static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
char *page, char *page2,
const struct nfs4_fs_location *location)
{
const size_t addr_bufsize = sizeof(struct sockaddr_storage);
struct vfsmount *mnt = ERR_PTR(-ENOENT);
char *mnt_path;
unsigned int maxbuflen;
unsigned int s;
mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
if (IS_ERR(mnt_path))
return ERR_CAST(mnt_path);
mountdata->mnt_path = mnt_path;
maxbuflen = mnt_path - 1 - page2;
mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
if (mountdata->addr == NULL)
return ERR_PTR(-ENOMEM);
for (s = 0; s < location->nservers; s++) {
const struct nfs4_string *buf = &location->servers[s];
if (buf->len <= 0 || buf->len >= maxbuflen)
continue;
if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
continue;
mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
mountdata->addr, addr_bufsize,
NFS_SB(mountdata->sb));
if (mountdata->addrlen == 0)
continue;
rpc_set_port(mountdata->addr, NFS_PORT);
memcpy(page2, buf->data, buf->len);
page2[buf->len] = '\0';
mountdata->hostname = page2;
snprintf(page, PAGE_SIZE, "%s:%s",
mountdata->hostname,
mountdata->mnt_path);
mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
if (!IS_ERR(mnt))
break;
}
kfree(mountdata->addr);
return mnt;
}
/*
* Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
* believe to be the server path to this dentry
*/
static int nfs4_validate_fspath(struct dentry *dentry,
const struct nfs4_fs_locations *locations,
char *page, char *page2)
{
const char *path, *fs_path;
path = nfs4_path(dentry, page, PAGE_SIZE);
if (IS_ERR(path))
return PTR_ERR(path);
fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
if (IS_ERR(fs_path))
return PTR_ERR(fs_path);
if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
dprintk("%s: path %s does not begin with fsroot %s\n",
__func__, path, fs_path);
return -ENOENT;
}
return 0;
}
/**
* nfs_follow_referral - set up mountpoint when hitting a referral on moved error
* @mnt_parent - mountpoint of parent directory
* @dentry - parent directory
* @locations - array of NFSv4 server location information
*
*/
static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
const struct nfs4_fs_locations *locations)
{
struct vfsmount *mnt = ERR_PTR(-ENOENT);
struct nfs_clone_mount mountdata = {
.sb = mnt_parent->mnt_sb,
.dentry = dentry,
.authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
};
char *page = NULL, *page2 = NULL;
unsigned int s;
int loc, error;
if (locations == NULL || locations->nlocations <= 0)
goto out;
dprintk("%s: referral at %s/%s\n", __func__,
dentry->d_parent->d_name.name, dentry->d_name.name);
page = (char *) __get_free_page(GFP_USER);
if (!page)
goto out;
page2 = (char *) __get_free_page(GFP_USER);
if (!page2)
goto out;
/* Ensure fs path is a prefix of current dentry path */
error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
if (error < 0) {
mnt = ERR_PTR(error);
goto out;
}
loc = 0;
while (loc < locations->nlocations && IS_ERR(mnt)) {
const struct nfs4_fs_location *location = &locations->locations[loc];
char *mnt_path;
if (location == NULL || location->nservers <= 0 ||
location->rootpath.ncomponents == 0) {
loc++;
continue;
}
mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
if (IS_ERR(mnt_path)) {
loc++;
continue;
}
mountdata.mnt_path = mnt_path;
s = 0;
while (s < location->nservers) {
struct sockaddr_in addr = {
.sin_family = AF_INET,
.sin_port = htons(NFS_PORT),
};
if (location->servers[s].len <= 0 ||
valid_ipaddr4(location->servers[s].data) < 0) {
s++;
continue;
}
mountdata.hostname = location->servers[s].data;
addr.sin_addr.s_addr = in_aton(mountdata.hostname),
mountdata.addr = (struct sockaddr *)&addr;
mountdata.addrlen = sizeof(addr);
snprintf(page, PAGE_SIZE, "%s:%s",
mountdata.hostname,
mountdata.mnt_path);
mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, &mountdata);
if (!IS_ERR(mnt)) {
break;
}
s++;
}
loc++;
}
out:
free_page((unsigned long) page);
free_page((unsigned long) page2);
dprintk("%s: done\n", __func__);
return mnt;
}
/*
* nfs_do_refmount - handle crossing a referral on server
* @dentry - dentry of referral
* @nd - nameidata info
*
*/
struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
{
struct vfsmount *mnt = ERR_PTR(-ENOMEM);
struct dentry *parent;
struct nfs4_fs_locations *fs_locations = NULL;
struct page *page;
int err;
/* BUG_ON(IS_ROOT(dentry)); */
dprintk("%s: enter\n", __func__);
page = alloc_page(GFP_KERNEL);
if (page == NULL)
goto out;
fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
if (fs_locations == NULL)
goto out_free;
/* Get locations */
mnt = ERR_PTR(-ENOENT);
parent = dget_parent(dentry);
dprintk("%s: getting locations for %s/%s\n",
__func__, parent->d_name.name, dentry->d_name.name);
err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
dput(parent);
if (err != 0 ||
fs_locations->nlocations <= 0 ||
fs_locations->fs_path.ncomponents <= 0)
goto out_free;
mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
out_free:
__free_page(page);
kfree(fs_locations);
out:
dprintk("%s: done\n", __func__);
return mnt;
}
