On Thu, Dec 29, 2022 at 11:50:57PM +0100, Fabio M. De Francesco wrote:
> Use the offset_in_page() helper because it is more suitable than doing
> explicit subtractions between pointers to directory entries and kernel
> virtual addresses of mapped pages.
>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> Suggested-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
> ---
> fs/ufs/dir.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
> index 391efaf1d528..69f78583c9c1 100644
> --- a/fs/ufs/dir.c
> +++ b/fs/ufs/dir.c
> @@ -87,8 +87,7 @@ void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
> struct page *page, struct inode *inode,
> bool update_times)
> {
> - loff_t pos = page_offset(page) +
> - (char *) de - (char *) page_address(page);
> + loff_t pos = page_offset(page) + offset_in_page(de);
> unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
> int err;
>
> @@ -371,8 +370,7 @@ int ufs_add_link(struct dentry *dentry, struct inode *inode)
> return -EINVAL;
>
> got_it:
> - pos = page_offset(page) +
> - (char*)de - (char*)page_address(page);
> + pos = page_offset(page) + offset_in_page(de);
> err = ufs_prepare_chunk(page, pos, rec_len);
> if (err)
> goto out_unlock;
> @@ -497,8 +495,8 @@ int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
> {
> struct super_block *sb = inode->i_sb;
> char *kaddr = page_address(page);
> - unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
> - unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
> + unsigned int from = offset_in_page(dir) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
> + unsigned int to = offset_in_page(dir) + fs16_to_cpu(sb, dir->d_reclen);
> loff_t pos;
> struct ufs_dir_entry *pde = NULL;
> struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
> @@ -522,7 +520,7 @@ int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
> de = ufs_next_entry(sb, de);
> }
> if (pde)
> - from = (char*)pde - (char*)page_address(page);
> + from = offset_in_page(pde);
>
> pos = page_offset(page) + from;
> lock_page(page);
> --
> 2.39.0
>
