[PATCH 01/13] fs/proc: Don't lock root inode when creating "self" and "thread-self"

NeilBrown
2026-02-04T05:08:15Z

From: NeilBrown <neil@brown.name>

proc_setup_self() and proc_setup_thread_self() are only called from
proc_fill_super() which is before the filesystem is "live". So there is
no need to lock the root directory when adding "self" and "thread-self".
This is clear from simple_fill_super() which provides similar
functionality for other filesystems and does not lock anything.

The locking is not harmful, except that it may be confusing to a reader.
As part of a an effort to centralise all locking for directories for
name-based operations (prior to changing some locking rules), it is
simplest to remove the locking here.

Signed-off-by: NeilBrown <neil@brown.name>
---
fs/proc/self.c | 3 ---
fs/proc/thread_self.c | 3 ---
2 files changed, 6 deletions(-)

diff --git a/fs/proc/self.c b/fs/proc/self.c
index 62d2c0cfe35c..56adf1c68f7a 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -35,11 +35,9 @@ unsigned self_inum __ro_after_init;

int proc_setup_self(struct super_block *s)
{
- struct inode *root_inode = d_inode(s->s_root);
struct dentry *self;
int ret = -ENOMEM;

- inode_lock(root_inode);
self = d_alloc_name(s->s_root, "self");
if (self) {
struct inode *inode = new_inode(s);
@@ -55,7 +53,6 @@ int proc_setup_self(struct super_block *s)
}
dput(self);
}
- inode_unlock(root_inode);

if (ret)
pr_err("proc_fill_super: can't allocate /proc/self\n");
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index d6113dbe58e0..61ac62c3fd9f 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -35,11 +35,9 @@ unsigned thread_self_inum __ro_after_init;

int proc_setup_thread_self(struct super_block *s)
{
- struct inode *root_inode = d_inode(s->s_root);
struct dentry *thread_self;
int ret = -ENOMEM;

- inode_lock(root_inode);
thread_self = d_alloc_name(s->s_root, "thread-self");
if (thread_self) {
struct inode *inode = new_inode(s);
@@ -55,7 +53,6 @@ int proc_setup_thread_self(struct super_block *s)
}
dput(thread_self);
}
- inode_unlock(root_inode);

if (ret)
pr_err("proc_fill_super: can't allocate /proc/thread-self\n");
--
2.50.0.107.gf914562f5916.dirty