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-rw-r--r--fs/Makefile2
-rw-r--r--fs/internal.h5
-rw-r--r--fs/mount.h3
-rw-r--r--fs/namespace.c51
-rw-r--r--fs/nsfs.c161
-rw-r--r--fs/proc/inode.c10
-rw-r--r--fs/proc/internal.h2
-rw-r--r--fs/proc/namespaces.c153
8 files changed, 207 insertions, 180 deletions
diff --git a/fs/Makefile b/fs/Makefile
index da0bbb456d3f..bedff48e8fdc 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -11,7 +11,7 @@ obj-y := open.o read_write.o file_table.o super.o \
attr.o bad_inode.o file.o filesystems.o namespace.o \
seq_file.o xattr.o libfs.o fs-writeback.o \
pnode.o splice.o sync.o utimes.o \
- stack.o fs_struct.o statfs.o fs_pin.o
+ stack.o fs_struct.o statfs.o fs_pin.o nsfs.o
ifeq ($(CONFIG_BLOCK),y)
obj-y += buffer.o block_dev.o direct-io.o mpage.o
diff --git a/fs/internal.h b/fs/internal.h
index 757ba2abf21e..e9a61fe67575 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -147,3 +147,8 @@ extern const struct file_operations pipefifo_fops;
*/
extern void sb_pin_kill(struct super_block *sb);
extern void mnt_pin_kill(struct mount *m);
+
+/*
+ * fs/nsfs.c
+ */
+extern struct dentry_operations ns_dentry_operations;
diff --git a/fs/mount.h b/fs/mount.h
index f82c62840905..0ad6f760ce52 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -1,10 +1,11 @@
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/poll.h>
+#include <linux/ns_common.h>
struct mnt_namespace {
atomic_t count;
- unsigned int proc_inum;
+ struct ns_common ns;
struct mount * root;
struct list_head list;
struct user_namespace *user_ns;
diff --git a/fs/namespace.c b/fs/namespace.c
index 5b66b2b3624d..30df6e7dd807 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1569,17 +1569,13 @@ SYSCALL_DEFINE1(oldumount, char __user *, name)
static bool is_mnt_ns_file(struct dentry *dentry)
{
/* Is this a proxy for a mount namespace? */
- struct inode *inode = dentry->d_inode;
- struct proc_ns *ei;
-
- if (!proc_ns_inode(inode))
- return false;
-
- ei = get_proc_ns(inode);
- if (ei->ns_ops != &mntns_operations)
- return false;
+ return dentry->d_op == &ns_dentry_operations &&
+ dentry->d_fsdata == &mntns_operations;
+}
- return true;
+struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
+{
+ return container_of(ns, struct mnt_namespace, ns);
}
static bool mnt_ns_loop(struct dentry *dentry)
@@ -1591,7 +1587,7 @@ static bool mnt_ns_loop(struct dentry *dentry)
if (!is_mnt_ns_file(dentry))
return false;
- mnt_ns = get_proc_ns(dentry->d_inode)->ns;
+ mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode));
return current->nsproxy->mnt_ns->seq >= mnt_ns->seq;
}
@@ -2020,7 +2016,10 @@ static int do_loopback(struct path *path, const char *old_name,
if (IS_MNT_UNBINDABLE(old))
goto out2;
- if (!check_mnt(parent) || !check_mnt(old))
+ if (!check_mnt(parent))
+ goto out2;
+
+ if (!check_mnt(old) && old_path.dentry->d_op != &ns_dentry_operations)
goto out2;
if (!recurse && has_locked_children(old, old_path.dentry))
@@ -2640,7 +2639,7 @@ dput_out:
static void free_mnt_ns(struct mnt_namespace *ns)
{
- proc_free_inum(ns->proc_inum);
+ ns_free_inum(&ns->ns);
put_user_ns(ns->user_ns);
kfree(ns);
}
@@ -2662,11 +2661,12 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
if (!new_ns)
return ERR_PTR(-ENOMEM);
- ret = proc_alloc_inum(&new_ns->proc_inum);
+ ret = ns_alloc_inum(&new_ns->ns);
if (ret) {
kfree(new_ns);
return ERR_PTR(ret);
}
+ new_ns->ns.ops = &mntns_operations;
new_ns->seq = atomic64_add_return(1, &mnt_ns_seq);
atomic_set(&new_ns->count, 1);
new_ns->root = NULL;
@@ -3144,31 +3144,31 @@ found:
return visible;
}
-static void *mntns_get(struct task_struct *task)
+static struct ns_common *mntns_get(struct task_struct *task)
