diff options
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/inode.c | 270 |
1 files changed, 267 insertions, 3 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index ebdab885c47..0d8302e59d6 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -36,6 +36,8 @@ #include <linux/mount.h> #include <linux/nfs_idmap.h> #include <linux/vfs.h> +#include <linux/inet.h> +#include <linux/nfs_xdr.h> #include <asm/system.h> #include <asm/uaccess.h> @@ -1714,6 +1716,10 @@ struct nfs_clone_mount { const struct dentry *dentry; struct nfs_fh *fh; struct nfs_fattr *fattr; + char *hostname; + char *mnt_path; + struct sockaddr_in *addr; + rpc_authflavor_t authflavor; }; static struct super_block *nfs_clone_generic_sb(struct nfs_clone_mount *data, @@ -1724,17 +1730,19 @@ static struct super_block *nfs_clone_generic_sb(struct nfs_clone_mount *data, struct nfs_server *parent = NFS_SB(data->sb); struct super_block *sb = ERR_PTR(-EINVAL); void *err = ERR_PTR(-ENOMEM); + char *hostname; int len; server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL); if (server == NULL) goto out_err; memcpy(server, parent, sizeof(*server)); - len = strlen(parent->hostname) + 1; + hostname = (data->hostname != NULL) ? data->hostname : parent->hostname; + len = strlen(hostname) + 1; server->hostname = kmalloc(len, GFP_KERNEL); if (server->hostname == NULL) goto free_server; - memcpy(server->hostname, parent->hostname, len); + memcpy(server->hostname, hostname, len); if (rpciod_up() != 0) goto free_hostname; @@ -2458,7 +2466,8 @@ static inline void unregister_nfs4fs(void) nfs_unregister_sysctl(); } #else -#define nfs4_clone_client(a,b) ERR_PTR(-EINVAL) +#define nfs4_fill_sb(a,b) ERR_PTR(-EINVAL) +#define nfs4_fill_super(a,b) ERR_PTR(-EINVAL) #define nfs4_init_once(nfsi) \ do { } while (0) #define register_nfs4fs() (0) @@ -2521,6 +2530,261 @@ out: return mnt; } +/* Check if fs_root is valid */ +static inline char *nfs4_pathname_string(struct nfs4_pathname *pathname, char *buffer, ssize_t buflen) +{ + char *end = buffer + buflen; + int n; + + *--end = '\0'; + buflen--; + + n = pathname->ncomponents; + while (--n >= 0) { + struct nfs4_string *component = &pathname->components[n]; + buflen -= component->len + 1; + if (buflen < 0) + goto Elong; + end -= component->len; + memcpy(end, component->data, component->len); + *--end = '/'; + } + return end; +Elong: + return ERR_PTR(-ENAMETOOLONG); +} + +/* Check if the string represents a "valid" IPv4 address */ +static inline int valid_ipaddr4(const char *buf) +{ + int rc, count, in[4]; + + rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); + if (rc != 4) + return -EINVAL; + for (count = 0; count < 4; count++) { + if (in[count] > 255) + return -EINVAL; + } + return 0; +} + +static struct super_block *nfs4_referral_sb(struct nfs_server *server, struct nfs_clone_mount *data) +{ + struct super_block *sb = ERR_PTR(-ENOMEM); + int len; + + len = strlen(data->mnt_path) + 1; + server->mnt_path = kmalloc(len, GFP_KERNEL); + if (server->mnt_path == NULL) + goto err; + memcpy(server->mnt_path, data->mnt_path, len); + memcpy(&server->addr, data->addr, sizeof(struct sockaddr_in)); + + sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server); + if (IS_ERR(sb) || sb->s_root) + goto free_path; + return sb; +free_path: + kfree(server->mnt_path); +err: + server->mnt_path = NULL; + return sb; +} + +static struct nfs_server *nfs4_referral_server(struct super_block *sb, struct nfs_clone_mount *data) +{ + struct nfs_server *server = NFS_SB(sb); + struct rpc_timeout timeparms; + int proto, timeo, retrans; + void *err; + + proto = IPPROTO_TCP; + /* Since we are following a referral and there may be alternatives, + set