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

Timestamp:

2008-11-18T20:28:17Z (17 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_ops.c (modified) (10 diffs)

uspace/srv/fs/fat/fat_ops.c

@@ -90 +90 @@
         /* Read the block that contains the dentry of interest. */
         b = _fat_block_get(bs, node->idx->dev_handle, node->idx->pfc,
-            (node->idx->pdi * sizeof(fat_dentry_t)) / bps);
+            (node->idx->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE);
 
         d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
@@ -182 +182 @@
         /* Read the block that contains the dentry of interest. */
         b = _fat_block_get(bs, idxp->dev_handle, idxp->pfc,
-            (idxp->pdi * sizeof(fat_dentry_t)) / bps);
+            (idxp->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE);
         assert(b);
 
@@ -283 +283 @@
         blocks = parentp->size / bps;
         for (i = 0; i < blocks; i++) {
-                b = fat_block_get(bs, parentp, i);
+                b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE);
                 for (j = 0; j < dps; j++) { 
                         d = ((fat_dentry_t *)b->data) + j;
@@ -373 +373 @@
                 fat_dentry_t *d;
         
-                b = fat_block_get(bs, nodep, i);
+                b = fat_block_get(bs, nodep, i, BLOCK_FLAGS_NONE);
                 for (j = 0; j < dps; j++) {
                         d = ((fat_dentry_t *)b->data) + j;
@@ -575 +575 @@
                         bytes = min(len, bps - pos % bps);
                         bytes = min(bytes, nodep->size - pos);
-                        b = fat_block_get(bs, nodep, pos / bps);
+                        b = fat_block_get(bs, nodep, pos / bps,
+                            BLOCK_FLAGS_NONE);
                         (void) ipc_data_read_finalize(callid, b->data + pos % bps,
                             bytes);
@@ -600 +601 @@
                         off_t o;
 
-                        b = fat_block_get(bs, nodep, bnum);
+                        b = fat_block_get(bs, nodep, bnum, BLOCK_FLAGS_NONE);
                         for (o = pos % (bps / sizeof(fat_dentry_t));
                             o < bps / sizeof(fat_dentry_t);
@@ -648 +649 @@
         unsigned bpc;           /* bytes per cluster */
         off_t boundary;
+        int flags = BLOCK_FLAGS_NONE;
         
         if (!nodep) {
@@ -676 +678 @@
          */ 
         bytes = min(len, bps - pos % bps);
+        if (bytes == bps)
+                flags |= BLOCK_FLAGS_NOREAD;
         
         boundary = ROUND_UP(nodep->size, bpc);
@@ -686 +690 @@
                  */
                 fat_fill_gap(bs, nodep, FAT_CLST_RES0, pos);
-                b = fat_block_get(bs, nodep, pos / bps);
+                b = fat_block_get(bs, nodep, pos / bps, flags);
                 (void) ipc_data_write_finalize(callid, b->data + pos % bps,
                     bytes);
@@ -719 +723 @@
                 /* zero fill any gaps */
                 fat_fill_gap(bs, nodep, mcl, pos);
-                b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc);
+                b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc,
+                    flags);
                 (void) ipc_data_write_finalize(callid, b->data + pos % bps,
                     bytes);