[-V5,15/24] richacl: Update the file masks in chmod()
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Message ID 1298469131-16555-16-git-send-email-aneesh.kumar@linux.vnet.ibm.com
State New, archived
Headers show

Commit Message

Aneesh Kumar K.V Feb. 23, 2011, 1:52 p.m. UTC
None

Patch
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diff --git a/fs/richacl_base.c b/fs/richacl_base.c
index 69ddb00..b59c75c 100644
--- a/fs/richacl_base.c
+++ b/fs/richacl_base.c
@@ -353,3 +353,43 @@  restart:
 	acl->a_flags &= ~ACL4_MASKED;
 }
 EXPORT_SYMBOL_GPL(richacl_compute_max_masks);
+
+/**
+ * richacl_chmod  -  update the file masks to reflect the new mode
+ * @mode:	new file permission bits
+ *
+ * Return a copy of @acl where the file masks have been replaced by the file
+ * masks corresponding to the file permission bits in @mode, or returns @acl
+ * itself if the file masks are already up to date.  Takes over a reference
+ * to @acl.
+ */
+struct richacl *
+richacl_chmod(struct richacl *acl, mode_t mode)
+{
+	unsigned int owner_mask, group_mask, other_mask;
+	struct richacl *clone;
+
+	owner_mask = richacl_mode_to_mask(mode >> 6) |
+		     ACE4_POSIX_OWNER_ALLOWED;
+	group_mask = richacl_mode_to_mask(mode >> 3);
+	other_mask = richacl_mode_to_mask(mode);
+
+	if (acl->a_owner_mask == owner_mask &&
+	    acl->a_group_mask == group_mask &&
+	    acl->a_other_mask == other_mask &&
+	    (acl->a_flags & ACL4_MASKED))
+		return acl;
+
+	clone = richacl_clone(acl);
+	richacl_put(acl);
+	if (!clone)
+		return ERR_PTR(-ENOMEM);
+
+	clone->a_flags |= ACL4_MASKED;
+	clone->a_owner_mask = owner_mask;
+	clone->a_group_mask = group_mask;
+	clone->a_other_mask = other_mask;
+
+	return clone;
+}
+EXPORT_SYMBOL_GPL(richacl_chmod);
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index f491e59..3aa165b 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -288,5 +288,6 @@  extern int richacl_masks_to_mode(const struct richacl *);
 extern unsigned int richacl_mode_to_mask(mode_t);
 extern unsigned int richacl_want_to_mask(int);
 extern void richacl_compute_max_masks(struct richacl *);
+extern struct richacl *richacl_chmod(struct richacl *, mode_t);
 
 #endif /* __RICHACL_H */