syzbot

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BUG: KCSAN: data-race in dec_zone_page_state / release_pages

write to 0xffffea000481bf40 of 8 bytes by task 12791 on cpu 0:
 instrument_write include/linux/instrumented.h:42 [inline]
 __clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:42 [inline]
 __ClearPageLRU include/linux/page-flags.h:328 [inline]
 release_pages+0x3cb/0xa60 mm/swap.c:849
 __pagevec_release+0x4d/0x80 mm/swap.c:883
 pagevec_release include/linux/pagevec.h:88 [inline]
 invalidate_mapping_pages+0x676/0x860 mm/truncate.c:620
 generic_fadvise+0x322/0x490 mm/fadvise.c:170
 vfs_fadvise+0x8a/0x90 mm/fadvise.c:187
 ksys_fadvise64_64+0x5b/0xa0 mm/fadvise.c:201
 __do_sys_fadvise64 mm/fadvise.c:216 [inline]
 __se_sys_fadvise64 mm/fadvise.c:214 [inline]
 __x64_sys_fadvise64+0x5a/0x70 mm/fadvise.c:214
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffea000481bf40 of 8 bytes by task 29 on cpu 1:
 page_zone include/linux/mm.h:1411 [inline]
 dec_zone_page_state+0x1d/0xd0 mm/vmstat.c:533
 test_clear_page_writeback+0x33f/0x7e0 mm/page-writeback.c:2757
 end_page_writeback+0x98/0x180 mm/filemap.c:1317
 ext4_finish_bio+0x39b/0x460 fs/ext4/page-io.c:146
 ext4_release_io_end+0xc5/0x270 fs/ext4/page-io.c:161
 ext4_end_io_end fs/ext4/page-io.c:195 [inline]
 ext4_do_flush_completed_IO fs/ext4/page-io.c:260 [inline]
 ext4_end_io_rsv_work+0x159/0x400 fs/ext4/page-io.c:274
 process_one_work+0x424/0x930 kernel/workqueue.c:2268
 worker_thread+0x9a/0x7e0 kernel/workqueue.c:2414
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29 Comm: kworker/u4:2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
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