linux-kernel - [PATCH v3 1/6] gfs2: Replace kmap_atomic() by kmap_local_page() in stuffed

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Message-ID: <1955d9c440240f4c97efd80f3efca550871fe0ef.1688073459.git.drv@mailo.com>
Date:   Fri, 30 Jun 2023 03:19:29 +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 1/6] gfs2: Replace kmap_atomic() by kmap_local_page() in
 stuffed_readpage

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

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

Suggested-by: Fabio M. De Francesco <fmdefrancesco@...il.com>
Signed-off-by: Deepak R Varma <drv@...lo.com>
---
Changes in v3:
   - split into 2 patches
   - included in the patch set. Was sent as standalone patch previously

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


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

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 3b41542d6697..3eac4f2f5c27 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);
-- 
2.34.1