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BUG: KCSAN: data-race in ext4_ext_insert_extent / ext4_mark_iloc_dirty

write to 0xffff88811da064d0 of 4 bytes by task 15347 on cpu 0:
 ext4_ext_store_pblock fs/ext4/ext4_extents.h:255 [inline]
 ext4_ext_insert_extent+0x1235/0x2bc0 fs/ext4/extents.c:2116
 ext4_ext_map_blocks+0x167d/0x1f00 fs/ext4/extents.c:4262
 ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638
 mpage_map_one_extent+0x10d/0x360 fs/ext4/inode.c:2395
 mpage_map_and_submit_extent fs/ext4/inode.c:2448 [inline]
 ext4_writepages+0xc1a/0x1d10 fs/ext4/inode.c:2800
 do_writepages+0x7b/0x150 mm/page-writeback.c:2360
 __filemap_fdatawrite_range mm/filemap.c:413 [inline]
 filemap_write_and_wait_range+0x20a/0x390 mm/filemap.c:686
 __iomap_dio_rw+0x4f0/0xa40 fs/iomap/direct-io.c:533
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649
 ext4_dio_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0x21a/0x290 fs/ext4/file.c:128
 call_read_iter include/linux/fs.h:2108 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88811da064d0 of 4 bytes by task 15344 on cpu 1:
 ext4_do_update_inode fs/ext4/inode.c:5109 [inline]
 ext4_mark_iloc_dirty+0xd85/0x1750 fs/ext4/inode.c:5724
 __ext4_mark_inode_dirty+0x4db/0x5b0 fs/ext4/inode.c:5918
 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5947
 __mark_inode_dirty+0x77/0x6c0 fs/fs-writeback.c:2412
 generic_update_time fs/inode.c:1772 [inline]
 update_time fs/inode.c:1785 [inline]
 touch_atime+0x170/0x240 fs/inode.c:1856
 file_accessed include/linux/fs.h:2456 [inline]
 filemap_read+0x11c9/0x1230 mm/filemap.c:2622
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
 ext4_file_read_iter+0x1db/0x290 fs/ext4/file.c:73
 call_read_iter include/linux/fs.h:2108 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00021cb0 -> 0x00021cc0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15344 Comm: syz-executor.3 Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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