io_uring: add support for IORING_OP_OPEN_BY_HANDLE
Add support for opening files with a struct file_handle, similarly to
what open_by_handle_at() supports.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index cfd17e3..b00950e 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -289,6 +289,7 @@ enum io_uring_op {
IORING_OP_READV_FIXED,
IORING_OP_WRITEV_FIXED,
IORING_OP_PIPE,
+ IORING_OP_OPEN_BY_HANDLE,
/* this goes last, obviously */
IORING_OP_LAST,
@@ -451,6 +452,13 @@ enum io_uring_msg_ring_flags {
#define IORING_NOP_FIXED_BUFFER (1U << 3)
/*
+ * IORING_OP_OPEN_BY_HANDLE flags
+ *
+ * IORING_OPEN_HANDLE_FIXED Use a fixed/registered file
+ */
+#define IORING_OPEN_HANDLE_FIXED (1U << 0)
+
+/*
* IO completion data structure (Completion Queue Entry)
*/
struct io_uring_cqe {
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 6e0882b..72180e0 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -573,6 +573,16 @@ const struct io_issue_def io_issue_defs[] = {
.prep = io_pipe_prep,
.issue = io_pipe,
},
+ [IORING_OP_OPEN_BY_HANDLE] = {
+ .ioprio = 1,
+ .async_size = sizeof(struct io_open_handle_async),
+#if defined(CONFIG_FHANDLE)
+ .prep = io_open_by_handle_prep,
+ .issue = io_open_by_handle,
+#else
+ .prep = io_eopnotsupp_prep,
+#endif
+ },
};
const struct io_cold_def io_cold_defs[] = {
@@ -822,6 +832,9 @@ const struct io_cold_def io_cold_defs[] = {
[IORING_OP_PIPE] = {
.name = "PIPE",
},
+ [IORING_OP_OPEN_BY_HANDLE] = {
+ .name = "OPEN_BY_HANDLE",
+ },
};
const char *io_uring_get_opcode(u8 opcode)
diff --git a/io_uring/openclose.c b/io_uring/openclose.c
index 83e36ad..c3512a4 100644
--- a/io_uring/openclose.c
+++ b/io_uring/openclose.c
@@ -8,6 +8,7 @@
#include <linux/namei.h>
#include <linux/pipe_fs_i.h>
#include <linux/watch_queue.h>
+#include <linux/fs_struct.h>
#include <linux/io_uring.h>
#include <uapi/linux/io_uring.h>
@@ -38,6 +39,15 @@ struct io_fixed_install {
unsigned int o_flags;
};
+struct io_open_handle {
+ struct file *file;
+ int dirfd;
+ int open_flags;
+ int flags;
+ u32 file_slot;
+ struct handle_to_path_ctx ctx;
+};
+
static bool io_openat_force_async(struct io_open *open)
{
/*
@@ -435,3 +445,145 @@ int io_pipe(struct io_kiocb *req, unsigned int issue_flags)
fput(files[1]);
return ret;
}
+
+#if defined(CONFIG_FHANDLE)
+
+int io_open_by_handle_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_open_handle *h = io_kiocb_to_cmd(req, struct io_open_handle);
+ struct io_open_handle_async *ah;
+ struct file_handle __user *uh;
+
+ if (sqe->off || sqe->len)
+ return -EINVAL;
+ if (req->flags & REQ_F_FIXED_FILE)
+ return -EBADF;
+
+ memset(&h->ctx, 0, sizeof(h->ctx));
+
+ h->dirfd = READ_ONCE(sqe->fd);
+ h->open_flags = READ_ONCE(sqe->open_flags);
+ h->flags = READ_ONCE(sqe->ioprio);
+ if (h->flags & ~IORING_OPEN_HANDLE_FIXED)
+ return -EINVAL;
+
+ h->file_slot = READ_ONCE(sqe->file_index);
+ if (h->file_slot && !(h->flags & IORING_OPEN_HANDLE_FIXED))
+ return -EINVAL;
+
+ ah = io_uring_alloc_async_data(NULL, req);
+ if (!ah)
+ return -ENOMEM;
+
+ uh = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ if (get_user(ah->handle.handle_bytes, &uh->handle_bytes) ||
+ get_user(ah->handle.handle_type, &uh->handle_type))
+ return -EFAULT;
+
+ if (!ah->handle.handle_bytes || ah->handle.handle_bytes > MAX_HANDLE_SZ)
+ return -EINVAL;
+ if (ah->handle.handle_type < 0 ||
+ FILEID_USER_FLAGS(ah->handle.handle_type) & ~FILEID_VALID_USER_FLAGS)
