text: /*
   * 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_bit.h"
  #include "xfs_log.h"
  #include "xfs_inum.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. */
  	mode_t		mode,
  	xfs_nlink_t	nlink,
  	xfs_dev_t	rdev,
  	cred_t		*credp,
  	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;
  	boolean_t	call_again = B_FALSE;
  	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, credp, prid, okalloc,
  			  &ialloc_context, &call_again, &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 (!call_again && (ip == NULL)) {
  		*ipp = NULL;
  		return XFS_ERROR(ENOSPC);
  	}
  
  	/*
  	 * If call_again is set, 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 (call_again) {
  
  		/*
  		 * 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, credp, prid,
  				  okalloc, &ialloc_context, &call_again, &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 ((!call_again) && (ip != NULL));
  
  	} 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_ichgtime(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)
  {
  	if (ip->i_d.di_nlink >= XFS_MAXLINK)
  		return XFS_ERROR(EMLINK);
  	xfs_ichgtime(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;
  }
  