Contributors: 26
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Trond Myklebust |
625 |
37.14% |
16 |
22.54% |
| David Howells |
607 |
36.07% |
10 |
14.08% |
| Al Viro |
167 |
9.92% |
5 |
7.04% |
| Anna Schumaker |
104 |
6.18% |
8 |
11.27% |
| Nicholas Piggin |
27 |
1.60% |
1 |
1.41% |
| Andrew Morton |
24 |
1.43% |
1 |
1.41% |
| Manoj Naik |
22 |
1.31% |
2 |
2.82% |
| Ashish Sangwan |
19 |
1.13% |
1 |
1.41% |
| Christian Brauner |
17 |
1.01% |
4 |
5.63% |
| Linus Torvalds (pre-git) |
15 |
0.89% |
4 |
5.63% |
| Ben Hutchings |
14 |
0.83% |
1 |
1.41% |
| Scott Mayhew |
12 |
0.71% |
3 |
4.23% |
| Benjamin Coddington |
4 |
0.24% |
1 |
1.41% |
| Christoph Hellwig |
3 |
0.18% |
1 |
1.41% |
| Josh Triplett |
3 |
0.18% |
1 |
1.41% |
| Denis V. Lunev |
3 |
0.18% |
1 |
1.41% |
| Kees Cook |
3 |
0.18% |
2 |
2.82% |
| Avi Kivity |
3 |
0.18% |
1 |
1.41% |
| Arjan van de Ven |
2 |
0.12% |
1 |
1.41% |
| Jeff Layton |
2 |
0.12% |
1 |
1.41% |
| Dan Carpenter |
2 |
0.12% |
1 |
1.41% |
| ye xingchen |
1 |
0.06% |
1 |
1.41% |
| Adrian Bunk |
1 |
0.06% |
1 |
1.41% |
| Jan Blunck |
1 |
0.06% |
1 |
1.41% |
| Thomas Gleixner |
1 |
0.06% |
1 |
1.41% |
| Huilong Deng |
1 |
0.06% |
1 |
1.41% |
| Total |
1683 |
|
71 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/nfs/namespace.c
*
* Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
* - Modified by David Howells <dhowells@redhat.com>
*
* NFS namespace
*/
#include <linux/module.h>
#include <linux/dcache.h>
#include <linux/gfp.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/nfs_fs.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/vfs.h>
#include <linux/sunrpc/gss_api.h>
#include "internal.h"
#include "nfs.h"
#define NFSDBG_FACILITY NFSDBG_VFS
static void nfs_expire_automounts(struct work_struct *work);
static LIST_HEAD(nfs_automount_list);
static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
int nfs_mountpoint_expiry_timeout = 500 * HZ;
/*
* nfs_path - reconstruct the path given an arbitrary dentry
* @base - used to return pointer to the end of devname part of path
* @dentry_in - pointer to dentry
* @buffer - result buffer
* @buflen_in - length of buffer
* @flags - options (see below)
*
* Helper function for constructing the server pathname
* by arbitrary hashed dentry.
*
* This is mainly for use in figuring out the path on the
* server side when automounting on top of an existing partition
* and in generating /proc/mounts and friends.
*
* Supported flags:
* NFS_PATH_CANONICAL: ensure there is exactly one slash after
* the original device (export) name
* (if unset, the original name is returned verbatim)
*/
char *nfs_path(char **p, struct dentry *dentry_in, char *buffer,
ssize_t buflen_in, unsigned flags)
{
char *end;
int namelen;
unsigned seq;
const char *base;
struct dentry *dentry;
ssize_t buflen;
rename_retry:
buflen = buflen_in;
dentry = dentry_in;
end = buffer+buflen;
*--end = '\0';
buflen--;
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
while (1) {
spin_lock(&dentry->d_lock);
if (IS_ROOT(dentry))
break;
namelen = dentry->d_name.len;
buflen -= namelen + 1;
if (buflen < 0)
goto Elong_unlock;
end -= namelen;
memcpy(end, dentry->d_name.name, namelen);
*--end = '/';
spin_unlock(&dentry->d_lock);
dentry = dentry->d_parent;
}
if (read_seqretry(&rename_lock, seq)) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
goto rename_retry;
}
if ((flags & NFS_PATH_CANONICAL) && *end != '/') {
if (--buflen < 0) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
goto Elong;
}
*--end = '/';
}
*p = end;
base = dentry->d_fsdata;
if (!base) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
WARN_ON(1);
return end;
}
namelen = strlen(base);
if (*end == '/') {
/* Strip off excess slashes in base string */
while (namelen > 0 && base[namelen - 1] == '/')
namelen--;
}
buflen -= namelen;
if (buflen < 0) {
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
goto Elong;
}
end -= namelen;
memcpy(end, base, namelen);
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
return end;
Elong_unlock:
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
Elong:
return ERR_PTR(-ENAMETOOLONG);
}
EXPORT_SYMBOL_GPL(nfs_path);
/*
* nfs_d_automount - Handle crossing a mountpoint on the server
* @path - The mountpoint
*
* When we encounter a mountpoint on the server, we want to set up
* a mountpoint on the client too, to prevent inode numbers from
* colliding, and to allow "df" to work properly.
* On NFSv4, we also want to allow for the fact that different
* filesystems may be migrated to different servers in a failover
* situation, and that different filesystems may want to use
* different security flavours.
*/
struct vfsmount *nfs_d_automount(struct path *path)
{
struct nfs_fs_context *ctx;
struct fs_context *fc;
struct vfsmount *mnt = ERR_PTR(-ENOMEM);
struct nfs_server *server = NFS_SB(path->dentry->d_sb);
struct nfs_client *client = server->nfs_client;
int timeout = READ_ONCE(nfs_mountpoint_expiry_timeout);
int ret;
if (IS_ROOT(path->dentry))
return ERR_PTR(-ESTALE);
/* Open a new filesystem context, transferring parameters from the
* parent superblock, including the network namespace.
*/
fc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry);
if (IS_ERR(fc))
return ERR_CAST(fc);
ctx = nfs_fc2context(fc);
ctx->clone_data.dentry = path->dentry;
ctx->clone_data.sb = path->dentry->d_sb;
ctx->clone_data.fattr = nfs_alloc_fattr();
if (!ctx->clone_data.fattr)
goto out_fc;
if (fc->net_ns != client->cl_net) {
put_net(fc->net_ns);
fc->net_ns = get_net(client->cl_net);
}
/* for submounts we want the same server; referrals will reassign */
memcpy(&ctx->nfs_server._address, &client->cl_addr, client->cl_addrlen);
ctx->nfs_server.addrlen = client->cl_addrlen;
ctx->nfs_server.port = server->port;
ctx->version = client->rpc_ops->version;
ctx->minorversion = client->cl_minorversion;
ctx->nfs_mod = client->cl_nfs_mod;
__module_get(ctx->nfs_mod->owner);
ret = client->rpc_ops->submount(fc, server);
if (ret < 0) {
mnt = ERR_PTR(ret);
goto out_fc;
}
up_write(&fc->root->d_sb->s_umount);
mnt = vfs_create_mount(fc);
if (IS_ERR(mnt))
goto out_fc;
mntget(mnt); /* prevent immediate expiration */
if (timeout <= 0)
goto out_fc;
mnt_set_expiry(mnt, &nfs_automount_list);
schedule_delayed_work(&nfs_automount_task, timeout);
out_fc:
put_fs_context(fc);
return mnt;
