linux/fs/xfs/xfs_trans_extfree.c
Dave Chinner b199c8a4ba xfs: Pull EFI/EFD handling out from under the AIL lock
EFI/EFD interactions are protected from races by the AIL lock. They
are the only type of log items that require the the AIL lock to
serialise internal state, so they need to be separated from the AIL
lock before we can do bulk insert operations on the AIL.

To acheive this, convert the counter of the number of extents in the
EFI to an atomic so it can be safely manipulated by EFD processing
without locks. Also, convert the EFI state flag manipulations to use
atomic bit operations so no locks are needed to record state
changes. Finally, use the state bits to determine when it is safe to
free the EFI and clean up the code to do this neatly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20 11:59:49 +11:00

134 lines
3.5 KiB
C

/*
* Copyright (c) 2000,2005 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_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_extfree_item.h"
/*
* This routine is called to allocate an "extent free intention"
* log item that will hold nextents worth of extents. The
* caller must use all nextents extents, because we are not
* flexible about this at all.
*/
xfs_efi_log_item_t *
xfs_trans_get_efi(xfs_trans_t *tp,
uint nextents)
{
xfs_efi_log_item_t *efip;
ASSERT(tp != NULL);
ASSERT(nextents > 0);
efip = xfs_efi_init(tp->t_mountp, nextents);
ASSERT(efip != NULL);
/*
* Get a log_item_desc to point at the new item.
*/
xfs_trans_add_item(tp, &efip->efi_item);
return efip;
}
/*
* This routine is called to indicate that the described
* extent is to be logged as needing to be freed. It should
* be called once for each extent to be freed.
*/
void
xfs_trans_log_efi_extent(xfs_trans_t *tp,
xfs_efi_log_item_t *efip,
xfs_fsblock_t start_block,
xfs_extlen_t ext_len)
{
uint next_extent;
xfs_extent_t *extp;
tp->t_flags |= XFS_TRANS_DIRTY;
efip->efi_item.li_desc->lid_flags |= XFS_LID_DIRTY;
/*
* atomic_inc_return gives us the value after the increment;
* we want to use it as an array index so we need to subtract 1 from
* it.
*/
next_extent = atomic_inc_return(&efip->efi_next_extent) - 1;
ASSERT(next_extent < efip->efi_format.efi_nextents);
extp = &(efip->efi_format.efi_extents[next_extent]);
extp->ext_start = start_block;
extp->ext_len = ext_len;
}
/*
* This routine is called to allocate an "extent free done"
* log item that will hold nextents worth of extents. The
* caller must use all nextents extents, because we are not
* flexible about this at all.
*/
xfs_efd_log_item_t *
xfs_trans_get_efd(xfs_trans_t *tp,
xfs_efi_log_item_t *efip,
uint nextents)
{
xfs_efd_log_item_t *efdp;
ASSERT(tp != NULL);
ASSERT(nextents > 0);
efdp = xfs_efd_init(tp->t_mountp, efip, nextents);
ASSERT(efdp != NULL);
/*
* Get a log_item_desc to point at the new item.
*/
xfs_trans_add_item(tp, &efdp->efd_item);
return efdp;
}
/*
* This routine is called to indicate that the described
* extent is to be logged as having been freed. It should
* be called once for each extent freed.
*/
void
xfs_trans_log_efd_extent(xfs_trans_t *tp,
xfs_efd_log_item_t *efdp,
xfs_fsblock_t start_block,
xfs_extlen_t ext_len)
{
uint next_extent;
xfs_extent_t *extp;
tp->t_flags |= XFS_TRANS_DIRTY;
efdp->efd_item.li_desc->lid_flags |= XFS_LID_DIRTY;
next_extent = efdp->efd_next_extent;
ASSERT(next_extent < efdp->efd_format.efd_nextents);
extp = &(efdp->efd_format.efd_extents[next_extent]);
extp->ext_start = start_block;
extp->ext_len = ext_len;
efdp->efd_next_extent++;
}