Re: [PATCH v8 06/19] block, fs: Propagate write hints to the block device inode

Christoph Hellwig
2023-12-28T07:12:10Z

On Mon, Dec 18, 2023 at 04:07:39PM -0800, Bart Van Assche wrote:
> Write hints applied with F_SET_RW_HINT on a block device affect the
> shmem inode only. Propagate these hints to the block device inode
> because that is the inode used when writing back dirty pages.

What shmem inode?

> @@ -317,6 +318,9 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
>
> inode_lock(inode);
> inode->i_write_hint = hint;
> + apply_whint = inode->i_fop->apply_whint;
> + if (apply_whint)
> + apply_whint(file, hint);

Setting the hint in file->f_mapping->inode is the right thing here,
not adding a method.