lsblk: add --include option

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/lsblk.8 b/misc-utils/lsblk.8
index 79173dae48a1dd446d5f4eb135f14bb5d11b78c4..227da9aa30ebdf49d46c69d014a9d3f45f61eddb 100644 (file)
--- a/misc-utils/lsblk.8
+++ b/misc-utils/lsblk.8
@@ -23,7 +23,8 @@ by default.  Use
 to get a list of all available columns.
 .SH OPTIONS
 .IP "\fB\-a, \-\-all\fP"
-List all block devices.
+.B lsblk
+does not list empty devices by default. This option disables this restriction.
 .IP "\fB\-b, \-\-bytes\fP"
 Print the SIZE column in bytes rather than in human-readable format.
 .IP "\fB\-d, \-\-nodeps\fP"
@@ -33,7 +34,11 @@ information about the sda device only.
 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.
+Note that RAM disks (major=1) are excluded by default. The filter is applied to the top-level
+devices only.
+.IP "\fB\-I, \-\-include \fIlist\fP
+Include devices specified by a comma-separated \fIlist\fR of major device numbers only.
+The filter is applied to the top-level devices.
 .IP "\fB\-f, \-\-fs\fP
 Output info about filesystems.  This option is equivalent to "-o NAME,FSTYPE,LABEL,MOUNTPOINT".
 The authoritative information about filesystems and raids is provided by the

diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
index f635a4a13522000627759d6ad33ab1c0215b52c1..0bcdbfceee8b0448353a6f5be7a98b121c81061c 100644 (file)
--- a/misc-utils/lsblk.c
+++ b/misc-utils/lsblk.c
@@ -142,7 +142,7 @@ static struct colinfo infos[] = {
 
 struct lsblk {
        struct tt *tt;                  /* output table */
-       unsigned int all_devices:1;     /* print all devices */
+       unsigned int all_devices:1;     /* print all devices, icluding empty */
        unsigned int bytes:1;           /* print SIZE in bytes */
        unsigned int inverse:1;         /* print inverse dependencies */
        unsigned int nodeps:1;          /* don't print slaves/holders */
@@ -151,12 +151,15 @@ struct lsblk {
 struct lsblk *lsblk;   /* global handler */
 
 #define NCOLS ARRAY_SIZE(infos)
-int columns[NCOLS];/* enabled columns */
-int ncolumns;          /* number of enabled columns */
+static int columns[NCOLS];/* enabled columns */
+static int ncolumns;           /* number of enabled columns */
 
 static int excludes[256];
 static size_t nexcludes;
 
+static int includes[256];
+static size_t nincludes;
+
 static struct libmnt_table *mtab, *swaps;
 static struct libmnt_cache *mntcache;
 
@@ -198,12 +201,30 @@ static int is_maj_excluded(int maj)
 
        assert(ARRAY_SIZE(excludes) > nexcludes);
 
+       if (!nexcludes)
+               return 0;       /* filter not enabled, device not exluded */
+
        for (i = 0; i < nexcludes; i++)
                if (excludes[i] == maj)
                        return 1;
        return 0;
 }
 
+static int is_maj_included(int maj)
+{
+       size_t i;
+
+       assert(ARRAY_SIZE(includes) > nincludes);
+
+       if (!nincludes)
+               return 1;       /* filter not enabled, device is included */
+
+       for (i = 0; i < nincludes; i++)
+               if (includes[i] == maj)
+                       return 1;
+       return 0;
+}
+
 /* array with IDs of enabled columns */
 static int get_column_id(int num)
 {
@@ -994,7 +1015,7 @@ static int iterate_block_devices(void)
                if (set_cxt(&cxt, NULL, NULL, d->d_name))
                        goto next;
 
-               if (!lsblk->all_devices && is_maj_excluded(cxt.maj))
+               if (is_maj_excluded(cxt.maj) || !is_maj_included(cxt.maj))
                        goto next;
 
                /* Skip devices in the middle of dependency tree. */
@@ -1101,6 +1122,28 @@ static void parse_excludes(const char *str)
        }
 }
 
