[PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[Christian Schoenebeck]

Split out walking a directory path to a separate new utility function
fs_walk_fid() and use that function in fs_mkdir().

The code difference saved this way is not much, but we'll use that new
fs_walk_fid() function in the upcoming patches, so it will avoid quite
some code duplication after all.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index c15908f27b..dc724bbb1e 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -967,13 +967,12 @@ static void fs_flush_ignored(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(wnames[0]);
 }
 
-static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
-                     const char *path, const char *cname)
+/* utility function: walk to requested dir and return fid for that dir */
+static uint32_t fs_walk_fid(void *obj, void *data, QGuestAllocator *t_alloc,
+                            const char *path)
 {
     QVirtio9P *v9p = obj;
-    alloc = t_alloc;
     char **wnames;
-    char *const name = g_strdup(cname);
     P9Req *req;
     const uint32_t fid = genfid();
 
@@ -983,12 +982,26 @@ static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
     v9fs_req_wait_for_reply(req, NULL);
     v9fs_rwalk(req, NULL, NULL);
 
+    split_free(&wnames);
+    return fid;
+}
+
+static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
+                     const char *path, const char *cname)
+{
+    QVirtio9P *v9p = obj;
+    alloc = t_alloc;
+    char *const name = g_strdup(cname);
+    uint32_t fid;
+    P9Req *req;
+
+    fid = fs_walk_fid(v9p, data, t_alloc, path);
+
     req = v9fs_tmkdir(v9p, fid, name, 0750, 0, 0);
     v9fs_req_wait_for_reply(req, NULL);
     v9fs_rmkdir(req, NULL);
 
     g_free(name);
-    split_free(&wnames);
 }
 
 static void fs_readdir_split_128(void *obj, void *data,
-- 
2.20.1

[PATCH 2/8] tests/9pfs: add local unlinkat directory test

[Christian Schoenebeck]

This test case uses a Tunlinkat 9p request with flag AT_REMOVEDIR
(see 'man 2 unlink') to remove a directory from host's test directory.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 72 ++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index dc724bbb1e..990d074d33 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -258,6 +258,7 @@ static const char *rmessage_name(uint8_t id)
         id == P9_RLOPEN ? "RLOPEN" :
         id == P9_RWRITE ? "RWRITE" :
         id == P9_RMKDIR ? "RMKDIR" :
+        id == P9_RUNLINKAT ? "RUNLINKAT" :
         id == P9_RFLUSH ? "RFLUSH" :
         id == P9_RREADDIR ? "READDIR" :
         "<unknown>";
@@ -668,6 +669,33 @@ static void v9fs_rmkdir(P9Req *req, v9fs_qid *qid)
     v9fs_req_free(req);
 }
 
+/* size[4] Tunlinkat tag[2] dirfd[4] name[s] flags[4] */
+static 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] */
+static void v9fs_runlinkat(P9Req *req)
+{
+    v9fs_req_recv(req, P9_RUNLINKAT);
+    v9fs_req_free(req);
+}
+
 /* basic readdir test where reply fits into a single response message */
 static void fs_readdir(void *obj, void *data, QGuestAllocator *t_alloc)
 {
@@ -1004,6 +1032,24 @@ static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
     g_free(name);
 }
 
+static void fs_unlinkat(void *obj, void *data, QGuestAllocator *t_alloc,
+                        const char *atpath, const char *rpath, uint32_t flags)
+{
+    QVirtio9P *v9p = obj;
+    alloc = t_alloc;
+    char *const name = g_strdup(rpath);
+    uint32_t fid;
+    P9Req *req;
+
+    fid = fs_walk_fid(v9p, data, t_alloc, atpath);
+
+    req = v9fs_tunlinkat(v9p, fid, name, flags, 0);
+    v9fs_req_wait_for_reply(req, NULL);
+    v9fs_runlinkat(req);
+
+    g_free(name);
+}
+
 static void fs_readdir_split_128(void *obj, void *data,
                                  QGuestAllocator *t_alloc)
 {
@@ -1046,6 +1092,31 @@ static void fs_create_dir(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(root_path);
 }
 
