linux-kernel - [PATCH 2/2 linux-next] fs/affs: bugfix: Write files greater than page size on OFS

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Message-Id: <20170424201310.1796-1-fabf@skynet.be>
Date:   Mon, 24 Apr 2017 22:13:10 +0200
From:   Fabian Frederick <fabf@...net.be>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Alexander Viro <viro@...iv.linux.org.uk>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        fabf@...net.be
Subject: [PATCH 2/2 linux-next] fs/affs: bugfix: Write files greater than page size on OFS

Previous AFFS patch fixed OFS write operations but unveiled
another bug: files greater than 4KB are being created with a wrong
size resulting in errors like the following:

dd if=/dev/zero of=file bs=4097 count=1
cp file /mnt/affs/
cp: error writing '/mnt/affs/file': Bad address

Signed-off-by: Fabian Frederick <fabf@...net.be>
---
 fs/affs/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/affs/file.c b/fs/affs/file.c
index e5c5de6..196ee7f 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -679,7 +679,7 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
 	int written;
 
 	from = pos & (PAGE_SIZE - 1);
-	to = pos + len;
+	to = from + len;
 	/*
 	 * XXX: not sure if this can handle short copies (len < copied), but
 	 * we don't have to, because the page should always be uptodate here,
-- 
2.9.3