libblkid: allows more probing methods for topology chain

This patch moves the current topology code to the separate sysfs.c
file.

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

1 files changed, 39 insertions, 138 deletions

diff --git a/shlibs/blkid/src/topology/topology.c b/shlibs/blkid/src/topology/topology.c
index b4240543..26930cfa 100644
--- a/shlibs/blkid/src/topology/topology.c
+++ b/shlibs/blkid/src/topology/topology.c
@@ -5,25 +5,13 @@
  *
  * This file may be redistributed under the terms of the
  * GNU Lesser General Public License.
- *
- * NOTE: this chain supports one probing method only, so it's implemented
- *       without array of probing functions (idinfos array).
- *
- *       This chain does not support probing functions filtering. The chain
- *       could be enable or disabled only.
  */
 
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#include <stddef.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <errno.h>
 
-#include "blkdev.h"
-#include "blkidP.h"
+#include "topology.h"
 
 /**
  * SECTION:topology
@@ -55,26 +43,28 @@ static int topology_probe(blkid_probe pr, struct blkid_chain *chn);
 static void topology_free(blkid_probe pr, void *data);
 
 /*
+ * Topology chain probing functions
+ */
+static const struct blkid_idinfo *idinfos[] =
+{
+	&sysfs_tp_idinfo
+};
+
+
+/*
  * Driver definition
  */
 const struct blkid_chaindrv topology_drv = {
 	.id           = BLKID_CHAIN_TOPLGY,
 	.name         = "topology",
 	.dflt_enabled = FALSE,
+	.idinfos      = idinfos,
+	.nidinfos     = ARRAY_SIZE(idinfos),
 	.probe        = topology_probe,
 	.safeprobe    = topology_probe,
 	.free_data    = topology_free
 };
 
-/*
- * Binary interface
- */
-struct blkid_struct_topology {
-	unsigned long	alignment_offset;
-	unsigned long	minimum_io_size;
-	unsigned long	optimal_io_size;
-};
-
 /**
  * blkid_probe_enable_topology:
  * @pr: probe
@@ -110,109 +100,17 @@ blkid_topology blkid_probe_get_topology(blkid_probe pr)
 			&pr->chains[BLKID_CHAIN_TOPLGY]);
 }
 
-static unsigned long
-dev_topology_attribute(const char *attribute, dev_t dev, dev_t *primary)
-{
-	const char *sysfs_fmt_str = "/sys/dev/block/%d:%d/%s";
-	char path[PATH_MAX];
-	int len;
-	FILE *fp = NULL;
-	struct stat info;
-	unsigned long result = 0UL;
-
-	len = snprintf(path, sizeof(path), sysfs_fmt_str,
-			major(dev), minor(dev), attribute);
-	if (len < 0 || len + 1 > sizeof(path))
-		goto err;
-
-	/*
-	 * check if the desired sysfs attribute exists
-	 * - if not: either the kernel doesn't have topology support or the
-	 *   device could be a partition
-	 */
-	if (stat(path, &info) < 0) {
-		if (!*primary &&
-		    blkid_devno_to_wholedisk(dev, NULL, 0, primary))
-			goto err;
-
-		/* get attribute from partition's primary device */
-		len = snprintf(path, sizeof(path), sysfs_fmt_str,
-				major(*primary), minor(*primary), attribute);
-		if (len < 0 || len + 1 > sizeof(path))
-			goto err;
-	}
-
-	fp = fopen(path, "r");
-	if (!fp) {
-		DBG(DEBUG_LOWPROBE, printf(
-			"topology: %s: fopen failed, errno=%d\n", path, errno));
-		goto err;
-	}
-
-	if (fscanf(fp, "%lu", &result) != 1) {
-		DBG(DEBUG_LOWPROBE, printf(
-			"topology: %s: unexpected file format\n", path));
-		goto err;
-	}
-
-	fclose(fp);
-
-	DBG(DEBUG_LOWPROBE,
-		printf("topology: attribute %s = %lu (sectors)\n", attribute, result));
-
-	return result;
-err:
-	if (fp)
-		fclose(fp);
-	DBG(DEBUG_LOWPROBE,
-		printf("topology: failed to read %s attribute\n", attribute));
-	return 0;
-}
-
-/*
- * Topology values
- */
-static struct topology_val {
-	const char *val_name;		/* NAME=value */
-	const char *sysfs_name;		/* /sys/dev/block/<maj>:<min>/NAME */
-	const size_t bin_offset;	/* blkid_struct_topology member */
-} topology_vals[] = {
-	{ "ALIGNMENT_OFFSET", "alignment_offset",
-		offsetof(struct blkid_struct_topology, alignment_offset) },
-	{ "MINIMUM_IO_SIZE", "queue/minimum_io_size",
-		offsetof(struct blkid_struct_topology, minimum_io_size) },
-	{"OPTIMAL_IO_SIZE", "queue/optimal_io_size",
-		offsetof(struct blkid_struct_topology, optimal_io_size) }
-};
-
-static int topology_set_value(blkid_probe pr, struct blkid_chain *chn,
-				struct topology_val *val, unsigned long data)
-{
-	if (chn->binary) {
-		unsigned long *v =
-			(unsigned long *) (chn->data + val->bin_offset);
-		*v = data;
-		return 0;
-	}
-	return blkid_probe_sprintf_value(pr, val->val_name, "%llu", data);
-}
-
 /*
  * The blkid_do_probe() backend.
  */
 static int topology_probe(blkid_probe pr, struct blkid_chain *chn)
 {
-	dev_t dev, pri_dev = 0;
-	int i, rc = 0, count = 0;
+	int i = 0;
 