+static void fs_unlinkat_dir(void *obj, void *data, QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    struct stat st;
+    char *root_path = virtio_9p_test_path("");
+    char *new_dir = virtio_9p_test_path("02");
+
+    g_assert(root_path != NULL);
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "02");
+
+    /* check if created directory really exists now ... */
+    g_assert(stat(new_dir, &st) == 0);
+    /* ... and is actually a directory */
+    g_assert((st.st_mode & S_IFMT) == S_IFDIR);
+
+    fs_unlinkat(v9p, data, t_alloc, "/", "02", AT_REMOVEDIR);
+    /* directory should be gone now */
+    g_assert(stat(new_dir, &st) != 0);
+
+    g_free(new_dir);
+    g_free(root_path);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1086,6 +1157,7 @@ static void register_virtio_9p_test(void)
     opts.before = assign_9p_local_driver;
     qos_add_test("local/config", "virtio-9p", pci_config,  &opts);
     qos_add_test("local/create_dir", "virtio-9p", fs_create_dir, &opts);
+    qos_add_test("local/unlinkat_dir", "virtio-9p", fs_unlinkat_dir, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 5/8] tests/9pfs: add local Tsymlink test

[Christian Schoenebeck]

This test case uses a Tsymlink 9p request to create a symbolic link using
the 9pfs 'local' fs driver.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 78 ++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index 06a9f10d34..78f4ed7e5f 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -259,6 +259,7 @@ static const char *rmessage_name(uint8_t id)
         id == P9_RWRITE ? "RWRITE" :
         id == P9_RMKDIR ? "RMKDIR" :
         id == P9_RLCREATE ? "RLCREATE" :
+        id == P9_RSYMLINK ? "RSYMLINK" :
         id == P9_RUNLINKAT ? "RUNLINKAT" :
         id == P9_RFLUSH ? "RFLUSH" :
         id == P9_RREADDIR ? "READDIR" :
@@ -708,6 +709,39 @@ static void v9fs_rlcreate(P9Req *req, v9fs_qid *qid, uint32_t *iounit)
     v9fs_req_free(req);
 }
 
+/* size[4] Tsymlink tag[2] fid[4] name[s] symtgt[s] gid[4] */
+static 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] */
+static 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] Tunlinkat tag[2] dirfd[4] name[s] flags[4] */
 static P9Req *v9fs_tunlinkat(QVirtio9P *v9p, uint32_t dirfd, const char *name,
                              uint32_t flags, uint16_t tag)
@@ -1091,6 +1125,27 @@ static uint32_t fs_lcreate(void *obj, void *data, QGuestAllocator *t_alloc,
     return fid;
 }
 
+/* create symlink named @a clink in directory @a path pointing to @a to */
+static void fs_symlink(void *obj, void *data, QGuestAllocator *t_alloc,
+                       const char *path, const char *clink, const char *to)
+{
+    QVirtio9P *v9p = obj;
+    alloc = t_alloc;
+    char *const name = g_strdup(clink);
+    char *const dst = g_strdup(to);
+    uint32_t fid;
+    P9Req *req;
+
+    fid = fs_walk_fid(v9p, data, t_alloc, path);
+
+    req = v9fs_tsymlink(v9p, fid, name, dst, 0, 0);
+    v9fs_req_wait_for_reply(req, NULL);
+    v9fs_rsymlink(req, NULL);
+
+    g_free(dst);
+    g_free(name);
+}
+
 static void fs_unlinkat(void *obj, void *data, QGuestAllocator *t_alloc,
                         const char *atpath, const char *rpath, uint32_t flags)
 {
@@ -1216,6 +1271,28 @@ static void fs_unlinkat_file(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(new_file);
 }
 
+static void fs_symlink_file(void *obj, void *data, QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    struct stat st;
+    char *real_file = virtio_9p_test_path("05/real_file");
+    char *symlink_file = virtio_9p_test_path("05/symlink_file");
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "05");
+    fs_lcreate(v9p, data, t_alloc, "05", "real_file");
+    g_assert(stat(real_file, &st) == 0);
+    g_assert((st.st_mode & S_IFMT) == S_IFREG);
+
+    fs_symlink(v9p, data, t_alloc, "05", "symlink_file", "real_file");
+
+    /* check if created link exists now */
+    g_assert(stat(symlink_file, &st) == 0);
+
+    g_free(symlink_file);
+    g_free(real_file);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1259,6 +1336,7 @@ static void register_virtio_9p_test(void)
     qos_add_test("local/unlinkat_dir", "virtio-9p", fs_unlinkat_dir, &opts);
     qos_add_test("local/create_file", "virtio-9p", fs_create_file, &opts);
     qos_add_test("local/unlinkat_file", "virtio-9p", fs_unlinkat_file, &opts);
+    qos_add_test("local/symlink_file", "virtio-9p", fs_symlink_file, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 3/8] tests/9pfs: add local Tlcreate test

[Christian Schoenebeck]

