From 715b56fe2b47e073e6f2425e0cedba0e92a4014d Mon Sep 17 00:00:00 2001
From: Tom Rini <trini@ti.com>
Date: Wed, 26 Feb 2014 08:18:58 -0500
Subject: [PATCH] Revert "ext4fs: Add ext4 extent cache for read operations"
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This reverts commit fc0fc50f38a4d7d0554558076a79dfe8b0d78cd5.
The author has asked on the mailing list that we revert this for now as
it breaks write support.
Reported-by: Åukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Tom Rini <trini@ti.com>
---
fs/ext4/ext4_common.c | 164 +++++++++++++++++-------------------------
fs/ext4/ext4_common.h | 3 -
fs/ext4/ext4fs.c | 36 +++-------
3 files changed, 73 insertions(+), 130 deletions(-)
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 6584892dd2..02da75c084 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -26,7 +26,6 @@
#include <stddef.h>
#include <linux/stat.h>
#include <linux/time.h>
-#include <linux/list.h>
#include <asm/byteorder.h>
#include "ext4_common.h"
@@ -45,14 +44,6 @@ 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)
{
@@ -1416,102 +1407,45 @@ void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
#endif
-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)
+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)
{
- 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;
- char *buf;
- int i, err;
+ int blksz = EXT2_BLOCK_SIZE(data);
+ int i;
- if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
- return -EINVAL;
+ while (1) {
+ index = (struct ext4_extent_idx *)(ext_block + 1);
- 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 (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
+ 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;
+ 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 (--i < 0)
+ return 0;
block = le16_to_cpu(index[i].ei_leaf_hi);
block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
- 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);
+ if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
+ buf))
+ ext_block = (struct ext4_extent_header *)buf;
+ else
+ return 0;
}
}
-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)
{
@@ -1574,22 +1508,54 @@ 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) {
- struct ext4_extent_node *node;
+ 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;
+ }
- node = ext4fs_extent_cache_get(fileblock);
- if (!node) {
- printf("Extent Error\n");
- return -1;
+ 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;
+ }
+
+ 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;
}
- return fileblock - node->block + node->start;
+ printf("Extent Error\n");
+ free(buf);
+ return -1;
}
/* Direct blocks. */
diff --git a/fs/ext4/ext4_common.h b/fs/ext4/ext4_common.h
index a9fd8c6573..5fa1719f2e 100644
--- a/fs/ext4/ext4_common.h
+++ b/fs/ext4/ext4_common.h
@@ -57,9 +57,6 @@ int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
struct ext2fs_node **fnode, int *ftype);
-int ext4fs_build_extent_cache(struct ext2_inode *inode);
-void ext4fs_free_extent_cache(void);
-
#if defined(CONFIG_EXT4_WRITE)
uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n);
int ext4fs_checksum_update(unsigned int i);
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 4f1b4c8bce..417ce7b63b 100644
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -63,14 +63,6 @@ int ext4fs_read_file(struct ext2fs_node *node, int pos,
char *delayed_buf = NULL;
short status;
- if (le32_to_cpu(node->inode.flags) & EXT4_EXTENTS_FL) {
- if (ext4fs_build_extent_cache(&node->inode)) {
- printf("Error building extent cache!\n");
- len = -1;
- goto out_exit;
- }
- }
-
/* Adjust len so it we can't read past the end of the file. */
if (len > filesize)
len = filesize;
@@ -83,10 +75,8 @@ int ext4fs_read_file(struct ext2fs_node *node, int pos,
int blockend = blocksize;
int skipfirst = 0;
blknr = read_allocated_block(&(node->inode), i);
- if (blknr < 0) {
- len = -1;
- goto out_exit;
- }
+ if (blknr < 0)
+ return -1;
blknr = blknr << log2_fs_blocksize;
@@ -116,10 +106,8 @@ int ext4fs_read_file(struct ext2fs_node *node, int pos,
delayed_skipfirst,
delayed_extent,
delayed_buf);
- if (status == 0) {
- len = -1;
- goto out_exit;
- }
+ if (status == 0)
+ return -1;
previous_block_number = blknr;
delayed_start = blknr;
delayed_extent = blockend;
@@ -144,10 +132,8 @@ int ext4fs_read_file(struct ext2fs_node *node, int pos,
delayed_skipfirst,
delayed_extent,
delayed_buf);
- if (status == 0) {
- len = -1;
- goto out_exit;
- }
+ if (status == 0)
+ return -1;
previous_block_number = -1;
}
memset(buf, 0, blocksize - skipfirst);
@@ -159,17 +145,11 @@ int ext4fs_read_file(struct ext2fs_node *node, int pos,
status = ext4fs_devread(delayed_start,
delayed_skipfirst, delayed_extent,
delayed_buf);
- if (status == 0) {
- len = -1;
- goto out_exit;
- }
+ if (status == 0)
+ return -1;
previous_block_number = -1;
}
-
-out_exit:
- ext4fs_free_extent_cache();
-
return len;
}
--
2.39.5