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. > > > Also, forgot to mention, this is on x86_64, not sure if O_LARGEFILE is > > necessary to do 2G+ files there? > > Internally, yes. > > -- > Jens Axboe > -- Dmitry
