + bdrv_set_backing_hd(bs, backing_hd);
> + /* Now we have refcnt = 2 on backing_hd by bdrv_new and
> + * bdrv_set_backing_hd, while we only need 1 */
> + assert(backing_hd->refcnt == 2);
> + bdrv_unref(backing_hd);
>
> /* Recalculate the BlockLimits with the backing file */
> bdrv_refresh_limits(bs);
> @@ -1923,7 +1953,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
>
> /* The contents of 'tmp' will become bs_top, as we are
> * swapping bs_new and bs_top contents. */
> - bs_top->backing_hd = bs_new;
> + bdrv_set_backing_hd(bs_top, bs_new);
> bs_top->open_flags &= ~BDRV_O_NO_BACKING;
> pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file),
> bs_new->filename);
> diff --git a/include/block/block.h b/include/block/block.h
> index a46f70a..ee1582d 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -208,6 +208,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags);
> int bdrv_open_image(BlockDriverState **pbs, const char *filename,
> QDict *options, const char *bdref_key, int flags,
> bool allow_none, Error **errp);
> +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
> int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp);
> int bdrv_open(BlockDriverState **pbs, const char *filename,
> const char *reference, QDict *options, int flags,
> --
> 1.8.5.4
>
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker Fam Zheng
@ 2014-02-27 12:12 ` Markus Armbruster
2014-03-07 7:50 ` Fam Zheng
0 siblings, 1 reply; 22+ messages in thread
From: Markus Armbruster @ 2014-02-27 12:12 UTC (permalink / raw)
To: Fam Zheng
Cc: kwolf, benoit.canet, qemu-devel, rjones, imain, stefanha,
pbonzini, ptoscano
Fam Zheng <famz@redhat.com> writes:
> This drops BlockDriverState.in_use with op_blockers:
>
> - Call bdrv_op_block_all in place of bdrv_set_in_use(bs, 1).
> - Call bdrv_op_unblock_all in place of bdrv_set_in_use(bs, 0).
> - Check bdrv_op_is_blocked() in place of bdrv_in_use(bs).
> The specific types are used, e.g. in place of starting block backup,
> bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP, ...).
> - Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use).
>
> Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers at
> this moment. So although the checks are specific to op types, this
> changes can still be seen as identical logic with previously with
> in_use. The difference is error message are improved because of blocker
> error info.
[...]
> diff --git a/blockdev.c b/blockdev.c
> index 357f760..5c5a9c4 100644
> --- a/blockdev.c
> +++ b/blockdev.c
[...]
> @@ -1723,7 +1722,7 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
> qerror_report(QERR_DEVICE_NOT_FOUND, id);
> return -1;
> }
> - if (bdrv_in_use(bs)) {
> + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, NULL)) {
> qerror_report(QERR_DEVICE_IN_USE, id);
> return -1;
> }
Loses the nice message you stored in bs->blockers[]. You could put it
to use like this:
diff --git a/blockdev.c b/blockdev.c
index 0843ca7..4ab9832 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1763,6 +1763,7 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
{
const char *id = qdict_get_str(qdict, "id");
+ Error *local_err = NULL;
BlockDriverState *bs;
bs = bdrv_find(id);
@@ -1770,8 +1771,9 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
qerror_report(QERR_DEVICE_NOT_FOUND, id);
return -1;
}
- if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, NULL)) {
- qerror_report(QERR_DEVICE_IN_USE, id);
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, &local_err)) {
+ error_report("%s", error_get_pretty(local_err));
+ error_free(local_err);
return -1;
}
I can do it on top, if you prefer.
[...]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker
2014-02-27 12:12 ` Markus Armbruster
@ 2014-03-07 7:50 ` Fam Zheng
0 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-03-07 7:50 UTC (permalink / raw)
To: Markus Armbruster
Cc: kwolf, benoit.canet, qemu-devel, rjones, imain, stefanha,
pbonzini, ptoscano
On Thu, 02/27 13:12, Markus Armbruster wrote:
> Fam Zheng <famz@redhat.com> writes:
>
> > This drops BlockDriverState.in_use with op_blockers:
> >
> > - Call bdrv_op_block_all in place of bdrv_set_in_use(bs, 1).
> > - Call bdrv_op_unblock_all in place of bdrv_set_in_use(bs, 0).
> > - Check bdrv_op_is_blocked() in place of bdrv_in_use(bs).
> > The specific types are used, e.g. in place of starting block backup,
> > bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP, ...).
> > - Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use).
> >
> > Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers at
> > this moment. So although the checks are specific to op types, this
> > changes can still be seen as identical logic with previously with
> > in_use. The difference is error message are improved because of blocker
> > error info.
> [...]
> > diff --git a/blockdev.c b/blockdev.c
> > index 357f760..5c5a9c4 100644
> > --- a/blockdev.c
> > +++ b/blockdev.c
> [...]
