Re: [PATCH v2] statx: stx_subvol

From: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
To: Kent Overstreet <kent.overstreet@linux.dev>
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-bcachefs@vger.kernel.org" <linux-bcachefs@vger.kernel.org>,
	"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Josef Bacik <josef@toxicpanda.com>,
	Miklos Szeredi <mszeredi@redhat.com>,
	Christian Brauner <brauner@kernel.org>,
	David Howells <dhowells@redhat.com>
Subject: Re: [PATCH v2] statx: stx_subvol
Date: Mon, 11 Mar 2024 08:12:33 +0000	[thread overview]
Message-ID: <2f598709-fccb-4364-bf15-f9c171b440aa@wdc.com> (raw)
In-Reply-To: <20240308022914.196982-1-kent.overstreet@linux.dev>

On 08.03.24 03:29, Kent Overstreet wrote:
> Add a new statx field for (sub)volume identifiers, as implemented by
> btrfs and bcachefs.
> 
> This includes bcachefs support; we'll definitely want btrfs support as
> well.

For btrfs you can add the following:


 From 82343b7cb2a947bca43234c443b9c22339367f68 Mon Sep 17 00:00:00 2001
From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Date: Mon, 11 Mar 2024 09:09:36 +0100
Subject: [PATCH] btrfs: provide subvolume id for statx

Add the inode's subvolume id to the newly proposed statx subvol field.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
  fs/btrfs/inode.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 37701531eeb1..8cf692c708d7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8779,6 +8779,9 @@ static int btrfs_getattr(struct mnt_idmap *idmap,
  	generic_fillattr(idmap, request_mask, inode, stat);
  	stat->dev = BTRFS_I(inode)->root->anon_dev;

+	stat->subvol = BTRFS_I(inode)->root->root_key.objectid;
+	stat->result_mask |= STATX_SUBVOL;
+
  	spin_lock(&BTRFS_I(inode)->lock);
  	delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
  	inode_bytes = inode_get_bytes(inode);
-- 
2.35.3


