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authorManoj Naik <manoj@almaden.ibm.com>2006-06-09 09:34:28 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-09 09:34:28 -0400
commit9cdb3883c38f883436a84c2353a4cf964ff890a2 (patch)
tree7961aebf94c66d7d55bb6e7c715e99d28ad3ab9d /fs/nfs
parent61f5164cab1f6fdf06871ea9d60fe2f912184078 (diff)
NFSv4: Ensure client submounts when following a referral
Set up mountpoint when hitting a referral on moved error by getting fs_locations. Signed-off-by: Manoj Naik <manoj@almaden.ibm.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/inode.c270
1 files changed, 267 insertions, 3 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ebdab885c475..0d8302e59d69 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);