2015-08-19 11:15:55

by Chao Yu

[permalink] [raw]
Subject: [PATCH 7/9] f2fs: split __insert_extent_tree_ret for readability

This patch splits __insert_extent_tree_ret into __try_merge_extent_node &
__insert_extent_tree for code readability.

Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/extent_cache.c | 49 +++++++++++++++++++++++++++++--------------------
1 file changed, 29 insertions(+), 20 deletions(-)

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 5b6139f..ab26728 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -294,29 +294,22 @@ static struct extent_node *__lookup_extent_tree_ret(struct extent_tree *et,
return NULL;
}

-static struct extent_node *__insert_extent_tree_ret(struct f2fs_sb_info *sbi,
+static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
struct extent_tree *et, struct extent_info *ei,
struct extent_node **den,
struct extent_node *prev_ex,
- struct extent_node *next_ex,
- struct rb_node **insert_p,
- struct rb_node *insert_parent)
+ struct extent_node *next_ex)
{
- struct rb_node **p = &et->root.rb_node;
- struct rb_node *parent = NULL;
struct extent_node *en = NULL;
- int merged = 0;

if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
- f2fs_bug_on(sbi, !den);
- merged = 1;
prev_ex->ei.len += ei->len;
ei = &prev_ex->ei;
en = prev_ex;
}
+
if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
- f2fs_bug_on(sbi, !den);
- if (merged++) {
+ if (en) {
__detach_extent_node(sbi, et, prev_ex);
*den = prev_ex;
}
@@ -325,8 +318,23 @@ static struct extent_node *__insert_extent_tree_ret(struct f2fs_sb_info *sbi,
next_ex->ei.len += ei->len;
en = next_ex;
}
- if (merged)
- goto update_out;
+
+ if (en) {
+ if (en->ei.len > et->largest.len)
+ et->largest = en->ei;
+ et->cached_en = en;
+ }
+ return en;
+}
+
+static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
+ struct extent_tree *et, struct extent_info *ei,
+ struct rb_node **insert_p,
+ struct rb_node *insert_parent)
+{
+ struct rb_node **p = &et->root.rb_node;
+ struct rb_node *parent = NULL;
+ struct extent_node *en = NULL;

if (insert_p && insert_parent) {
parent = insert_parent;
@@ -349,7 +357,7 @@ do_insert:
en = __attach_extent_node(sbi, et, ei, parent, p);
if (!en)
return NULL;
-update_out:
+
if (en->ei.len > et->largest.len)
et->largest = en->ei;
et->cached_en = en;
@@ -401,8 +409,7 @@ static bool f2fs_update_extent_tree(struct inode *inode, pgoff_t fofs,
if (fofs - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
set_extent_info(&ei, dei.fofs, dei.blk,
fofs - dei.fofs);
- en1 = __insert_extent_tree_ret(sbi, et, &ei, NULL,
- NULL, NULL, NULL, NULL);
+ en1 = __insert_extent_tree(sbi, et, &ei, NULL, NULL);
}

/* insert right part of split extent into cache */
@@ -410,8 +417,7 @@ static bool f2fs_update_extent_tree(struct inode *inode, pgoff_t fofs,
if (endofs - fofs >= F2FS_MIN_EXTENT_LEN) {
set_extent_info(&ei, fofs + 1,
fofs - dei.fofs + dei.blk + 1, endofs - fofs);
- en2 = __insert_extent_tree_ret(sbi, et, &ei, NULL,
- NULL, NULL, NULL, NULL);
+ en2 = __insert_extent_tree(sbi, et, &ei, NULL, NULL);
}
}

@@ -419,8 +425,11 @@ update_extent:
/* 3. update extent in extent cache */
if (blkaddr) {
set_extent_info(&ei, fofs, blkaddr, 1);
- en3 = __insert_extent_tree_ret(sbi, et, &ei, &den,
- prev_ex, next_ex, insert_p, insert_parent);
+ en3 = __try_merge_extent_node(sbi, et, &ei, &den,
+ prev_ex, next_ex);
+ if (!en3)
+ en3 = __insert_extent_tree(sbi, et, &ei,
+ insert_p, insert_parent);

/* give up extent_cache, if split and small updates happen */
if (dei.len >= 1 &&
--
2.4.2