linux-kernel - [PATCH 2/2] f2fs: should put a page beyond EOF when preparing a write

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Message-Id: <20210831005346.118701-2-jaegeuk@kernel.org>
Date:   Mon, 30 Aug 2021 17:53:46 -0700
From:   Jaegeuk Kim <jaegeuk@...nel.org>
To:     linux-kernel@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net
Cc:     Jaegeuk Kim <jaegeuk@...nel.org>
Subject: [PATCH 2/2] f2fs: should put a page beyond EOF when preparing a write

The prepare_compress_overwrite() gets/locks a page to prepare a read, and calls
f2fs_read_multi_pages() which checks EOF first. If there's any page beyond EOF,
we unlock the page and set cc->rpages[i] = NULL, which we can't put the page
anymore. This makes page leak, so let's fix by putting that page.

Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
---
 fs/f2fs/data.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 8e8824605f83..41d29382eced 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2183,6 +2183,8 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
 			continue;
 		}
 		unlock_page(page);
+		if (for_write)
+			put_page(page);
 		cc->rpages[i] = NULL;
 		cc->nr_rpages--;
 	}
-- 
2.33.0.259.gc128427fd7-goog