get rid of boilerplate switches in posix_acl.h

the only potentially subtle thing here: get_cached_acl()
is never called with the second argument other than
ACL_TYPE_{ACCESS,DEFAULT}.  IOW, that return ERR_PTR(-EINVAL)
in there might as well be BUG().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h
index 951bba8..a9c2fb2 100644 (file)
--- a/include/linux/posix_acl.h
+++ b/include/linux/posix_acl.h
@@ -84,20 +84,22 @@ extern struct posix_acl *get_posix_acl(struct inode *, int);
 extern int set_posix_acl(struct inode *, int, struct posix_acl *);
 
 #ifdef CONFIG_FS_POSIX_ACL
-static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
+static inline struct posix_acl **acl_by_type(struct inode *inode, int type)
 {
-       struct posix_acl **p, *acl;
        switch (type) {
        case ACL_TYPE_ACCESS:
-               p = &inode->i_acl;
-               break;
+               return &inode->i_acl;
        case ACL_TYPE_DEFAULT:
-               p = &inode->i_default_acl;
-               break;
+               return &inode->i_default_acl;
        default:
-               return ERR_PTR(-EINVAL);
+               BUG();
        }
-       acl = ACCESS_ONCE(*p);
+}
+
+static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
+{
+       struct posix_acl **p = acl_by_type(inode, type);
+       struct posix_acl *acl = ACCESS_ONCE(*p);
        if (acl) {
                spin_lock(&inode->i_lock);
                acl = *p;
@@ -110,18 +112,8 @@ static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
 
 static inline int negative_cached_acl(struct inode *inode, int type)
 {
-       struct posix_acl **p, *acl;
-       switch (type) {
-       case ACL_TYPE_ACCESS:
-               p = &inode->i_acl;
-               break;
-       case ACL_TYPE_DEFAULT:
-               p = &inode->i_default_acl;
-               break;
-       default:
-               BUG();
-       }
-       acl = ACCESS_ONCE(*p);
+       struct posix_acl **p = acl_by_type(inode, type);
+       struct posix_acl *acl = ACCESS_ONCE(*p);
        if (acl)
                return 0;
        return 1;
@@ -131,18 +123,11 @@ static inline void set_cached_acl(struct inode *inode,
                                  int type,
                                  struct posix_acl *acl)
 {
-       struct posix_acl *old = NULL;
+       struct posix_acl **p = acl_by_type(inode, type);
+       struct posix_acl *old;
        spin_lock(&inode->i_lock);
-       switch (type) {
-       case ACL_TYPE_ACCESS:
-               old = inode->i_acl;
-               inode->i_acl = posix_acl_dup(acl);
-               break;
-       case ACL_TYPE_DEFAULT:
-               old = inode->i_default_acl;
-               inode->i_default_acl = posix_acl_dup(acl);
-               break;
-       }
+       old = *p;
+       *p = posix_dup_acl(acl);
        spin_unlock(&inode->i_lock);
        if (old != ACL_NOT_CACHED)
                posix_acl_release(old);
@@ -150,18 +135,11 @@ static inline void set_cached_acl(struct inode *inode,
 
 static inline void forget_cached_acl(struct inode *inode, int type)
 {
-       struct posix_acl *old = NULL;
+       struct posix_acl **p = acl_by_type(inode, type);
+       struct posix_acl *old;
        spin_lock(&inode->i_lock);
-       switch (type) {
-       case ACL_TYPE_ACCESS:
-               old = inode->i_acl;
-               inode->i_acl = ACL_NOT_CACHED;
-               break;
-       case ACL_TYPE_DEFAULT:
-               old = inode->i_default_acl;
-               inode->i_default_acl = ACL_NOT_CACHED;
-               break;
-       }
+       old = *p;
+       *p = ACL_NOT_CACHED;
        spin_unlock(&inode->i_lock);
        if (old != ACL_NOT_CACHED)
                posix_acl_release(old);