xfs_extfree_item.c

linux 内核源代码

	uint i;
	uint len = sizeof(xfs_efi_log_format_t) + 
		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_t);  
	uint len32 = sizeof(xfs_efi_log_format_32_t) + 
		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_32_t);  
	uint len64 = sizeof(xfs_efi_log_format_64_t) + 
		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_64_t);  

	if (buf->i_len == len) {
		memcpy((char *)dst_efi_fmt, (char*)src_efi_fmt, len);
		return 0;
	} else if (buf->i_len == len32) {
		xfs_efi_log_format_32_t *src_efi_fmt_32 =
			(xfs_efi_log_format_32_t *)buf->i_addr;

		dst_efi_fmt->efi_type     = src_efi_fmt_32->efi_type;
		dst_efi_fmt->efi_size     = src_efi_fmt_32->efi_size;
		dst_efi_fmt->efi_nextents = src_efi_fmt_32->efi_nextents;
		dst_efi_fmt->efi_id       = src_efi_fmt_32->efi_id;
		for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
			dst_efi_fmt->efi_extents[i].ext_start =
				src_efi_fmt_32->efi_extents[i].ext_start;
			dst_efi_fmt->efi_extents[i].ext_len =
				src_efi_fmt_32->efi_extents[i].ext_len;
		}
		return 0;
	} else if (buf->i_len == len64) {
		xfs_efi_log_format_64_t *src_efi_fmt_64 =
			(xfs_efi_log_format_64_t *)buf->i_addr;

		dst_efi_fmt->efi_type     = src_efi_fmt_64->efi_type;
		dst_efi_fmt->efi_size     = src_efi_fmt_64->efi_size;
		dst_efi_fmt->efi_nextents = src_efi_fmt_64->efi_nextents;
		dst_efi_fmt->efi_id       = src_efi_fmt_64->efi_id;
		for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
			dst_efi_fmt->efi_extents[i].ext_start =
				src_efi_fmt_64->efi_extents[i].ext_start;
			dst_efi_fmt->efi_extents[i].ext_len =
				src_efi_fmt_64->efi_extents[i].ext_len;
		}
		return 0;
	}
	return EFSCORRUPTED;
}

/*
 * This is called by the efd item code below to release references to
 * the given efi item.  Each efd calls this with the number of
 * extents that it has logged, and when the sum of these reaches
 * the total number of extents logged by this efi item we can free
 * the efi item.
 *
 * Freeing the efi item requires that we remove it from the AIL.
 * We'll use the AIL lock to protect our counters as well as
 * the removal from the AIL.
 */
void
xfs_efi_release(xfs_efi_log_item_t	*efip,
		uint			nextents)
{
	xfs_mount_t	*mp;
	int		extents_left;
	SPLDECL(s);

	mp = efip->efi_item.li_mountp;
	ASSERT(efip->efi_next_extent > 0);
	ASSERT(efip->efi_flags & XFS_EFI_COMMITTED);

	AIL_LOCK(mp, s);
	ASSERT(efip->efi_next_extent >= nextents);
	efip->efi_next_extent -= nextents;
	extents_left = efip->efi_next_extent;
	if (extents_left == 0) {
		/*
		 * xfs_trans_delete_ail() drops the AIL lock.
		 */
		xfs_trans_delete_ail(mp, (xfs_log_item_t *)efip, s);
		xfs_efi_item_free(efip);
	} else {
		AIL_UNLOCK(mp, s);
	}
}

STATIC void
xfs_efd_item_free(xfs_efd_log_item_t *efdp)
{
	int nexts = efdp->efd_format.efd_nextents;

	if (nexts > XFS_EFD_MAX_FAST_EXTENTS) {
		kmem_free(efdp, sizeof(xfs_efd_log_item_t) +
				(nexts - 1) * sizeof(xfs_extent_t));
	} else {
		kmem_zone_free(xfs_efd_zone, efdp);
	}
}

/*
 * This returns the number of iovecs needed to log the given efd item.
 * We only need 1 iovec for an efd item.  It just logs the efd_log_format
 * structure.
 */
/*ARGSUSED*/
STATIC uint
xfs_efd_item_size(xfs_efd_log_item_t *efdp)
{
	return 1;
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given efd log item. We use only 1 iovec, and we point that
 * at the efd_log_format structure embedded in the efd item.
 * It is at this point that we assert that all of the extent
 * slots in the efd item have been filled.
 */
STATIC void
xfs_efd_item_format(xfs_efd_log_item_t	*efdp,
		    xfs_log_iovec_t	*log_vector)
{
	uint	size;

	ASSERT(efdp->efd_next_extent == efdp->efd_format.efd_nextents);

	efdp->efd_format.efd_type = XFS_LI_EFD;

	size = sizeof(xfs_efd_log_format_t);
	size += (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
	efdp->efd_format.efd_size = 1;

	log_vector->i_addr = (xfs_caddr_t)&(efdp->efd_format);
	log_vector->i_len = size;
	XLOG_VEC_SET_TYPE(log_vector, XLOG_REG_TYPE_EFD_FORMAT);
	ASSERT(size >= sizeof(xfs_efd_log_format_t));
}


