[Cluster-devel] [PATCH 4 of 5] Bz #248176: GFS2: invalid metadata block - REVISED
Wendy Cheng
wcheng at redhat.com
Thu Aug 9 13:46:44 UTC 2007
Bob Peterson wrote:
> Part of the problem was that inodes were being recycled
> before their buffers were flushed to the journal logs.
>
>
Set aside "after this patch, the problem goes away" thing ...
I haven't checked previous three patches yet so I may not have the
overall picture ... but why adding the journal flush spin lock here
could prevent the new inode to get re-used before its associated buffer
are flushed to the logs ? Could you elaborate more ?
> diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
> index b93ac45..2d7f7ea 100644
> --- a/fs/gfs2/rgrp.c
> +++ b/fs/gfs2/rgrp.c
> @@ -865,12 +865,15 @@ static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked)
> struct inode *inode;
> u32 goal = 0, block;
> u64 no_addr;
> + struct gfs2_sbd *sdp = rgd->rd_sbd;
>
> for(;;) {
> if (goal >= rgd->rd_data)
> break;
> + down_write(&sdp->sd_log_flush_lock);
> block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED,
> GFS2_BLKST_UNLINKED);
> + up_write(&sdp->sd_log_flush_lock);
> if (block == BFITNOENT)
> break;
>
My concern is that GFS2's usage of sd_log_flush_lock has been very
abused lately. The journal logic is gradually becoming difficult to
understand and maintain. With this change, we move a local spin lock
(that belongs to log.c) into another sub-component (rgrp). Intuitively,
this is not right.
-- Wendy
More information about the Cluster-devel
mailing list