bdbuf.c File Reference

Block device buffer management. More...

#include <limits.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <pthread.h>
#include <rtems.h>
#include <rtems/error.h>
#include "rtems/bdbuf.h"

Include dependency graph for bdbuf.c:

Data Structures
struct	rtems_bdbuf_swapout_transfer
	A swapout transfer transaction data. More...
struct	rtems_bdbuf_swapout_worker
	Swapout worker thread. More...
struct	rtems_bdbuf_waiters
	Buffer waiters synchronization. More...
struct	rtems_bdbuf_cache
	The BD buffer cache. More...

Macros
#define	RTEMS_BDBUF_TRACE   0
	Set to 1 to enable debug tracing.
#define	BDBUF_INVALID_DEV   NULL
#define	bdbuf_config   rtems_bdbuf_configuration
#define	RTEMS_BDBUF_SWAPOUT_SYNC   RTEMS_EVENT_2
	The events used in this code. More...
#define	RTEMS_BDBUF_READ_AHEAD_WAKE_UP   RTEMS_EVENT_1
#define	RTEMS_BDBUF_CACHE_LOCK_ATTRIBS
	Lock semaphore attributes. More...
#define	RTEMS_BDBUF_CACHE_WAITER_ATTRIBS
	Waiter semaphore attributes. More...
#define	RTEMS_BDBUF_WAIT_TIMEOUT   RTEMS_NO_TIMEOUT
	Waiter timeout. More...
#define	rtems_bdbuf_tracer   (0)
#define	rtems_bdbuf_show_usage()   ((void) 0)
#define	rtems_bdbuf_show_users(_w, _b)   ((void) 0)
#define	RTEMS_BDBUF_AVL_MAX_HEIGHT   (32)
	The default maximum height of 32 allows for AVL trees having between 5,704,880 and 4,294,967,295 nodes, depending on order of insertion. More...
#define	bdbuf_alloc(size)   __builtin_alloca (size)

Typedefs
typedef struct rtems_bdbuf_swapout_transfer	rtems_bdbuf_swapout_transfer
	A swapout transfer transaction data. More...
typedef struct rtems_bdbuf_swapout_worker	rtems_bdbuf_swapout_worker
	Swapout worker thread. More...
typedef rtems_id	rtems_bdbuf_lock_type
typedef struct rtems_bdbuf_waiters	rtems_bdbuf_waiters
	Buffer waiters synchronization.
typedef struct rtems_bdbuf_cache	rtems_bdbuf_cache
	The BD buffer cache.

Enumerations
enum	rtems_bdbuf_fatal_code {   RTEMS_BDBUF_FATAL_CACHE_LOCK, RTEMS_BDBUF_FATAL_CACHE_UNLOCK, RTEMS_BDBUF_FATAL_CACHE_WAIT_2, RTEMS_BDBUF_FATAL_CACHE_WAIT_TO,   RTEMS_BDBUF_FATAL_CACHE_WAKE, RTEMS_BDBUF_FATAL_PREEMPT_DIS, RTEMS_BDBUF_FATAL_PREEMPT_RST, RTEMS_BDBUF_FATAL_RA_WAKE_UP,   RTEMS_BDBUF_FATAL_RECYCLE, RTEMS_BDBUF_FATAL_SO_WAKE_1, RTEMS_BDBUF_FATAL_SO_WAKE_2, RTEMS_BDBUF_FATAL_STATE_0,   RTEMS_BDBUF_FATAL_STATE_2, RTEMS_BDBUF_FATAL_STATE_4, RTEMS_BDBUF_FATAL_STATE_5, RTEMS_BDBUF_FATAL_STATE_6,   RTEMS_BDBUF_FATAL_STATE_7, RTEMS_BDBUF_FATAL_STATE_8, RTEMS_BDBUF_FATAL_STATE_9, RTEMS_BDBUF_FATAL_STATE_10,   RTEMS_BDBUF_FATAL_STATE_11, RTEMS_BDBUF_FATAL_SWAPOUT_RE, RTEMS_BDBUF_FATAL_SYNC_LOCK, RTEMS_BDBUF_FATAL_SYNC_UNLOCK,   RTEMS_BDBUF_FATAL_TREE_RM, RTEMS_BDBUF_FATAL_WAIT_EVNT, RTEMS_BDBUF_FATAL_WAIT_TRANS_EVNT, RTEMS_BDBUF_FATAL_ONCE,   RTEMS_BDBUF_FATAL_MTX_ATTR_INIT, RTEMS_BDBUF_FATAL_MTX_ATTR_SETPROTO, RTEMS_BDBUF_FATAL_CV_WAIT, RTEMS_BDBUF_FATAL_CV_BROADCAST }

