On Thu, Apr 9, 2020 at 10:29 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > > On 4/8/20 8:50 PM, Dmitry Kadashev wrote: > > 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. > > Thanks for testing! Can I ask if this is going to be merged into 5.6? Since it's a bug (important enough from my perspective) in existing logic. Thanks. -- Dmitry
