io_uring: add support for IORING_OP_STATX

This provides support for async statx(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 4325068..115c7d4 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -379,9 +379,13 @@ struct io_sr_msg {
 struct io_open {
        struct file                     *file;
        int                             dfd;
-       umode_t                         mode;
+       union {
+               umode_t                 mode;
+               unsigned                mask;
+       };
        const char __user               *fname;
        struct filename                 *filename;
+       struct statx __user             *buffer;
        int                             flags;
 };
 
@@ -2266,6 +2270,74 @@ err:
        return 0;
 }
 
+static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       unsigned lookup_flags;
+       int ret;
+
+       if (sqe->ioprio || sqe->buf_index)
+               return -EINVAL;
+
+       req->open.dfd = READ_ONCE(sqe->fd);
+       req->open.mask = READ_ONCE(sqe->len);
+       req->open.fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+       req->open.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+       req->open.flags = READ_ONCE(sqe->statx_flags);
+
+       if (vfs_stat_set_lookup_flags(&lookup_flags, req->open.flags))
+               return -EINVAL;
+
+       req->open.filename = getname_flags(req->open.fname, lookup_flags, NULL);
+       if (IS_ERR(req->open.filename)) {
+               ret = PTR_ERR(req->open.filename);
+               req->open.filename = NULL;
+               return ret;
+       }
+
+       return 0;
+}
+
+static int io_statx(struct io_kiocb *req, struct io_kiocb **nxt,
+                   bool force_nonblock)
+{
+       struct io_open *ctx = &req->open;
+       unsigned lookup_flags;
+       struct path path;
+       struct kstat stat;
+       int ret;
+
+       if (force_nonblock)
+               return -EAGAIN;
+
+       if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->flags))
+               return -EINVAL;
+
+retry:
+       /* filename_lookup() drops it, keep a reference */
+       ctx->filename->refcnt++;
+
+       ret = filename_lookup(ctx->dfd, ctx->filename, lookup_flags, &path,
+                               NULL);
+       if (ret)
+               goto err;
+
+       ret = vfs_getattr(&path, &stat, ctx->mask, ctx->flags);
+       path_put(&path);
+       if (retry_estale(ret, lookup_flags)) {
+               lookup_flags |= LOOKUP_REVAL;
+               goto retry;
+       }
+       if (!ret)
+               ret = cp_statx(&stat, ctx->buffer);
+err:
+       putname(ctx->filename);
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_cqring_add_event(req, ret);
+       io_put_req_find_next(req, nxt);
+       return 0;
+}
+
 static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
        /*
@@ -3427,6 +3499,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
        case IORING_OP_FILES_UPDATE:
                ret = io_files_update_prep(req, sqe);
                break;
+       case IORING_OP_STATX:
+               ret = io_statx_prep(req, sqe);
+               break;
        default:
                printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
                                req->opcode);
@@ -3613,6 +3688,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                }
                ret = io_files_update(req, force_nonblock);
                break;
+       case IORING_OP_STATX:
+               if (sqe) {
+                       ret = io_statx_prep(req, sqe);
+                       if (ret)
+                               break;
+               }
+               ret = io_statx(req, nxt, force_nonblock);
+               break;
        default:
                ret = -EINVAL;
                break;
@@ -3699,6 +3782,7 @@ static int io_req_needs_file(struct io_kiocb *req, int fd)
        case IORING_OP_LINK_TIMEOUT:
                return 0;
        case IORING_OP_OPENAT:
+       case IORING_OP_STATX:
                return fd != -1;
        default:
                if (io_req_op_valid(req->opcode))

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index ca436b9..3f45f7c 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -35,6 +35,7 @@ struct io_uring_sqe {
                __u32           accept_flags;
                __u32           cancel_flags;
                __u32           open_flags;
+               __u32           statx_flags;
        };
        __u64   user_data;      /* data to be passed back at completion time */
        union {
@@ -81,6 +82,7 @@ enum {
        IORING_OP_OPENAT,
        IORING_OP_CLOSE,
        IORING_OP_FILES_UPDATE,
+       IORING_OP_STATX,
 
        /* this goes last, obviously */
        IORING_OP_LAST,