lsblk: improve discard support

Use atol() instead of atoi() when extracting discard_max_bytes.

Only print discard_alignment and discard_zeroes_data if the device
supports discard. This prevents printing of undefined values with older
kernels.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
index 5d34aebf42a980aa699a79ecfbe28fe688524f3e..02061629e72ebc6e9b7fab5a6701116cf5691412 100644 (file)
--- a/misc-utils/lsblk.c
+++ b/misc-utils/lsblk.c
@@ -162,6 +162,7 @@ struct blkdev_cxt {
                                 * /sys/block/.../holders + number of partition */
        int nslaves;            /* # of devices this device maps to */
        int maj, min;           /* devno */
+       int discard;            /* supports discard */
 
        uint64_t size;          /* device size */
 };
@@ -555,8 +556,10 @@ static void set_tt_data(struct blkdev_cxt *cxt, int col, int id, struct tt_line
                break;
        case COL_DALIGN:
                p = sysfs_strdup(&cxt->sysfs, "discard_alignment");
-               if (p)
+               if (cxt->discard && p)
                        tt_line_set_data(ln, col, p);
+               else
+                       tt_line_set_data(ln, col, "0");
                break;
        case COL_DGRAN:
                p = sysfs_strdup(&cxt->sysfs, "queue/discard_granularity");
@@ -567,16 +570,17 @@ static void set_tt_data(struct blkdev_cxt *cxt, int col, int id, struct tt_line
                break;
        case COL_DMAX:
                p = sysfs_strdup(&cxt->sysfs, "queue/discard_max_bytes");
-
                if (!lsblk->bytes)
-                       p = size_to_human_string(atoi(p));
+                       p = size_to_human_string(atol(p));
                if (p)
                        tt_line_set_data(ln, col, p);
                break;
        case COL_DZERO:
                p = sysfs_strdup(&cxt->sysfs, "queue/discard_zeroes_data");
-               if (p)
+               if (cxt->discard && p)
                        tt_line_set_data(ln, col, p);
+               else
+                       tt_line_set_data(ln, col, "0");
                break;
        };
 }
@@ -616,6 +620,7 @@ static int set_cxt(struct blkdev_cxt *cxt,
        cxt->min = minor(devno);
 
        cxt->size = sysfs_read_u64(&cxt->sysfs, "size") << 9;
+       cxt->discard = sysfs_read_int(&cxt->sysfs, "queue/discard_granularity");
 
        /* Ignore devices of zero size */
        if (!lsblk->all_devices && cxt->size == 0)