EXT4-fs warning (device loop3): ext4_convert_unwritten_extents:4940: inode #15: block 1: len 3: ext4_ext_map_blocks returned -30
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BUG: KCSAN: data-race in touch_atime / touch_atime

write to 0xffff88811d01e9a0 of 4 bytes by task 317 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1684 [inline]
 inode_update_timestamps fs/inode.c:2035 [inline]
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 touch_atime+0x1e8/0x340 fs/inode.c:2149
 file_accessed include/linux/fs.h:2652 [inline]
 shmem_file_read_iter+0x477/0x540 mm/shmem.c:3447
 lo_rw_aio+0x6ed/0x7a0 include/linux/fs.h:-1
 do_req_filebacked drivers/block/loop.c:-1 [inline]
 loop_handle_cmd drivers/block/loop.c:1889 [inline]
 loop_process_work+0x52d/0xa60 drivers/block/loop.c:1924
 loop_rootcg_workfn+0x22/0x30 drivers/block/loop.c:1955
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88811d01e9a0 of 4 bytes by task 114 on cpu 1:
 inode_get_atime_nsec include/linux/fs.h:1669 [inline]
 inode_get_atime include/linux/fs.h:1675 [inline]
 inode_update_timestamps fs/inode.c:2032 [inline]
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 touch_atime+0x194/0x340 fs/inode.c:2149
 file_accessed include/linux/fs.h:2652 [inline]
 shmem_file_read_iter+0x477/0x540 mm/shmem.c:3447
 lo_rw_aio+0x6ed/0x7a0 include/linux/fs.h:-1
 do_req_filebacked drivers/block/loop.c:-1 [inline]
 loop_handle_cmd drivers/block/loop.c:1889 [inline]
 loop_process_work+0x52d/0xa60 drivers/block/loop.c:1924
 loop_workfn+0x31/0x40 drivers/block/loop.c:1948
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x032cca06 -> 0x03b762d2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 114 Comm: kworker/u8:4 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: loop4 loop_workfn
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