KCSAN: data-race in __es_find_extent_range / ext4_es_lookup_extent

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: eccc8767 Merge branch 'fixes' of git://git.kernel.org/pub/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10910006500000
kernel config: https://syzkaller.appspot.com/x/.config?x=671e27f23e60a67b
dashboard link: https://syzkaller.appspot.com/bug?extid=ddc9f8c6a385600b6dbb
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [adilger...@dilger.ca linux...@vger.kernel.org linux-...@vger.kernel.org ty...@mit.edu]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ddc9f8...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __es_find_extent_range / ext4_es_lookup_extent

read to 0xffff88801263b948 of 8 bytes by task 12026 on cpu 0:
ext4_es_lookup_extent+0xac/0x500 fs/ext4/extents_status.c:937
ext4_da_map_blocks fs/ext4/inode.c:1705 [inline]
ext4_da_get_block_prep+0x14e/0x9a0 fs/ext4/inode.c:1826
ext4_block_write_begin+0x3f0/0xaa0 fs/ext4/inode.c:1068
ext4_da_write_begin+0x50a/0xaf0 fs/ext4/inode.c:3007
generic_perform_write+0x196/0x3a0 mm/filemap.c:3311
ext4_buffered_write_iter+0x2e5/0x3d0 fs/ext4/file.c:270
ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
call_write_iter include/linux/fs.h:1887 [inline]
do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
do_iter_write+0x112/0x4b0 fs/read_write.c:866
vfs_iter_write+0x4c/0x70 fs/read_write.c:907
iter_file_splice_write+0x42a/0x780 fs/splice.c:686
do_splice_from fs/splice.c:764 [inline]
direct_splice_actor+0x80/0xa0 fs/splice.c:933
splice_direct_to_actor+0x345/0x650 fs/splice.c:888
do_splice_direct+0xf5/0x170 fs/splice.c:976
do_sendfile+0x574/0xb70 fs/read_write.c:1257
__do_sys_sendfile64 fs/read_write.c:1318 [inline]
__se_sys_sendfile64 fs/read_write.c:1304 [inline]
__x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88801263b948 of 8 bytes by task 12028 on cpu 1:
__es_find_extent_range+0x28e/0x330 fs/ext4/extents_status.c:298
ext4_es_find_extent_range+0x8a/0x200 fs/ext4/extents_status.c:320
ext4_ext_put_gap_in_cache fs/ext4/extents.c:2237 [inline]
ext4_ext_map_blocks+0xb96/0x1fc0 fs/ext4/extents.c:4143
ext4_map_blocks+0x1cc/0xfc0 fs/ext4/inode.c:553
ext4_mpage_readpages+0x718/0x1360 fs/ext4/readpage.c:304
ext4_readahead+0x99/0xa0 fs/ext4/inode.c:3252
read_pages+0xa0/0x6e0 mm/readahead.c:130
page_cache_ra_unbounded+0x464/0x4c0 mm/readahead.c:238
ondemand_readahead+0x560/0x780 mm/readahead.c:267
page_cache_sync_ra+0x1ab/0x1c0 mm/readahead.c:577
page_cache_sync_readahead include/linux/pagemap.h:839 [inline]
generic_file_buffered_read+0x38d/0x2110 mm/filemap.c:2227
generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2535
ext4_file_read_iter+0x2d0/0x420 fs/ext4/file.c:74
call_read_iter include/linux/fs.h:1881 [inline]
generic_file_splice_read+0x22a/0x310 fs/splice.c:311
do_splice_to fs/splice.c:788 [inline]
splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
do_splice_direct+0xf5/0x170 fs/splice.c:976
do_sendfile+0x574/0xb70 fs/read_write.c:1257
__do_sys_sendfile64 fs/read_write.c:1318 [inline]
__se_sys_sendfile64 fs/read_write.c:1304 [inline]
__x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12028 Comm: syz-executor.2 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.