From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 490C0C04A94 for ; Thu, 3 Aug 2023 13:58:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236272AbjHCN65 (ORCPT ); Thu, 3 Aug 2023 09:58:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234863AbjHCN64 (ORCPT ); Thu, 3 Aug 2023 09:58:56 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4A52170D; Thu, 3 Aug 2023 06:58:54 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 6661621980; Thu, 3 Aug 2023 13:58:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1691071133; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DTJxvWqtu7HdvmCpxlA8gxx5nXWxZFSZ+fc8SOhAj9s=; b=ttLo30NEZEAkZo+GKcUUBPX+disFG6lUUkR0EYZYYa8hYqnuRPq6sLr2SU4uoKfmROp5Ev EWT2MrQ44nOyQbVt1lyUN88DW9p2dyf8QbjsoL7yNMFIxSHZ9OfVNilRe+0d8yfkTwce2g s9L6Jonw9+JxUJDFDr8a3W3Ma4VRe2E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1691071133; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DTJxvWqtu7HdvmCpxlA8gxx5nXWxZFSZ+fc8SOhAj9s=; b=aowPEysjLXHqI0SvQT+3OCldkwdMtF9HPEooMKE1Q9JfGO4jSqr+/6aAQzv4N1OgExSdjN O9Ao9qJhusJ5pIDQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 5756F1333C; Thu, 3 Aug 2023 13:58:53 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id tdRSFZ2yy2RjAQAAMHmgww (envelope-from ); Thu, 03 Aug 2023 13:58:53 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id EEF92A076B; Thu, 3 Aug 2023 15:58:52 +0200 (CEST) Date: Thu, 3 Aug 2023 15:58:52 +0200 From: Jan Kara To: Baokun Li Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, ritesh.list@gmail.com, ojaswin@linux.ibm.com, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, yukuai3@huawei.com Subject: Re: [PATCH v2 3/3] ext4: avoid overlapping preallocations due to overflow Message-ID: <20230803135852.w7rfvw6veyi2abxy@quack3> References: <20230724121059.11834-1-libaokun1@huawei.com> <20230724121059.11834-4-libaokun1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230724121059.11834-4-libaokun1@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon 24-07-23 20:10:59, Baokun Li wrote: > Let's say we want to allocate 2 blocks starting from 4294966386, after > predicting the file size, start is aligned to 4294965248, len is changed > to 2048, then end = start + size = 0x100000000. Since end is of > type ext4_lblk_t, i.e. uint, end is truncated to 0. > > This causes (pa->pa_lstart >= end) to always hold when checking if the > current extent to be allocated crosses already preallocated blocks, so the > resulting ac_g_ex may cross already preallocated blocks. Hence we convert > the end type to loff_t and use pa_logical_end() to avoid overflow. > > Signed-off-by: Baokun Li Looks good to me. Feel free to add: Reviewed-by: Jan Kara Honza > --- > fs/ext4/mballoc.c | 21 ++++++++++----------- > 1 file changed, 10 insertions(+), 11 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 86bce870dc5a..78a4a24e2f57 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -4222,12 +4222,13 @@ ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_ > > static inline void > ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, > - ext4_lblk_t start, ext4_lblk_t end) > + ext4_lblk_t start, loff_t end) > { > struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); > struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); > struct ext4_prealloc_space *tmp_pa; > - ext4_lblk_t tmp_pa_start, tmp_pa_end; > + ext4_lblk_t tmp_pa_start; > + loff_t tmp_pa_end; > struct rb_node *iter; > > read_lock(&ei->i_prealloc_lock); > @@ -4236,7 +4237,7 @@ ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, > tmp_pa = rb_entry(iter, struct ext4_prealloc_space, > pa_node.inode_node); > tmp_pa_start = tmp_pa->pa_lstart; > - tmp_pa_end = tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); > + tmp_pa_end = pa_logical_end(sbi, tmp_pa); > > spin_lock(&tmp_pa->pa_lock); > if (tmp_pa->pa_deleted == 0) > @@ -4258,14 +4259,14 @@ ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, > */ > static inline void > ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, > - ext4_lblk_t *start, ext4_lblk_t *end) > + ext4_lblk_t *start, loff_t *end) > { > struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); > struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); > struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL; > struct rb_node *iter; > - ext4_lblk_t new_start, new_end; > - ext4_lblk_t tmp_pa_start, tmp_pa_end, left_pa_end = -1, right_pa_start = -1; > + ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1; > + loff_t new_end, tmp_pa_end, left_pa_end = -1; > > new_start = *start; > new_end = *end; > @@ -4284,7 +4285,7 @@ ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, > tmp_pa = rb_entry(iter, struct ext4_prealloc_space, > pa_node.inode_node); > tmp_pa_start = tmp_pa->pa_lstart; > - tmp_pa_end = tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); > + tmp_pa_end = pa_logical_end(sbi, tmp_pa); > > /* PA must not overlap original request */ > spin_lock(&tmp_pa->pa_lock); > @@ -4364,8 +4365,7 @@ ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, > } > > if (left_pa) { > - left_pa_end = > - left_pa->pa_lstart + EXT4_C2B(sbi, left_pa->pa_len); > + left_pa_end = pa_logical_end(sbi, left_pa); > BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical); > } > > @@ -4404,8 +4404,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, > struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); > struct ext4_super_block *es = sbi->s_es; > int bsbits, max; > - ext4_lblk_t end; > - loff_t size, start_off; > + loff_t size, start_off, end; > loff_t orig_size __maybe_unused; > ext4_lblk_t start; > > -- > 2.31.1 > -- Jan Kara SUSE Labs, CR