Add support for name_to_handle_at(2) to io_uring.
Like openat*(), this tries to do a non-blocking lookup first and resorts
to async lookup when that fails.
This uses sqe->addr for the path, ->addr2 for the file handle which is
filled in by the kernel, and ->addr3 for the mouint_id which is filled
in by the kernel.
Signed-off-by: Thomas Bertschinger <tahbertschinger@xxxxxxxxx>
---
include/uapi/linux/io_uring.h | 2 ++
io_uring/opdef.c | 11 +++++++++
io_uring/openclose.c | 45 +++++++++++++++++++++++++++++++++++
io_uring/openclose.h | 5 ++++
4 files changed, 63 insertions(+)
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 6957dc539d83..a4aa83ad9527 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -74,6 +74,7 @@ struct io_uring_sqe {
__u32 install_fd_flags;
__u32 nop_flags;
__u32 pipe_flags;
+ __u32 name_to_handle_flags;
};
__u64 user_data; /* data to be passed back at completion time */
/* pack this to avoid bogus arm OABI complaints */
@@ -289,6 +290,7 @@ enum io_uring_op {
IORING_OP_READV_FIXED,
IORING_OP_WRITEV_FIXED,
IORING_OP_PIPE,
+ IORING_OP_NAME_TO_HANDLE_AT,
/* this goes last, obviously */
IORING_OP_LAST,
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 9568785810d9..76306c9e0ecd 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -574,6 +574,14 @@ const struct io_issue_def io_issue_defs[] = {
.prep = io_pipe_prep,
.issue = io_pipe,
},
+ [IORING_OP_NAME_TO_HANDLE_AT] = {
+#if defined(CONFIG_FHANDLE)
+ .prep = io_name_to_handle_at_prep,
+ .issue = io_name_to_handle_at,
+#else
+ .prep = io_eopnotsupp_prep,
+#endif
+ },
};
const struct io_cold_def io_cold_defs[] = {
@@ -824,6 +832,9 @@ const struct io_cold_def io_cold_defs[] = {
[IORING_OP_PIPE] = {
.name = "PIPE",
},
+ [IORING_OP_NAME_TO_HANDLE_AT] = {
+ .name = "NAME_TO_HANDLE_AT",
+ },
};
const char *io_uring_get_opcode(u8 opcode)
diff --git a/io_uring/openclose.c b/io_uring/openclose.c
index d70700e5cef8..884a66e56643 100644
--- a/io_uring/openclose.c
+++ b/io_uring/openclose.c
@@ -27,6 +27,15 @@ struct io_open {
unsigned long nofile;
};
+struct io_name_to_handle {
+ struct file *file;
+ int dfd;
+ int flags;
+ struct file_handle __user *ufh;
+ char __user *path;
+ void __user *mount_id;
+};
+
struct io_close {
struct file *file;
int fd;
@@ -187,6 +196,42 @@ void io_open_cleanup(struct io_kiocb *req)
putname(open->filename);
}
+#if defined(CONFIG_FHANDLE)
+int io_name_to_handle_at_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_name_to_handle *nh = io_kiocb_to_cmd(req, struct io_name_to_handle);
+
+ nh->dfd = READ_ONCE(sqe->fd);
+ nh->flags = READ_ONCE(sqe->name_to_handle_flags);
+ nh->path = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ nh->ufh = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ nh->mount_id = u64_to_user_ptr(READ_ONCE(sqe->addr3));
+
+ return 0;
+}
+
+int io_name_to_handle_at(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_name_to_handle *nh = io_kiocb_to_cmd(req, struct io_name_to_handle);
+ int lookup_flags = 0;
+ long ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ lookup_flags = LOOKUP_CACHED;
+
+ ret = do_sys_name_to_handle_at(nh->dfd, nh->path, nh->ufh, nh->mount_id,
+ nh->flags, lookup_flags);
+
+ if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
+ return -EAGAIN;
+
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ return IOU_COMPLETE;
+}
+#endif /* CONFIG_FHANDLE */
+
int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags,
unsigned int offset)
{
diff --git a/io_uring/openclose.h b/io_uring/openclose.h
index 4ca2a9935abc..2fc1c8d35d0b 100644
--- a/io_uring/openclose.h
+++ b/io_uring/openclose.h
@@ -10,6 +10,11 @@ void io_open_cleanup(struct io_kiocb *req);
int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_openat2(struct io_kiocb *req, unsigned int issue_flags);
+#if defined(CONFIG_FHANDLE)
+int io_name_to_handle_at_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+int io_name_to_handle_at(struct io_kiocb *req, unsigned int issue_flags);
+#endif /* CONFIG_FHANDLE */
+
int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_close(struct io_kiocb *req, unsigned int issue_flags);
--
2.51.0
