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BUG: KCSAN: data-race in ext4_mark_iloc_dirty / generic_update_time

read to 0xffff8880bb4e53d0 of 8 bytes by task 14840 on cpu 1:
 ext4_do_update_inode fs/ext4/inode.c:5265 [inline]
 ext4_mark_iloc_dirty+0x44a/0x1580 fs/ext4/inode.c:5876
 ext4_mark_inode_dirty+0xe9/0x420 fs/ext4/inode.c:6055
 ext4_dirty_inode+0x86/0xb0 fs/ext4/inode.c:6086
 __mark_inode_dirty+0x5d4/0x940 fs/fs-writeback.c:2255
 mark_inode_dirty_sync include/linux/fs.h:2170 [inline]
 dquot_claim_block include/linux/quotaops.h:355 [inline]
 ext4_da_update_reserve_space+0x32a/0x3a0 fs/ext4/inode.c:378
 ext4_ext_map_blocks+0x1e57/0x2330 fs/ext4/extents.c:4520
 ext4_map_blocks+0x23a/0xfa0 fs/ext4/inode.c:640
 mpage_map_one_extent fs/ext4/inode.c:2468 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2517 [inline]
 ext4_writepages+0x136e/0x2300 fs/ext4/inode.c:2869
 do_writepages+0x6b/0x170 mm/page-writeback.c:2344
 __filemap_fdatawrite_range+0x1c5/0x230 mm/filemap.c:420
 filemap_write_and_wait_range mm/filemap.c:680 [inline]
 filemap_write_and_wait_range+0xb1/0x150 mm/filemap.c:674
 generic_file_read_iter+0x1015/0x1440 mm/filemap.c:2293
 ext4_file_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0xfa/0x240 fs/ext4/file.c:65
 call_read_iter include/linux/fs.h:1889 [inline]
 generic_file_splice_read+0x35c/0x500 fs/splice.c:307

write to 0xffff8880bb4e53d0 of 16 bytes by task 14835 on cpu 0:
 generic_update_time+0x109/0x270 fs/inode.c:1660
 update_time fs/inode.c:1683 [inline]
 file_update_time+0x237/0x300 fs/inode.c:1898
 __generic_file_write_iter+0x132/0x380 mm/filemap.c:3383
 ext4_file_write_iter+0x1bd/0xa00 fs/ext4/file.c:268
 call_write_iter include/linux/fs.h:1895 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:951
 vfs_iter_write+0x5c/0x80 fs/read_write.c:983
 iter_file_splice_write+0x4c0/0x7f0 fs/splice.c:746
 do_splice_from fs/splice.c:848 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1020
 splice_direct_to_actor+0x215/0x510 fs/splice.c:975
 do_splice_direct+0x161/0x1e0 fs/splice.c:1063
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1511

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14835 Comm: syz-executor.2 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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