/*
 * Pinning has no meaning for an efd item, so just return.
 */
/*ARGSUSED*/
STATIC void
xfs_efd_item_pin(xfs_efd_log_item_t *efdp)
{
	return;
}


/*
 * Since pinning has no meaning for an efd item, unpinning does
 * not either.
 */
/*ARGSUSED*/
STATIC void
xfs_efd_item_unpin(xfs_efd_log_item_t *efdp, int stale)
{
	return;
}

/*ARGSUSED*/
STATIC void
xfs_efd_item_unpin_remove(xfs_efd_log_item_t *efdp, xfs_trans_t *tp)
{
	return;
}

/*
 * Efd items have no locking, so just return success.
 */
/*ARGSUSED*/
STATIC uint
xfs_efd_item_trylock(xfs_efd_log_item_t *efdp)
{
	return XFS_ITEM_LOCKED;
}

/*
 * Efd items have no locking or pushing, so return failure
 * so that the caller doesn't bother with us.
 */
/*ARGSUSED*/
STATIC void
xfs_efd_item_unlock(xfs_efd_log_item_t *efdp)
{
	if (efdp->efd_item.li_flags & XFS_LI_ABORTED)
		xfs_efd_item_free(efdp);
	return;
}

/*
 * When the efd item is committed to disk, all we need to do
 * is delete our reference to our partner efi item and then
 * free ourselves.  Since we're freeing ourselves we must
 * return -1 to keep the transaction code from further referencing
 * this item.
 */
/*ARGSUSED*/
STATIC xfs_lsn_t
xfs_efd_item_committed(xfs_efd_log_item_t *efdp, xfs_lsn_t lsn)
{
	/*
	 * If we got a log I/O error, it's always the case that the LR with the
	 * EFI got unpinned and freed before the EFD got aborted.
	 */
	if ((efdp->efd_item.li_flags & XFS_LI_ABORTED) == 0)
		xfs_efi_release(efdp->efd_efip, efdp->efd_format.efd_nextents);

	xfs_efd_item_free(efdp);
	return (xfs_lsn_t)-1;
}

/*
 * There isn't much you can do to push on an efd item.  It is simply
 * stuck waiting for the log to be flushed to disk.
 */
/*ARGSUSED*/
STATIC void
xfs_efd_item_push(xfs_efd_log_item_t *efdp)
{
	return;
}

/*
 * The EFD dependency tracking op doesn't do squat.  It can't because
 * it doesn't know where the free extent is coming from.  The dependency
 * tracking has to be handled by the "enclosing" metadata object.  For
 * example, for inodes, the inode is locked throughout the extent freeing
 * so the dependency should be recorded there.
 */
/*ARGSUSED*/
STATIC void
xfs_efd_item_committing(xfs_efd_log_item_t *efip, xfs_lsn_t lsn)
{
	return;
}

/*
 * This is the ops vector shared by all efd log items.
 */
static struct xfs_item_ops xfs_efd_item_ops = {
	.iop_size	= (uint(*)(xfs_log_item_t*))xfs_efd_item_size,
	.iop_format	= (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
					xfs_efd_item_format,
	.iop_pin	= (void(*)(xfs_log_item_t*))xfs_efd_item_pin,
	.iop_unpin	= (void(*)(xfs_log_item_t*, int))xfs_efd_item_unpin,
	.iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t*))
					xfs_efd_item_unpin_remove,
	.iop_trylock	= (uint(*)(xfs_log_item_t*))xfs_efd_item_trylock,
	.iop_unlock	= (void(*)(xfs_log_item_t*))xfs_efd_item_unlock,
	.iop_committed	= (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_efd_item_committed,
	.iop_push	= (void(*)(xfs_log_item_t*))xfs_efd_item_push,
	.iop_pushbuf	= NULL,
	.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_efd_item_committing
};


/*
 * Allocate and initialize an efd item with the given number of extents.
 */
xfs_efd_log_item_t *
xfs_efd_init(xfs_mount_t	*mp,
	     xfs_efi_log_item_t	*efip,
	     uint		nextents)

{
	xfs_efd_log_item_t	*efdp;
	uint			size;

	ASSERT(nextents > 0);
	if (nextents > XFS_EFD_MAX_FAST_EXTENTS) {
		size = (uint)(sizeof(xfs_efd_log_item_t) +
			((nextents - 1) * sizeof(xfs_extent_t)));
		efdp = (xfs_efd_log_item_t*)kmem_zalloc(size, KM_SLEEP);
	} else {
		efdp = (xfs_efd_log_item_t*)kmem_zone_zalloc(xfs_efd_zone,
							     KM_SLEEP);
	}

	efdp->efd_item.li_type = XFS_LI_EFD;
	efdp->efd_item.li_ops = &xfs_efd_item_ops;
	efdp->efd_item.li_mountp = mp;
	efdp->efd_efip = efip;
	efdp->efd_format.efd_nextents = nextents;
	efdp->efd_format.efd_efi_id = efip->efi_format.efi_id;

	return (efdp);
}