4.9-stable review patch. If anyone has any objections, please let me know.
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From: Misono Tomohiro misono.tomohiro@jp.fujitsu.com
[ Upstream commit 1e7e1f9e3aba00c9b9c323bfeeddafe69ff21ff6 ]
on-disk devs stats value is updated in btrfs_run_dev_stats(), which is called during commit transaction, if device->dev_stats_ccnt is not zero.
Since current replace operation does not touch dev_stats_ccnt, on-disk dev stats value is not updated. Therefore "btrfs device stats" may return old device's value after umount/mount (Example: See "btrfs ins dump-t -t DEV $DEV" after btrfs/100 finish).
Fix this by just incrementing dev_stats_ccnt in btrfs_dev_replace_finishing() when replace is succeeded and this will update the values.
Signed-off-by: Misono Tomohiro misono.tomohiro@jp.fujitsu.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/dev-replace.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -586,6 +586,12 @@ static int btrfs_dev_replace_finishing(s btrfs_rm_dev_replace_unblocked(fs_info);
/* + * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will + * update on-disk dev stats value during commit transaction + */ + atomic_inc(&tgt_device->dev_stats_ccnt); + + /* * this is again a consistent state where no dev_replace procedure * is running, the target device is part of the filesystem, the * source device is not part of the filesystem anymore and its 1st