> > @@ -1723,7 +1722,7 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
> > qerror_report(QERR_DEVICE_NOT_FOUND, id);
> > return -1;
> > }
> > - if (bdrv_in_use(bs)) {
> > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, NULL)) {
> > qerror_report(QERR_DEVICE_IN_USE, id);
> > return -1;
> > }
>
> Loses the nice message you stored in bs->blockers[]. You could put it
> to use like this:
>
> diff --git a/blockdev.c b/blockdev.c
> index 0843ca7..4ab9832 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1763,6 +1763,7 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
> int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
> {
> const char *id = qdict_get_str(qdict, "id");
> + Error *local_err = NULL;
> BlockDriverState *bs;
>
> bs = bdrv_find(id);
> @@ -1770,8 +1771,9 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
> qerror_report(QERR_DEVICE_NOT_FOUND, id);
> return -1;
> }
> - if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, NULL)) {
> - qerror_report(QERR_DEVICE_IN_USE, id);
> + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, &local_err)) {
> + error_report("%s", error_get_pretty(local_err));
> + error_free(local_err);
> return -1;
> }
>
> I can do it on top, if you prefer.
>
Nice. Thanks, will update this patch when respin.
Fam
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd()
2014-02-26 22:35 ` Jeff Cody
@ 2014-03-07 7:53 ` Fam Zheng
0 siblings, 0 replies; 22+ messages in thread
From: Fam Zheng @ 2014-03-07 7:53 UTC (permalink / raw)
To: Jeff Cody
Cc: kwolf, benoit.canet, rjones, qemu-devel, armbru, imain, stefanha,
pbonzini, ptoscano
On Wed, 02/26 17:35, Jeff Cody wrote:
> On Sun, Feb 23, 2014 at 09:54:46AM +0800, Fam Zheng wrote:
> > This is the common but non-trivial steps to assign or change the
> > backing_hd of BDS.
> >
> > Signed-off-by: Fam Zheng <famz@redhat.com>
> > ---
> > block.c | 46 ++++++++++++++++++++++++++++++++++++++--------
> > include/block/block.h | 1 +
> > 2 files changed, 39 insertions(+), 8 deletions(-)
> >
> > diff --git a/block.c b/block.c
> > index 684b9d6..9caade9 100644
> > --- a/block.c
> > +++ b/block.c
> > @@ -1041,6 +1041,32 @@ fail:
> > return ret;
> > }
> >
> > +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
> > +{
> > + if (backing_hd) {
> > + /* Grab the reference before unref original backing_hd, so we are safe
> > + * when rebasing in the backing chain.
> > + */
> > + bdrv_ref(backing_hd);
>
> I think the problem is performing this bdrv_ref() makes the
> assumptions that:
>
> A) bs->backing_hd is non-NULL, and
> B) backing_hd is currently a backing file, at some level, of
> bs->backing_chain.
>
> The above conditions are not always true, which is what led to my
> concerns in my previous email. I think we could avoid the spurious
> bdrv_ref() if we check for both conditions A and B before calling
> bdrv_ref(backing_hd).
>
> But I think there could still be a problem...
>
> > + }
> > +
> > + if (bs->backing_hd) {
> > + bdrv_unref(bs->backing_hd);
>
> Only if conditions A and B are true would this bdrv_unref()
> potentially lead to a bdrv_unref() being called on backing_hd.
>
> But what if the refcnt on bs->backing_hd is > 1? Then even if
> conditions A and B are met, we still won't eventually unref
> backing_hd, making the bdrv_ref(backing_hd) spurious.
>
> But as I mentioned before, manually checking refcnt, or making
> assumptions on refcnt, seems very wrong.
>
> It is almost like what is needed, are some conditional refcnt
> implementations. Something like:
>
> void bdrv_cond_ref(BlockDriverState *bs_cond, BlockDriverState *bs)
>
> That would increase the refcnt on bs_cond IFF:
>
> 1) bs is non-NULL
> 2) bs_cond is in the backing chain of bs
> 3) bs is at risk of deletion on the next unref
>
I see the problem, however these rules (bdrv_cond_ref) still look hard to
infer.
To keep it simple, I prefer to remove bdrv_ref/bdrv_unref in
bdrv_set_backing_hd and leave it to caller, which is the most readable I think.
Fam
^ permalink raw reply [flat|nested] 22+ messages in thread
end of thread, other threads:[~2014-03-07 7:53 UTC | newest]
Thread overview: 22+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-02-23 1:54 [Qemu-devel] [PATCH v15 00/14] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 01/14] block: Add BlockOpType enum Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 02/14] block: Introduce op_blockers to BlockDriverState Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 03/14] block: Replace in_use with operation blocker Fam Zheng
2014-02-27 12:12 ` Markus Armbruster
2014-03-07 7:50 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 04/14] block: Move op_blocker check from block_job_create to its caller Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 05/14] block: Add bdrv_set_backing_hd() Fam Zheng
2014-02-26 21:45 ` Jeff Cody
2014-02-26 22:35 ` Jeff Cody
2014-03-07 7:53 ` Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 06/14] block: Add backing_blocker in BlockDriverState Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 07/14] block: Parse "backing" option to reference existing BDS Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 08/14] block: Support dropping active in bdrv_drop_intermediate Fam Zheng
2014-02-26 19:42 ` Jeff Cody
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 09/14] stream: Use bdrv_drop_intermediate and drop close_unused_images Fam Zheng
2014-02-26 20:31 ` Jeff Cody
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 10/14] qmp: Add command 'blockdev-backup' Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 11/14] block: Allow backup on referenced named BlockDriverState Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 12/14] block: Add blockdev-backup to transaction Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 13/14] qemu-iotests: Test blockdev-backup in 055 Fam Zheng
2014-02-23 1:54 ` [Qemu-devel] [PATCH v15 14/14] qemu-iotests: Image fleecing test case 083 Fam Zheng
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