Changeset 363a504 in mainline for uspace/srv/volsrv/empty.c

Timestamp:

2015-11-17T10:49:42Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

f97f5cc2

Parents:

f63a0073

Message:

Fix empty partition detection to work with ISO 9660.

File:

• uspace/srv/volsrv/empty.c (modified) (2 diffs)

uspace/srv/volsrv/empty.c

@@ -43 +43 @@
 #include "empty.h"
 
+/*
+ * The partition will be considered empty if at least a minimum number of
+ * bytes *and* blocks (whichever is larger) at the beginning and end of
+ * the partition is zero.
+ */
+enum {
+        min_empty_bytes = 16384,
+        /*
+         * First block in ISO 9660 that cannot be empty is the first
+         * volume descriptor at LBA 16
+         */
+        min_empty_blocks = 17
+};
+
 static bool mem_is_zero(void *buf, size_t size)
 {
@@ -72 +86 @@
 
         /* Check first 16 kiB / 16 blocks, whichever is more */
-        n = (16384 + block_size - 1) / block_size;
-        if (n < 16)
-                n = 16;
+        n = (min_empty_bytes + block_size - 1) / block_size;
+        if (n < min_empty_blocks)
+                n = min_empty_blocks;
         /*
          * Limit to half of the device so we do not process the same blocks