C++ M_RES函数代码示例

/*
 * Iterate over the log space reservation table to figure out and return
 * the maximum one in terms of the pre-calculated values which were done
 * at mount time.
 */
STATIC void
xfs_log_get_max_trans_res(
	struct xfs_mount	*mp,
	struct xfs_trans_res	*max_resp)
{
	struct xfs_trans_res	*resp;
	struct xfs_trans_res	*end_resp;
	int			log_space = 0;
	int			attr_space;

	attr_space = xfs_log_calc_max_attrsetm_res(mp);

	resp = (struct xfs_trans_res *)M_RES(mp);
	end_resp = (struct xfs_trans_res *)(M_RES(mp) + 1);
	for (; resp < end_resp; resp++) {
		int		tmp = resp->tr_logcount > 1 ?
				      resp->tr_logres * resp->tr_logcount :
				      resp->tr_logres;
		if (log_space < tmp) {
			log_space = tmp;
			*max_resp = *resp;		/* struct copy */
		}
	}

	if (attr_space > log_space) {
		*max_resp = M_RES(mp)->tr_attrsetm;	/* struct copy */
		max_resp->tr_logres = attr_space;
	}
}

STATIC int
xfs_qm_log_quotaoff_end(
    xfs_mount_t		*mp,
    xfs_qoff_logitem_t	*startqoff,
    uint			flags)
{
    xfs_trans_t		*tp;
    int			error;
    xfs_qoff_logitem_t	*qoffi;

    tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QUOTAOFF_END);

    error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_equotaoff, 0, 0);
    if (error) {
        xfs_trans_cancel(tp, 0);
        return (error);
    }

    qoffi = xfs_trans_get_qoff_item(tp, startqoff,
                                    flags & XFS_ALL_QUOTA_ACCT);
    xfs_trans_log_quotaoff_item(tp, qoffi);

    /*
     * We have to make sure that the transaction is secure on disk before we
     * return and actually stop quota accounting. So, make it synchronous.
     * We don't care about quotoff's performance.
     */
    xfs_trans_set_sync(tp);
    error = xfs_trans_commit(tp, 0);
    return (error);
}

STATIC int
xfs_vn_update_time(
	struct inode		*inode,
	struct timespec		*now,
	int			flags)
{
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
	struct xfs_trans	*tp;
	int			error;

	trace_xfs_update_time(ip);

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
	if (error)
		return error;

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	if (flags & S_CTIME)
		inode->i_ctime = *now;
	if (flags & S_MTIME)
		inode->i_mtime = *now;
	if (flags & S_ATIME)
		inode->i_atime = *now;

	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
	xfs_trans_log_inode(tp, ip, XFS_ILOG_TIMESTAMP);
	return xfs_trans_commit(tp);
}

/*
 * Clear the inode reflink flag if there are no shared extents and the size
 * hasn't changed.
 */
STATIC int
xfs_reflink_try_clear_inode_flag(
	struct xfs_inode	*ip)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct xfs_trans	*tp;
	int			error = 0;

	/* Start a rolling transaction to remove the mappings */
	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
	if (error)
		return error;

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, 0);

	error = xfs_reflink_clear_inode_flag(ip, &tp);
	if (error)
		goto cancel;

	error = xfs_trans_commit(tp);
	if (error)
		goto out;

	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	return 0;
cancel:
	xfs_trans_cancel(tp);
out:
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	return error;
}

STATIC int
xfs_setfilesize_trans_alloc(
	struct xfs_ioend	*ioend)
{
	struct xfs_mount	*mp = XFS_I(ioend->io_inode)->i_mount;
	struct xfs_trans	*tp;
	int			error;

	tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);

	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0);
	if (error) {
		xfs_trans_cancel(tp);
		return error;
	}

	ioend->io_append_trans = tp;

	/*
	 * We may pass freeze protection with a transaction.  So tell lockdep
	 * we released it.
	 */
	__sb_writers_release(ioend->io_inode->i_sb, SB_FREEZE_FS);
	/*
	 * We hand off the transaction to the completion thread now, so
	 * clear the flag here.
	 */
	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
	return 0;
}

/*
 * Calculate the maximum length in bytes that would be required for a local
 * attribute value as large attributes out of line are not logged.
 */
STATIC int
xfs_log_calc_max_attrsetm_res(
	struct xfs_mount	*mp)
{
	int			size;
	int			nblks;

	size = xfs_attr_leaf_entsize_local_max(mp->m_sb.sb_blocksize) -
	       MAXNAMELEN - 1;
	nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
	nblks += XFS_B_TO_FSB(mp, size);
	nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK);

	return  M_RES(mp)->tr_attrsetm.tr_logres +
		M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
}