This test case uses a Tlcreate 9p request to create a regular file inside
host's test directory.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 78 ++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index 990d074d33..1b133f52bd 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -258,6 +258,7 @@ static const char *rmessage_name(uint8_t id)
         id == P9_RLOPEN ? "RLOPEN" :
         id == P9_RWRITE ? "RWRITE" :
         id == P9_RMKDIR ? "RMKDIR" :
+        id == P9_RLCREATE ? "RLCREATE" :
         id == P9_RUNLINKAT ? "RUNLINKAT" :
         id == P9_RFLUSH ? "RFLUSH" :
         id == P9_RREADDIR ? "READDIR" :
@@ -669,6 +670,44 @@ static void v9fs_rmkdir(P9Req *req, v9fs_qid *qid)
     v9fs_req_free(req);
 }
 
+/* size[4] Tlcreate tag[2] fid[4] name[s] flags[4] mode[4] gid[4] */
+static 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] */
+static 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] Tunlinkat tag[2] dirfd[4] name[s] flags[4] */
 static P9Req *v9fs_tunlinkat(QVirtio9P *v9p, uint32_t dirfd, const char *name,
                              uint32_t flags, uint16_t tag)
@@ -1032,6 +1071,26 @@ static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
     g_free(name);
 }
 
+/* create a regular file with Tlcreate and return file's fid */
+static uint32_t fs_lcreate(void *obj, void *data, QGuestAllocator *t_alloc,
+                           const char *path, const char *cname)
+{
+    QVirtio9P *v9p = obj;
+    alloc = t_alloc;
+    char *const name = g_strdup(cname);
+    uint32_t fid;
+    P9Req *req;
+
+    fid = fs_walk_fid(v9p, data, t_alloc, path);
+
+    req = v9fs_tlcreate(v9p, fid, name, 0, 0750, 0, 0);
+    v9fs_req_wait_for_reply(req, NULL);
+    v9fs_rlcreate(req, NULL, NULL);
+
+    g_free(name);
+    return fid;
+}
+
 static void fs_unlinkat(void *obj, void *data, QGuestAllocator *t_alloc,
                         const char *atpath, const char *rpath, uint32_t flags)
 {
@@ -1117,6 +1176,24 @@ static void fs_unlinkat_dir(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(root_path);
 }
 
+static void fs_create_file(void *obj, void *data, QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    struct stat st;
+    char *new_file = virtio_9p_test_path("03/1st_file");
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "03");
+    fs_lcreate(v9p, data, t_alloc, "03", "1st_file");
+
+    /* check if created file exists now ... */
+    g_assert(stat(new_file, &st) == 0);
+    /* ... and is a regular file */
+    g_assert((st.st_mode & S_IFMT) == S_IFREG);
+
+    g_free(new_file);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1158,6 +1235,7 @@ static void register_virtio_9p_test(void)
     qos_add_test("local/config", "virtio-9p", pci_config,  &opts);
     qos_add_test("local/create_dir", "virtio-9p", fs_create_dir, &opts);
     qos_add_test("local/unlinkat_dir", "virtio-9p", fs_unlinkat_dir, &opts);
+    qos_add_test("local/create_file", "virtio-9p", fs_create_file, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 4/8] tests/9pfs: add local unlinkat file test

[Christian Schoenebeck]

This test case uses a Tunlinkat request to remove a regular file using
the 9pfs 'local' fs driver.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index 1b133f52bd..06a9f10d34 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -1194,6 +1194,28 @@ static void fs_create_file(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(new_file);
 }
 
+static void fs_unlinkat_file(void *obj, void *data, QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    struct stat st;
+    char *new_file = virtio_9p_test_path("04/doa_file");
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "04");
+    fs_lcreate(v9p, data, t_alloc, "04", "doa_file");
+
+    /* check if created file exists now ... */
+    g_assert(stat(new_file, &st) == 0);
+    /* ... and is a regular file */
+    g_assert((st.st_mode & S_IFMT) == S_IFREG);
+
+    fs_unlinkat(v9p, data, t_alloc, "04", "doa_file", 0);
+    /* file should be gone now */
+    g_assert(stat(new_file, &st) != 0);
+
+    g_free(new_file);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1236,6 +1258,7 @@ static void register_virtio_9p_test(void)
     qos_add_test("local/create_dir", "virtio-9p", fs_create_dir, &opts);
     qos_add_test("local/unlinkat_dir", "virtio-9p", fs_unlinkat_dir, &opts);
     qos_add_test("local/create_file", "virtio-9p", fs_create_file, &opts);
+    qos_add_test("local/unlinkat_file", "virtio-9p", fs_unlinkat_file, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 6/8] tests/9pfs: add local unlinkat symlink test

