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: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Steven Whitehouse
2011-08-02 13:13:20 +01:00
bovenliggende 75549186ed
commit 1d4ec642d9

Bestand weergeven

@@ -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) {
gfs2_trans_add_bh(ip->i_gl, bh, 1);
gfs2_dinode_out(ip, bh->b_data);
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)