Commit f86186b4 authored by Eric Sandeen's avatar Eric Sandeen Committed by Theodore Ts'o
Browse files

ext4: refactor duplicated block placement code 



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: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent dae1e52c

fs/ext4/balloc.c

+48 −0
Original line number Diff line number Diff line
@@ -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;

}

fs/ext4/ext4.h

+1 −0
Original line number Diff line number Diff line
@@ -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 *,

fs/ext4/extents.c

+1 −36
Original line number Diff line number Diff line
@@ -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);

}



/*

fs/ext4/indirect.c

+1 −27
Original line number Diff line number Diff line
@@ -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);

}



/**

CRA Git | Maintained and supported by SUSTech CRA and CCSE