syzbot

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BUG: KCSAN: data-race in compact_zone / compact_zone

write to 0xffff88813fffc290 of 8 bytes by task 25217 on cpu 1:
 update_cached_migrate mm/compaction.c:435 [inline]
 isolate_migratepages mm/compaction.c:1843 [inline]
 compact_zone+0x1397/0x1d30 mm/compaction.c:2290
 compact_zone_order mm/compaction.c:2434 [inline]
 try_to_compact_pages+0x28e/0x580 mm/compaction.c:2492
 __alloc_pages_direct_compact+0x89/0x1a0 mm/page_alloc.c:4108
 __alloc_pages_slowpath+0x5af/0x9c0 mm/page_alloc.c:4761
 __alloc_pages_nodemask+0x269/0x350 mm/page_alloc.c:4965
 __alloc_pages include/linux/gfp.h:511 [inline]
 __alloc_pages_node include/linux/gfp.h:524 [inline]
 alloc_pages_vma+0x718/0x890 mm/mempolicy.c:2215
 shmem_alloc_hugepage mm/shmem.c:1548 [inline]
 shmem_alloc_and_acct_page+0x3e6/0x650 mm/shmem.c:1588
 shmem_getpage_gfp+0x568/0x1960 mm/shmem.c:1890
 shmem_getpage mm/shmem.c:155 [inline]
 shmem_write_begin+0x80/0x100 mm/shmem.c:2533
 generic_perform_write+0x196/0x3a0 mm/filemap.c:3311
 __generic_file_write_iter+0x15c/0x330 mm/filemap.c:3440
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3472
 call_write_iter include/linux/fs.h:1887 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x617/0x690 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

read to 0xffff88813fffc290 of 8 bytes by task 25221 on cpu 0:
 update_cached_migrate mm/compaction.c:434 [inline]
 isolate_migratepages mm/compaction.c:1843 [inline]
 compact_zone+0x1373/0x1d30 mm/compaction.c:2290
 compact_zone_order mm/compaction.c:2434 [inline]
 try_to_compact_pages+0x28e/0x580 mm/compaction.c:2492
 __alloc_pages_direct_compact+0x89/0x1a0 mm/page_alloc.c:4108
 __alloc_pages_slowpath+0x2b5/0x9c0 mm/page_alloc.c:4679
 __alloc_pages_nodemask+0x269/0x350 mm/page_alloc.c:4965
 __alloc_pages include/linux/gfp.h:511 [inline]
 __alloc_pages_node include/linux/gfp.h:524 [inline]
 alloc_pages_vma+0x718/0x890 mm/mempolicy.c:2215
 shmem_alloc_hugepage mm/shmem.c:1548 [inline]
 shmem_alloc_and_acct_page+0x3e6/0x650 mm/shmem.c:1588
 shmem_getpage_gfp+0x568/0x1960 mm/shmem.c:1890
 shmem_getpage mm/shmem.c:155 [inline]
 shmem_write_begin+0x80/0x100 mm/shmem.c:2533
 generic_perform_write+0x196/0x3a0 mm/filemap.c:3311
 __generic_file_write_iter+0x15c/0x330 mm/filemap.c:3440
 generic_file_write_iter+0x75/0x130 mm/filemap.c:3472
 call_write_iter include/linux/fs.h:1887 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x617/0x690 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: 0 PID: 25221 Comm: syz-executor.0 Not tainted 5.10.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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