tests/9p: split virtio-9p-test.c into tests and 9p client part

This patch is pure refactoring, it does not change behaviour.

virtio-9p-test.c grew to 1657 lines. Let's split this file up between
actual 9p test cases vs. 9p test client, to make it easier to
concentrate on the actual 9p tests.

Move the 9p test client code to a new unit virtio-9p-client.c, which
are basically all functions and types prefixed with v9fs_* already.

Note that some client wrapper functions (do_*) are preserved in
virtio-9p-test.c, simply because these wrapper functions are going to
be wiped with subsequent patches anyway.

As the global QGuestAllocator variable is moved to virtio-9p-client.c,
add a new function v9fs_set_allocator() to be used by virtio-9p-test.c
instead of fiddling with a global variable across units and libraries.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <E1odrya-0004Fv-97@lizzy.crudebyte.com>

1 files changed, 684 insertions, 0 deletions

diff --git a/tests/qtest/libqos/virtio-9p-client.c b/tests/qtest/libqos/virtio-9p-client.c
new file mode 100644
index 0000000000..f5c35fd722
--- /dev/null
+++ b/tests/qtest/libqos/virtio-9p-client.c
@@ -0,0 +1,684 @@
+/*
+ * 9P network client for VirtIO 9P test cases (based on QTest)
+ *
+ * Copyright (c) 2014 SUSE LINUX Products GmbH
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+/*
+ * Not so fast! You might want to read the 9p developer docs first:
+ * https://wiki.qemu.org/Documentation/9p
+ */
+
+#include "qemu/osdep.h"
+#include "virtio-9p-client.h"
+
+#define QVIRTIO_9P_TIMEOUT_US (10 * 1000 * 1000)
+static QGuestAllocator *alloc;
+
+void v9fs_set_allocator(QGuestAllocator *t_alloc)
+{
+    alloc = t_alloc;
+}
+
+void v9fs_memwrite(P9Req *req, const void *addr, size_t len)
+{
+    qtest_memwrite(req->qts, req->t_msg + req->t_off, addr, len);
+    req->t_off += len;
+}
+
+void v9fs_memskip(P9Req *req, size_t len)
+{
+    req->r_off += len;
+}
+
+void v9fs_memread(P9Req *req, void *addr, size_t len)
+{
+    qtest_memread(req->qts, req->r_msg + req->r_off, addr, len);
+    req->r_off += len;
+}
+
+void v9fs_uint8_read(P9Req *req, uint8_t *val)
+{
+    v9fs_memread(req, val, 1);
+}
+
+void v9fs_uint16_write(P9Req *req, uint16_t val)
+{
+    uint16_t le_val = cpu_to_le16(val);
+
+    v9fs_memwrite(req, &le_val, 2);
+}
+
+void v9fs_uint16_read(P9Req *req, uint16_t *val)
+{
+    v9fs_memread(req, val, 2);
+    le16_to_cpus(val);
+}
+
+void v9fs_uint32_write(P9Req *req, uint32_t val)
+{
+    uint32_t le_val = cpu_to_le32(val);
+
+    v9fs_memwrite(req, &le_val, 4);
+}
+
+void v9fs_uint64_write(P9Req *req, uint64_t val)
+{
+    uint64_t le_val = cpu_to_le64(val);
+
+    v9fs_memwrite(req, &le_val, 8);
+}
+
+void v9fs_uint32_read(P9Req *req, uint32_t *val)
+{
+    v9fs_memread(req, val, 4);
+    le32_to_cpus(val);
+}
+
+void v9fs_uint64_read(P9Req *req, uint64_t *val)
+{
+    v9fs_memread(req, val, 8);
+    le64_to_cpus(val);
+}
+
+/* len[2] string[len] */
+uint16_t v9fs_string_size(const char *string)
+{
+    size_t len = strlen(string);
+
+    g_assert_cmpint(len, <=, UINT16_MAX - 2);
+
+    return 2 + len;
+}
+
+void v9fs_string_write(P9Req *req, const char *string)
+{
+    int len = strlen(string);
+
+    g_assert_cmpint(len, <=, UINT16_MAX);
