From a6c21ef2d1778055a5f0361ab75156cb3c8a58fc Mon Sep 17 00:00:00 2001
From: "Andrey V. Elsukov" <ae@FreeBSD.org>
Date: Thu, 2 Jun 2011 21:59:21 +0000
Subject: [PATCH] Use stripesize and stripeoffset in the automatic calculation
 of partition offsets. If user requests specific alignment and provider's
 stripesize is not zero, then use a least common multiple from the stripesize
 and user specified value. Also fix "gpart resize" implementation: do not try
 to align the partition size, because the start offset may be not aligned.
 Instead align the end offset and then calculate size. Also use stripesize and
 stripeoffset for "gpart resize" command.

---
 sbin/geom/class/part/geom_part.c | 51 +++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 18 deletions(-)

diff --git a/sbin/geom/class/part/geom_part.c b/sbin/geom/class/part/geom_part.c
index 93b28ac8c9c5..a433a0fcdad6 100644
--- a/sbin/geom/class/part/geom_part.c
+++ b/sbin/geom/class/part/geom_part.c
@@ -306,7 +306,7 @@ gpart_autofill_resize(struct gctl_req *req)
 	struct ggeom *gp;
 	struct gprovider *pp;
 	off_t last, size, start, new_size;
-	off_t lba, new_lba, alignment;
+	off_t lba, new_lba, alignment, offset;
 	const char *s;
 	int error, idx;
 
@@ -341,6 +341,9 @@ gpart_autofill_resize(struct gctl_req *req)
 			errc(EXIT_FAILURE, error, "Invalid alignment param");
 		if (alignment == 0)
 			errx(EXIT_FAILURE, "Invalid alignment param");
+		lba = pp->lg_stripesize / pp->lg_sectorsize;
+		if (lba % alignment)
+			alignment = g_lcm(lba, alignment);
 	}
 	error = gctl_delete_param(req, "alignment");
 	if (error)
@@ -356,12 +359,10 @@ gpart_autofill_resize(struct gctl_req *req)
 		/* no autofill necessary. */
 		if (alignment == 1)
 			goto done;
-		if (new_size > alignment)
-			new_size = ALIGNDOWN(new_size, alignment);
 	}
 
+	offset = pp->lg_stripeoffset / pp->lg_sectorsize;
 	last = (off_t)strtoimax(find_geomcfg(gp, "last"), NULL, 0);
-	last = ALIGNDOWN(last, alignment);
 	LIST_FOREACH(pp, &gp->lg_provider, lg_provider) {
 		s = find_provcfg(pp, "index");
 		if (s == NULL)
@@ -375,24 +376,32 @@ gpart_autofill_resize(struct gctl_req *req)
 	s = find_provcfg(pp, "start");
 	start = (off_t)strtoimax(s, NULL, 0);
 	s = find_provcfg(pp, "end");
-	lba = (off_t)strtoimax(s, NULL, 0) + 1;
+	lba = (off_t)strtoimax(s, NULL, 0);
+	size = lba - start + 1;
 
-	if (lba > last) {
-		geom_deletetree(&mesh);
-		return (ENOSPC);
+	if (new_size > 0 && new_size <= size) {
+		/* The start offset may be not aligned, so we align the end
+		 * offset and then calculate the size.
+		 */
+		new_size = ALIGNDOWN(start + offset + new_size,
+		    alignment) - start - offset;
+		goto done;
 	}
-	size = lba - start;
-	pp = find_provider(gp, lba);
-	if (pp == NULL)
-		new_size = ALIGNDOWN(last - start + 1, alignment);
-	else {
+
+	pp = find_provider(gp, lba + 1);
+	if (pp == NULL) {
+		new_size = ALIGNDOWN(last + offset + 1, alignment) -
+		    start - offset;
+		if (new_size < size)
+			return (ENOSPC);
+	} else {
 		s = find_provcfg(pp, "start");
 		new_lba = (off_t)strtoimax(s, NULL, 0);
 		/*
 		 * Is there any free space between current and
 		 * next providers?
 		 */
-		new_lba = ALIGNUP(new_lba, alignment);
+		new_lba = ALIGNDOWN(new_lba + offset, alignment) - offset;
 		if (new_lba > lba)
 			new_size = new_lba - start;
 		else {
@@ -482,10 +491,16 @@ gpart_autofill(struct gctl_req *req)
 	if (has_size && has_start && !has_alignment)
 		goto done;
 
-	/* Adjust parameters to offset value for better alignment */
-	s = find_provcfg(pp, "offset");
-	offset = (s == NULL) ? 0:
-	    (off_t)strtoimax(s, NULL, 0) / pp->lg_sectorsize;
+	/*
+	 * If stripesize is not zero, then recalculate alignment value.
+	 * Use LCM from stripesize and user specified alignment.
+	 */
+	len = pp->lg_stripesize / pp->lg_sectorsize;
+	if (len % alignment)
+		alignment = g_lcm(len, alignment);
+
+	/* Adjust parameters to stripeoffset */
+	offset = pp->lg_stripeoffset / pp->lg_sectorsize;
 	start = ALIGNUP(start + offset, alignment);
 	if (size + offset > alignment)
 		size = ALIGNDOWN(size + offset, alignment);