- Add kern.geom.raid3.disconnect_on_failure sysctl/tunnable (default to 1

  to preserve currect behaviour). When set to 0, components are not
  disconnected - graid3 will try to still use them (only first error will
  be logged). This is helpful when we have two broken components, but in
  different places, so actually all data is available.
  Such buggy component will be visible in 'graid3 list' output with flag
  BROKEN.
- Never disconnect the last valid component. If we detect errors there we
  will just pass them up. This wasn't reasonable to deny access to the
  whole provider because of one broken sector.

Prodded by:	ru
MFC after:	3 days

2 files changed, 76 insertions, 31 deletions

diff --git a/sys/geom/raid3/g_raid3.c b/sys/geom/raid3/g_raid3.c
index 941ed94..0971a46 100644
--- a/sys/geom/raid3/g_raid3.c
+++ b/sys/geom/raid3/g_raid3.c
@@ -70,6 +70,9 @@ static u_int g_raid3_syncs_per_sec = 1000;
 SYSCTL_UINT(_kern_geom_raid3, OID_AUTO, syncs_per_sec, CTLFLAG_RW,
     &g_raid3_syncs_per_sec, 0,
     "Number of synchronizations requests per second");
+static u_int g_raid3_disconnect_on_failure = 1;
+SYSCTL_UINT(_kern_geom_raid3, OID_AUTO, disconnect_on_failure, CTLFLAG_RW,
+    &g_raid3_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
 
 static u_int g_raid3_n64k = 50;
 TUNABLE_INT("kern.geom.raid3.n64k", &g_raid3_n64k);
@@ -647,9 +650,23 @@ g_raid3_write_metadata(struct g_raid3_disk *disk, struct g_raid3_metadata *md)
 	g_topology_lock();
 	free(sector, M_RAID3);
 	if (error != 0) {
-		disk->d_softc->sc_bump_id = G_RAID3_BUMP_GENID;
-		g_raid3_event_send(disk, G_RAID3_DISK_STATE_DISCONNECTED,
-		    G_RAID3_EVENT_DONTWAIT);
+		if ((disk->d_flags & G_RAID3_DISK_FLAG_BROKEN) == 0) {												      
+			G_RAID3_DEBUG(0, "Cannot write metadata on %s "												     
+			    "(device=%s, error=%d).",															
+			    g_raid3_get_diskname(disk), sc->sc_name, error);												
+			disk->d_flags |= G_RAID3_DISK_FLAG_BROKEN;													  
+		} else {																		     
+			G_RAID3_DEBUG(1, "Cannot write metadata on %s "												     
+			    "(device=%s, error=%d).",															
+			    g_raid3_get_diskname(disk), sc->sc_name, error);												
+		}																			    
+		if (g_raid3_disconnect_on_failure &&															
+		    sc->sc_state == G_RAID3_DEVICE_STATE_COMPLETE) {
+			sc->sc_bump_id |= G_RAID3_BUMP_GENID;												    
+			g_raid3_event_send(disk,															    
+			    G_RAID3_DISK_STATE_DISCONNECTED,														
+			    G_RAID3_EVENT_DONTWAIT);															
+		}		 
 	}
 	return (error);
 }
@@ -1069,18 +1086,6 @@ g_raid3_gather(struct bio *pbp)
 		/*
 		 * Found failed request.
 		 */
-		G_RAID3_LOGREQ(0, cbp, "Request failed.");
-		disk = cbp->bio_caller2;
-		if (disk != NULL) {
-			/*
-			 * Actually this is pointless to bump genid,
-			 * because whole device is fucked up.
-			 */
-			sc->sc_bump_id |= G_RAID3_BUMP_GENID;
-			g_raid3_event_send(disk,
-			    G_RAID3_DISK_STATE_DISCONNECTED,
-			    G_RAID3_EVENT_DONTWAIT);
-		}
 		if (fbp == NULL) {
 			if ((pbp->bio_pflags & G_RAID3_BIO_PFLAG_DEGRADED) != 0) {
 				/*
@@ -1099,6 +1104,24 @@ g_raid3_gather(struct bio *pbp)
 			if (pbp->bio_error == 0)
 				pbp->bio_error = fbp->bio_error;
 		}
+		disk = cbp->bio_caller2;
+		if (disk == NULL)
+			continue;
+		if ((disk->d_flags & G_RAID3_DISK_FLAG_BROKEN) == 0) {
+			disk->d_flags |= G_RAID3_DISK_FLAG_BROKEN;
+			G_RAID3_LOGREQ(0, cbp, "Request failed (error=%d).",
+			    cbp->bio_error);
+		} else {
+			G_RAID3_LOGREQ(1, cbp, "Request failed (error=%d).",
+			    cbp->bio_error);
+		}
+		if (g_raid3_disconnect_on_failure &&
+		    sc->sc_state == G_RAID3_DEVICE_STATE_COMPLETE) {
+			sc->sc_bump_id |= G_RAID3_BUMP_GENID;
+			g_raid3_event_send(disk,
+			    G_RAID3_DISK_STATE_DISCONNECTED,
+			    G_RAID3_EVENT_DONTWAIT);
+		}
 	}
 	if (pbp->bio_error != 0)
 		goto finish;
@@ -1238,22 +1261,42 @@ g_raid3_regular_request(struct bio *cbp)
 
