similarity index 56%
rename from block/backup-top.h
rename to block/copy-before-write.h
@@ -1,10 +1,10 @@
/*
- * backup-top filter driver
+ * copy-before-write filter driver
*
* The driver performs Copy-Before-Write (CBW) operation: it is injected above
* some node, and before each write it copies _old_ data to the target node.
*
- * Copyright (c) 2018-2019 Virtuozzo International GmbH.
+ * Copyright (c) 2018-2021 Virtuozzo International GmbH.
*
* Author:
* Sementsov-Ogievskiy Vladimir <vsementsov@virtuozzo.com>
@@ -23,20 +23,20 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#ifndef BACKUP_TOP_H
-#define BACKUP_TOP_H
+#ifndef COPY_BEFORE_WRITE_H
+#define COPY_BEFORE_WRITE_H
#include "block/block_int.h"
#include "block/block-copy.h"
-BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
- BlockDriverState *target,
- const char *filter_node_name,
- uint64_t cluster_size,
- BackupPerf *perf,
- BdrvRequestFlags write_flags,
- BlockCopyState **bcs,
- Error **errp);
-void bdrv_backup_top_drop(BlockDriverState *bs);
+BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
+ BlockDriverState *target,
+ const char *filter_node_name,
+ uint64_t cluster_size,
+ BackupPerf *perf,
+ BdrvRequestFlags write_flags,
+ BlockCopyState **bcs,
+ Error **errp);
+void bdrv_cbw_drop(BlockDriverState *bs);
-#endif /* BACKUP_TOP_H */
+#endif /* COPY_BEFORE_WRITE_H */
@@ -27,13 +27,13 @@
#include "qemu/bitmap.h"
#include "qemu/error-report.h"
-#include "block/backup-top.h"
+#include "block/copy-before-write.h"
#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
typedef struct BackupBlockJob {
BlockJob common;
- BlockDriverState *backup_top;
+ BlockDriverState *cbw;
BlockDriverState *source_bs;
BlockDriverState *target_bs;
@@ -104,7 +104,7 @@ static void backup_clean(Job *job)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
block_job_remove_all_bdrv(&s->common);
- bdrv_backup_top_drop(s->backup_top);
+ bdrv_cbw_drop(s->cbw);
}
void backup_do_checkpoint(BlockJob *job, Error **errp)
@@ -408,7 +408,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
BackupBlockJob *job = NULL;
int64_t cluster_size;
BdrvRequestFlags write_flags;
- BlockDriverState *backup_top = NULL;
+ BlockDriverState *cbw = NULL;
BlockCopyState *bcs = NULL;
assert(bs);
@@ -521,22 +521,22 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
write_flags = (bdrv_chain_contains(target, bs) ? BDRV_REQ_SERIALISING : 0) |
(compress ? BDRV_REQ_WRITE_COMPRESSED : 0),
- backup_top = bdrv_backup_top_append(bs, target, filter_node_name,
+ cbw = bdrv_cbw_append(bs, target, filter_node_name,
cluster_size, perf,
write_flags, &bcs, errp);
- if (!backup_top) {
+ if (!cbw) {
goto error;
}
/* job->len is fixed, so we can't allow resize */
- job = block_job_create(job_id, &backup_job_driver, txn, backup_top,
+ job = block_job_create(job_id, &backup_job_driver, txn, cbw,
0, BLK_PERM_ALL,
speed, creation_flags, cb, opaque, errp);
if (!job) {
goto error;
}
- job->backup_top = backup_top;
+ job->cbw = cbw;
job->source_bs = bs;
job->target_bs = target;
job->on_source_error = on_source_error;
@@ -552,7 +552,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
block_copy_set_progress_meter(bcs, &job->common.job.progress);
block_copy_set_speed(bcs, speed);
- /* Required permissions are already taken by backup-top target */
+ /* Required permissions are taken by copy-before-write filter target */
block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
&error_abort);
@@ -562,8 +562,8 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
if (sync_bitmap) {
bdrv_reclaim_dirty_bitmap(sync_bitmap, NULL);
}
- if (backup_top) {
- bdrv_backup_top_drop(backup_top);
+ if (cbw) {
+ bdrv_cbw_drop(cbw);
}
return NULL;
similarity index 62%
rename from block/backup-top.c
rename to block/copy-before-write.c
@@ -1,10 +1,10 @@
/*
- * backup-top filter driver
+ * copy-before-write filter driver
*
* The driver performs Copy-Before-Write (CBW) operation: it is injected above
* some node, and before each write it copies _old_ data to the target node.
