#ifndef __PFS_BUF_H__

#define __PFS_BUF_H__

/* Buffer (block) cache.

*/

struct buf {

/* Data portion of the buffer. */

char b_data[PIPE_BUF]; /* ordinary user data */

/* Header portion of the buffer. */

struct buf *b_next; /* used to link all free bufs in a chain */

struct buf *b_prev; /* used to link all free bufs the other way */

ino_t b_num; /* inode number on minor device */

dev_t b_dev; /* major | minor device where block resides */

int b_bytes; /* Number of bytes allocated in bp */

int b_count; /* Number of users of this buffer */

};

/* A block is free if b_dev == NO_DEV. */

EXTERN struct buf *front; /* points to least recently used free block */

EXTERN struct buf *rear; /* points to most recently used free block */

#endif