/* Allocate and initialize the dquot buffer for this in-core dquot. */
static int
xfs_qm_dqread_alloc(
	struct xfs_mount	*mp,
	struct xfs_dquot	*dqp,
	struct xfs_buf		**bpp)
{
	struct xfs_trans	*tp;
	int			error;

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc,
			XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp);
	if (error)
		goto err;

	error = xfs_dquot_disk_alloc(&tp, dqp, bpp);
	if (error)
		goto err_cancel;

	error = xfs_trans_commit(tp);
	if (error) {
		/*
		 * Buffer was held to the transaction, so we have to unlock it
		 * manually here because we're not passing it back.
		 */
		xfs_buf_relse(*bpp);
		*bpp = NULL;
		goto err;
	}
	return 0;

err_cancel:
	xfs_trans_cancel(tp);
err:
	return error;
}

int
xfs_update_prealloc_flags(
	struct xfs_inode	*ip,
	enum xfs_prealloc_flags	flags)
{
	struct xfs_trans	*tp;
	int			error;

	error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid,
			0, 0, 0, &tp);
	if (error)
		return error;

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);

	if (!(flags & XFS_PREALLOC_INVISIBLE)) {
		VFS_I(ip)->i_mode &= ~S_ISUID;
		if (VFS_I(ip)->i_mode & S_IXGRP)
			VFS_I(ip)->i_mode &= ~S_ISGID;
		xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
	}

	if (flags & XFS_PREALLOC_SET)
		ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
	if (flags & XFS_PREALLOC_CLEAR)
		ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;

	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	if (flags & XFS_PREALLOC_SYNC)
		xfs_trans_set_sync(tp);
	return xfs_trans_commit(tp);
}

int
xfs_set_dmattrs(
	xfs_inode_t     *ip,
	u_int		evmask,
	u_int16_t	state)
{
	xfs_mount_t	*mp = ip->i_mount;
	xfs_trans_t	*tp;
	int		error;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (XFS_FORCED_SHUTDOWN(mp))
		return -EIO;

	tp = xfs_trans_alloc(mp, XFS_TRANS_SET_DMATTRS);
	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
	if (error) {
		xfs_trans_cancel(tp, 0);
		return error;
	}
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);

	ip->i_d.di_dmevmask = evmask;
	ip->i_d.di_dmstate  = state;

	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	error = xfs_trans_commit(tp, 0);

	return error;
}

/*
 * Ensure the reflink bit is set in both inodes.
 */
STATIC int
xfs_reflink_set_inode_flag(
	struct xfs_inode	*src,
	struct xfs_inode	*dest)
{
	struct xfs_mount	*mp = src->i_mount;
	int			error;
	struct xfs_trans	*tp;

	if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest))
		return 0;

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
	if (error)
		goto out_error;

	/* Lock both files against IO */
	if (src->i_ino == dest->i_ino)
		xfs_ilock(src, XFS_ILOCK_EXCL);
	else
		xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL);

	if (!xfs_is_reflink_inode(src)) {
		trace_xfs_reflink_set_inode_flag(src);
		xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL);
		src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK;
		xfs_trans_log_inode(tp, src, XFS_ILOG_CORE);
		xfs_ifork_init_cow(src);
	} else
		xfs_iunlock(src, XFS_ILOCK_EXCL);

	if (src->i_ino == dest->i_ino)
		goto commit_flags;

	if (!xfs_is_reflink_inode(dest)) {
		trace_xfs_reflink_set_inode_flag(dest);
		xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL);
		dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK;
		xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE);
		xfs_ifork_init_cow(dest);
	} else
		xfs_iunlock(dest, XFS_ILOCK_EXCL);

commit_flags:
	error = xfs_trans_commit(tp);
	if (error)
		goto out_error;
	return error;

out_error:
	trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_);
	return error;
}

STATIC int
xfs_qm_scall_trunc_qfile(
    struct xfs_mount	*mp,
    xfs_ino_t		ino)
{
    struct xfs_inode	*ip;
    struct xfs_trans	*tp;
    int			error;

    if (ino == NULLFSINO)
        return 0;

    error = xfs_iget(mp, NULL, ino, 0, 0, &ip);
    if (error)
        return error;

    xfs_ilock(ip, XFS_IOLOCK_EXCL);

    tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE);
    error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
    if (error) {
        xfs_trans_cancel(tp, 0);
        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
        goto out_put;
    }

    xfs_ilock(ip, XFS_ILOCK_EXCL);
    xfs_trans_ijoin(tp, ip, 0);

    ip->i_d.di_size = 0;
    xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

    error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
    if (error) {
        xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
                         XFS_TRANS_ABORT);
        goto out_unlock;
    }

    ASSERT(ip->i_d.di_nextents == 0);

    xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
    error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);

out_unlock:
    xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
out_put:
    IRELE(ip);
    return error;
}

