[v8,23/41] richacl: Set the owner permissions to the owner mask

Commit Message

Andreas Gruenbacher Sept. 27, 2015, 10:09 p.m. UTC

In the write-through case, change the acl so that owner@ is granted the
permissions set in the owner mask (to match what the permission check
algorithm grants the owner).

Signed-off-by: Andreas Gruenbacher <[e-mail]>
Reviewed-by: J. Bruce Fields <[e-mail]>
---
 fs/richacl_compat.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

Patch

diff --git a/fs/richacl_compat.c b/fs/richacl_compat.c
index 7d007d7..16deeb4 100644
--- a/fs/richacl_compat.c
+++ b/fs/richacl_compat.c
@@ -416,3 +416,49 @@  richacl_propagate_everyone(struct richacl_alloc *alloc)
 	}
 	return 0;
 }
+
+/**
+ * richacl_set_owner_permissions  -  set the owner permissions to the owner mask
+ *
+ * In the write-through case, change the acl so that owner@ is granted the
+ * permissions set in the owner mask (to match what the permission check
+ * algorithm grants the owner).  This leaves at most one efective owner@ allow
+ * entry at the beginning of the acl.
+ */
+static int
+richacl_set_owner_permissions(struct richacl_alloc *alloc)
+{
+	unsigned int x = RICHACE_POSIX_ALWAYS_ALLOWED;
+	unsigned int owner_mask = alloc->acl->a_owner_mask & ~x;
+	unsigned int denied = 0;
+	struct richace *ace;
+
+	if (!((alloc->acl->a_flags & RICHACL_WRITE_THROUGH)))
+		return 0;
+
+	richacl_for_each_entry(ace, alloc->acl) {
+		if (richace_is_owner(ace)) {
+			if (richace_is_allow(ace) && !(owner_mask & denied)) {
+				richace_change_mask(alloc, &ace, owner_mask);
+				owner_mask = 0;
+			} else
+				richace_change_mask(alloc, &ace, 0);
+		} else {
+			if (richace_is_deny(ace))
+				denied |= ace->e_mask;
+		}
+	}
+
+	if (owner_mask & (denied |
+			  ~alloc->acl->a_other_mask |
+			  ~alloc->acl->a_group_mask)) {
+		ace = alloc->acl->a_entries;
+		if (richacl_insert_entry(alloc, &ace))
+			return -1;
+		ace->e_type = RICHACE_ACCESS_ALLOWED_ACE_TYPE;
+		ace->e_flags = RICHACE_SPECIAL_WHO;
+		ace->e_mask = owner_mask;
+		ace->e_id.special = RICHACE_OWNER_SPECIAL_ID;
+	}
+	return 0;
+}