/*
 * Copyright (c) 2000-2002,2005 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_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_itable.h"
#include "xfs_utils.h"


/*
 * Allocates a new inode from disk and return a pointer to the
 * incore copy. This routine will internally commit the current
 * transaction and allocate a new one if the Space Manager needed
 * to do an allocation to replenish the inode free-list.
 *
 * This routine is designed to be called from xfs_create and
 * xfs_create_dir.
 *
 */
int
xfs_dir_ialloc(
        xfs_trans_t     **tpp,          /* input: current transaction;
                                           output: may be a new transaction. */
        xfs_inode_t     *dp,            /* directory within whose allocate
                                           the inode. */
        umode_t         mode,
        xfs_nlink_t     nlink,
        xfs_dev_t       rdev,
        prid_t          prid,           /* project id */
        int             okalloc,        /* ok to allocate new space */
        xfs_inode_t     **ipp,          /* pointer to inode; it will be
                                           locked. */
        int             *committed)

{
        xfs_trans_t     *tp;
        xfs_trans_t     *ntp;
        xfs_inode_t     *ip;
        xfs_buf_t       *ialloc_context = NULL;
        int             code;
        uint            log_res;
        uint            log_count;
        void            *dqinfo;
        uint            tflags;

        tp = *tpp;
        ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);

        /*
         * xfs_ialloc will return a pointer to an incore inode if
         * the Space Manager has an available inode on the free
         * list. Otherwise, it will do an allocation and replenish
         * the freelist.  Since we can only do one allocation per
         * transaction without deadlocks, we will need to commit the
         * current transaction and start a new one.  We will then
         * need to call xfs_ialloc again to get the inode.
         *
         * If xfs_ialloc did an allocation to replenish the freelist,
         * it returns the bp containing the head of the freelist as
         * ialloc_context. We will hold a lock on it across the
         * transaction commit so that no other process can steal
         * the inode(s) that we've just allocated.
         */
        code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, okalloc,
                          &ialloc_context, &ip);

        /*
         * Return an error if we were unable to allocate a new inode.
         * This should only happen if we run out of space on disk or
         * encounter a disk error.
         */
        if (code) {
                *ipp = NULL;
                return code;
        }
        if (!ialloc_context && !ip) {
                *ipp = NULL;
                return XFS_ERROR(ENOSPC);
        }

        /*
         * If the AGI buffer is non-NULL, then we were unable to get an
         * inode in one operation.  We need to commit the current
         * transaction and call xfs_ialloc() again.  It is guaranteed
         * to succeed the second time.
         */
        if (ialloc_context) {
                /*
                 * Normally, xfs_trans_commit releases all the locks.
                 * We call bhold to hang on to the ialloc_context across
                 * the commit.  Holding this buffer prevents any other
                 * processes from doing any allocations in this
                 * allocation group.
                 */
                xfs_trans_bhold(tp, ialloc_context);
                /*
                 * Save the log reservation so we can use
                 * them in the next transaction.
                 */
                log_res = xfs_trans_get_log_res(tp);
                log_count = xfs_trans_get_log_count(tp);

                /*
                 * We want the quota changes to be associated with the next
                 * transaction, NOT this one. So, detach the dqinfo from this
                 * and attach it to the next transaction.
                 */
                dqinfo = NULL;
                tflags = 0;
                if (tp->t_dqinfo) {
                        dqinfo = (void *)tp->t_dqinfo;
                        tp->t_dqinfo = NULL;
                        tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
                        tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
                }

                ntp = xfs_trans_dup(tp);
                code = xfs_trans_commit(tp, 0);
                tp = ntp;
                if (committed != NULL) {
                        *committed = 1;
                }
                /*
                 * If we get an error during the commit processing,
                 * release the buffer that is still held and return
                 * to the caller.
                 */
                if (code) {
                        xfs_buf_relse(ialloc_context);
                        if (dqinfo) {
                                tp->t_dqinfo = dqinfo;
                                xfs_trans_free_dqinfo(tp);
                        }
                        *tpp = ntp;
                        *ipp = NULL;
                        return code;
                }

