xfs_fsops.c

linux 内核源代码

		 */
		error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
		if (error) {
			goto error0;
		}
		ASSERT(bp);
		agf = XFS_BUF_TO_AGF(bp);
		be32_add(&agf->agf_length, new);
		ASSERT(be32_to_cpu(agf->agf_length) ==
		       be32_to_cpu(agi->agi_length));
		xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
		/*
		 * Free the new space.
		 */
		error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
			be32_to_cpu(agf->agf_length) - new), new);
		if (error) {
			goto error0;
		}
	}
	if (nagcount > oagcount)
		xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
	if (nb > mp->m_sb.sb_dblocks)
		xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
				 nb - mp->m_sb.sb_dblocks);
	if (nfree)
		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
	if (dpct)
		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
	error = xfs_trans_commit(tp, 0);
	if (error) {
		return error;
	}
	/* New allocation groups fully initialized, so update mount struct */
	if (nagimax)
		mp->m_maxagi = nagimax;
	if (mp->m_sb.sb_imax_pct) {
		__uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
		do_div(icount, 100);
		mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
	} else
		mp->m_maxicount = 0;
	for (agno = 1; agno < nagcount; agno++) {
		error = xfs_read_buf(mp, mp->m_ddev_targp,
				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
				  XFS_FSS_TO_BB(mp, 1), 0, &bp);
		if (error) {
			xfs_fs_cmn_err(CE_WARN, mp,
			"error %d reading secondary superblock for ag %d",
				error, agno);
			break;
		}
		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
		/*
		 * If we get an error writing out the alternate superblocks,
		 * just issue a warning and continue.  The real work is
		 * already done and committed.
		 */
		if (!(error = xfs_bwrite(mp, bp))) {
			continue;
		} else {
			xfs_fs_cmn_err(CE_WARN, mp,
		"write error %d updating secondary superblock for ag %d",
				error, agno);
			break; /* no point in continuing */
		}
	}
	return 0;

 error0:
	xfs_trans_cancel(tp, XFS_TRANS_ABORT);
	return error;
}

static int
xfs_growfs_log_private(
	xfs_mount_t		*mp,	/* mount point for filesystem */
	xfs_growfs_log_t	*in)	/* growfs log input struct */
{
	xfs_extlen_t		nb;

	nb = in->newblocks;
	if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
		return XFS_ERROR(EINVAL);
	if (nb == mp->m_sb.sb_logblocks &&
	    in->isint == (mp->m_sb.sb_logstart != 0))
		return XFS_ERROR(EINVAL);
	/*
	 * Moving the log is hard, need new interfaces to sync
	 * the log first, hold off all activity while moving it.
	 * Can have shorter or longer log in the same space,
	 * or transform internal to external log or vice versa.
	 */
	return XFS_ERROR(ENOSYS);
}

/*
 * protected versions of growfs function acquire and release locks on the mount
 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
 * XFS_IOC_FSGROWFSRT
 */


int
xfs_growfs_data(
	xfs_mount_t		*mp,
	xfs_growfs_data_t	*in)
{
	int error;
	if (!mutex_trylock(&mp->m_growlock))
		return XFS_ERROR(EWOULDBLOCK);
	error = xfs_growfs_data_private(mp, in);
	mutex_unlock(&mp->m_growlock);
	return error;
}

int
xfs_growfs_log(
	xfs_mount_t		*mp,
	xfs_growfs_log_t	*in)
{
	int error;
	if (!mutex_trylock(&mp->m_growlock))
		return XFS_ERROR(EWOULDBLOCK);
	error = xfs_growfs_log_private(mp, in);
	mutex_unlock(&mp->m_growlock);
	return error;
}

/*
 * exported through ioctl XFS_IOC_FSCOUNTS
 */

int
xfs_fs_counts(
	xfs_mount_t		*mp,
	xfs_fsop_counts_t	*cnt)
{
	unsigned long	s;

	xfs_icsb_sync_counters_flags(mp, XFS_ICSB_LAZY_COUNT);
	s = XFS_SB_LOCK(mp);
	cnt->freedata = mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
	cnt->freertx = mp->m_sb.sb_frextents;
	cnt->freeino = mp->m_sb.sb_ifree;
	cnt->allocino = mp->m_sb.sb_icount;
	XFS_SB_UNLOCK(mp, s);
	return 0;
}

/*
 * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
 *
 * xfs_reserve_blocks is called to set m_resblks
 * in the in-core mount table. The number of unused reserved blocks
 * is kept in m_resblks_avail.
 *
 * Reserve the requested number of blocks if available. Otherwise return
 * as many as possible to satisfy the request. The actual number
 * reserved are returned in outval
 *
 * A null inval pointer indicates that only the current reserved blocks
 * available  should  be returned no settings are changed.
 */

int
xfs_reserve_blocks(
	xfs_mount_t             *mp,
	__uint64_t              *inval,
	xfs_fsop_resblks_t      *outval)
{
	__int64_t		lcounter, delta, fdblks_delta;
	__uint64_t		request;
	unsigned long		s;

