Changeset df3caec5 in mainline

Timestamp:

2011-10-14T20:01:24Z (13 years ago)

Author:

Maurizio Lombardi <m.lombardi85@…>

Branches:

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

Children:

3958e315, 4c3ad56

Parents:

2ac7af3

Message:

Add basic MINIX filesystem sanity check

File:

• uspace/srv/fs/mfs/mfs_ops.c (modified) (4 diffs)

uspace/srv/fs/mfs/mfs_ops.c

@@ -69 +69 @@
 static int mfs_instance_get(service_id_t service_id,
     struct mfs_instance **instance);
-
+static int mfs_check_sanity(struct mfs_sb_info *sbi);
+static bool is_power_of_two(uint32_t n);
 
 static hash_table_t open_nodes;
@@ -261 +262 @@
 
         sbi->itable_off = 2 + sbi->ibmap_blocks + sbi->zbmap_blocks;
+        if ((rc = mfs_check_sanity(sbi)) != EOK) {
+                fprintf(stderr, "Filesystem corrupted, invalid superblock");
+                goto out_error;
+        }
 
         rc = block_cache_init(service_id, sbi->block_size, 0, cmode);
@@ -1071 +1076 @@
 }
 
+/** Filesystem sanity check
+ *
+ * @param Pointer to the MFS superblock.
+ *
+ * @return EOK on success, ENOTSUP otherwise.
+ */
+static int
+mfs_check_sanity(struct mfs_sb_info *sbi)
+{
+        if (!is_power_of_two(sbi->block_size) ||
+            sbi->block_size < MFS_MIN_BLOCKSIZE ||
+            sbi->block_size > MFS_MAX_BLOCKSIZE)
+                return ENOTSUP;
+        else if (sbi->ibmap_blocks == 0 || sbi->zbmap_blocks == 0)
+                return ENOTSUP;
+        else if (sbi->ninodes == 0 || sbi->nzones == 0)
+                return ENOTSUP;
+        else if (sbi->firstdatazone == 0)
+                return ENOTSUP;
+
+        return EOK;
+}
+
 static int
 mfs_close(service_id_t service_id, fs_index_t index)
@@ -1091 +1119 @@
 
         return mfs_node_put(fn);
+}
+
+/** Check if a given number is a power of two.
+ *
+ * @param n     The number to check.
+ *
+ * @return      true if it is a power of two, false otherwise.
+ */
+static bool
+is_power_of_two(uint32_t n)
+{
+        if (n == 0)
+                return false;
+
+        return (n & (n - 1)) == 0;
 }