From fa6fe07d1536361a227d655e69ca270faf28fdbe Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 19 Mar 2025 14:01:35 +1100 Subject: VFS: rename lookup_one_len family to lookup_noperm and remove permission check The lookup_one_len family of functions is (now) only used internally by a filesystem on itself either - in a context where permission checking is irrelevant such as by a virtual filesystem populating itself, or xfs accessing its ORPHANAGE or dquota accessing the quota file; or - in a context where a permission check (MAY_EXEC on the parent) has just been performed such as a network filesystem finding in "silly-rename" file in the same directory. This is also the context after the _parentat() functions where currently lookup_one_qstr_excl() is used. So the permission check is pointless. The name "one_len" is unhelpful in understanding the purpose of these functions and should be changed. Most of the callers pass the len as "strlen()" so using a qstr and QSTR() can simplify the code. This patch renames these functions (include lookup_positive_unlocked() which is part of the family despite the name) to have a name based on "lookup_noperm". They are changed to receive a 'struct qstr' instead of separate name and len. In a few cases the use of QSTR() results in a new call to strlen(). try_lookup_noperm() takes a pointer to a qstr instead of the whole qstr. This is consistent with d_hash_and_lookup() (which is nearly identical) and useful for lookup_noperm_unlocked(). The new lookup_noperm_common() doesn't take a qstr yet. That will be tidied up in a subsequent patch. Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250319031545.2999807-5-neil@brown.name Signed-off-by: Christian Brauner --- drivers/android/binderfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/android') diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c index 94c6446604fc..98da8c4eea59 100644 --- a/drivers/android/binderfs.c +++ b/drivers/android/binderfs.c @@ -187,7 +187,7 @@ static int binderfs_binder_device_create(struct inode *ref_inode, inode_lock(d_inode(root)); /* look it up */ - dentry = lookup_one_len(name, root, name_len); + dentry = lookup_noperm(&QSTR(name), root); if (IS_ERR(dentry)) { inode_unlock(d_inode(root)); ret = PTR_ERR(dentry); @@ -487,7 +487,7 @@ static struct dentry *binderfs_create_dentry(struct dentry *parent, { struct dentry *dentry; - dentry = lookup_one_len(name, parent, strlen(name)); + dentry = lookup_noperm(&QSTR(name), parent); if (IS_ERR(dentry)) return dentry; -- cgit v1.2.3