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BUG: KCSAN: data-race in __percpu_counter_compare / percpu_counter_add_batch

write to 0xffff888100876f10 of 8 bytes by task 21585 on cpu 1:
 percpu_counter_add_batch+0xb4/0x130 lib/percpu_counter.c:91
 percpu_counter_add include/linux/percpu_counter.h:56 [inline]
 shmem_inode_acct_block mm/shmem.c:222 [inline]
 shmem_alloc_and_acct_page mm/shmem.c:1564 [inline]
 shmem_getpage_gfp+0x828/0x12c0 mm/shmem.c:1868
 shmem_getpage mm/shmem.c:149 [inline]
 shmem_write_begin+0x7e/0x100 mm/shmem.c:2437
 generic_perform_write+0x1c8/0x400 mm/filemap.c:3765
 __generic_file_write_iter+0xf7/0x2b0 mm/filemap.c:3892
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3924
 call_write_iter include/linux/fs.h:2074 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100876f10 of 8 bytes by task 21591 on cpu 0:
 percpu_counter_read include/linux/percpu_counter.h:72 [inline]
 __percpu_counter_compare+0x28/0x1a0 lib/percpu_counter.c:225
 percpu_counter_compare include/linux/percpu_counter.h:51 [inline]
 shmem_inode_acct_block mm/shmem.c:219 [inline]
 shmem_alloc_and_acct_page mm/shmem.c:1564 [inline]
 shmem_getpage_gfp+0x7b7/0x12c0 mm/shmem.c:1868
 shmem_getpage mm/shmem.c:149 [inline]
 shmem_write_begin+0x7e/0x100 mm/shmem.c:2437
 generic_perform_write+0x1c8/0x400 mm/filemap.c:3765
 __generic_file_write_iter+0xf7/0x2b0 mm/filemap.c:3892
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3924
 call_write_iter include/linux/fs.h:2074 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000001b60 -> 0x0000000000001b80

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21591 Comm: syz-executor.1 Not tainted 5.17.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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