From adde997a38c007e9456ccf0cb83bb92c1a54a969 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Wed, 8 Oct 2025 12:42:40 +0200
Subject: [PATCH] Extend block time information to 64 bits

Prevent potential timestamp overflow for the last write operation, which
could occur around 2106. The content format remains unchanged, as values are
expected to stay within the 32-bit range until then.
---
 cmdline/elem.h  |  4 ++--
 cmdline/state.c | 19 ++++++++++++-------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/cmdline/elem.h b/cmdline/elem.h
index e8eb3100..7e0d6a4e 100644
--- a/cmdline/elem.h
+++ b/cmdline/elem.h
@@ -485,7 +485,7 @@ struct snapraid_parity {
 /**
  * Info.
  */
-typedef uint32_t snapraid_info;
+typedef uint64_t snapraid_info;
 
 /**
  * Allocate a content.
@@ -1122,7 +1122,7 @@ void map_free(struct snapraid_map* map);
  *
  * These bits reduce the granularity of the time in the memory representation.
  */
-#define INFO_MASK 0x7
+#define INFO_MASK ((snapraid_info)0x7)
 
 /**
  * Make an info.
diff --git a/cmdline/state.c b/cmdline/state.c
index 705a4094..7ad1d09d 100644
--- a/cmdline/state.c
+++ b/cmdline/state.c
@@ -2184,9 +2184,9 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 			/* "inf" command */
 			snapraid_info info;
 			uint32_t v_pos;
-			uint32_t v_oldest;
+			uint64_t v_oldest;
 
-			ret = sgetb32(f, &v_oldest);
+			ret = sgetb64(f, &v_oldest);
 			if (ret < 0) {
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
@@ -2199,7 +2199,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				int bad;
 				int rehash;
 				int justsynced;
-				uint32_t t;
+				uint64_t t64;
 				uint32_t flag;
 				uint32_t v_count;
 
@@ -2230,7 +2230,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 				/* if there is an info */
 				if ((flag & 1) != 0) {
 					/* read the time */
-					ret = sgetb32(f, &t);
+					ret = sgetb64(f, &t64);
 					if (ret < 0) {
 						/* LCOV_EXCL_START */
 						decoding_error(path, f);
@@ -2251,7 +2251,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 						/* LCOV_EXCL_STOP */
 					}
 
-					info = info_make(t + v_oldest, bad, rehash, justsynced);
+					info = info_make(t64 + v_oldest, bad, rehash, justsynced);
 				} else {
 					info = 0;
 				}
@@ -3041,6 +3041,7 @@ static void* state_write_thread(void* arg)
 	int info_has_rehash = context->info_has_rehash;
 	STREAM* f = context->f;
 	uint32_t crc;
+	uint64_t t64;
 	unsigned count_file;
 	unsigned count_hardlink;
 	unsigned count_symlink;
@@ -3400,7 +3401,9 @@ static void* state_write_thread(void* arg)
 
 	/* write the info for each block */
 	sputc('i', f);
-	sputb32(info_oldest, f);
+	/* ensure to write a 64 bit time */
+	t64 = info_oldest;
+	sputb64(t64, f);
 	begin = 0;
 	while (begin < blockmax) {
 		snapraid_info info;
@@ -3444,7 +3447,9 @@ static void* state_write_thread(void* arg)
 			else
 				t -= info_oldest;
 
-			sputb32(t, f);
+			/* ensure to write a 64 bit time */
+			t64 = t;
+			sputb64(t64, f);
 		} else {
 			/* write a special 0 flag to mark missing info */
 			sputb32(0, f);