[PATCH v3 3/3] io_uring: add support for getdents64

Stefan Roesch
2021-11-25T23:28:09Z

This adds support for getdents64 to io_uring.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 52 +++++++++++++++++++++++++++++++++++
include/uapi/linux/io_uring.h | 1 +
2 files changed, 53 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 08b1b3de9b3f..8fdff4745742 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -691,6 +691,13 @@ struct io_hardlink {
int flags;
};

+struct io_getdents {
+ struct file *file;
+ struct linux_dirent64 __user *dirent;
+ unsigned int count;
+ loff_t pos;
+};
+
struct io_async_connect {
struct sockaddr_storage address;
};
@@ -856,6 +863,7 @@ struct io_kiocb {
struct io_mkdir mkdir;
struct io_symlink symlink;
struct io_hardlink hardlink;
+ struct io_getdents getdents;
};

u8 opcode;
@@ -1105,6 +1113,9 @@ static const struct io_op_def io_op_defs[] = {
[IORING_OP_MKDIRAT] = {},
[IORING_OP_SYMLINKAT] = {},
[IORING_OP_LINKAT] = {},
+ [IORING_OP_GETDENTS] = {
+ .needs_file = 1,
+ },
};

/* requests with any of those set should undergo io_disarm_next() */
@@ -3971,6 +3982,42 @@ static int io_linkat(struct io_kiocb *req, unsigned int issue_flags)
return 0;
}

+static int io_getdents_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_getdents *getdents = &req->getdents;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->rw_flags || sqe->buf_index)
+ return -EINVAL;
+
+ getdents->pos = READ_ONCE(sqe->off);
+ getdents->dirent = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ getdents->count = READ_ONCE(sqe->len);
+
+ return 0;
+}
+
+static int io_getdents(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_getdents *getdents = &req->getdents;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = vfs_getdents(req->file, getdents->dirent, getdents->count, getdents->pos);
+ if (ret < 0) {
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ req_set_fail(req);
+ }
+
+ io_req_complete(req, ret);
+ return 0;
+}
+
static int io_shutdown_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
@@ -6486,6 +6533,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return io_symlinkat_prep(req, sqe);
case IORING_OP_LINKAT:
return io_linkat_prep(req, sqe);
+ case IORING_OP_GETDENTS:
+ return io_getdents_prep(req, sqe);
}

printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -6771,6 +6820,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
case IORING_OP_LINKAT:
ret = io_linkat(req, issue_flags);
break;
+ case IORING_OP_GETDENTS:
+ ret = io_getdents(req, issue_flags);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 787f491f0d2a..57dc88db5793 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -143,6 +143,7 @@ enum {
IORING_OP_MKDIRAT,
IORING_OP_SYMLINKAT,
IORING_OP_LINKAT,
+ IORING_OP_GETDENTS,

/* this goes last, obviously */
IORING_OP_LAST,
--
2.30.2