[virtio-9p] Define and implement TSYMLINK for 9P2000.L
This patch implements creating a symlink for TSYMLINK request
and responds with RSYMLINK. In the case of error, we return RERROR.
SYNOPSIS
size[4] Tsymlink tag[2] fid[4] name[s] symtgt[s] gid[4]
size[4] Rsymlink tag[2] qid[13]
DESCRIPTION
Create a symbolic link named 'name' pointing to 'symtgt'.
gid represents the effective group id of the caller.
The permissions of a symbolic link are irrelevant hence it is omitted
from the protocol.
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
diff --git a/hw/virtio-9p-debug.c b/hw/virtio-9p-debug.c
index 2e61e9d..54179aa 100644
--- a/hw/virtio-9p-debug.c
+++ b/hw/virtio-9p-debug.c
@@ -464,6 +464,17 @@
pprint_qid(pdu, 1, &offset, "qid");
pprint_int32(pdu, 1, &offset, ", iounit");
break;
+ case P9_TSYMLINK:
+ fprintf(llogfile, "TSYMLINK: (");
+ pprint_int32(pdu, 0, &offset, "fid");
+ pprint_str(pdu, 0, &offset, ", name");
+ pprint_str(pdu, 0, &offset, ", symname");
+ pprint_int32(pdu, 0, &offset, ", gid");
+ break;
+ case P9_RSYMLINK:
+ fprintf(llogfile, "RSYMLINK: (");
+ pprint_qid(pdu, 1, &offset, "qid");
+ break;
case P9_TREAD:
fprintf(llogfile, "TREAD: (");
pprint_int32(pdu, 0, &offset, "fid");
diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index d1c3cf8..1036b49 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -200,15 +200,16 @@
return s->ops->open2(&s->ctx, vs->fullname.data, flags, &cred);
}
-static int v9fs_do_symlink(V9fsState *s, V9fsCreateState *vs)
+static int v9fs_do_symlink(V9fsState *s, V9fsFidState *fidp,
+ const char *oldpath, const char *newpath, gid_t gid)
{
FsCred cred;
cred_init(&cred);
- cred.fc_uid = vs->fidp->uid;
- cred.fc_mode = vs->perm | 0777;
+ cred.fc_uid = fidp->uid;
+ cred.fc_gid = gid;
+ cred.fc_mode = 0777;
- return s->ops->symlink(&s->ctx, vs->extension.data, vs->fullname.data,
- &cred);
+ return s->ops->symlink(&s->ctx, oldpath, newpath, &cred);
}
static int v9fs_do_link(V9fsState *s, V9fsString *oldpath, V9fsString *newpath)
@@ -2212,7 +2213,8 @@
err = v9fs_do_mkdir(s, vs);
v9fs_create_post_mkdir(s, vs, err);
} else if (vs->perm & P9_STAT_MODE_SYMLINK) {
- err = v9fs_do_symlink(s, vs);
+ err = v9fs_do_symlink(s, vs->fidp, vs->extension.data,
+ vs->fullname.data, -1);
v9fs_create_post_perms(s, vs, err);
} else if (vs->perm & P9_STAT_MODE_LINK) {
int32_t nfid = atoi(vs->extension.data);
@@ -2301,6 +2303,69 @@
qemu_free(vs);
}
+static void v9fs_post_symlink(V9fsState *s, V9fsSymlinkState *vs, int err)
+{
+ if (err == 0) {
+ stat_to_qid(&vs->stbuf, &vs->qid);
+ vs->offset += pdu_marshal(vs->pdu, vs->offset, "Q", &vs->qid);
+ err = vs->offset;
+ } else {
+ err = -errno;
+ }
+ complete_pdu(s, vs->pdu, err);
+ v9fs_string_free(&vs->name);
+ v9fs_string_free(&vs->symname);
+ v9fs_string_free(&vs->fullname);
+ qemu_free(vs);
+}
+
+static void v9fs_symlink_post_do_symlink(V9fsState *s, V9fsSymlinkState *vs,
+ int err)
+{
+ if (err) {
+ goto out;
+ }
+ err = v9fs_do_lstat(s, &vs->fullname, &vs->stbuf);
+out:
+ v9fs_post_symlink(s, vs, err);
+}
+
+static void v9fs_symlink(V9fsState *s, V9fsPDU *pdu)
+{
+ int32_t dfid;
+ V9fsSymlinkState *vs;
+ int err = 0;
+ gid_t gid;
+
+ vs = qemu_malloc(sizeof(*vs));
+ vs->pdu = pdu;
+ vs->offset = 7;
+
+ v9fs_string_init(&vs->fullname);
+
+ pdu_unmarshal(vs->pdu, vs->offset, "dssd", &dfid, &vs->name,
+ &vs->symname, &gid);
+
+ vs->dfidp = lookup_fid(s, dfid);
+ if (vs->dfidp == NULL) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ v9fs_string_sprintf(&vs->fullname, "%s/%s", vs->dfidp->path.data,
+ vs->name.data);
+ err = v9fs_do_symlink(s, vs->dfidp, vs->symname.data,
+ vs->fullname.data, gid);
+ v9fs_symlink_post_do_symlink(s, vs, err);
+ return;
+
+out:
+ complete_pdu(s, vs->pdu, err);
+ v9fs_string_free(&vs->name);
+ v9fs_string_free(&vs->symname);
+ qemu_free(vs);
+}
+
static void v9fs_flush(V9fsState *s, V9fsPDU *pdu)
{
/* A nop call with no return */
@@ -2718,6 +2783,7 @@
#endif
[P9_TFLUSH] = v9fs_flush,
[P9_TLINK] = v9fs_link,
+ [P9_TSYMLINK] = v9fs_symlink,
[P9_TCREATE] = v9fs_create,
[P9_TWRITE] = v9fs_write,
[P9_TWSTAT] = v9fs_wstat,
diff --git a/hw/virtio-9p.h b/hw/virtio-9p.h
index d48776f..3671863 100644
--- a/hw/virtio-9p.h
+++ b/hw/virtio-9p.h
@@ -15,6 +15,8 @@
enum {
P9_TSTATFS = 8,
P9_RSTATFS,
+ P9_TSYMLINK = 16,
+ P9_RSYMLINK,
P9_TGETATTR = 24,
P9_RGETATTR,
P9_TSETATTR = 26,
@@ -294,6 +296,18 @@
V9fsString nname;
} V9fsWstatState;
+typedef struct V9fsSymlinkState
+{
+ V9fsPDU *pdu;
+ size_t offset;
+ V9fsString name;
+ V9fsString symname;
+ V9fsString fullname;
+ V9fsFidState *dfidp;
+ V9fsQID qid;
+ struct stat stbuf;
+} V9fsSymlinkState;
+
typedef struct V9fsIattr
{
int32_t valid;