*
- * Copyright (c) 2018-2019 Virtuozzo International GmbH.
+ * Copyright (c) 2018-2021 Virtuozzo International GmbH.
*
* Author:
* Sementsov-Ogievskiy Vladimir <vsementsov@virtuozzo.com>
@@ -32,25 +32,25 @@
#include "block/qdict.h"
#include "block/block-copy.h"
-#include "block/backup-top.h"
+#include "block/copy-before-write.h"
-typedef struct BDRVBackupTopState {
+typedef struct BDRVCopyBeforeWriteState {
BlockCopyState *bcs;
BdrvChild *target;
int64_t cluster_size;
-} BDRVBackupTopState;
+} BDRVCopyBeforeWriteState;
-static coroutine_fn int backup_top_co_preadv(
+static coroutine_fn int cbw_co_preadv(
BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
}
-static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, BdrvRequestFlags flags)
+static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes, BdrvRequestFlags flags)
{
- BDRVBackupTopState *s = bs->opaque;
+ BDRVCopyBeforeWriteState *s = bs->opaque;
uint64_t off, end;
if (flags & BDRV_REQ_WRITE_UNCHANGED) {
@@ -63,10 +63,10 @@ static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
return block_copy(s->bcs, off, end - off, true);
}
-static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
- int64_t offset, int bytes)
+static int coroutine_fn cbw_co_pdiscard(BlockDriverState *bs,
+ int64_t offset, int bytes)
{
- int ret = backup_top_cbw(bs, offset, bytes, 0);
+ int ret = cbw_do_copy_before_write(bs, offset, bytes, 0);
if (ret < 0) {
return ret;
}
@@ -74,10 +74,10 @@ static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
return bdrv_co_pdiscard(bs->backing, offset, bytes);
}
-static int coroutine_fn backup_top_co_pwrite_zeroes(BlockDriverState *bs,
+static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs,
int64_t offset, int bytes, BdrvRequestFlags flags)
{
- int ret = backup_top_cbw(bs, offset, bytes, flags);
+ int ret = cbw_do_copy_before_write(bs, offset, bytes, flags);
if (ret < 0) {
return ret;
}
@@ -85,12 +85,12 @@ static int coroutine_fn backup_top_co_pwrite_zeroes(BlockDriverState *bs,
return bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags);
}
-static coroutine_fn int backup_top_co_pwritev(BlockDriverState *bs,
- uint64_t offset,
- uint64_t bytes,
- QEMUIOVector *qiov, int flags)
+static coroutine_fn int cbw_co_pwritev(BlockDriverState *bs,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov, int flags)
{
- int ret = backup_top_cbw(bs, offset, bytes, flags);
+ int ret = cbw_do_copy_before_write(bs, offset, bytes, flags);
if (ret < 0) {
return ret;
}
@@ -98,7 +98,7 @@ static coroutine_fn int backup_top_co_pwritev(BlockDriverState *bs,
return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags);
}
-static int coroutine_fn backup_top_co_flush(BlockDriverState *bs)
+static int coroutine_fn cbw_co_flush(BlockDriverState *bs)
{
if (!bs->backing) {
return 0;
@@ -107,7 +107,7 @@ static int coroutine_fn backup_top_co_flush(BlockDriverState *bs)
return bdrv_co_flush(bs->backing->bs);
}
-static void backup_top_refresh_filename(BlockDriverState *bs)
+static void cbw_refresh_filename(BlockDriverState *bs)
{
if (bs->backing == NULL) {
