fs: logfs: remove unnecesary check

[mirror_ubuntu-zesty-kernel.git] / fs / logfs / dev_bdev.c

diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index a8329cc47decd627ca26cf608e6f15276697a4f6..9bfa0151d7c9048610becc95c2e02508fe2e6f25 100644 (file)
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -19,16 +19,10 @@ static int sync_request(struct page *page, struct block_device *bdev, int op)
        struct bio bio;
        struct bio_vec bio_vec;
 
-       bio_init(&bio);
-       bio.bi_max_vecs = 1;
-       bio.bi_io_vec = &bio_vec;
-       bio_vec.bv_page = page;
-       bio_vec.bv_len = PAGE_SIZE;
-       bio_vec.bv_offset = 0;
-       bio.bi_vcnt = 1;
+       bio_init(&bio, &bio_vec, 1);
        bio.bi_bdev = bdev;
+       bio_add_page(&bio, page, PAGE_SIZE, 0);
        bio.bi_iter.bi_sector = page->index * (PAGE_SIZE >> 9);
-       bio.bi_iter.bi_size = PAGE_SIZE;
        bio_set_op_attrs(&bio, op, 0);
 
        return submit_bio_wait(&bio);
@@ -77,56 +71,45 @@ 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;
 }
 
@@ -160,7 +143,6 @@ static void erase_end_io(struct bio *bio)
        struct logfs_super *super = logfs_super(sb); 
 
        BUG_ON(bio->bi_error); /* FIXME: Retry io or write elsewhere */ 
-       BUG_ON(bio->bi_vcnt == 0); 
        bio_put(bio); 
        if (atomic_dec_and_test(&super->s_pending_writes))
                wake_up(&wq); 
@@ -170,49 +152,35 @@ 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;
                        bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+               }
+               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(bio);
-
-                       ofs += i * PAGE_SIZE;
-                       index += i;
-                       nr_pages -= i;
-                       i = 0;
-
-                       bio = bio_alloc(GFP_NOFS, max_pages);
-                       BUG_ON(!bio);
                }
-               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;
-       bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-       atomic_inc(&super->s_pending_writes);
-       submit_bio(bio);
+       if (bio) {
+               atomic_inc(&super->s_pending_writes);
+               submit_bio(bio);
+       }
        return 0;
 }