]> git.karo-electronics.de Git - karo-tx-uboot.git/blobdiff - fs/ext4/ext4_common.c
ext4fs: Add ext4 extent cache for read operations
[karo-tx-uboot.git] / fs / ext4 / ext4_common.c
index 02da75c084048396085fb9c288882c906c5b0e18..6584892dd28de4d0a5f5aa31e230fe3b5ebb0293 100644 (file)
@@ -26,6 +26,7 @@
 #include <stddef.h>
 #include <linux/stat.h>
 #include <linux/time.h>
+#include <linux/list.h>
 #include <asm/byteorder.h>
 #include "ext4_common.h"
 
@@ -44,6 +45,14 @@ int ext4fs_indir3_blkno = -1;
 struct ext2_inode *g_parent_inode;
 static int symlinknest;
 
+struct ext4_extent_node {
+       uint32_t block;
+       uint16_t len;
+       uint64_t start;
+       struct list_head lh;
+};
+static LIST_HEAD(ext4_extent_lh);
+
 #if defined(CONFIG_EXT4_WRITE)
 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
 {
@@ -1407,45 +1416,102 @@ void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
 
 #endif
 
-static struct ext4_extent_header *ext4fs_get_extent_block
-       (struct ext2_data *data, char *buf,
-               struct ext4_extent_header *ext_block,
-               uint32_t fileblock, int log2_blksz)
+static void ext4fs_extent_cache_insert(struct ext4_extent_node *new)
+{
+       struct ext4_extent_node *node;
+
+       list_for_each_entry(node, &ext4_extent_lh, lh)
+               if (node->block > new->block) {
+                       list_add_tail(&new->lh, &node->lh);
+                       return;
+               }
+       list_add_tail(&new->lh, &ext4_extent_lh);
+}
+
+static int __ext4fs_build_extent_cache(struct ext2_data *data,
+               struct ext4_extent_header *ext_block)
 {
+       int blksz = EXT2_BLOCK_SIZE(data);
+       int log2_blksz = LOG2_BLOCK_SIZE(data)
+               - get_fs()->dev_desc->log2blksz;
+       struct ext4_extent_node *node;
        struct ext4_extent_idx *index;
+       struct ext4_extent *extent;
        unsigned long long block;
-       int blksz = EXT2_BLOCK_SIZE(data);
-       int i;
+       char *buf;
+       int i, err;
 
-       while (1) {
-               index = (struct ext4_extent_idx *)(ext_block + 1);
+       if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
+               return -EINVAL;
 
-               if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
-                       return 0;
-
-               if (ext_block->eh_depth == 0)
-                       return ext_block;
-               i = -1;
-               do {
-                       i++;
-                       if (i >= le16_to_cpu(ext_block->eh_entries))
-                               break;
-               } while (fileblock >= le32_to_cpu(index[i].ei_block));
+       if (ext_block->eh_depth == 0) {
+               extent = (struct ext4_extent *)(ext_block + 1);
+               for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
+                       node = malloc(sizeof(*node));
+                       if (!node)
+                               return -ENOMEM;
+                       node->block = le32_to_cpu(extent[i].ee_block);
+                       node->len = le16_to_cpu(extent[i].ee_len);
+                       node->start = le16_to_cpu(extent[i].ee_start_hi);
+                       node->start = (node->start << 32) +
+                               le32_to_cpu(extent[i].ee_start_lo);
+                       ext4fs_extent_cache_insert(node);
+               }
+               return 0;
+       }
 
-               if (--i < 0)
-                       return 0;
+       index = (struct ext4_extent_idx *)(ext_block + 1);
+       for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
+               buf = malloc(blksz);
+               if (!buf)
+                       return -ENOMEM;
 
                block = le16_to_cpu(index[i].ei_leaf_hi);
                block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
 
-               if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
-                                  buf))
-                       ext_block = (struct ext4_extent_header *)buf;
-               else
-                       return 0;
+               if (!ext4fs_devread(block << log2_blksz, 0, blksz, buf)) {
+                       free(buf);
+                       return -EIO;
+               }
+
+               err = __ext4fs_build_extent_cache(data,
+                               (struct ext4_extent_header *) buf);
+               free(buf);
+               if (err < 0)
+                       return err;
+       }
+
+       return 0;
+}
+
+int ext4fs_build_extent_cache(struct ext2_inode *inode)
+{
+       return __ext4fs_build_extent_cache(ext4fs_root,
+                       (struct ext4_extent_header *)
+                       inode->b.blocks.dir_blocks);
+}
+
+void ext4fs_free_extent_cache(void)
+{
+       struct ext4_extent_node *node, *tmp;
+
+       list_for_each_entry_safe(node, tmp, &ext4_extent_lh, lh) {
+               list_del(&node->lh);
+               free(node);
        }
 }
 
+static struct ext4_extent_node *ext4fs_extent_cache_get(uint32_t block)
+{
+       struct ext4_extent_node *node;
+
+       list_for_each_entry(node, &ext4_extent_lh, lh)
+               if (block >= node->block && block < node->block + node->len)
+                       return node;
+
+       return NULL;
+}
+
 static int ext4fs_blockgroup
        (struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
 {
@@ -1508,54 +1574,22 @@ long int read_allocated_block(struct ext2_inode *inode, int fileblock)
        long int rblock;
        long int perblock_parent;
        long int perblock_child;
-       unsigned long long start;
+
        /* get the blocksize of the filesystem */
        blksz = EXT2_BLOCK_SIZE(ext4fs_root);
        log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
                - get_fs()->dev_desc->log2blksz;
 
        if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
-               char *buf = zalloc(blksz);
-               if (!buf)
-                       return -ENOMEM;
-               struct ext4_extent_header *ext_block;
-               struct ext4_extent *extent;
-               int i = -1;
-               ext_block =
-                       ext4fs_get_extent_block(ext4fs_root, buf,
-                                               (struct ext4_extent_header *)
-                                               inode->b.blocks.dir_blocks,
-                                               fileblock, log2_blksz);
-               if (!ext_block) {
-                       printf("invalid extent block\n");
-                       free(buf);
-                       return -EINVAL;
-               }
-
-               extent = (struct ext4_extent *)(ext_block + 1);
-
-               do {
-                       i++;
-                       if (i >= le16_to_cpu(ext_block->eh_entries))
-                               break;
-               } while (fileblock >= le32_to_cpu(extent[i].ee_block));
-               if (--i >= 0) {
-                       fileblock -= le32_to_cpu(extent[i].ee_block);
-                       if (fileblock >= le16_to_cpu(extent[i].ee_len)) {
-                               free(buf);
-                               return 0;
-                       }
+               struct ext4_extent_node *node;
 
-                       start = le16_to_cpu(extent[i].ee_start_hi);
-                       start = (start << 32) +
-                                       le32_to_cpu(extent[i].ee_start_lo);
-                       free(buf);
-                       return fileblock + start;
+               node = ext4fs_extent_cache_get(fileblock);
+               if (!node) {
+                       printf("Extent Error\n");
+                       return -1;
                }
 
-               printf("Extent Error\n");
-               free(buf);
-               return -1;
+               return fileblock - node->block + node->start;
        }
 
        /* Direct blocks. */