[Cluster-devel] [GFS2 PATCH] GFS2: Made logd daemon take into account log demand

[Bob Peterson]

Hi,

Before this patch, the logd daemon only tried to flush things when
the log blocks pinned exceeded a certain threshold. But when we're
deleting very large files, it may require a huge number of journal
blocks, and that, in turn, may exceed the threshold. This patch
factors that into account.

Signed-off-by: Bob Peterson <rpete...@redhat.com>
---
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index a6a3389..00d8dc2 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -794,6 +794,7 @@ struct gfs2_sbd {
        atomic_t sd_log_thresh1;
        atomic_t sd_log_thresh2;
        atomic_t sd_log_blks_free;
+       atomic_t sd_log_blks_needed;
        wait_queue_head_t sd_log_waitq;
        wait_queue_head_t sd_logd_waitq;
 
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index e58ccef0..4df349c 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -349,6 +349,7 @@ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int 
blks)
        if (gfs2_assert_warn(sdp, blks) ||
            gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
                return -EINVAL;
+       atomic_add(blks, &sdp->sd_log_blks_needed);
 retry:
        free_blocks = atomic_read(&sdp->sd_log_blks_free);
        if (unlikely(free_blocks <= wanted)) {
@@ -370,6 +371,7 @@ retry:
                        wake_up(&sdp->sd_reserving_log_wait);
                goto retry;
        }
+       atomic_sub(blks, &sdp->sd_log_blks_needed);
        trace_gfs2_log_blocks(sdp, -blks);
 
        /*
@@ -891,13 +893,16 @@ void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 
 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
 {
-       return (atomic_read(&sdp->sd_log_pinned) >= 
atomic_read(&sdp->sd_log_thresh1));
+       return (atomic_read(&sdp->sd_log_pinned) +
+               atomic_read(&sdp->sd_log_blks_needed) >=
+               atomic_read(&sdp->sd_log_thresh1));
 }
 
 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
 {
        unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - 
atomic_read(&sdp->sd_log_blks_free);
-       return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
+       return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
+               atomic_read(&sdp->sd_log_thresh2);
 }
 
 /**
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index ff72ac6..86281a9 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -683,6 +683,7 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
                goto fail_jindex;
        }
 
+       atomic_set(&sdp->sd_log_blks_needed, 0);
        if (sdp->sd_args.ar_spectator) {
                sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
                atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);