btrfs: add extra warning when qgroup is marked inconsistent

Unlike qgroup rescan, which always shows whether it cleared the
inconsistent flag, we do not have a proper way to show if qgroup is
marked inconsistent.

This was not a big deal before as there aren't that many locations that
can mark qgroup inconsistent.

But with the introduction of drop_subtree_threshold, qgroup can be
marked inconsistent very frequently, especially when dropping
subvolumes.

Although most user space tools relying on qgroup should do their own
checks and queue a rescan if needed, we have no idea when qgroup is
marked inconsistent, and this would be much harder to debug.

So this patch will add an extra warning (btrfs_warn_rl()) when the
qgroup flag is flipped into inconsistent for the first time.
And add extra reason why qgroup flips inconsistent.

This means we can move the error message immediately before
qgroup_inconsistent_warning() into that function.

For call sites without an obvious reason, or is a shared error handling,
output the function that failed and the error code instead.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

0 files changed, 0 insertions, 0 deletions