/*
 * Cancel CoW reservations for some byte range of an inode.
 *
 * If cancel_real is true this function cancels all COW fork extents for the
 * inode; if cancel_real is false, real extents are not cleared.
 */
int
xfs_reflink_cancel_cow_range(
	struct xfs_inode	*ip,
	xfs_off_t		offset,
	xfs_off_t		count,
	bool			cancel_real)
{
	struct xfs_trans	*tp;
	xfs_fileoff_t		offset_fsb;
	xfs_fileoff_t		end_fsb;
	int			error;

	trace_xfs_reflink_cancel_cow_range(ip, offset, count);
	ASSERT(xfs_is_reflink_inode(ip));

	offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
	if (count == NULLFILEOFF)
		end_fsb = NULLFILEOFF;
	else
		end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count);

	/* Start a rolling transaction to remove the mappings */
	error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write,
			0, 0, 0, &tp);
	if (error)
		goto out;

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, 0);

	/* Scrape out the old CoW reservations */
	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
			cancel_real);
	if (error)
		goto out_cancel;

	error = xfs_trans_commit(tp);

	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	return error;

out_cancel:
	xfs_trans_cancel(tp);
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
out:
	trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_);
	return error;
}

STATIC int
xfs_qm_log_quotaoff(
    xfs_mount_t	       *mp,
    xfs_qoff_logitem_t     **qoffstartp,
    uint		       flags)
{
    xfs_trans_t	       *tp;
    int			error;
    xfs_qoff_logitem_t     *qoffi=NULL;
    uint			oldsbqflag=0;

    tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QUOTAOFF);
    error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_quotaoff, 0, 0);
    if (error)
        goto error0;

    qoffi = xfs_trans_get_qoff_item(tp, NULL, flags & XFS_ALL_QUOTA_ACCT);
    xfs_trans_log_quotaoff_item(tp, qoffi);

    spin_lock(&mp->m_sb_lock);
    oldsbqflag = mp->m_sb.sb_qflags;
    mp->m_sb.sb_qflags = (mp->m_qflags & ~(flags)) & XFS_MOUNT_QUOTA_ALL;
    spin_unlock(&mp->m_sb_lock);

    xfs_mod_sb(tp, XFS_SB_QFLAGS);

    /*
     * We have to make sure that the transaction is secure on disk before we
     * return and actually stop quota accounting. So, make it synchronous.
     * We don't care about quotoff's performance.
     */
    xfs_trans_set_sync(tp);
    error = xfs_trans_commit(tp, 0);

error0:
    if (error) {
        xfs_trans_cancel(tp, 0);
        /*
         * No one else is modifying sb_qflags, so this is OK.
         * We still hold the quotaofflock.
         */
        spin_lock(&mp->m_sb_lock);
        mp->m_sb.sb_qflags = oldsbqflag;
        spin_unlock(&mp->m_sb_lock);
    }
    *qoffstartp = qoffi;
    return (error);
}

int
xfs_setfilesize(
	struct xfs_inode	*ip,
	xfs_off_t		offset,
	size_t			size)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct xfs_trans	*tp;
	int			error;

	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
	if (error)
		return error;

	return __xfs_setfilesize(ip, tp, offset, size);
}

/*
 * Set up the transaction structure for the setattr operation, checking that we
 * have permission to do so. On success, return a clean transaction and the
 * inode locked exclusively ready for further operation specific checks. On
 * failure, return an error without modifying or locking the inode.
 *
 * The inode might already be IO locked on call. If this is the case, it is
 * indicated in @join_flags and we take full responsibility for ensuring they
 * are unlocked from now on. Hence if we have an error here, we still have to
 * unlock them. Otherwise, once they are joined to the transaction, they will
 * be unlocked on commit/cancel.
 */
static struct xfs_trans *
xfs_ioctl_setattr_get_trans(
	struct xfs_inode	*ip,
	int			join_flags)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct xfs_trans	*tp;
	int			error = -EROFS;

	if (mp->m_flags & XFS_MOUNT_RDONLY)
		goto out_unlock;
	error = -EIO;
	if (XFS_FORCED_SHUTDOWN(mp))
		goto out_unlock;

	tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
	if (error)
		goto out_cancel;

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | join_flags);
	join_flags = 0;

	/*
	 * CAP_FOWNER overrides the following restrictions:
	 *
	 * The user ID of the calling process must be equal to the file owner
	 * ID, except in cases where the CAP_FSETID capability is applicable.
	 */
	if (!inode_owner_or_capable(VFS_I(ip))) {
		error = -EPERM;
		goto out_cancel;
	}

	if (mp->m_flags & XFS_MOUNT_WSYNC)
		xfs_trans_set_sync(tp);

	return tp;

out_cancel:
	xfs_trans_cancel(tp);
out_unlock:
	if (join_flags)
		xfs_iunlock(ip, join_flags);
	return ERR_PTR(error);
}