virtio-9p: Add P9_TWALK support

Implement P9_TWALK support.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2010-04-29 17:44:54 +05:30
parent 4da7d3fa2d
commit ff5e54c987

View File

@ -953,11 +953,180 @@ out:
qemu_free(vs);
}
typedef struct V9fsWalkState {
V9fsPDU *pdu;
size_t offset;
int16_t nwnames;
int name_idx;
V9fsQID *qids;
V9fsFidState *fidp;
V9fsFidState *newfidp;
V9fsString path;
V9fsString *wnames;
struct stat stbuf;
} V9fsWalkState;
static void v9fs_walk_complete(V9fsState *s, V9fsWalkState *vs, int err)
{
complete_pdu(s, vs->pdu, err);
if (vs->nwnames) {
for (vs->name_idx = 0; vs->name_idx < vs->nwnames; vs->name_idx++) {
v9fs_string_free(&vs->wnames[vs->name_idx]);
}
qemu_free(vs->wnames);
qemu_free(vs->qids);
}
}
static void v9fs_walk_marshal(V9fsWalkState *vs)
{
int i;
vs->offset = 7;
vs->offset += pdu_marshal(vs->pdu, vs->offset, "w", vs->nwnames);
for (i = 0; i < vs->nwnames; i++) {
vs->offset += pdu_marshal(vs->pdu, vs->offset, "Q", &vs->qids[i]);
}
}
static void v9fs_walk_post_newfid_lstat(V9fsState *s, V9fsWalkState *vs,
int err)
{
if (err == -1) {
free_fid(s, vs->newfidp->fid);
v9fs_string_free(&vs->path);
err = -ENOENT;
goto out;
}
stat_to_qid(&vs->stbuf, &vs->qids[vs->name_idx]);
vs->name_idx++;
if (vs->name_idx < vs->nwnames) {
v9fs_string_sprintf(&vs->path, "%s/%s", vs->newfidp->path.data,
vs->wnames[vs->name_idx].data);
v9fs_string_copy(&vs->newfidp->path, &vs->path);
err = v9fs_do_lstat(s, &vs->newfidp->path, &vs->stbuf);
v9fs_walk_post_newfid_lstat(s, vs, err);
return;
}
v9fs_string_free(&vs->path);
v9fs_walk_marshal(vs);
err = vs->offset;
out:
v9fs_walk_complete(s, vs, err);
}
static void v9fs_walk_post_oldfid_lstat(V9fsState *s, V9fsWalkState *vs,
int err)
{
if (err == -1) {
v9fs_string_free(&vs->path);
err = -ENOENT;
goto out;
}
stat_to_qid(&vs->stbuf, &vs->qids[vs->name_idx]);
vs->name_idx++;
if (vs->name_idx < vs->nwnames) {
v9fs_string_sprintf(&vs->path, "%s/%s",
vs->fidp->path.data, vs->wnames[vs->name_idx].data);
v9fs_string_copy(&vs->fidp->path, &vs->path);
err = v9fs_do_lstat(s, &vs->fidp->path, &vs->stbuf);
v9fs_walk_post_oldfid_lstat(s, vs, err);
return;
}
v9fs_string_free(&vs->path);
v9fs_walk_marshal(vs);
err = vs->offset;
out:
v9fs_walk_complete(s, vs, err);
}
static void v9fs_walk(V9fsState *s, V9fsPDU *pdu)
{
if (debug_9p_pdu) {
pprint_pdu(pdu);
int32_t fid, newfid;
V9fsWalkState *vs;
int err = 0;
int i;
vs = qemu_malloc(sizeof(*vs));
vs->pdu = pdu;
vs->wnames = NULL;
vs->qids = NULL;
vs->offset = 7;
vs->offset += pdu_unmarshal(vs->pdu, vs->offset, "ddw", &fid,
&newfid, &vs->nwnames);
if (vs->nwnames) {
vs->wnames = qemu_mallocz(sizeof(vs->wnames[0]) * vs->nwnames);
vs->qids = qemu_mallocz(sizeof(vs->qids[0]) * vs->nwnames);
for (i = 0; i < vs->nwnames; i++) {
vs->offset += pdu_unmarshal(vs->pdu, vs->offset, "s",
&vs->wnames[i]);
}
}
vs->fidp = lookup_fid(s, fid);
if (vs->fidp == NULL) {
err = -ENOENT;
goto out;
}
/* FIXME: is this really valid? */
if (fid == newfid) {
BUG_ON(vs->fidp->fd != -1);
BUG_ON(vs->fidp->dir);
v9fs_string_init(&vs->path);
vs->name_idx = 0;
if (vs->name_idx < vs->nwnames) {
v9fs_string_sprintf(&vs->path, "%s/%s",
vs->fidp->path.data, vs->wnames[vs->name_idx].data);
v9fs_string_copy(&vs->fidp->path, &vs->path);
err = v9fs_do_lstat(s, &vs->fidp->path, &vs->stbuf);
v9fs_walk_post_oldfid_lstat(s, vs, err);
return;
}
} else {
vs->newfidp = alloc_fid(s, newfid);
if (vs->newfidp == NULL) {
err = -EINVAL;
goto out;
}
vs->newfidp->uid = vs->fidp->uid;
v9fs_string_init(&vs->path);
vs->name_idx = 0;
v9fs_string_copy(&vs->newfidp->path, &vs->fidp->path);
if (vs->name_idx < vs->nwnames) {
v9fs_string_sprintf(&vs->path, "%s/%s", vs->newfidp->path.data,
vs->wnames[vs->name_idx].data);
v9fs_string_copy(&vs->newfidp->path, &vs->path);
err = v9fs_do_lstat(s, &vs->newfidp->path, &vs->stbuf);
v9fs_walk_post_newfid_lstat(s, vs, err);
return;
}
}
v9fs_walk_marshal(vs);
err = vs->offset;
out:
v9fs_walk_complete(s, vs, err);
}
static void v9fs_clunk(V9fsState *s, V9fsPDU *pdu)