-	if (!pr)
+	if (!pr || chn->idx < -1)
+		return -1;
+	if (chn->idx < -1)
 		return -1;
-
-	blkid_probe_chain_reset_vals(pr, chn);
-
-	dev = blkid_probe_get_devno(pr);
-	if (!dev)
-		return 1;	/* no result */
 
 	if (chn->binary) {
 		DBG(DEBUG_LOWPROBE, printf("initialize topology binary data\n"));
@@ -229,33 +127,36 @@ static int topology_probe(blkid_probe pr, struct blkid_chain *chn)
 		}
 	}
 
-	DBG(DEBUG_LOWPROBE, printf("--> starting probing loop [TOPOLOGY]\n"));
+	blkid_probe_chain_reset_vals(pr, chn);
+
+	DBG(DEBUG_LOWPROBE,
+		printf("--> starting probing loop [TOPOLOGY idx=%d]\n",
+		chn->idx));
 
-	for (i = 0; i < ARRAY_SIZE(topology_vals); i++) {
-		struct topology_val *val = &topology_vals[i];
-		unsigned long data;
+	i = chn->idx + 1;
 
-		/*
-		 * Don't bother reporting any of the topology information
-		 * if it's zero.
-		 */
-		data = dev_topology_attribute(val->sysfs_name, dev, &pri_dev);
-		if (!data)
-			continue;
+	for ( ; i < ARRAY_SIZE(idinfos); i++) {
+		const struct blkid_idinfo *id = idinfos[i];
 
-		rc = topology_set_value(pr, chn, val, data);
-		if (rc)
-			break;	/* error */
-		count++;
-	}
+		chn->idx = i;
 
+		if (id->probefunc) {
+			DBG(DEBUG_LOWPROBE, printf(
+				"%s: call probefunc()\n", id->name));
+			if (id->probefunc(pr, NULL) != 0)
+				continue;
+		}
 
-	if (rc == 0 && count == 0)
-		rc = 1;			/* no result */
+		DBG(DEBUG_LOWPROBE,
+			printf("<-- leaving probing loop (type=%s) [TOPOLOGY idx=%d]\n",
+			id->name, chn->idx));
+		return 0;
+	}
 
 	DBG(DEBUG_LOWPROBE,
-		printf("<-- leaving probing loop [TOPOLOGY, rc=%d]\n", rc));
-	return rc;
+		printf("<-- leaving probing loop (failed) [TOPOLOGY idx=%d]\n",
+		chn->idx));
+	return 1;
 }
 
 static void topology_free(blkid_probe pr, void *data)