[PATCH 24/27] fs: logfs: use bio_add_page() in do_erase()

From: Ming Lei
Date: Tue Apr 05 2016 - 08:10:09 EST


Also code gets simplified a bit.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
fs/logfs/dev_bdev.c | 45 ++++++++++++++++++---------------------------
1 file changed, 18 insertions(+), 27 deletions(-)

diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index 1df84e0..db04231 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -154,47 +154,38 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
size_t nr_pages)
{
struct logfs_super *super = logfs_super(sb);
- struct bio *bio;
+ struct bio *bio = NULL;
unsigned int max_pages;
- int i;
+ int i, ret;

max_pages = min_t(size_t, nr_pages, BIO_MAX_PAGES);

- bio = bio_alloc(GFP_NOFS, max_pages);
- BUG_ON(!bio);
-
for (i = 0; i < nr_pages; i++) {
- if (i >= max_pages) {
- /* Block layer cannot split bios :( */
- bio->bi_vcnt = i;
- bio->bi_iter.bi_size = i * PAGE_SIZE;
+ if (!bio) {
+ bio = bio_alloc(GFP_NOFS, max_pages);
+ BUG_ON(!bio);
+
bio->bi_bdev = super->s_bdev;
bio->bi_iter.bi_sector = ofs >> 9;
bio->bi_private = sb;
bio->bi_end_io = erase_end_io;
+ }
+
+ ret = bio_add_page(bio, super->s_erase_page, PAGE_SIZE, 0);
+ if (!ret) {
+ /* Block layer cannot split bios :( */
+ ofs += bio->bi_iter.bi_size;
atomic_inc(&super->s_pending_writes);
submit_bio(WRITE, bio);

- ofs += i * PAGE_SIZE;
- index += i;
- nr_pages -= i;
- i = 0;
-
- bio = bio_alloc(GFP_NOFS, max_pages);
- BUG_ON(!bio);
+ bio = NULL;
}
- bio->bi_io_vec[i].bv_page = super->s_erase_page;
- bio->bi_io_vec[i].bv_len = PAGE_SIZE;
- bio->bi_io_vec[i].bv_offset = 0;
}
- bio->bi_vcnt = nr_pages;
- bio->bi_iter.bi_size = nr_pages * PAGE_SIZE;
- bio->bi_bdev = super->s_bdev;
- bio->bi_iter.bi_sector = ofs >> 9;
- bio->bi_private = sb;
- bio->bi_end_io = erase_end_io;
- atomic_inc(&super->s_pending_writes);
- submit_bio(WRITE, bio);
+
+ if (bio) {
+ atomic_inc(&super->s_pending_writes);
+ submit_bio(WRITE, bio);
+ }
return 0;
}

--
1.9.1