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 4112ba36e2bfc0aa2710a7080726ebfe534cd73f..7d21567d5408198365a51ff9f5179bf5ad815533 100644 (file)
--- 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 d09d60c38bdc7c5fce1e606235a3492ea2e045a8..7328d0e30687da39ca49163593adc7cceb2256ca 100644 (file)
--- 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 bac443823b67669b5a6877abd5e087126eb32cc5..eff1f7774df2089c698659bd8908ad9a216be307 100644 (file)
--- 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 0605c355861d5f032d716d210db83070e61fee80..745cd115aaf87cafbc0126707bee56e4ea78b9e5 100644 (file)
--- 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 38e4c950d461b603387163e853d672e3574173f9..34ef408004011169fa9aed97e6b6e2d5dbaf93d3 100644 (file)
--- 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 6d2f433450df84c583a674942d4f7a3218b32a23..3e46af9ac5c3efacc21531c896d73613d23c97da 100644 (file)
--- 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