Changeset 6c8d267 in mainline

Timestamp:

2008-11-09T14:12:20Z (16 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

913a821c

Parents:

24d6efc

Message:

Simplify the fat_cluster_walk() interface.
Introduce the bn_t type for holding block offsets.

Location:

uspace

Files:

• lib/libblock/libblock.c (modified) (1 diff)
• lib/libblock/libblock.h (modified) (3 diffs)
• srv/fs/fat/fat_fat.c (modified) (8 diffs)
• srv/fs/fat/fat_fat.h (modified) (2 diffs)

uspace/lib/libblock/libblock.c

@@ -300 +300 @@
  * @return                      Block structure.
  */
-block_t *block_get(dev_handle_t dev_handle, off_t boff)
+block_t *block_get(dev_handle_t dev_handle, bn_t boff)
 {
         devcon_t *devcon;

uspace/lib/libblock/libblock.h

@@ -45 +45 @@
 #include <libadt/list.h>
 
+typedef unsigned bn_t;  /**< Block number type. */
+
 typedef struct block {
         /** Futex protecting the reference count. */
@@ -57 +59 @@
         dev_handle_t dev_handle;
         /** Block offset on the block device. Counted in 'size'-byte blocks. */
-        off_t boff;
+        bn_t boff;
         /** Size of the block. */
         size_t size;
@@ -76 +78 @@
 extern int block_cache_init(dev_handle_t, size_t, unsigned);
 
-extern block_t *block_get(dev_handle_t, off_t);
+extern block_t *block_get(dev_handle_t, bn_t);
 extern void block_put(block_t *);
 

uspace/srv/fs/fat/fat_fat.c

@@ -60 +60 @@
  * @param dev_handle    Device handle of the device with the file.
  * @param firstc        First cluster to start the walk with.
- * @param penult        If non-NULL, output argument hodling the
- *                      the penultimate cluster visited.
- * @param ult           If non-NULL, output argument holding the
- *                      ultimate cluster visited.
+ * @param lastc         If non-NULL, output argument hodling the last cluster number visited.
  * @param max_clusters  Maximum number of clusters to visit.    
  *
@@ -70 +67 @@
 uint16_t 
 fat_cluster_walk(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
-    fat_cluster_t *penult, fat_cluster_t *ult, uint16_t max_clusters)
+    fat_cluster_t *lastc, uint16_t max_clusters)
 {
         block_t *b;
@@ -83 +80 @@
         if (firstc == FAT_CLST_RES0) {
                 /* No space allocated to the file. */
-                if (ult)
-                        *ult = firstc;
+                if (lastc)
+                        *lastc = firstc;
                 return 0;
         }
 
-        /* At this point, the meaning of penult is not well-defined. */
-        if (penult)
-                *penult = FAT_CLST_RES0;
-
         while (clst < FAT_CLST_LAST1 && clusters < max_clusters) {
-                unsigned fsec;  /* sector offset relative to FAT1 */
+                bn_t fsec;      /* sector offset relative to FAT1 */
                 unsigned fidx;  /* FAT1 entry index */
 
                 assert(clst >= FAT_CLST_FIRST);
-                if (penult)
-                        *penult = clst; /* remember the penultimate cluster */
+                if (lastc)
+                        *lastc = clst;  /* remember the last cluster number */
                 fsec = (clst * sizeof(fat_cluster_t)) / bps;
                 fidx = clst % (bps / sizeof(fat_cluster_t));
@@ -109 +102 @@
         }
 
-        if (ult)
-                *ult = clst;
+        if (lastc && clst < FAT_CLST_LAST1)
+                *lastc = clst;
 
         return clusters;
@@ -121 +114 @@
  * @param firstc        First cluster used by the file. Can be zero if the file
  *                      is empty.
- * @param offset        Offset in blocks.
+ * @param bn            Block number.
  *
  * @return              Block structure holding the requested block.
@@ -127 +120 @@
 block_t *
 _fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
-    off_t offset)
+    bn_t bn)
 {
         block_t *b;
@@ -150 +143 @@
         if (firstc == FAT_CLST_ROOT) {
                 /* root directory special case */
-                assert(offset < rds);
-                b = block_get(dev_handle, rscnt + bs->fatcnt * sf + offset);
+                assert(bn < rds);
+                b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn);
                 return b;
         }
 
-        max_clusters = offset / bs->spc;
-        clusters = fat_cluster_walk(bs, dev_handle, firstc, NULL, &lastc,
+        max_clusters = bn / bs->spc;
+        clusters = fat_cluster_walk(bs, dev_handle, firstc, &lastc,
             max_clusters);
         assert(clusters == max_clusters);
 
         b = block_get(dev_handle, ssa + (lastc - FAT_CLST_FIRST) * bs->spc +
-            offset % bs->spc);
+            bn % bs->spc);
 
         return b;
@@ -362 +355 @@
 
         if (fat_cluster_walk(bs, nodep->idx->dev_handle, nodep->firstc, &lcl,
-            NULL, (uint16_t) -1) == 0) {
+            (uint16_t) -1) == 0) {
                 /* No clusters allocated to the node yet. */
                 nodep->firstc = host2uint16_t_le(mcl);

uspace/srv/fs/fat/fat_fat.h

@@ -36 +36 @@
 #include "../../vfs/vfs.h"
 #include <stdint.h>
+#include <libblock.h>
 
 #define FAT1            0
@@ -59 +60 @@
 
 #define fat_clusters_get(bs, dh, fc) \
-    fat_cluster_walk((bs), (dh), (fc), NULL, NULL, (uint16_t) -1)
-#define fat_block_get(bs, np, off) \
-    _fat_block_get((bs), (np)->idx->dev_handle, (np)->firstc, (off))
+    fat_cluster_walk((bs), (dh), (fc), NULL, (uint16_t) -1)
+extern uint16_t fat_cluster_walk(struct fat_bs *, dev_handle_t, fat_cluster_t,
+    fat_cluster_t *, uint16_t);
+
+#define fat_block_get(bs, np, bn) \
+    _fat_block_get((bs), (np)->idx->dev_handle, (np)->firstc, (bn))
 
 extern struct block *_fat_block_get(struct fat_bs *, dev_handle_t,
-    fat_cluster_t, off_t);
-extern uint16_t fat_cluster_walk(struct fat_bs *, dev_handle_t, fat_cluster_t,
-    fat_cluster_t *, fat_cluster_t *, uint16_t);
+    fat_cluster_t, bn_t);
   
 extern void fat_append_clusters(struct fat_bs *, struct fat_node *,