code: mafs

ref: 5c21eca829380c28769f79beabb7cc51f1787f97
dir: /dev.c/

#include <u.h>
#include <libc.h>
#include "dat.h"
#include "fns.h"

int devfd = -1;	/* device fd */

u64
devsize(void)
{
	Dir *dir;
	u64 size;

	if((dir = dirfstat(devfd)) == nil)
		panic("can't stat device\n");
	size = dir->length;
	free(dir);
	return size;
}

/* TODO proper error handling */
int
devread(u64 blkno, void *b, u16 len)
{
	int n;

	if((n= pread(devfd, b, len*Rawblocksize, blkno*Rawblocksize)) != len*Rawblocksize)
		panic("devread failed: %r\n");
	/* print("devread i %d n %d\n", i, n); */
	return n;
}

int
devwritedirty(u64 blkno, u8 dirty)
{
	int n;

	if((n = pwrite(devfd, &dirty, 1, blkno*Rawblocksize +Nthdirty)) != 1)
		panic("devwrite failed: %r\n");
	return n;
}

int
devwritedirtyclear(u64 blkno)
{
	return devwritedirty(blkno, 0);
}

/* obsolete
int
devwritedirtyset(u64 blkno)
{
	return devwritedirty(blkno, 1);
}
*/

int
devwrite(u64 blkno, void *b, u16 len)
{
	int n;

	if((n = pwrite(devfd, b, len*Rawblocksize, blkno*Rawblocksize)) != len*Rawblocksize)
		panic("devwrite failed: %r\n");
	return n;
}

/* obsoleted, a hack for more efficient logging */
/*int
devrawwrite(void *b, int len, u64 offset)
{
	int i, n;

	qlock(&d);
	i = (n = pwrite(devfd, b, len, offset)) != len;
	qunlock(&d);
	if(i)
		panic("devrawwrite failed: %r\n");
	return n;
}*/

u64
devinit(char *devfile)
{
	devfd = open(devfile, ORDWR);
	if(devfd < 0)
		panic("can't open %s", devfile);
	seek(devfd, 0, 0);
	return devsize();
}