[PATCH v2 09/10] porting: document block device freeze and thaw changes

From: Christian Brauner <brauner@kernel.org>
To: Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@lst.de>,
	 "Darrick J. Wong" <djwong@kernel.org>
Cc: linux-fsdevel@vger.kernel.org, Christian Brauner <brauner@kernel.org>
Subject: [PATCH v2 09/10] porting: document block device freeze and thaw changes
Date: Tue, 24 Oct 2023 15:01:15 +0200	[thread overview]
Message-ID: <20231024-vfs-super-freeze-v2-9-599c19f4faac@kernel.org> (raw)
In-Reply-To: <20231024-vfs-super-freeze-v2-0-599c19f4faac@kernel.org>

Link: https://lore.kernel.org/r/20230927-vfs-super-freeze-v1-7-ecc36d9ab4d9@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 Documentation/filesystems/porting.rst | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index d69f59700a23..78fc854c9e41 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -1052,3 +1052,15 @@ kill_anon_super(), or kill_block_super() helpers.
 
 Lock ordering has been changed so that s_umount ranks above open_mutex again.
 All places where s_umount was taken under open_mutex have been fixed up.
+
+---
+
+**recommended**
+
+Block device freezing and thawing have been moved to holder operations.
+
+Before this change, get_active_super() would only be able to find the
+superblock of the main block device, i.e., the one stored in sb->s_bdev. Block
+device freezing now works for any block device owned by a given superblock, not
+just the main block device. The get_active_super() helper is gone, so are
+bd_fsfreeze_sb, and bd_fsfreeze_mutex.

-- 
2.34.1

