X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=fs%2Fposix_acl.c;h=0ff20797e162790aeadca20fe1a1caca3a495302;hb=aa869750c78648d1ccae1a7e23239e64cc0859c9;hp=10027b42b7e29aefa1b9158ab0ec23de5f00914a;hpb=c125d5e846894043361c0c89c1140be8fd6600b7;p=pandora-kernel.git

diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 10027b42b7e2..0ff20797e162 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -155,6 +155,12 @@ posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p)
 	umode_t mode = 0;
 	int not_equiv = 0;
 
+	/*
+	 * A null ACL can always be presented as mode bits.
+	 */
+	if (!acl)
+		return 0;
+
 	FOREACH_ACL_ENTRY(pa, acl, pe) {
 		switch (pa->e_tag) {
 			case ACL_USER_OBJ:
@@ -218,6 +224,8 @@ posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
 	const struct posix_acl_entry *pa, *pe, *mask_obj;
 	int found = 0;
 
+	want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK;
+
 	FOREACH_ACL_ENTRY(pa, acl, pe) {
                 switch(pa->e_tag) {
                         case ACL_USER_OBJ:
@@ -333,6 +341,36 @@ static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
         return not_equiv;
 }
 
+/**
+ * posix_acl_update_mode  -  update mode in set_acl
+ *
+ * Update the file mode when setting an ACL: compute the new file permission
+ * bits based on the ACL.  In addition, if the ACL is equivalent to the new
+ * file mode, set *acl to NULL to indicate that no ACL should be set.
+ *
+ * As with chmod, clear the setgit bit if the caller is not in the owning group
+ * or capable of CAP_FSETID (see inode_change_ok).
+ *
+ * Called from set_acl inode operations.
+ */
+int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
+			  struct posix_acl **acl)
+{
+	umode_t mode = inode->i_mode;
+	int error;
+
+	error = posix_acl_equiv_mode(*acl, &mode);
+	if (error < 0)
+		return error;
+	if (error == 0)
+		*acl = NULL;
+	if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+		mode &= ~S_ISGID;
+	*mode_p = mode;
+	return 0;
+}
+EXPORT_SYMBOL(posix_acl_update_mode);
+
 /*
  * Modify the ACL for the chmod syscall.
  */