lsblk: add --filter

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

diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
index 57590da536ea0ebecf36f027a9ba55b0d16944ac..07b92fb0a7acf960bb7c88757cdc7f7192538738 100644 (file)
--- a/misc-utils/lsblk.c
+++ b/misc-utils/lsblk.c
@@ -242,6 +242,12 @@ static const struct colinfo infos[] = {
        [COL_ZONE_AMAX] = { "ZONE-AMAX", 10, SCOLS_FL_RIGHT, N_("maximum number of active zones"), COLTYPE_NUM },
 };
 
+/* "userdata" used by callback for libsmartcols filter */
+struct filler_data {
+       struct lsblk_device *dev;
+       struct lsblk_device *parent;
+};
+
 struct lsblk *lsblk;   /* global handler */
 
 /*
@@ -1209,6 +1215,50 @@ static char *device_get_data(
        return str;
 }
 
+static void device_fill_scols_cell(struct lsblk_device *dev,
+                                  struct lsblk_device *parent,
+                                  struct libscols_line *ln,
+                                  size_t colnum)
+{
+       struct libscols_cell *ce;
+       char *data;
+       size_t datasiz = 0;
+       int rc, id = get_column_id(colnum);
+
+       if (lsblk->sort_id != id)
+               data = device_get_data(dev, parent, id, NULL, &datasiz);
+       else {
+               uint64_t sortdata = (uint64_t) -1;
+
+               data = device_get_data(dev, parent, id, &sortdata, &datasiz);
+               if (data && sortdata != (uint64_t) -1)
+                       set_sortdata_u64(ln, colnum, sortdata);
+       }
+
+       if (!data)
+               return;
+       DBG(DEV, ul_debugobj(dev, " refer data[%zu]=\"%s\"", colnum, data));
+       ce = scols_line_get_cell(ln, colnum);
+       if (!ce)
+               return;
+       rc = datasiz ? scols_cell_refer_memory(ce, data, datasiz + 1)
+                    : scols_cell_refer_data(ce, data);
+       if (rc)
+               err(EXIT_FAILURE, _("failed to add output data"));
+}
+
+static int filter_filler_cb(
+                struct libscols_filter *fltr __attribute__((__unused__)),
+                struct libscols_line *ln,
+                size_t colnum,
+                void *userdata)
+{
+       struct filler_data *fid = (struct filler_data *) userdata;
+
+       device_fill_scols_cell(fid->dev, fid->parent, ln, colnum);
+       return 0;
+}
+
 /*
  * Adds data for all wanted columns about the device to the smartcols table
  */
@@ -1247,6 +1297,36 @@ static void device_to_scols(
 
        dev->is_printed = 1;
 
+       /* filter lines, smartcols filter can ask for data */
+       if (lsblk->scols_filter) {
+               int status = 0;
+               struct filler_data fid = {
+                       .dev = dev,
+                       .parent = parent
+               };
+
+               scols_filter_set_filler_cb(lsblk->scols_filter,
+                               filter_filler_cb, (void *) &fid);
+
+               if (scols_line_apply_filter(ln, lsblk->scols_filter, &status))
+                       err(EXIT_FAILURE, _("failed to apply filter"));
+               if (status == 0) {
+                       struct libscols_line *x = scols_line_get_parent(ln);
+
+                       if (x)
+                               scols_line_remove_child(x, ln);
+                       scols_table_remove_line(tab, ln);
+                       goto done;
+               }
+       }
+
+       /* read column specific data and set it to smartcols table line */
+       for (i = 0; i < ncolumns; i++) {
+               if (scols_line_is_filled(ln, i))
+                       continue;
+               device_fill_scols_cell(dev, parent, ln, i);
+       }
+
        if (link_group) {
                struct lsblk_device *p;
                struct libscols_line *gr = parent_line;
@@ -1268,35 +1348,6 @@ static void device_to_scols(
                scols_line_link_group(ln, gr, 0);
        }
 
-       /* read column specific data and set it to smartcols table line */
-       for (i = 0; i < ncolumns; i++) {
-               struct libscols_cell *ce;
-               char *data = NULL;
-               size_t datasiz = 0;
-               int rc, id = get_column_id(i);
-
-               if (lsblk->sort_id != id)
-                       data = device_get_data(dev, parent, id, NULL, &datasiz);
-               else {
-                       uint64_t sortdata = (uint64_t) -1;
-
-                       data = device_get_data(dev, parent, id, &sortdata, &datasiz);
-                       if (data && sortdata != (uint64_t) -1)
-                               set_sortdata_u64(ln, i, sortdata);
-               }
-
-               if (!data)
-                       continue;
-               DBG(DEV, ul_debugobj(dev, " refer data[%zu]=\"%s\"", i, data));
-               ce = scols_line_get_cell(ln, i);
-               if (!ce)
-                       continue;
-               rc = datasiz ? scols_cell_refer_memory(ce, data, datasiz + 1)
-                            : scols_cell_refer_data(ce, data);
-               if (rc)
-                       err(EXIT_FAILURE, _("failed to add output data"));
-       }
-
        dev->scols_line = ln;
 
        if (dev->npartitions == 0)
@@ -1310,7 +1361,7 @@ static void device_to_scols(
                device_to_scols(child, dev, tab, ln);
                DBG(DEV, ul_debugobj(dev, "%s <- child done", dev->name));
        }
-
+done:
        /* Let's be careful with number of open files */
        ul_path_close_dirfd(dev->sysfs);
 }
@@ -1997,6 +2048,50 @@ static void devtree_set_dedupkeys(struct lsblk_devtree *tr, int id)
                device_set_dedupkey(dev, NULL, id);
 }
 
