================================================================== BUG: KCSAN: data-race in ext4_has_free_clusters / percpu_counter_add_batch write to 0xffff8881290b5958 of 8 bytes by task 16157 on cpu 0: percpu_counter_add_batch+0xbc/0x140 lib/percpu_counter.c:91 percpu_counter_add include/linux/percpu_counter.h:55 [inline] ext4_claim_free_clusters+0x64/0x80 fs/ext4/balloc.c:602 ext4_da_reserve_space+0xf8/0x270 fs/ext4/inode.c:1464 ext4_insert_delayed_block fs/ext4/inode.c:1632 [inline] ext4_da_map_blocks fs/ext4/inode.c:1747 [inline] ext4_da_get_block_prep+0x87e/0xa50 fs/ext4/inode.c:1811 ext4_block_write_begin+0x336/0xbd0 fs/ext4/inode.c:1054 ext4_da_write_begin+0x220/0x860 fs/ext4/inode.c:2997 generic_perform_write+0x13a/0x320 mm/filemap.c:3287 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x303/0x400 fs/read_write.c:483 __vfs_write+0x9e/0xb0 fs/read_write.c:496 vfs_write fs/read_write.c:558 [inline] vfs_write+0x189/0x380 fs/read_write.c:542 ksys_write+0xc5/0x1a0 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x49/0x60 fs/read_write.c:620 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8881290b5958 of 8 bytes by task 16165 on cpu 1: ext4_has_free_clusters+0x61/0x310 fs/ext4/balloc.c:558 ext4_claim_free_clusters+0x2c/0x80 fs/ext4/balloc.c:601 ext4_da_reserve_space+0xf8/0x270 fs/ext4/inode.c:1464 ext4_insert_delayed_block fs/ext4/inode.c:1632 [inline] ext4_da_map_blocks fs/ext4/inode.c:1747 [inline] ext4_da_get_block_prep+0x87e/0xa50 fs/ext4/inode.c:1811 ext4_block_write_begin+0x336/0xbd0 fs/ext4/inode.c:1054 ext4_da_write_begin+0x220/0x860 fs/ext4/inode.c:2997 generic_perform_write+0x13a/0x320 mm/filemap.c:3287 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x303/0x400 fs/read_write.c:483 __vfs_write+0x9e/0xb0 fs/read_write.c:496 vfs_write fs/read_write.c:558 [inline] vfs_write+0x189/0x380 fs/read_write.c:542 ksys_write+0xc5/0x1a0 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x49/0x60 fs/read_write.c:620 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 16165 Comm: syz-executor.4 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================