================================================================== BUG: KCSAN: data-race in ext4_set_iomap / writeback_single_inode write to 0xffff88811046b340 of 8 bytes by task 31676 on cpu 0: writeback_single_inode+0x102/0x580 fs/fs-writeback.c:1567 sync_inode fs/fs-writeback.c:2605 [inline] sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2625 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline] ext4_sync_file+0x335/0x6e0 fs/ext4/fsync.c:170 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2747 [inline] ext4_buffered_write_iter+0x369/0x3b0 fs/ext4/file.c:276 ext4_file_write_iter+0x768/0x1060 include/linux/fs.h:784 call_write_iter include/linux/fs.h:1882 [inline] do_iter_readv_writev+0x32e/0x3d0 fs/read_write.c:713 do_iter_write+0x112/0x4b0 fs/read_write.c:1018 vfs_iter_write+0x4c/0x70 fs/read_write.c:1059 iter_file_splice_write+0x41a/0x770 fs/splice.c:750 do_splice_from fs/splice.c:846 [inline] direct_splice_actor+0x95/0x160 fs/splice.c:1016 splice_direct_to_actor+0x365/0x660 fs/splice.c:971 do_splice_direct+0xf2/0x170 fs/splice.c:1059 do_sendfile+0x56a/0xba0 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1595 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1587 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88811046b340 of 8 bytes by task 31672 on cpu 1: ext4_inode_datasync_dirty fs/ext4/inode.c:3305 [inline] ext4_set_iomap+0x138/0x3e0 fs/ext4/inode.c:3320 ext4_iomap_begin+0x5a0/0x5f0 fs/ext4/inode.c:3447 iomap_apply+0x8b/0x540 fs/iomap/apply.c:46 iomap_dio_rw+0x434/0x980 fs/iomap/direct-io.c:506 ext4_dio_read_iter fs/ext4/file.c:77 [inline] ext4_file_read_iter+0x3be/0x420 fs/ext4/file.c:129 call_read_iter include/linux/fs.h:1876 [inline] generic_file_splice_read+0x22b/0x310 fs/splice.c:312 do_splice_to fs/splice.c:870 [inline] splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950 do_splice_direct+0xf2/0x170 fs/splice.c:1059 do_sendfile+0x56a/0xba0 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 31672 Comm: syz-executor.1 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================