BUG: KCSAN: data-race in atime_needs_update / touch_atime

read to 0xffff888161f7cca0 of 8 bytes by task 11897 on cpu 1:
 atime_needs_update+0x264/0x3f0
 touch_atime+0x4a/0x340 fs/inode.c:1973
 file_accessed include/linux/fs.h:2437 [inline]
 shmem_file_read_iter+0x4b3/0x550 mm/shmem.c:2873
 do_iter_readv_writev+0x2b0/0x330
 vfs_iter_read+0x172/0x390 fs/read_write.c:830
 lo_read_simple drivers/block/loop.c:286 [inline]
 do_req_filebacked drivers/block/loop.c:496 [inline]
 loop_handle_cmd drivers/block/loop.c:1909 [inline]
 loop_process_work+0x7a1/0x10e0 drivers/block/loop.c:1944
 loop_rootcg_workfn+0x22/0x30 drivers/block/loop.c:1975
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706
 worker_thread+0x525/0x730 kernel/workqueue.c:2787
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

write to 0xffff888161f7cca0 of 8 bytes by task 26 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1541 [inline]
 inode_update_timestamps fs/inode.c:1876 [inline]
 generic_update_time fs/inode.c:1898 [inline]
 inode_update_time fs/inode.c:1918 [inline]
 touch_atime+0x1ed/0x340 fs/inode.c:1990
 file_accessed include/linux/fs.h:2437 [inline]
 shmem_file_read_iter+0x4b3/0x550 mm/shmem.c:2873
 do_iter_readv_writev+0x2b0/0x330
 vfs_iter_read+0x172/0x390 fs/read_write.c:830
 lo_read_simple drivers/block/loop.c:286 [inline]
 do_req_filebacked drivers/block/loop.c:496 [inline]
 loop_handle_cmd drivers/block/loop.c:1909 [inline]
 loop_process_work+0x7a1/0x10e0 drivers/block/loop.c:1944
 loop_workfn+0x31/0x40 drivers/block/loop.c:1968
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706
 worker_thread+0x525/0x730 kernel/workqueue.c:2787
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x0000000029b91ff6 -> 0x000000002a51b676

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26 Comm: kworker/u4:1 Not tainted 6.8.0-rc3-syzkaller-00005-g99bd3cb0d12e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: loop2 loop_workfn
==================================================================
netdevsim netdevsim4 netdevsim3 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim4 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim4 netdevsim2 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim4 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim4 netdevsim1 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim4 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim4 netdevsim0 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim4 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Released all slaves
IPVS: stop unused estimator thread 0...