CRED: Wrap task credential accesses in the XFS filesystem

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: xfs@oss.sgi.com
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/fs/xfs/linux-2.6/xfs_cred.h b/fs/xfs/linux-2.6/xfs_cred.h
index 652721c..293043a 100644
--- a/fs/xfs/linux-2.6/xfs_cred.h
+++ b/fs/xfs/linux-2.6/xfs_cred.h
@@ -24,7 +24,7 @@
  * Credentials
  */
 typedef struct cred {
-	/* EMPTY */
+       /* EMPTY */
 } cred_t;
 
 extern struct cred *sys_cred;
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index d3438c7..67c72ae 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -1007,7 +1007,7 @@
 	 * to the file owner ID, except in cases where the
 	 * CAP_FSETID capability is applicable.
 	 */
-	if (current->fsuid != ip->i_d.di_uid && !capable(CAP_FOWNER)) {
+	if (current_fsuid() != ip->i_d.di_uid && !capable(CAP_FOWNER)) {
 		code = XFS_ERROR(EPERM);
 		goto error_return;
 	}
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index b2f639a..91d6933 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -366,7 +366,7 @@
 		return ENOTDIR;
 	if (vp->i_sb->s_flags & MS_RDONLY)
 		return EROFS;
-	if (XFS_I(vp)->i_d.di_uid != current->fsuid && !capable(CAP_FOWNER))
+	if (XFS_I(vp)->i_d.di_uid != current_fsuid() && !capable(CAP_FOWNER))
 		return EPERM;
 	return 0;
 }
@@ -413,13 +413,13 @@
 		switch (fap->acl_entry[i].ae_tag) {
 		case ACL_USER_OBJ:
 			seen_userobj = 1;
-			if (fuid != current->fsuid)
+			if (fuid != current_fsuid())
 				continue;
 			matched.ae_tag = ACL_USER_OBJ;
 			matched.ae_perm = allows;
 			break;
 		case ACL_USER:
-			if (fap->acl_entry[i].ae_id != current->fsuid)
+			if (fap->acl_entry[i].ae_id != current_fsuid())
 				continue;
 			matched.ae_tag = ACL_USER;
 			matched.ae_perm = allows;