svn commit: r218226 - projects/graid/head/sys/geom/raid

[Alexander Motin]

Author: mav
Date: Thu Feb  3 15:46:54 2011
New Revision: 218226
URL: http://svn.freebsd.org/changeset/base/218226

Log:
  When we got new disk, prefer to replace OFFLINE disk and only then FAILED.
  FAILED disk theoretically may still contain some usable information, while
  OFFLINE is definitely not. Also it may happen that new disk is really the
  one OFFLINE we are missing, and so information still could be restored.
  That's all about luck and magic, but why not if we are not loosing anything?

Modified:
  projects/graid/head/sys/geom/raid/md_intel.c

Modified: projects/graid/head/sys/geom/raid/md_intel.c
==============================================================================
--- projects/graid/head/sys/geom/raid/md_intel.c	Thu Feb  3 15:19:18 2011	(r218225)
+++ projects/graid/head/sys/geom/raid/md_intel.c	Thu Feb  3 15:46:54 2011	(r218226)
@@ -506,7 +506,7 @@ g_raid_md_intel_start_disk(struct g_raid
 {
 	struct g_raid_softc *sc;
 	struct g_raid_subdisk *sd, *tmpsd;
-	struct g_raid_disk *olddisk;
+	struct g_raid_disk *olddisk, *tmpdisk;
 	struct g_raid_md_object *md;
 	struct g_raid_md_intel_object *mdi;
 	struct g_raid_md_intel_perdisk *pd, *oldpd;
@@ -534,13 +534,16 @@ g_raid_md_intel_start_disk(struct g_raid
 		/* If we are in the start process, that's all for now. */
 		if (!mdi->mdio_started)
 			goto nofit;
-		/* If we have already started - try to get use of the disk. */
-		TAILQ_FOREACH(olddisk, &sc->sc_disks, d_next) {
-			if (olddisk->d_state != G_RAID_DISK_S_OFFLINE &&
-			    olddisk->d_state != G_RAID_DISK_S_FAILED)
+		/*
+		 * If we have already started - try to get use of the disk.
+		 * Try to replace OFFLINE disks first, then FAILED.
+		 */
+		TAILQ_FOREACH(tmpdisk, &sc->sc_disks, d_next) {
+			if (tmpdisk->d_state != G_RAID_DISK_S_OFFLINE &&
+			    tmpdisk->d_state != G_RAID_DISK_S_FAILED)
 				continue;
 			/* Make sure this disk is big enough. */
-			TAILQ_FOREACH(sd, &olddisk->d_subdisks, sd_next) {
+			TAILQ_FOREACH(sd, &tmpdisk->d_subdisks, sd_next) {
 				if (sd->sd_offset + sd->sd_size + 4096 >
 				    (off_t)pd->pd_disk_meta.sectors * 512) {
 					G_RAID_DEBUG(1,
@@ -554,7 +557,11 @@ g_raid_md_intel_start_disk(struct g_raid
 			}
 			if (sd != NULL)
 				continue;
-			break;
+			if (tmpdisk->d_state == G_RAID_DISK_S_OFFLINE) {
+				olddisk = tmpdisk;
+				break;
+			} else if (olddisk == NULL)
+				olddisk = tmpdisk;
 		}
 		if (olddisk == NULL) {
 nofit: