libblockdriver: allow for not handling partitions

Each block driver now gets to specify whether it is a disk block
driver, which implies it wants the library to handle getting and
setting partitions for it.

common/include/minix/blockdriver.h

@@ -5,8 +5,15 @@
 
 typedef int thread_id_t;
 
+/* Types supported for the 'type' field of struct blockdriver. */
+typedef enum {
+  BLOCKDRIVER_TYPE_DISK,		/* handle partition requests */
+  BLOCKDRIVER_TYPE_OTHER		/* do not handle partition requests */
+} blockdriver_type_t;
+
 /* Entry points into the device dependent code of block drivers. */
 struct blockdriver {
+  blockdriver_type_t bdr_type;
   _PROTOTYPE( int (*bdr_open), (dev_t minor, int access) );
   _PROTOTYPE( int (*bdr_close), (dev_t minor) );
   _PROTOTYPE( ssize_t (*bdr_transfer), (dev_t minor, int do_write, u64_t pos,

drivers/ahci/ahci.c

@@ -208,6 +208,7 @@ PRIVATE struct port_state *ahci_get_port(dev_t minor);
 
 /* AHCI driver table. */
 PRIVATE struct blockdriver ahci_dtab = {
+	BLOCKDRIVER_TYPE_DISK,
 	ahci_open,
 	ahci_close,
 	ahci_transfer,

drivers/at_wini/at_wini.c

@@ -200,6 +200,7 @@ FORWARD _PROTOTYPE( int at_in, (int line, u32_t port, unsigned long *value,
 
 /* Entry points to this driver. */
 PRIVATE struct blockdriver w_dtab = {
+  BLOCKDRIVER_TYPE_DISK,/* handle partition requests */
   w_do_open,		/* open or mount request, initialize device */
   w_do_close,		/* release device */
   w_transfer,		/* do the I/O */

drivers/bios_wini/bios_wini.c

@@ -70,6 +70,7 @@ FORWARD _PROTOTYPE( int w_ioctl, (dev_t minor, unsigned int request,
 
 /* Entry points to this driver. */
 PRIVATE struct blockdriver w_dtab = {
+  BLOCKDRIVER_TYPE_DISK,	/* handle partition requests */
   w_do_open,	/* open or mount request, initialize device */
   w_do_close,	/* release device */
   w_transfer,	/* do the I/O */

drivers/floppy/floppy.c

@@ -267,6 +267,7 @@ FORWARD _PROTOTYPE( void f_geometry, (dev_t minor,
 
 /* Entry points to this driver. */
 PRIVATE struct blockdriver f_dtab = {
+  BLOCKDRIVER_TYPE_DISK,	/* handle partition requests */
   f_do_open,	/* open or mount request, sense type of diskette */
   f_do_close,	/* nothing on a close */
   f_transfer,	/* do the I/O */

drivers/memory/memory.c

@@ -76,6 +76,7 @@ PRIVATE struct chardriver m_cdtab = {
 
 /* Entry points to the BLOCK part of this driver. */
 PRIVATE struct blockdriver m_bdtab = {
+  BLOCKDRIVER_TYPE_DISK,/* handle partition requests */
   m_block_open,		/* open or mount */
   m_block_close,	/* nothing on a close */
   m_block_transfer,	/* do the I/O */

lib/libblockdriver/driver.c

@@ -248,39 +248,20 @@ PRIVATE int do_vrdwt(struct blockdriver *bdp, message *mp, thread_id_t id)
 }
 
 /*===========================================================================*
- *				do_ioctl				     *
+ *				do_dioctl				     *
  *===========================================================================*/
-PRIVATE int do_ioctl(struct blockdriver *bdp, message *mp)
+PRIVATE int do_dioctl(struct blockdriver *bdp, dev_t minor,
+  unsigned int request, endpoint_t endpt, cp_grant_id_t grant)
 {
-/* Carry out an I/O control request. For now, we handle setting/getting
- * partitions here, forward block trace control requests to the tracing module,
- * and let the driver handle any other requests. In the future, a stricter
- * separation between block and disk I/O controls may become desirable, but we
- * do not have any non-"disk" block drivers at this time.
- */
+/* Carry out a disk-specific I/O control request. */
   struct device *dv;
   struct partition entry;
-  unsigned int request;
-  cp_grant_id_t grant;
-  dev_t minor;
-  int r;
-
-  minor = mp->BDEV_MINOR;
-  request = mp->BDEV_REQUEST;
-  grant = mp->BDEV_GRANT;
+  int r = EINVAL;
 
   switch (request) {
-  case BIOCTRACEBUF:
-  case BIOCTRACECTL:
-  case BIOCTRACEGET:
-	/* Block trace control. */
-	r = trace_ctl(minor, request, mp->m_source, grant);
-
-	break;
-
   case DIOCSETP:
 	/* Copy just this one partition table entry. */
-	r = sys_safecopyfrom(mp->m_source, grant, 0, (vir_bytes) &entry,
+	r = sys_safecopyfrom(endpt, grant, 0, (vir_bytes) &entry,
 		sizeof(entry), D);
 	if (r != OK)
 		return r;
@@ -307,11 +288,53 @@ PRIVATE int do_ioctl(struct blockdriver *bdp, message *mp)
 		entry.sectors = 32;
 	}
 
-	r = sys_safecopyto(mp->m_source, grant, 0, (vir_bytes) &entry,
-		sizeof(entry), D);
+	r = sys_safecopyto(endpt, grant, 0, (vir_bytes) &entry, sizeof(entry),
+		D);
+
+	break;
+  }
+
+  return r;
+}
+
+/*===========================================================================*
+ *				do_ioctl				     *
+ *===========================================================================*/
+PRIVATE int do_ioctl(struct blockdriver *bdp, message *mp)
+{
+/* Carry out an I/O control request. We forward block trace control requests
+ * to the tracing module, and handle setting/getting partitions when the driver
+ * has specified that it is a disk driver.
+ */
+  dev_t minor;
+  unsigned int request;
+  cp_grant_id_t grant;
+  int r;
+
+  minor = mp->BDEV_MINOR;
+  request = mp->BDEV_REQUEST;
+  grant = mp->BDEV_GRANT;
+
+  switch (request) {
+  case BIOCTRACEBUF:
+  case BIOCTRACECTL:
+  case BIOCTRACEGET:
+	/* Block trace control. */
+	r = trace_ctl(minor, request, mp->m_source, grant);
 
 	break;
 
+  case DIOCSETP:
+  case DIOCGETP:
+	/* Handle disk-specific IOCTLs only for disk-type drivers. */
+	if (bdp->bdr_type == BLOCKDRIVER_TYPE_DISK) {
+		/* Disk partition control. */
+		r = do_dioctl(bdp, minor, request, mp->m_source, grant);
+
+		break;
+	}
+
+	/* fall-through */
   default:
 	if (bdp->bdr_ioctl)
 		r = (*bdp->bdr_ioctl)(minor, request, mp->m_source, grant);