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-rw-r--r--fs/nsfs.c124
1 files changed, 42 insertions, 82 deletions
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 34e1e3e367..07e22a15ef 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -27,26 +27,17 @@ static const struct file_operations ns_file_operations = {
static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
{
struct inode *inode = d_inode(dentry);
- const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
+ struct ns_common *ns = inode->i_private;
+ const struct proc_ns_operations *ns_ops = ns->ops;
return dynamic_dname(buffer, buflen, "%s:[%lu]",
ns_ops->name, inode->i_ino);
}
-static void ns_prune_dentry(struct dentry *dentry)
-{
- struct inode *inode = d_inode(dentry);
- 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,
+const struct dentry_operations ns_dentry_operations = {
.d_delete = always_delete_dentry,
.d_dname = ns_dname,
+ .d_prune = stashed_dentry_prune,
};
static void nsfs_evict(struct inode *inode)
@@ -56,67 +47,16 @@ static void nsfs_evict(struct inode *inode)
ns->ops->put(ns);
}
-static int __ns_get_path(struct path *path, struct ns_common *ns)
-{
- struct vfsmount *mnt = nsfs_mnt;
- struct dentry *dentry;
- struct inode *inode;
- unsigned long d;
-
- 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 = mntget(mnt);
- path->dentry = dentry;
- return 0;
-slow:
- rcu_read_unlock();
- inode = new_inode_pseudo(mnt->mnt_sb);
- if (!inode) {
- ns->ops->put(ns);
- return -ENOMEM;
- }
- inode->i_ino = ns->inum;
- simple_inode_init_ts(inode);
- inode->i_flags |= S_IMMUTABLE;
- inode->i_mode = S_IFREG | S_IRUGO;
- inode->i_fop = &ns_file_operations;
- inode->i_private = ns;
-
- dentry = d_make_root(inode); /* not the normal use, but... */
- if (!dentry)
- return -ENOMEM;
- 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();
- return -EAGAIN;
- }
- goto got_it;
-}
-
int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
void *private_data)
{
- int ret;
+ struct ns_common *ns;
- do {
- struct ns_common *ns = ns_get_cb(private_data);
- if (!ns)
- return -ENOENT;
- ret = __ns_get_path(path, ns);
- } while (ret == -EAGAIN);
+ ns = ns_get_cb(private_data);
+ if (!ns)
+ return -ENOENT;
- return ret;
+ return path_from_stashed(&ns->stashed, nsfs_mnt, ns, path);
}
struct ns_get_path_task_args {
@@ -146,6 +86,7 @@ int open_related_ns(struct ns_common *ns,
struct ns_common *(*get_ns)(struct ns_common *ns))
{
struct path path = {};
+ struct ns_common *relative;
struct file *f;
int err;
int fd;
@@ -154,19 +95,14 @@ int open_related_ns(struct ns_common *ns,
if (fd < 0)
return fd;
- do {
- struct ns_common *relative;
-
- relative = get_ns(ns);
- if (IS_ERR(relative)) {
- put_unused_fd(fd);
- return PTR_ERR(relative);
- }
-
- err = __ns_get_path(&path, relative);
- } while (err == -EAGAIN);
+ relative = get_ns(ns);
+ if (IS_ERR(relative)) {
+ put_unused_fd(fd);
+ return PTR_ERR(relative);
+ }
- if (err) {
+ err = path_from_stashed(&relative->stashed, nsfs_mnt, relative, &path);
+ if (err < 0) {
put_unused_fd(fd);
return err;
}
@@ -249,7 +185,8 @@ bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino)
static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
- const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
+ const struct ns_common *ns = inode->i_private;
+ const struct proc_ns_operations *ns_ops = ns->ops;
seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino);
return 0;
@@ -261,6 +198,28 @@ static const struct super_operations nsfs_ops = {
.show_path = nsfs_show_path,
};
+static int nsfs_init_inode(struct inode *inode, void *data)
+{
+ struct ns_common *ns = data;
+
+ inode->i_private = data;
+ inode->i_mode |= S_IRUGO;
+ inode->i_fop = &ns_file_operations;
+ inode->i_ino = ns->inum;
+ return 0;
+}
+
+static void nsfs_put_data(void *data)
+{
+ struct ns_common *ns = data;
+ ns->ops->put(ns);
+}
+
+static const struct stashed_operations nsfs_stashed_ops = {
+ .init_inode = nsfs_init_inode,
+ .put_data = nsfs_put_data,
+};
+
static int nsfs_init_fs_context(struct fs_context *fc)
{
struct pseudo_fs_context *ctx = init_pseudo(fc, NSFS_MAGIC);
@@ -268,6 +227,7 @@ static int nsfs_init_fs_context(struct fs_context *fc)
return -ENOMEM;
ctx->ops = &nsfs_ops;
ctx->dops = &ns_dentry_operations;
+ fc->s_fs_info = (void *)&nsfs_stashed_ops;
return 0;
}