linux/fs/xfs/xfs_trans_inode.c
Christoph Hellwig e98c414f9a xfs: simplify log item descriptor tracking
Currently we track log item descriptor belonging to a transaction using a
complex opencoded chunk allocator.  This code has been there since day one
and seems to work around the lack of an efficient slab allocator.

This patch replaces it with dynamically allocated log item descriptors
from a dedicated slab pool, linked to the transaction by a linked list.

This allows to greatly simplify the log item descriptor tracking to the
point where it's just a couple hundred lines in xfs_trans.c instead of
a separate file.  The external API has also been simplified while we're
at it - the xfs_trans_add_item and xfs_trans_del_item functions to add/
delete items from a transaction have been simplified to the bare minium,
and the xfs_trans_find_item function is replaced with a direct dereference
of the li_desc field.  All debug code walking the list of log items in
a transaction is down to a simple list_for_each_entry.

Note that we could easily use a singly linked list here instead of the
double linked list from list.h as the fastpath only does deletion from
sequential traversal.  But given that we don't have one available as
a library function yet I use the list.h functions for simplicity.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-07-26 13:16:34 -05:00

195 lines
4.8 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_bit.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_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_trans_priv.h"
#include "xfs_inode_item.h"
#ifdef XFS_TRANS_DEBUG
STATIC void
xfs_trans_inode_broot_debug(
xfs_inode_t *ip);
#else
#define xfs_trans_inode_broot_debug(ip)
#endif
/*
* Get an inode and join it to the transaction.
*/
int
xfs_trans_iget(
xfs_mount_t *mp,
xfs_trans_t *tp,
xfs_ino_t ino,
uint flags,
uint lock_flags,
xfs_inode_t **ipp)
{
int error;
error = xfs_iget(mp, tp, ino, flags, lock_flags, ipp);
if (!error && tp)
xfs_trans_ijoin(tp, *ipp, lock_flags);
return error;
}
/*
* Add the locked inode to the transaction.
* The inode must be locked, and it cannot be associated with any
* transaction. The caller must specify the locks already held
* on the inode.
*/
void
xfs_trans_ijoin(
xfs_trans_t *tp,
xfs_inode_t *ip,
uint lock_flags)
{
xfs_inode_log_item_t *iip;
ASSERT(ip->i_transp == NULL);
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
ASSERT(lock_flags & XFS_ILOCK_EXCL);
if (ip->i_itemp == NULL)
xfs_inode_item_init(ip, ip->i_mount);
iip = ip->i_itemp;
ASSERT(iip->ili_flags == 0);
/*
* Get a log_item_desc to point at the new item.
*/
xfs_trans_add_item(tp, &iip->ili_item);
xfs_trans_inode_broot_debug(ip);
/*
* If the IO lock is already held, mark that in the inode log item.
*/
if (lock_flags & XFS_IOLOCK_EXCL) {
iip->ili_flags |= XFS_ILI_IOLOCKED_EXCL;
} else if (lock_flags & XFS_IOLOCK_SHARED) {
iip->ili_flags |= XFS_ILI_IOLOCKED_SHARED;
}
/*
* Initialize i_transp so we can find it with xfs_inode_incore()
* in xfs_trans_iget() above.
*/
ip->i_transp = tp;
}
/*
* Mark the inode as not needing to be unlocked when the inode item's
* IOP_UNLOCK() routine is called. The inode must already be locked
* and associated with the given transaction.
*/
/*ARGSUSED*/
void
xfs_trans_ihold(
xfs_trans_t *tp,
xfs_inode_t *ip)
{
ASSERT(ip->i_transp == tp);
ASSERT(ip->i_itemp != NULL);
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
ip->i_itemp->ili_flags |= XFS_ILI_HOLD;
}
/*
* This is called to mark the fields indicated in fieldmask as needing
* to be logged when the transaction is committed. The inode must
* already be associated with the given transaction.
*
* The values for fieldmask are defined in xfs_inode_item.h. We always
* log all of the core inode if any of it has changed, and we always log
* all of the inline data/extents/b-tree root if any of them has changed.
*/
void
xfs_trans_log_inode(
xfs_trans_t *tp,
xfs_inode_t *ip,
uint flags)
{
ASSERT(ip->i_transp == tp);
ASSERT(ip->i_itemp != NULL);
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
tp->t_flags |= XFS_TRANS_DIRTY;
ip->i_itemp->ili_item.li_desc->lid_flags |= XFS_LID_DIRTY;
/*
* Always OR in the bits from the ili_last_fields field.
* This is to coordinate with the xfs_iflush() and xfs_iflush_done()
* routines in the eventual clearing of the ilf_fields bits.
* See the big comment in xfs_iflush() for an explanation of
* this coordination mechanism.
*/
flags |= ip->i_itemp->ili_last_fields;
ip->i_itemp->ili_format.ilf_fields |= flags;
}
#ifdef XFS_TRANS_DEBUG
/*
* Keep track of the state of the inode btree root to make sure we
* log it properly.
*/
STATIC void
xfs_trans_inode_broot_debug(
xfs_inode_t *ip)
{
xfs_inode_log_item_t *iip;
ASSERT(ip->i_itemp != NULL);
iip = ip->i_itemp;
if (iip->ili_root_size != 0) {
ASSERT(iip->ili_orig_root != NULL);
kmem_free(iip->ili_orig_root);
iip->ili_root_size = 0;
iip->ili_orig_root = NULL;
}
if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
ASSERT((ip->i_df.if_broot != NULL) &&
(ip->i_df.if_broot_bytes > 0));
iip->ili_root_size = ip->i_df.if_broot_bytes;
iip->ili_orig_root =
(char*)kmem_alloc(iip->ili_root_size, KM_SLEEP);
memcpy(iip->ili_orig_root, (char*)(ip->i_df.if_broot),
iip->ili_root_size);
}
}
#endif