linux-ext4 - [PATCH 10/13] ext4: clear BH_Uptodate flag on decryption error

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Message-Id: <20190501224515.43059-11-ebiggers@kernel.org>
Date:   Wed,  1 May 2019 15:45:12 -0700
From:   Eric Biggers <ebiggers@...nel.org>
To:     linux-fscrypt@...r.kernel.org
Cc:     linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
        linux-mtd@...ts.infradead.org, linux-fsdevel@...r.kernel.org,
        Chandan Rajendra <chandan@...ux.ibm.com>
Subject: [PATCH 10/13] ext4: clear BH_Uptodate flag on decryption error

From: Chandan Rajendra <chandan@...ux.ibm.com>

If decryption fails, ext4_block_write_begin() can return with the page's
buffer_head marked with the BH_Uptodate flag.  This commit clears the
BH_Uptodate flag in such cases.

Signed-off-by: Chandan Rajendra <chandan@...ux.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@...gle.com>
---
 fs/ext4/inode.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1ef5d791834fc..9382e1bcefe49 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1225,10 +1225,14 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 		if (!buffer_uptodate(*wait_bh))
 			err = -EIO;
 	}
-	if (unlikely(err))
+	if (unlikely(err)) {
 		page_zero_new_buffers(page, from, to);
-	else if (decrypt)
+	} else if (decrypt) {
 		err = fscrypt_decrypt_pagecache_blocks(page, PAGE_SIZE, 0);
+		if (err)
+			clear_buffer_uptodate(*wait_bh);
+	}
+
 	return err;
 }
 #endif
-- 
2.21.0.593.g511ec345e18-goog