WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat_fat.c

 #include <byteorder.h>
 #include <align.h>
 #include <assert.h>
 block_t *
-_fat_block_get(dev_handle_t dev_handle, fat_cluster_t firstc, off_t offset)
+_fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
+    off_t offset)
+{
-    block_t *bb;
     block_t *b;
     unsigned bps;
     unsigned spc;
     unsigned rscnt;     /* block address of the first FAT */
     unsigned fatcnt;
     unsigned ssa;       /* size of the system area */
     unsigned clusters;
     fat_cluster_t clst = firstc;
     unsigned i;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
+    bps = uint16_t_le2host(bs->bps);
-    spc = FAT_BS(bb)->spc;
+    spc = bs->spc;
-    rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
+    rscnt = uint16_t_le2host(bs->rscnt);
-    fatcnt = FAT_BS(bb)->fatcnt;
+    fatcnt = bs->fatcnt;
-    rde = uint16_t_le2host(FAT_BS(bb)->root_ent_max);
+    rde = uint16_t_le2host(bs->root_ent_max);
-    sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
+    sf = uint16_t_le2host(bs->sec_per_fat);
-    block_put(bb);
     rds = (sizeof(fat_dentry_t) * rde) / bps;
     rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
     ssa = rscnt + fatcnt * sf + rds;
     return b;
+}
 /** Return number of blocks allocated to a file.
+ *
+ * @param bs        Buffer holding the boot sector for the file.
  * @param dev_handle    Device handle of the device with the file.
  * @param firstc    First cluster of the file.
  * @param lastc     If non-NULL, output argument holding the
  *          last cluster.
+ *
  * @return      Number of blocks allocated to the file.
  */
 uint16_t
-_fat_blcks_get(dev_handle_t dev_handle, fat_cluster_t firstc,
+_fat_blcks_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
     fat_cluster_t *lastc)
+{
-    block_t *bb;
     block_t *b;
     unsigned bps;
     unsigned spc;
     unsigned rscnt;     /* block address of the first FAT */
     unsigned clusters = 0;
     fat_cluster_t clst = firstc;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
+    bps = uint16_t_le2host(bs->bps);
-    spc = FAT_BS(bb)->spc;
+    spc = bs->spc;
-    rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
+    rscnt = uint16_t_le2host(bs->rscnt);
-    block_put(bb);
     if (firstc == FAT_CLST_RES0) {
         /* No space allocated to the file. */
         if (lastc)
             *lastc = firstc;
     if (lastc)
         *lastc = clst;
     return clusters * spc;
+}
-uint16_t fat_bps_get(dev_handle_t dev_handle)
-{
-    block_t *bb;
-    uint16_t bps;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    assert(bb != NULL);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
-    block_put(bb);
-    return bps;
-}
 /** Fill the gap between EOF and a new file position.
+ *
+ * @param bs        Buffer holding the boot sector for nodep.
  * @param nodep     FAT node with the gap.
  * @param mcl       First cluster in an independent cluster chain that will
  *          be later appended to the end of the node's own cluster
  *          chain. If pos is still in the last allocated cluster,
  *          this argument is ignored.
  * @param pos       Position in the last node block.
  */
-void fat_fill_gap(fat_node_t *nodep, fat_cluster_t mcl, off_t pos)
+void fat_fill_gap(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl, off_t pos)
+{
     uint16_t bps;
     unsigned spc;
-    block_t *bb, *b;
+    block_t *b;
     off_t o, boundary;
-    bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
+    bps = uint16_t_le2host(bs->bps);
-    spc = FAT_BS(bb)->spc;
+    spc = bs->spc;
-    block_put(bb);
     boundary = ROUND_UP(nodep->size, bps * spc);
     /* zero out already allocated space */
     for (o = nodep->size - 1; o < pos && o < boundary;
         o = ALIGN_DOWN(o + bps, bps)) {
-        b = fat_block_get(nodep, o / bps);
+        b = fat_block_get(bs, nodep, o / bps);
         memset(b->data + o % bps, 0, bps - o % bps);
         b->dirty = true;        /* need to sync node */
         block_put(b);
+    }
     if (o >= pos)
         return;
     /* zero out the initial part of the new cluster chain */
     for (o = boundary; o < pos; o += bps) {
-        b = _fat_block_get(nodep->idx->dev_handle, mcl,
+        b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,
             (o - boundary) / bps);
         memset(b->data, 0, min(bps, pos - o));
         b->dirty = true;        /* need to sync node */
         block_put(b);
+    }
+}
 void
-fat_mark_cluster(dev_handle_t dev_handle, unsigned fatno, fat_cluster_t clst,
+fat_mark_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno,
-    fat_cluster_t value)
+    fat_cluster_t clst, fat_cluster_t value)
+{
-    block_t *bb, *blk;
+    block_t *b;
     uint16_t bps;
