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Thu, 4 Jan 2024 10:43:32 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id tT8oB9SLlmXCdgAAD6G6ig (envelope-from ); Thu, 04 Jan 2024 10:43:32 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id D9C98A07EF; Thu, 4 Jan 2024 11:43:31 +0100 (CET) Date: Thu, 4 Jan 2024 11:43:31 +0100 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, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, yukuai3@huawei.com Subject: Re: [PATCH v2 5/8] ext4: avoid dividing by 0 in mb_update_avg_fragment_size() when block bitmap corrupt Message-ID: <20240104104331.udagyt3wv4xfchgq@quack3> References: <20231221150558.2740823-1-libaokun1@huawei.com> <20231221150558.2740823-6-libaokun1@huawei.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231221150558.2740823-6-libaokun1@huawei.com> X-Spam-Score: 1.90 X-Spamd-Result: default: False [1.90 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; BAYES_HAM(-0.00)[35.80%]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; RCPT_COUNT_SEVEN(0.00)[10]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email,suse.cz:email]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; MID_RHS_NOT_FQDN(0.50)[]; FREEMAIL_CC(0.00)[vger.kernel.org,mit.edu,dilger.ca,suse.cz,gmail.com,huawei.com]; RCVD_TLS_ALL(0.00)[]; SUSPICIOUS_RECIPS(1.50)[] Authentication-Results: smtp-out2.suse.de; none X-Spam-Level: * X-Spam-Flag: NO On Thu 21-12-23 23:05:55, Baokun Li wrote: > Determine if bb_fragments is 0 instead of determining bb_free to eliminate > the risk of dividing by zero when the block bitmap is corrupted. > > Signed-off-by: Baokun Li Looks good. Feel free to add: Reviewed-by: Jan Kara Honza > --- > fs/ext4/mballoc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 1f15774971d7..03500aec43ac 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -842,7 +842,7 @@ mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp) > struct ext4_sb_info *sbi = EXT4_SB(sb); > int new_order; > > - if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0) > + if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0) > return; > > new_order = mb_avg_fragment_size_order(sb, > -- > 2.31.1 > -- Jan Kara SUSE Labs, CR