From: Anthony Iliopoulos <ailiop@suse.com>
Date: Tue, 5 May 2020 14:31:45 +0000 (+0200)
Subject: libblkid: add dax capability detection in topology probing
X-Git-Tag: v2.36-rc1~112
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=17c57e250991b47f1882dfe74386aab56076607f;p=thirdparty%2Futil-linux.git

libblkid: add dax capability detection in topology probing

The dax (direct access) blockdev capability is exposed via sysfs, add it
to the list of topology values to be obtained while probing.

Expose blkid_topology_get_dax() symbol that programs can link against
for querying the capability.

Reorder the idinfos array to give precedence to the sysfs over ioctl so
that the dax probe has a chance to be executed, as there is no ioctl
interface for it.

Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
---

diff --git a/libblkid/samples/topology.c b/libblkid/samples/topology.c
index 4112ba36e2..7d21567d54 100644
--- a/libblkid/samples/topology.c
+++ b/libblkid/samples/topology.c
@@ -51,6 +51,8 @@ int main(int argc, char *argv[])
 				blkid_topology_get_logical_sector_size(tp));
 		printf("\tphysical sector size : %lu\n",
 				blkid_topology_get_physical_sector_size(tp));
+		printf("\tdax support          : %lu\n",
+				blkid_topology_get_dax(tp));
 	}
 
 	/*
diff --git a/libblkid/src/blkid.h.in b/libblkid/src/blkid.h.in
index d09d60c38b..7328d0e306 100644
--- a/libblkid/src/blkid.h.in
+++ b/libblkid/src/blkid.h.in
@@ -325,6 +325,8 @@ extern unsigned long blkid_topology_get_logical_sector_size(blkid_topology tp)
 			__ul_attribute__((nonnull));
 extern unsigned long blkid_topology_get_physical_sector_size(blkid_topology tp)
 			__ul_attribute__((nonnull));
+extern unsigned long blkid_topology_get_dax(blkid_topology tp)
+			__ul_attribute__((nonnull));
 
 /*
  * partitions probing
diff --git a/libblkid/src/libblkid.sym b/libblkid/src/libblkid.sym
index bac443823b..eff1f7774d 100644
--- a/libblkid/src/libblkid.sym
+++ b/libblkid/src/libblkid.sym
@@ -174,3 +174,7 @@ BLKID_2_31 {
 	blkid_probe_reset_buffers;
 	blkid_probe_hide_range;
 } BLKID_2.30;
+
+BLKID_2_35 {
+	blkid_topology_get_dax;
+} BLKID_2_31;
diff --git a/libblkid/src/topology/sysfs.c b/libblkid/src/topology/sysfs.c
index 0605c35586..745cd115aa 100644
--- a/libblkid/src/topology/sysfs.c
+++ b/libblkid/src/topology/sysfs.c
@@ -37,6 +37,7 @@ static struct topology_val {
 	{ "queue/minimum_io_size", blkid_topology_set_minimum_io_size },
 	{ "queue/optimal_io_size", blkid_topology_set_optimal_io_size },
 	{ "queue/physical_block_size", blkid_topology_set_physical_sector_size },
+	{ "queue/dax", blkid_topology_set_dax },
 };
 
 static int probe_sysfs_tp(blkid_probe pr,
diff --git a/libblkid/src/topology/topology.c b/libblkid/src/topology/topology.c
index 38e4c950d4..34ef408004 100644
--- a/libblkid/src/topology/topology.c
+++ b/libblkid/src/topology/topology.c
@@ -67,6 +67,7 @@ struct blkid_struct_topology {
 	unsigned long	optimal_io_size;
 	unsigned long	logical_sector_size;
 	unsigned long	physical_sector_size;
+	unsigned long   dax;
 };
 
 /*
@@ -75,8 +76,8 @@ struct blkid_struct_topology {
 static const struct blkid_idinfo *idinfos[] =
 {
 #ifdef __linux__
-	&ioctl_tp_idinfo,
 	&sysfs_tp_idinfo,
+	&ioctl_tp_idinfo,
 	&md_tp_idinfo,
 	&dm_tp_idinfo,
 	&lvm_tp_idinfo,
@@ -303,6 +304,14 @@ int blkid_topology_set_physical_sector_size(blkid_probe pr, unsigned long val)
 			val);
 }
 
+int blkid_topology_set_dax(blkid_probe pr, unsigned long val)
+{
+	return topology_set_value(pr,
+			"DAX",
+			offsetof(struct blkid_struct_topology, dax),
+			val);
+}
+
 /**
  * blkid_topology_get_alignment_offset:
  * @tp: topology
@@ -358,3 +367,13 @@ unsigned long blkid_topology_get_physical_sector_size(blkid_topology tp)
 	return tp->physical_sector_size;
 }
 
+/**
+ * blkid_topology_get_dax
+ * @tp: topology
+ *
+ * Returns: 1 if dax is supported, 0 otherwise.
+ */
+unsigned long blkid_topology_get_dax(blkid_topology tp)
+{
+	return tp->dax;
+}
diff --git a/libblkid/src/topology/topology.h b/libblkid/src/topology/topology.h
index 6d2f433450..3e46af9ac5 100644
--- a/libblkid/src/topology/topology.h
+++ b/libblkid/src/topology/topology.h
@@ -7,6 +7,7 @@ extern int blkid_topology_set_alignment_offset(blkid_probe pr, int val);
 extern int blkid_topology_set_minimum_io_size(blkid_probe pr, unsigned long val);
 extern int blkid_topology_set_optimal_io_size(blkid_probe pr, unsigned long val);
 extern int blkid_topology_set_physical_sector_size(blkid_probe pr, unsigned long val);
+extern int blkid_topology_set_dax(blkid_probe pr, unsigned long val);
 
 /*
  * topology probers