+
+    v9fs_uint16_write(req, (uint16_t) len);
+    v9fs_memwrite(req, string, len);
+}
+
+void v9fs_string_read(P9Req *req, uint16_t *len, char **string)
+{
+    uint16_t local_len;
+
+    v9fs_uint16_read(req, &local_len);
+    if (len) {
+        *len = local_len;
+    }
+    if (string) {
+        *string = g_malloc(local_len + 1);
+        v9fs_memread(req, *string, local_len);
+        (*string)[local_len] = 0;
+    } else {
+        v9fs_memskip(req, local_len);
+    }
+}
+
+typedef struct {
+    uint32_t size;
+    uint8_t id;
+    uint16_t tag;
+} QEMU_PACKED P9Hdr;
+
+P9Req *v9fs_req_init(QVirtio9P *v9p, uint32_t size, uint8_t id,
+                     uint16_t tag)
+{
+    P9Req *req = g_new0(P9Req, 1);
+    uint32_t total_size = 7; /* 9P header has well-known size of 7 bytes */
+    P9Hdr hdr = {
+        .id = id,
+        .tag = cpu_to_le16(tag)
+    };
+
+    g_assert_cmpint(total_size, <=, UINT32_MAX - size);
+    total_size += size;
+    hdr.size = cpu_to_le32(total_size);
+
+    g_assert_cmpint(total_size, <=, P9_MAX_SIZE);
+
+    req->qts = global_qtest;
+    req->v9p = v9p;
+    req->t_size = total_size;
+    req->t_msg = guest_alloc(alloc, req->t_size);
+    v9fs_memwrite(req, &hdr, 7);
+    req->tag = tag;
+    return req;
+}
+
+void v9fs_req_send(P9Req *req)
+{
+    QVirtio9P *v9p = req->v9p;
+
+    req->r_msg = guest_alloc(alloc, P9_MAX_SIZE);
+    req->free_head = qvirtqueue_add(req->qts, v9p->vq, req->t_msg, req->t_size,
+                                    false, true);
+    qvirtqueue_add(req->qts, v9p->vq, req->r_msg, P9_MAX_SIZE, true, false);
+    qvirtqueue_kick(req->qts, v9p->vdev, v9p->vq, req->free_head);
+    req->t_off = 0;
+}
+
+static const char *rmessage_name(uint8_t id)
+{
+    return
+        id == P9_RLERROR ? "RLERROR" :
+        id == P9_RVERSION ? "RVERSION" :
+        id == P9_RATTACH ? "RATTACH" :
+        id == P9_RWALK ? "RWALK" :
+        id == P9_RLOPEN ? "RLOPEN" :
+        id == P9_RWRITE ? "RWRITE" :
+        id == P9_RMKDIR ? "RMKDIR" :
+        id == P9_RLCREATE ? "RLCREATE" :
+        id == P9_RSYMLINK ? "RSYMLINK" :
+        id == P9_RLINK ? "RLINK" :
+        id == P9_RUNLINKAT ? "RUNLINKAT" :
+        id == P9_RFLUSH ? "RFLUSH" :
+        id == P9_RREADDIR ? "READDIR" :
+        "<unknown>";
+}
+
+void v9fs_req_wait_for_reply(P9Req *req, uint32_t *len)
+{
+    QVirtio9P *v9p = req->v9p;
+
+    qvirtio_wait_used_elem(req->qts, v9p->vdev, v9p->vq, req->free_head, len,
+                           QVIRTIO_9P_TIMEOUT_US);
+}
+
+void v9fs_req_recv(P9Req *req, uint8_t id)
+{
+    P9Hdr hdr;
+
+    v9fs_memread(req, &hdr, 7);
+    hdr.size = ldl_le_p(&hdr.size);
+    hdr.tag = lduw_le_p(&hdr.tag);
+
+    g_assert_cmpint(hdr.size, >=, 7);
+    g_assert_cmpint(hdr.size, <=, P9_MAX_SIZE);
+    g_assert_cmpint(hdr.tag, ==, req->tag);
+
+    if (hdr.id != id) {
+        g_printerr("Received response %d (%s) instead of %d (%s)\n",
+                   hdr.id, rmessage_name(hdr.id), id, rmessage_name(id));
+
+        if (hdr.id == P9_RLERROR) {
+            uint32_t err;
+            v9fs_uint32_read(req, &err);
+            g_printerr("Rlerror has errno %d (%s)\n", err, strerror(err));
+        }
+    }
+    g_assert_cmpint(hdr.id, ==, id);
