Changeset 78de7be2 in mainline for uspace/app/mkexfat/mkexfat.c

Timestamp:

2012-02-24T21:30:20Z (12 years ago)

Author:

Maurizio Lombardi <m.lombardi85@…>

Branches:

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

Children:

69f9cf5

Parents:

7f381e5

Message:

mkexfat: Add function to allocate chains of clusters, alloc clusters for the bitmap and the upcase table

File:

• uspace/app/mkexfat/mkexfat.c (modified) (5 diffs)

uspace/app/mkexfat/mkexfat.c

@@ -74 +74 @@
 /** The default size of each cluster is 4096 byte */
 #define DEFAULT_CLUSTER_SIZE 4096
+
+/** Index of the first free cluster on the device */
+#define FIRST_FREE_CLUSTER   2
 
 typedef struct exfat_cfg {
@@ -348 +351 @@
                 goto error;
 
-        memset(pfat, 0, 2 * sizeof(uint32_t));
+        pfat[0] = pfat[1] = 0;
 
         for (i = 1; i < cfg->fat_sector_count; ++i) {
@@ -359 +362 @@
 error:
         free(pfat);
+        return rc;
+}
+
+/** Allocate a given number of clusters and create a cluster chain.
+ *
+ * @param service_id  The service id.
+ * @param cfg  Pointer to the exfat configuration number.
+ * @param cur_cls  Cluster index from where to start the allocation.
+ * @param ncls  Number of clusters to allocate.
+ * @return EOK on success or a negative error code.
+ */
+static int
+fat_allocate_clusters(service_id_t service_id, exfat_cfg_t *cfg,
+    uint32_t cur_cls, unsigned long ncls)
+{
+        int rc;
+        aoff64_t fat_sec = cur_cls / sizeof(uint32_t) + FAT_SECTOR_START;
+        unsigned const fat_entries = cfg->sector_size / sizeof(uint32_t);
+        uint32_t *fat;
+
+        cur_cls %= fat_entries;
+
+        fat = malloc(cfg->sector_size);
+        if (!fat)
+                return ENOMEM;
+
+loop:
+        rc = block_read_direct(service_id, fat_sec, 1, fat);
+        if (rc != EOK)
+                goto exit;
+
+        assert(fat[cur_cls] == 0);
+        assert(ncls > 0);
+
+        if (ncls == 1) {
+                fat[cur_cls] = host2uint32_t_le(0xFFFFFFFF);
+                rc = block_write_direct(service_id, fat_sec, 1, fat);
+                goto exit;
+        }
+
+        for (; cur_cls < fat_entries && ncls > 1; ++cur_cls, --ncls)
+                fat[cur_cls] = host2uint32_t_le(cur_cls + 1);
+
+        if (cur_cls == fat_entries) {
+                rc = block_write_direct(service_id, fat_sec++, 1, fat);
+                if (rc != EOK)
+                        goto exit;
+                cur_cls = 0;
+                goto loop;
+        } else if (ncls == 1)
+                fat[cur_cls] = host2uint32_t_le(0xFFFFFFFF);
+
+        rc = block_write_direct(service_id, fat_sec, 1, fat);
+
+exit:
+        free(fat);
         return rc;
 }
@@ -458 +517 @@
 {
         exfat_cfg_t cfg;
+        uint32_t next_cls;
         char *dev_path;
         service_id_t service_id;
@@ -532 +592 @@
         }
 
+        /* Allocate clusters for the bitmap */
+        rc = fat_allocate_clusters(service_id, &cfg, FIRST_FREE_CLUSTER,
+            div_round_up(cfg.bitmap_size, cfg.cluster_size));
+        if (rc != EOK) {
+                printf(NAME ": Error, failed to allocate clusters for bitmap.\n");
+                return 2;
+        }
+
+        next_cls = FIRST_FREE_CLUSTER +
+            div_round_up(cfg.bitmap_size, cfg.cluster_size);
+
+        /* Allocate clusters for the upcase table */
+        rc = fat_allocate_clusters(service_id, &cfg, next_cls,
+            div_round_up(sizeof(upcase_table), cfg.cluster_size));
+        if (rc != EOK) {
+                printf(NAME ":Error, failed to allocate clusters foe the upcase table.\n");
+                return 2;
+        }
+
         return 0;
 }