Linux-2.6.12-rc2

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / xfs / xfs_trans_inode.c

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 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.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include "xfs.h"
#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_attr_sf.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode_item.h"
#include "xfs_inode.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 and lock the inode for the caller if it is not already
 * locked within the given transaction.  If it is already locked
 * within the transaction, just increment its lock recursion count
 * and return a pointer to it.
 *
 * For an inode to be locked in a transaction, the inode lock, as
 * opposed to the io lock, must be taken exclusively.  This ensures
 * that the inode can be involved in only 1 transaction at a time.
 * Lock recursion is handled on the io lock, but only for lock modes
 * of equal or lesser strength.  That is, you can recur on the io lock
 * held EXCL with a SHARED request but not vice versa.  Also, if
 * the inode is already a part of the transaction then you cannot
 * go from not holding the io lock to having it EXCL or SHARED.
 *
 * Use the inode cache routine xfs_inode_incore() to find the inode
 * if it is already owned by this transaction.
 *
 * If we don't already own the inode, use xfs_iget() to get it.
 * Since the inode log item structure is embedded in the incore
 * inode structure and is initialized when the inode is brought
 * into memory, there is nothing to do with it here.
 *
 * If the given transaction pointer is NULL, just call xfs_iget().
 * This simplifies code which must handle both cases.
 */
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;
        xfs_inode_t             *ip;
        xfs_inode_log_item_t    *iip;

        /*
         * If the transaction pointer is NULL, just call the normal
         * xfs_iget().
         */
        if (tp == NULL)
                return xfs_iget(mp, NULL, ino, flags, lock_flags, ipp, 0);

        /*
         * If we find the inode in core with this transaction
         * pointer in its i_transp field, then we know we already
         * have it locked.  In this case we just increment the lock
         * recursion count and return the inode to the caller.
         * Assert that the inode is already locked in the mode requested
         * by the caller.  We cannot do lock promotions yet, so
         * die if someone gets this wrong.
         */
        if ((ip = xfs_inode_incore(tp->t_mountp, ino, tp)) != NULL) {
                /*
                 * Make sure that the inode lock is held EXCL and
                 * that the io lock is never upgraded when the inode
                 * is already a part of the transaction.
                 */
                ASSERT(ip->i_itemp != NULL);
                ASSERT(lock_flags & XFS_ILOCK_EXCL);
                ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
                ASSERT((!(lock_flags & XFS_IOLOCK_EXCL)) ||
                       ismrlocked(&ip->i_iolock, MR_UPDATE));
                ASSERT((!(lock_flags & XFS_IOLOCK_EXCL)) ||
                       (ip->i_itemp->ili_flags & XFS_ILI_IOLOCKED_EXCL));
                ASSERT((!(lock_flags & XFS_IOLOCK_SHARED)) ||
                       ismrlocked(&ip->i_iolock, (MR_UPDATE | MR_ACCESS)));
                ASSERT((!(lock_flags & XFS_IOLOCK_SHARED)) ||
                       (ip->i_itemp->ili_flags & XFS_ILI_IOLOCKED_ANY));

                if (lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) {
                        ip->i_itemp->ili_iolock_recur++;
                }
                if (lock_flags & XFS_ILOCK_EXCL) {
                        ip->i_itemp->ili_ilock_recur++;
                }
                *ipp = ip;
                return 0;
        }

        ASSERT(lock_flags & XFS_ILOCK_EXCL);
        error = xfs_iget(tp->t_mountp, tp, ino, flags, lock_flags, &ip, 0);
        if (error) {
                return error;
        }
        ASSERT(ip != NULL);

        /*
         * Get a log_item_desc to point at the new item.
         */
        if (ip->i_itemp == NULL)
                xfs_inode_item_init(ip, mp);
        iip = ip->i_itemp;
        (void) xfs_trans_add_item(tp, (xfs_log_item_t *)(iip));

        xfs_trans_inode_broot_debug(ip);

        /*
         * If the IO lock has been acquired, mark that in
         * the inode log item so we'll know to unlock it
         * when the transaction commits.
         */
        ASSERT(iip->ili_flags == 0);
        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()
         * above.
         */
        ip->i_transp = tp;

        *ipp = ip;
        return 0;
}

/*
 * 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(ismrlocked(&ip->i_lock, MR_UPDATE));
        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);
        ASSERT(iip->ili_ilock_recur == 0);
        ASSERT(iip->ili_iolock_recur == 0);

        /*
         * Get a log_item_desc to point at the new item.
         */
        (void) xfs_trans_add_item(tp, (xfs_log_item_t*)(iip));

        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(ismrlocked(&ip->i_lock, MR_UPDATE));

        ip->i_itemp->ili_flags |= XFS_ILI_HOLD;
}

/*
 * Cancel the previous inode hold request made on this inode
 * for this transaction.
 */
/*ARGSUSED*/
void
xfs_trans_ihold_release(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip)
{
        ASSERT(ip->i_transp == tp);
        ASSERT(ip->i_itemp != NULL);
        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
        ASSERT(ip->i_itemp->ili_flags & XFS_ILI_HOLD);

        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)
{
        xfs_log_item_desc_t     *lidp;

        ASSERT(ip->i_transp == tp);
        ASSERT(ip->i_itemp != NULL);
        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));

        lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)(ip->i_itemp));
        ASSERT(lidp != NULL);

        tp->t_flags |= XFS_TRANS_DIRTY;
        lidp->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 coorination 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);
                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