[PATCH] f2fs: remove the ugly pointer conversion

From: Jaegeuk Kim
Date: Mon Feb 03 2014 - 01:06:06 EST


This patch modifies the use of bi_private to remove pointer chasing for sbi.
Previously, we had a bi_private structure, but it needs memory allocation.
So this patch uses bi_private by the sbi pointer and adds a completion pointer
into the sbi.
This can achieve no memory allocation and nice use of the bi_private.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
---
fs/f2fs/data.c | 11 +++++++----
fs/f2fs/f2fs.h | 1 +
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 20c3c64..d175ae3 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -45,7 +45,7 @@ static void f2fs_read_end_io(struct bio *bio, int err)

static void f2fs_write_end_io(struct bio *bio, int err)
{
- struct f2fs_sb_info *sbi = F2FS_SB(bio->bi_io_vec->bv_page->mapping->host->i_sb);
+ struct f2fs_sb_info *sbi = bio->bi_private;
struct bio_vec *bvec;
int i;

@@ -61,8 +61,10 @@ static void f2fs_write_end_io(struct bio *bio, int err)
dec_page_count(sbi, F2FS_WRITEBACK);
}

- if (bio->bi_private)
- complete(bio->bi_private);
+ if (sbi->wait_io) {
+ complete(sbi->wait_io);
+ sbi->wait_io = NULL;
+ }

if (!get_pages(sbi, F2FS_WRITEBACK) &&
!list_empty(&sbi->cp_wait.task_list))
@@ -85,6 +87,7 @@ static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
bio->bi_bdev = sbi->sb->s_bdev;
bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
+ bio->bi_private = sbi;

return bio;
}
@@ -112,7 +115,7 @@ static void __submit_merged_bio(struct f2fs_bio_info *io)
*/
if (fio->type == META_FLUSH) {
DECLARE_COMPLETION_ONSTACK(wait);
- io->bio->bi_private = &wait;
+ io->sbi->wait_io = &wait;
submit_bio(rw, io->bio);
wait_for_completion(&wait);
} else {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 55288d2..aeff132 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -398,6 +398,7 @@ struct f2fs_sb_info {
/* for bio operations */
struct f2fs_bio_info read_io; /* for read bios */
struct f2fs_bio_info write_io[NR_PAGE_TYPE]; /* for write bios */
+ struct completion *wait_io; /* for completion bios */

/* for checkpoint */
struct f2fs_checkpoint *ckpt; /* raw checkpoint pointer */
--
1.8.4.474.g128a96c

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