xfs_extfree_item.c

linux 内核源代码

/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_extfree_item.h"


kmem_zone_t	*xfs_efi_zone;
kmem_zone_t	*xfs_efd_zone;

STATIC void	xfs_efi_item_unlock(xfs_efi_log_item_t *);

void
xfs_efi_item_free(xfs_efi_log_item_t *efip)
{
	int nexts = efip->efi_format.efi_nextents;

	if (nexts > XFS_EFI_MAX_FAST_EXTENTS) {
		kmem_free(efip, sizeof(xfs_efi_log_item_t) +
				(nexts - 1) * sizeof(xfs_extent_t));
	} else {
		kmem_zone_free(xfs_efi_zone, efip);
	}
}

/*
 * This returns the number of iovecs needed to log the given efi item.
 * We only need 1 iovec for an efi item.  It just logs the efi_log_format
 * structure.
 */
/*ARGSUSED*/
STATIC uint
xfs_efi_item_size(xfs_efi_log_item_t *efip)
{
	return 1;
}

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

	ASSERT(efip->efi_next_extent == efip->efi_format.efi_nextents);

	efip->efi_format.efi_type = XFS_LI_EFI;

	size = sizeof(xfs_efi_log_format_t);
	size += (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
	efip->efi_format.efi_size = 1;

	log_vector->i_addr = (xfs_caddr_t)&(efip->efi_format);
	log_vector->i_len = size;
	XLOG_VEC_SET_TYPE(log_vector, XLOG_REG_TYPE_EFI_FORMAT);
	ASSERT(size >= sizeof(xfs_efi_log_format_t));
}


/*
 * Pinning has no meaning for an efi item, so just return.
 */
/*ARGSUSED*/
STATIC void
xfs_efi_item_pin(xfs_efi_log_item_t *efip)
{
	return;
}


/*
 * While EFIs cannot really be pinned, the unpin operation is the
 * last place at which the EFI is manipulated during a transaction.
 * Here we coordinate with xfs_efi_cancel() to determine who gets to
 * free the EFI.
 */
/*ARGSUSED*/
STATIC void
xfs_efi_item_unpin(xfs_efi_log_item_t *efip, int stale)
{
	xfs_mount_t	*mp;
	SPLDECL(s);

	mp = efip->efi_item.li_mountp;
	AIL_LOCK(mp, s);
	if (efip->efi_flags & XFS_EFI_CANCELED) {
		/*
		 * 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 {
		efip->efi_flags |= XFS_EFI_COMMITTED;
		AIL_UNLOCK(mp, s);
	}
}

/*
 * like unpin only we have to also clear the xaction descriptor
 * pointing the log item if we free the item.  This routine duplicates
 * unpin because efi_flags is protected by the AIL lock.  Freeing
 * the descriptor and then calling unpin would force us to drop the AIL
 * lock which would open up a race condition.
 */
STATIC void
xfs_efi_item_unpin_remove(xfs_efi_log_item_t *efip, xfs_trans_t *tp)
{
	xfs_mount_t	*mp;
	xfs_log_item_desc_t	*lidp;
	SPLDECL(s);

	mp = efip->efi_item.li_mountp;
	AIL_LOCK(mp, s);
	if (efip->efi_flags & XFS_EFI_CANCELED) {
		/*
		 * free the xaction descriptor pointing to this item
		 */
		lidp = xfs_trans_find_item(tp, (xfs_log_item_t *) efip);
		xfs_trans_free_item(tp, lidp);
		/*
		 * pull the item off the AIL.
		 * 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 {
		efip->efi_flags |= XFS_EFI_COMMITTED;
		AIL_UNLOCK(mp, s);
	}
}

/*
 * Efi items have no locking or pushing.  However, since EFIs are
 * pulled from the AIL when their corresponding EFDs are committed
 * to disk, their situation is very similar to being pinned.  Return
 * XFS_ITEM_PINNED so that the caller will eventually flush the log.
 * This should help in getting the EFI out of the AIL.
 */
/*ARGSUSED*/
STATIC uint
xfs_efi_item_trylock(xfs_efi_log_item_t *efip)
{
	return XFS_ITEM_PINNED;
}

