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BUG: KCSAN: data-race in file_update_time / generic_update_time

read to 0xffff8881299ad9d8 of 8 bytes by task 18929 on cpu 0:
 file_update_time+0x12a/0x2d0 fs/inode.c:1897
 filemap_page_mkwrite+0xb3/0x1d0 mm/filemap.c:2663
 do_page_mkwrite+0xfa/0x210 mm/memory.c:2529
 do_shared_fault mm/memory.c:3911 [inline]
 do_fault mm/memory.c:3979 [inline]
 handle_pte_fault mm/memory.c:4215 [inline]
 __handle_mm_fault+0x2828/0x2da0 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
 __get_user_pages_locked mm/gup.c:1284 [inline]
 get_user_pages_unlocked+0x13b/0x5d0 mm/gup.c:2033
 __gup_longterm_unlocked mm/gup.c:2739 [inline]
 internal_get_user_pages_fast+0x2ed/0x320 mm/gup.c:2780
 get_user_pages_fast+0x53/0x80 mm/gup.c:2828
 iov_iter_get_pages+0x1d3/0x8cc lib/iov_iter.c:1323
 __bio_iov_iter_get_pages block/bio.c:989 [inline]
 bio_iov_iter_get_pages+0x106/0x620 block/bio.c:1045
 __blkdev_direct_IO fs/block_dev.c:387 [inline]
 blkdev_direct_IO+0x5e3/0xab0 fs/block_dev.c:477
 generic_file_read_iter+0x1aa/0x18c0 mm/filemap.c:2288
 blkdev_read_iter+0xae/0xe0 fs/block_dev.c:2053
 call_read_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x570/0x5d0 fs/read_write.c:692
 do_iter_read+0x1e6/0x3a0 fs/read_write.c:934
 vfs_readv+0x9c/0xf0 fs/read_write.c:1054
 do_preadv+0x129/0x1c0 fs/read_write.c:1146
 __do_sys_preadv fs/read_write.c:1196 [inline]
 __se_sys_preadv fs/read_write.c:1191 [inline]
 __x64_sys_preadv+0x5e/0x80 fs/read_write.c:1191
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881299ad9d8 of 16 bytes by task 18925 on cpu 1:
 generic_update_time+0xc2/0x270 fs/inode.c:1673
 update_time+0x7d/0x90 fs/inode.c:1695
 file_update_time+0x205/0x2d0 fs/inode.c:1910
 filemap_page_mkwrite+0xb3/0x1d0 mm/filemap.c:2663
 do_page_mkwrite+0xfa/0x210 mm/memory.c:2529
 do_shared_fault mm/memory.c:3911 [inline]
 do_fault mm/memory.c:3979 [inline]
 handle_pte_fault mm/memory.c:4215 [inline]
 __handle_mm_fault+0x2828/0x2da0 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
 __get_user_pages_locked mm/gup.c:1284 [inline]
 get_user_pages_unlocked+0x13b/0x5d0 mm/gup.c:2033
 __gup_longterm_unlocked mm/gup.c:2739 [inline]
 internal_get_user_pages_fast+0x2ed/0x320 mm/gup.c:2780
 get_user_pages_fast+0x53/0x80 mm/gup.c:2828
 iov_iter_get_pages+0x1d3/0x8cc lib/iov_iter.c:1323
 __bio_iov_iter_get_pages block/bio.c:989 [inline]
 bio_iov_iter_get_pages+0x106/0x620 block/bio.c:1045
 __blkdev_direct_IO fs/block_dev.c:387 [inline]
 blkdev_direct_IO+0x5e3/0xab0 fs/block_dev.c:477
 generic_file_read_iter+0x1aa/0x18c0 mm/filemap.c:2288
 blkdev_read_iter+0xae/0xe0 fs/block_dev.c:2053
 call_read_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x570/0x5d0 fs/read_write.c:692
 do_iter_read+0x1e6/0x3a0 fs/read_write.c:934
 vfs_readv+0x9c/0xf0 fs/read_write.c:1054
 do_preadv+0x129/0x1c0 fs/read_write.c:1146
 __do_sys_preadv fs/read_write.c:1196 [inline]
 __se_sys_preadv fs/read_write.c:1191 [inline]
 __x64_sys_preadv+0x5e/0x80 fs/read_write.c:1191
 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: 18925 Comm: syz-executor.4 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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