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 9808B1F37D4; Fri, 31 Oct 2025 14:04:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761919465; cv=none; b=h8MuoGE/Hu7NtPguvbgxHMVzY2OBkEpxMzslL3HHeE6Fkb7m+HlPcxaKZFitz5vM9hC9DRbxVFXnyJacd7IkggGGv8YwThA5xGnt6OxYSswiVu5Qs9QqhVUw9fVh4QkqcD2wmZU2avMrFSch2fXv9Ty6jizgIuBTvD2Gag4pQa0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761919465; c=relaxed/simple; bh=JVVhTdpAh1ERePxvoVFY9srX0SICzNclRQsLb7Pi+DU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TN5yyUUQS6S2GiQPwSh1y77krM86G+TvfM/wztDo1Uj9/w3u1cigGdgTDOcAVD3ejzZBABju2OZHUg78TioFBSty0QpcvXJzg0h15MSQZdBjnX7kZ0yq5DmRBApoGd+fYO66BApfoSCWkU54YhNzLzMBzzhe+JYSmtkE3xFnL7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=c1+Ju9CM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="c1+Ju9CM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20965C4CEE7; Fri, 31 Oct 2025 14:04:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761919465; bh=JVVhTdpAh1ERePxvoVFY9srX0SICzNclRQsLb7Pi+DU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c1+Ju9CMGPtYt+uXHKTjlI6+U6BhMqpmw4CJ0/3+bts3GZe//lcxRgk8f2xuuCGbk kIIX8BOdDc6CSEDTksmeZGvD9iGIFVNiUH+obvXcJtqNU76F33GtvEd5/wVkBHOehl DUYMt/xPbVINQqbUkZxvLFr3ZY6nU9St/bA+yRr4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+15669ec8c35ddf6c3d43@syzkaller.appspotmail.com, Chao Yu , Jaegeuk Kim , Rajani Kantha <681739313@139.com> Subject: [PATCH 6.12 28/40] f2fs: fix to avoid panic once fallocation fails for pinfile Date: Fri, 31 Oct 2025 15:01:21 +0100 Message-ID: <20251031140044.700899778@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251031140043.939381518@linuxfoundation.org> References: <20251031140043.939381518@linuxfoundation.org> User-Agent: quilt/0.69 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chao Yu [ Upstream commit 48ea8b200414ac69ea96f4c231f5c7ef1fbeffef ] syzbot reports a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2746! CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0 RIP: 0010:get_new_segment fs/f2fs/segment.c:2746 [inline] RIP: 0010:new_curseg+0x1f52/0x1f70 fs/f2fs/segment.c:2876 Call Trace: __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3210 f2fs_allocate_new_section fs/f2fs/segment.c:3224 [inline] f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3238 f2fs_expand_inode_data+0x696/0xca0 fs/f2fs/file.c:1830 f2fs_fallocate+0x537/0xa10 fs/f2fs/file.c:1940 vfs_fallocate+0x569/0x6e0 fs/open.c:327 do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x80/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Concurrent pinfile allocation may run out of free section, result in panic in get_new_segment(), let's expand pin_sem lock coverage to include f2fs_gc(), so that we can make sure to reclaim enough free space for following allocation. In addition, do below changes to enhance error path handling: - call f2fs_bug_on() only in non-pinfile allocation path in get_new_segment(). - call reset_curseg_fields() to reset all fields of curseg in new_curseg() Fixes: f5a53edcf01e ("f2fs: support aligned pinned file") Reported-by: syzbot+15669ec8c35ddf6c3d43@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/675cd64e.050a0220.37aaf.00bb.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Rajani Kantha <681739313@139.com> Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/file.c | 8 +++++--- fs/f2fs/segment.c | 20 ++++++++++---------- 2 files changed, 15 insertions(+), 13 deletions(-) --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1836,18 +1836,20 @@ static int f2fs_expand_inode_data(struct map.m_len = sec_blks; next_alloc: + f2fs_down_write(&sbi->pin_sem); + if (has_not_enough_free_secs(sbi, 0, f2fs_sb_has_blkzoned(sbi) ? ZONED_PIN_SEC_REQUIRED_COUNT : GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) { f2fs_down_write(&sbi->gc_lock); stat_inc_gc_call_count(sbi, FOREGROUND); err = f2fs_gc(sbi, &gc_control); - if (err && err != -ENODATA) + if (err && err != -ENODATA) { + f2fs_up_write(&sbi->pin_sem); goto out_err; + } } - f2fs_down_write(&sbi->pin_sem); - err = f2fs_allocate_pinning_section(sbi); if (err) { f2fs_up_write(&sbi->pin_sem); --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -2749,7 +2749,7 @@ find_other_zone: MAIN_SECS(sbi)); if (secno >= MAIN_SECS(sbi)) { ret = -ENOSPC; - f2fs_bug_on(sbi, 1); + f2fs_bug_on(sbi, !pinning); goto out_unlock; } } @@ -2795,7 +2795,7 @@ got_it: out_unlock: spin_unlock(&free_i->segmap_lock); - if (ret == -ENOSPC) + if (ret == -ENOSPC && !pinning) f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT); return ret; } @@ -2868,6 +2868,13 @@ static unsigned int __get_next_segno(str return curseg->segno; } +static void reset_curseg_fields(struct curseg_info *curseg) +{ + curseg->inited = false; + curseg->segno = NULL_SEGNO; + curseg->next_segno = 0; +} + /* * Allocate a current working segment. * This function always allocates a free segment in LFS manner. @@ -2886,7 +2893,7 @@ static int new_curseg(struct f2fs_sb_inf ret = get_new_segment(sbi, &segno, new_sec, pinning); if (ret) { if (ret == -ENOSPC) - curseg->segno = NULL_SEGNO; + reset_curseg_fields(curseg); return ret; } @@ -3640,13 +3647,6 @@ static void f2fs_randomize_chunk(struct get_random_u32_inclusive(1, sbi->max_fragment_hole); } -static void reset_curseg_fields(struct curseg_info *curseg) -{ - curseg->inited = false; - curseg->segno = NULL_SEGNO; - curseg->next_segno = 0; -} - int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, block_t old_blkaddr, block_t *new_blkaddr, struct f2fs_summary *sum, int type,