From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 726473419D for ; Mon, 9 Oct 2023 13:52:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="086rpFwI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1AC5C433C7; Mon, 9 Oct 2023 13:52:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696859541; bh=2Lhr20GyeDSS67iGenFmOdc9m870WsyNPyo9pDI/jU0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=086rpFwIAflWbxxDQ8XXb703kdXAfQF7gI+0rkYThgQ9Y2bk6yJBsfGd2ahCsglxD aMqxXVV9Z6r9qAM17cTNt2zDDBe31DiyLPH4Qt+kPNYBIqEcdMdiVOm5aAAbVOnn4p n0M6DMAosytDGAf18YJJ3UTcpa7KzxoSpOrwV6KM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , David Sterba Subject: [PATCH 4.19 54/91] btrfs: properly report 0 avail for very full file systems Date: Mon, 9 Oct 2023 15:06:26 +0200 Message-ID: <20231009130113.390623657@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231009130111.518916887@linuxfoundation.org> References: <20231009130111.518916887@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik commit 58bfe2ccec5f9f137b41dd38f335290dcc13cd5c upstream. A user reported some issues with smaller file systems that get very full. While investigating this issue I noticed that df wasn't showing 100% full, despite having 0 chunk space and having < 1MiB of available metadata space. This turns out to be an overflow issue, we're doing: total_available_metadata_space - SZ_4M < global_block_rsv_size to determine if there's not enough space to make metadata allocations, which overflows if total_available_metadata_space is < 4M. Fix this by checking to see if our available space is greater than the 4M threshold. This makes df properly report 100% usage on the file system. CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2196,7 +2196,7 @@ static int btrfs_statfs(struct dentry *d * calculated f_bavail. */ if (!mixed && block_rsv->space_info->full && - total_free_meta - thresh < block_rsv->size) + (total_free_meta < thresh || total_free_meta - thresh < block_rsv->size)) buf->f_bavail = 0; buf->f_type = BTRFS_SUPER_MAGIC;