syzbot

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BUG: KCSAN: data-race in ext4_setattr / filemap_map_pages

write to 0xffff88811d053578 of 8 bytes by task 15861 on cpu 1:
 i_size_write include/linux/fs.h:894 [inline]
 ext4_setattr+0xd58/0x1320 fs/ext4/inode.c:5365
 notify_change+0x82b/0xad0 fs/attr.c:336
 do_truncate+0xf9/0x180 fs/open.c:64
 handle_truncate fs/namei.c:2887 [inline]
 do_open fs/namei.c:3233 [inline]
 path_openat+0x1e51/0x23d0 fs/namei.c:3346
 do_filp_open+0x11e/0x1b0 fs/namei.c:3373
 do_sys_openat2+0x52e/0x680 fs/open.c:1148
 do_sys_open+0xa2/0x110 fs/open.c:1164
 __do_sys_openat fs/open.c:1178 [inline]
 __se_sys_openat fs/open.c:1173 [inline]
 __x64_sys_openat+0x5d/0x70 fs/open.c:1173
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811d053578 of 8 bytes by task 15869 on cpu 0:
 filemap_map_pages+0x8da/0xa50 mm/filemap.c:2628
 do_fault_around mm/memory.c:3807 [inline]
 do_read_fault mm/memory.c:3841 [inline]
 do_fault mm/memory.c:3975 [inline]
 handle_pte_fault mm/memory.c:4215 [inline]
 __handle_mm_fault+0x2ba6/0x2da0 mm/memory.c:4345
 handle_mm_fault+0x21c/0x540 mm/memory.c:4382
 faultin_page mm/gup.c:879 [inline]
 __get_user_pages+0x533/0x11c0 mm/gup.c:1098
 populate_vma_page_range+0xdc/0x100 mm/gup.c:1430
 __mm_populate+0x168/0x2b0 mm/gup.c:1478
 mm_populate include/linux/mm.h:2562 [inline]
 vm_mmap_pgoff+0x185/0x190 mm/util.c:511
 ksys_mmap_pgoff+0x2db/0x420 mm/mmap.c:1595
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15869 Comm: syz-executor.0 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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