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BUG: KCSAN: data-race in __writeback_single_inode / xas_set_mark

write to 0xffff88812d64951c of 4 bytes by task 30118 on cpu 1:
 xa_mark_set lib/xarray.c:69 [inline]
 xas_set_mark+0x131/0x140 lib/xarray.c:894
 __folio_start_writeback+0x23f/0x4b0 mm/page-writeback.c:3070
 __mpage_writepage+0xc0a/0xda0 fs/mpage.c:606
 write_cache_pages+0x39b/0x760 mm/page-writeback.c:2473
 mpage_writepages+0x72/0xe0 fs/mpage.c:653
 fat_writepages+0x24/0x30 fs/fat/inode.c:200
 do_writepages+0x1c5/0x340 mm/page-writeback.c:2551
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:390
 __filemap_fdatawrite_range mm/filemap.c:423 [inline]
 file_write_and_wait_range+0xfa/0x190 mm/filemap.c:781
 __generic_file_fsync+0x4c/0x140 fs/libfs.c:1132
 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:2452 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4090
 do_iter_write+0x418/0x700 fs/read_write.c:861
 vfs_iter_write+0x50/0x70 fs/read_write.c:902
 iter_file_splice_write+0x456/0x7d0 fs/splice.c:778
 do_splice_from fs/splice.c:856 [inline]
 direct_splice_actor+0x84/0xa0 fs/splice.c:1022
 splice_direct_to_actor+0x2ee/0x5f0 fs/splice.c:977
 do_splice_direct+0x104/0x180 fs/splice.c:1065
 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 0xffff88812d64951c of 4 bytes by task 30137 on cpu 0:
 xa_marked include/linux/xarray.h:420 [inline]
 mapping_tagged include/linux/fs.h:463 [inline]
 __writeback_single_inode+0x21d/0x860 fs/fs-writeback.c:1651
 writeback_single_inode+0x12f/0x4a0 fs/fs-writeback.c:1721
 sync_inode_metadata+0x56/0x80 fs/fs-writeback.c:2777
 __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:2452 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4090
 do_iter_write+0x418/0x700 fs/read_write.c:861
 vfs_iter_write+0x50/0x70 fs/read_write.c:902
 iter_file_splice_write+0x456/0x7d0 fs/splice.c:778
 do_splice_from fs/splice.c:856 [inline]
 direct_splice_actor+0x84/0xa0 fs/splice.c:1022
 splice_direct_to_actor+0x2ee/0x5f0 fs/splice.c:977
 do_splice_direct+0x104/0x180 fs/splice.c:1065
 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: 0x28000021 -> 0x10000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 30137 Comm: syz-executor.1 Not tainted 6.3.0-rc4-syzkaller-00025-g3a93e40326c8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
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==================================================================
BUG: KCSAN: data-race in __generic_file_fsync / __mark_inode_dirty

write to 0xffff88812d649430 of 8 bytes by task 30118 on cpu 1:
 __mark_inode_dirty+0x250/0x7d0 fs/fs-writeback.c:2452
 fat_update_time+0x28e/0x2c0 fs/fat/misc.c:359
 inode_update_time fs/inode.c:1872 [inline]
 touch_atime+0x180/0x300 fs/inode.c:1945
 file_accessed include/linux/fs.h:2181 [inline]
 filemap_read+0x612/0x680 mm/filemap.c:2762
 generic_file_read_iter+0x76/0x320 mm/filemap.c:2840
 call_read_iter include/linux/fs.h:1845 [inline]
 generic_file_splice_read+0xe3/0x290 fs/splice.c:402
 do_splice_to fs/splice.c:885 [inline]
 splice_direct_to_actor+0x25a/0x5f0 fs/splice.c:956
 do_splice_direct+0x104/0x180 fs/splice.c:1065
 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 0xffff88812d649430 of 8 bytes by task 30137 on cpu 0:
 __generic_file_fsync+0x95/0x140 fs/libfs.c:1138
 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:2452 [inline]
 generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4090
 do_iter_write+0x418/0x700 fs/read_write.c:861
 vfs_iter_write+0x50/0x70 fs/read_write.c:902
 iter_file_splice_write+0x456/0x7d0 fs/splice.c:778
 do_splice_from fs/splice.c:856 [inline]
 direct_splice_actor+0x84/0xa0 fs/splice.c:1022
 splice_direct_to_actor+0x2ee/0x5f0 fs/splice.c:977
 do_splice_direct+0x104/0x180 fs/splice.c:1065
 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: 0x0000000000000000 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 30137 Comm: syz-executor.1 Not tainted 6.3.0-rc4-syzkaller-00025-g3a93e40326c8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
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