Commit d600af23 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: avoid unneeded loop in build_sit_entries 



When building each sit entry in cache, firstly, we will load it from
sit page, and then check all entries in sit journal, if there is one
updated entry in journal, cover cached entry with the journaled one.

Actually, most of check operation is unneeded since we only need
to update cached entries with journaled entries in batch, so
changing the flow as below for more efficient:
1. load all sit entries into cache from sit pages;
2. update sit entries with journal.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 43ced84e

fs/f2fs/segment.c

+32 −16
Original line number Diff line number Diff line
@@ -2262,22 +2262,11 @@ static void build_sit_entries(struct f2fs_sb_info *sbi) 
			struct f2fs_sit_entry sit;

			struct page *page;



			down_read(&curseg->journal_rwsem);

			for (i = 0; i < sits_in_cursum(journal); i++) {

				if (le32_to_cpu(segno_in_journal(journal, i))

								== start) {

					sit = sit_in_journal(journal, i);

					up_read(&curseg->journal_rwsem);

					goto got_it;

				}

			}

			up_read(&curseg->journal_rwsem);



			page = get_current_sit_page(sbi, start);

			sit_blk = (struct f2fs_sit_block *)page_address(page);

			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];

			f2fs_put_page(page, 1);

got_it:



			check_block_count(sbi, start, &sit);

			seg_info_from_raw_sit(se, &sit);
@@ -2289,13 +2278,40 @@ got_it: 
							se->valid_blocks;

			}



			if (sbi->segs_per_sec > 1) {

				struct sec_entry *e = get_sec_entry(sbi, start);

				e->valid_blocks += se->valid_blocks;

			}

			if (sbi->segs_per_sec > 1)

				get_sec_entry(sbi, start)->valid_blocks +=

							se->valid_blocks;

		}

		start_blk += readed;

	} while (start_blk < sit_blk_cnt);



	down_read(&curseg->journal_rwsem);

	for (i = 0; i < sits_in_cursum(journal); i++) {

		struct f2fs_sit_entry sit;

		struct seg_entry *se;

		unsigned int old_valid_blocks;



		start = le32_to_cpu(segno_in_journal(journal, i));

		se = &sit_i->sentries[start];

		sit = sit_in_journal(journal, i);



		old_valid_blocks = se->valid_blocks;



		check_block_count(sbi, start, &sit);

		seg_info_from_raw_sit(se, &sit);



		if (f2fs_discard_en(sbi)) {

			memcpy(se->discard_map, se->cur_valid_map,

						SIT_VBLOCK_MAP_SIZE);

			sbi->discard_blks += old_valid_blocks -

						se->valid_blocks;

		}



		if (sbi->segs_per_sec > 1)

			get_sec_entry(sbi, start)->valid_blocks +=

				se->valid_blocks - old_valid_blocks;

	}

	up_read(&curseg->journal_rwsem);

}



static void init_free_segmap(struct f2fs_sb_info *sbi)

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