2 * linux/fs/nfs/nfs4namespace.c
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
5 * - Modified by David Howells <dhowells@redhat.com>
10 #include <linux/dcache.h>
11 #include <linux/mount.h>
12 #include <linux/namei.h>
13 #include <linux/nfs_fs.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/sunrpc/clnt.h>
17 #include <linux/vfs.h>
18 #include <linux/inet.h>
21 #include "dns_resolve.h"
23 #define NFSDBG_FACILITY NFSDBG_VFS
26 * Convert the NFSv4 pathname components into a standard posix path.
28 * Note that the resulting string will be placed at the end of the buffer
30 static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
31 char *buffer, ssize_t buflen)
33 char *end = buffer + buflen;
39 n = pathname->ncomponents;
41 const struct nfs4_string *component = &pathname->components[n];
42 buflen -= component->len + 1;
45 end -= component->len;
46 memcpy(end, component->data, component->len);
51 return ERR_PTR(-ENAMETOOLONG);
55 * Determine the mount path as a string
57 static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
60 char *path = nfs_path(&limit, dentry, buffer, buflen);
62 char *colon = strchr(path, ':');
63 if (colon && colon < limit)
70 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
71 * believe to be the server path to this dentry
73 static int nfs4_validate_fspath(struct dentry *dentry,
74 const struct nfs4_fs_locations *locations,
75 char *page, char *page2)
77 const char *path, *fs_path;
79 path = nfs4_path(dentry, page, PAGE_SIZE);
83 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
85 return PTR_ERR(fs_path);
87 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
88 dprintk("%s: path %s does not begin with fsroot %s\n",
89 __func__, path, fs_path);
96 static size_t nfs_parse_server_name(char *string, size_t len,
97 struct sockaddr *sa, size_t salen)
101 ret = rpc_pton(string, len, sa, salen);
103 ret = nfs_dns_resolve_name(string, len, sa, salen);
110 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
111 char *page, char *page2,
112 const struct nfs4_fs_location *location)
114 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
115 struct vfsmount *mnt = ERR_PTR(-ENOENT);
117 unsigned int maxbuflen;
120 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
121 if (IS_ERR(mnt_path))
122 return ERR_CAST(mnt_path);
123 mountdata->mnt_path = mnt_path;
124 maxbuflen = mnt_path - 1 - page2;
126 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
127 if (mountdata->addr == NULL)
128 return ERR_PTR(-ENOMEM);
130 for (s = 0; s < location->nservers; s++) {
131 const struct nfs4_string *buf = &location->servers[s];
133 if (buf->len <= 0 || buf->len >= maxbuflen)
136 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
139 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
140 mountdata->addr, addr_bufsize);
141 if (mountdata->addrlen == 0)
144 rpc_set_port(mountdata->addr, NFS_PORT);
146 memcpy(page2, buf->data, buf->len);
147 page2[buf->len] = '\0';
148 mountdata->hostname = page2;
150 snprintf(page, PAGE_SIZE, "%s:%s",
152 mountdata->mnt_path);
154 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
158 kfree(mountdata->addr);
163 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
164 * @dentry - parent directory
165 * @locations - array of NFSv4 server location information
168 static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
169 const struct nfs4_fs_locations *locations)
171 struct vfsmount *mnt = ERR_PTR(-ENOENT);
172 struct nfs_clone_mount mountdata = {
175 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
177 char *page = NULL, *page2 = NULL;
180 if (locations == NULL || locations->nlocations <= 0)
183 dprintk("%s: referral at %s/%s\n", __func__,
184 dentry->d_parent->d_name.name, dentry->d_name.name);
186 page = (char *) __get_free_page(GFP_USER);
190 page2 = (char *) __get_free_page(GFP_USER);
194 /* Ensure fs path is a prefix of current dentry path */
195 error = nfs4_validate_fspath(dentry, locations, page, page2);
197 mnt = ERR_PTR(error);
201 for (loc = 0; loc < locations->nlocations; loc++) {
202 const struct nfs4_fs_location *location = &locations->locations[loc];
204 if (location == NULL || location->nservers <= 0 ||
205 location->rootpath.ncomponents == 0)
208 mnt = try_location(&mountdata, page, page2, location);
214 free_page((unsigned long) page);
215 free_page((unsigned long) page2);
216 dprintk("%s: done\n", __func__);
221 * nfs_do_refmount - handle crossing a referral on server
222 * @dentry - dentry of referral
225 struct vfsmount *nfs_do_refmount(struct dentry *dentry)
227 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
228 struct dentry *parent;
229 struct nfs4_fs_locations *fs_locations = NULL;
233 /* BUG_ON(IS_ROOT(dentry)); */
234 dprintk("%s: enter\n", __func__);
236 page = alloc_page(GFP_KERNEL);
240 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
241 if (fs_locations == NULL)
245 mnt = ERR_PTR(-ENOENT);
247 parent = dget_parent(dentry);
248 dprintk("%s: getting locations for %s/%s\n",
249 __func__, parent->d_name.name, dentry->d_name.name);
251 err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
254 fs_locations->nlocations <= 0 ||
255 fs_locations->fs_path.ncomponents <= 0)
258 mnt = nfs_follow_referral(dentry, fs_locations);
263 dprintk("%s: done\n", __func__);