Changeset a927398 in mainline for uspace/app/mkfat/mkfat.c

Timestamp:

2017-07-02T17:03:58Z (7 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

58fa3e6

Parents:

f4ae95a

Message:

Fix FAT size computation for auto-detected FAT32.

File:

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

uspace/app/mkfat/mkfat.c

@@ -213 +213 @@
         }
 
-        printf(NAME ": Creating FAT%d filesystem on device %s.\n", cfg.fat_type, dev_path);
+        printf(NAME ": Creating FAT filesystem on device %s.\n", dev_path);
 
         rc = fat_params_compute(&cfg);
@@ -220 +220 @@
                 return 2;
         }
+
+        printf(NAME ": Filesystem type FAT%d.\n", cfg.fat_type);
 
         rc = fat_blocks_write(&cfg, service_id);
@@ -274 +276 @@
 {
         uint32_t fat_bytes;
+        uint32_t non_data_sectors_lb_16;
         uint32_t non_data_sectors_lb;
+        uint32_t rd_sectors;
+        uint32_t tot_clust_16;
 
         /*
@@ -280 +285 @@
          * system. The optimum could be potentially smaller since we
          * do not subtract size of the FAT itself when computing the
-         * size of the data region.
+         * size of the data region. Also the root dir area might not
+         * need FAT entries if we decide to make a FAT32.
          */
 
         cfg->reserved_sectors = 1 + cfg->addt_res_sectors;
-        if (cfg->fat_type != FAT32) {
-                cfg->rootdir_sectors = div_round_up(cfg->root_ent_max * DIRENT_SIZE,
-                        cfg->sector_size);
-        } else
-                cfg->rootdir_sectors = cfg->sectors_per_cluster;
-        non_data_sectors_lb = cfg->reserved_sectors + cfg->rootdir_sectors;
-
-        cfg->total_clusters = div_round_up(cfg->total_sectors - non_data_sectors_lb,
+
+        /* Only correct for FAT12/16 (FAT32 has root dir stored in clusters */
+        rd_sectors = div_round_up(cfg->root_ent_max * DIRENT_SIZE,
+                cfg->sector_size);
+        non_data_sectors_lb_16 = cfg->reserved_sectors + rd_sectors;
+
+        /* Only correct for FAT12/16 */
+        tot_clust_16 = div_round_up(cfg->total_sectors - non_data_sectors_lb_16,
             cfg->sectors_per_cluster);
 
-        if (cfg->total_clusters <= FAT12_CLST_MAX) {
+        /* Now detect FAT type */
+        if (tot_clust_16 <= FAT12_CLST_MAX) {
                 if (cfg->fat_type == FATAUTO)
                         cfg->fat_type = FAT12;
                 else if (cfg->fat_type != FAT12)
                         return EINVAL;
-        } else if (cfg->total_clusters <= FAT16_CLST_MAX) {
+        } else if (tot_clust_16 <= FAT16_CLST_MAX) {
                 if (cfg->fat_type == FATAUTO)
                         cfg->fat_type = FAT16;
@@ -310 +317 @@
                         return EINVAL;
         }
+
+        /* Actual root directory size, non-data sectors */
+        if (cfg->fat_type != FAT32) {
+                cfg->rootdir_sectors = div_round_up(cfg->root_ent_max * DIRENT_SIZE,
+                        cfg->sector_size);
+                non_data_sectors_lb = cfg->reserved_sectors + cfg->rootdir_sectors;
+
+        } else {
+                /* We create a single-cluster root dir */
+                cfg->rootdir_sectors = cfg->sectors_per_cluster;
+                non_data_sectors_lb = cfg->reserved_sectors;
+        }
+
+        /* Actual total number of clusters */
+        cfg->total_clusters = div_round_up(cfg->total_sectors - non_data_sectors_lb,
+            cfg->sectors_per_cluster);
 
         fat_bytes = div_round_up((cfg->total_clusters + 2) *