/*
@@ -120,11 +120,11 @@ static void backup_top_refresh_filename(BlockDriverState *bs)
bs->backing->bs->filename);
}
-static void backup_top_child_perm(BlockDriverState *bs, BdrvChild *c,
- BdrvChildRole role,
- BlockReopenQueue *reopen_queue,
- uint64_t perm, uint64_t shared,
- uint64_t *nperm, uint64_t *nshared)
+static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c,
+ BdrvChildRole role,
+ BlockReopenQueue *reopen_queue,
+ uint64_t perm, uint64_t shared,
+ uint64_t *nperm, uint64_t *nshared)
{
if (!(role & BDRV_CHILD_FILTERED)) {
/*
@@ -149,41 +149,41 @@ static void backup_top_child_perm(BlockDriverState *bs, BdrvChild *c,
}
}
-BlockDriver bdrv_backup_top_filter = {
- .format_name = "backup-top",
- .instance_size = sizeof(BDRVBackupTopState),
+BlockDriver bdrv_cbw_filter = {
+ .format_name = "copy-before-write",
+ .instance_size = sizeof(BDRVCopyBeforeWriteState),
- .bdrv_co_preadv = backup_top_co_preadv,
- .bdrv_co_pwritev = backup_top_co_pwritev,
- .bdrv_co_pwrite_zeroes = backup_top_co_pwrite_zeroes,
- .bdrv_co_pdiscard = backup_top_co_pdiscard,
- .bdrv_co_flush = backup_top_co_flush,
+ .bdrv_co_preadv = cbw_co_preadv,
+ .bdrv_co_pwritev = cbw_co_pwritev,
+ .bdrv_co_pwrite_zeroes = cbw_co_pwrite_zeroes,
+ .bdrv_co_pdiscard = cbw_co_pdiscard,
+ .bdrv_co_flush = cbw_co_flush,
- .bdrv_refresh_filename = backup_top_refresh_filename,
+ .bdrv_refresh_filename = cbw_refresh_filename,
- .bdrv_child_perm = backup_top_child_perm,
+ .bdrv_child_perm = cbw_child_perm,
.is_filter = true,
};
-BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
- BlockDriverState *target,
- const char *filter_node_name,
- uint64_t cluster_size,
- BackupPerf *perf,
- BdrvRequestFlags write_flags,
- BlockCopyState **bcs,
- Error **errp)
+BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
+ BlockDriverState *target,
+ const char *filter_node_name,
+ uint64_t cluster_size,
+ BackupPerf *perf,
+ BdrvRequestFlags write_flags,
+ BlockCopyState **bcs,
+ Error **errp)
{
ERRP_GUARD();
int ret;
- BDRVBackupTopState *state;
+ BDRVCopyBeforeWriteState *state;
BlockDriverState *top;
bool appended = false;
assert(source->total_sectors == target->total_sectors);
- top = bdrv_new_open_driver(&bdrv_backup_top_filter, filter_node_name,
+ top = bdrv_new_open_driver(&bdrv_cbw_filter, filter_node_name,
BDRV_O_RDWR, errp);
if (!top) {
return NULL;
@@ -210,7 +210,7 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
ret = bdrv_append(top, source, errp);
if (ret < 0) {
- error_prepend(errp, "Cannot append backup-top filter: ");
+ error_prepend(errp, "Cannot append copy-before-write filter: ");
goto fail;
}
appended = true;
@@ -231,7 +231,7 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
fail:
if (appended) {
- bdrv_backup_top_drop(top);
+ bdrv_cbw_drop(top);
} else {
bdrv_unref(top);
}
@@ -241,9 +241,9 @@ fail:
return NULL;
}
-void bdrv_backup_top_drop(BlockDriverState *bs)
+void bdrv_cbw_drop(BlockDriverState *bs)
{
- BDRVBackupTopState *s = bs->opaque;
+ BDRVCopyBeforeWriteState *s = bs->opaque;
bdrv_drop_filter(bs, &error_abort);
