From 5d8f17dcd131099423bdb1c14d15a3ebf9e07668 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Sun, 16 Feb 2014 21:05:25 +0100
Subject: [PATCH] Keeps the default value of -p and -o.

---
 HISTORY      |  4 +++-
 TODO         |  3 ---
 scrub.c      | 30 ++++++++++++++++++++++--------
 snapraid.1   |  3 +--
 snapraid.d   |  3 +--
 snapraid.txt |  3 +--
 6 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/HISTORY b/HISTORY
index 9f9d9806..7ece9282 100644
--- a/HISTORY
+++ b/HISTORY
@@ -19,8 +19,10 @@ SnapRAID HISTORY
  * In "fix", if a previous fixing attempt was made resulting in a
    .unrecoverable file, uses this file as starting point for the
    new attempt.
- * In the log file name allow the use of the '>>', %D, %T modifiers
+ * In the log file name allows the use of the '>>', %D, %T modifiers
    to select append mode, and to insert the date and time in the name.
+ * The options  -p, --percentage and -o, --older-than now keep their
+   default value even if the other one is specified.
  * New source code organization. The RAID engine is now
    an external component usable also in other projects.
 
diff --git a/TODO b/TODO
index d3d78077..ade02890 100644
--- a/TODO
+++ b/TODO
@@ -5,9 +5,6 @@ This is the list of TODO items for SnapRAID.
 
 - Next
 
-* Don't disable default 10d/12% if -p or -o is specified.
-But check that -p0 still work.
-
 * Checks if splitting hash/parity computation in 4K pages
 can improve speed in sync. That should increase cache locality,
 becase we read the data two times for hash and and parity,
diff --git a/scrub.c b/scrub.c
index 09d43787..6eed9fb1 100644
--- a/scrub.c
+++ b/scrub.c
@@ -459,6 +459,20 @@ bail:
 	return 0;
 }
 
+/**
+ * Returns a * b / c approximated to the upper value.
+ */
+static uint32_t md(uint32_t a, uint32_t b, uint32_t c)
+{
+	uint64_t v = a;
+
+	v *= b;
+	v += c - 1;
+	v /= c;
+
+	return v;
+}
+
 int state_scrub(struct snapraid_state* state, int percentage, int olderthan)
 {
 	block_off_t blockmax;
@@ -490,21 +504,21 @@ int state_scrub(struct snapraid_state* state, int percentage, int olderthan)
 		/* scrub the specified amount of blocks */
 		countlimit = state->opt.force_scrub;
 		recentlimit = now;
-	} else if (percentage != -1 || olderthan != -1) {
+	} else {
+		/* by default scrub 1/12 of the array */
+		countlimit = md(blockmax, 1, 12);
+
+		/* by default use a 10 day time limit */
+		recentlimit = now - 10 * 24 * 3600;
+
 		if (percentage != -1)
-			countlimit = (blockmax * (uint64_t)percentage + 99) / 100;
+			countlimit = md(blockmax, percentage, 100);
 		else
 			countlimit = blockmax;
 		if (olderthan != -1)
 			recentlimit = now - olderthan * 24 * 3600;
 		else
 			recentlimit = now;
-	} else {
-		/* by default scrub 1/12 of the array */
-		countlimit = blockmax / 12;
-
-		/* by default use a 10 day time limit */
-		recentlimit = now - 10 * 24 * 3600;
 	}
 
 	/* identify the time limit */
diff --git a/snapraid.1 b/snapraid.1
index 04cc0bbd..b55678cc 100644
--- a/snapraid.1
+++ b/snapraid.1
@@ -557,8 +557,7 @@ at least one time every two months.
 .PP
 You can use the \-p, \-\-percentage option to specify a different amount,
 and the \-o, \-\-older\-than option to specify a different age in days.
-Note that if only one of \-p and \-o is specified the default value of
-the other option is not used.
+You can have a full scrub with \(a"\-p100 \-o0\(a".
 .PP
 Any silent error identified is recorded in the content file,
 and it\(cqs listed in the \(a"status\(a" command until it\(cqs fixed calling
diff --git a/snapraid.d b/snapraid.d
index 59a7fd60..8f2b6477 100644
--- a/snapraid.d
+++ b/snapraid.d
@@ -315,8 +315,7 @@ Commands
 
 	You can use the -p, --percentage option to specify a different amount,
 	and the -o, --older-than option to specify a different age in days.
-	Note that if only one of -p and -o is specified the default value of
-	the other option is not used.
+	You can have a full scrub with "-p100 -o0".
 
 	Any silent error identified is recorded in the content file,
 	and it's listed in the "status" command until it's fixed calling
diff --git a/snapraid.txt b/snapraid.txt
index e109434e..71cd1bdd 100644
--- a/snapraid.txt
+++ b/snapraid.txt
@@ -343,8 +343,7 @@ at least one time every two months.
 
 You can use the -p, --percentage option to specify a different amount,
 and the -o, --older-than option to specify a different age in days.
-Note that if only one of -p and -o is specified the default value of
-the other option is not used.
+You can have a full scrub with "-p100 -o0".
 
 Any silent error identified is recorded in the content file,
 and it's listed in the "status" command until it's fixed calling