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> > Only the data race syzbot reports, "KCSAN: data-race in fat16_ent_put / > fat_mirror_bhs": fat_mirror_bhs() copies a FAT block to the backup FAT > while another task updates an entry in that block. I have not found any > effect on disk. fat_mirror_bhs() holds the backup buffer's lock across > the copy, and every writer mirrors the block again after its own update, > so a copy that caught an entry mid-update is replaced by that writer's > copy. The commit message should have said so, and the patch also lacked > my Signed-off-by: it went out before it was ready, sorry. > > That leaves two ways to deal with the report. Would you prefer marking > the copy as an intended race, data_race() around the memcpy() with a > comment on why it is harmless? Or the locking in this patch, which > holds fat_lock across fat_sync_bhs() for synchronous inodes and so > makes other allocations wait for that I/O? I think former. And Actually I explained a few times for similar issues in past, I didn't add the comment though. Thanks. -- OGAWA Hirofumi