io_uring: add support for fallocate()

This exposes fallocate(2) through io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5953d7f..7a4e00e 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -319,6 +319,7 @@ struct io_sync {
        loff_t                          len;
        loff_t                          off;
        int                             flags;
+       int                             mode;
 };
 
 struct io_cancel {
@@ -2101,6 +2102,54 @@ static int io_fsync(struct io_kiocb *req, struct io_kiocb **nxt,
        return 0;
 }
 
+static void io_fallocate_finish(struct io_wq_work **workptr)
+{
+       struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
+       struct io_kiocb *nxt = NULL;
+       int ret;
+
+       ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
+                               req->sync.len);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, &nxt);
+       if (nxt)
+               io_wq_assign_next(workptr, nxt);
+}
+
+static int io_fallocate_prep(struct io_kiocb *req,
+                            const struct io_uring_sqe *sqe)
+{
+       if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
+               return -EINVAL;
+
+       req->sync.off = READ_ONCE(sqe->off);
+       req->sync.len = READ_ONCE(sqe->addr);
+       req->sync.mode = READ_ONCE(sqe->len);
+       return 0;
+}
+
+static int io_fallocate(struct io_kiocb *req, struct io_kiocb **nxt,
+                       bool force_nonblock)
+{
+       struct io_wq_work *work, *old_work;
+
+       /* fallocate always requiring blocking context */
+       if (force_nonblock) {
+               io_put_req(req);
+               req->work.func = io_fallocate_finish;
+               return -EAGAIN;
+       }
+
+       work = old_work = &req->work;
+       io_fallocate_finish(&work);
+       if (work && work != old_work)
+               *nxt = container_of(work, struct io_kiocb, work);
+
+       return 0;
+}
+
 static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
        struct io_ring_ctx *ctx = req->ctx;
@@ -3123,6 +3172,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
        case IORING_OP_ACCEPT:
                ret = io_accept_prep(req, sqe);
                break;
+       case IORING_OP_FALLOCATE:
+               ret = io_fallocate_prep(req, sqe);
+               break;
        default:
                printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
                                req->opcode);
@@ -3277,6 +3329,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                }
                ret = io_async_cancel(req, nxt);
                break;
+       case IORING_OP_FALLOCATE:
+               if (sqe) {
+                       ret = io_fallocate_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_fallocate(req, nxt, force_nonblock);
+               break;
        default:
                ret = -EINVAL;
                break;

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 55cfcb7..ad1574f 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -76,6 +76,7 @@ enum {
        IORING_OP_ASYNC_CANCEL,
        IORING_OP_LINK_TIMEOUT,
        IORING_OP_CONNECT,
+       IORING_OP_FALLOCATE,
 
        /* this goes last, obviously */
        IORING_OP_LAST,