Functions
rtems_status_code	rtems_bdbuf_init (void)
	Prepare buffering layer to work - initialize buffer descritors and (if it is neccessary) buffers. More...
rtems_status_code	rtems_bdbuf_get (rtems_disk_device *dd, rtems_blkdev_bnum block, rtems_bdbuf_buffer **bd_ptr)
	Get block buffer for data to be written into. More...
rtems_status_code	rtems_bdbuf_read (rtems_disk_device *dd, rtems_blkdev_bnum block, rtems_bdbuf_buffer **bd_ptr)
	Get the block buffer and if not already in the cache read from the disk. More...
rtems_status_code	rtems_bdbuf_release (rtems_bdbuf_buffer *bd)
	Release the buffer obtained by a read call back to the cache. More...
rtems_status_code	rtems_bdbuf_release_modified (rtems_bdbuf_buffer *bd)
	Release the buffer allocated with a get or read call placing it on the modified list. More...
rtems_status_code	rtems_bdbuf_sync (rtems_bdbuf_buffer *bd)
	Release the buffer as modified and wait until it has been synchronized with the disk by writing it. More...
rtems_status_code	rtems_bdbuf_syncdev (rtems_disk_device *dd)
	Synchronize all modified buffers for this device with the disk and wait until the transfers have completed. More...
void	rtems_bdbuf_purge_dev (rtems_disk_device *dd)
	Purges all buffers corresponding to the disk device dd. More...
rtems_status_code	rtems_bdbuf_set_block_size (rtems_disk_device *dd, uint32_t block_size, bool sync)
	Sets the block size of a disk device. More...
void	rtems_bdbuf_get_device_stats (const rtems_disk_device *dd, rtems_blkdev_stats *stats)
	Returns the block device statistics.
void	rtems_bdbuf_reset_device_stats (rtems_disk_device *dd)
	Resets the block device statistics.

Detailed Description

Block device buffer management.

Macro Definition Documentation

RTEMS_BDBUF_AVL_MAX_HEIGHT

#define RTEMS_BDBUF_AVL_MAX_HEIGHT   (32)

The default maximum height of 32 allows for AVL trees having between 5,704,880 and 4,294,967,295 nodes, depending on order of insertion.

You may change this compile-time constant as you wish.

RTEMS_BDBUF_CACHE_LOCK_ATTRIBS

#define RTEMS_BDBUF_CACHE_LOCK_ATTRIBS

Value:

(RTEMS_PRIORITY | RTEMS_BINARY_SEMAPHORE | \
   RTEMS_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL)

Lock semaphore attributes.

This is used for locking type mutexes.

Warning

Priority inheritance is on.

RTEMS_BDBUF_CACHE_WAITER_ATTRIBS

#define RTEMS_BDBUF_CACHE_WAITER_ATTRIBS

Value:

(RTEMS_PRIORITY | RTEMS_SIMPLE_BINARY_SEMAPHORE | \
   RTEMS_NO_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL)

Waiter semaphore attributes.

Warning

Do not configure as inherit priority. If a driver is in the driver initialisation table this locked semaphore will have the IDLE task as the holder and a blocking task will raise the priority of the IDLE task which can cause unsual side effects.

RTEMS_BDBUF_SWAPOUT_SYNC

#define RTEMS_BDBUF_SWAPOUT_SYNC   RTEMS_EVENT_2

The events used in this code.

These should be system events rather than application events.

RTEMS_BDBUF_WAIT_TIMEOUT

#define RTEMS_BDBUF_WAIT_TIMEOUT   RTEMS_NO_TIMEOUT

Waiter timeout.

Set to non-zero to find some info on a waiter that is waiting too long.

Typedef Documentation

rtems_bdbuf_swapout_transfer

typedef struct rtems_bdbuf_swapout_transfer rtems_bdbuf_swapout_transfer

A swapout transfer transaction data.

This data is passed to a worked thread to handle the write phase of the transfer.

rtems_bdbuf_swapout_worker

typedef struct rtems_bdbuf_swapout_worker rtems_bdbuf_swapout_worker

Swapout worker thread.

These are available to take processing from the main swapout thread and handle the I/O operation.