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block: Use BlockBackend for I/O in bdrv_commit()

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Just like block jobs, the HMP commit command should use its own
BlockBackend for doing I/O on BlockDriverStates.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2016-05-30 16:29:47 +02:00
parent 83fd6dd3e7
commit f8e2bd538d
1 changed files with 22 additions and 12 deletions
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34
block/commit.c
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@ -289,6 +289,7 @@ void commit_start(BlockDriverState *bs, BlockDriverState *base,
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
BlockBackend *src, *backing;
BlockDriver *drv = bs->drv;
int64_t sector, total_sectors, length, backing_length;
int n, ro, open_flags;
@ -316,13 +317,19 @@ int bdrv_commit(BlockDriverState *bs)
}
}
length = bdrv_getlength(bs);
src = blk_new();
blk_insert_bs(src, bs);
backing = blk_new();
blk_insert_bs(backing, bs->backing->bs);
length = blk_getlength(src);
if (length < 0) {
ret = length;
goto ro_cleanup;
}
backing_length = bdrv_getlength(bs->backing->bs);
backing_length = blk_getlength(backing);
if (backing_length < 0) {
ret = backing_length;
goto ro_cleanup;
@ -332,7 +339,7 @@ int bdrv_commit(BlockDriverState *bs)
* grow the backing file image if possible. If not possible,
* we must return an error */
if (length > backing_length) {
ret = bdrv_truncate(bs->backing->bs, length);
ret = blk_truncate(backing, length);
if (ret < 0) {
goto ro_cleanup;
}
@ -340,9 +347,9 @@ int bdrv_commit(BlockDriverState *bs)
total_sectors = length >> BDRV_SECTOR_BITS;
/* qemu_try_blockalign() for bs will choose an alignment that works for
* bs->backing->bs as well, so no need to compare the alignment manually. */
buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
/* blk_try_blockalign() for src will choose an alignment that works for
* backing as well, so no need to compare the alignment manually. */
buf = blk_try_blockalign(src, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
if (buf == NULL) {
ret = -ENOMEM;
goto ro_cleanup;
@ -354,12 +361,14 @@ int bdrv_commit(BlockDriverState *bs)
goto ro_cleanup;
}
if (ret) {
ret = bdrv_read(bs, sector, buf, n);
ret = blk_pread(src, sector * BDRV_SECTOR_SIZE, buf,
n * BDRV_SECTOR_SIZE);
if (ret < 0) {
goto ro_cleanup;
}
ret = bdrv_write(bs->backing->bs, sector, buf, n);
ret = blk_pwrite(backing, sector * BDRV_SECTOR_SIZE, buf,
n * BDRV_SECTOR_SIZE, 0);
if (ret < 0) {
goto ro_cleanup;
}
@ -371,21 +380,22 @@ int bdrv_commit(BlockDriverState *bs)
if (ret < 0) {
goto ro_cleanup;
}
bdrv_flush(bs);
blk_flush(src);
}
/*
* Make sure all data we wrote to the backing device is actually
* stable on disk.
*/
if (bs->backing) {
bdrv_flush(bs->backing->bs);
}
blk_flush(backing);
ret = 0;
ro_cleanup:
qemu_vfree(buf);
blk_unref(src);
blk_unref(backing);
if (ro) {
/* ignoring error return here */
bdrv_reopen(bs->backing->bs, open_flags & ~BDRV_O_RDWR, NULL);