On Fri, Aug 11, 2023 at 12:08:26PM +0200, Christoph Hellwig wrote:
> BLKFLSBUF is a historic ioctl that is called on a file handle to a
> block device and syncs either the file system mounted on that block
> device if there is one, or otherwise the just the data on the block
> device.
>
> Replace the get_super based syncing with a holder operation to remove
> the last usage of get_super, and to also support syncing the file system
> if the block device is not the main block device stored in s_dev.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> block/bdev.c | 16 ----------------
> block/ioctl.c | 9 ++++++++-
> fs/super.c | 13 +++++++++++++
> include/linux/blkdev.h | 7 +++++--
> 4 files changed, 26 insertions(+), 19 deletions(-)
>
> diff --git a/block/bdev.c b/block/bdev.c
> index 658d5dd62cac0a..2a035be7f3ee90 100644
> --- a/block/bdev.c
> +++ b/block/bdev.c
> @@ -206,22 +206,6 @@ int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend)
> }
> EXPORT_SYMBOL(sync_blockdev_range);
>
> -/*
> - * Write out and wait upon all dirty data associated with this
> - * device. Filesystem data as well as the underlying block
> - * device. Takes the superblock lock.
> - */
> -int fsync_bdev(struct block_device *bdev)
> -{
> - struct super_block *sb = get_super(bdev);
> - if (sb) {
> - int res = sync_filesystem(sb);
> - drop_super(sb);
> - return res;
> - }
> - return sync_blockdev(bdev);
> -}
> -
> /**
> * freeze_bdev - lock a filesystem and force it into a consistent state
> * @bdev: blockdevice to lock
> diff --git a/block/ioctl.c b/block/ioctl.c
> index 3be11941fb2ddc..648670ddb164a0 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -364,7 +364,14 @@ static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd,
> {
> if (!capable(CAP_SYS_ADMIN))
> return -EACCES;
> - fsync_bdev(bdev);
> +
> + mutex_lock(&bdev->bd_holder_lock);
> + if (bdev->bd_holder_ops && bdev->bd_holder_ops->sync)
> + bdev->bd_holder_ops->sync(bdev);
> + else
> + sync_blockdev(bdev);
> + mutex_unlock(&bdev->bd_holder_lock);
> +
> invalidate_bdev(bdev);
> return 0;
> }
> diff --git a/fs/super.c b/fs/super.c
> index 94d41040584f7b..714dbae58b5e8e 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -1248,8 +1248,21 @@ static void fs_bdev_mark_dead(struct block_device *bdev, bool surprise)
> up_read(&sb->s_umount);
> }
>
> +static void fs_bdev_sync(struct block_device *bdev)
> +{
> + struct super_block *sb = bdev->bd_holder;
> +
> + lockdep_assert_held(&bdev->bd_holder_lock);
> +
> + if (!lock_active_super(sb))
> + return;
> + sync_filesystem(sb);
> + up_read(&sb->s_umount);
> +}
> +
Whitespace error. Thanks,
Josef
