Re: [PATCH 4/5] block: introduce file_bd_inode()

[Jan Kara <jack@suse.cz>]

On Thu 22-10-15 02:42:05, Dan Williams wrote:
> Similar to the file_inode() helper, provide a helper to lookup the inode for a
> raw block device itself.

So I somewhat dislike the name file_bd_inode() since for struct file
pointing to a regular file, the result would be equivalent to file_inode()
but the name suggests (at least to me) it should return block device inode.
I'd name it like bdev_file_inode() to make it clear this is local to
block device code...

								Honza

> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  fs/block_dev.c |   19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 0a793c7930eb..3255dcec96b4 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -147,11 +147,16 @@ blkdev_get_block(struct inode *inode, sector_t iblock,
>  	return 0;
>  }
>  
> +static struct inode *file_bd_inode(struct file *file)
> +{
> +	return file->f_mapping->host;
> +}
> +
>  static ssize_t
>  blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
>  {
>  	struct file *file = iocb->ki_filp;
> -	struct inode *inode = file->f_mapping->host;
> +	struct inode *inode = file_bd_inode(file);
>  
>  	if (IS_DAX(inode))
>  		return dax_do_io(iocb, inode, iter, offset, blkdev_get_block,
> @@ -329,7 +334,7 @@ static int blkdev_write_end(struct file *file, struct address_space *mapping,
>   */
>  static loff_t block_llseek(struct file *file, loff_t offset, int whence)
>  {
> -	struct inode *bd_inode = file->f_mapping->host;
> +	struct inode *bd_inode = file_bd_inode(file);
>  	loff_t retval;
>  
>  	mutex_lock(&bd_inode->i_mutex);
> @@ -340,7 +345,7 @@ static loff_t block_llseek(struct file *file, loff_t offset, int whence)
>  	
>  int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
>  {
> -	struct inode *bd_inode = filp->f_mapping->host;
> +	struct inode *bd_inode = file_bd_inode(filp);
>  	struct block_device *bdev = I_BDEV(bd_inode);
>  	int error;
>  	
> @@ -1579,14 +1584,14 @@ EXPORT_SYMBOL(blkdev_put);
>  
>  static int blkdev_close(struct inode * inode, struct file * filp)
>  {
> -	struct block_device *bdev = I_BDEV(filp->f_mapping->host);
> +	struct block_device *bdev = I_BDEV(file_bd_inode(filp));
>  	blkdev_put(bdev, filp->f_mode);
>  	return 0;
>  }
>  
>  static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
>  {
> -	struct block_device *bdev = I_BDEV(file->f_mapping->host);
> +	struct block_device *bdev = I_BDEV(file_bd_inode(file));
>  	fmode_t mode = file->f_mode;
>  
>  	/*
> @@ -1611,7 +1616,7 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
>  ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  {
>  	struct file *file = iocb->ki_filp;
> -	struct inode *bd_inode = file->f_mapping->host;
> +	struct inode *bd_inode = file_bd_inode(file);
>  	loff_t size = i_size_read(bd_inode);
>  	struct blk_plug plug;
>  	ssize_t ret;
> @@ -1643,7 +1648,7 @@ EXPORT_SYMBOL_GPL(blkdev_write_iter);
>  ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  {
>  	struct file *file = iocb->ki_filp;
> -	struct inode *bd_inode = file->f_mapping->host;
> +	struct inode *bd_inode = file_bd_inode(file);
>  	loff_t size = i_size_read(bd_inode);
>  	loff_t pos = iocb->ki_pos;
>  
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR