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authorChristian Brauner <brauner@kernel.org>2024-02-18 14:51:23 +0100
committerChristian Brauner <brauner@kernel.org>2024-03-01 12:23:44 +0100
commit1fa08aece42512be072351f482096d5796edf7ca (patch)
tree6ebfa283e0423520423e886bdf0e06c8252d6ec4 /fs/nsfs.c
parentlibfs: add path_from_stashed() (diff)
downloadlinux-1fa08aece42512be072351f482096d5796edf7ca.tar.xz
linux-1fa08aece42512be072351f482096d5796edf7ca.zip
nsfs: convert to path_from_stashed() helper
Use the newly added path_from_stashed() helper for nsfs. Link: https://lore.kernel.org/r/20240218-neufahrzeuge-brauhaus-fb0eb6459771@brauner Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/nsfs.c')
-rw-r--r--fs/nsfs.c73
1 files changed, 18 insertions, 55 deletions
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 34e1e3e36733..39dc2604bec0 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -27,7 +27,8 @@ 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);
@@ -38,7 +39,7 @@ 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);
+ WRITE_ONCE(ns->stashed, NULL);
}
}
@@ -56,54 +57,6 @@ 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)
{
@@ -113,10 +66,16 @@ int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
struct ns_common *ns = ns_get_cb(private_data);
if (!ns)
return -ENOENT;
- ret = __ns_get_path(path, ns);
+ ret = path_from_stashed(&ns->stashed, ns->inum, nsfs_mnt,
+ &ns_file_operations, ns, path);
+ if (ret <= 0 && ret != -EAGAIN)
+ ns->ops->put(ns);
} while (ret == -EAGAIN);
- return ret;
+ if (ret < 0)
+ return ret;
+
+ return 0;
}
struct ns_get_path_task_args {
@@ -163,10 +122,13 @@ int open_related_ns(struct ns_common *ns,
return PTR_ERR(relative);
}
- err = __ns_get_path(&path, relative);
+ err = path_from_stashed(&relative->stashed, relative->inum, nsfs_mnt,
+ &ns_file_operations, relative, &path);
+ if (err <= 0 && err != -EAGAIN)
+ relative->ops->put(relative);
} while (err == -EAGAIN);
- if (err) {
+ if (err < 0) {
put_unused_fd(fd);
return err;
}
@@ -249,7 +211,8 @@ 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;