svn commit: r221967 - head/sbin/geom/class/part

[Andrey V. Elsukov]

Author: ae
Date: Sun May 15 16:16:48 2011
New Revision: 221967
URL: http://svn.freebsd.org/changeset/base/221967

Log:
  Some partitioning schemes want to have partitions that are aligned
  with geometry. And they do recalculation of user specified parameters.
  MBR, PC98, VTOC8, EBR schemes are doing that. For these schemes an
  auto alignment feature (ie. gpart add -a alignment) would not work.
  But it can work for GPT and BSD schemes. BSD scheme usualy is created
  inside MBR, so we can use knowledge about offset of MBR partition to
  calculate aligned values for BSD partitions.
  
  Use "offset" attribute of the parent provider for better alignment.
  
  MFC after:	2 weeks

Modified:
  head/sbin/geom/class/part/geom_part.c

Modified: head/sbin/geom/class/part/geom_part.c
==============================================================================
--- head/sbin/geom/class/part/geom_part.c	Sun May 15 16:15:39 2011	(r221966)
+++ head/sbin/geom/class/part/geom_part.c	Sun May 15 16:16:48 2011	(r221967)
@@ -416,7 +416,7 @@ gpart_autofill(struct gctl_req *req)
 	struct gprovider *pp;
 	off_t first, last, a_first;
 	off_t size, start, a_lba;
-	off_t lba, len, alignment;
+	off_t lba, len, alignment, offset;
 	uintmax_t grade;
 	const char *s;
 	int error, has_size, has_start, has_alignment;
@@ -467,8 +467,6 @@ gpart_autofill(struct gctl_req *req)
 		error = g_parse_lba(s, pp->lg_sectorsize, &size);
 		if (error)
 			errc(EXIT_FAILURE, error, "Invalid size param");
-		if (size > alignment)
-			size = ALIGNDOWN(size, alignment);
 	}
 
 	s = gctl_get_ascii(req, "start");
@@ -478,22 +476,29 @@ gpart_autofill(struct gctl_req *req)
 		error = g_parse_lba(s, pp->lg_sectorsize, &start);
 		if (error)
 			errc(EXIT_FAILURE, error, "Invalid start param");
-		start = ALIGNUP(start, alignment);
 	}
 
 	/* No autofill necessary. */
 	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;
+	start = ALIGNUP(start + offset, alignment);
+	if (size + offset > alignment)
+		size = ALIGNDOWN(size + offset, alignment);
+
 	first = (off_t)strtoimax(find_geomcfg(gp, "first"), NULL, 0);
 	last = (off_t)strtoimax(find_geomcfg(gp, "last"), NULL, 0);
 	grade = ~0ULL;
-	a_first = ALIGNUP(first, alignment);
-	last = ALIGNDOWN(last, alignment);
+	a_first = ALIGNUP(first + offset, alignment);
+	last = ALIGNDOWN(last + offset, alignment);
 	while ((pp = find_provider(gp, first)) != NULL) {
 		s = find_provcfg(pp, "start");
 		lba = (off_t)strtoimax(s, NULL, 0);
-		a_lba = ALIGNDOWN(lba, alignment);
+		a_lba = ALIGNDOWN(lba + offset, alignment);
 		if (first < a_lba && a_first < a_lba) {
 			/* Free space [first, lba> */
 			len = a_lba - a_first;
@@ -519,7 +524,7 @@ gpart_autofill(struct gctl_req *req)
 
 		s = find_provcfg(pp, "end");
 		first = (off_t)strtoimax(s, NULL, 0) + 1;
-		a_first = ALIGNUP(first, alignment);
+		a_first = ALIGNUP(first + offset, alignment);
 	}
 	if (a_first <= last) {
 		/* Free space [first-last] */
@@ -543,12 +548,11 @@ gpart_autofill(struct gctl_req *req)
 			}
 		}
 	}
-
 	if (grade == ~0ULL) {
 		geom_deletetree(&mesh);
 		return (ENOSPC);
 	}
-
+	start -= offset;	/* Return back to real offset */
 done:
 	snprintf(ssize, sizeof(ssize), "%jd", (intmax_t)size);
 	gctl_change_param(req, "size", -1, ssize);