From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f68.google.com ([209.85.215.68]:36341 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750940AbdETSkz (ORCPT ); Sat, 20 May 2017 14:40:55 -0400 Received: by mail-lf0-f68.google.com with SMTP id h4so2283293lfj.3 for ; Sat, 20 May 2017 11:40:54 -0700 (PDT) From: Timofey Titovets To: linux-btrfs@vger.kernel.org Cc: Timofey Titovets Subject: [PATCH v3 2/2] Btrfs: compression must free at least PAGE_SIZE Date: Sat, 20 May 2017 21:40:39 +0300 Message-Id: <20170520184039.31362-3-nefelim4ag@gmail.com> In-Reply-To: <20170520184039.31362-1-nefelim4ag@gmail.com> References: <20170520184039.31362-1-nefelim4ag@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Btrfs already skip store of data where compression didn't free at least one byte. So make logic better and make check that compression free at least one PAGE_SIZE, because in another case it useless to store this data compressed Signed-off-by: Timofey Titovets --- fs/btrfs/lzo.c | 5 ++++- fs/btrfs/zlib.c | 3 ++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index bd0b0938..39678499 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -229,8 +229,11 @@ static int lzo_compress_pages(struct list_head *ws, in_len = min(bytes_left, PAGE_SIZE); } - if (tot_out > tot_in) + /* Compression must save at least one PAGE_SIZE */ + if (tot_out + PAGE_SIZE > tot_in) { + ret = -E2BIG; goto out; + } /* store the size of all chunks of compressed data */ cpage_out = kmap(pages[0]); diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 135b1082..11e117b5 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -191,7 +191,8 @@ static int zlib_compress_pages(struct list_head *ws, goto out; } - if (workspace->strm.total_out >= workspace->strm.total_in) { + /* Compression must save at least one PAGE_SIZE */ + if (workspace->strm.total_out + PAGE_SIZE > workspace->strm.total_in) { ret = -E2BIG; goto out; } -- 2.13.0