Merge tag 'vfs-6.19-rc1.guards' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull superblock lock guard updates from Christian Brauner:
 "This starts the work of introducing guards for superblock related
  locks.

  Introduce super_write_guard for scoped superblock write protection.

  This provides a guard-based alternative to the manual sb_start_write()
  and sb_end_write() pattern, allowing the compiler to automatically
  handle the cleanup"

* tag 'vfs-6.19-rc1.guards' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  xfs: use super write guard in xfs_file_ioctl()
  open: use super write guard in do_ftruncate()
  btrfs: use super write guard in relocating_repair_kthread()
  ext4: use super write guard in write_mmp_block()
  btrfs: use super write guard in sb_start_write()
  btrfs: use super write guard btrfs_run_defrag_inode()
  btrfs: use super write guard in btrfs_reclaim_bgs_work()
  fs: add super_write_guard

1 files changed, 2 insertions, 6 deletions

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index ab1ff51302fb..6f57c181ff77 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -57,16 +57,12 @@ static int write_mmp_block_thawed(struct super_block *sb,
 
 static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
 {
-	int err;
-
 	/*
 	 * We protect against freezing so that we don't create dirty buffers
 	 * on frozen filesystem.
 	 */
-	sb_start_write(sb);
-	err = write_mmp_block_thawed(sb, bh);
-	sb_end_write(sb);
-	return err;
+	scoped_guard(super_write, sb)
+		return write_mmp_block_thawed(sb, bh);
 }
 
 /*