On 19/01/2021 01:58, Joseph Qi wrote: >> Hmm, I hastened, for files we need IO_WQ_WORK_FILES, >> +IO_WQ_WORK_BLKCG for same reasons. needs_file would make >> it to grab a struct file, that is wrong. >> Probably worked out because it just grabbed fd=0/stdin. >> > > I think IO_WQ_WORK_FILES can work since it will acquire > files when initialize async cancel request. That the one controlling files in the first place, need_file just happened to grab them submission. > Don't quite understand why we should have IO_WQ_WORK_BLKCG. Because it's set for IORING_OP_CLOSE, and similar situation may happen but with async_cancel from io-wq. Actually, it's even nastier than that, and neither of io_op_def flags would work because for io-wq case you can end up doing close() with different from original files. I'll think how it can be done tomorrow. -- Pavel Begunkov
