lsblk: add SCSI H:C:T:L attribute

For block devices it is sometimes useful to print SCSI device ID"
Host:Channel:Target:LUN.

Patch adds column name HCTL which can be used in lsblk.

Signed-off-by: Milan Broz <mbroz@redhat.com>

diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
index 1118e7eb94eee32e68460e1fe018ef91fec4b928..7101eed4d7474c7156aea04138f2fa6771c5b58d 100644 (file)
--- a/misc-utils/lsblk.c
+++ b/misc-utils/lsblk.c
@@ -98,6 +98,7 @@ enum {
        COL_WWN,
        COL_RAND,
        COL_PKNAME,
+       COL_HCTL,
 };
 
 /* column names */
@@ -146,6 +147,7 @@ static struct colinfo infos[] = {
        [COL_DMAX]   = { "DISC-MAX", 6, TT_FL_RIGHT, N_("discard max bytes") },
        [COL_DZERO]  = { "DISC-ZERO", 1, TT_FL_RIGHT, N_("discard zeroes data") },
        [COL_WWN]    = { "WWN",     18, 0, N_("unique storage identifier") },
+       [COL_HCTL]   = { "HCTL", 10, 0, N_("Host:Channel:Target:Lun for SCSI") },
 };
 
 struct lsblk {
@@ -573,6 +575,27 @@ static char *get_type(struct blkdev_cxt *cxt)
        return res;
 }
 
+/* H:C:T:L - Host:Channel:Target:LUN */
+static int get_hctl(struct blkdev_cxt *cxt, int *h, int *c, int *t, int *l)
+{
+       char buf[PATH_MAX], *hctl;
+       ssize_t len;
+
+       len = sysfs_readlink(&cxt->sysfs, "device", buf, sizeof(buf));
+       if (len < 0)
+               return 0;
+
+       buf[len] = '\0';
+       hctl = strrchr(buf, '/') + 1;
+       if (!hctl)
+               return 0;
+
+       if (sscanf(hctl, "%d:%d:%d:%d", h, c, t, l) != 4)
+               return 0;
+
+       return 1;
+}
+
 #define is_parsable(_l)        (((_l)->tt->flags & TT_FL_RAW) || \
                         ((_l)->tt->flags & TT_FL_EXPORT))
 
@@ -771,6 +794,15 @@ static void set_tt_data(struct blkdev_cxt *cxt, int col, int id, struct tt_line
                if (p)
                        tt_line_set_data(ln, col, p);
                break;
+       case COL_HCTL:
+       {
+               int h, c, t, l;
+               if (get_hctl(cxt, &h, &c, &t, &l)) {
+                       snprintf(buf, sizeof(buf), "%d:%d:%d:%d", h, c, t, l);
+                       tt_line_set_data(ln, col, xstrdup(buf));
+               }
+               break;
+       }
        case COL_DALIGN:
                p = sysfs_strdup(&cxt->sysfs, "discard_alignment");
                if (cxt->discard && p)