Changeset 1d8cdb1 in mainline for uspace/srv/fs/fat/fat_fat.c

Timestamp:

2008-11-18T20:28:17Z (16 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

18c485a

Parents:

26fa0f9f

Message:

Avoid unnecessary block reads in block_get().

File:

• uspace/srv/fs/fat/fat_fat.c (modified) (10 diffs)

uspace/srv/fs/fat/fat_fat.c

@@ -95 +95 @@
                 fidx = clst % (bps / sizeof(fat_cluster_t));
                 /* read FAT1 */
-                b = block_get(dev_handle, rscnt + fsec);
+                b = block_get(dev_handle, rscnt + fsec, BLOCK_FLAGS_NONE);
                 clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
                 assert(clst != FAT_CLST_BAD);
@@ -115 +115 @@
  *                      is empty.
  * @param bn            Block number.
+ * @param flags         Flags passed to libblock.
  *
  * @return              Block structure holding the requested block.
@@ -120 +121 @@
 block_t *
 _fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
-    bn_t bn)
+    bn_t bn, int flags)
 {
         block_t *b;
@@ -144 +145 @@
                 /* root directory special case */
                 assert(bn < rds);
-                b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn);
+                b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn, flags);
                 return b;
         }
@@ -154 +155 @@
 
         b = block_get(dev_handle, ssa + (lastc - FAT_CLST_FIRST) * bs->spc +
-            bn % bs->spc);
+            bn % bs->spc, flags);
 
         return b;
@@ -184 +185 @@
         for (o = nodep->size - 1; o < pos && o < boundary;
             o = ALIGN_DOWN(o + bps, bps)) {
-                b = fat_block_get(bs, nodep, o / bps);
+                int flags = (o % bps == 0) ?
+                    BLOCK_FLAGS_NOREAD : BLOCK_FLAGS_NONE;
+                b = fat_block_get(bs, nodep, o / bps, flags);
                 memset(b->data + o % bps, 0, bps - o % bps);
                 b->dirty = true;                /* need to sync node */
@@ -196 +199 @@
         for (o = boundary; o < pos; o += bps) {
                 b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,
-                    (o - boundary) / bps);
+                    (o - boundary) / bps, BLOCK_FLAGS_NOREAD);
                 memset(b->data, 0, min(bps, pos - o));
                 b->dirty = true;                /* need to sync node */
@@ -222 +225 @@
         rscnt = uint16_t_le2host(bs->rscnt);
 
-        b = block_get(dev_handle, rscnt + (clst * sizeof(fat_cluster_t)) / bps);
+        b = block_get(dev_handle, rscnt + (clst * sizeof(fat_cluster_t)) / bps,
+            BLOCK_FLAGS_NONE);
         cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
         value = uint16_t_le2host(*cp);
@@ -254 +258 @@
         assert(fatno < bs->fatcnt);
         b = block_get(dev_handle, rscnt + sf * fatno +
-            (clst * sizeof(fat_cluster_t)) / bps);
+            (clst * sizeof(fat_cluster_t)) / bps, BLOCK_FLAGS_NONE);
         cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
         *cp = host2uint16_t_le(value);
@@ -324 +328 @@
         futex_down(&fat_alloc_lock);
         for (b = 0, cl = 0; b < sf; blk++) {
-                blk = block_get(dev_handle, rscnt + b);
+                blk = block_get(dev_handle, rscnt + b, BLOCK_FLAGS_NOREAD);
                 for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {
                         fat_cluster_t *clst = (fat_cluster_t *)blk->data + c;