[Christian Schoenebeck]

This test case uses a Tunlinkat request to remove a symlink using
the 9pfs 'local' fs driver.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index 78f4ed7e5f..f7d18f6274 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -1293,6 +1293,31 @@ static void fs_symlink_file(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(real_file);
 }
 
+static void fs_unlinkat_symlink(void *obj, void *data,
+                                QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    struct stat st;
+    char *real_file = virtio_9p_test_path("06/real_file");
+    char *symlink_file = virtio_9p_test_path("06/symlink_file");
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "06");
+    fs_lcreate(v9p, data, t_alloc, "06", "real_file");
+    g_assert(stat(real_file, &st) == 0);
+    g_assert((st.st_mode & S_IFMT) == S_IFREG);
+
+    fs_symlink(v9p, data, t_alloc, "06", "symlink_file", "real_file");
+    g_assert(stat(symlink_file, &st) == 0);
+
+    fs_unlinkat(v9p, data, t_alloc, "06", "symlink_file", 0);
+    /* symlink should be gone now */
+    g_assert(stat(symlink_file, &st) != 0);
+
+    g_free(symlink_file);
+    g_free(real_file);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1337,6 +1362,7 @@ static void register_virtio_9p_test(void)
     qos_add_test("local/create_file", "virtio-9p", fs_create_file, &opts);
     qos_add_test("local/unlinkat_file", "virtio-9p", fs_unlinkat_file, &opts);
     qos_add_test("local/symlink_file", "virtio-9p", fs_symlink_file, &opts);
+    qos_add_test("local/unlinkat_symlink", "virtio-9p", fs_unlinkat_symlink, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 7/8] tests/9pfs: add local Tlink test

[Christian Schoenebeck]

This test case uses a Tlink request to create a hard link to a regular
file using the 9pfs 'local' fs driver.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 61 ++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index f7d18f6274..447d8e3344 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -260,6 +260,7 @@ static const char *rmessage_name(uint8_t id)
         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" :
@@ -742,6 +743,33 @@ static void v9fs_rsymlink(P9Req *req, v9fs_qid *qid)
     v9fs_req_free(req);
 }
 
+/* size[4] Tlink tag[2] dfid[4] fid[4] name[s] */
+static 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] */
+static 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] */
 static P9Req *v9fs_tunlinkat(QVirtio9P *v9p, uint32_t dirfd, const char *name,
                              uint32_t flags, uint16_t tag)
@@ -1318,6 +1346,38 @@ static void fs_unlinkat_symlink(void *obj, void *data,
     g_free(real_file);
 }
 
+static void fs_hardlink_file(void *obj, void *data, QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    P9Req *req;
+    uint32_t dfid, fid;
+    struct stat st_real, st_link;
+    char *real_file = virtio_9p_test_path("07/real_file");
+    char *hardlink_file = virtio_9p_test_path("07/hardlink_file");
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "07");
+    fid = fs_lcreate(v9p, data, t_alloc, "07", "real_file");
+    g_assert(stat(real_file, &st_real) == 0);
+    g_assert((st_real.st_mode & S_IFMT) == S_IFREG);
+
+    dfid = fs_walk_fid(v9p, data, t_alloc, "07");
+
+    req = v9fs_tlink(v9p, dfid, fid, "hardlink_file", 0);
+    v9fs_req_wait_for_reply(req, NULL);
+    v9fs_rlink(req);
+
+    /* check if link exists now ... */
+    g_assert(stat(hardlink_file, &st_link) == 0);
+    /* ... and it's a hard link, right? */
+    g_assert((st_link.st_mode & S_IFMT) == S_IFREG);
+    g_assert(st_link.st_dev == st_real.st_dev);
+    g_assert(st_link.st_ino == st_real.st_ino);
+
+    g_free(hardlink_file);
+    g_free(real_file);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1363,6 +1423,7 @@ static void register_virtio_9p_test(void)
     qos_add_test("local/unlinkat_file", "virtio-9p", fs_unlinkat_file, &opts);
     qos_add_test("local/symlink_file", "virtio-9p", fs_symlink_file, &opts);
     qos_add_test("local/unlinkat_symlink", "virtio-9p", fs_unlinkat_symlink, &opts);
+    qos_add_test("local/hardlink_file", "virtio-9p", fs_hardlink_file, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 8/8] tests/9pfs: add local unlinkat hard link test

[Christian Schoenebeck]