+}
+
+void v9fs_req_free(P9Req *req)
+{
+    guest_free(alloc, req->t_msg);
+    guest_free(alloc, req->r_msg);
+    g_free(req);
+}
+
+/* size[4] Rlerror tag[2] ecode[4] */
+void v9fs_rlerror(P9Req *req, uint32_t *err)
+{
+    v9fs_req_recv(req, P9_RLERROR);
+    v9fs_uint32_read(req, err);
+    v9fs_req_free(req);
+}
+
+/* size[4] Tversion tag[2] msize[4] version[s] */
+P9Req *v9fs_tversion(QVirtio9P *v9p, uint32_t msize, const char *version,
+                     uint16_t tag)
+{
+    P9Req *req;
+    uint32_t body_size = 4;
+    uint16_t string_size = v9fs_string_size(version);
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - string_size);
+    body_size += string_size;
+    req = v9fs_req_init(v9p, body_size, P9_TVERSION, tag);
+
+    v9fs_uint32_write(req, msize);
+    v9fs_string_write(req, version);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rversion tag[2] msize[4] version[s] */
+void v9fs_rversion(P9Req *req, uint16_t *len, char **version)
+{
+    uint32_t msize;
+
+    v9fs_req_recv(req, P9_RVERSION);
+    v9fs_uint32_read(req, &msize);
+
+    g_assert_cmpint(msize, ==, P9_MAX_SIZE);
+
+    if (len || version) {
+        v9fs_string_read(req, len, version);
+    }
+
+    v9fs_req_free(req);
+}
+
+/* size[4] Tattach tag[2] fid[4] afid[4] uname[s] aname[s] n_uname[4] */
+P9Req *v9fs_tattach(QVirtio9P *v9p, uint32_t fid, uint32_t n_uname,
+                    uint16_t tag)
+{
+    const char *uname = ""; /* ignored by QEMU */
+    const char *aname = ""; /* ignored by QEMU */
+    P9Req *req = v9fs_req_init(v9p, 4 + 4 + 2 + 2 + 4, P9_TATTACH, tag);
+
+    v9fs_uint32_write(req, fid);
+    v9fs_uint32_write(req, P9_NOFID);
+    v9fs_string_write(req, uname);
+    v9fs_string_write(req, aname);
+    v9fs_uint32_write(req, n_uname);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rattach tag[2] qid[13] */
+void v9fs_rattach(P9Req *req, v9fs_qid *qid)
+{
+    v9fs_req_recv(req, P9_RATTACH);
+    if (qid) {
+        v9fs_memread(req, qid, 13);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Twalk tag[2] fid[4] newfid[4] nwname[2] nwname*(wname[s]) */
+P9Req *v9fs_twalk(QVirtio9P *v9p, uint32_t fid, uint32_t newfid,
+                  uint16_t nwname, char *const wnames[], uint16_t tag)
+{
+    P9Req *req;
+    int i;
+    uint32_t body_size = 4 + 4 + 2;
+
+    for (i = 0; i < nwname; i++) {
+        uint16_t wname_size = v9fs_string_size(wnames[i]);
+
+        g_assert_cmpint(body_size, <=, UINT32_MAX - wname_size);
+        body_size += wname_size;
+    }
+    req = v9fs_req_init(v9p,  body_size, P9_TWALK, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_uint32_write(req, newfid);
+    v9fs_uint16_write(req, nwname);
+    for (i = 0; i < nwname; i++) {
+        v9fs_string_write(req, wnames[i]);
+    }
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rwalk tag[2] nwqid[2] nwqid*(wqid[13]) */
+void v9fs_rwalk(P9Req *req, uint16_t *nwqid, v9fs_qid **wqid)
+{
+    uint16_t local_nwqid;
+
+    v9fs_req_recv(req, P9_RWALK);
+    v9fs_uint16_read(req, &local_nwqid);
+    if (nwqid) {
+        *nwqid = local_nwqid;
+    }
+    if (wqid) {
+        *wqid = g_malloc(local_nwqid * 13);
