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author | Max Reitz <mreitz@redhat.com> | 2019-06-12 18:18:05 +0200 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2020-09-07 12:31:31 +0200 |
commit | 883833e29cb800b4d92b5d4736252f4004885191 (patch) | |
tree | 515b6cce8e2981648e0a7a6b87dc8ff1798a220b /block/io.c | |
parent | 1d42f48c3a468fbf53660970d7372d0f0f9d0529 (diff) | |
download | qemu-883833e29cb800b4d92b5d4736252f4004885191.zip qemu-883833e29cb800b4d92b5d4736252f4004885191.tar.gz qemu-883833e29cb800b4d92b5d4736252f4004885191.tar.bz2 |
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>
Diffstat (limited to 'block/io.c')
-rw-r--r-- | block/io.c | 23 |
1 files changed, 17 insertions, 6 deletions
@@ -2771,6 +2771,8 @@ static int coroutine_fn bdrv_flush_co_entry(void *opaque) int coroutine_fn bdrv_co_flush(BlockDriverState *bs) { + BdrvChild *primary_child = bdrv_primary_child(bs); + BdrvChild *child; int current_gen; int ret = 0; @@ -2800,7 +2802,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) } /* Write back cached data to the OS even with cache=unsafe */ - BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); + BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_OS); if (bs->drv->bdrv_co_flush_to_os) { ret = bs->drv->bdrv_co_flush_to_os(bs); if (ret < 0) { @@ -2810,15 +2812,15 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) /* But don't actually force it to the disk with cache=unsafe */ if (bs->open_flags & BDRV_O_NO_FLUSH) { - goto flush_parent; + goto flush_children; } /* Check if we really need to flush anything */ if (bs->flushed_gen == current_gen) { - goto flush_parent; + goto flush_children; } - BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); + BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_DISK); if (!bs->drv) { /* bs->drv->bdrv_co_flush() might have ejected the BDS * (even in case of apparent success) */ @@ -2862,8 +2864,17 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH * in the case of cache=unsafe, so there are no useless flushes. */ -flush_parent: - ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0; +flush_children: + ret = 0; + QLIST_FOREACH(child, &bs->children, next) { + if (child->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) { + int this_child_ret = bdrv_co_flush(child->bs); + if (!ret) { + ret = this_child_ret; + } + } + } + out: /* Notify any pending flushes that we have completed */ if (ret == 0) { |