==================================================================
BUG: KCSAN: data-race in ext4_ext_insert_extent / ext4_mark_iloc_dirty

write to 0xffff88810eb73102 of 2 bytes by task 12765 on cpu 0:
 le16_add_cpu include/linux/byteorder/generic.h:146 [inline]
 ext4_ext_insert_extent+0x11e6/0x2bc0 fs/ext4/extents.c:2113
 ext4_ext_map_blocks+0x1597/0x1fd0 fs/ext4/extents.c:4259
 ext4_map_blocks+0x726/0xff0 fs/ext4/inode.c:637
 mpage_map_one_extent+0x10d/0x3a0 fs/ext4/inode.c:2396
 mpage_map_and_submit_extent fs/ext4/inode.c:2449 [inline]
 ext4_writepages+0xa51/0x1e70 fs/ext4/inode.c:2801
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:422
 filemap_write_and_wait_range+0x8b/0x2a0 mm/filemap.c:655
 filemap_write_and_wait include/linux/fs.h:2647 [inline]
 iomap_bmap+0x68/0x110 fs/iomap/fiemap.c:130
 ext4_bmap+0x211/0x220 fs/ext4/inode.c:3234
 bmap+0x56/0x80 fs/inode.c:1704
 ioctl_fibmap fs/ioctl.c:74 [inline]
 file_ioctl fs/ioctl.c:531 [inline]
 do_vfs_ioctl+0xd38/0xec0 fs/ioctl.c:732
 __do_sys_ioctl fs/ioctl.c:751 [inline]
 __se_sys_ioctl+0x83/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810eb73100 of 4 bytes by task 12762 on cpu 1:
 ext4_do_update_inode fs/ext4/inode.c:5114 [inline]
 ext4_mark_iloc_dirty+0xc8e/0x16f0 fs/ext4/inode.c:5725
 __ext4_mark_inode_dirty+0x4d6/0x5e0 fs/ext4/inode.c:5919
 ext4_dirty_inode+0xa6/0xc0 fs/ext4/inode.c:5955
 __mark_inode_dirty+0x72/0x6b0 fs/fs-writeback.c:2262
 mark_inode_dirty include/linux/fs.h:2181 [inline]
 generic_write_end+0x166/0x240 fs/buffer.c:2202
 ext4_da_write_end+0x59b/0x760 fs/ext4/inode.c:3111
 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3419
 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:270
 ext4_file_write_iter+0x47a/0x1060 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x6f0/0x7e0 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 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: 12762 Comm: syz-executor.4 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================