syzbot

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

write to 0xffffea000475b398 of 8 bytes by task 3753 on cpu 0:
 page_cache_delete_batch mm/filemap.c:306 [inline]
 delete_from_page_cache_batch+0x2f6/0x6f0 mm/filemap.c:332
 truncate_inode_pages_range+0x1b8/0x690 mm/truncate.c:380
 truncate_inode_pages+0x24/0x30 mm/truncate.c:460
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x259/0x310 block/bdev.c:207
 sb_set_blocksize block/bdev.c:224 [inline]
 sb_min_blocksize+0xb8/0x140 block/bdev.c:239
 ext4_load_super fs/ext4/super.c:5046 [inline]
 __ext4_fill_super fs/ext4/super.c:5267 [inline]
 ext4_fill_super+0x390/0x35d0 fs/ext4/super.c:5728
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1692
 get_tree_bdev+0x1f/0x30 fs/super.c:1715
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5760
 vfs_get_tree+0x54/0x1d0 fs/super.c:1815
 do_new_mount+0x207/0x5e0 fs/namespace.c:3808
 path_mount+0x4a4/0xb20 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324
 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffea000475b398 of 8 bytes by task 3715 on cpu 1:
 folio_mapping+0xa1/0x120 mm/util.c:702
 folio_evictable mm/internal.h:499 [inline]
 lru_add+0x80/0x430 mm/swap.c:136
 folio_batch_move_lru+0x177/0x230 mm/swap.c:168
 lru_add_drain_cpu+0x77/0x250 mm/swap.c:647
 lru_add_drain mm/swap.c:735 [inline]
 __folio_batch_release+0x44/0xb0 mm/swap.c:1054
 folio_batch_release include/linux/pagevec.h:101 [inline]
 mpage_prepare_extent_to_map+0xb83/0xc00 fs/ext4/inode.c:2751
 ext4_do_writepages+0x708/0x2750 fs/ext4/inode.c:2877
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:3025
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2634
 __writeback_single_inode+0x80/0x7c0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x48f/0xa30 fs/fs-writeback.c:1976
 wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x194/0x910 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0xffff8881004811a0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3715 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: writeback wb_workfn (flush-7:2)
==================================================================
EXT4-fs error (device loop2): ext4_mb_generate_buddy:1289: group 0, block bitmap and bg descriptor inconsistent: 96 vs 65376 free clusters
EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 2048 with error 28
EXT4-fs (loop2): This should not happen!! Data will be lost

EXT4-fs (loop2): Total free blocks count 0
EXT4-fs (loop2): Free/Dirty block details
EXT4-fs (loop2): free_blocks=65280
EXT4-fs (loop2): dirty_blocks=8193
EXT4-fs (loop2): Block reservation details
EXT4-fs (loop2): i_reserved_data_blocks=8193