+
+static struct libscols_filter *init_scols_filter(
+                       struct libscols_table *tb,
+                       const char *query)
+{
+       struct libscols_filter *f;
+       struct libscols_iter *itr;
+       const char *name = NULL;
+
+       f = scols_new_filter(NULL);
+       if (!f)
+               err(EXIT_FAILURE, _("failed to allocate filter"));
+       if (scols_filter_parse_string(f, query) != 0)
+               errx(EXIT_FAILURE, _("failed to parse \"%s\": %s"), query,
+                               scols_filter_get_errmsg(f));
+
+       itr = scols_new_iter(SCOLS_ITER_FORWARD);
+       if (!itr)
+               err(EXIT_FAILURE, _("failed to allocate iterator"));
+
+       while (scols_filter_next_holder(f, itr, &name, 0) == 0) {
+               struct libscols_column *col = scols_table_get_column_by_name(tb, name);
+
+               if (!col) {
+                       int id = column_name_to_id(name, strlen(name));
+                       const struct colinfo *ci = id >= 0 ? &infos[id] : NULL;
+
+                       if (!ci)
+                               goto fail;
+                       add_column(id);
+                       col = scols_table_new_column(lsblk->table, ci->name,
+                                                    ci->whint, SCOLS_FL_HIDDEN);
+                       if (!col)
+                               err(EXIT_FAILURE,_("failed to allocate output column"));
+               }
+               scols_filter_assign_column(f, itr, name, col);
+       }
+
+       scols_free_iter(itr);
+       return f;
+fail:
+       errx(EXIT_FAILURE, _("failed to initialize filter"));
+}
+
 static void __attribute__((__noreturn__)) usage(void)
 {
        FILE *out = stdout;
@@ -2017,6 +2112,7 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_(" -M, --merge          group parents of sub-trees (usable for RAIDs, Multi-path)\n"), out);
        fputs(_(" -O, --output-all     output all columns\n"), out);
        fputs(_(" -P, --pairs          use key=\"value\" output format\n"), out);
+       fputs(_(" -Q, --filter <query> restrict output\n"), out);
        fputs(_(" -S, --scsi           output info about SCSI devices\n"), out);
        fputs(_(" -N, --nvme           output info about NVMe devices\n"), out);
        fputs(_(" -v, --virtio         output info about virtio devices\n"), out);
@@ -2070,7 +2166,7 @@ int main(int argc, char *argv[])
        };
        struct lsblk_devtree *tr = NULL;
        int c, status = EXIT_FAILURE;
-       char *outarg = NULL;
+       char *outarg = NULL, *f_query = NULL;
        size_t i;
        unsigned int width = 0;
        int force_tree = 0, has_tree_col = 0;
@@ -2091,6 +2187,7 @@ int main(int argc, char *argv[])
                { "json",       no_argument,       NULL, 'J' },
                { "output",     required_argument, NULL, 'o' },
                { "output-all", no_argument,       NULL, 'O' },
+               { "filter",     required_argument, NULL, 'Q' },
                { "merge",      no_argument,       NULL, 'M' },
                { "perms",      no_argument,       NULL, 'm' },
                { "noheadings", no_argument,       NULL, 'n' },
@@ -2140,7 +2237,7 @@ int main(int argc, char *argv[])
        lsblk_init_debug();
 
        while((c = getopt_long(argc, argv,
-                               "AabdDzE:e:fhJlNnMmo:OpPiI:rstVvST::w:x:y",
+                               "AabdDzE:e:fhJlNnMmo:OpPQ:iI:rstVvST::w:x:y",
                                longopts, NULL)) != -1) {
 
                err_exclusive_options(c, longopts, excl, excl_st);
@@ -2204,6 +2301,10 @@ int main(int argc, char *argv[])
                        lsblk->flags |= LSBLK_EXPORT;
                        lsblk->flags &= ~LSBLK_TREE;    /* disable the default */
                        break;
+               case 'Q':
+                       f_query = optarg;
+                       lsblk->flags &= ~LSBLK_TREE; /* disable the default */
+                       break;
                case 'y':
                        lsblk->flags |= LSBLK_SHELLVAR;
                        break;
@@ -2454,6 +2555,9 @@ int main(int argc, char *argv[])
                }
        }
 
+       if (f_query)
+               lsblk->scols_filter = init_scols_filter(lsblk->table, f_query);
+
        tr = lsblk_new_devtree();
        if (!tr)
                err(EXIT_FAILURE, _("failed to allocate device tree"));
@@ -2497,6 +2601,7 @@ leave:
                unref_sortdata(lsblk->table);
 
        scols_unref_table(lsblk->table);
+       scols_unref_filter(lsblk->scols_filter);
 
        lsblk_mnt_deinit();
        lsblk_properties_deinit();

diff --git a/misc-utils/lsblk.h b/misc-utils/lsblk.h
index a437c0612ab768e3a449459c1325d39bd5dd478e..4310ac8594a490f6417fd46e1f0be2b4fcd37ca4 100644 (file)
--- a/misc-utils/lsblk.h
+++ b/misc-utils/lsblk.h
@@ -41,6 +41,7 @@ struct lsblk {
 
        int dedup_id;
 
+       struct libscols_filter *scols_filter;
 
        const char *sysroot;
        int flags;                      /* LSBLK_* */