Commit 9592ea80 authored by Bob Peterson's avatar Bob Peterson
Browse files

gfs2: instrumentation wrt ail1 stuck 



Before this patch, if the ail1 flush got stuck for some reason, there
were no clues as to why. This patch introduces a check for getting
stuck for more than a minute, and if it happens, it dumps the items
still remaining on the ail1 list.

Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent e04d339b

fs/gfs2/log.c

+40 −0
Original line number Diff line number Diff line
@@ -139,6 +139,40 @@ __acquires(&sdp->sd_ail_lock) 
	return ret;

}



static void dump_ail_list(struct gfs2_sbd *sdp)

{

	struct gfs2_trans *tr;

	struct gfs2_bufdata *bd;

	struct buffer_head *bh;



	fs_err(sdp, "Error: In gfs2_ail1_flush for ten minutes! t=%d\n",

	       current->journal_info ? 1 : 0);



	list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {

		list_for_each_entry_reverse(bd, &tr->tr_ail1_list,

					    bd_ail_st_list) {

			bh = bd->bd_bh;

			fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd,

			       (unsigned long long)bd->bd_blkno, bh);

			if (!bh) {

				fs_err(sdp, "\n");

				continue;

			}

			fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d "

			       "map:%d new:%d ar:%d aw:%d delay:%d "

			       "io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n",

			       (unsigned long long)bh->b_blocknr,

			       buffer_uptodate(bh), buffer_dirty(bh),

			       buffer_locked(bh), buffer_req(bh),

			       buffer_mapped(bh), buffer_new(bh),

			       buffer_async_read(bh), buffer_async_write(bh),

			       buffer_delay(bh), buffer_write_io_error(bh),

			       buffer_unwritten(bh),

			       buffer_defer_completion(bh),

			       buffer_pinned(bh), buffer_escaped(bh));

		}

	}

}



/**

 * gfs2_ail1_flush - start writeback of some ail1 entries
@@ -155,11 +189,16 @@ void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) 
	struct gfs2_trans *tr;

	struct blk_plug plug;

	int ret = 0;

	unsigned long flush_start = jiffies;



	trace_gfs2_ail_flush(sdp, wbc, 1);

	blk_start_plug(&plug);

	spin_lock(&sdp->sd_ail_lock);

restart:

	if (time_after(jiffies, flush_start + (HZ * 600))) {

		dump_ail_list(sdp);

		goto out;

	}

	list_for_each_entry_reverse(tr, head, tr_list) {

		if (wbc->nr_to_write <= 0)

			break;
@@ -170,6 +209,7 @@ restart: 
			break;

		}

	}

out:

	spin_unlock(&sdp->sd_ail_lock);

	blk_finish_plug(&plug);

	if (ret) {

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