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BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

read-write to 0xffff888237c2ba28 of 8 bytes by task 24289 on cpu 0:
 bh_lru_install fs/buffer.c:1337 [inline]
 __find_get_block+0x42e/0x890 fs/buffer.c:1400
 bdev_getblk+0x30/0x3b0 fs/buffer.c:1425
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 ext4_read_block_bitmap_nowait+0x165/0x680 fs/ext4/balloc.c:488
 ext4_read_block_bitmap+0x20/0x70 fs/ext4/balloc.c:600
 ext4_mb_mark_context+0x9a/0x900 fs/ext4/mballoc.c:3997
 ext4_mb_clear_bb fs/ext4/mballoc.c:6467 [inline]
 ext4_free_blocks+0x801/0x14b0 fs/ext4/mballoc.c:6652
 ext4_ext_try_to_merge_up fs/ext4/extents.c:1887 [inline]
 ext4_ext_try_to_merge+0x305/0x320 fs/ext4/extents.c:1914
 ext4_swap_extents+0xbf4/0xf00 fs/ext4/extents.c:5791
 move_extent_per_page+0xf44/0x16e0 fs/ext4/move_extent.c:375
 ext4_move_extents+0x57d/0x6b0 fs/ext4/move_extent.c:686
 __ext4_ioctl fs/ext4/ioctl.c:1365 [inline]
 ext4_ioctl+0x1d88/0x2e50 fs/ext4/ioctl.c:1619
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:892
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:892
 x64_sys_call+0x1690/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c2ba28 of 8 bytes by task 22393 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1521
 smp_call_function_many_cond+0x305/0xbb0 kernel/smp.c:838
 on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1052
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1530
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9b/0x1a0 block/bdev.c:670
 blkdev_put_whole block/bdev.c:677 [inline]
 bdev_release+0x2f9/0x420 block/bdev.c:1102
 blkdev_release+0x15/0x20 block/fops.c:660
 __fput+0x2ac/0x640 fs/file_table.c:464
 ____fput+0x1c/0x30 fs/file_table.c:492
 task_work_run+0x13a/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88813e500bc8 -> 0xffff88813e6b2af8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22393 Comm: syz-executor Not tainted 6.14.0-rc5-syzkaller-00109-g0f52fd4f67c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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