==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode

read-write to 0xffff8881005f1700 of 8 bytes by task 14919 on cpu 0:
 __writeback_single_inode+0x201/0x870 fs/fs-writeback.c:1686
 writeback_sb_inodes+0x4de/0xaa0 fs/fs-writeback.c:1941
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:2012
 wb_writeback+0x264/0x6f0 fs/fs-writeback.c:2119
 wb_check_background_flush fs/fs-writeback.c:2189 [inline]
 wb_do_writeback fs/fs-writeback.c:2277 [inline]
 wb_workfn+0x67f/0x940 fs/fs-writeback.c:2304
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3348
 worker_thread+0x526/0x730 kernel/workqueue.c:3429
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff8881005f1700 of 8 bytes by task 10 on cpu 1:
 __mark_inode_dirty+0x19f/0x7e0 fs/fs-writeback.c:2499
 mark_buffer_dirty+0x165/0x250 fs/buffer.c:1204
 __ext4_handle_dirty_metadata+0x1fa/0x470 fs/ext4/ext4_jbd2.c:384
 ext4_do_update_inode fs/ext4/inode.c:5091 [inline]
 ext4_mark_iloc_dirty+0xaa4/0xe10 fs/ext4/inode.c:5709
 __ext4_mark_inode_dirty+0x314/0x440 fs/ext4/inode.c:5913
 __ext4_ext_dirty+0xbf/0x130 fs/ext4/extents.c:202
 ext4_convert_unwritten_extents_endio fs/ext4/extents.c:3747 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3872 [inline]
 ext4_ext_map_blocks+0x1ee6/0x33b0 fs/ext4/extents.c:4208
 ext4_map_blocks+0x72a/0xf50 fs/ext4/inode.c:623
 ext4_convert_unwritten_extents+0x16c/0x2c0 fs/ext4/extents.c:4845
 ext4_convert_unwritten_io_end_vec+0xa2/0x110 fs/ext4/extents.c:4884
 ext4_end_io_end fs/ext4/page-io.c:186 [inline]
 ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline]
 ext4_end_io_rsv_work+0x17d/0x370 fs/ext4/page-io.c:273
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3348
 worker_thread+0x526/0x730 kernel/workqueue.c:3429
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x0000000000020084 -> 0x0000000000000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10 Comm: kworker/u8:0 Tainted: G        W          6.9.0-rc6-syzkaller-00113-g49a73b1652c5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
==================================================================