 		pbp->bio_completed = pbp->bio_length;
 		while ((cbp = G_RAID3_HEAD_BIO(pbp)) != NULL) {
-			if (cbp->bio_error != 0) {
-				disk = cbp->bio_caller2;
-				if (disk != NULL) {
-					sc->sc_bump_id |= G_RAID3_BUMP_GENID;
-					g_raid3_event_send(disk,
-					    G_RAID3_DISK_STATE_DISCONNECTED,
-					    G_RAID3_EVENT_DONTWAIT);
-				}
-				if (error == 0)
-					error = cbp->bio_error;
-				else if (pbp->bio_error == 0) {
-					/*
-					 * Next failed request, that's too many.
-					 */
-					pbp->bio_error = error;
-				}
+			if (cbp->bio_error == 0) {
+				g_raid3_destroy_bio(sc, cbp);
+				continue;
+			}
+
+			if (error == 0)
+				error = cbp->bio_error;
+			else if (pbp->bio_error == 0) {
+				/*
+				 * Next failed request, that's too many.
+				 */
+				pbp->bio_error = error;
+			}
+
+			disk = cbp->bio_caller2;
+			if (disk == NULL) {
+				g_raid3_destroy_bio(sc, cbp);
+				continue;
+			}
+
+			if ((disk->d_flags & G_RAID3_DISK_FLAG_BROKEN) == 0) {
+				disk->d_flags |= G_RAID3_DISK_FLAG_BROKEN;
+				G_RAID3_LOGREQ(0, cbp,
+				    "Request failed (error=%d).",
+				    cbp->bio_error);
+			} else {
+				G_RAID3_LOGREQ(1, cbp,
+				    "Request failed (error=%d).",
+				    cbp->bio_error);
+			}
+			if (g_raid3_disconnect_on_failure &&
+			    sc->sc_state == G_RAID3_DEVICE_STATE_COMPLETE) {
+				sc->sc_bump_id |= G_RAID3_BUMP_GENID;
+				g_raid3_event_send(disk,
+				    G_RAID3_DISK_STATE_DISCONNECTED,
+				    G_RAID3_EVENT_DONTWAIT);
 			}
 			g_raid3_destroy_bio(sc, cbp);
 		}
@@ -2999,6 +3042,7 @@ g_raid3_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
 			ADD_FLAG(G_RAID3_DISK_FLAG_SYNCHRONIZING,
 			    "SYNCHRONIZING");
 			ADD_FLAG(G_RAID3_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
+			ADD_FLAG(G_RAID3_DISK_FLAG_BROKEN, "BROKEN");
 #undef	ADD_FLAG
 		}
 		sbuf_printf(sb, "</Flags>\n");
diff --git a/sys/geom/raid3/g_raid3.h b/sys/geom/raid3/g_raid3.h
index c7df788..ab97593 100644
--- a/sys/geom/raid3/g_raid3.h
+++ b/sys/geom/raid3/g_raid3.h
@@ -49,6 +49,7 @@
 #define	G_RAID3_DISK_FLAG_SYNCHRONIZING	0x0000000000000002ULL
 #define	G_RAID3_DISK_FLAG_FORCE_SYNC	0x0000000000000004ULL
 #define	G_RAID3_DISK_FLAG_HARDCODED	0x0000000000000008ULL
+#define	G_RAID3_DISK_FLAG_BROKEN	0x0000000000000010ULL
 #define	G_RAID3_DISK_FLAG_MASK		(G_RAID3_DISK_FLAG_DIRTY |	\
 					 G_RAID3_DISK_FLAG_SYNCHRONIZING | \
 					 G_RAID3_DISK_FLAG_FORCE_SYNC)