==================================================================
BUG: KCSAN: data-race in delete_from_page_cache_batch / folio_mapping

write to 0xffffea00046a7398 of 8 bytes by task 25819 on cpu 0:
 page_cache_delete_batch mm/filemap.c:311 [inline]
 delete_from_page_cache_batch+0x310/0x720 mm/filemap.c:337
 truncate_inode_pages_range+0x1fe/0x7e0 mm/truncate.c:405
 truncate_inode_pages+0x24/0x30 mm/truncate.c:485
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x1ed/0x270 block/bdev.c:207
 sb_set_blocksize+0x93/0x170 block/bdev.c:240
 sb_min_blocksize+0x53/0x60 block/bdev.c:255
 fat_fill_super+0x32b/0x1c10 fs/fat/inode.c:1603
 vfat_fill_super+0x24/0x30 fs/fat/namei_vfat.c:1202
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 vfat_get_tree+0x1c/0x30 fs/fat/namei_vfat.c:1207
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3834
 path_mount+0x4d0/0xbc0 fs/namespace.c:4154
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffea00046a7398 of 8 bytes by task 25826 on cpu 1:
 folio_mapping+0xa1/0xe0 mm/util.c:732
 folio_evictable mm/internal.h:584 [inline]
 lru_add+0x8d/0x460 mm/swap.c:136
 folio_batch_move_lru+0x1d3/0x290 mm/swap.c:172
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x14f/0x1f0 mm/swap.c:517
 folio_add_lru_vma+0x49/0x70 mm/swap.c:536
 wp_page_copy mm/memory.c:3943 [inline]
 do_wp_page+0x13b1/0x2040 mm/memory.c:4336
 handle_pte_fault mm/memory.c:6443 [inline]
 __handle_mm_fault mm/memory.c:6565 [inline]
 handle_mm_fault+0x8bb/0x2e70 mm/memory.c:6734
 do_user_addr_fault+0x62f/0x1050 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

value changed: 0xffff88810048d928 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 25826 Comm: syz.3.5358 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
==================================================================