Use a tracepoint and a counter in gfs2_jdesc to count the number of outstanding reads (in pages) as we read through a journal to aid debugging.
Signed-off-by: Abhi Das <[email protected]> --- fs/gfs2/incore.h | 1 + fs/gfs2/lops.c | 3 +++ fs/gfs2/ops_fstype.c | 1 + fs/gfs2/trace_gfs2.h | 25 +++++++++++++++++++++++++ 4 files changed, 30 insertions(+) diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 31188c0..bb4446d 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -512,6 +512,7 @@ struct gfs2_jdesc { struct gfs2_log_header_host jd_jhead; struct bio *jd_rd_bio; /* bio used for reading this journal */ + atomic_t jd_rd_pg_ct; unsigned int jd_found_blocks; unsigned int jd_found_revokes; unsigned int jd_replayed_blocks; diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c index 518b786..a261398 100644 --- a/fs/gfs2/lops.c +++ b/fs/gfs2/lops.c @@ -250,6 +250,7 @@ static void gfs2_end_log_read(struct bio *bio, int error) ptr = page_address(page); error = gfs2_log_header_in(&lh, ptr); last = page_private(page); + atomic_dec(&jd->jd_rd_pg_ct); if (!test_bit(JDF_JHEAD, &jd->jd_flags)) { mempool_free(page, gfs2_page_pool); @@ -273,6 +274,7 @@ static void gfs2_end_log_read(struct bio *bio, int error) } bio_put(bio); + trace_gfs2_end_log_read(jd); } /** @@ -454,6 +456,7 @@ void gfs2_log_read_extent(struct gfs2_jdesc *jd, u64 dblock, ret = bio_add_page(bio, page, sb->s_blocksize, 0); WARN_ON(ret == 0); } + atomic_inc(&jd->jd_rd_pg_ct); bio->bi_private = jd; } } diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 4a17eaf..ac9855a 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -643,6 +643,7 @@ static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh) break; } jd->jd_rd_bio = NULL; + atomic_set(&jd->jd_rd_pg_ct, 0); spin_lock(&sdp->sd_jindex_spin); jd->jd_jid = sdp->sd_journals++; diff --git a/fs/gfs2/trace_gfs2.h b/fs/gfs2/trace_gfs2.h index d1de2ed..9f0cc8d 100644 --- a/fs/gfs2/trace_gfs2.h +++ b/fs/gfs2/trace_gfs2.h @@ -613,6 +613,31 @@ TRACE_EVENT(gfs2_rs, rs_func_name(__entry->func), (unsigned long)__entry->free) ); +TRACE_EVENT(gfs2_end_log_read, + + TP_PROTO(const struct gfs2_jdesc *jd), + + + TP_ARGS(jd), + + TP_STRUCT__entry( + __field( dev_t, dev ) + __field( unsigned int, jid ) + __field( unsigned int, pages ) + ), + + TP_fast_assign( + __entry->dev = jd->jd_inode->i_sb->s_dev; + __entry->jid = jd->jd_jid; + __entry->pages = atomic_read(&jd->jd_rd_pg_ct); + ), + + TP_printk("%u,%u end_log_read jid:%u outstanding pages:%u", + MAJOR(__entry->dev), MINOR(__entry->dev), + (unsigned int)__entry->jid, + (unsigned int)__entry->pages) +); + #endif /* _TRACE_GFS2_H */ /* This part must be outside protection */ -- 2.4.11