+static void parse_includes(const char *str)
+{
+       while (str && *str) {
+               char *end = NULL;
+               unsigned long n;
+
+               errno = 0;
+               n = strtoul(str, &end, 10);
+
+               if (end == str || (errno != 0 && (n == ULONG_MAX || n == 0)))
+                       err(EXIT_FAILURE, _("failed to parse list '%s'"), str);
+               includes[nincludes++] = n;
+
+               if (nincludes == ARRAY_SIZE(includes))
+                       /* TRANSLATORS: The standard value for %d is 256. */
+                       errx(EXIT_FAILURE, _("the list of included devices is "
+                                       "too large (limit is %d devices)"),
+                                       (int)ARRAY_SIZE(includes));
+               str = end && *end ? end + 1 : NULL;
+       }
+}
+
 static void __attribute__((__noreturn__)) help(FILE *out)
 {
        size_t i;
@@ -1116,6 +1159,7 @@ static void __attribute__((__noreturn__)) help(FILE *out)
                " -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"
+               " -i, --include <list> show only devices with specified major numbers\n"
                " -f, --fs             output info about filesystems\n"
                " -h, --help           usage information (this)\n"
                " -i, --ascii          use ascii characters only\n"
@@ -1159,11 +1203,11 @@ int main(int argc, char *argv[])
                EXCL_LIST,
                EXCL_PAIRS,
 
-               EXCL_ALL,
-               EXCL_EXCLUDE
+               EXCL_EXCLUDE,
+               EXCL_INCLUDE,
        };
        int excl_rlP = EXCL_NONE;
-       int excl_ae = EXCL_NONE;
+       int excl_aeI = EXCL_NONE;
 
        static const struct option longopts[] = {
                { "all",        0, 0, 'a' },
@@ -1180,6 +1224,7 @@ int main(int argc, char *argv[])
                { "inverse",    0, 0, 's' },
                { "fs",         0, 0, 'f' },
                { "exclude",    1, 0, 'e' },
+               { "include",    1, 0, 'I' },
                { "topology",   0, 0, 't' },
                { "pairs",      0, 0, 'P' },
                { "version",    0, 0, 'V' },
@@ -1194,10 +1239,9 @@ int main(int argc, char *argv[])
        lsblk = &_ls;
        memset(lsblk, 0, sizeof(*lsblk));
 
-       while((c = getopt_long(argc, argv, "abdDe:fhlnmo:PirstV", longopts, NULL)) != -1) {
+       while((c = getopt_long(argc, argv, "abdDe:fhlnmo:PiI:rstV", longopts, NULL)) != -1) {
                switch(c) {
                case 'a':
-                       exclusive_option(&excl_ae, EXCL_ALL, "--{all,exclude}");
                        lsblk->all_devices = 1;
                        break;
                case 'b':
@@ -1214,7 +1258,7 @@ int main(int argc, char *argv[])
                        columns[ncolumns++] = COL_DZERO;
                        break;
                case 'e':
-                       exclusive_option(&excl_ae, EXCL_EXCLUDE, "--{all,exclude}");
+                       exclusive_option(&excl_aeI, EXCL_EXCLUDE, "--{exclude,include}");
                        parse_excludes(optarg);
                        break;
                case 'h':
@@ -1242,6 +1286,10 @@ int main(int argc, char *argv[])
                case 'i':
                        tt_flags |= TT_FL_ASCII;
                        break;
+               case 'I':
+                       exclusive_option(&excl_aeI, EXCL_INCLUDE, "--{exclude,include}");
+                       parse_includes(optarg);
+                       break;
                case 'r':
                        exclusive_option(&excl_rlP, EXCL_RAW, "--{raw,list,pairs}");
                        tt_flags &= ~TT_FL_TREE;        /* disable the default */
@@ -1296,7 +1344,7 @@ int main(int argc, char *argv[])
                columns[ncolumns++] = COL_TARGET;
        }
 
-       if (!nexcludes)
+       if (nexcludes == 0 && nincludes == 0)
                excludes[nexcludes++] = 1;      /* default: ignore RAM disks */
 
        mnt_init_debug(0);