lsblk: add support for discard topology (-D option)

I got tired of poking around in sysfs to find the discard topology.
Here's a patch against lsblk that adds a -D option to present this
information in a human-readable form:

NAME                  DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
sda                          0        0B       0B         0
└─sda1                       0        0B       0B         0
sdb                          0      512B       2G         1
└─sdb1                       0      512B       2G         1

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

diff --git a/misc-utils/lsblk.8 b/misc-utils/lsblk.8
index 38ff48f0002babee8c31d2f96d420747f3888223..d7d7aa8b4d8b68deb62be43ba12a34a0443fe141 100644 (file)
--- a/misc-utils/lsblk.8
+++ b/misc-utils/lsblk.8
@@ -29,6 +29,8 @@ Print the SIZE column in bytes rather than in human-readable format.
 .IP "\fB\-d, \-\-nodeps\fP"
 Don't print device holders or slaves.  For example "lsblk --nodeps /dev/sda" prints
 information about the sda device only.
+.IP "\fB\-D, \-\-discard\fP"
+Print information about the discard (TRIM, UNMAP) capabilities for each device.
 .IP "\fB\-e, \-\-exclude \fIlist\fP
 Exclude the devices specified by a comma-separated \fIlist\fR of major device numbers.
 Note that RAM disks (major=1) are excluded by default.

diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
index 38326d08ab698716bc160d494ce4a5ed8cfce772..dc4e15aafd1b4266a37a76f5d67c4d71c5315981 100644 (file)
--- a/misc-utils/lsblk.c
+++ b/misc-utils/lsblk.c
@@ -77,6 +77,10 @@ enum {
        COL_ROTA,
        COL_SCHED,
        COL_TYPE,
+       COL_DALIGN,
+       COL_DGRAN,
+       COL_DMAX,
+       COL_DZERO,
 
        __NCOLUMNS
 };
@@ -112,8 +116,11 @@ static struct colinfo infos[__NCOLUMNS] = {
        [COL_PHYSEC] = { "PHY-SEC", 7, TT_FL_RIGHT, N_("physical sector size") },
        [COL_LOGSEC] = { "LOG-SEC", 7, TT_FL_RIGHT, N_("logical sector size") },
        [COL_SCHED]  = { "SCHED",   0.1, 0, N_("I/O scheduler name") },
-       [COL_TYPE]   = { "TYPE",    4, 0, N_("device type") }
-
+       [COL_TYPE]   = { "TYPE",    4, 0, N_("device type") },
+       [COL_DALIGN] = { "DISC-ALN", 6, TT_FL_RIGHT, N_("discard alignment offset") },
+       [COL_DGRAN]  = { "DISC-GRAN", 6, TT_FL_RIGHT, N_("discard granularity") },
+       [COL_DMAX]   = { "DISC-MAX", 6, TT_FL_RIGHT, N_("discard max bytes") },
+       [COL_DZERO]  = { "DISC-ZERO", 1, TT_FL_RIGHT, N_("discard zeroes data") },
 };
 
 struct lsblk {
@@ -702,6 +709,31 @@ 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_DALIGN:
+               p = sysfs_strdup(cxt, "discard_alignment");
+               if (p)
+                       tt_line_set_data(ln, col, p);
+               break;
+       case COL_DGRAN:
+               p = sysfs_strdup(cxt, "queue/discard_granularity");
+               if (!lsblk->bytes)
+                       p = size_to_human_string(atoi(p));
+               if (p)
+                       tt_line_set_data(ln, col, p);
+               break;
+       case COL_DMAX:
+               p = sysfs_strdup(cxt, "queue/discard_max_bytes");
+
+               if (!lsblk->bytes)
+                       p = size_to_human_string(atoi(p));
+               if (p)
+                       tt_line_set_data(ln, col, p);
+               break;
+       case COL_DZERO:
+               p = sysfs_strdup(cxt, "queue/discard_zeroes_data");
+               if (p)
+                       tt_line_set_data(ln, col, p);
+               break;
        };
 }
 
@@ -930,6 +962,7 @@ static void __attribute__((__noreturn__)) help(FILE *out)
                " -a, --all            print all devices\n"
                " -b, --bytes          print SIZE in bytes rather than in human readable format\n"
                " -d, --nodeps         don't print slaves or holders\n"
+               " -D, --discard        print discard capabilities\n"
                " -e, --exclude <list> exclude devices by major number (default: RAM disks)\n"
                " -f, --fs             output info about filesystems\n"
                " -h, --help           usage information (this)\n"
@@ -967,6 +1000,7 @@ int main(int argc, char *argv[])
                { "all",        0, 0, 'a' },
                { "bytes",      0, 0, 'b' },
                { "nodeps",     0, 0, 'd' },
+               { "discard",    0, 0, 'D' },
                { "help",       0, 0, 'h' },
                { "output",     1, 0, 'o' },
                { "perms",      0, 0, 'm' },
@@ -987,7 +1021,7 @@ int main(int argc, char *argv[])
        lsblk = &_ls;
        memset(lsblk, 0, sizeof(*lsblk));
 
-       while((c = getopt_long(argc, argv, "abde:fhlnmo:irt", longopts, NULL)) != -1) {
+       while((c = getopt_long(argc, argv, "abdDe:fhlnmo:irt", longopts, NULL)) != -1) {
                switch(c) {
                case 'a':
                        lsblk->all_devices = 1;
@@ -998,6 +1032,13 @@ int main(int argc, char *argv[])
                case 'd':
                        lsblk->nodeps = 1;
                        break;
+               case 'D':
+                       columns[ncolumns++] = COL_NAME;
+                       columns[ncolumns++] = COL_DALIGN;
+                       columns[ncolumns++] = COL_DGRAN;
+                       columns[ncolumns++] = COL_DMAX;
+                       columns[ncolumns++] = COL_DZERO;
+                       break;
                case 'e':
                        parse_excludes(optarg);
                        break;