     uint16_t rscnt;
     uint16_t sf;
-    uint8_t fatcnt;
     fat_cluster_t *cp;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
+    bps = uint16_t_le2host(bs->bps);
-    rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
+    rscnt = uint16_t_le2host(bs->rscnt);
-    sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
+    sf = uint16_t_le2host(bs->sec_per_fat);
-    fatcnt = FAT_BS(bb)->fatcnt;
-    block_put(bb);
-    assert(fatno < fatcnt);
+    assert(fatno < bs->fatcnt);
-    blk = block_get(dev_handle, rscnt + sf * fatno +
+    b = block_get(dev_handle, rscnt + sf * fatno +
         (clst * sizeof(fat_cluster_t)) / bps, bps);
-    cp = (fat_cluster_t *)blk->data + clst % (bps / sizeof(fat_cluster_t));
+    cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
     *cp = host2uint16_t_le(value);
-    blk->dirty = true;      /* need to sync block */
+    b->dirty = true;        /* need to sync block */
-    block_put(blk);
+    block_put(b);
+}
-void fat_alloc_shadow_clusters(dev_handle_t dev_handle, fat_cluster_t *lifo,
+void fat_alloc_shadow_clusters(fat_bs_t *bs, dev_handle_t dev_handle,
-    unsigned nclsts)
+    fat_cluster_t *lifo, unsigned nclsts)
+{
-    uint8_t fatcnt;
     uint8_t fatno;
     unsigned c;
-    block_t *bb;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    fatcnt = FAT_BS(bb)->fatcnt;
-    block_put(bb);
-    for (fatno = FAT1 + 1; fatno < fatcnt; fatno++) {
+    for (fatno = FAT1 + 1; fatno < bs->fatcnt; fatno++) {
         for (c = 0; c < nclsts; c++) {
-            fat_mark_cluster(dev_handle, fatno, lifo[c],
+            fat_mark_cluster(bs, dev_handle, fatno, lifo[c],
                 c == 0 ? FAT_CLST_LAST1 : lifo[c - 1]);
+        }
+    }
+}
 int
-fat_alloc_clusters(dev_handle_t dev_handle, unsigned nclsts, fat_cluster_t *mcl,
+fat_alloc_clusters(fat_bs_t *bs, dev_handle_t dev_handle, unsigned nclsts,
-    fat_cluster_t *lcl)
+    fat_cluster_t *mcl, fat_cluster_t *lcl)
+{
     uint16_t bps;
     uint16_t rscnt;
     uint16_t sf;
-    block_t *bb, *blk;
+    block_t *blk;
     fat_cluster_t *lifo;    /* stack for storing free cluster numbers */
     unsigned found = 0; /* top of the free cluster number stack */
     unsigned b, c, cl;
     lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t));
     if (lifo)
         return ENOMEM;
-    bb = block_get(dev_handle, BS_BLOCK, BS_SIZE);
-    bps = uint16_t_le2host(FAT_BS(bb)->bps);
+    bps = uint16_t_le2host(bs->bps);
-    rscnt = uint16_t_le2host(FAT_BS(bb)->rscnt);
+    rscnt = uint16_t_le2host(bs->rscnt);
-    sf = uint16_t_le2host(FAT_BS(bb)->sec_per_fat);
+    sf = uint16_t_le2host(bs->sec_per_fat);
-    block_put(bb);
     /*
      * Search FAT1 for unused clusters.
      */
     for (b = 0, cl = 0; b < sf; blk++) {
                 blk->dirty = true;  /* need to sync block */
                 if (++found == nclsts) {
                     /* we are almost done */
                     block_put(blk);
                     /* update the shadow copies of FAT */
-                    fat_alloc_shadow_clusters(dev_handle,
+                    fat_alloc_shadow_clusters(bs,
-                        lifo, nclsts);
+                        dev_handle, lifo, nclsts);
                     *mcl = lifo[found - 1];
                     *lcl = lifo[0];
                     free(lifo);
                     return EOK;
+                }
     /*
      * We could not find enough clusters. Now we need to free the clusters
      * we have allocated so far.
      */
-    while (found--)
+    while (found--) {
-        fat_mark_cluster(dev_handle, FAT1, lifo[found], FAT_CLST_RES0);
+        fat_mark_cluster(bs, dev_handle, FAT1, lifo[found],
+            FAT_CLST_RES0);
+    }
     free(lifo);
     return ENOSPC;
+}
-void fat_append_clusters(fat_node_t *nodep, fat_cluster_t mcl)
+void fat_append_clusters(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl)
+{
-    block_t *bb;
+    dev_handle_t dev_handle = nodep->idx->dev_handle;
     fat_cluster_t lcl;
-    uint8_t fatcnt, fatno;
+    uint8_t fatno;
-    if (_fat_blcks_get(nodep->idx->dev_handle, nodep->firstc, &lcl) == 0) {
+    if (_fat_blcks_get(bs, dev_handle, nodep->firstc, &lcl) == 0) {
         nodep->firstc = host2uint16_t_le(mcl);
         nodep->dirty = true;        /* need to sync node */
         return;
+    }
-    bb = block_get(nodep->idx->dev_handle, BS_BLOCK, BS_SIZE);
-    fatcnt = FAT_BS(bb)->fatcnt;
-    block_put(bb);
-    for (fatno = FAT1; fatno < fatcnt; fatno++)
+    for (fatno = FAT1; fatno < bs->fatcnt; fatno++)
-        fat_mark_cluster(nodep->idx->dev_handle, fatno, lcl, mcl);
+        fat_mark_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl);
+}
 /**
  * @}
  */

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_fat.c – Rev 3513 → 3516