[SOLVED] CS代考计算机代写 file system #include “filesys/free-map.h”

#include “filesys/free-map.h”
#include
#include
#include “filesys/file.h”
#include “filesys/filesys.h”
#include “filesys/inode.h”

static struct file *free_map_file; /* Free map file. */
static struct bitmap *free_map;/* Free map, one bit per sector. */

/* Initializes the free map. */
void
free_map_init (void)
{
free_map = bitmap_create (block_size (fs_device));
if (free_map == NULL)
PANIC (“bitmap creation failed–file system device is too large”);
bitmap_mark (free_map, FREE_MAP_SECTOR);
bitmap_mark (free_map, ROOT_DIR_SECTOR);
}

/* Allocates CNT consecutive sectors from the free map and stores
the first into *SECTORP.
Returns true if successful, false if not enough consecutive
sectors were available or if the free_map file could not be
written. */
bool
free_map_allocate (size_t cnt, block_sector_t *sectorp)
{
block_sector_t sector = bitmap_scan_and_flip (free_map, 0, cnt, false);
if (sector != BITMAP_ERROR
&& free_map_file != NULL
&& !bitmap_write (free_map, free_map_file))
{
bitmap_set_multiple (free_map, sector, cnt, false);
sector = BITMAP_ERROR;
}
if (sector != BITMAP_ERROR)
*sectorp = sector;
return sector != BITMAP_ERROR;
}

/* Makes CNT sectors starting at SECTOR available for use. */
void
free_map_release (block_sector_t sector, size_t cnt)
{
ASSERT (bitmap_all (free_map, sector, cnt));
bitmap_set_multiple (free_map, sector, cnt, false);
bitmap_write (free_map, free_map_file);
}

/* Opens the free map file and reads it from disk. */
void
free_map_open (void)
{
free_map_file = file_open (inode_open (FREE_MAP_SECTOR));
if (free_map_file == NULL)
PANIC (“can’t open free map”);
if (!bitmap_read (free_map, free_map_file))
PANIC (“can’t read free map”);
}

/* Writes the free map to disk and closes the free map file. */
void
free_map_close (void)
{
file_close (free_map_file);
}

/* Creates a new free map file on disk and writes the free map to
it. */
void
free_map_create (void)
{
/* Create inode. */
if (!inode_create (FREE_MAP_SECTOR, bitmap_file_size (free_map)))
PANIC (“free map creation failed”);

/* Write bitmap to file. */
free_map_file = file_open (inode_open (FREE_MAP_SECTOR));
if (free_map_file == NULL)
PANIC (“can’t open free map”);
if (!bitmap_write (free_map, free_map_file))
PANIC (“can’t write free map”);
}