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| author | Jens Axboe <axboe@kernel.dk> | 2023-12-08 06:06:02 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-12-12 17:42:57 +0300 |
| commit | dc18b89ab113e9c6c7a529316ddf7029fb55132d (patch) | |
| tree | 682c2a5f7e58b4af465e4e59fba5bf417420e2cf /io_uring/opdef.c | |
| parent | 055c15626a45b1ebc9f2f34981e705e1af171236 (diff) | |
| download | linux-dc18b89ab113e9c6c7a529316ddf7029fb55132d.tar.xz | |
io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL
io_uring can currently open/close regular files or fixed/direct
descriptors. Or you can instantiate a fixed descriptor from a regular
one, and then close the regular descriptor. But you currently can't turn
a purely fixed/direct descriptor into a regular file descriptor.
IORING_OP_FIXED_FD_INSTALL adds support for installing a direct
descriptor into the normal file table, just like receiving a file
descriptor or opening a new file would do. This is all nicely abstracted
into receive_fd(), and hence adding support for this is truly trivial.
Since direct descriptors are only usable within io_uring itself, it can
be useful to turn them into real file descriptors if they ever need to
be accessed via normal syscalls. This can either be a transitory thing,
or just a permanent transition for a given direct descriptor.
By default, new fds are installed with O_CLOEXEC set. The application
can disable O_CLOEXEC by setting IORING_FIXED_FD_NO_CLOEXEC in the
sqe->install_fd_flags member.
Suggested-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/opdef.c')
| -rw-r--r-- | io_uring/opdef.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/io_uring/opdef.c b/io_uring/opdef.c index 799db44283c7..6705634e5f52 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -469,6 +469,12 @@ const struct io_issue_def io_issue_defs[] = { .prep = io_eopnotsupp_prep, #endif }, + [IORING_OP_FIXED_FD_INSTALL] = { + .needs_file = 1, + .audit_skip = 1, + .prep = io_install_fixed_fd_prep, + .issue = io_install_fixed_fd, + }, }; const struct io_cold_def io_cold_defs[] = { @@ -704,6 +710,9 @@ const struct io_cold_def io_cold_defs[] = { [IORING_OP_FUTEX_WAITV] = { .name = "FUTEX_WAITV", }, + [IORING_OP_FIXED_FD_INSTALL] = { + .name = "FIXED_FD_INSTALL", + }, }; const char *io_uring_get_opcode(u8 opcode) |