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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff8881004c3578 of 8 bytes by task 4147 on cpu 1:
 __filemap_add_folio+0x6c4/0x930 mm/filemap.c:918
 filemap_add_folio+0x1cd/0x380 mm/filemap.c:970
 __filemap_get_folio_mpol+0x309/0x830 mm/filemap.c:2057
 __filemap_get_folio include/linux/pagemap.h:758 [inline]
 grow_dev_folio fs/buffer.c:856 [inline]
 grow_buffers fs/buffer.c:922 [inline]
 __getblk_slow fs/buffer.c:940 [inline]
 bdev_getblk+0x127/0x370 fs/buffer.c:1350
 sb_getblk_gfp include/linux/buffer_head.h:448 [inline]
 __ext4_sb_bread_gfp fs/ext4/super.c:248 [inline]
 ext4_sb_bread_unmovable+0x65/0x180 fs/ext4/super.c:277
 ext4_load_super fs/ext4/super.c:5214 [inline]
 __ext4_fill_super fs/ext4/super.c:5420 [inline]
 ext4_fill_super+0x44b/0x37d0 fs/ext4/super.c:5899
 get_tree_bdev_flags+0x297/0x300 fs/super.c:1821
 get_tree_bdev+0x1f/0x30 fs/super.c:1844
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5931
 vfs_get_tree+0x57/0x1d0 fs/super.c:1881
 fc_mount fs/namespace.c:1282 [inline]
 do_new_mount_fc fs/namespace.c:3910 [inline]
 do_new_mount+0x288/0x730 fs/namespace.c:3986
 path_mount+0x4ad/0xba0 fs/namespace.c:4337
 do_mount fs/namespace.c:4350 [inline]
 __do_sys_mount fs/namespace.c:4565 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4542
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4542
 x64_sys_call+0xc3b/0x2550 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x116/0x380 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881004c3578 of 8 bytes by task 2985 on cpu 0:
 mapping_needs_writeback mm/filemap.c:633 [inline]
 filemap_write_and_wait_range+0x59/0x370 mm/filemap.c:682
 filemap_write_and_wait include/linux/pagemap.h:64 [inline]
 sync_blockdev block/bdev.c:275 [inline]
 bdev_release+0xd4/0x3d0 block/bdev.c:1171
 blkdev_release+0x15/0x20 block/fops.c:690
 __fput+0x286/0x610 fs/file_table.c:512
 fput_close_sync+0xad/0x190 fs/file_table.c:618
 filp_close_sync fs/open.c:1574 [inline]
 __do_sys_close fs/open.c:1597 [inline]
 __se_sys_close fs/open.c:1584 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1584
 x64_sys_call+0x812/0x2550 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x116/0x380 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2985 Comm: udevd Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
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