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BUG: KCSAN: data-race in touch_atime / touch_atime

write to 0xffff88812223ce58 of 4 bytes by task 12305 on cpu 1:
 inode_set_atime_to_ts include/linux/fs.h:1626 [inline]
 inode_update_atime fs/inode.c:2098 [inline]
 inode_update_time fs/inode.c:2156 [inline]
 generic_update_time fs/inode.c:2189 [inline]
 touch_atime+0x1d7/0x330 fs/inode.c:2267
 file_accessed include/linux/fs.h:2263 [inline]
 shmem_file_read_iter+0x477/0x540 mm/shmem.c:3484
 lo_rw_aio+0x67d/0x730 drivers/block/loop.c:-1
 do_req_filebacked drivers/block/loop.c:-1 [inline]
 loop_handle_cmd drivers/block/loop.c:1925 [inline]
 loop_process_work+0x56c/0xac0 drivers/block/loop.c:1960
 loop_workfn+0x31/0x40 drivers/block/loop.c:1984
 process_one_work kernel/workqueue.c:3288 [inline]
 process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3371
 worker_thread+0x58a/0x780 kernel/workqueue.c:3452
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88812223ce58 of 4 bytes by task 12278 on cpu 0:
 inode_get_atime_nsec include/linux/fs.h:1611 [inline]
 inode_get_atime include/linux/fs.h:1617 [inline]
 inode_update_atime fs/inode.c:2092 [inline]
 inode_update_time fs/inode.c:2156 [inline]
 generic_update_time fs/inode.c:2189 [inline]
 touch_atime+0x16c/0x330 fs/inode.c:2267
 file_accessed include/linux/fs.h:2263 [inline]
 shmem_file_read_iter+0x477/0x540 mm/shmem.c:3484
 lo_rw_aio+0x67d/0x730 drivers/block/loop.c:-1
 do_req_filebacked drivers/block/loop.c:-1 [inline]
 loop_handle_cmd drivers/block/loop.c:1925 [inline]
 loop_process_work+0x56c/0xac0 drivers/block/loop.c:1960
 loop_rootcg_workfn+0x22/0x30 drivers/block/loop.c:1991
 process_one_work kernel/workqueue.c:3288 [inline]
 process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3371
 worker_thread+0x58a/0x780 kernel/workqueue.c:3452
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x35af33d8 -> 0x3647ca58

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 12278 Comm: kworker/u8:23 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: loop2 loop_rootcg_workfn
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