This adds support for open_by_handle_at(2) to io_uring.
Non-blocking open by handle is not yet supported, so this always runs in
async context.
Signed-off-by: Thomas Bertschinger <tahbertschinger@xxxxxxxxx>
---
include/uapi/linux/io_uring.h | 1 +
io_uring/opdef.c | 7 ++++
io_uring/openclose.c | 64 ++++++++++++++++++++++++++++++++++-
io_uring/openclose.h | 2 ++
4 files changed, 73 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 596bae788b48..946da13e1454 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -290,6 +290,7 @@ enum io_uring_op {
IORING_OP_WRITEV_FIXED,
IORING_OP_PIPE,
IORING_OP_NAME_TO_HANDLE_AT,
+ IORING_OP_OPEN_BY_HANDLE_AT,
/* this goes last, obviously */
IORING_OP_LAST,
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index ff2672bbd583..e2e0f4ed0d9d 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -578,6 +578,10 @@ const struct io_issue_def io_issue_defs[] = {
.prep = io_name_to_handle_at_prep,
.issue = io_name_to_handle_at,
},
+ [IORING_OP_OPEN_BY_HANDLE_AT] = {
+ .prep = io_open_by_handle_at_prep,
+ .issue = io_open_by_handle_at,
+ },
};
const struct io_cold_def io_cold_defs[] = {
@@ -831,6 +835,9 @@ const struct io_cold_def io_cold_defs[] = {
[IORING_OP_NAME_TO_HANDLE_AT] = {
.name = "NAME_TO_HANDLE_AT",
},
+ [IORING_OP_OPEN_BY_HANDLE_AT] = {
+ .name = "OPEN_BY_HANDLE_AT",
+ }
};
const char *io_uring_get_opcode(u8 opcode)
diff --git a/io_uring/openclose.c b/io_uring/openclose.c
index 8be061783207..5be17d7a46e0 100644
--- a/io_uring/openclose.c
+++ b/io_uring/openclose.c
@@ -22,7 +22,13 @@ struct io_open {
struct file *file;
int dfd;
u32 file_slot;
- struct filename *filename;
+ union {
+ /* For openat(), openat2() */
+ struct filename *filename;
+
+ /* For open_by_handle_at() */
+ struct file_handle __user *ufh;
+ };
struct open_how how;
unsigned long nofile;
};
@@ -244,6 +250,62 @@ int io_name_to_handle_at(struct io_kiocb *req, unsigned int issue_flags)
return IOU_COMPLETE;
}
+int io_open_by_handle_at_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
+ u64 flags;
+
+ flags = READ_ONCE(sqe->open_flags);
+ open->how = build_open_how(flags, 0);
+ open->ufh = u64_to_user_ptr(READ_ONCE(sqe->addr));
+
+ __io_open_prep(req, sqe);
+
+ return 0;
+}
+
+int io_open_by_handle_at(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_open *open = io_kiocb_to_cmd(req, struct io_open);
+ struct file *file;
+ bool fixed = !!open->file_slot;
+ int ret;
+
+ /*
+ * Always try again if we aren't supposed to block, because there is no
+ * way of preventing the FS implementation from blocking.
+ */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ if (!fixed) {
+ ret = __get_unused_fd_flags(open->how.flags, open->nofile);
+ if (ret < 0)
+ goto err;
+ }
+
+ file = __do_handle_open(open->dfd, open->ufh, open->how.flags);
+
+ if (IS_ERR(file)) {
+ if (!fixed)
+ put_unused_fd(ret);
+ ret = PTR_ERR(file);
+ goto err;
+ }
+
+ if (!fixed)
+ fd_install(ret, file);
+ else
+ ret = io_fixed_fd_install(req, issue_flags, file,
+ open->file_slot);
+
+err:
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ return IOU_COMPLETE;
+}
+
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 3d1096abffac..a6304fa856bf 100644
--- a/io_uring/openclose.h
+++ b/io_uring/openclose.h
@@ -12,6 +12,8 @@ int io_openat2(struct io_kiocb *req, unsigned int issue_flags);
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);
+int io_open_by_handle_at_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+int io_open_by_handle_at(struct io_kiocb *req, unsigned int issue_flags);
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);
--
2.50.1
