Merge patch series "Minor cleanup preparation for some dir-locking API changes"

NeilBrown <neil@brown.name> says:

The following 4 patches provide further cleanup that serves as
preparation for some dir-locking API changes that I want to make.

* patches from https://lore.kernel.org/20250608230952.20539-1-neil@brown.name:
  exportfs: use lookup_one_unlocked()
  coda: use iterate_dir() in coda_readdir()
  VFS: Minor fixes for porting.rst
  VFS: merge lookup_one_qstr_excl_raw() back into lookup_one_qstr_excl()

Link: https://lore.kernel.org/20250608230952.20539-1-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

Documentation/filesystems/porting.rst

@@ -1224,9 +1224,6 @@ lookup_noperm_unlocked(), lookup_noperm_positive_unlocked().  They now
 take a qstr instead of separate name and length.  QSTR() can be used
 when strlen() is needed for the length.
 
-For try_lookup_noperm() a reference to the qstr is passed in case the
-hash might subsequently be needed.
-
 These function no longer do any permission checking - they previously
 checked that the caller has 'X' permission on the parent.  They must
 ONLY be used internally by a filesystem on itself when it knows that

fs/coda/dir.c

@@ -429,17 +429,9 @@ static int coda_readdir(struct file *coda_file, struct dir_context *ctx)
 	cfi = coda_ftoc(coda_file);
 	host_file = cfi->cfi_container;
 
-	if (host_file->f_op->iterate_shared) {
-		struct inode *host_inode = file_inode(host_file);
-		ret = -ENOENT;
-		if (!IS_DEADDIR(host_inode)) {
-			inode_lock_shared(host_inode);
-			ret = host_file->f_op->iterate_shared(host_file, ctx);
-			file_accessed(host_file);
-			inode_unlock_shared(host_inode);
-		}
+	ret = iterate_dir(host_file, ctx);
+	if (ret != -ENOTDIR)
 		return ret;
-	}
 	/* Venus: we must read Venus dirents from a file */
 	return coda_venus_readdir(coda_file, ctx);
 }

fs/exportfs/expfs.c

@@ -549,15 +549,13 @@ exportfs_decode_fh_raw(struct vfsmount *mnt, struct fid *fid, int fh_len,
 			goto err_result;
 		}
 
-		inode_lock(target_dir->d_inode);
-		nresult = lookup_one(mnt_idmap(mnt), &QSTR(nbuf), target_dir);
+		nresult = lookup_one_unlocked(mnt_idmap(mnt), &QSTR(nbuf), target_dir);
 		if (!IS_ERR(nresult)) {
 			if (unlikely(nresult->d_inode != result->d_inode)) {
 				dput(nresult);
 				nresult = ERR_PTR(-ESTALE);
 			}
 		}
-		inode_unlock(target_dir->d_inode);
 		/*
 		 * At this point we are done with the parent, but it's pinned
 		 * by the child dentry anyway.

fs/namei.c

@@ -1665,17 +1665,25 @@ static struct dentry *lookup_dcache(const struct qstr *name,
 	return dentry;
 }
 
-static struct dentry *lookup_one_qstr_excl_raw(const struct qstr *name,
-					       struct dentry *base,
-					       unsigned int flags)
+/*
+ * Parent directory has inode locked exclusive.  This is one
+ * and only case when ->lookup() gets called on non in-lookup
+ * dentries - as the matter of fact, this only gets called
+ * when directory is guaranteed to have no in-lookup children
+ * at all.
+ * Will return -ENOENT if name isn't found and LOOKUP_CREATE wasn't passed.
+ * Will return -EEXIST if name is found and LOOKUP_EXCL was passed.
+ */
+struct dentry *lookup_one_qstr_excl(const struct qstr *name,
+				    struct dentry *base, unsigned int flags)
 {
 	struct dentry *dentry;
 	struct dentry *old;
 	struct inode *dir;
 
 	dentry = lookup_dcache(name, base, flags);
 	if (dentry)
-		return dentry;
+		goto found;
 
 	/* Don't create child dentry for a dead directory. */
 	dir = base->d_inode;
@@ -1691,24 +1699,7 @@ static struct dentry *lookup_one_qstr_excl_raw(const struct qstr *name,
 		dput(dentry);
 		dentry = old;
 	}
-	return dentry;
-}
-
-/*
- * Parent directory has inode locked exclusive.  This is one
- * and only case when ->lookup() gets called on non in-lookup
- * dentries - as the matter of fact, this only gets called
- * when directory is guaranteed to have no in-lookup children
- * at all.
- * Will return -ENOENT if name isn't found and LOOKUP_CREATE wasn't passed.
- * Will return -EEXIST if name is found and LOOKUP_EXCL was passed.
- */
-struct dentry *lookup_one_qstr_excl(const struct qstr *name,
-				    struct dentry *base, unsigned int flags)
-{
-	struct dentry *dentry;
-
-	dentry = lookup_one_qstr_excl_raw(name, base, flags);
+found:
 	if (IS_ERR(dentry))
 		return dentry;
 	if (d_is_negative(dentry) && !(flags & LOOKUP_CREATE)) {
@@ -2790,7 +2781,7 @@ struct dentry *kern_path_locked_negative(const char *name, struct path *path)
 	if (unlikely(type != LAST_NORM))
 		return ERR_PTR(-EINVAL);
 	inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT);
-	d = lookup_one_qstr_excl_raw(&last, parent_path.dentry, 0);
+	d = lookup_one_qstr_excl(&last, parent_path.dentry, LOOKUP_CREATE);
 	if (IS_ERR(d)) {
 		inode_unlock(parent_path.dentry->d_inode);
 		return d;