From: Tejun Heo Subject: [PATCH 2/2] ext4: implement cgroup writeback support Date: Fri, 12 Jun 2015 17:02:23 -0500 Message-ID: <1434146543-26358-3-git-send-email-tj@kernel.org> References: <1434146543-26358-1-git-send-email-tj@kernel.org> Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, lizefan@huawei.com, cgroups@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, Tejun Heo To: axboe@kernel.dk Return-path: In-Reply-To: <1434146543-26358-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org For ordered and writeback data modes, all data IOs go through ext4_io_submit. This patch adds cgroup writeback support by invoking wbc_init_bio() from io_submit_init_bio() and wbc_account_io() in io_submit_add_bh(). Journal data which is written by jbd2 worker is left alone by this patch and will always be written out from the root cgroup. ext4_fill_super() is updated to set MS_CGROUPWB when data mode is either ordered or writeback. In journaled data mode, most IOs become synchronous through the journal and enabling cgroup writeback support doesn't make much sense or difference. Journaled data mode is left alone. Lightly tested with sequential data write workload. Behaves as expected. Signed-off-by: Tejun Heo Cc: "Theodore Ts'o" Cc: Andreas Dilger Cc: linux-ext4@vger.kernel.org --- fs/ext4/page-io.c | 2 ++ fs/ext4/super.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 3f80cb2..c56ba7b 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -383,6 +383,7 @@ static int io_submit_init_bio(struct ext4_io_submit *io, bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); if (!bio) return -ENOMEM; + wbc_init_bio(io->io_wbc, bio); bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; bio->bi_end_io = ext4_end_bio; @@ -411,6 +412,7 @@ static int io_submit_add_bh(struct ext4_io_submit *io, ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); if (ret != bh->b_size) goto submit_and_retry; + wbc_account_io(io->io_wbc, page, bh->b_size); io->io_next_block++; return 0; } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 56b8bb7..a9a3de3 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3623,6 +3623,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } if (test_opt(sb, DELALLOC)) clear_opt(sb, DELALLOC); + } else { + sb->s_flags |= MS_CGROUPWB; } sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | -- 2.4.2