Commit 429aebc0 authored Nov 18, 2019 by David Sterba

btrfs: get bdev directly from fs_devices in submit_extent_page



This is preparatory patch to remove @bdev parameter from
submit_extent_page. It can't be removed completely, because the cgroups
need it for wbc when initializing the bio

wbc_init_bio
  bio_associate_blkg_from_css
    dereference bdev->bi_disk->queue

The bdev pointer is the same as latest_bdev, thus no functional change.
We can retrieve it from fs_devices that's reachable through several
dereferences. The local variable shadows the parameter, but that's only
temporary.

Signed-off-by: David Sterba <dsterba@suse.com>

parent 3e174099

fs/btrfs/extent_io.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -2987,13 +2987,16 @@ static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
		}

		bio = btrfs_bio_alloc(offset);
		bio_set_dev(bio, bdev);
		bio_add_page(bio, page, page_size, pg_offset);
		bio->bi_end_io = end_io_func;
		bio->bi_private = tree;
		bio->bi_write_hint = page->mapping->host->i_write_hint;
		bio->bi_opf = opf;
		if (wbc) {
		struct block_device *bdev;

		bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev;
		bio_set_dev(bio, bdev);
		wbc_init_bio(wbc, bio);
		wbc_account_cgroup_owner(wbc, page, page_size);
		}

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