/*
 * Efi items have no locking, so just return.
 */
/*ARGSUSED*/
STATIC void
xfs_efi_item_unlock(xfs_efi_log_item_t *efip)
{
	if (efip->efi_item.li_flags & XFS_LI_ABORTED)
		xfs_efi_item_free(efip);
	return;
}

/*
 * The EFI is logged only once and cannot be moved in the log, so
 * simply return the lsn at which it's been logged.  The canceled
 * flag is not paid any attention here.  Checking for that is delayed
 * until the EFI is unpinned.
 */
/*ARGSUSED*/
STATIC xfs_lsn_t
xfs_efi_item_committed(xfs_efi_log_item_t *efip, xfs_lsn_t lsn)
{
	return lsn;
}

/*
 * There isn't much you can do to push on an efi item.  It is simply
 * stuck waiting for all of its corresponding efd items to be
 * committed to disk.
 */
/*ARGSUSED*/
STATIC void
xfs_efi_item_push(xfs_efi_log_item_t *efip)
{
	return;
}

/*
 * The EFI 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_efi_item_committing(xfs_efi_log_item_t *efip, xfs_lsn_t lsn)
{
	return;
}

/*
 * This is the ops vector shared by all efi log items.
 */
static struct xfs_item_ops xfs_efi_item_ops = {
	.iop_size	= (uint(*)(xfs_log_item_t*))xfs_efi_item_size,
	.iop_format	= (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
					xfs_efi_item_format,
	.iop_pin	= (void(*)(xfs_log_item_t*))xfs_efi_item_pin,
	.iop_unpin	= (void(*)(xfs_log_item_t*, int))xfs_efi_item_unpin,
	.iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t *))
					xfs_efi_item_unpin_remove,
	.iop_trylock	= (uint(*)(xfs_log_item_t*))xfs_efi_item_trylock,
	.iop_unlock	= (void(*)(xfs_log_item_t*))xfs_efi_item_unlock,
	.iop_committed	= (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_efi_item_committed,
	.iop_push	= (void(*)(xfs_log_item_t*))xfs_efi_item_push,
	.iop_pushbuf	= NULL,
	.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
					xfs_efi_item_committing
};


/*
 * Allocate and initialize an efi item with the given number of extents.
 */
xfs_efi_log_item_t *
xfs_efi_init(xfs_mount_t	*mp,
	     uint		nextents)

{
	xfs_efi_log_item_t	*efip;
	uint			size;

	ASSERT(nextents > 0);
	if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
		size = (uint)(sizeof(xfs_efi_log_item_t) +
			((nextents - 1) * sizeof(xfs_extent_t)));
		efip = (xfs_efi_log_item_t*)kmem_zalloc(size, KM_SLEEP);
	} else {
		efip = (xfs_efi_log_item_t*)kmem_zone_zalloc(xfs_efi_zone,
							     KM_SLEEP);
	}

	efip->efi_item.li_type = XFS_LI_EFI;
	efip->efi_item.li_ops = &xfs_efi_item_ops;
	efip->efi_item.li_mountp = mp;
	efip->efi_format.efi_nextents = nextents;
	efip->efi_format.efi_id = (__psint_t)(void*)efip;

	return (efip);
}

/*
 * Copy an EFI format buffer from the given buf, and into the destination
 * EFI format structure.
 * The given buffer can be in 32 bit or 64 bit form (which has different padding),
 * one of which will be the native format for this kernel.
 * It will handle the conversion of formats if necessary.
 */
int
xfs_efi_copy_format(xfs_log_iovec_t *buf, xfs_efi_log_format_t *dst_efi_fmt)
{
	xfs_efi_log_format_t *src_efi_fmt = (xfs_efi_log_format_t *)buf->i_addr;