netfs: Update tracepoints in a number of ways

Make a number of updates to the netfs tracepoints:

 (1) Remove a duplicate trace from netfs_unbuffered_write_iter_locked().

 (2) Move the trace in netfs_wake_rreq_flag() to after the flag is cleared
     so that the change appears in the trace.

 (3) Differentiate the use of netfs_rreq_trace_wait/woke_queue symbols.

 (4) Don't do so many trace emissions in the wait functions as some of them
     are redundant.

 (5) In netfs_collect_read_results(), differentiate a subreq that's being
     abandoned vs one that has been consumed in a regular way.

 (6) Add a tracepoint to indicate the call to ->ki_complete().

 (7) Don't double-increment the subreq_counter when retrying a write.

 (8) Move the netfs_sreq_trace_io_progress tracepoint within cifs code to
     just MID_RESPONSE_RECEIVED and add different tracepoints for other MID
     states and note check failure.

Signed-off-by: David Howells <dhowells@redhat.com>
Co-developed-by: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Link: https://lore.kernel.org/20250701163852.2171681-14-dhowells@redhat.com
cc: Steve French <sfrench@samba.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

6 files changed, 19 insertions, 15 deletions

diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c
index dcf2b096cc4e..a16660ab7f83 100644
--- a/fs/netfs/direct_write.c
+++ b/fs/netfs/direct_write.c
@@ -91,7 +91,6 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *
 	}
 
 	if (!async) {
-		trace_netfs_rreq(wreq, netfs_rreq_trace_wait_ip);
 		ret = netfs_wait_for_write(wreq);
 		if (ret > 0)
 			iocb->ki_pos += ret;
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index f9bb9464a147..d4f16fefd965 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -273,9 +273,9 @@ static inline void netfs_wake_rreq_flag(struct netfs_io_request *rreq,
 					enum netfs_rreq_trace trace)
 {
 	if (test_bit(rreq_flag, &rreq->flags)) {
-		trace_netfs_rreq(rreq, trace);
 		clear_bit_unlock(rreq_flag, &rreq->flags);
 		smp_mb__after_atomic(); /* Set flag before task state */
+		trace_netfs_rreq(rreq, trace);
 		wake_up(&rreq->waitq);
 	}
 }
diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
index 127a269938bb..20748bcfbf59 100644
--- a/fs/netfs/misc.c
+++ b/fs/netfs/misc.c
@@ -359,7 +359,7 @@ void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,
 		if (!netfs_check_subreq_in_progress(subreq))
 			continue;
 
-		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue);
+		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_quiesce);
 		for (;;) {
 			prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
 
@@ -368,10 +368,10 @@ void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,
 
 			trace_netfs_sreq(subreq, netfs_sreq_trace_wait_for);
 			schedule();
-			trace_netfs_rreq(rreq, netfs_rreq_trace_woke_queue);
 		}
 	}
 
+	trace_netfs_rreq(rreq, netfs_rreq_trace_waited_quiesce);
 	finish_wait(&rreq->waitq, &myself);
 }
 
@@ -437,7 +437,6 @@ static ssize_t netfs_wait_for_in_progress(struct netfs_io_request *rreq,
 	ssize_t ret;
 
 	for (;;) {
-		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue);
 		prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
 
 		if (!test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags)) {
@@ -457,11 +456,12 @@ static ssize_t netfs_wait_for_in_progress(struct netfs_io_request *rreq,
 		if (!netfs_check_rreq_in_progress(rreq))
 			break;
 
+		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip);
 		schedule();
-		trace_netfs_rreq(rreq, netfs_rreq_trace_woke_queue);
 	}
 
 all_collected:
+	trace_netfs_rreq(rreq, netfs_rreq_trace_waited_ip);
 	finish_wait(&rreq->waitq, &myself);
 
 	ret = rreq->error;
@@ -504,10 +504,8 @@ static void netfs_wait_for_pause(struct netfs_io_request *rreq,
 {
 	DEFINE_WAIT(myself);
 
