btrfs: don't use btrfs_bio_ctrl for extent buffer writing

The btrfs_bio_ctrl machinery is overkill for writing extent_buffers
as we always operate on PAGE_SIZE chunks (or one smaller one for the
subpage case) that are contiguous and are guaranteed to fit into a
single bio.  Replace it with open coded btrfs_bio_alloc, __bio_add_page
and btrfs_submit_bio calls.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 6284dfd..3d60dde 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -121,9 +121,6 @@ static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
        /* Caller should ensure the bio has at least some range added */
        ASSERT(bbio->bio.bi_iter.bi_size);
 
-       if (!is_data_inode(&bbio->inode->vfs_inode))
-               bbio->bio.bi_opf |= REQ_META;
-
        if (btrfs_op(&bbio->bio) == BTRFS_MAP_READ &&
            bio_ctrl->compress_type != BTRFS_COMPRESS_NONE)
                btrfs_submit_compressed_read(bbio);
@@ -1899,11 +1896,7 @@ static void write_one_subpage_eb(struct extent_buffer *eb,
        struct btrfs_fs_info *fs_info = eb->fs_info;
        struct page *page = eb->pages[0];
        bool no_dirty_ebs = false;
-       struct btrfs_bio_ctrl bio_ctrl = {
-               .wbc = wbc,
-               .opf = REQ_OP_WRITE | wbc_to_write_flags(wbc),
-               .end_io_func = end_bio_subpage_eb_writepage,
-       };
+       struct btrfs_bio *bbio;
 
        prepare_eb_write(eb);
 
@@ -1917,10 +1910,17 @@ static void write_one_subpage_eb(struct extent_buffer *eb,
        if (no_dirty_ebs)
                clear_page_dirty_for_io(page);
 
-       submit_extent_page(&bio_ctrl, eb->start, page, eb->len,
-                          eb->start - page_offset(page));
+       bbio = btrfs_bio_alloc(INLINE_EXTENT_BUFFER_PAGES,
+                              REQ_OP_WRITE | REQ_META | wbc_to_write_flags(wbc),
+                              eb->fs_info, end_bio_subpage_eb_writepage, NULL);
+       bbio->bio.bi_iter.bi_sector = eb->start >> SECTOR_SHIFT;
+       bbio->inode = BTRFS_I(eb->fs_info->btree_inode);
+       bbio->file_offset = eb->start;
+       __bio_add_page(&bbio->bio, page, eb->len, eb->start - page_offset(page));
+       wbc_account_cgroup_owner(wbc, page, eb->len);
        unlock_page(page);
-       submit_one_bio(&bio_ctrl);
+       btrfs_submit_bio(bbio, 0);
+
        /*
         * Submission finished without problem, if no range of the page is
         * dirty anymore, we have submitted a page.  Update nr_written in wbc.
@@ -1932,16 +1932,21 @@ static void write_one_subpage_eb(struct extent_buffer *eb,
 static noinline_for_stack void write_one_eb(struct extent_buffer *eb,
                                            struct writeback_control *wbc)
 {
-       u64 disk_bytenr = eb->start;
+       struct btrfs_bio *bbio;
        int i, num_pages;
-       struct btrfs_bio_ctrl bio_ctrl = {
-               .wbc = wbc,
-               .opf = REQ_OP_WRITE | wbc_to_write_flags(wbc),
-               .end_io_func = end_bio_extent_buffer_writepage,
-       };
 
        prepare_eb_write(eb);
 
+       bbio = btrfs_bio_alloc(INLINE_EXTENT_BUFFER_PAGES,
+                              REQ_OP_WRITE | REQ_META | wbc_to_write_flags(wbc),
+                              eb->fs_info, end_bio_extent_buffer_writepage,
+                              NULL);
+       bbio->bio.bi_iter.bi_sector = eb->start >> SECTOR_SHIFT;
+       bio_set_dev(&bbio->bio, eb->fs_info->fs_devices->latest_dev->bdev);
+       wbc_init_bio(wbc, &bbio->bio);
+       bbio->inode = BTRFS_I(eb->fs_info->btree_inode);
+       bbio->file_offset = eb->start;
+
        num_pages = num_extent_pages(eb);
        for (i = 0; i < num_pages; i++) {
                struct page *p = eb->pages[i];
@@ -1949,12 +1954,12 @@ static noinline_for_stack void write_one_eb(struct extent_buffer *eb,
                lock_page(p);
                clear_page_dirty_for_io(p);
                set_page_writeback(p);
-               submit_extent_page(&bio_ctrl, disk_bytenr, p, PAGE_SIZE, 0);
-               disk_bytenr += PAGE_SIZE;
+               __bio_add_page(&bbio->bio, p, PAGE_SIZE, 0);
+               wbc_account_cgroup_owner(wbc, p, PAGE_SIZE);
                wbc->nr_to_write--;
                unlock_page(p);
        }
-       submit_one_bio(&bio_ctrl);
+       btrfs_submit_bio(bbio, 0);
 }
 
 /*