This test case uses a Tunlinkat request to remove a previously hard
linked file by using the 9pfs 'local' fs driver.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 tests/qtest/virtio-9p-test.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
index 447d8e3344..2e50445745 100644
--- a/tests/qtest/virtio-9p-test.c
+++ b/tests/qtest/virtio-9p-test.c
@@ -1378,6 +1378,39 @@ static void fs_hardlink_file(void *obj, void *data, QGuestAllocator *t_alloc)
     g_free(real_file);
 }
 
+static void fs_unlinkat_hardlink(void *obj, void *data,
+                                 QGuestAllocator *t_alloc)
+{
+    QVirtio9P *v9p = obj;
+    P9Req *req;
+    uint32_t dfid, fid;
+    struct stat st_real, st_link;
+    char *real_file = virtio_9p_test_path("08/real_file");
+    char *hardlink_file = virtio_9p_test_path("08/hardlink_file");
+
+    fs_attach(v9p, NULL, t_alloc);
+    fs_mkdir(v9p, data, t_alloc, "/", "08");
+    fid = fs_lcreate(v9p, data, t_alloc, "08", "real_file");
+    g_assert(stat(real_file, &st_real) == 0);
+    g_assert((st_real.st_mode & S_IFMT) == S_IFREG);
+
+    dfid = fs_walk_fid(v9p, data, t_alloc, "08");
+
+    req = v9fs_tlink(v9p, dfid, fid, "hardlink_file", 0);
+    v9fs_req_wait_for_reply(req, NULL);
+    v9fs_rlink(req);
+    g_assert(stat(hardlink_file, &st_link) == 0);
+
+    fs_unlinkat(v9p, data, t_alloc, "08", "hardlink_file", 0);
+    /* symlink should be gone now */
+    g_assert(stat(hardlink_file, &st_link) != 0);
+    /* and old file should still exist */
+    g_assert(stat(real_file, &st_real) == 0);
+
+    g_free(hardlink_file);
+    g_free(real_file);
+}
+
 static void *assign_9p_local_driver(GString *cmd_line, void *arg)
 {
     virtio_9p_assign_local_driver(cmd_line, "security_model=mapped-xattr");
@@ -1424,6 +1457,7 @@ static void register_virtio_9p_test(void)
     qos_add_test("local/symlink_file", "virtio-9p", fs_symlink_file, &opts);
     qos_add_test("local/unlinkat_symlink", "virtio-9p", fs_unlinkat_symlink, &opts);
     qos_add_test("local/hardlink_file", "virtio-9p", fs_hardlink_file, &opts);
+    qos_add_test("local/unlinkat_hardlink", "virtio-9p", fs_unlinkat_hardlink, &opts);
 }
 
 libqos_init(register_virtio_9p_test);
-- 
2.20.1

[PATCH 0/8] 9pfs: more local tests

[Christian Schoenebeck]

Just a bunch of more test case using the 9pfs 'local' fs driver backend,
namely for these 9p requests:

* Tunlinkat, Tlcreate, Tsymlink and Tlink.

Christian Schoenebeck (8):
  tests/9pfs: simplify fs_mkdir()
  tests/9pfs: add local unlinkat directory test
  tests/9pfs: add local Tlcreate test
  tests/9pfs: add local unlinkat file test
  tests/9pfs: add local Tsymlink test
  tests/9pfs: add local unlinkat symlink test
  tests/9pfs: add local Tlink test
  tests/9pfs: add local unlinkat hard link test

 tests/qtest/virtio-9p-test.c | 395 ++++++++++++++++++++++++++++++++++-
 1 file changed, 390 insertions(+), 5 deletions(-)

-- 
2.20.1

Re: [PATCH 7/8] tests/9pfs: add local Tlink test

[Christian Schoenebeck]

On Dienstag, 20. Oktober 2020 01:13:24 CEST Christian Schoenebeck wrote:
> This test case uses a Tlink request to create a hard link to a regular
> file using the 9pfs 'local' fs driver.
> 
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---
>  tests/qtest/virtio-9p-test.c | 61 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 61 insertions(+)
> 
> diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> index f7d18f6274..447d8e3344 100644
> --- a/tests/qtest/virtio-9p-test.c
> +++ b/tests/qtest/virtio-9p-test.c
> @@ -260,6 +260,7 @@ static const char *rmessage_name(uint8_t id)
>          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" :
> @@ -742,6 +743,33 @@ static void v9fs_rsymlink(P9Req *req, v9fs_qid *qid)
>      v9fs_req_free(req);
>  }
> 
> +/* size[4] Tlink tag[2] dfid[4] fid[4] name[s] */
> +static P9Req *v9fs_tlink(QVirtio9P *v9p, uint32_t dfid, uint32_t fid,
> +                         const char *name, uint16_t tag)
> +{

This hard-link test was actually motived by an issue that I recently 
encountered on a machine: it fails to create any hard links with 9p. This 
particular test case succeeds though.

