fs: take the ACL checks to common code

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 13 insertions, 11 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 120efc76d3d0..ec2e5656b444 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -196,20 +196,22 @@ static int check_acl(struct inode *inode, int mask)
         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 ->check_acl call.
+         * 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 check_acl() function
-         * at all, we'll just create the negative cache entry.
+         * 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->check_acl)
-                        return inode->i_op->check_acl(inode, mask);
-
-                set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
-                return -EAGAIN;
+                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;
+                }
         }
 
         if (acl) {