[dm-devel] [multipath-tools] [patch] retry tur on reset

[Brian Wong <bwong pillardata com>]

hi christophe,

this patch retries the tur sgio in the tur checker when the status
returned is a scsi reset.  

cheers,

brian

diff --git a/libcheckers/tur.c b/libcheckers/tur.c
index d40a273..463dba9 100644
--- a/libcheckers/tur.c
+++ b/libcheckers/tur.c
@@ -43,7 +43,7 @@ tur (struct checker * c)
 	struct sg_io_hdr io_hdr;
         unsigned char turCmdBlk[TUR_CMD_LEN] = { 0x00, 0, 0, 0, 0, 0 };
         unsigned char sense_buffer[32];
-
+	
         memset(&io_hdr, 0, sizeof (struct sg_io_hdr));
         io_hdr.interface_id = 'S';
         io_hdr.cmd_len = sizeof (turCmdBlk);
@@ -53,10 +53,28 @@ tur (struct checker * c)
         io_hdr.sbp = sense_buffer;
         io_hdr.timeout = 20000;
         io_hdr.pack_id = 0;
-        if (ioctl(c->fd, SG_IO, &io_hdr) < 0) {
+ do_sgio:
+	if (ioctl(c->fd, SG_IO, &io_hdr) < 0) {
 		MSG(c, MSG_TUR_DOWN);
-                return PATH_DOWN;
-        }
+		return PATH_DOWN;
+	}
+	if (io_hdr.status == SCSI_CHECK_CONDITION) {
+		if (io_hdr.sbp && (io_hdr.sb_len_wr > 2)) {
+			int		sense_key;
+			unsigned char *	sense_buffer = io_hdr.sbp;
+			
+			if (sense_buffer[0] & 0x2)
+				sense_key = sense_buffer[1] & 0xf;
+			else
+				sense_key = sense_buffer[2] & 0xf;
+
+			/* retry UA, SCSI RESET conditions */
+			if (sense_key == 0x06 && sense_buffer[12] == 0x29) {
+				goto do_sgio;
+			}
+			
+		}
+	}
         if (io_hdr.info & SG_INFO_OK_MASK) {
 		MSG(c, MSG_TUR_DOWN);
                 return PATH_DOWN;