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

write to 0xffff88810aeab770 of 8 bytes by task 6359 on cpu 1:
 writeback_single_inode+0x10e/0x4a0 fs/fs-writeback.c:1716
 sync_inode_metadata+0x56/0x80 fs/fs-writeback.c:2775
 __generic_file_fsync+0xf9/0x140 fs/libfs.c:1143
 fat_file_fsync+0x4c/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x10b/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2885 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:3936
 do_iter_write+0x418/0x700 fs/read_write.c:861
 vfs_iter_write+0x50/0x70 fs/read_write.c:902
 iter_file_splice_write+0x42b/0x7b0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x84/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x2ee/0x5f0 fs/splice.c:886
 do_splice_direct+0x104/0x180 fs/splice.c:974
 do_sendfile+0x3b8/0x950 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810aeab770 of 8 bytes by task 6375 on cpu 0:
 __mark_inode_dirty+0x199/0x7d0 fs/fs-writeback.c:2441
 fat_update_time+0x28e/0x2c0 fs/fat/misc.c:359
 inode_update_time fs/inode.c:1871 [inline]
 touch_atime+0x180/0x300 fs/inode.c:1944
 file_accessed include/linux/fs.h:2519 [inline]
 filemap_read+0x14b6/0x1530 mm/filemap.c:2762
 generic_file_read_iter+0x76/0x320 mm/filemap.c:2840
 call_read_iter include/linux/fs.h:2183 [inline]
 generic_file_splice_read+0xe3/0x290 fs/splice.c:309
 do_splice_to fs/splice.c:793 [inline]
 splice_direct_to_actor+0x25a/0x5f0 fs/splice.c:865
 do_splice_direct+0x104/0x180 fs/splice.c:974
 do_sendfile+0x3b8/0x950 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000007 -> 0x0000000000000080

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6375 Comm: syz-executor.1 Not tainted 6.2.0-rc7-syzkaller-00091-g35674e787518-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
==================================================================
==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / __mark_inode_dirty

write to 0xffff88810aeab770 of 8 bytes by task 6359 on cpu 1:
 __mark_inode_dirty+0x250/0x7d0 fs/fs-writeback.c:2450
 mark_buffer_dirty+0x1c9/0x400 fs/buffer.c:1109
 __block_commit_write+0x10a/0x1a0 fs/buffer.c:2065
 block_write_end fs/buffer.c:2144 [inline]
 generic_write_end+0x7f/0x360 fs/buffer.c:2158
 fat_write_end+0x4e/0x160 fs/fat/inode.c:244
 generic_perform_write+0x253/0x3d0 mm/filemap.c:3783
 __generic_file_write_iter+0xe6/0x290 mm/filemap.c:3900
 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:3932
 do_iter_write+0x418/0x700 fs/read_write.c:861
 vfs_iter_write+0x50/0x70 fs/read_write.c:902
 iter_file_splice_write+0x42b/0x7b0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x84/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x2ee/0x5f0 fs/splice.c:886
 do_splice_direct+0x104/0x180 fs/splice.c:974
 do_sendfile+0x3b8/0x950 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810aeab770 of 8 bytes by task 6375 on cpu 0:
 __mark_inode_dirty+0x199/0x7d0 fs/fs-writeback.c:2441
 fat_update_time+0x28e/0x2c0 fs/fat/misc.c:359
 inode_update_time fs/inode.c:1871 [inline]
 touch_atime+0x180/0x300 fs/inode.c:1944
 file_accessed include/linux/fs.h:2519 [inline]
 filemap_read+0x14b6/0x1530 mm/filemap.c:2762
 generic_file_read_iter+0x76/0x320 mm/filemap.c:2840
 call_read_iter include/linux/fs.h:2183 [inline]
 generic_file_splice_read+0xe3/0x290 fs/splice.c:309
 do_splice_to fs/splice.c:793 [inline]
 splice_direct_to_actor+0x25a/0x5f0 fs/splice.c:865
 do_splice_direct+0x104/0x180 fs/splice.c:974
 do_sendfile+0x3b8/0x950 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000800 -> 0x0000000000000007

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6375 Comm: syz-executor.1 Not tainted 6.2.0-rc7-syzkaller-00091-g35674e787518-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
==================================================================