[Cluster-devel] [PATCH 1/4] gfs2: add IO submission trace points

[Dave Chinner]

Useful for tracking down where specific IOs are being issued
from.

Signed-off-by: Dave Chinner <dchinner at redhat.com>
---
 fs/gfs2/log.c        |    6 ++++++
 fs/gfs2/lops.c       |    6 ++++++
 fs/gfs2/trace_gfs2.h |   41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 4511b08..bd26dff 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -121,6 +121,7 @@ __acquires(&sdp->sd_log_lock)
 			lock_buffer(bh);
 			if (test_clear_buffer_dirty(bh)) {
 				bh->b_end_io = end_buffer_write_sync;
+				trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 				submit_bh(WRITE_SYNC_PLUG, bh);
 			} else {
 				unlock_buffer(bh);
@@ -610,6 +611,8 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
 		goto skip_barrier;
 	get_bh(bh);
+	trace_gfs2_submit_bh(bh, WRITE_SYNC | (1 << BIO_RW_BARRIER) | (1 <<
+	BIO_RW_META), __func__);
 	submit_bh(WRITE_SYNC | (1 << BIO_RW_BARRIER) | (1 << BIO_RW_META), bh);
 	wait_on_buffer(bh);
 	if (buffer_eopnotsupp(bh)) {
@@ -619,6 +622,8 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 		lock_buffer(bh);
 skip_barrier:
 		get_bh(bh);
+		trace_gfs2_submit_bh(bh, WRITE_SYNC | (1 << BIO_RW_META),
+		__func__);
 		submit_bh(WRITE_SYNC | (1 << BIO_RW_META), bh);
 		wait_on_buffer(bh);
 	}
@@ -670,6 +675,7 @@ static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 		lock_buffer(bh);
 		if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
 			bh->b_end_io = end_buffer_write_sync;
+			trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 			submit_bh(WRITE_SYNC_PLUG, bh);
 		} else {
 			unlock_buffer(bh);
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index de97632..5708edf 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -198,6 +198,7 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
 		}
 
 		gfs2_log_unlock(sdp);
+		trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 		submit_bh(WRITE_SYNC_PLUG, bh);
 		gfs2_log_lock(sdp);
 
@@ -208,6 +209,7 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
 			gfs2_log_unlock(sdp);
 			lock_buffer(bd2->bd_bh);
 			bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
+			trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 			submit_bh(WRITE_SYNC_PLUG, bh);
 			gfs2_log_lock(sdp);
 			if (++n >= num)
@@ -350,6 +352,7 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
 		sdp->sd_log_num_revoke--;
 
 		if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
+			trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 			submit_bh(WRITE_SYNC_PLUG, bh);
 
 			bh = gfs2_log_get_buf(sdp);
@@ -367,6 +370,7 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
 	}
 	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 
+	trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 	submit_bh(WRITE_SYNC_PLUG, bh);
 }
 
@@ -569,6 +573,7 @@ static void gfs2_write_blocks(struct gfs2_sbd *sdp, struct buffer_head *bh,
 	ptr = bh_log_ptr(bh);
 	
 	get_bh(bh);
+	trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
 	submit_bh(WRITE_SYNC_PLUG, bh);
 	gfs2_log_lock(sdp);
 	while(!list_empty(list)) {
@@ -595,6 +600,7 @@ static void gfs2_write_blocks(struct gfs2_sbd *sdp, struct buffer_head *bh,
 		} else {
 			bh1 = gfs2_log_fake_buf(sdp, bd->bd_bh);
 		}
+		trace_gfs2_submit_bh(bh1, WRITE_SYNC_PLUG, __func__);
 		submit_bh(WRITE_SYNC_PLUG, bh1);
 		gfs2_log_lock(sdp);
 		ptr += 2;
diff --git a/fs/gfs2/trace_gfs2.h b/fs/gfs2/trace_gfs2.h
index 148d55c..e9a231d 100644
--- a/fs/gfs2/trace_gfs2.h
+++ b/fs/gfs2/trace_gfs2.h
@@ -397,6 +397,47 @@ TRACE_EVENT(gfs2_block_alloc,
 		  block_state_name(__entry->block_state))
 );
 
+#include <linux/fs.h>
+#include <linux/bio.h>
+
+#define BH_IO_TYPE \
+	{ READ,		"read" }, \
+	{ WRITE,	"write" }, \
+	{ READA,	"readahead" }, \
+	{ SWRITE,	"swrite" }, \
+	{ READ_SYNC,	"read sync" }, \
+	{ READ_META,	"read meta" }, \
+	{ WRITE_SYNC,	"write sync" }, \
+	{ WRITE_SYNC_PLUG, "write sync plug" }, \
+	{ WRITE_META,	"write meta" }, \
+	{ WRITE_BARRIER, "write barrier" }
+
+TRACE_EVENT(gfs2_submit_bh,
+	TP_PROTO(struct buffer_head *bh, int rw, const char * func),
+	TP_ARGS(bh, rw, func),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(unsigned long long, bno)
+		__field(unsigned long long, len)
+		__field(int, rw)
+		__field(const char *, func)
+	),
+	TP_fast_assign(
+		__entry->dev = bh->b_bdev->bd_dev;
+		__entry->bno = bh->b_blocknr;
+		__entry->len = bh->b_size;
+		__entry->rw = rw;
+		__entry->func = func;
+	),
+	TP_printk("dev %d:%d %s bno %llu len %llu caller %s",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __print_symbolic(__entry->rw, BH_IO_TYPE),
+		  __entry->bno,
+		  __entry->len,
+		  __entry->func)
+);
+
+
 #endif /* _TRACE_GFS2_H */
 
 /* This part must be outside protection */
-- 
1.6.5