{
- struct mnt_namespace *ns = NULL;
+ struct ns_common *ns = NULL;
struct nsproxy *nsproxy;
task_lock(task);
nsproxy = task->nsproxy;
if (nsproxy) {
- ns = nsproxy->mnt_ns;
- get_mnt_ns(ns);
+ ns = &nsproxy->mnt_ns->ns;
+ get_mnt_ns(to_mnt_ns(ns));
}
task_unlock(task);
return ns;
}
-static void mntns_put(void *ns)
+static void mntns_put(struct ns_common *ns)
{
- put_mnt_ns(ns);
+ put_mnt_ns(to_mnt_ns(ns));
}
-static int mntns_install(struct nsproxy *nsproxy, void *ns)
+static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns)
{
struct fs_struct *fs = current->fs;
- struct mnt_namespace *mnt_ns = ns;
+ struct mnt_namespace *mnt_ns = to_mnt_ns(ns);
struct path root;
if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) ||
@@ -3198,17 +3198,10 @@ static int mntns_install(struct nsproxy *nsproxy, void *ns)
return 0;
}
-static unsigned int mntns_inum(void *ns)
-{
- struct mnt_namespace *mnt_ns = ns;
- return mnt_ns->proc_inum;
-}
-
const struct proc_ns_operations mntns_operations = {
.name = "mnt",
.type = CLONE_NEWNS,
.get = mntns_get,
.put = mntns_put,
.install = mntns_install,
- .inum = mntns_inum,
};
diff --git a/fs/nsfs.c b/fs/nsfs.c
new file mode 100644
index 000000000000..af1b24fa899d
--- /dev/null
+++ b/fs/nsfs.c
@@ -0,0 +1,161 @@
+#include <linux/mount.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/proc_ns.h>
+#include <linux/magic.h>
+#include <linux/ktime.h>
+
+static struct vfsmount *nsfs_mnt;
+
+static const struct file_operations ns_file_operations = {
+ .llseek = no_llseek,
+};
+
+static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+ struct inode *inode = dentry->d_inode;
+ const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
+
+ return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
+ ns_ops->name, inode->i_ino);
+}
+
+static void ns_prune_dentry(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ if (inode) {
+ struct ns_common *ns = inode->i_private;
+ atomic_long_set(&ns->stashed, 0);
+ }
+}
+
+const struct dentry_operations ns_dentry_operations =
+{
+ .d_prune = ns_prune_dentry,
+ .d_delete = always_delete_dentry,
+ .d_dname = ns_dname,
+};
+
+static void nsfs_evict(struct inode *inode)
+{
+ struct ns_common *ns = inode->i_private;
+ clear_inode(inode);
+ ns->ops->put(ns);
+}
+
+void *ns_get_path(struct path *path, struct task_struct *task,
+ const struct proc_ns_operations *ns_ops)
+{
+ struct vfsmount *mnt = mntget(nsfs_mnt);
+ struct qstr qname = { .name = "", };
+ struct dentry *dentry;
+ struct inode *inode;
+ struct ns_common *ns;
+ unsigned long d;
+
+again:
+ ns = ns_ops->get(task);
+ if (!ns) {
+ mntput(mnt);
+ return ERR_PTR(-ENOENT);
+ }
+ rcu_read_lock();
+ d = atomic_long_read(&ns->stashed);
+ if (!d)
+ goto slow;
+ dentry = (struct dentry *)d;
+ if (!lockref_get_not_dead(&dentry->d_lockref))
+ goto slow;
+ rcu_read_unlock();
+ ns_ops->put(ns);
+got_it:
+ path->mnt = mnt;
+ path->dentry = dentry;
+ return NULL;
+slow:
+ rcu_read_unlock();
+ inode = new_inode_pseudo(mnt->mnt_sb);
+ if (!inode) {
+ ns_ops->put(ns);
+ mntput(mnt);
+ return ERR_PTR(-ENOMEM);
+ }
+ inode->i_ino = ns->inum;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ inode->i_flags |= S_IMMUTABLE;
+ inode->i_mode = S_IFREG | S_IRUGO;
+ inode->i_fop = &ns_file_operations;
+ inode->i_private = ns;
+
+ dentry = d_alloc_pseudo(mnt->mnt_sb, &qname);
+ if (!dentry) {
+ iput(inode);
+ mntput(mnt);
+ return ERR_PTR(-ENOMEM);
+ }
+ d_instantiate(dentry, inode);
+ dentry->d_fsdata = (void *)ns_ops;
+ d = atomic_long_cmpxchg(&ns->stashed, 0, (unsigned long)dentry);
+ if (d) {
+ d_delete(dentry); /* make sure ->d_prune() does nothing */
+ dput(dentry);
+ cpu_relax();
+ goto again;
+ }
+ goto got_it;
+}
+
+int ns_get_name(char *buf, size_t size, struct task_struct *task,
+ const struct proc_ns_operations *ns_ops)
+{
+ struct ns_common *ns;
+ int res = -ENOENT;
+ ns = ns_ops->get(task);
+ if (ns) {
+ res = snprintf(buf, size, "%s:[%u]", ns_ops->name, ns->inum);
+ ns_ops->put(ns);
+ }
+ return res;
+}
+
+struct file *proc_ns_fget(int fd)
+{
+ struct file *file;
+
+ file = fget(fd);
+ if (!file)
+ return ERR_PTR(-EBADF);
+
+ if (file->f_op != &ns_file_operations)
+ goto out_invalid;
+
+ return file;
+
+out_invalid:
+ fput(file);
+ return ERR_PTR(-EINVAL);
+}
+
+static const struct super_operations nsfs_ops = {
+ .statfs = simple_statfs,
+ .evict_inode = nsfs_evict,
+};
+static struct dentry *nsfs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_pseudo(fs_type, "nsfs:", &nsfs_ops,
+ &ns_dentry_operations, NSFS_MAGIC);
+}
+static struct file_system_type nsfs = {
+ .name = "nsfs",
+ .mount = nsfs_mount,
+ .kill_sb = kill_anon_super,
+};
+
+void __init nsfs_init(void)
+{
+ nsfs_mnt = kern_mount(&nsfs);
+ if (IS_ERR(nsfs_mnt))
+ panic("can't set nsfs up\n");
+ nsfs_mnt->mnt_sb->s_flags &= ~MS_NOUSER;
+}
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 333080d7a671..8420a2f80811 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -32,8 +32,6 @@ static void proc_evict_inode(struct inode *inode)
{
struct proc_dir_entry *de;
struct ctl_table_header *head;
- const struct proc_ns_operations *ns_ops;
- void *ns;
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
@@ -50,11 +48,6 @@ static void proc_evict_inode(struct inode *inode)
RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
sysctl_head_put(head);
}
- /* Release any associated namespace */
- ns_ops = PROC_I(inode)->ns.ns_ops;
- ns = PROC_I(inode)->ns.ns;
- if (ns_ops && ns)
- ns_ops->put(ns);
}
static struct kmem_cache * proc_inode_cachep;
@@ -73,8 +66,7 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
ei->pde = NULL;
ei->sysctl = NULL;
ei->sysctl_entry = NULL;
- ei->ns.ns = NULL;
- ei->ns.ns_ops = NULL;
+ ei->ns_ops = NULL;
inode = &ei->vfs_inode;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
return inode;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index aa7a0ee182e1..d689fd6960d5 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -64,7 +64,7 @@ struct proc_inode {
struct proc_dir_entry *pde;
struct ctl_table_header *sysctl;
struct ctl_table *sysctl_entry;
- struct proc_ns ns;
+ const struct proc_ns_operations *ns_ops;
struct inode vfs_inode;
};
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 89026095f2b5..c9eac4563fa8 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -1,10 +1,6 @@
#include <linux/proc_fs.h>
#include <linux/nsproxy.h>
-#include <linux/sched.h>
#include <linux/ptrace.h>
-#include <linux/fs_struct.h>
-#include <linux/mount.h>
-#include <linux/path.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/utsname.h>
@@ -34,138 +30,45 @@ static const struct proc_ns_operations *ns_entries[] = {
&mntns_operations,
};
-static const struct file_operations ns_file_operations = {
- .llseek = no_llseek,
-};
-
-static const struct inode_operations ns_inode_operations = {
- .setattr = proc_setattr,
-};
-
-static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
-{
- struct inode *inode = dentry->d_inode;
- const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns.ns_ops;
-
- return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
- ns_ops->name, inode->i_ino);
-}
-
-const struct dentry_operations ns_dentry_operations =
-{
- .d_delete = always_delete_dentry,
- .d_dname = ns_dname,
-};
-
-static struct dentry *proc_ns_get_dentry(struct super_block *sb,
- struct task_struct *task, const struct proc_ns_operations *ns_ops)
-{
- struct dentry *dentry, *result;
- struct inode *inode;
- struct proc_inode *ei;
- struct qstr qname = { .name = "", };
- void *ns;
-
- ns = ns_ops->get(task);
- if (!ns)
- return ERR_PTR(-ENOENT);
-
- dentry = d_alloc_pseudo(sb, &qname);
- if (!dentry) {
- ns_ops->put(ns);
- return ERR_PTR(-ENOMEM);
- }
-
- inode = iget_locked(sb, ns_ops->inum(ns));
- if (!inode) {
- dput(dentry);
- ns_ops->put(ns);
- return ERR_PTR(-ENOMEM);
- }
-
- ei = PROC_I(inode);
- if (inode->i_state & I_NEW) {
- inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
- inode->i_op = &ns_inode_operations;
- inode->i_mode = S_IFREG | S_IRUGO;
- inode->i_fop = &ns_file_operations;
- ei->ns.ns_ops = ns_ops;
- ei->ns.ns = ns;
- unlock_new_inode(inode);
- } else {
- ns_ops->put(ns);
- }
-
- d_set_d_op(dentry, &ns_dentry_operations);
- result = d_instantiate_unique(dentry, inode);
- if (result) {
- dput(dentry);
- dentry = result;
- }
-
- return dentry;
-}
-
static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
- struct super_block *sb = inode->i_sb;
- struct proc_inode *ei = PROC_I(inode);
+ const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
struct task_struct *task;
struct path ns_path;
void *error = ERR_PTR(-EACCES);
task = get_proc_task(inode);
if (!task)
- goto out;
+ return error;
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
- goto out_put_task;
-
- ns_path.dentry = proc_ns_get_dentry(sb, task, ei->ns.ns_ops);
- if (IS_ERR(ns_path.dentry)) {
- error = ERR_CAST(ns_path.dentry);
- goto out_put_task;
+ if (ptrace_may_access(task, PTRACE_MODE_READ)) {
+ error = ns_get_path(&ns_path, task, ns_ops);
+ if (!error)
+ nd_jump_link(nd, &ns_path);
}
-
- ns_path.mnt = mntget(nd->path.mnt);
- nd_jump_link(nd, &ns_path);
- error = NULL;
-
-out_put_task:
put_task_struct(task);
-out:
return error;
}
static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
struct inode *inode = dentry->d_inode;
- struct proc_inode *ei = PROC_I(inode);
- const struct proc_ns_operations *ns_ops = ei->ns.ns_ops;
+ const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
struct task_struct *task;
- void *ns;
char name[50];
int res = -EACCES;
task = get_proc_task(inode);
if (!task)
- goto out;
-
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
- goto out_put_task;
+ return res;
- res = -ENOENT;
- ns = ns_ops->get(task);
- if (!ns)
- goto out_put_task;
-
- snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
- res = readlink_copy(buffer, buflen, name);
- ns_ops->put(ns);
-out_put_task:
+ if (ptrace_may_access(task, PTRACE_MODE_READ)) {
+ res = ns_get_name(name, sizeof(name), task, ns_ops);
+ if (res >= 0)
+ res = readlink_copy(buffer, buflen, name);
+ }
put_task_struct(task);
-out:
return res;
}
@@ -189,7 +92,7 @@ static int proc_ns_instantiate(struct inode *dir,
ei = PROC_I(inode);
inode->i_mode = S_IFLNK|S_IRWXUGO;
inode->i_op = &proc_ns_link_inode_operations;
- ei->ns.ns_ops = ns_ops;
+ ei->ns_ops = ns_ops;
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
@@ -267,31 +170,3 @@ const struct inode_operations proc_ns_dir_inode_operations = {
.getattr = pid_getattr,
.setattr = proc_setattr,
};
-
-struct file *proc_ns_fget(int fd)
-{
- struct file *file;
-
- file = fget(fd);
- if (!file)
- return ERR_PTR(-EBADF);
-
- if (file->f_op != &ns_file_operations)
- goto out_invalid;
-
- return file;
-
-out_invalid:
- fput(file);
- return ERR_PTR(-EINVAL);
-}
-
-struct proc_ns *get_proc_ns(struct inode *inode)
-{
- return &PROC_I(inode)->ns;
-}
-
-bool proc_ns_inode(struct inode *inode)
-{
- return inode->i_fop == &ns_file_operations;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-08 12:21:13 +0000