                /*
                 * transaction commit worked ok so we can drop the extra ticket
                 * reference that we gained in xfs_trans_dup()
                 */
                xfs_log_ticket_put(tp->t_ticket);
                code = xfs_trans_reserve(tp, 0, log_res, 0,
                                         XFS_TRANS_PERM_LOG_RES, log_count);
                /*
                 * Re-attach the quota info that we detached from prev trx.
                 */
                if (dqinfo) {
                        tp->t_dqinfo = dqinfo;
                        tp->t_flags |= tflags;
                }

                if (code) {
                        xfs_buf_relse(ialloc_context);
                        *tpp = ntp;
                        *ipp = NULL;
                        return code;
                }
                xfs_trans_bjoin(tp, ialloc_context);

                /*
                 * Call ialloc again. Since we've locked out all
                 * other allocations in this allocation group,
                 * this call should always succeed.
                 */
                code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
                                  okalloc, &ialloc_context, &ip);

                /*
                 * If we get an error at this point, return to the caller
                 * so that the current transaction can be aborted.
                 */
                if (code) {
                        *tpp = tp;
                        *ipp = NULL;
                        return code;
                }
                ASSERT(!ialloc_context && ip);

        } else {
                if (committed != NULL)
                        *committed = 0;
        }

        *ipp = ip;
        *tpp = tp;

        return 0;
}

/*
 * Decrement the link count on an inode & log the change.
 * If this causes the link count to go to zero, initiate the
 * logging activity required to truncate a file.
 */
int                             /* error */
xfs_droplink(
        xfs_trans_t *tp,
        xfs_inode_t *ip)
{
        int     error;

        xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);

        ASSERT (ip->i_d.di_nlink > 0);
        ip->i_d.di_nlink--;
        drop_nlink(VFS_I(ip));
        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

        error = 0;
        if (ip->i_d.di_nlink == 0) {
                /*
                 * We're dropping the last link to this file.
                 * Move the on-disk inode to the AGI unlinked list.
                 * From xfs_inactive() we will pull the inode from
                 * the list and free it.
                 */
                error = xfs_iunlink(tp, ip);
        }
        return error;
}

/*
 * This gets called when the inode's version needs to be changed from 1 to 2.
 * Currently this happens when the nlink field overflows the old 16-bit value
 * or when chproj is called to change the project for the first time.
 * As a side effect the superblock version will also get rev'd
 * to contain the NLINK bit.
 */
void
xfs_bump_ino_vers2(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip)
{
        xfs_mount_t     *mp;

        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
        ASSERT(ip->i_d.di_version == 1);

        ip->i_d.di_version = 2;
        ip->i_d.di_onlink = 0;
        memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
        mp = tp->t_mountp;
        if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
                spin_lock(&mp->m_sb_lock);
                if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
                        xfs_sb_version_addnlink(&mp->m_sb);
                        spin_unlock(&mp->m_sb_lock);
                        xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
                } else {
                        spin_unlock(&mp->m_sb_lock);
                }
        }
        /* Caller must log the inode */
}

/*
 * Increment the link count on an inode & log the change.
 */
int
xfs_bumplink(
        xfs_trans_t *tp,
        xfs_inode_t *ip)
{
        xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);

        ASSERT(ip->i_d.di_nlink > 0);
        ip->i_d.di_nlink++;
        inc_nlink(VFS_I(ip));
        if ((ip->i_d.di_version == 1) &&
            (ip->i_d.di_nlink > XFS_MAXLINK_1)) {
                /*
                 * The inode has increased its number of links beyond
                 * what can fit in an old format inode.  It now needs
                 * to be converted to a version 2 inode with a 32 bit
                 * link count.  If this is the first inode in the file
                 * system to do this, then we need to bump the superblock
                 * version number as well.
                 */
                xfs_bump_ino_vers2(tp, ip);
        }

        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
        return 0;
}