On Wed, Apr 8, 2020 at 11:26 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > > On 4/8/20 9:12 AM, Dmitry Kadashev wrote: > > On Wed, Apr 8, 2020 at 10:49 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > >> > >> On 4/8/20 8:41 AM, Dmitry Kadashev wrote: > >>> On Wed, Apr 8, 2020 at 10:36 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > >>>> > >>>> On 4/8/20 8:30 AM, Dmitry Kadashev wrote: > >>>>> On Wed, Apr 8, 2020 at 10:19 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > >>>>>> > >>>>>> On 4/8/20 7:51 AM, Dmitry Kadashev wrote: > >>>>>>> Hi, > >>>>>>> > >>>>>>> io_uring's openat seems to produce FDs that are incompatible with > >>>>>>> large files (>2GB). If a file (smaller than 2GB) is opened using > >>>>>>> io_uring's openat then writes -- both using io_uring and just sync > >>>>>>> pwrite() -- past that threshold fail with EFBIG. If such a file is > >>>>>>> opened with sync openat, then both io_uring's writes and sync writes > >>>>>>> succeed. And if the file is larger than 2GB then io_uring's openat > >>>>>>> fails right away, while the sync one works. > >>>>>>> > >>>>>>> Kernel versions: 5.6.0-rc2, 5.6.0. > >>>>>>> > >>>>>>> A couple of reproducers attached, one demos successful open with > >>>>>>> failed writes afterwards, and another failing open (in comparison with > >>>>>>> sync calls). > >>>>>>> > >>>>>>> The output of the former one for example: > >>>>>>> > >>>>>>> *** sync openat > >>>>>>> openat succeeded > >>>>>>> sync write at offset 0 > >>>>>>> write succeeded > >>>>>>> sync write at offset 4294967296 > >>>>>>> write succeeded > >>>>>>> > >>>>>>> *** sync openat > >>>>>>> openat succeeded > >>>>>>> io_uring write at offset 0 > >>>>>>> write succeeded > >>>>>>> io_uring write at offset 4294967296 > >>>>>>> write succeeded > >>>>>>> > >>>>>>> *** io_uring openat > >>>>>>> openat succeeded > >>>>>>> sync write at offset 0 > >>>>>>> write succeeded > >>>>>>> sync write at offset 4294967296 > >>>>>>> write failed: File too large > >>>>>>> > >>>>>>> *** io_uring openat > >>>>>>> openat succeeded > >>>>>>> io_uring write at offset 0 > >>>>>>> write succeeded > >>>>>>> io_uring write at offset 4294967296 > >>>>>>> write failed: File too large > >>>>>> > >>>>>> Can you try with this one? Seems like only openat2 gets it set, > >>>>>> not openat... > >>>>> > >>>>> I've tried specifying O_LARGEFILE explicitly, that did not change the > >>>>> behavior. Is this good enough? Much faster for me to check this way > >>>>> that rebuilding the kernel. But if necessary I can do that. > >>>> > >>>> Not sure O_LARGEFILE settings is going to do it for x86-64, the patch > >>>> should fix it though. Might have worked on 32-bit, though. > >>> > >>> OK, will test. > >> > >> Great, thanks. FWIW, tested here, and it works for me. > > > > Great, will post results tomorrow. > > Thanks! With the patch applied it works perfectly, thanks. > > >> Any objection to adding your test cases to the liburing regression > >> suite? > > > > Feel free to! > > Great, done! > -- Dmitry
