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 --- fs/afs/dir.c | 2 +- fs/afs/dir_silly.c | 6 ++---- 2 files changed, 3 insertions(+), 5 deletions(-) (limited to 'fs/afs') diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 9e7b1fe82c27..bfb69e066672 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -943,7 +943,7 @@ static struct dentry *afs_lookup_atsys(struct inode *dir, struct dentry *dentry) } strcpy(p, name); - ret = lookup_one_len(buf, dentry->d_parent, len); + ret = lookup_noperm(&QSTR(buf), dentry->d_parent); if (IS_ERR(ret) || d_is_positive(ret)) goto out_s; dput(ret); diff --git a/fs/afs/dir_silly.c b/fs/afs/dir_silly.c index a1e581946b93..0b80eb93fa40 100644 --- a/fs/afs/dir_silly.c +++ b/fs/afs/dir_silly.c @@ -113,16 +113,14 @@ int afs_sillyrename(struct afs_vnode *dvnode, struct afs_vnode *vnode, sdentry = NULL; do { - int slen; - dput(sdentry); sillycounter++; /* Create a silly name. Note that the ".__afs" prefix is * understood by the salvager and must not be changed. */ - slen = scnprintf(silly, sizeof(silly), ".__afs%04X", sillycounter); - sdentry = lookup_one_len(silly, dentry->d_parent, slen); + scnprintf(silly, sizeof(silly), ".__afs%04X", sillycounter); + sdentry = lookup_noperm(&QSTR(silly), dentry->d_parent); /* N.B. Better to return EBUSY here ... it could be dangerous * to delete the file while it's in use. -- cgit v1.2.3