I think the problem is that recent libvirt versions enable qemu's sandbox 
feature by default which filters syscalls. Fact is, any linkat() call fails on 
that machine with EACCES now. I couldn't reproduce it on my development 
machine yet though. I guess it's a difference in white/black-list seccomp 
config or something. Not sure yet if there is some change required on 9p side 
or whether it's really just a seccomp config issue.

P.S. Noisy days from my side, but this is probably the last batch of patches 
from my side in a while, unless I really need to fix something for that hard 
link isssue. We'll see ...

Best regards,
Christian Schoenebeck

Re: [PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[Greg Kurz]

On Tue, 20 Oct 2020 01:13:23 +0200
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> Split out walking a directory path to a separate new utility function
> fs_walk_fid() and use that function in fs_mkdir().
> 
> The code difference saved this way is not much, but we'll use that new
> fs_walk_fid() function in the upcoming patches, so it will avoid quite
> some code duplication after all.
> 
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---
>  tests/qtest/virtio-9p-test.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> index c15908f27b..dc724bbb1e 100644
> --- a/tests/qtest/virtio-9p-test.c
> +++ b/tests/qtest/virtio-9p-test.c
> @@ -967,13 +967,12 @@ static void fs_flush_ignored(void *obj, void *data, QGuestAllocator *t_alloc)
>      g_free(wnames[0]);
>  }
>  
> -static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
> -                     const char *path, const char *cname)
> +/* utility function: walk to requested dir and return fid for that dir */
> +static uint32_t fs_walk_fid(void *obj, void *data, QGuestAllocator *t_alloc,
> +                            const char *path)
>  {

Since fs_walk_fid() is a helper function, ie. not passed to qos_add_test(),
any reason to keep the "void *obj, void *data, QGuestAllocator *t_alloc" based
signature ? data and t_alloc aren't used at all and it seems that the function
should rather take a QVirtio9P * directly instead of casting from a void *.

Something like:

static uint32_t fs_walk_fid(QVirtio9P *v9p, const char *path)
{
...
}


Same remark applies to fs_mkdir() which isn't a top level test function
either BTW (sorry for not having spotted this earlier).

>      QVirtio9P *v9p = obj;
> -    alloc = t_alloc;
>      char **wnames;
> -    char *const name = g_strdup(cname);
>      P9Req *req;
>      const uint32_t fid = genfid();
>  
> @@ -983,12 +982,26 @@ static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
>      v9fs_req_wait_for_reply(req, NULL);
>      v9fs_rwalk(req, NULL, NULL);
>  
> +    split_free(&wnames);
> +    return fid;
> +}
> +
> +static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
> +                     const char *path, const char *cname)
> +{
> +    QVirtio9P *v9p = obj;
> +    alloc = t_alloc;
> +    char *const name = g_strdup(cname);
> +    uint32_t fid;
> +    P9Req *req;
> +
> +    fid = fs_walk_fid(v9p, data, t_alloc, path);
> +
>      req = v9fs_tmkdir(v9p, fid, name, 0750, 0, 0);
>      v9fs_req_wait_for_reply(req, NULL);
>      v9fs_rmkdir(req, NULL);
>  
>      g_free(name);
> -    split_free(&wnames);
>  }
>  
>  static void fs_readdir_split_128(void *obj, void *data,

Re: [PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[Christian Schoenebeck]

On Dienstag, 20. Oktober 2020 15:35:36 CEST Greg Kurz wrote:
> On Tue, 20 Oct 2020 01:13:23 +0200
> 
> Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > Split out walking a directory path to a separate new utility function
> > fs_walk_fid() and use that function in fs_mkdir().
> > 
> > The code difference saved this way is not much, but we'll use that new
> > fs_walk_fid() function in the upcoming patches, so it will avoid quite
> > some code duplication after all.
> > 
> > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > ---
> > 
> >  tests/qtest/virtio-9p-test.c | 23 ++++++++++++++++++-----
> >  1 file changed, 18 insertions(+), 5 deletions(-)
> > 
> > diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> > index c15908f27b..dc724bbb1e 100644
> > --- a/tests/qtest/virtio-9p-test.c
> > +++ b/tests/qtest/virtio-9p-test.c
> > @@ -967,13 +967,12 @@ static void fs_flush_ignored(void *obj, void *data,
> > QGuestAllocator *t_alloc)> 
> >      g_free(wnames[0]);
> >  
> >  }
> > 
> > -static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
> > -                     const char *path, const char *cname)
> > +/* utility function: walk to requested dir and return fid for that dir */
> > +static uint32_t fs_walk_fid(void *obj, void *data, QGuestAllocator
> > *t_alloc, +                            const char *path)
> > 
> >  {
> 
> Since fs_walk_fid() is a helper function, ie. not passed to qos_add_test(),
> any reason to keep the "void *obj, void *data, QGuestAllocator *t_alloc"
> based signature ? data and t_alloc aren't used at all and it seems that the
> function should rather take a QVirtio9P * directly instead of casting from
> a void *.
> 
> Something like:
> 
> static uint32_t fs_walk_fid(QVirtio9P *v9p, const char *path)
> {
> ...
> }
> 
> 
> Same remark applies to fs_mkdir() which isn't a top level test function
> either BTW (sorry for not having spotted this earlier).

