[PATCH 1/4] fs/sysv: Use the offset_in_page() helper

From: Fabio M. De Francesco
Date: Sat Dec 31 2022 - 02:57:38 EST


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>
Suggested-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
---
fs/sysv/dir.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index 88e38cd8f5c9..685379bc9d64 100644
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -206,8 +206,7 @@ int sysv_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);
lock_page(page);
err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
if (err)
@@ -230,8 +229,7 @@ int sysv_add_link(struct dentry *dentry, struct inode *inode)
int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
{
struct inode *inode = page->mapping->host;
- char *kaddr = (char*)page_address(page);
- loff_t pos = page_offset(page) + (char *)de - kaddr;
+ loff_t pos = page_offset(page) + offset_in_page(de);
int err;

lock_page(page);
@@ -328,8 +326,7 @@ void sysv_set_link(struct sysv_dir_entry *de, struct page *page,
struct inode *inode)
{
struct inode *dir = page->mapping->host;
- loff_t pos = page_offset(page) +
- (char *)de-(char*)page_address(page);
+ loff_t pos = page_offset(page) + offset_in_page(de);
int err;

lock_page(page);
--
2.39.0