/*
 * Copyright (c) 1991 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)lfs_subr.c	7.13 (Berkeley) 07/05/92
 */

#include <sys/param.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/buf.h>
#include <sys/mount.h>

#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_extern.h>

/*
 * Return buffer with the contents of block "offset" from the beginning of
 * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
 * remaining space in the directory.
 */
int
lfs_blkatoff(ap)
	struct vop_blkatoff_args /* {
		struct vnode *a_vp;
		off_t a_offset;
		char **a_res;
		struct buf **a_bpp;
	} */ *ap;
{
	register struct lfs *fs;
	struct inode *ip;
	struct buf *bp;
	daddr_t lbn;
	int bsize, error;

	ip = VTOI(ap->a_vp);
	fs = ip->i_lfs;
	lbn = lblkno(fs, ap->a_offset);
	bsize = blksize(fs);

	*ap->a_bpp = NULL;
	if (error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) {
		brelse(bp);
		return (error);
	}
	if (ap->a_res)
		*ap->a_res = bp->b_un.b_addr + blkoff(fs, ap->a_offset);
	*ap->a_bpp = bp;
	return (0);
}

/*
 * lfs_seglock --
 *	Single thread the segment writer.
 */
void
lfs_seglock(fs)
	struct lfs *fs;
{
	while (fs->lfs_seglock)
		(void)tsleep(&fs->lfs_seglock, PRIBIO + 1, "lfs seglock", 0);
	fs->lfs_seglock = 1;
}

/*
 * lfs_segunlock --
 *	Single thread the segment writer.
 */
void
lfs_segunlock(fs)
	struct lfs *fs;
{
	fs->lfs_seglock = 0;
	wakeup(&fs->lfs_seglock);	/* XXX: May not be necessary. */
}