Commit 1d4ec642 authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

GFS2: Make atime checks more efficient 



We do not need to start a transaction unless the atime
check has proved positive. Also if we are going to flush
the complete ail list anyway, we might as well skip the
writeback for this specific inode's metadata, since that
will be done as part of the ail writeback process in an
order offering potentially more efficient I/O.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 75549186

fs/gfs2/super.c

+8 −8
Original line number Diff line number Diff line
@@ -768,30 +768,30 @@ static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc) 
			goto do_flush;

		unlock_required = 1;

	}

	ret = gfs2_trans_begin(sdp, RES_DINODE, 0);

	if (ret)

		goto do_unlock;

	ret = gfs2_meta_inode_buffer(ip, &bh);

	if (ret == 0) {

		di = (struct gfs2_dinode *)bh->b_data;

		atime.tv_sec = be64_to_cpu(di->di_atime);

		atime.tv_nsec = be32_to_cpu(di->di_atime_nsec);

		if (timespec_compare(&inode->i_atime, &atime) > 0) {

			ret = gfs2_trans_begin(sdp, RES_DINODE, 0);

			if (ret == 0) {

				gfs2_trans_add_bh(ip->i_gl, bh, 1);

				gfs2_dinode_out(ip, bh->b_data);

				gfs2_trans_end(sdp);

			}

		}

		brelse(bh);

	}

	gfs2_trans_end(sdp);

do_unlock:

	if (unlock_required)

		gfs2_glock_dq_uninit(&gh);

do_flush:

	if (wbc->sync_mode == WB_SYNC_ALL)

		gfs2_log_flush(GFS2_SB(inode), ip->i_gl);

	filemap_fdatawrite(metamapping);

	if (bdi->dirty_exceeded)

		gfs2_ail1_flush(sdp, wbc);

	else

		filemap_fdatawrite(metamapping);

	if (!ret && (wbc->sync_mode == WB_SYNC_ALL))

		ret = filemap_fdatawait(metamapping);

	if (ret)

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