@@ -2342,8 +2342,8 @@ F: block/mirror.c
F: qapi/job.json
F: block/block-copy.c
F: include/block/block-copy.c
-F: block/backup-top.h
-F: block/backup-top.c
+F: block/copy-before-write.h
+F: block/copy-before-write.c
F: include/block/aio_task.h
F: block/aio_task.c
F: util/qemu-co-shared-resource.c
@@ -4,7 +4,7 @@ block_ss.add(files(
'aio_task.c',
'amend.c',
'backup.c',
- 'backup-top.c',
+ 'copy-before-write.c',
'blkdebug.c',
'blklogwrites.c',
'blkverify.c',
@@ -1,7 +1,7 @@
#!/usr/bin/env python3
# group: auto quick
#
-# Test for backup-top filter permission activation failure
+# Test for copy-before-write filter permission conflict
#
# Copyright (c) 2019 Virtuozzo International GmbH.
#
@@ -31,13 +31,13 @@ size = 1024 * 1024
""" Test description
When performing a backup, all writes on the source subtree must go through the
-backup-top filter so it can copy all data to the target before it is changed.
-backup-top filter is appended above source node, to achieve this thing, so all
-parents of source node are handled. A configuration with side parents of source
-sub-tree with write permission is unsupported (we'd have append several
-backup-top filter like nodes to handle such parents). The test create an
-example of such configuration and checks that a backup is then not allowed
-(blockdev-backup command should fail).
+copy-before-write filter so it can copy all data to the target before it is
+changed. copy-before-write filter is appended above source node, to achieve
+this thing, so all parents of source node are handled. A configuration with
+side parents of source sub-tree with write permission is unsupported (we'd have
+append several copy-before-write filter like nodes to handle such parents). The
+test create an example of such configuration and checks that a backup is then
+not allowed (blockdev-backup command should fail).
The configuration:
@@ -57,11 +57,10 @@ The configuration:
│ base │ ◀──────────── │ other │
└─────────────┘ └───────┘
-On activation (see .active field of backup-top state in block/backup-top.c),
-backup-top is going to unshare write permission on its source child. Write
-unsharing will be propagated to the "source->base" link and will conflict with
-other node write permission. So permission update will fail and backup job will
-not be started.
+copy-before-write filter wants to unshare write permission on its source child.
+Write unsharing will be propagated to the "source->base" link and will conflict
+with other node write permission. So permission update will fail and backup job
+will not be started.
Note, that the only thing which prevents backup of running on such
configuration is default permission propagation scheme. It may be altered by
@@ -99,13 +98,9 @@ vm.qmp_log('blockdev-backup', sync='full', device='source', target='target')
vm.shutdown()
-print('\n=== backup-top should be gone after job-finalize ===\n')
+print('\n=== copy-before-write filter should be gone after job-finalize ===\n')
-# Check that the backup-top node is gone after job-finalize.
-#
-# During finalization, the node becomes inactive and can no longer
-# function. If it is still present, new parents might be attached, and
-# there would be no meaningful way to handle their I/O requests.
+# Check that the copy-before-write node is gone after job-finalize.
vm = iotests.VM()
vm.launch()
@@ -131,7 +126,7 @@ vm.qmp_log('blockdev-backup',
vm.event_wait('BLOCK_JOB_PENDING', 5.0)
-# The backup-top filter should still be present prior to finalization
+# The copy-before-write filter should still be present prior to finalization
assert vm.node_info('backup-filter') is not None
vm.qmp_log('job-finalize', id='backup')
@@ -5,9 +5,9 @@
{"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}}
{"return": {}}
{"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}}
-{"error": {"class": "GenericError", "desc": "Cannot append backup-top filter: Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}}
+{"error": {"class": "GenericError", "desc": "Cannot append copy-before-write filter: Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}}
-=== backup-top should be gone after job-finalize ===
+=== copy-before-write filter should be gone after job-finalize ===
{"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "source"}}
{"return": {}}