-	trace_netfs_rreq(rreq, netfs_rreq_trace_wait_pause);
-
 	for (;;) {
-		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue);
+		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_pause);
 		prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
 
 		if (!test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags)) {
@@ -530,10 +528,10 @@ static void netfs_wait_for_pause(struct netfs_io_request *rreq,
 			break;
 
 		schedule();
-		trace_netfs_rreq(rreq, netfs_rreq_trace_woke_queue);
 	}
 
 all_collected:
+	trace_netfs_rreq(rreq, netfs_rreq_trace_waited_pause);
 	finish_wait(&rreq->waitq, &myself);
 }
 
diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c
index cceed9d629c6..3e804da1e1eb 100644
--- a/fs/netfs/read_collect.c
+++ b/fs/netfs/read_collect.c
@@ -293,7 +293,9 @@ reassess:
 		spin_lock(&rreq->lock);
 
 		remove = front;
-		trace_netfs_sreq(front, netfs_sreq_trace_discard);
+		trace_netfs_sreq(front,
+				 notes & ABANDON_SREQ ?
+				 netfs_sreq_trace_abandoned : netfs_sreq_trace_consumed);
 		list_del_init(&front->rreq_link);
 		front = list_first_entry_or_null(&stream->subrequests,
 						 struct netfs_io_subrequest, rreq_link);
@@ -353,9 +355,11 @@ static void netfs_rreq_assess_dio(struct netfs_io_request *rreq)
 
 	if (rreq->iocb) {
 		rreq->iocb->ki_pos += rreq->transferred;
-		if (rreq->iocb->ki_complete)
+		if (rreq->iocb->ki_complete) {
+			trace_netfs_rreq(rreq, netfs_rreq_trace_ki_complete);
 			rreq->iocb->ki_complete(
 				rreq->iocb, rreq->error ? rreq->error : rreq->transferred);
+		}
 	}
 	if (rreq->netfs_ops->done)
 		rreq->netfs_ops->done(rreq);
@@ -379,9 +383,11 @@ static void netfs_rreq_assess_single(struct netfs_io_request *rreq)
 
 	if (rreq->iocb) {
 		rreq->iocb->ki_pos += rreq->transferred;
-		if (rreq->iocb->ki_complete)
+		if (rreq->iocb->ki_complete) {
+			trace_netfs_rreq(rreq, netfs_rreq_trace_ki_complete);
 			rreq->iocb->ki_complete(
 				rreq->iocb, rreq->error ? rreq->error : rreq->transferred);
+		}
 	}
 	if (rreq->netfs_ops->done)
 		rreq->netfs_ops->done(rreq);
diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c
index 33a93258f36e..0f3a36852a4d 100644
--- a/fs/netfs/write_collect.c
+++ b/fs/netfs/write_collect.c
@@ -421,9 +421,11 @@ bool netfs_write_collection(struct netfs_io_request *wreq)
 	if (wreq->iocb) {
 		size_t written = min(wreq->transferred, wreq->len);
 		wreq->iocb->ki_pos += written;
-		if (wreq->iocb->ki_complete)
+		if (wreq->iocb->ki_complete) {
+			trace_netfs_rreq(wreq, netfs_rreq_trace_ki_complete);
 			wreq->iocb->ki_complete(
 				wreq->iocb, wreq->error ? wreq->error : written);
+		}
 		wreq->iocb = VFS_PTR_POISON;
 	}
 
diff --git a/fs/netfs/write_retry.c b/fs/netfs/write_retry.c
index 7158657061e9..fc9c3e0d34d8 100644
--- a/fs/netfs/write_retry.c
+++ b/fs/netfs/write_retry.c
@@ -146,7 +146,6 @@ static void netfs_retry_write_stream(struct netfs_io_request *wreq,
 			subreq = netfs_alloc_subrequest(wreq);
 			subreq->source		= to->source;
 			subreq->start		= start;
-			subreq->debug_index	= atomic_inc_return(&wreq->subreq_counter);
 			subreq->stream_nr	= to->stream_nr;
 			subreq->retry_count	= 1;