io_uring: add support for getdents64

This adds support for getdents64 to io_uring.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20211221164004.119663-4-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1f2341d87588fe8f1868683b0b840e396aac8db9..c769557866da470f57e14a4b10bf433ea5897655 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -692,6 +692,13 @@ 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;
 };
@@ -857,6 +864,7 @@ struct io_kiocb {
                struct io_mkdir         mkdir;
                struct io_symlink       symlink;
                struct io_hardlink      hardlink;
+               struct io_getdents      getdents;
        };
 
        u8                              opcode;
@@ -1106,6 +1114,9 @@ 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() */
@@ -4037,6 +4048,42 @@ 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)
 {
@@ -6539,6 +6586,8 @@ 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",
@@ -6822,6 +6871,9 @@ 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 787f491f0d2ae0ca62342f419b4355c7d0097911..57dc88db57938760fee2958adfc9296e0a1ccef9 100644 (file)
--- 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,