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Date: Tue, 28 Jun 2011 10:05:09 -0400
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: "Theodore Ts'o" <tytso@....edu>, Eric Sandeen <sandeen@...hat.com>
Subject: [PATCH -v3] ext4: refactor duplicated block placement code
From: "Theodore Ts'o" <tytso@....edu>
I found that ext4_ext_find_goal() and ext4_find_near()
share the same code for returning a coloured start block
based on i_block_group.
We can refactor this into a common function so that they
don't diverge in the future.
Thanks to adilger for suggesting the new function name.
Signed-off-by: Eric Sandeen <sandeen@...hat.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
---
Moved new code to balloc.c, and rebased patch to take into account the
fs/ext4/indirect.c reorganization. -- Ted
fs/ext4/balloc.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/ext4.h | 1 +
fs/ext4/extents.c | 37 +------------------------------------
fs/ext4/indirect.c | 28 +---------------------------
4 files changed, 51 insertions(+), 63 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 264f694..f8224ad 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -620,3 +620,51 @@ unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
}
+/**
+ * ext4_inode_to_goal_block - return a hint for block allocation
+ * @inode: inode for block allocation
+ *
+ * Return the ideal location to start allocating blocks for a
+ * newly created inode.
+ */
+ext4_fsblk_t ext4_inode_to_goal_block(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ ext4_group_t block_group;
+ ext4_grpblk_t colour;
+ int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
+ ext4_fsblk_t bg_start;
+ ext4_fsblk_t last_block;
+
+ block_group = ei->i_block_group;
+ if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
+ /*
+ * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
+ * block groups per flexgroup, reserve the first block
+ * group for directories and special files. Regular
+ * files will start at the second block group. This
+ * tends to speed up directory access and improves
+ * fsck times.
+ */
+ block_group &= ~(flex_size-1);
+ if (S_ISREG(inode->i_mode))
+ block_group++;
+ }
+ bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
+ last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
+
+ /*
+ * If we are doing delayed allocation, we don't need take
+ * colour into account.
+ */
+ if (test_opt(inode->i_sb, DELALLOC))
+ return bg_start;
+
+ if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
+ colour = (current->pid % 16) *
+ (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+ else
+ colour = (current->pid % 16) * ((last_block - bg_start) / 16);
+ return bg_start + colour;
+}
+
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ddaf504..49d2cea 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1743,6 +1743,7 @@ extern unsigned ext4_init_block_bitmap(struct super_block *sb,
struct ext4_group_desc *desc);
#define ext4_free_blocks_after_init(sb, group, desc) \
ext4_init_block_bitmap(sb, NULL, group, desc)
+ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
/* dir.c */
extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index eb63c7b..f331e50 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -114,12 +114,6 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
struct ext4_ext_path *path,
ext4_lblk_t block)
{
- struct ext4_inode_info *ei = EXT4_I(inode);
- ext4_fsblk_t bg_start;
- ext4_fsblk_t last_block;
- ext4_grpblk_t colour;
- ext4_group_t block_group;
- int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
int depth;
if (path) {
@@ -161,36 +155,7 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
}
/* OK. use inode's group */
- block_group = ei->i_block_group;
- if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
- /*
- * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
- * block groups per flexgroup, reserve the first block
- * group for directories and special files. Regular
- * files will start at the second block group. This
- * tends to speed up directory access and improves
- * fsck times.
- */
- block_group &= ~(flex_size-1);
- if (S_ISREG(inode->i_mode))
- block_group++;
- }
- bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
- last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
-
- /*
- * If we are doing delayed allocation, we don't need take
- * colour into account.
- */
- if (test_opt(inode->i_sb, DELALLOC))
- return bg_start;
-
- if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
- colour = (current->pid % 16) *
- (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
- else
- colour = (current->pid % 16) * ((last_block - bg_start) / 16);
- return bg_start + colour + block;
+ return ext4_inode_to_goal_block(inode);
}
/*
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index c3e85a8..6c27111 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -207,11 +207,6 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
struct ext4_inode_info *ei = EXT4_I(inode);
__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
__le32 *p;
- ext4_fsblk_t bg_start;
- ext4_fsblk_t last_block;
- ext4_grpblk_t colour;
- ext4_group_t block_group;
- int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
/* Try to find previous block */
for (p = ind->p - 1; p >= start; p--) {
@@ -227,28 +222,7 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
* It is going to be referred to from the inode itself? OK, just put it
* into the same cylinder group then.
*/
- block_group = ei->i_block_group;
- if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
- block_group &= ~(flex_size-1);
- if (S_ISREG(inode->i_mode))
- block_group++;
- }
- bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
- last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
-
- /*
- * If we are doing delayed allocation, we don't need take
- * colour into account.
- */
- if (test_opt(inode->i_sb, DELALLOC))
- return bg_start;
-
- if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
- colour = (current->pid % 16) *
- (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
- else
- colour = (current->pid % 16) * ((last_block - bg_start) / 16);
- return bg_start + colour;
+ return ext4_inode_to_goal_block(inode);
}
/**
--
1.7.4.1.22.gec8e1.dirty
--
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