+ return -EINVAL;
+
+ if (copy_from_user(&ah->handle.f_handle, &uh->f_handle, ah->handle.handle_bytes))
+ return -EFAULT;
+
+ if (ah->handle.handle_type & FILEID_IS_CONNECTABLE) {
+ h->ctx.fh_flags |= EXPORT_FH_CONNECTABLE;
+ h->ctx.flags |= HANDLE_CHECK_SUBTREE;
+ }
+ if (ah->handle.handle_type & FILEID_IS_DIR)
+ h->ctx.fh_flags |= EXPORT_FH_DIR_ONLY;
+ ah->handle.handle_type &= ~FILEID_USER_FLAGS_MASK;
+ return 0;
+}
+
+static int __io_open_by_handle(struct io_kiocb *req, unsigned int issue_flags,
+ const struct export_operations *eops)
+{
+ struct io_open_handle *h = io_kiocb_to_cmd(req, struct io_open_handle);
+ struct io_open_handle_async *ah = req->async_data;
+ struct path path __free(path_put) = { };
+ struct file *file;
+ int ret, fd;
+
+ ret = do_handle_to_path(&ah->handle, &path, &h->ctx);
+ path_put(&h->ctx.root);
+ if (ret < 0)
+ return ret;
+
+ if (!(h->flags & IORING_OPEN_HANDLE_FIXED)) {
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+ }
+
+ if (eops->open) {
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ file = ERR_PTR(-EAGAIN);
+ goto err;
+ }
+ file = eops->open(&path, h->open_flags);
+ } else {
+ struct open_flags op;
+ struct open_how how = build_open_how(h->open_flags, 0);
+
+ ret = build_open_flags(&how, &op);
+ if (ret)
+ return ret;
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ op.lookup_flags |= LOOKUP_CACHED;
+ op.open_flag |= O_NONBLOCK;
+ }
+ file = do_file_open_root(&path, "", &op);
+ }
+ if (IS_ERR(file)) {
+err:
+ if (!(h->flags & IORING_OPEN_HANDLE_FIXED))
+ put_unused_fd(fd);
+ return PTR_ERR(file);
+ }
+
+ if (!(h->flags & IORING_OPEN_HANDLE_FIXED)) {
+ fd_install(fd, file);
+ return fd;
+ }
+
+ return io_fixed_fd_install(req, issue_flags, file, h->file_slot);
+}
+
+int io_open_by_handle(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_open_handle *h = io_kiocb_to_cmd(req, struct io_open_handle);
+ const struct export_operations *eops;
+ int ret;
+
+ ret = get_path_from_fd(h->dirfd, &h->ctx.root);
+ if (ret < 0)
+ goto err;
+
+ eops = h->ctx.root.mnt->mnt_sb->s_export_op;
+ if (eops && eops->permission)
+ ret = eops->permission(&h->ctx, h->open_flags);
+ else
+ ret = may_decode_fh(&h->ctx, h->open_flags);
+ if (ret) {
+ path_put(&h->ctx.root);
+ goto err;
+ }
+
+ ret = __io_open_by_handle(req, issue_flags, eops);
+ io_req_set_res(req, ret, 0);
+ if (ret < 0) {
+err:
+ req_set_fail(req);
+ return ret;
+ }
+
+ kfree(req->async_data);
+ req->async_data = NULL;
+ req->flags &= ~REQ_F_ASYNC_DATA;
+ return IOU_COMPLETE;
+}
+#endif /* CONFIG_FHANDLE */
diff --git a/io_uring/openclose.h b/io_uring/openclose.h
index 4ca2a99..97a0958 100644
--- a/io_uring/openclose.h
+++ b/io_uring/openclose.h
@@ -1,5 +1,16 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/fs.h>
+#include <linux/exportfs.h>
+
+struct io_open_handle_async {
+ union {
+ struct file_handle handle;
+ char pad[sizeof(struct file_handle) +
+ MAX_HANDLE_SZ];
+ };
+};
+
int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags,
unsigned int offset);
@@ -16,5 +27,8 @@ int io_close(struct io_kiocb *req, unsigned int issue_flags);
int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_pipe(struct io_kiocb *req, unsigned int issue_flags);
+int io_open_by_handle_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+int io_open_by_handle(struct io_kiocb *req, unsigned int issue_flags);
+
int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags);
