[PATCH v2] gfs2: Replace deprecated kmap_atomic() by kmap_local_page()

From: Deepak R Varma
Date: Mon Jun 26 2023 - 02:51:32 EST


kmap_atomic() is deprecated in favor of kmap_local_{folio,page}().

Therefore, replace kmap_atomic() with kmap_local_page() in
gfs2_internal_read() and stuffed_readpage().

kmap_atomic() disables page-faults and preemption (the latter only for
!PREEMPT_RT kernels), However, the code within the mapping/un-mapping in
gfs2_internal_read() and stuffed_readpage() does not depend on the
above-mentioned side effects.

Therefore, a mere replacement of the old API with the new one is all that
is required (i.e., there is no need to explicitly add any calls to
pagefault_disable() and/or preempt_disable()).

Signed-off-by: Deepak R Varma <drv@xxxxxxxxx>
---
Note: The Patch is build tested only. I will be happy to run recommended testing
with some guidance if required.

Changes in v2:
- Update patch description to correct the replacement function name from
kmap_local_folio to kmap_local _page


fs/gfs2/aops.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 3b41542d6697..7bd92054d353 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -432,10 +432,10 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
if (error)
return error;

- kaddr = kmap_atomic(page);
+ kaddr = kmap_local_page(page);
memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
- kunmap_atomic(kaddr);
+ kunmap_local(kaddr);
flush_dcache_page(page);
brelse(dibh);
SetPageUptodate(page);
@@ -498,12 +498,12 @@ int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
continue;
return PTR_ERR(page);
}
- p = kmap_atomic(page);
+ p = kmap_local_page(page);
amt = size - copied;
if (offset + size > PAGE_SIZE)
amt = PAGE_SIZE - offset;
memcpy(buf + copied, p + offset, amt);
- kunmap_atomic(p);
+ kunmap_local(p);
put_page(page);
copied += amt;
index++;
--
2.34.1