We will copy data in before_write_notifier to do backup.
It is a nested I/O request, so we cannot do copy-on-read.
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
---
block/backup.c | 19 +++++++++++++------
block/io.c | 11 ++++++++++-
include/block/block.h | 3 +++
trace-events | 1 +
4 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/block/backup.c b/block/backup.c
index 965654d..b729c4b 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -89,7 +89,8 @@ static void cow_request_end(CowRequest *req)
static int coroutine_fn backup_do_cow(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
- bool *error_is_read)
+ bool *error_is_read,
+ bool is_write_notifier)
{
BackupBlockJob *job = (BackupBlockJob *)bs->job;
CowRequest cow_request;
@@ -129,8 +130,13 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs,
iov.iov_len = n * BDRV_SECTOR_SIZE;
qemu_iovec_init_external(&bounce_qiov, &iov, 1);
- ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n,
- &bounce_qiov);
+ if (is_write_notifier) {
+ ret = bdrv_co_nested_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER,
+ n, &bounce_qiov);
+ } else {
+ ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n,
+ &bounce_qiov);
+ }
if (ret < 0) {
trace_backup_do_cow_read_fail(job, start, ret);
if (error_is_read) {
@@ -190,7 +196,7 @@ static int coroutine_fn backup_before_write_notify(
assert((req->offset & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((req->bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- return backup_do_cow(req->bs, sector_num, nb_sectors, NULL);
+ return backup_do_cow(req->bs, sector_num, nb_sectors, NULL, true);
}
static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp)
@@ -303,7 +309,8 @@ static int coroutine_fn
backup_run_incremental(BackupBlockJob *job)
return ret;
}
ret = backup_do_cow(bs, cluster * BACKUP_SECTORS_PER_CLUSTER,
- BACKUP_SECTORS_PER_CLUSTER,
&error_is_read);
+ BACKUP_SECTORS_PER_CLUSTER, &error_is_read,
+ false);
if ((ret < 0) &&
backup_error_action(job, error_is_read, -ret) ==
BLOCK_ERROR_ACTION_REPORT) {
@@ -408,7 +415,7 @@ static void coroutine_fn backup_run(void *opaque)
}
/* FULL sync mode we copy the whole drive. */
ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER,
- BACKUP_SECTORS_PER_CLUSTER, &error_is_read);
+ BACKUP_SECTORS_PER_CLUSTER, &error_is_read, false);
if (ret < 0) {
/* Depending on error action, fail now or retry cluster */
BlockErrorAction action =
diff --git a/block/io.c b/block/io.c
index d4bc83b..04325f9 100644
--- a/block/io.c
+++ b/block/io.c
@@ -932,7 +932,8 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState
*bs,
return ret;
}
- if (bs->copy_on_read) {
+ /* Don't do copy-on-read if we read data before write operation */
+ if (bs->copy_on_read && !(flags & BDRV_REQ_NESTED)) {
flags |= BDRV_REQ_COPY_ON_READ;
}
@@ -1001,6 +1002,14 @@ int coroutine_fn bdrv_co_readv(BlockDriverState *bs,
int64_t sector_num,
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
}
+int coroutine_fn bdrv_co_nested_readv(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+{
+ trace_bdrv_co_nested_readv(bs, sector_num, nb_sectors);
+
+ return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, BDRV_REQ_NESTED);
+}
+
int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
diff --git a/include/block/block.h b/include/block/block.h
index 608cd4e..f5578b2 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -60,6 +60,7 @@ typedef enum {
* opened with BDRV_O_UNMAP.
*/
BDRV_REQ_MAY_UNMAP = 0x4,
+ BDRV_REQ_NESTED = 0x8,
} BdrvRequestFlags;
typedef struct BlockSizes {
@@ -253,6 +254,8 @@ int coroutine_fn bdrv_co_readv(BlockDriverState *bs,
int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
+int coroutine_fn bdrv_co_nested_readv(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov);
/*
diff --git a/trace-events b/trace-events
index 8f9614a..e29e1cf 100644
--- a/trace-events
+++ b/trace-events
@@ -69,6 +69,7 @@ bdrv_aio_write_zeroes(void *bs, int64_t sector_num, int
nb_sectors, int flags, v
bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
bdrv_co_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num
%"PRId64" nb_sectors %d"
bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p
sector_num %"PRId64" nb_sectors %d"
+bdrv_co_nested_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p
sector_num %"PRId64" nb_sectors %d"
bdrv_co_writev(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num
%"PRId64" nb_sectors %d"
bdrv_co_write_zeroes(void *bs, int64_t sector_num, int nb_sector, int flags)
"bs %p sector_num %"PRId64" nb_sectors %d flags %#x"
bdrv_co_io_em(void *bs, int64_t sector_num, int nb_sectors, int is_write, void
*acb) "bs %p sector_num %"PRId64" nb_sectors %d is_write %d acb %p"
--
2.4.3
