Commit 856d865c authored by Ojaswin Mujoo's avatar Ojaswin Mujoo Committed by Theodore Ts'o
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ext4: Abstract out logic to search average fragment list 



Make the logic of searching average fragment list of a given order reusable
by abstracting it out to a differnet function. This will also avoid
code duplication in upcoming patches.

No functional changes.

Signed-off-by: default avatarOjaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/028c11d95b17ce0285f45456709a0ca922df1b83.1685449706.git.ojaswin@linux.ibm.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 4f3d1e45

fs/ext4/mballoc.c

+33 −18
Original line number Diff line number Diff line
@@ -904,6 +904,37 @@ static void ext4_mb_choose_next_group_cr0(struct ext4_allocation_context *ac, 
	}

}



/*

 * Find a suitable group of given order from the average fragments list.

 */

static struct ext4_group_info *

ext4_mb_find_good_group_avg_frag_lists(struct ext4_allocation_context *ac, int order)

{

	struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);

	struct list_head *frag_list = &sbi->s_mb_avg_fragment_size[order];

	rwlock_t *frag_list_lock = &sbi->s_mb_avg_fragment_size_locks[order];

	struct ext4_group_info *grp = NULL, *iter;

	enum criteria cr = ac->ac_criteria;



	if (list_empty(frag_list))

		return NULL;

	read_lock(frag_list_lock);

	if (list_empty(frag_list)) {

		read_unlock(frag_list_lock);

		return NULL;

	}

	list_for_each_entry(iter, frag_list, bb_avg_fragment_size_node) {

		if (sbi->s_mb_stats)

			atomic64_inc(&sbi->s_bal_cX_groups_considered[cr]);

		if (likely(ext4_mb_good_group(ac, iter->bb_group, cr))) {

			grp = iter;

			break;

		}

	}

	read_unlock(frag_list_lock);

	return grp;

}



/*

 * Choose next group by traversing average fragment size list of suitable

 * order. Updates *new_cr if cr level needs an update.
@@ -912,7 +943,7 @@ static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac, 
		enum criteria *new_cr, ext4_group_t *group, ext4_group_t ngroups)

{

	struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);

	struct ext4_group_info *grp = NULL, *iter;

	struct ext4_group_info *grp = NULL;

	int i;



	if (unlikely(ac->ac_flags & EXT4_MB_CR1_OPTIMIZED)) {
@@ -922,23 +953,7 @@ static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac, 


	for (i = mb_avg_fragment_size_order(ac->ac_sb, ac->ac_g_ex.fe_len);

	     i < MB_NUM_ORDERS(ac->ac_sb); i++) {

		if (list_empty(&sbi->s_mb_avg_fragment_size[i]))

			continue;

		read_lock(&sbi->s_mb_avg_fragment_size_locks[i]);

		if (list_empty(&sbi->s_mb_avg_fragment_size[i])) {

			read_unlock(&sbi->s_mb_avg_fragment_size_locks[i]);

			continue;

		}

		list_for_each_entry(iter, &sbi->s_mb_avg_fragment_size[i],

				    bb_avg_fragment_size_node) {

			if (sbi->s_mb_stats)

				atomic64_inc(&sbi->s_bal_cX_groups_considered[CR1]);

			if (likely(ext4_mb_good_group(ac, iter->bb_group, CR1))) {

				grp = iter;

				break;

			}

		}

		read_unlock(&sbi->s_mb_avg_fragment_size_locks[i]);

		grp = ext4_mb_find_good_group_avg_frag_lists(ac, i);

		if (grp)

			break;

	}