[PATCH] f2fs: use BIO_MAX_PAGES for bio allocation

[Jaegeuk Kim]

We don't need to allocate bio partially in order to maximize sequential writes.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
 fs/f2fs/checkpoint.c |  2 +-
 fs/f2fs/data.c       |  4 +---
 fs/f2fs/node.c       |  3 +--
 fs/f2fs/segment.c    |  4 ++--
 fs/f2fs/segment.h    | 17 +++--------------
 5 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 654f5d7..157b7fd 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -228,7 +228,7 @@ void ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index)
 	f2fs_put_page(page, 0);
 
 	if (readahead)
-		ra_meta_pages(sbi, index, MAX_BIO_BLOCKS(sbi), META_POR, true);
+		ra_meta_pages(sbi, index, BIO_MAX_PAGES, META_POR, true);
 }
 
 static int f2fs_write_meta_page(struct page *page,
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 77cd9ac..fe8ce5a 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -307,10 +307,8 @@ void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
 		__submit_merged_bio(io);
 alloc_new:
 	if (io->bio == NULL) {
-		int bio_blocks = MAX_BIO_BLOCKS(sbi);
-
 		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
-						bio_blocks, is_read);
+						BIO_MAX_PAGES, is_read);
 		io->fio = *fio;
 	}
 
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 69c42e2..285e2a5 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2101,7 +2101,6 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
 	struct f2fs_node *rn;
 	struct f2fs_summary *sum_entry;
 	block_t addr;
-	int bio_blocks = MAX_BIO_BLOCKS(sbi);
 	int i, idx, last_offset, nrpages;
 
 	/* scan the node segment */
@@ -2110,7 +2109,7 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
 	sum_entry = &sum->entries[0];
 
 	for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
-		nrpages = min(last_offset - i, bio_blocks);
+		nrpages = min(last_offset - i, BIO_MAX_PAGES);
 
 		/* readahead node pages */
 		ra_meta_pages(sbi, addr, nrpages, META_POR, true);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 7a7e3f1..a21a1a3 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2355,10 +2355,10 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
 	unsigned int i, start, end;
 	unsigned int readed, start_blk = 0;
-	int nrpages = MAX_BIO_BLOCKS(sbi) * 8;
 
 	do {
-		readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT, true);
+		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
+							META_SIT, true);
 
 		start = start_blk * sit_i->sents_per_block;
 		end = (start_blk + readed) * sit_i->sents_per_block;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index a6efb5c..d8ff069 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -102,8 +102,6 @@
 	(((sector_t)blk_addr) << F2FS_LOG_SECTORS_PER_BLOCK)
 #define SECTOR_TO_BLOCK(sectors)					\
 	(sectors >> F2FS_LOG_SECTORS_PER_BLOCK)
-#define MAX_BIO_BLOCKS(sbi)						\
-	((int)min((int)max_hw_blocks(sbi), BIO_MAX_PAGES))
 
 /*
  * indicate a block allocation direction: RIGHT and LEFT.
@@ -698,13 +696,6 @@ static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno)
 	return false;
 }
 
-static inline unsigned int max_hw_blocks(struct f2fs_sb_info *sbi)
-{
-	struct block_device *bdev = sbi->sb->s_bdev;
-	struct request_queue *q = bdev_get_queue(bdev);
-	return SECTOR_TO_BLOCK(queue_max_sectors(q));
-}
-
 /*
  * It is very important to gather dirty pages and write at once, so that we can
  * submit a big bio without interfering other data writes.
@@ -722,7 +713,7 @@ static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
 	else if (type == NODE)
 		return 8 * sbi->blocks_per_seg;
 	else if (type == META)
-		return 8 * MAX_BIO_BLOCKS(sbi);
+		return 8 * BIO_MAX_PAGES;
 	else
 		return 0;
 }
@@ -739,11 +730,9 @@ static inline long nr_pages_to_write(struct f2fs_sb_info *sbi, int type,
 		return 0;
 
 	nr_to_write = wbc->nr_to_write;
-
+	desired = BIO_MAX_PAGES;
 	if (type == NODE)
-		desired = 2 * max_hw_blocks(sbi);
-	else
-		desired = MAX_BIO_BLOCKS(sbi);
+		desired <<= 1;
 
 	wbc->nr_to_write = desired;
 	return desired - nr_to_write;
-- 
2.8.3