Good point. Typical case of being copy & waste induced. I'll change that.

Best regards,
Christian Schoenebeck

Re: [PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[Greg Kurz]

On Tue, 20 Oct 2020 15:43:21 +0200
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> On Dienstag, 20. Oktober 2020 15:35:36 CEST Greg Kurz wrote:
> > On Tue, 20 Oct 2020 01:13:23 +0200
> > 
> > Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > > Split out walking a directory path to a separate new utility function
> > > fs_walk_fid() and use that function in fs_mkdir().
> > > 
> > > The code difference saved this way is not much, but we'll use that new
> > > fs_walk_fid() function in the upcoming patches, so it will avoid quite
> > > some code duplication after all.
> > > 
> > > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > > ---
> > > 
> > >  tests/qtest/virtio-9p-test.c | 23 ++++++++++++++++++-----
> > >  1 file changed, 18 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> > > index c15908f27b..dc724bbb1e 100644
> > > --- a/tests/qtest/virtio-9p-test.c
> > > +++ b/tests/qtest/virtio-9p-test.c
> > > @@ -967,13 +967,12 @@ static void fs_flush_ignored(void *obj, void *data,
> > > QGuestAllocator *t_alloc)> 
> > >      g_free(wnames[0]);
> > >  
> > >  }
> > > 
> > > -static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
> > > -                     const char *path, const char *cname)
> > > +/* utility function: walk to requested dir and return fid for that dir */
> > > +static uint32_t fs_walk_fid(void *obj, void *data, QGuestAllocator
> > > *t_alloc, +                            const char *path)
> > > 
> > >  {
> > 
> > Since fs_walk_fid() is a helper function, ie. not passed to qos_add_test(),
> > any reason to keep the "void *obj, void *data, QGuestAllocator *t_alloc"
> > based signature ? data and t_alloc aren't used at all and it seems that the
> > function should rather take a QVirtio9P * directly instead of casting from
> > a void *.
> > 
> > Something like:
> > 
> > static uint32_t fs_walk_fid(QVirtio9P *v9p, const char *path)
> > {
> > ...
> > }
> > 
> > 
> > Same remark applies to fs_mkdir() which isn't a top level test function
> > either BTW (sorry for not having spotted this earlier).
> 
> Good point. Typical case of being copy & waste induced. I'll change that.
> 

Well I guess I haven't set a good exemple by calling fs_attach() everywhere
instead of factoring out an helper in the first place... I have some spare
time, I'll fix that.

> Best regards,
> Christian Schoenebeck
> 
> 

Re: [PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[Greg Kurz]

On Tue, 20 Oct 2020 15:43:21 +0200
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> On Dienstag, 20. Oktober 2020 15:35:36 CEST Greg Kurz wrote:
> > On Tue, 20 Oct 2020 01:13:23 +0200
> > 
> > Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > > Split out walking a directory path to a separate new utility function
> > > fs_walk_fid() and use that function in fs_mkdir().
> > > 
> > > The code difference saved this way is not much, but we'll use that new
> > > fs_walk_fid() function in the upcoming patches, so it will avoid quite
> > > some code duplication after all.
> > > 
> > > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > > ---
> > > 
> > >  tests/qtest/virtio-9p-test.c | 23 ++++++++++++++++++-----
> > >  1 file changed, 18 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> > > index c15908f27b..dc724bbb1e 100644
> > > --- a/tests/qtest/virtio-9p-test.c
> > > +++ b/tests/qtest/virtio-9p-test.c
> > > @@ -967,13 +967,12 @@ static void fs_flush_ignored(void *obj, void *data,
> > > QGuestAllocator *t_alloc)> 
> > >      g_free(wnames[0]);
> > >  
> > >  }
> > > 
> > > -static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
> > > -                     const char *path, const char *cname)
> > > +/* utility function: walk to requested dir and return fid for that dir */
> > > +static uint32_t fs_walk_fid(void *obj, void *data, QGuestAllocator
> > > *t_alloc, +                            const char *path)
> > > 
> > >  {
> > 
> > Since fs_walk_fid() is a helper function, ie. not passed to qos_add_test(),
> > any reason to keep the "void *obj, void *data, QGuestAllocator *t_alloc"
> > based signature ? data and t_alloc aren't used at all and it seems that the
> > function should rather take a QVirtio9P * directly instead of casting from
> > a void *.
> > 
> > Something like:
> > 
> > static uint32_t fs_walk_fid(QVirtio9P *v9p, const char *path)
> > {
> > ...
> > }
> > 
> > 
> > Same remark applies to fs_mkdir() which isn't a top level test function
> > either BTW (sorry for not having spotted this earlier).
> 
> Good point. Typical case of being copy & waste induced. I'll change that.
> 