+        v9fs_memread(req, *wqid, local_nwqid * 13);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Tgetattr tag[2] fid[4] request_mask[8] */
+P9Req *v9fs_tgetattr(QVirtio9P *v9p, uint32_t fid, uint64_t request_mask,
+                     uint16_t tag)
+{
+    P9Req *req;
+
+    req = v9fs_req_init(v9p, 4 + 8, P9_TGETATTR, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_uint64_write(req, request_mask);
+    v9fs_req_send(req);
+    return req;
+}
+
+/*
+ * size[4] Rgetattr tag[2] valid[8] qid[13] mode[4] uid[4] gid[4] nlink[8]
+ *                  rdev[8] size[8] blksize[8] blocks[8]
+ *                  atime_sec[8] atime_nsec[8] mtime_sec[8] mtime_nsec[8]
+ *                  ctime_sec[8] ctime_nsec[8] btime_sec[8] btime_nsec[8]
+ *                  gen[8] data_version[8]
+ */
+void v9fs_rgetattr(P9Req *req, v9fs_attr *attr)
+{
+    v9fs_req_recv(req, P9_RGETATTR);
+
+    v9fs_uint64_read(req, &attr->valid);
+    v9fs_memread(req, &attr->qid, 13);
+    v9fs_uint32_read(req, &attr->mode);
+    v9fs_uint32_read(req, &attr->uid);
+    v9fs_uint32_read(req, &attr->gid);
+    v9fs_uint64_read(req, &attr->nlink);
+    v9fs_uint64_read(req, &attr->rdev);
+    v9fs_uint64_read(req, &attr->size);
+    v9fs_uint64_read(req, &attr->blksize);
+    v9fs_uint64_read(req, &attr->blocks);
+    v9fs_uint64_read(req, &attr->atime_sec);
+    v9fs_uint64_read(req, &attr->atime_nsec);
+    v9fs_uint64_read(req, &attr->mtime_sec);
+    v9fs_uint64_read(req, &attr->mtime_nsec);
+    v9fs_uint64_read(req, &attr->ctime_sec);
+    v9fs_uint64_read(req, &attr->ctime_nsec);
+    v9fs_uint64_read(req, &attr->btime_sec);
+    v9fs_uint64_read(req, &attr->btime_nsec);
+    v9fs_uint64_read(req, &attr->gen);
+    v9fs_uint64_read(req, &attr->data_version);
+
+    v9fs_req_free(req);
+}
+
+/* size[4] Treaddir tag[2] fid[4] offset[8] count[4] */
+P9Req *v9fs_treaddir(QVirtio9P *v9p, uint32_t fid, uint64_t offset,
+                     uint32_t count, uint16_t tag)
+{
+    P9Req *req;
+
+    req = v9fs_req_init(v9p, 4 + 8 + 4, P9_TREADDIR, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_uint64_write(req, offset);
+    v9fs_uint32_write(req, count);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rreaddir tag[2] count[4] data[count] */
+void v9fs_rreaddir(P9Req *req, uint32_t *count, uint32_t *nentries,
+                   struct V9fsDirent **entries)
+{
+    uint32_t local_count;
+    struct V9fsDirent *e = NULL;
+    uint16_t slen;
+    uint32_t n = 0;
+
+    v9fs_req_recv(req, P9_RREADDIR);
+    v9fs_uint32_read(req, &local_count);
+
+    if (count) {
+        *count = local_count;
+    }
+
+    for (int32_t togo = (int32_t)local_count;
+         togo >= 13 + 8 + 1 + 2;
+         togo -= 13 + 8 + 1 + 2 + slen, ++n)
+    {
+        if (!e) {
+            e = g_new(struct V9fsDirent, 1);
+            if (entries) {
+                *entries = e;
+            }
+        } else {
+            e = e->next = g_new(struct V9fsDirent, 1);
+        }
+        e->next = NULL;
+        /* qid[13] offset[8] type[1] name[s] */
+        v9fs_memread(req, &e->qid, 13);
+        v9fs_uint64_read(req, &e->offset);
+        v9fs_uint8_read(req, &e->type);
+        v9fs_string_read(req, &slen, &e->name);
+    }
+
+    if (nentries) {
+        *nentries = n;
+    }
+
