linux-kernel - [PATCH v3 6/6] gfs2: Replace kmap_atomic() by kmap_local_page() in gfs2_write_buf_to

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Date:   Fri, 30 Jun 2023 03:22:27 +0530
From:   Deepak R Varma <drv@...lo.com>
To:     Bob Peterson <rpeterso@...hat.com>,
        Andreas Gruenbacher <agruenba@...hat.com>,
        cluster-devel@...hat.com, linux-kernel@...r.kernel.org
Cc:     Ira Weiny <ira.weiny@...el.com>,
        "Fabio M. De Francesco" <fmdefrancesco@...il.com>,
        Sumitra Sharma <sumitraartsy@...il.com>,
        Deepak R Varma <drv@...lo.com>
Subject: [PATCH v3 6/6] gfs2: Replace kmap_atomic() by kmap_local_page() in
 gfs2_write_buf_to_page

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

Therefore, replace kmap_atomic() with kmap_local_page() in
gfs2_write_buf_to_page().

kmap_atomic() disables page-faults and preemption (the latter only for
!PREEMPT_RT kernels), However, the code within the mapping/un-mapping in
gfs2_write_buf_to_page() 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()).

Suggested-by: Fabio M. De Francesco <fmdefrancesco@...il.com>
Signed-off-by: Deepak R Varma <drv@...lo.com>
---
Changes in v3:
   - Patch included in patch set

Changes in v2:
   - None


 fs/gfs2/quota.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 386ca770ce2e..e5767133aeea 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -764,10 +764,10 @@ static int gfs2_write_buf_to_page(struct gfs2_inode *ip, unsigned long index,
 	}
 
 	/* Write to the page, now that we have setup the buffer(s) */
-	kaddr = kmap_atomic(page);
+	kaddr = kmap_local_page(page);
 	memcpy(kaddr + off, buf, bytes);
 	flush_dcache_page(page);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 	unlock_page(page);
 	put_page(page);
 
-- 
2.34.1