the timeouts and retries to low values */ + timeo = 2; + retrans = 1; + nfs_init_timeout_values(&timeparms, proto, timeo, retrans); + + server->client = nfs4_create_client(server, &timeparms, proto, data->authflavor); + if (IS_ERR((err = server->client))) + goto out_err; + + sb->s_time_gran = 1; + sb->s_op = &nfs4_sops; + err = ERR_PTR(nfs_sb_init(sb, data->authflavor)); + if (!IS_ERR(err)) + return server; +out_err: + return (struct nfs_server *)err; +} + +static struct super_block *nfs_referral_nfs4_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *raw_data) +{ + struct nfs_clone_mount *data = raw_data; + return nfs_clone_generic_sb(data, nfs4_referral_sb, nfs4_referral_server); +} + +static struct file_system_type nfs_referral_nfs4_fs_type = { + .owner = THIS_MODULE, + .name = "nfs4", + .get_sb = nfs_referral_nfs4_sb, + .kill_sb = nfs4_kill_super, + .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, +}; + +/** + * nfs_follow_referral - set up mountpoint when hitting a referral on moved error + * @mnt_parent - mountpoint of parent directory + * @dentry - parent directory + * @fspath - fs path returned in fs_locations + * @mntpath - mount path to new server + * @hostname - hostname of new server + * @addr - host addr of new server + * + */ +struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent, + const struct dentry *dentry, 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, *page2; + char *path, *fs_path; + char *devname; + int loc, s; + + if (locations == NULL || locations->nlocations <= 0) + goto out; + + dprintk("%s: referral at %s/%s\n", __FUNCTION__, + dentry->d_parent->d_name.name, dentry->d_name.name); + + /* Ensure fs path is a prefix of current dentry path */ + page = (char *) __get_free_page(GFP_USER); + if (page == NULL) + goto out; + page2 = (char *) __get_free_page(GFP_USER); + if (page2 == NULL) + goto out; + + path = nfs4_path(dentry, page, PAGE_SIZE); + if (IS_ERR(path)) + goto out_free; + + fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE); + if (IS_ERR(fs_path)) + goto out_free; + + if (strncmp(path, fs_path, strlen(fs_path)) != 0) { + dprintk("%s: path %s does not begin with fsroot %s\n", __FUNCTION__, path, fs_path); + goto out_free; + } + + devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE); + if (IS_ERR(devname)) { + mnt = (struct vfsmount *)devname; + goto out_free; + } + + loc = 0; + while (loc < locations->nlocations && IS_ERR(mnt)) { + 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 = {}; + + 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); + addr.sin_family = AF_INET; + addr.sin_port = htons(NFS_PORT); + mountdata.addr = &addr; + + mnt = vfs_kern_mount(&nfs_referral_nfs4_fs_type, 0, devname, &mountdata); + if (!IS_ERR(mnt)) { + break; + } + s++; + } + loc++; + } + +out_free: + free_page((unsigned long)page); + free_page((unsigned long)page2); +out: + dprintk("%s: done\n", __FUNCTION__); + 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(-ENOENT); + struct dentry *parent; + struct nfs4_fs_locations *fs_locations = NULL; + struct page *page; + int err; + + /* BUG_ON(IS_ROOT(dentry)); */ + dprintk("%s: enter\n", __FUNCTION__); + + 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 */ + parent = dget_parent(dentry); + dprintk("%s: getting locations for %s/%s\n", __FUNCTION__, parent->d_name.name, dentry->d_name.name); + err = nfs4_proc_fs_locations(parent->d_inode, dentry, 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", __FUNCTION__); + return mnt; +} + extern int nfs_init_nfspagecache(void); extern void nfs_destroy_nfspagecache(void); extern int nfs_init_readpagecache(void); 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