[PATCH 3/6] nfsd: make containerise NFSd filesystem

From: Stanislav Kinsbursky
Date: Thu Dec 06 2012 - 10:34:07 EST


This patch makes NFSD file system superblock to be created per net.
This makes possible to get proper network namespace from superblock instead of
using hard-coded "init_net".

Note: NFSd fs super-block holds network namespace. This garantees, that
network namespace won't disappear from underneath of it.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
---
fs/nfsd/nfsctl.c | 46 +++++++++++++++++++++++++++++++++-------------
fs/nfsd/nfssvc.c | 5 ++---
2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7493428..873438f 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -220,6 +220,7 @@ static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
struct sockaddr *sap = (struct sockaddr *)&address;
size_t salen = sizeof(address);
char *fo_path;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;

/* sanity check */
if (size == 0)
@@ -232,7 +233,7 @@ static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
if (qword_get(&buf, fo_path, size) < 0)
return -EINVAL;

- if (rpc_pton(&init_net, fo_path, size, sap, salen) == 0)
+ if (rpc_pton(net, fo_path, size, sap, salen) == 0)
return -EINVAL;

return nlmsvc_unlock_all_by_ip(sap);
@@ -317,6 +318,7 @@ static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
int len;
struct auth_domain *dom;
struct knfsd_fh fh;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;

if (size == 0)
return -EINVAL;
@@ -352,7 +354,7 @@ static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
if (!dom)
return -ENOMEM;

- len = exp_rootfh(&init_net, dom, path, &fh, maxsize);
+ len = exp_rootfh(net, dom, path, &fh, maxsize);
auth_domain_put(dom);
if (len)
return len;
@@ -396,7 +398,7 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size)
{
char *mesg = buf;
int rv;
- struct net *net = &init_net;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;

if (size > 0) {
int newthreads;
@@ -447,7 +449,7 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
int len;
int npools;
int *nthreads;
- struct net *net = &init_net;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;

mutex_lock(&nfsd_mutex);
npools = nfsd_nrpools(net);
@@ -510,7 +512,7 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
unsigned minor;
ssize_t tlen = 0;
char *sep;
- struct net *net = &init_net;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);

if (size>0) {
@@ -792,7 +794,7 @@ static ssize_t __write_ports(struct file *file, char *buf, size_t size,
static ssize_t write_ports(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- struct net *net = &init_net;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;

mutex_lock(&nfsd_mutex);
rv = __write_ports(file, buf, size, net);
@@ -827,7 +829,7 @@ int nfsd_max_blksize;
static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
{
char *mesg = buf;
- struct net *net = &init_net;
+ struct net *net = file->f_dentry->d_sb->s_fs_info;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);

if (size > 0) {
@@ -923,7 +925,8 @@ static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
*/
static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
{
- struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
+ struct net *net = file->f_dentry->d_sb->s_fs_info;
+ struct nfsd_net *nn = net_generic(net, nfsd_net_id);
return nfsd4_write_time(file, buf, size, &nn->nfsd4_lease, nn);
}

@@ -939,7 +942,8 @@ static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
*/
static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
{
- struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
+ struct net *net = file->f_dentry->d_sb->s_fs_info;
+ struct nfsd_net *nn = net_generic(net, nfsd_net_id);
return nfsd4_write_time(file, buf, size, &nn->nfsd4_grace, nn);
}

@@ -995,7 +999,8 @@ static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size,
static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
+ struct net *net = file->f_dentry->d_sb->s_fs_info;
+ struct nfsd_net *nn = net_generic(net, nfsd_net_id);

mutex_lock(&nfsd_mutex);
rv = __write_recoverydir(file, buf, size, nn);
@@ -1037,20 +1042,35 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
#endif
/* last one */ {""}
};
- return simple_fill_super(sb, 0x6e667364, nfsd_files);
+ struct net *net = data;
+ int ret;
+
+ ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
+ if (ret)
+ return ret;
+ sb->s_fs_info = get_net(net);
+ return 0;
}

static struct dentry *nfsd_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- return mount_single(fs_type, flags, data, nfsd_fill_super);
+ return mount_ns(fs_type, flags, current->nsproxy->net_ns, nfsd_fill_super);
+}
+
+static void nfsd_umount(struct super_block *sb)
+{
+ struct net *net = sb->s_fs_info;
+
+ kill_litter_super(sb);
+ put_net(net);
}

static struct file_system_type nfsd_fs_type = {
.owner = THIS_MODULE,
.name = "nfsd",
.mount = nfsd_mount,
- .kill_sb = kill_litter_super,
+ .kill_sb = nfsd_umount,
};

#ifdef CONFIG_PROC_FS
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 177bb60..bf1c4d3 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -734,8 +734,7 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
int nfsd_pool_stats_open(struct inode *inode, struct file *file)
{
int ret;
- struct net *net = &init_net;
- struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+ struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);

mutex_lock(&nfsd_mutex);
if (nn->nfsd_serv == NULL) {
@@ -752,7 +751,7 @@ int nfsd_pool_stats_open(struct inode *inode, struct file *file)
int nfsd_pool_stats_release(struct inode *inode, struct file *file)
{
int ret = seq_release(inode, file);
- struct net *net = &init_net;
+ struct net *net = inode->i_sb->s_fs_info;

mutex_lock(&nfsd_mutex);
/* this function really, really should have been called svc_put() */

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