Since this also affects other patches in this series and this might
have a substantial impact, I'll wait for v2 to review if you don't
mind.

> Best regards,
> Christian Schoenebeck
> 
> 

Re: [PATCH 1/8] tests/9pfs: simplify fs_mkdir()

[Christian Schoenebeck]

On Dienstag, 20. Oktober 2020 20:03:09 CEST Greg Kurz wrote:
> On Tue, 20 Oct 2020 15:43:21 +0200
> 
> Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > On Dienstag, 20. Oktober 2020 15:35:36 CEST Greg Kurz wrote:
> > > On Tue, 20 Oct 2020 01:13:23 +0200
> > > 
> > > Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > > > Split out walking a directory path to a separate new utility function
> > > > fs_walk_fid() and use that function in fs_mkdir().
> > > > 
> > > > The code difference saved this way is not much, but we'll use that new
> > > > fs_walk_fid() function in the upcoming patches, so it will avoid quite
> > > > some code duplication after all.
> > > > 
> > > > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > > > ---
> > > > 
> > > >  tests/qtest/virtio-9p-test.c | 23 ++++++++++++++++++-----
> > > >  1 file changed, 18 insertions(+), 5 deletions(-)
> > > > 
> > > > diff --git a/tests/qtest/virtio-9p-test.c
> > > > b/tests/qtest/virtio-9p-test.c
> > > > index c15908f27b..dc724bbb1e 100644
> > > > --- a/tests/qtest/virtio-9p-test.c
> > > > +++ b/tests/qtest/virtio-9p-test.c
> > > > @@ -967,13 +967,12 @@ static void fs_flush_ignored(void *obj, void
> > > > *data,
> > > > QGuestAllocator *t_alloc)>
> > > > 
> > > >      g_free(wnames[0]);
> > > >  
> > > >  }
> > > > 
> > > > -static void fs_mkdir(void *obj, void *data, QGuestAllocator *t_alloc,
> > > > -                     const char *path, const char *cname)
> > > > +/* utility function: walk to requested dir and return fid for that
> > > > dir */
> > > > +static uint32_t fs_walk_fid(void *obj, void *data, QGuestAllocator
> > > > *t_alloc, +                            const char *path)
> > > > 
> > > >  {
> > > 
> > > Since fs_walk_fid() is a helper function, ie. not passed to
> > > qos_add_test(),
> > > any reason to keep the "void *obj, void *data, QGuestAllocator *t_alloc"
> > > based signature ? data and t_alloc aren't used at all and it seems that
> > > the
> > > function should rather take a QVirtio9P * directly instead of casting
> > > from
> > > a void *.
> > > 
> > > Something like:
> > > 
> > > static uint32_t fs_walk_fid(QVirtio9P *v9p, const char *path)
> > > {
> > > ...
> > > }
> > > 
> > > 
> > > Same remark applies to fs_mkdir() which isn't a top level test function
> > > either BTW (sorry for not having spotted this earlier).
> > 
> > Good point. Typical case of being copy & waste induced. I'll change that.
> 
> Since this also affects other patches in this series and this might
> have a substantial impact, I'll wait for v2 to review if you don't
> mind.

Sure!

There is probably no need to hurry anyway; since these are just test case 
changes, I think it will also be fine if I send the PR during freeze.

You never had any issue with 9p hard links, right? I'm still investigating 
this in parallel. I already can rule out QEMU's sandbox (seccomp) feature, 
even after having disabled the latter that mentioned box is failing any 
link()/linkat() calls. Maybe it's a SELinux issue ...

Best regards,
Christian Schoenebeck