syzbot

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BUG: KCSAN: data-race in __add_to_page_cache_locked / truncate_inode_pages_range

write to 0xffff88808e23a900 of 8 bytes by task 11817 on cpu 0:
 __add_to_page_cache_locked+0x28a/0x800 mm/filemap.c:868
 add_to_page_cache_lru+0xc7/0x260 mm/filemap.c:921
 ext4_mpage_readpages+0x31c/0x14d0 fs/ext4/readpage.c:259
 ext4_readpages+0x8e/0xb0 fs/ext4/inode.c:3243
 read_pages+0xa2/0x360 mm/readahead.c:126
 __do_page_cache_readahead+0x358/0x380 mm/readahead.c:212
 ra_submit mm/internal.h:62 [inline]
 ondemand_readahead+0x369/0x730 mm/readahead.c:492
 page_cache_async_readahead+0x237/0x260 mm/readahead.c:574
 generic_file_buffered_read mm/filemap.c:2044 [inline]
 generic_file_read_iter+0x1077/0x18c0 mm/filemap.c:2309
 ext4_file_read_iter fs/ext4/file.c:131 [inline]
 ext4_file_read_iter+0x103/0x360 fs/ext4/file.c:114
 call_read_iter include/linux/fs.h:1901 [inline]
 new_sync_read+0x306/0x450 fs/read_write.c:415
 __vfs_read+0x9e/0xb0 fs/read_write.c:428
 vfs_read fs/read_write.c:462 [inline]
 vfs_read+0x13e/0x2b0 fs/read_write.c:447
 ksys_read+0xc5/0x1a0 fs/read_write.c:588
 __do_sys_read fs/read_write.c:598 [inline]
 __se_sys_read fs/read_write.c:596 [inline]
 __x64_sys_read+0x49/0x60 fs/read_write.c:596
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88808e23a900 of 8 bytes by task 11823 on cpu 1:
 truncate_inode_pages_range+0x4d/0x1130 mm/truncate.c:303
 truncate_pagecache_range+0x71/0xa0 mm/truncate.c:931
 ext4_punch_hole+0x2dd/0xab0 fs/ext4/inode.c:4030
 ext4_fallocate+0x29e/0x21f0 fs/ext4/extents.c:4630
 vfs_fallocate+0x3b1/0x640 fs/open.c:309
 madvise_remove mm/madvise.c:856 [inline]
 madvise_vma mm/madvise.c:939 [inline]
 do_madvise mm/madvise.c:1127 [inline]
 do_madvise+0x815/0x12c0 mm/madvise.c:1053
 __do_sys_madvise mm/madvise.c:1153 [inline]
 __se_sys_madvise mm/madvise.c:1151 [inline]
 __x64_sys_madvise+0x48/0x60 mm/madvise.c:1151
 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: 1 PID: 11823 Comm: syz-executor.1 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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