2016-10-29 08:30:59

by Ming Lei

Subject: [PATCH 11/60] fs: logfs: use bio_add_page() in __bdev_writeseg()

Also this patch simplify the code a bit.

Signed-off-by: Ming Lei <[email protected]>
---
fs/logfs/dev_bdev.c | 51 ++++++++++++++++++++-------------------------------
1 file changed, 20 insertions(+), 31 deletions(-)

diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index 696dcdd65fdd..79be4cb0dfd8 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -72,56 +72,45 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
{
struct logfs_super *super = logfs_super(sb);
struct address_space *mapping = super->s_mapping_inode->i_mapping;
- struct bio *bio;
+ struct bio *bio = NULL;
struct page *page;
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 = writeseg_end_io;
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
- atomic_inc(&super->s_pending_writes);
- submit_bio(bio);
-
- ofs += i * PAGE_SIZE;
- index += i;
- nr_pages -= i;
- i = 0;
-
- bio = bio_alloc(GFP_NOFS, max_pages);
- BUG_ON(!bio);
}
page = find_lock_page(mapping, index + i);
BUG_ON(!page);
- bio->bi_io_vec[i].bv_page = page;
- bio->bi_io_vec[i].bv_len = PAGE_SIZE;
- bio->bi_io_vec[i].bv_offset = 0;
+ ret = bio_add_page(bio, page, PAGE_SIZE, 0);

BUG_ON(PageWriteback(page));
set_page_writeback(page);
unlock_page(page);
+
+ if (!ret) {
+ /* Block layer cannot split bios :( */
+ ofs += bio->bi_iter.bi_size;
+ atomic_inc(&super->s_pending_writes);
+ submit_bio(bio);
+ bio = NULL;
+ }
+ }
+
+ if (bio) {
+ atomic_inc(&super->s_pending_writes);
+ submit_bio(bio);
}
- 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 = writeseg_end_io;
- bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
- atomic_inc(&super->s_pending_writes);
- submit_bio(bio);
return 0;
}

--
2.7.4

2016-10-31 15:29:33

by Christoph Hellwig

Subject: Re: [PATCH 11/60] fs: logfs: use bio_add_page() in __bdev_writeseg()

Looks fine,

Reviewed-by: Christoph Hellwig <[email protected]>