From e7266570f2cf7b3ca2a156c677ee0a59d563458b Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Mon, 2 Mar 2020 18:09:30 +0300 Subject: [PATCH] block/qcow2-threads: fix qcow2_decompress MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit On success path we return what inflate() returns instead of 0. And it most probably works for Z_STREAM_END as it is positive, but is definitely broken for Z_BUF_ERROR. While being here, switch to errno return code, to be closer to qcow2_compress API (and usual expectations). Revert condition in if to be more positive. Drop dead initialization of ret. Cc: qemu-stable@nongnu.org # v4.0 Fixes: 341926ab83e2b Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20200302150930.16218-1-vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia Reviewed-by: Ján Tomko Signed-off-by: Max Reitz --- block/qcow2-threads.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c index 77bb578cdf..a68126f291 100644 --- a/block/qcow2-threads.c +++ b/block/qcow2-threads.c @@ -128,12 +128,12 @@ static ssize_t qcow2_compress(void *dest, size_t dest_size, * @src - source buffer, @src_size bytes * * Returns: 0 on success - * -1 on fail + * -EIO on fail */ static ssize_t qcow2_decompress(void *dest, size_t dest_size, const void *src, size_t src_size) { - int ret = 0; + int ret; z_stream strm; memset(&strm, 0, sizeof(strm)); @@ -144,17 +144,19 @@ static ssize_t qcow2_decompress(void *dest, size_t dest_size, ret = inflateInit2(&strm, -12); if (ret != Z_OK) { - return -1; + return -EIO; } ret = inflate(&strm, Z_FINISH); - if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || strm.avail_out != 0) { + if ((ret == Z_STREAM_END || ret == Z_BUF_ERROR) && strm.avail_out == 0) { /* * We approve Z_BUF_ERROR because we need @dest buffer to be filled, but * @src buffer may be processed partly (because in qcow2 we know size of * compressed data with precision of one sector) */ - ret = -1; + ret = 0; + } else { + ret = -EIO; } inflateEnd(&strm); -- 2.11.0