linux-kernel - [PATCH] fs: ntfs3: remove redundant kmap() calls

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Message-ID: <20251104161913.20256-1-i.shihao.999@gmail.com>
Date: Tue,  4 Nov 2025 21:49:13 +0530
From: Shi Hao <i.shihao.999@...il.com>
To: almaz.alexandrovich@...agon-software.com
Cc: ntfs3@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	i.shihao.999@...il.com
Subject: [PATCH] fs: ntfs3: remove redundant kmap() calls

Remove unnecessary kmap() mapping calls which serve
no functional purpose because their return values are
immediately discarded right after the calls and also
vmap() calls has been used right after these kmap()
functions which is another contiguous memory mapping
function too.

Signed-off-by: Shi Hao <i.shihao.999@...il.com>
---
 fs/ntfs3/frecord.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 8f9fe1d7a690..372673bf803f 100644
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -2407,8 +2407,6 @@ int ni_read_frame(struct ntfs_inode *ni, u64 frame_vbo, struct page **pages,
 	 * To simplify decompress algorithm do vmap for source
 	 * and target pages.
 	 */
-	for (i = 0; i < pages_per_frame; i++)
-		kmap(pages[i]);

 	frame_size = pages_per_frame << PAGE_SHIFT;
 	frame_mem = vmap(pages, pages_per_frame, VM_MAP, PAGE_KERNEL);
@@ -2657,7 +2655,6 @@ int ni_read_frame(struct ntfs_inode *ni, u64 frame_vbo, struct page **pages,
 out:
 	for (i = 0; i < pages_per_frame; i++) {
 		pg = pages[i];
-		kunmap(pg);
 		SetPageUptodate(pg);
 	}

@@ -2735,7 +2732,6 @@ int ni_write_frame(struct ntfs_inode *ni, struct page **pages,
 		}
 		pages_disk[i] = pg;
 		lock_page(pg);
-		kmap(pg);
 	}

 	/* To simplify compress algorithm do vmap for source and target pages. */
@@ -2745,9 +2741,6 @@ int ni_write_frame(struct ntfs_inode *ni, struct page **pages,
 		goto out1;
 	}

-	for (i = 0; i < pages_per_frame; i++)
-		kmap(pages[i]);
-
 	/* Map in-memory frame for read-only. */
 	frame_mem = vmap(pages, pages_per_frame, VM_MAP, PAGE_KERNEL_RO);
 	if (!frame_mem) {
@@ -2815,15 +2808,11 @@ int ni_write_frame(struct ntfs_inode *ni, struct page **pages,
 	vunmap(frame_mem);

 out2:
-	for (i = 0; i < pages_per_frame; i++)
-		kunmap(pages[i]);
-
 	vunmap(frame_ondisk);
 out1:
 	for (i = 0; i < pages_per_frame; i++) {
 		pg = pages_disk[i];
 		if (pg) {
-			kunmap(pg);
 			unlock_page(pg);
 			put_page(pg);
 		}
--
2.51.0