Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin

* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...

1 files changed, 13 insertions, 7 deletions

diff --git a/fs/generic_acl.c b/fs/generic_acl.c
index 6bc9e3a5a693..06c48a891832 100644
--- a/fs/generic_acl.c
+++ b/fs/generic_acl.c
@@ -190,14 +190,20 @@ generic_acl_chmod(struct inode *inode)
 }
 
 int
-generic_check_acl(struct inode *inode, int mask)
+generic_check_acl(struct inode *inode, int mask, unsigned int flags)
 {
-        struct posix_acl *acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
-
-        if (acl) {
-                int error = posix_acl_permission(inode, acl, mask);
-                posix_acl_release(acl);
-                return error;
+        if (flags & IPERM_FLAG_RCU) {
+                if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
+                        return -ECHILD;
+        } else {
+                struct posix_acl *acl;
+
+                acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
+                if (acl) {
+                        int error = posix_acl_permission(inode, acl, mask);
+                        posix_acl_release(acl);
+                        return error;
+                }
         }
         return -EAGAIN;
 }