Changeset a9a0982 in mainline

Timestamp:

2011-11-01T13:52:19Z (13 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

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

Children:

d5a78e28

Parents:

c25e39b

Message:

performace improvement

Location:

uspace/lib/ext4

Files:

• libext4_filesystem.c (modified) (7 diffs)
• libext4_filesystem.h (modified) (1 diff)

uspace/lib/ext4/libext4_filesystem.c

@@ -43 +43 @@
 int ext4_filesystem_init(ext4_filesystem_t *fs, service_id_t service_id)
 {
-
         int rc;
         ext4_superblock_t *temp_superblock;
         size_t block_size;
+        uint32_t block_ids_per_block;
+        int i;
 
         fs->device = service_id;
@@ -75 +76 @@
                 block_fini(fs->device);
                 return rc;
+        }
+
+        block_ids_per_block = block_size / sizeof(uint32_t);
+        fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
+        fs->inode_blocks_per_level[0] = 1;
+        for (i = 1; i < 4; i++) {
+                fs->inode_blocks_per_level[i]  = fs->inode_blocks_per_level[i-1] *
+                    block_ids_per_block;
+                fs->inode_block_limits[i] = fs->inode_block_limits[i-1] +
+                                fs->inode_blocks_per_level[i];
         }
 
@@ -261 +272 @@
 {
         int rc;
-        aoff64_t limits[4];
-        uint32_t block_ids_per_block;
-        aoff64_t blocks_per_level[4];
         uint32_t offset_in_block;
         uint32_t current_block;
@@ -287 +295 @@
         }
 
-        /* Compute limits for indirect block levels
-         * TODO: compute this once when loading filesystem and store in ext2_filesystem_t
-         */
-        block_ids_per_block = ext4_superblock_get_block_size(fs->superblock) / sizeof(uint32_t);
-        limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
-        blocks_per_level[0] = 1;
-        for (i = 1; i < 4; i++) {
-                blocks_per_level[i]  = blocks_per_level[i-1] *
-                    block_ids_per_block;
-                limits[i] = limits[i-1] + blocks_per_level[i];
-        }
-
         /* Determine the indirection level needed to get the desired block */
         level = -1;
         for (i = 1; i < 4; i++) {
-                if (iblock < limits[i]) {
+                if (iblock < fs->inode_block_limits[i]) {
                         level = i;
                         break;
@@ -313 +309 @@
 
         /* Compute offsets for the topmost level */
-        block_offset_in_level = iblock - limits[level-1];
+        block_offset_in_level = iblock - fs->inode_block_limits[level-1];
         current_block = ext4_inode_get_indirect_block(inode, level-1);
-        offset_in_block = block_offset_in_level / blocks_per_level[level-1];
+        offset_in_block = block_offset_in_level / fs->inode_blocks_per_level[level-1];
 
         /* Navigate through other levels, until we find the block number
@@ -326 +322 @@
                 }
 
-                assert(offset_in_block < block_ids_per_block);
                 current_block = uint32_t_le2host(((uint32_t*)block->data)[offset_in_block]);
 
@@ -350 +345 @@
 
                 /* Visit the next level */
-                block_offset_in_level %= blocks_per_level[level];
-                offset_in_block = block_offset_in_level / blocks_per_level[level-1];
+                block_offset_in_level %= fs->inode_blocks_per_level[level];
+                offset_in_block = block_offset_in_level / fs->inode_blocks_per_level[level-1];
         }
 

uspace/lib/ext4/libext4_filesystem.h

@@ -42 +42 @@
         service_id_t device;
         ext4_superblock_t *     superblock;
+        aoff64_t inode_block_limits[4];
+        aoff64_t inode_blocks_per_level[4];
 } ext4_filesystem_t;