fs: dedup handling of struct filename init and refcounts bumps

Commit Message

Mateusz Guzik March 13, 2025, 2:27 p.m. UTC

No functional changes.

Signed-off-by: Mateusz Guzik <[e-mail]>
---

This is extracted from the patch which tried to introduce optional
non-atomic operation.

I think this is an ok cleanup, but I'm not going to argue about it.

ultimately this is a big NOP

 fs/namei.c         | 17 +++++++++--------
 include/linux/fs.h |  6 ++++++
 kernel/auditsc.c   | 12 +++++-------
 3 files changed, 20 insertions(+), 15 deletions(-)

Comments

Christian Brauner March 14, 2025, 3:44 p.m. UTC | #1

On Thu, 13 Mar 2025 15:27:44 +0100, Mateusz Guzik wrote:
> No functional changes.
> 
> 

Applied to the vfs-6.15.misc branch of the vfs/vfs.git tree.
Patches in the vfs-6.15.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.15.misc

[1/1] fs: dedup handling of struct filename init and refcounts bumps
      https://git.kernel.org/vfs/vfs/c/e05a35026336

Patch

diff --git a/fs/namei.c b/fs/namei.c
index 06765d320e7e..699158c325bf 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -125,6 +125,13 @@ 
 
 #define EMBEDDED_NAME_MAX	(PATH_MAX - offsetof(struct filename, iname))
 
+static inline void initname(struct filename *name)
+{
+	name->uptr = NULL;
+	name->aname = NULL;
+	atomic_set(&name->refcnt, 1);
+}
+
 struct filename *
 getname_flags(const char __user *filename, int flags)
 {
@@ -203,10 +210,7 @@  getname_flags(const char __user *filename, int flags)
 			return ERR_PTR(-ENAMETOOLONG);
 		}
 	}
-
-	atomic_set(&result->refcnt, 1);
-	result->uptr = filename;
-	result->aname = NULL;
+	initname(result);
 	audit_getname(result);
 	return result;
 }
@@ -264,11 +268,8 @@  struct filename *getname_kernel(const char * filename)
 		return ERR_PTR(-ENAMETOOLONG);
 	}
 	memcpy((char *)result->name, filename, len);
-	result->uptr = NULL;
-	result->aname = NULL;
-	atomic_set(&result->refcnt, 1);
+	initname(result);
 	audit_getname(result);
-
 	return result;
 }
 EXPORT_SYMBOL(getname_kernel);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 62440a9383dc..016b0fe1536e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2865,6 +2865,12 @@  static inline struct filename *getname_maybe_null(const char __user *name, int f
 extern void putname(struct filename *name);
 DEFINE_FREE(putname, struct filename *, if (!IS_ERR_OR_NULL(_T)) putname(_T))
 
+static inline struct filename *refname(struct filename *name)
+{
+	atomic_inc(&name->refcnt);
+	return name;
+}
+
 extern int finish_open(struct file *file, struct dentry *dentry,
 			int (*open)(struct inode *, struct file *));
 extern int finish_no_open(struct file *file, struct dentry *dentry);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 9c853cde9abe..78fd876a5473 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2207,10 +2207,8 @@  __audit_reusename(const __user char *uptr)
 	list_for_each_entry(n, &context->names_list, list) {
 		if (!n->name)
 			continue;
-		if (n->name->uptr == uptr) {
-			atomic_inc(&n->name->refcnt);
-			return n->name;
-		}
+		if (n->name->uptr == uptr)
+			return refname(n->name);
 	}
 	return NULL;
 }
@@ -2237,7 +2235,7 @@  void __audit_getname(struct filename *name)
 	n->name = name;
 	n->name_len = AUDIT_NAME_FULL;
 	name->aname = n;
-	atomic_inc(&name->refcnt);
+	refname(name);
 }
 
 static inline int audit_copy_fcaps(struct audit_names *name,
@@ -2369,7 +2367,7 @@  void __audit_inode(struct filename *name, const struct dentry *dentry,
 		return;
 	if (name) {
 		n->name = name;
-		atomic_inc(&name->refcnt);
+		refname(name);
 	}
 
 out:
@@ -2496,7 +2494,7 @@  void __audit_inode_child(struct inode *parent,
 		if (found_parent) {
 			found_child->name = found_parent->name;
 			found_child->name_len = AUDIT_NAME_FULL;
-			atomic_inc(&found_child->name->refcnt);
+			refname(found_child->name);
 		}
 	}