mirror of https://github.com/proxmox/mirror_qemu
block: Flush all children in generic code
If the driver does not support .bdrv_co_flush() so bdrv_co_flush() itself has to flush the children of the given node, it should not flush just bs->file->bs, but in fact all children that might have been written to (judging from the permissions taken on them). This is a bug fix for qcow2 images with an external data file, as they so far did not flush that data_file node. In any case, the BLKDBG_EVENT() should be emitted on the primary child, because that is where a blkdebug node would be if there is any. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>master
parent
1d42f48c3a
commit
883833e29c
23
block/io.c
23
block/io.c
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@ -2771,6 +2771,8 @@ static int coroutine_fn bdrv_flush_co_entry(void *opaque)
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int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
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int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
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{
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{
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BdrvChild *primary_child = bdrv_primary_child(bs);
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BdrvChild *child;
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int current_gen;
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int current_gen;
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int ret = 0;
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int ret = 0;
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@ -2800,7 +2802,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
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}
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}
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/* Write back cached data to the OS even with cache=unsafe */
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/* Write back cached data to the OS even with cache=unsafe */
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BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
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BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_OS);
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if (bs->drv->bdrv_co_flush_to_os) {
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if (bs->drv->bdrv_co_flush_to_os) {
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ret = bs->drv->bdrv_co_flush_to_os(bs);
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ret = bs->drv->bdrv_co_flush_to_os(bs);
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if (ret < 0) {
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if (ret < 0) {
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@ -2810,15 +2812,15 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
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/* But don't actually force it to the disk with cache=unsafe */
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/* But don't actually force it to the disk with cache=unsafe */
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if (bs->open_flags & BDRV_O_NO_FLUSH) {
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if (bs->open_flags & BDRV_O_NO_FLUSH) {
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goto flush_parent;
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goto flush_children;
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}
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}
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/* Check if we really need to flush anything */
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/* Check if we really need to flush anything */
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if (bs->flushed_gen == current_gen) {
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if (bs->flushed_gen == current_gen) {
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goto flush_parent;
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goto flush_children;
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}
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}
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BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
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BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_DISK);
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if (!bs->drv) {
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if (!bs->drv) {
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/* bs->drv->bdrv_co_flush() might have ejected the BDS
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/* bs->drv->bdrv_co_flush() might have ejected the BDS
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* (even in case of apparent success) */
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* (even in case of apparent success) */
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@ -2862,8 +2864,17 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
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/* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
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/* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
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* in the case of cache=unsafe, so there are no useless flushes.
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* in the case of cache=unsafe, so there are no useless flushes.
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*/
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*/
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flush_parent:
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flush_children:
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ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0;
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ret = 0;
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QLIST_FOREACH(child, &bs->children, next) {
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if (child->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
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int this_child_ret = bdrv_co_flush(child->bs);
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if (!ret) {
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ret = this_child_ret;
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}
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}
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}
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out:
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out:
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/* Notify any pending flushes that we have completed */
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/* Notify any pending flushes that we have completed */
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if (ret == 0) {
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if (ret == 0) {
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