Bob,
On Wed, 1 May 2019 at 01:03, Bob Peterson <rpete...@redhat.com> wrote:
> This patch adds some instrumentation in gfs2's journal replay that
> indicates when we're about to overwrite a rgrp for which we already
> have a valid buffer_head.
looks okay, but can you explain in the commit message when this
problem will trigger and why that's a problem?
Thanks,
Andreas
> Signed-off-by: Bob Peterson <rpete...@redhat.com>
> ---
> fs/gfs2/lops.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
> index 6af6a3cea967..2e8c6d02e112 100644
> --- a/fs/gfs2/lops.c
> +++ b/fs/gfs2/lops.c
> @@ -564,9 +564,27 @@ static int buf_lo_scan_elements(struct gfs2_jdesc *jd,
> u32 start,
>
> if (gfs2_meta_check(sdp, bh_ip))
> error = -EIO;
> - else
> + else {
> + struct gfs2_meta_header *mh =
> + (struct gfs2_meta_header *)bh_ip->b_data;
> +
> + if (mh->mh_type == cpu_to_be32(GFS2_METATYPE_RG)) {
> + struct gfs2_rgrpd *rgd;
> +
> + rgd = gfs2_blk2rgrpd(sdp, blkno, false);
> + if (rgd && rgd->rd_addr == blkno &&
> + rgd->rd_bits && rgd->rd_bits->bi_bh) {
> + fs_info(sdp, "Replaying 0x%llx but we
> "
> + "already have a bh!\n",
> + (unsigned long long)blkno);
> + fs_info(sdp, "busy:%d, pinned:%d\n",
> +
> buffer_busy(rgd->rd_bits->bi_bh) ? 1 : 0,
> +
> buffer_pinned(rgd->rd_bits->bi_bh));
> + gfs2_dump_glock(NULL, rgd->rd_gl);
> + }
> + }
> mark_buffer_dirty(bh_ip);
> -
> + }
> brelse(bh_log);
> brelse(bh_ip);
>
> --
> 2.20.1
>
