libblock: Change bdbuf API

The functions
 o rtems_bdbuf_get(),
 o rtems_bdbuf_read(),
 o rtems_bdbuf_syncdev(), and
 o rtems_bdbuf_purge_dev(),
use now the disk device instead of the device identifier.  This makes
bdbuf independent of rtems_disk_obtain() and rtems_disk_release().  It
is the responsiblity of the file system to obtain the disk device.  This
also reduces the overhead to get a buffer.

The key for the AVL tree uses now the disk device instead of the device
identifier.  The pointer is interpreted as an unsigned integer.  This
reduces the memory overhead and makes the comparison operation a bit
faster.

Removed function rtems_bdbuf_purge_major().  This function was too
destructive and could have unpredictable side effects.

1 files changed, 42 insertions, 23 deletions

diff --git a/cpukit/libblock/src/bdpart-read.c b/cpukit/libblock/src/bdpart-read.c
index 3560dbd3a3..4604e1080b 100644
--- a/cpukit/libblock/src/bdpart-read.c
+++ b/cpukit/libblock/src/bdpart-read.c
@@ -23,6 +23,9 @@
 #include "config.h"
 #endif
 
+#include <sys/stat.h>
+#include <fcntl.h>
+
 #include <rtems.h>
 #include <rtems/bdbuf.h>
 #include <rtems/bdpart.h>
@@ -64,48 +67,59 @@ bool rtems_bdpart_to_mbr_partition_type(
  */
 rtems_status_code rtems_bdpart_get_disk_data(
   const char *disk_name,
-  dev_t *disk,
+  int *fd_ptr,
+  const rtems_disk_device **dd_ptr,
   rtems_blkdev_bnum *disk_end
 )
 {
   rtems_status_code sc = RTEMS_SUCCESSFUL;
   int rv = 0;
+  int fd = -1;
+  const rtems_disk_device *dd = NULL;
   rtems_blkdev_bnum disk_begin = 0;
   rtems_blkdev_bnum block_size = 0;
-  rtems_disk_device *dd = NULL;
-  struct stat st;
+
+  /* Open device file */
+  fd = open( disk_name, O_RDWR);
+  if (fd < 0) {
+    sc = RTEMS_INVALID_NAME;
+    goto error;
+  }
 
   /* Get disk handle */
-  rv = stat( disk_name, &st);
+  rv = rtems_disk_fd_get_disk_device( fd, &dd);
   if (rv != 0) {
-    return RTEMS_INVALID_NAME;
+    sc = RTEMS_INVALID_NAME;
+    goto error;
   }
-  *disk = st.st_rdev;
 
   /* Get disk begin, end and block size */
-  dd = rtems_disk_obtain( *disk);
-  if (dd == NULL) {
-    return RTEMS_INVALID_NAME;
-  }
   disk_begin = dd->start;
   *disk_end = dd->size;
   block_size = dd->block_size;
-  sc = rtems_disk_release( dd);
-  if (sc != RTEMS_SUCCESSFUL) {
-    return sc;
-  }
 
   /* Check block size */
   if (block_size < RTEMS_BDPART_BLOCK_SIZE) {
-    return RTEMS_IO_ERROR;
+    sc = RTEMS_IO_ERROR;
+    goto error;
   }
 
   /* Check that we have do not have a logical disk */
   if (disk_begin != 0) {
-    return RTEMS_IO_ERROR;
+    sc = RTEMS_IO_ERROR;
+    goto error;
   }
 
-  return RTEMS_SUCCESSFUL;
+error:
+
+  if (sc == RTEMS_SUCCESSFUL && fd_ptr != NULL && dd_ptr != NULL) {
+    *fd_ptr = fd;
+    *dd_ptr = dd;
+  } else {
+    close( fd);
+  }
+
+  return sc;
 }
 
 static bool rtems_bdpart_is_valid_record( const uint8_t *data)
@@ -171,7 +185,7 @@ static rtems_status_code rtems_bdpart_read_mbr_partition(
 }
 
 static rtems_status_code rtems_bdpart_read_record(
-  dev_t disk,
+  const rtems_disk_device *dd,
   rtems_blkdev_bnum index,
   rtems_bdbuf_buffer **block
 )
@@ -187,7 +201,7 @@ static rtems_status_code rtems_bdpart_read_record(
   }
 
   /* Read the record block */
-  sc = rtems_bdbuf_read( disk, index, block);
+  sc = rtems_bdbuf_read( dd, index, block);
   if (sc != RTEMS_SUCCESSFUL) {
     return sc;
   }
@@ -220,9 +234,10 @@ rtems_status_code rtems_bdpart_read(
   rtems_blkdev_bnum ep_begin = 0; /* Extended partition begin */
   rtems_blkdev_bnum ebr = 0; /* Extended boot record block index */
   rtems_blkdev_bnum disk_end = 0;
-  dev_t disk = 0;
   size_t i = 0;
   const uint8_t *data = NULL;
+  int fd = -1;
+  const rtems_disk_device *dd = NULL;
 
   /* Check parameter */
   if (format == NULL || pt == NULL || count == NULL) {
@@ -233,13 +248,13 @@ rtems_status_code rtems_bdpart_read(
   *count = 0;
 
   /* Get disk data */
-  sc = rtems_bdpart_get_disk_data( disk_name, &disk, &disk_end);
+  sc = rtems_bdpart_get_disk_data( disk_name, &fd, &dd, &disk_end);
   if (sc != RTEMS_SUCCESSFUL) {
     return sc;
   }
 
   /* Read MBR */
-  sc = rtems_bdpart_read_record( disk, 0, &block);
+  sc = rtems_bdpart_read_record( dd, 0, &block);
   if (sc != RTEMS_SUCCESSFUL) {
     esc = sc;
     goto cleanup;
@@ -283,7 +298,7 @@ rtems_status_code rtems_bdpart_read(
     rtems_blkdev_bnum tmp = 0;
 
     /* Read EBR */
-    sc = rtems_bdpart_read_record( disk, ebr, &block);
+    sc = rtems_bdpart_read_record( dd, ebr, &block);
     if (sc != RTEMS_SUCCESSFUL) {
       esc = sc;
       goto cleanup;
@@ -340,6 +355,10 @@ rtems_status_code rtems_bdpart_read(
 
 cleanup:
 
+  if (fd >= 0) {
+    close( fd);
+  }
+
   if (block != NULL) {
     rtems_bdbuf_release( block);
   }