fs: add get_acl helper

Factor out the code to get an ACL either from the inode or disk from
check_acl, so that it can be used elsewhere later on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 3531deebad3084104e6a9fca7116ba68890ad5af..bcb838e2e52f24593da609abba67dc5ab5336947 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -235,27 +235,9 @@ static int check_acl(struct inode *inode, int mask)
                return posix_acl_permission(inode, acl, mask & ~MAY_NOT_BLOCK);
        }
 
-       acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
-
-       /*
-        * A filesystem can force a ACL callback by just never filling the
-        * ACL cache. But normally you'd fill the cache either at inode
-        * instantiation time, or on the first ->get_acl call.
-        *
-        * If the filesystem doesn't have a get_acl() function at all, we'll
-        * just create the negative cache entry.
-        */
-       if (acl == ACL_NOT_CACHED) {
-               if (inode->i_op->get_acl) {
-                       acl = inode->i_op->get_acl(inode, ACL_TYPE_ACCESS);
-                       if (IS_ERR(acl))
-                               return PTR_ERR(acl);
-               } else {
-                       set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
-                       return -EAGAIN;
-               }
-       }
-
+       acl = get_acl(inode, ACL_TYPE_ACCESS);
+       if (IS_ERR(acl))
+               return PTR_ERR(acl);
        if (acl) {
                int error = posix_acl_permission(inode, acl, mask);
                posix_acl_release(acl);

diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 359d70b0e947d332ffd716479ac36f406ba39749..30524de49a6bc47c7c47e6f1f58ccddb1432d6b9 100644 (file)
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -26,6 +26,33 @@ EXPORT_SYMBOL(posix_acl_valid);
 EXPORT_SYMBOL(posix_acl_equiv_mode);
 EXPORT_SYMBOL(posix_acl_from_mode);
 
+struct posix_acl *get_acl(struct inode *inode, int type)
+{
+       struct posix_acl *acl;
+
+       acl = get_cached_acl(inode, type);
+       if (acl != ACL_NOT_CACHED)
+               return acl;
+
+       if (!IS_POSIXACL(inode))
+               return NULL;
+
+       /*
+        * A filesystem can force a ACL callback by just never filling the
+        * ACL cache. But normally you'd fill the cache either at inode
+        * instantiation time, or on the first ->get_acl call.
+        *
+        * If the filesystem doesn't have a get_acl() function at all, we'll
+        * just create the negative cache entry.
+        */
+       if (!inode->i_op->get_acl) {
+               set_cached_acl(inode, type, NULL);
+               return NULL;
+       }
+       return inode->i_op->get_acl(inode, type);
+}
+EXPORT_SYMBOL(get_acl);
+
 /*
  * Init a fresh posix_acl
  */

diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h
index 7931efe7117553d00a920cfd4aef757f72578658..a8d9918c0b20f2ffb2e9dddd4ce3a2b8a495736d 100644 (file)
--- a/include/linux/posix_acl.h
+++ b/include/linux/posix_acl.h
@@ -175,4 +175,6 @@ static inline void cache_no_acl(struct inode *inode)
 #endif
 }
 
+struct posix_acl *get_acl(struct inode *inode, int type);
+
 #endif  /* __LINUX_POSIX_ACL_H */