diff options
| author | Josh Triplett <josh@joshtriplett.org> | 2023-02-14 16:42:22 -0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-02-16 06:09:30 -0700 |
| commit | 7d3fd88d61a41016da01889f076fd1c60c7298fc (patch) | |
| tree | 6d585bf491aa17b8c19876a73c4df07c0476f416 /io_uring | |
| parent | fbe870a72fd1ddc5e08c23764e23e5766f54aa87 (diff) | |
| download | linux-pm-7d3fd88d61a41016da01889f076fd1c60c7298fc.tar.gz | |
io_uring: Support calling io_uring_register with a registered ring fd
Add a new flag IORING_REGISTER_USE_REGISTERED_RING (set via the high bit
of the opcode) to treat the fd as a registered index rather than a file
descriptor.
This makes it possible for a library to open an io_uring, register the
ring fd, close the ring fd, and subsequently use the ring entirely via
registered index.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/f2396369e638284586b069dbddffb8c992afba95.1676419314.git.josh@joshtriplett.org
[axboe: remove extra high bit clear]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/io_uring.c | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 0e42160a3051d4..3b915deb4d08f4 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3785,7 +3785,7 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p, IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED | IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS | IORING_FEAT_RSRC_TAGS | IORING_FEAT_CQE_SKIP | - IORING_FEAT_LINKED_FILE; + IORING_FEAT_LINKED_FILE | IORING_FEAT_REG_REG_RING; if (copy_to_user(params, p, sizeof(*p))) { ret = -EFAULT; @@ -4306,17 +4306,36 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, struct io_ring_ctx *ctx; long ret = -EBADF; struct fd f; + bool use_registered_ring; + + use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING); + opcode &= ~IORING_REGISTER_USE_REGISTERED_RING; if (opcode >= IORING_REGISTER_LAST) return -EINVAL; - f = fdget(fd); - if (!f.file) - return -EBADF; + if (use_registered_ring) { + /* + * Ring fd has been registered via IORING_REGISTER_RING_FDS, we + * need only dereference our task private array to find it. + */ + struct io_uring_task *tctx = current->io_uring; - ret = -EOPNOTSUPP; - if (!io_is_uring_fops(f.file)) - goto out_fput; + if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) + return -EINVAL; + fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); + f.file = tctx->registered_rings[fd]; + f.flags = 0; + if (unlikely(!f.file)) + return -EBADF; + } else { + f = fdget(fd); + if (unlikely(!f.file)) + return -EBADF; + ret = -EOPNOTSUPP; + if (!io_is_uring_fops(f.file)) + goto out_fput; + } ctx = f.file->private_data; |