From 21c056f51d7323de11c0a6abe94129ed64bc6891 Mon Sep 17 00:00:00 2001
From: Yorhel <git@yorhel.nl>
Date: Mon, 27 Aug 2012 21:10:07 +0200
Subject: [PATCH] Use uint64_t instead of dev_t as well + added comment
 explaining this

---
 src/dir_scan.c |  8 ++++----
 src/global.h   | 20 +++++++++++---------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/dir_scan.c b/src/dir_scan.c
index 4b07ed5..a0efcb3 100644
--- a/src/dir_scan.c
+++ b/src/dir_scan.c
@@ -43,14 +43,14 @@
 
 int dir_scan_smfs; /* Stay on the same filesystem */
 
-static dev_t curdev;   /* current device we're scanning on */
+static uint64_t curdev;   /* current device we're scanning on */
 
 
 /* Populates the struct dir item with information from the stat struct. Sets
  * everything necessary for output_dir.item() except FF_ERR and FF_EXL. */
 static void stat_to_dir(struct dir *d, struct stat *fs) {
   d->ino = (uint64_t)fs->st_ino;
-  d->dev = fs->st_dev;
+  d->dev = (uint64_t)fs->st_dev;
 
   if(S_ISREG(fs->st_mode))
     d->flags |= FF_FILE;
@@ -60,7 +60,7 @@ static void stat_to_dir(struct dir *d, struct stat *fs) {
   if(!S_ISDIR(fs->st_mode) && fs->st_nlink > 1)
     d->flags |= FF_HLNKC;
 
-  if(dir_scan_smfs && curdev != fs->st_dev)
+  if(dir_scan_smfs && curdev != d->dev)
     d->flags |= FF_OTHFS;
 
   if(!(d->flags & (FF_OTHFS|FF_EXL))) {
@@ -254,7 +254,7 @@ int dir_scan_process() {
   }
 
   if(!dir_fatalerr) {
-    curdev = fs.st_dev;
+    curdev = (uint64_t)fs.st_dev;
     d = dir_createstruct(dir_curpath);
     if(fail)
       d->flags |= FF_ERR;
diff --git a/src/global.h b/src/global.h
index 7737204..edebb83 100644
--- a/src/global.h
+++ b/src/global.h
@@ -55,25 +55,27 @@
 #define ST_HELP   3
 
 
-/* structure representing a file or directory
- * XXX: probably a good idea to get rid of the custom _t types and use
- *      fixed-size integers instead, which are much more predictable */
+/* structure representing a file or directory */
 struct dir {
   struct dir *parent, *next, *prev, *sub, *hlnk;
   int64_t size, asize;
-  uint64_t ino;
+  uint64_t ino, dev;
   int items;
-  dev_t dev;
   unsigned char flags;
   char name[3]; /* must be large enough to hold ".." */
 }; 
 /* sizeof(total dir) = SDIRSIZE + strlen(name) = sizeof(struct dir) - 3 + strlen(name) + 1 */
 #define SDIRSIZE (sizeof(struct dir)-2)
 
-/* Ideally, the name array should be as large as the padding added to the end of
- * the struct, but I can't figure out a portable way to calculate this. We can
- * be sure that it's at least 3 bytes, though, as the struct is aligned to at
- * least 4 bytes and the flags field is a single byte. */
+/* A note on the ino and dev fields above: ino is usually represented as ino_t,
+ * which POSIX specifies to be an unsigned integer.  dev is usually represented
+ * as dev_t, which may be either a signed or unsigned integer, and in practice
+ * both are used. dev represents an index / identifier of a device or
+ * filesystem, and I'm unsure whether a negative value has any meaning in that
+ * context. Hence my choice of using an unsigned integer. Negative values, if
+ * we encounter them, will just get typecasted into a positive value. No
+ * information is lost in this conversion, and the semantics remain the same.
+ */
 
 
 /* program state */