From 04c277f9252a8903fdc9a14abc3999345df38f94 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@users.sourceforge.net>
Date: Fri, 13 Jul 2012 20:53:57 +0200
Subject: [PATCH] Automatically convert old content files to the new nanosecond
 format.

---
 elem.h  |  8 +++++++-
 scan.c  | 15 ++++++++++++++-
 state.c |  6 +++++-
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/elem.h b/elem.h
index 1805736c..baba9e06 100644
--- a/elem.h
+++ b/elem.h
@@ -136,6 +136,12 @@ struct snapraid_block {
 #define FILE_IS_DAMAGED 8 /**< If a fix was attempted but it failed. */
 #define FILE_IS_FIXED 16 /**< If a fix was done. */
 
+/**
+ * Value used to mark files without the nanoseconds value.
+ * Note that this value is never reported by stat().
+ */
+#define FILE_MTIME_NSEC_INVALID -1
+
 /**
  * File.
  */
@@ -144,7 +150,7 @@ struct snapraid_file {
 	uint64_t inode; /**< Inode. */
 	data_off_t size; /**< Size of the file. */
 	struct snapraid_block* blockvec; /**< All the blocks of the file. */
-	int mtime_nsec; /**< Modification time nanoseconds. Less than 1000000000. */
+	int mtime_nsec; /**< Modification time nanoseconds. In the range 0 <= x < 1,000,000,000, or FILE_MTIME_NSEC_INVALID. */
 	block_off_t blockmax; /**< Number of blocks. */
 	unsigned flag; /**< FILE_IS_* flags. */
 	char sub[PATH_MAX]; /**< Sub path of the file. Without the disk dir. The disk is implicit. */
diff --git a/scan.c b/scan.c
index c69b9fd5..7582dd37 100644
--- a/scan.c
+++ b/scan.c
@@ -172,10 +172,23 @@ static void scan_file(struct snapraid_scan* scan, struct snapraid_state* state,
 		}
 
 		/* check if the file is not changed */
-		if (file->size == st->st_size && file->mtime_sec == st->st_mtime && file->mtime_nsec == st->st_mtim.tv_nsec) {
+		if (file->size == st->st_size
+			&& file->mtime_sec == st->st_mtime
+			/* always accept the value if it's FILE_MTIME_NSEC_INVALID */
+			/* it happens when upgrading from an old version of SnapRAID */
+			&& (file->mtime_nsec == st->st_mtim.tv_nsec || file->mtime_nsec == FILE_MTIME_NSEC_INVALID)
+		) {
 			/* mark as present */
 			file_flag_set(file, FILE_IS_PRESENT);
 
+			/* update the nano seconds mtime if required */
+			if (file->mtime_nsec == FILE_MTIME_NSEC_INVALID) {
+				file->mtime_nsec = st->st_mtim.tv_nsec;
+
+				/* we have to save the new mtime */
+				state->need_write = 1;
+			}
+
 			if (strcmp(file->sub, sub) != 0) {
 				/* if the path is different, it means a moved file with the same inode */
 				++scan->count_moved;
diff --git a/state.c b/state.c
index 6433f059..d38975bd 100644
--- a/state.c
+++ b/state.c
@@ -887,7 +887,7 @@ void state_read(struct snapraid_state* state)
 			hash = oathash64(hash, v_mtime_sec);
 
 			c = sgetc(f);
-			if (c == '.') { /* the nanosecond field is present only from version 1.13 */
+			if (c == '.') { /* the nanosecond field is present only from version 1.12 */
 				ret = sgetu32(f, &v_mtime_nsec);
 				if (ret < 0) {
 					fprintf(stderr, "Invalid 'file' specification in '%s' at line %u\n", path, line);
@@ -896,7 +896,11 @@ void state_read(struct snapraid_state* state)
 				hash = oathash32(hash, v_mtime_nsec);
 
 				c = sgetc(f);
+			} else {
+				/* use a special value, meaning that we don't have this information */
+				v_mtime_nsec = FILE_MTIME_NSEC_INVALID;
 			}
+			
 			if (c != ' ') {
 				fprintf(stderr, "Invalid 'file' specification in '%s' at line %u\n", path, line);
 				exit(EXIT_FAILURE);