+    v9fs_req_free(req);
+}
+
+void v9fs_free_dirents(struct V9fsDirent *e)
+{
+    struct V9fsDirent *next = NULL;
+
+    for (; e; e = next) {
+        next = e->next;
+        g_free(e->name);
+        g_free(e);
+    }
+}
+
+/* size[4] Tlopen tag[2] fid[4] flags[4] */
+P9Req *v9fs_tlopen(QVirtio9P *v9p, uint32_t fid, uint32_t flags,
+                   uint16_t tag)
+{
+    P9Req *req;
+
+    req = v9fs_req_init(v9p,  4 + 4, P9_TLOPEN, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_uint32_write(req, flags);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rlopen tag[2] qid[13] iounit[4] */
+void v9fs_rlopen(P9Req *req, v9fs_qid *qid, uint32_t *iounit)
+{
+    v9fs_req_recv(req, P9_RLOPEN);
+    if (qid) {
+        v9fs_memread(req, qid, 13);
+    } else {
+        v9fs_memskip(req, 13);
+    }
+    if (iounit) {
+        v9fs_uint32_read(req, iounit);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Twrite tag[2] fid[4] offset[8] count[4] data[count] */
+P9Req *v9fs_twrite(QVirtio9P *v9p, uint32_t fid, uint64_t offset,
+                   uint32_t count, const void *data, uint16_t tag)
+{
+    P9Req *req;
+    uint32_t body_size = 4 + 8 + 4;
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - count);
+    body_size += count;
+    req = v9fs_req_init(v9p,  body_size, P9_TWRITE, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_uint64_write(req, offset);
+    v9fs_uint32_write(req, count);
+    v9fs_memwrite(req, data, count);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rwrite tag[2] count[4] */
+void v9fs_rwrite(P9Req *req, uint32_t *count)
+{
+    v9fs_req_recv(req, P9_RWRITE);
+    if (count) {
+        v9fs_uint32_read(req, count);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Tflush tag[2] oldtag[2] */
+P9Req *v9fs_tflush(QVirtio9P *v9p, uint16_t oldtag, uint16_t tag)
+{
+    P9Req *req;
+
+    req = v9fs_req_init(v9p,  2, P9_TFLUSH, tag);
+    v9fs_uint32_write(req, oldtag);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rflush tag[2] */
+void v9fs_rflush(P9Req *req)
+{
+    v9fs_req_recv(req, P9_RFLUSH);
+    v9fs_req_free(req);
+}
+
+/* size[4] Tmkdir tag[2] dfid[4] name[s] mode[4] gid[4] */
+P9Req *v9fs_tmkdir(QVirtio9P *v9p, uint32_t dfid, const char *name,
+                   uint32_t mode, uint32_t gid, uint16_t tag)
+{
+    P9Req *req;
+
+    uint32_t body_size = 4 + 4 + 4;
+    uint16_t string_size = v9fs_string_size(name);
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - string_size);
+    body_size += string_size;
+
+    req = v9fs_req_init(v9p, body_size, P9_TMKDIR, tag);
+    v9fs_uint32_write(req, dfid);
+    v9fs_string_write(req, name);
+    v9fs_uint32_write(req, mode);
+    v9fs_uint32_write(req, gid);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rmkdir tag[2] qid[13] */
+void v9fs_rmkdir(P9Req *req, v9fs_qid *qid)
+{
+    v9fs_req_recv(req, P9_RMKDIR);
+    if (qid) {
+        v9fs_memread(req, qid, 13);
+    } else {
+        v9fs_memskip(req, 13);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Tlcreate tag[2] fid[4] name[s] flags[4] mode[4] gid[4] */
+P9Req *v9fs_tlcreate(QVirtio9P *v9p, uint32_t fid, const char *name,
+                     uint32_t flags, uint32_t mode, uint32_t gid,
+                     uint16_t tag)
+{
+    P9Req *req;
+
+    uint32_t body_size = 4 + 4 + 4 + 4;
+    uint16_t string_size = v9fs_string_size(name);
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - string_size);
+    body_size += string_size;
+
+    req = v9fs_req_init(v9p, body_size, P9_TLCREATE, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_string_write(req, name);
+    v9fs_uint32_write(req, flags);
+    v9fs_uint32_write(req, mode);
+    v9fs_uint32_write(req, gid);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rlcreate tag[2] qid[13] iounit[4] */
+void v9fs_rlcreate(P9Req *req, v9fs_qid *qid, uint32_t *iounit)
+{
+    v9fs_req_recv(req, P9_RLCREATE);
+    if (qid) {
+        v9fs_memread(req, qid, 13);
+    } else {
+        v9fs_memskip(req, 13);
+    }
+    if (iounit) {
+        v9fs_uint32_read(req, iounit);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Tsymlink tag[2] fid[4] name[s] symtgt[s] gid[4] */
+P9Req *v9fs_tsymlink(QVirtio9P *v9p, uint32_t fid, const char *name,
+                     const char *symtgt, uint32_t gid, uint16_t tag)
+{
+    P9Req *req;
+
+    uint32_t body_size = 4 + 4;
+    uint16_t string_size = v9fs_string_size(name) + v9fs_string_size(symtgt);
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - string_size);
+    body_size += string_size;
+
+    req = v9fs_req_init(v9p, body_size, P9_TSYMLINK, tag);
+    v9fs_uint32_write(req, fid);
+    v9fs_string_write(req, name);
+    v9fs_string_write(req, symtgt);
+    v9fs_uint32_write(req, gid);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rsymlink tag[2] qid[13] */
+void v9fs_rsymlink(P9Req *req, v9fs_qid *qid)
+{
+    v9fs_req_recv(req, P9_RSYMLINK);
+    if (qid) {
+        v9fs_memread(req, qid, 13);
+    } else {
+        v9fs_memskip(req, 13);
+    }
+    v9fs_req_free(req);
+}
+
+/* size[4] Tlink tag[2] dfid[4] fid[4] name[s] */
+P9Req *v9fs_tlink(QVirtio9P *v9p, uint32_t dfid, uint32_t fid,
+                  const char *name, uint16_t tag)
+{
+    P9Req *req;
+
+    uint32_t body_size = 4 + 4;
+    uint16_t string_size = v9fs_string_size(name);
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - string_size);
+    body_size += string_size;
+
+    req = v9fs_req_init(v9p, body_size, P9_TLINK, tag);
+    v9fs_uint32_write(req, dfid);
+    v9fs_uint32_write(req, fid);
+    v9fs_string_write(req, name);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Rlink tag[2] */
+void v9fs_rlink(P9Req *req)
+{
+    v9fs_req_recv(req, P9_RLINK);
+    v9fs_req_free(req);
+}
+
+/* size[4] Tunlinkat tag[2] dirfd[4] name[s] flags[4] */
+P9Req *v9fs_tunlinkat(QVirtio9P *v9p, uint32_t dirfd, const char *name,
+                      uint32_t flags, uint16_t tag)
+{
+    P9Req *req;
+
+    uint32_t body_size = 4 + 4;
+    uint16_t string_size = v9fs_string_size(name);
+
+    g_assert_cmpint(body_size, <=, UINT32_MAX - string_size);
+    body_size += string_size;
+
+    req = v9fs_req_init(v9p, body_size, P9_TUNLINKAT, tag);
+    v9fs_uint32_write(req, dirfd);
+    v9fs_string_write(req, name);
+    v9fs_uint32_write(req, flags);
+    v9fs_req_send(req);
+    return req;
+}
+
+/* size[4] Runlinkat tag[2] */
+void v9fs_runlinkat(P9Req *req)
+{
+    v9fs_req_recv(req, P9_RUNLINKAT);
+    v9fs_req_free(req);
+}