================================================================== BUG: KCSAN: data-race in ext4_has_free_clusters / percpu_counter_add_batch write to 0xffff8881297b0158 of 8 bytes by task 4450 on cpu 1: percpu_counter_add_batch+0xbc/0x140 lib/percpu_counter.c:91 percpu_counter_add include/linux/percpu_counter.h:55 [inline] percpu_counter_sub include/linux/percpu_counter.h:189 [inline] ext4_mb_mark_diskspace_used+0x902/0xa00 fs/ext4/mballoc.c:3016 ext4_mb_new_blocks+0x714/0x1ea0 fs/ext4/mballoc.c:4560 ext4_ext_map_blocks+0x1a5c/0x20f0 fs/ext4/extents.c:4440 ext4_map_blocks+0x230/0xcf0 fs/ext4/inode.c:622 ext4_alloc_file_blocks+0x22f/0x6f0 fs/ext4/extents.c:4629 ext4_fallocate+0x9ec/0x2240 fs/ext4/extents.c:4910 vfs_fallocate+0x3b1/0x650 fs/open.c:309 ioctl_preallocate+0x12a/0x190 fs/ioctl.c:504 file_ioctl fs/ioctl.c:544 [inline] do_vfs_ioctl+0xa6b/0xd00 fs/ioctl.c:742 ksys_ioctl+0xb2/0x150 fs/ioctl.c:761 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8881297b0158 of 8 bytes by task 4451 on cpu 0: 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: 0 PID: 4451 Comm: syz-executor.3 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================