Re: [PATCH v2 0/2] Free space tree space reservation fixes

From: David Sterba <dsterba@suse.cz>
To: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH v2 0/2] Free space tree space reservation fixes
Date: Tue, 7 Dec 2021 19:59:36 +0100	[thread overview]
Message-ID: <20211207185936.GB28560@twin.jikos.cz> (raw)
In-Reply-To: <cover.1638477127.git.josef@toxicpanda.com>

On Thu, Dec 02, 2021 at 03:34:30PM -0500, Josef Bacik wrote:
> v1->v2:
> - Updated the changelog for "btrfs: reserve extra space for free space tree" to
>   make it clear why we're doubling the space reservation per Nikolay's request.
> 
> --- Original email ---
> Hello,
> 
> Filipe reported a problem where he was getting an ENOSPC abort when running
> delayed refs for generic/619.  This is because of two reasons, first generic/619
> creates a very small file system, and our global block rsv calculation doesn't
> take into account the size of the free space tree.  Thus we could get into a
> situation where the global block rsv was not enough to handle the overflow.
> 
> The second is because we simply do not reserve space for the free space tree
> modifications.  Fix this by making sure any free space tree root has their block
> rsv set to the delayed refs rsv, and then make sure if we have the free space
> tree enabled we're reserving extra space for those operations.
> 
> With these patches the problem Filipe was hitting went away.  Thanks,
> 
> Josef
> 
> Josef Bacik (2):
>   btrfs: include the free space tree in the global rsv minimum
>     calculation
>   btrfs: reserve extra space for the free space tree

Added to misc-next, thanks. Filipe had a question in patch 2 which I
believe has been answered, but if there's anything to add/update please
let me know.