Re: [PATCH 0/3] btrfs: fix a couple sleeps while holding a spinlock

[Filipe Manana <fdmanana@kernel.org>]

On Wed, Jul 06, 2022 at 10:09:44AM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> After the recent conversions of a couple radix trees to XArrays, we now
> can end up attempting to sleep while holding a spinlock. This happens
> because if xa_insert() allocates memory (using GFP_NOFS) it may need to
> sleep (more likely to happen when under memory pressure). In the old
> code this did not happen because we had radix_tree_preload() called
> before taking the spinlocks.
> 
> Filipe Manana (3):
>   btrfs: fix sleep while under a spinlock when allocating delayed inode
>   btrfs: fix sleep while under a spinlock when inserting a fs root
>   btrfs: free qgroup metadata without holding the fs roots lock

David, are you going to pick these up or revert the patches that did the
radix tree to xarray conversion?

> 
>  fs/btrfs/ctree.h         |  6 +++---
>  fs/btrfs/delayed-inode.c | 24 ++++++++++++------------
>  fs/btrfs/disk-io.c       | 38 +++++++++++++++++++-------------------
>  fs/btrfs/inode.c         | 30 ++++++++++++++++--------------
>  fs/btrfs/relocation.c    | 11 +++++++----
>  fs/btrfs/transaction.c   | 14 +++++++-------
>  6 files changed, 64 insertions(+), 59 deletions(-)
> 
> -- 
> 2.35.1
>