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BUG: KCSAN: data-race in generic_write_end / next_uptodate_page

write to 0xffff88810a458a98 of 8 bytes by task 4499 on cpu 1:
 i_size_write include/linux/fs.h:901 [inline]
 generic_write_end+0x9f/0x240 fs/buffer.c:2304
 ext4_da_write_end+0x49e/0x700 fs/ext4/inode.c:2988
 generic_perform_write+0x26d/0x410 mm/filemap.c:3934
 ext4_buffered_write_iter+0x1f6/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x283/0x1230
 call_write_iter include/linux/fs.h:1871 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4ab/0x7d0 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810a458a98 of 8 bytes by task 4500 on cpu 0:
 i_size_read include/linux/fs.h:879 [inline]
 next_uptodate_page+0x47b/0x560 mm/filemap.c:3465
 first_map_page mm/filemap.c:3482 [inline]
 filemap_map_pages+0x104/0x890 mm/filemap.c:3509
 do_fault_around mm/memory.c:4503 [inline]
 do_read_fault mm/memory.c:4535 [inline]
 do_fault mm/memory.c:4663 [inline]
 do_pte_missing mm/memory.c:3664 [inline]
 handle_pte_fault mm/memory.c:4932 [inline]
 __handle_mm_fault mm/memory.c:5072 [inline]
 handle_mm_fault+0x104d/0x2c10 mm/memory.c:5226
 faultin_page mm/gup.c:959 [inline]
 __get_user_pages+0x65d/0xc30 mm/gup.c:1223
 populate_vma_page_range mm/gup.c:1618 [inline]
 __mm_populate+0x23b/0x360 mm/gup.c:1727
 mm_populate include/linux/mm.h:3194 [inline]
 vm_mmap_pgoff+0x1a3/0x240 mm/util.c:548
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1408
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000c1d000 -> 0x0000000000c1e000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4500 Comm: syz-executor.1 Not tainted 6.4.0-syzkaller-10096-gdfab92f27c60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
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loop1: detected capacity change from 0 to 256