	/* If inval is null, report current values and return */
	if (inval == (__uint64_t *)NULL) {
		if (!outval)
			return EINVAL;
		outval->resblks = mp->m_resblks;
		outval->resblks_avail = mp->m_resblks_avail;
		return 0;
	}

	request = *inval;

	/*
	 * With per-cpu counters, this becomes an interesting
	 * problem. we needto work out if we are freeing or allocation
	 * blocks first, then we can do the modification as necessary.
	 *
	 * We do this under the XFS_SB_LOCK so that if we are near
	 * ENOSPC, we will hold out any changes while we work out
	 * what to do. This means that the amount of free space can
	 * change while we do this, so we need to retry if we end up
	 * trying to reserve more space than is available.
	 *
	 * We also use the xfs_mod_incore_sb() interface so that we
	 * don't have to care about whether per cpu counter are
	 * enabled, disabled or even compiled in....
	 */
retry:
	s = XFS_SB_LOCK(mp);
	xfs_icsb_sync_counters_flags(mp, XFS_ICSB_SB_LOCKED);

	/*
	 * If our previous reservation was larger than the current value,
	 * then move any unused blocks back to the free pool.
	 */
	fdblks_delta = 0;
	if (mp->m_resblks > request) {
		lcounter = mp->m_resblks_avail - request;
		if (lcounter  > 0) {		/* release unused blocks */
			fdblks_delta = lcounter;
			mp->m_resblks_avail -= lcounter;
		}
		mp->m_resblks = request;
	} else {
		__int64_t	free;

		free =  mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
		if (!free)
			goto out; /* ENOSPC and fdblks_delta = 0 */

		delta = request - mp->m_resblks;
		lcounter = free - delta;
		if (lcounter < 0) {
			/* We can't satisfy the request, just get what we can */
			mp->m_resblks += free;
			mp->m_resblks_avail += free;
			fdblks_delta = -free;
			mp->m_sb.sb_fdblocks = XFS_ALLOC_SET_ASIDE(mp);
		} else {
			fdblks_delta = -delta;
			mp->m_sb.sb_fdblocks =
				lcounter + XFS_ALLOC_SET_ASIDE(mp);
			mp->m_resblks = request;
			mp->m_resblks_avail += delta;
		}
	}
out:
	if (outval) {
		outval->resblks = mp->m_resblks;
		outval->resblks_avail = mp->m_resblks_avail;
	}
	XFS_SB_UNLOCK(mp, s);

	if (fdblks_delta) {
		/*
		 * If we are putting blocks back here, m_resblks_avail is
		 * already at it's max so this will put it in the free pool.
		 *
		 * If we need space, we'll either succeed in getting it
		 * from the free block count or we'll get an enospc. If
		 * we get a ENOSPC, it means things changed while we were
		 * calculating fdblks_delta and so we should try again to
		 * see if there is anything left to reserve.
		 *
		 * Don't set the reserved flag here - we don't want to reserve
		 * the extra reserve blocks from the reserve.....
		 */
		int error;
		error = xfs_mod_incore_sb(mp, XFS_SBS_FDBLOCKS, fdblks_delta, 0);
		if (error == ENOSPC)
			goto retry;
	}

	return 0;
}

void
xfs_fs_log_dummy(
	xfs_mount_t	*mp)
{
	xfs_trans_t	*tp;
	xfs_inode_t	*ip;

	tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
	if (xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0)) {
		xfs_trans_cancel(tp, 0);
		return;
	}

	ip = mp->m_rootip;
	xfs_ilock(ip, XFS_ILOCK_EXCL);

	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
	xfs_trans_ihold(tp, ip);
	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	xfs_trans_set_sync(tp);
	xfs_trans_commit(tp, 0);

	xfs_iunlock(ip, XFS_ILOCK_EXCL);
}

int
xfs_fs_goingdown(
	xfs_mount_t	*mp,
	__uint32_t	inflags)
{
	switch (inflags) {
	case XFS_FSOP_GOING_FLAGS_DEFAULT: {
		struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);

		if (sb && !IS_ERR(sb)) {
			xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
			thaw_bdev(sb->s_bdev, sb);
		}
	
		break;
	}
	case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
		xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
		break;
	case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
		xfs_force_shutdown(mp,
				SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
		break;
	default:
		return XFS_ERROR(EINVAL);
	}

	return 0;
}