From 3b64974c255fca9089596b658b92d1ec4ca38e69 Mon Sep 17 00:00:00 2001
From: Graham Percival <gperciva@tarsnap.com>
Date: Fri, 28 Mar 2025 11:23:37 -0700
Subject: [PATCH 1/3] storage_write.c: store connection number in cookie

Also, move "select which connection to use" earlier.

This does not change any program behaviour, but will be useful in the
following commit.
---
 tar/storage/storage_write.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tar/storage/storage_write.c b/tar/storage/storage_write.c
index c6295db0..1b70ccdb 100644
--- a/tar/storage/storage_write.c
+++ b/tar/storage/storage_write.c
@@ -66,6 +66,9 @@ struct write_file_internal {
 	uint64_t machinenum;
 	int done;
 
+	/* Connection we're using. */
+	size_t conn;
+
 	/* Parameters used in write_file. */
 	uint8_t class;
 	uint8_t name[32];
@@ -334,6 +337,9 @@ storage_write_file(STORAGE_W * S, uint8_t * buf, size_t len,
 	if (crypto_file_enc(buf, len, C->filebuf))
 		goto err2;
 
+	/* Select connection to use. */
+	C->conn = S->lastcnum = (S->lastcnum + 1) % S->numconns;
+
 	/* We're issuing a write operation. */
 	S->nbytespending += C->flen;
 
@@ -347,8 +353,7 @@ storage_write_file(STORAGE_W * S, uint8_t * buf, size_t len,
 	}
 
 	/* Ask the netpacket layer to send a request and get a response. */
-	S->lastcnum = (S->lastcnum + 1) % S->numconns;
-	if (netpacket_op(S->NPC[S->lastcnum], callback_write_file_send, C))
+	if (netpacket_op(S->NPC[C->conn], callback_write_file_send, C))
 		goto err0;
 
 	/* Send ourself SIGQUIT or SIGUSR2 if necessary. */

From 9f4fac7eb90a1bf64b757299df5091fb4e40c323 Mon Sep 17 00:00:00 2001
From: Graham Percival <gperciva@tarsnap.com>
Date: Fri, 28 Mar 2025 11:23:38 -0700
Subject: [PATCH 2/3] storage_write.c: track nbytespending per connection

If --aggressive-network is used, this effectively multiplies
MAXPENDING_WRITEBYTES by almost 8.
---
 tar/storage/storage_write.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/tar/storage/storage_write.c b/tar/storage/storage_write.c
index 1b70ccdb..271bde04 100644
--- a/tar/storage/storage_write.c
+++ b/tar/storage/storage_write.c
@@ -40,7 +40,7 @@ struct storage_write_internal {
 	size_t lastcnum;
 
 	/* Number of bytes of pending writes. */
-	size_t nbytespending;
+	size_t nbytespending[AGGRESSIVE_CNUM];
 
 	/* Last time we wrote a checkpoint. */
 	uint64_t lastcheckpoint;
@@ -147,7 +147,8 @@ storage_write_start(uint64_t machinenum, const uint8_t lastseq[32],
 	S->lastcnum = 0;
 
 	/* No pending writes so far. */
-	S->nbytespending = 0;
+	for (i = 0; i < S->numconns; i++)
+		S->nbytespending[i] = 0;
 
 	/* No checkpoint yet. */
 	S->lastcheckpoint = 0;
@@ -341,13 +342,13 @@ storage_write_file(STORAGE_W * S, uint8_t * buf, size_t len,
 	C->conn = S->lastcnum = (S->lastcnum + 1) % S->numconns;
 
 	/* We're issuing a write operation. */
-	S->nbytespending += C->flen;
+	S->nbytespending[C->conn] += C->flen;
 
 	/*
 	 * Make sure the pending operation queue isn't too large before we
 	 * add yet another operation to it.
 	 */
-	while (S->nbytespending > MAXPENDING_WRITEBYTES) {
+	while (S->nbytespending[C->conn] > MAXPENDING_WRITEBYTES) {
 		if (network_select(1))
 			goto err2;
 	}
@@ -419,7 +420,7 @@ callback_write_file_response(void * cookie,
 	switch (packetbuf[0]) {
 	case 0:
 		/* This write operation is no longer pending. */
-		C->S->nbytespending -= C->flen;
+		C->S->nbytespending[C->conn] -= C->flen;
 		break;
 	case 1:
 		warn0("Cannot store file: File already exists");
@@ -467,15 +468,18 @@ callback_write_file_response(void * cookie,
 int
 storage_write_flush(STORAGE_W * S)
 {
+	size_t i;
 
 	/* No-op on NULL. */
 	if (S == NULL)
 		return (0);
 
 	/* Wait until all pending writes have been completed. */
-	while (S->nbytespending > 0) {
-		if (network_select(1))
-			goto err0;
+	for (i = 0; i < S->numconns; i++) {
+		while (S->nbytespending[i] > 0) {
+			if (network_select(1))
+				goto err0;
+		}
 	}
 
 	/* Success! */

From c4ac3bea3f20efa1e980c7e7affc21ca8950d27d Mon Sep 17 00:00:00 2001
From: Graham Percival <gperciva@tarsnap.com>
Date: Fri, 28 Mar 2025 13:47:14 -0700
Subject: [PATCH 3/3] REBASE? sanity check?

---
 tar/storage/storage_write.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tar/storage/storage_write.c b/tar/storage/storage_write.c
index 271bde04..b82778fc 100644
--- a/tar/storage/storage_write.c
+++ b/tar/storage/storage_write.c
@@ -420,6 +420,10 @@ callback_write_file_response(void * cookie,
 	switch (packetbuf[0]) {
 	case 0:
 		/* This write operation is no longer pending. */
+		if (C->S->nbytespending[C->conn] < C->flen) {
+			warn0("Invalid connection number and/or length");
+			goto err1;
+		}
 		C->S->nbytespending[C->conn] -= C->flen;
 		break;
 	case 1: