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 6F8E9C433EF for ; Thu, 28 Apr 2022 16:57:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350204AbiD1RAq (ORCPT ); Thu, 28 Apr 2022 13:00:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236416AbiD1RAn (ORCPT ); Thu, 28 Apr 2022 13:00:43 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88740B53C2; Thu, 28 Apr 2022 09:57:27 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 40096210EB; Thu, 28 Apr 2022 16:57:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1651165046; 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=sI0Q4qCHHuJeHrCT7hRK8KULGr3GzzzrmyaJAYZra3o=; b=dVA4YthPmXCw8w1ju6hpYrbycaGoL0t7OWJbQGzfBkQVH9r1zBbWoO4k+gONFqG5trQVuB 7pilT8pA+QOXX7pSlL8Ifr442npyo3Aw3oAmw7YiA0SQ2g4/4TADBx8VsQgx20vTz7C8Df cZ37SnDNLXBXfV5Sl6ouihbmb3xRp+M= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1651165046; 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=sI0Q4qCHHuJeHrCT7hRK8KULGr3GzzzrmyaJAYZra3o=; b=asFIO0NfC2COfU/Uk3pVdGJatW2YeCh67pSQ8bYbpygdOYt1mncC0WMFnJp6WY5ALpKgPx 9WIVYcyfv8ZH6yBw== Received: from quack3.suse.cz (unknown [10.100.224.230]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id DA7242C141; Thu, 28 Apr 2022 16:57:25 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id 61818A061A; Thu, 28 Apr 2022 18:57:25 +0200 (CEST) Date: Thu, 28 Apr 2022 18:57:25 +0200 From: Jan Kara To: Baokun Li Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yebin10@huawei.com, yukuai3@huawei.com, stable@vger.kernel.org, Hulk Robot Subject: Re: [PATCH v3] ext4: fix race condition between ext4_write and ext4_convert_inline_data Message-ID: <20220428165725.mvjh6mx7gr5vekqe@quack3.lan> References: <20220428134031.4153381-1-libaokun1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220428134031.4153381-1-libaokun1@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 28-04-22 21:40:31, Baokun Li wrote: > Hulk Robot reported a BUG_ON: > ================================================================== > EXT4-fs error (device loop3): ext4_mb_generate_buddy:805: group 0, > block bitmap and bg descriptor inconsistent: 25 vs 31513 free clusters > kernel BUG at fs/ext4/ext4_jbd2.c:53! > invalid opcode: 0000 [#1] SMP KASAN PTI > CPU: 0 PID: 25371 Comm: syz-executor.3 Not tainted 5.10.0+ #1 > RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:53 [inline] > RIP: 0010:__ext4_journal_stop+0x10e/0x110 fs/ext4/ext4_jbd2.c:116 > [...] > Call Trace: > ext4_write_inline_data_end+0x59a/0x730 fs/ext4/inline.c:795 > generic_perform_write+0x279/0x3c0 mm/filemap.c:3344 > ext4_buffered_write_iter+0x2e3/0x3d0 fs/ext4/file.c:270 > ext4_file_write_iter+0x30a/0x11c0 fs/ext4/file.c:520 > do_iter_readv_writev+0x339/0x3c0 fs/read_write.c:732 > do_iter_write+0x107/0x430 fs/read_write.c:861 > vfs_writev fs/read_write.c:934 [inline] > do_pwritev+0x1e5/0x380 fs/read_write.c:1031 > [...] > ================================================================== > > Above issue may happen as follows: > cpu1 cpu2 > __________________________|__________________________ > do_pwritev > vfs_writev > do_iter_write > ext4_file_write_iter > ext4_buffered_write_iter > generic_perform_write > ext4_da_write_begin > vfs_fallocate > ext4_fallocate > ext4_convert_inline_data > ext4_convert_inline_data_nolock > ext4_destroy_inline_data_nolock > clear EXT4_STATE_MAY_INLINE_DATA > ext4_map_blocks > ext4_ext_map_blocks > ext4_mb_new_blocks > ext4_mb_regular_allocator > ext4_mb_good_group_nolock > ext4_mb_init_group > ext4_mb_init_cache > ext4_mb_generate_buddy --> error > ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) > ext4_restore_inline_data > set EXT4_STATE_MAY_INLINE_DATA > ext4_block_write_begin > ext4_da_write_end > ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) > ext4_write_inline_data_end > handle=NULL > ext4_journal_stop(handle) > __ext4_journal_stop > ext4_put_nojournal(handle) > ref_cnt = (unsigned long)handle > BUG_ON(ref_cnt == 0) ---> BUG_ON > > The lock held by ext4_convert_inline_data is xattr_sem, but the lock > held by generic_perform_write is i_rwsem. Therefore, the two locks can > be concurrent. > > To solve above issue, we add inode_lock() for ext4_convert_inline_data(). > At the same time, move ext4_convert_inline_data() in front of > ext4_punch_hole(), remove similar handling from ext4_punch_hole(). > > Fixes: 0c8d414f163f ("ext4: let fallocate handle inline data correctly") > Cc: stable@vger.kernel.org > Reported-by: Hulk Robot > Signed-off-by: Baokun Li Looks good to me. Feel free to add: Reviewed-by: Jan Kara Honza > --- > V1->V2: > Increase the range of the inode_lock. > V2->V3: > Move the lock outside the ext4_convert_inline_data(). > And reorganize ext4_fallocate(). > > fs/ext4/extents.c | 10 ++++++---- > fs/ext4/inode.c | 9 --------- > 2 files changed, 6 insertions(+), 13 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index e473fde6b64b..474479ce76e0 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -4693,15 +4693,17 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) > FALLOC_FL_INSERT_RANGE)) > return -EOPNOTSUPP; > > + inode_lock(inode); > + ret = ext4_convert_inline_data(inode); > + inode_unlock(inode); > + if (ret) > + goto exit; > + > if (mode & FALLOC_FL_PUNCH_HOLE) { > ret = ext4_punch_hole(file, offset, len); > goto exit; > } > > - ret = ext4_convert_inline_data(inode); > - if (ret) > - goto exit; > - > if (mode & FALLOC_FL_COLLAPSE_RANGE) { > ret = ext4_collapse_range(file, offset, len); > goto exit; > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 646ece9b3455..4779673d733e 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3967,15 +3967,6 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) > > trace_ext4_punch_hole(inode, offset, length, 0); > > - ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); > - if (ext4_has_inline_data(inode)) { > - filemap_invalidate_lock(mapping); > - ret = ext4_convert_inline_data(inode); > - filemap_invalidate_unlock(mapping); > - if (ret) > - return ret; > - } > - > /* > * Write out all dirty pages to avoid race conditions > * Then release them. > -- > 2.31.1 > -- Jan Kara SUSE Labs, CR