}
static int
nfs_namespace_getattr(struct mnt_idmap *idmap,
const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
if (NFS_FH(d_inode(path->dentry))->size != 0)
return nfs_getattr(idmap, path, stat, request_mask,
query_flags);
generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(path->dentry),
stat);
return 0;
}
static int
nfs_namespace_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
if (NFS_FH(d_inode(dentry))->size != 0)
return nfs_setattr(idmap, dentry, attr);
return -EACCES;
}
const struct inode_operations nfs_mountpoint_inode_operations = {
.getattr = nfs_getattr,
.setattr = nfs_setattr,
};
const struct inode_operations nfs_referral_inode_operations = {
.getattr = nfs_namespace_getattr,
.setattr = nfs_namespace_setattr,
};
static void nfs_expire_automounts(struct work_struct *work)
{
struct list_head *list = &nfs_automount_list;
int timeout = READ_ONCE(nfs_mountpoint_expiry_timeout);
mark_mounts_for_expiry(list);
if (!list_empty(list) && timeout > 0)
schedule_delayed_work(&nfs_automount_task, timeout);
}
void nfs_release_automount_timer(void)
{
if (list_empty(&nfs_automount_list))
cancel_delayed_work(&nfs_automount_task);
}
/**
* nfs_do_submount - set up mountpoint when crossing a filesystem boundary
* @fc: pointer to struct nfs_fs_context
*
*/
int nfs_do_submount(struct fs_context *fc)
{
struct nfs_fs_context *ctx = nfs_fc2context(fc);
struct dentry *dentry = ctx->clone_data.dentry;
struct nfs_server *server;
char *buffer, *p;
int ret;
/* create a new volume representation */
server = ctx->nfs_mod->rpc_ops->clone_server(NFS_SB(ctx->clone_data.sb),
ctx->mntfh,
ctx->clone_data.fattr,
ctx->selected_flavor);
if (IS_ERR(server))
return PTR_ERR(server);
ctx->server = server;
buffer = kmalloc(4096, GFP_USER);
if (!buffer)
return -ENOMEM;
ctx->internal = true;
ctx->clone_data.inherited_bsize = ctx->clone_data.sb->s_blocksize_bits;
p = nfs_devname(dentry, buffer, 4096);
if (IS_ERR(p)) {
nfs_errorf(fc, "NFS: Couldn't determine submount pathname");
ret = PTR_ERR(p);
} else {
ret = vfs_parse_fs_string(fc, "source", p, buffer + 4096 - p);
if (!ret)
ret = vfs_get_tree(fc);
}
kfree(buffer);
return ret;
}
EXPORT_SYMBOL_GPL(nfs_do_submount);
int nfs_submount(struct fs_context *fc, struct nfs_server *server)
{
struct nfs_fs_context *ctx = nfs_fc2context(fc);
struct dentry *dentry = ctx->clone_data.dentry;
struct dentry *parent = dget_parent(dentry);
int err;
/* Look it up again to get its attributes */
err = server->nfs_client->rpc_ops->lookup(d_inode(parent), dentry,
ctx->mntfh, ctx->clone_data.fattr);
dput(parent);
if (err != 0)
return err;
ctx->selected_flavor = server->client->cl_auth->au_flavor;
return nfs_do_submount(fc);
}
EXPORT_SYMBOL_GPL(nfs_submount);
static int param_set_nfs_timeout(const char *val, const struct kernel_param *kp)
{
long num;
int ret;
if (!val)
return -EINVAL;
ret = kstrtol(val, 0, &num);
if (ret)
return -EINVAL;
if (num > 0) {
if (num >= INT_MAX / HZ)
num = INT_MAX;
else
num *= HZ;
*((int *)kp->arg) = num;
if (!list_empty(&nfs_automount_list))
mod_delayed_work(system_wq, &nfs_automount_task, num);
} else {
*((int *)kp->arg) = -1*HZ;
cancel_delayed_work(&nfs_automount_task);
}
return 0;
}
static int param_get_nfs_timeout(char *buffer, const struct kernel_param *kp)
{
long num = *((int *)kp->arg);
if (num > 0) {
if (num >= INT_MAX - (HZ - 1))
num = INT_MAX / HZ;
else
num = (num + (HZ - 1)) / HZ;
} else
num = -1;
return sysfs_emit(buffer, "%li\n", num);
}
static const struct kernel_param_ops param_ops_nfs_timeout = {
.set = param_set_nfs_timeout,
.get = param_get_nfs_timeout,
};
#define param_check_nfs_timeout(name, p) __param_check(name, p, int)
module_param(nfs_mountpoint_expiry_timeout, nfs_timeout, 0644);
MODULE_PARM_DESC(nfs_mountpoint_expiry_timeout,
"Set the NFS automounted mountpoint timeout value (seconds)."
"Values <= 0 turn expiration off.");