Commit 2142b88c authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Christian Brauner
Browse files

block: call into the file system for ioctl BLKFLSBUF 



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: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Message-Id: <20230811100828.1897174-16-hch@lst.de>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent d8530de5

block/bdev.c

+0 −16
Original line number Diff line number Diff line
@@ -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

block/ioctl.c

+8 −1
Original line number Diff line number Diff line
@@ -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;

}

fs/super.c

+13 −0
Original line number Diff line number Diff line
@@ -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);

}



const struct blk_holder_ops fs_holder_ops = {

	.mark_dead		= fs_bdev_mark_dead,

	.sync			= fs_bdev_sync,

};

EXPORT_SYMBOL_GPL(fs_holder_ops);

include/linux/blkdev.h

+5 −2
Original line number Diff line number Diff line
@@ -1462,6 +1462,11 @@ void blkdev_show(struct seq_file *seqf, off_t offset); 


struct blk_holder_ops {

	void (*mark_dead)(struct block_device *bdev, bool surprise);



	/*

	 * Sync the file system mounted on the block device.

	 */

	void (*sync)(struct block_device *bdev);

};



extern const struct blk_holder_ops fs_holder_ops;
@@ -1524,8 +1529,6 @@ static inline int early_lookup_bdev(const char *pathname, dev_t *dev) 
}

#endif /* CONFIG_BLOCK */



int fsync_bdev(struct block_device *bdev);



int freeze_bdev(struct block_device *bdev);

int thaw_bdev(struct block_device *bdev);