ext4: cache NULL when both default_acl and acl are NULL

Chengguang Xu · tytso · commit 6fd941784b8a · 2018-10-06T22:40:34.000-04:00
default_acl and acl of newly created inode will be initiated as
ACL_NOT_CACHED in vfs function inode_init_always() and later will be
updated by calling xxx_init_acl() in specific filesystems.  However,
when default_acl and acl are NULL then they keep the value of
ACL_NOT_CACHED.  This patch changes the code to cache NULL for acl /
default_acl in this case to save unnecessary ACL lookup attempt.

Signed-off-by: Chengguang Xu &lt;cgxu519@gmx.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
@@ -284,12 +284,16 @@ ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 		error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
 				       default_acl, XATTR_CREATE);
 		posix_acl_release(default_acl);
+	} else {
+		inode->i_default_acl = NULL;
 	}
 	if (acl) {
 		if (!error)
 			error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
 					       acl, XATTR_CREATE);
 		posix_acl_release(acl);
+	} else {
+		inode->i_acl = NULL;
 	}
 	return error;
 }

Original file line number	Diff line number	Diff line change
`@@ -284,12 +284,16 @@ ext4_init_acl(handle_t handle, struct inode inode, struct inode *dir)`
`284`	`284`	`error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,`
`285`	`285`	`default_acl, XATTR_CREATE);`
`286`	`286`	`posix_acl_release(default_acl);`
	`287`	`+ } else {`
	`288`	`+ inode->i_default_acl = NULL;`
`287`	`289`	`}`
`288`	`290`	`if (acl) {`
`289`	`291`	`if (!error)`
`290`	`292`	`error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,`
`291`	`293`	`acl, XATTR_CREATE);`
`292`	`294`	`posix_acl_release(acl);`
	`295`	`+ } else {`
	`296`	`+ inode->i_acl = NULL;`
`293`	`297`	`}`
`294`	`298`	`return error;`
`295`	`299`	`}`