+ filemap-fix-the-last_index-of-mm_filemap_get_pages.patch added to mm-unstable branch

+ filemap-fix-the-last_index-of-mm_filemap_get_pages.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: filemap: fix the last_index of mm_filemap_get_pages
has been added to the -mm mm-unstable branch.  Its filename is
     filemap-fix-the-last_index-of-mm_filemap_get_pages.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/filemap-fix-the-last_index-of-mm_filemap_get_pages.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Takaya Saeki <takayas@chromium.org>
Subject: filemap: fix the last_index of mm_filemap_get_pages
Date: Tue, 3 Sep 2024 10:21:00 +0000

In commit b6273b55d885 ("filemap: add trace events for get_pages,
map_pages, and fault"), mm_filemap_get_pages was added to trace page cache
access.  However, it tracks an extra page beyond the end of the accessed
range.  This patch fixes it by replacing last_index with last_index - 1.

Link: https://lkml.kernel.org/r/20240903102100.70405-1-takayas@chromium.org
Fixes: b6273b55d885 ("filemap: add trace events for get_pages, map_pages, and fault")
Signed-off-by: Takaya Saeki <takayas@chromium.org>
Cc: Junichi Uekawa <uekawa@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/filemap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/filemap.c~filemap-fix-the-last_index-of-mm_filemap_get_pages
+++ a/mm/filemap.c
@@ -2571,7 +2571,7 @@ retry:
 			goto err;
 	}
 
-	trace_mm_filemap_get_pages(mapping, index, last_index);
+	trace_mm_filemap_get_pages(mapping, index, last_index - 1);
 	return 0;
 err:
 	if (err < 0)
_

Patches currently in -mm which might be from takayas@chromium.org are

filemap-fix-the-last_index-of-mm_filemap_get_pages.patch