From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Chao Yu <yuchao0@huawei.com>,
        Gao Xiang <gaoxiang25@huawei.com>
Subject: [PATCH 4.19 134/152] staging: erofs: fix a bug when appling cache strategy
Date:   Mon, 25 Feb 2019 22:12:06 +0100
Message-Id: <20190225195052.880349334@linuxfoundation.org>
In-Reply-To: <20190225195043.645958524@linuxfoundation.org>
References: <20190225195043.645958524@linuxfoundation.org>
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4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gao Xiang <gaoxiang25@huawei.com>

commit 0734ffbf574ee813b20899caef2fe0ed502bb783 upstream.

As described in Kconfig, the last compressed pack should be cached
for further reading for either `EROFS_FS_ZIP_CACHE_UNIPOLAR' or
`EROFS_FS_ZIP_CACHE_BIPOLAR' by design.

However, there is a bug in z_erofs_do_read_page, it will
switch `initial' to `false' at the very beginning before it decides
to cache the last compressed pack.

caching strategy should work properly after appling this patch.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/staging/erofs/unzip_vle.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -624,7 +624,7 @@ repeat:
 	/* go ahead the next map_blocks */
 	debugln("%s: [out-of-range] pos %llu", __func__, offset + cur);
 
-	if (!z_erofs_vle_work_iter_end(builder))
+	if (z_erofs_vle_work_iter_end(builder))
 		fe->initial = false;
 
 	map->m_la = offset + cur;