From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wendy Cheng Date: Thu, 09 Aug 2007 09:51:01 -0400 Subject: [Cluster-devel] [PATCH 4 of 5] Bz #248176: GFS2: invalid metadata block - REVISED In-Reply-To: <46BB1AC4.9030509@redhat.com> References: <1186609929.25269.46.camel@technetium.msp.redhat.com> <46BB1AC4.9030509@redhat.com> Message-ID: <46BB1BC5.1020701@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sorry ... hand and head do not coordinate well. Somehow I use "spin lock" but it is actually a semaphore.... Wendy > 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 > >