WARNING in __writeback_inodes_sb

WARNING in __writeback_inodes_sb_nr
Status: upstream: reported C repro on 2020/09/20 14:27
Reported-by: syzbot+5c2dc141988585eb49ce@syzkaller.appspotmail.com
First crash: 442d, last: 74d

Fix bisection: failed (bisect log)

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	WARNING in __writeback_inodes_sb_nr	syz	done	error	2	364d	418d	0/22	upstream: reported syz repro on 2020/10/14 12:01

Sample crash report:

BTRFS: device fsid f90cac8b-044b-4fa8-8bee-4b8d3da88dc2 devid 1 transid 7 /dev/loop0
BTRFS info (device loop0): turning on flush-on-commit
BTRFS info (device loop0): disk space caching is enabled
BTRFS info (device loop0): has skinny extents
------------[ cut here ]------------
WARNING: CPU: 1 PID: 8151 at fs/fs-writeback.c:2390 __writeback_inodes_sb_nr.cold+0x11/0x18 fs/fs-writeback.c:2390
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 8151 Comm: btrfs-transacti Not tainted 4.19.190-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x5a kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:__writeback_inodes_sb_nr.cold+0x11/0x18 fs/fs-writeback.c:2390
Code: bb e8 5d e2 6e f9 48 c7 c7 e0 f3 74 88 e8 76 ea fe ff 0f 0b e9 ac 33 ba f9 e8 45 e2 6e f9 48 c7 c7 e0 f3 74 88 e8 5e ea fe ff <0f> 0b e9 00 56 ba f9 e8 2d e2 6e f9 48 c7 c7 e0 f3 74 88 e8 46 ea
RSP: 0018:ffff88808bd5fc48 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 1ffff110117abf8b RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814dde61 RDI: ffffed10117abf7b
RBP: ffff8880b257c680 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000006400
R13: ffff8880952b2bc0 R14: ffff8880b257c7b0 R15: ffff88808bd5fc88
 btrfs_start_delalloc_flush fs/btrfs/transaction.c:1925 [inline]
 btrfs_commit_transaction+0x1bb1/0x2480 fs/btrfs/transaction.c:2076
 transaction_kthread+0x385/0x490 fs/btrfs/disk-io.c:1794
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (32):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-linux-4-19	2021/05/15 05:43	linux-4.19.y	3c8c23092588	8bdd5343	.config	log	report	syz	C		WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/04/05 11:26	linux-4.19.y	2034d6f0838e	6a81331a	.config	log	report	syz	C		WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2020/10/02 11:10	linux-4.19.y	b09c34517e1a	9602ddf4	.config	log	report	syz	C
ci2-linux-4-19	2020/09/20 17:13	linux-4.19.y	015e94d0e37b	9564d2e9	.config	log	report	syz	C
ci2-linux-4-19	2021/06/25 05:33	linux-4.19.y	eb575cd5d7f6	0edbbe31	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/06/15 18:16	linux-4.19.y	9a2dc0e6c531	8022d7e3	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/05/16 14:09	linux-4.19.y	3c8c23092588	f54a5c09	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/05/12 00:16	linux-4.19.y	3c8c23092588	b3c3bb8e	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/04/20 16:15	linux-4.19.y	2965db2e004c	c0ced557	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/04/05 04:05	linux-4.19.y	2034d6f0838e	6a81331a	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/04/02 14:15	linux-4.19.y	2034d6f0838e	6a81331a	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/03/25 21:24	linux-4.19.y	78fec1611cbf	6a383ecf	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/02/12 00:21	linux-4.19.y	811218eceeaa	a5f86b15	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/02/04 23:08	linux-4.19.y	811218eceeaa	42b90a7c	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/02/04 19:38	linux-4.19.y	811218eceeaa	42b90a7c	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/02/04 09:47	linux-4.19.y	811218eceeaa	624dad51	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/02/04 08:34	linux-4.19.y	811218eceeaa	624dad51	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/02/04 00:36	linux-4.19.y	811218eceeaa	624dad51	.config	log	report			info	WARNING in __writeback_inodes_sb_nr
ci2-linux-4-19	2021/01/15 22:50	linux-4.19.y	675cc038067f	65a7a854	.config	log	report			info
ci2-linux-4-19	2021/01/09 01:27	linux-4.19.y	4143d798313f	c104d4a3	.config	log	report			info
ci2-linux-4-19	2021/01/07 09:18	linux-4.19.y	4143d798313f	c104d4a3	.config	log	report			info
ci2-linux-4-19	2020/12/25 00:16	linux-4.19.y	13d2ce42de8c	c2c1d1dd	.config	log	report			info
ci2-linux-4-19	2020/12/24 23:25	linux-4.19.y	13d2ce42de8c	c2c1d1dd	.config	log	report			info
ci2-linux-4-19	2020/12/21 17:31	linux-4.19.y	13d2ce42de8c	04201c06	.config	log	report			info
ci2-linux-4-19	2020/12/21 03:08	linux-4.19.y	13d2ce42de8c	04201c06	.config	log	report			info
ci2-linux-4-19	2020/11/30 00:26	linux-4.19.y	0c88e405c97e	a0092f9d	.config	log	report			info
ci2-linux-4-19	2020/10/30 12:48	linux-4.19.y	f5d8eef067ac	a6e3ac3b	.config	log	report			info
ci2-linux-4-19	2020/10/01 05:34	linux-4.19.y	10ad6cfd5736	a9767fb2	.config	log	report			info
ci2-linux-4-19	2020/09/30 11:11	linux-4.19.y	10ad6cfd5736	8516f6d3	.config	log	report			info
ci2-linux-4-19	2020/09/30 09:50	linux-4.19.y	10ad6cfd5736	8516f6d3	.config	log	report			info
ci2-linux-4-19	2020/09/20 20:02	linux-4.19.y	015e94d0e37b	9564d2e9	.config	log	report			info
ci2-linux-4-19	2020/09/20 14:26	linux-4.19.y	015e94d0e37b	9564d2e9	.config	log	report			info