[PATCH v4 3/6] namespace: extract show_path() helper

From: Miklos Szeredi
Date: Wed Oct 25 2023 - 10:39:52 EST


To be used by the statmount(2) syscall as well.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/internal.h | 2 ++
fs/namespace.c | 9 +++++++++
fs/proc_namespace.c | 10 +++-------
3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index d64ae03998cc..0c4f4cf2ff5a 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -83,6 +83,8 @@ int path_mount(const char *dev_name, struct path *path,
const char *type_page, unsigned long flags, void *data_page);
int path_umount(struct path *path, int flags);

+int show_path(struct seq_file *m, struct dentry *root);
+
/*
* fs_struct.c
*/
diff --git a/fs/namespace.c b/fs/namespace.c
index 0eab47ffc76c..7a33ea391a02 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -4672,6 +4672,15 @@ SYSCALL_DEFINE5(mount_setattr, int, dfd, const char __user *, path,
return err;
}

+int show_path(struct seq_file *m, struct dentry *root)
+{
+ if (root->d_sb->s_op->show_path)
+ return root->d_sb->s_op->show_path(m, root);
+
+ seq_dentry(m, root, " \t\n\\");
+ return 0;
+}
+
static void __init init_mount_tree(void)
{
struct vfsmount *mnt;
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 73d2274d5f59..0a808951b7d3 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -142,13 +142,9 @@ static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)

seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
MAJOR(sb->s_dev), MINOR(sb->s_dev));
- if (sb->s_op->show_path) {
- err = sb->s_op->show_path(m, mnt->mnt_root);
- if (err)
- goto out;
- } else {
- seq_dentry(m, mnt->mnt_root, " \t\n\\");
- }
+ err = show_path(m, mnt->mnt_root);
+ if (err)
+ goto out;
seq_putc(m, ' ');

/* mountpoints outside of chroot jail will give SEQ_SKIP on this */
--
2.41.0