kernel: disk: Add DISK_IO_QUERY op to disk engine

This commit introduces the DISK_IO_QUERY opcode to the disk engine so
that a user application may query specific devices.

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 13 insertions, 0 deletions

diff --git a/sys/include/sys/disk.h b/sys/include/sys/disk.h
index a277797..4ad068b 100644
--- a/sys/include/sys/disk.h
+++ b/sys/include/sys/disk.h
@@ -78,6 +78,7 @@ _Static_assert((V_BSIZE & 1) == 0, "V_BSIZE must be a power of two");
 /* Valid disk operations */
 #define DISK_IO_READ    0x00    /* Read data from the disk */
 #define DISK_IO_WRITE   0x01    /* Write data to disk */
+#define DISK_IO_QUERY   0x02    /* Query disk information */
 
 /*
  * A disk identifier is a zero-based index into
diff --git a/sys/kern/disk_engine.c b/sys/kern/disk_engine.c
index a49c15f..1061165 100644
--- a/sys/kern/disk_engine.c
+++ b/sys/kern/disk_engine.c
@@ -172,6 +172,18 @@ disk_mux_io(diskid_t id, diskop_t opcode, struct disk_param *u_param)
             param.size
         );
         break;
+    case DISK_IO_QUERY:
+        retval = disk_query(
+            id,
+            param.buf
+        );
+
+        /* Write back info to user program */
+        error = copyout(param.buf, param.u_buf, param.size);
+        if (error < 0) {
+            retval = error;
+        }
+        break;
     }
 
     disk_param_free(&param);