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/*

 * Copyright (c) 2000-2002 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_dir.h"

#include "xfs_dir2.h"

#include "xfs_dmapi.h"

#include "xfs_mount.h"

#include "xfs_bmap_btree.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"

#include "xfs_bmap.h"

#include "xfs_error.h"

#include "xfs_quota.h"

#include "xfs_rw.h"

#include "xfs_itable.h"

#include "xfs_utils.h"

/*

 * xfs_get_dir_entry is used to get a reference to an inode given

 * its parent directory inode and the name of the file.  It does

 * not lock the child inode, and it unlocks the directory before

 * returning.  The directory's generation number is returned for

 * use by a later call to xfs_lock_dir_and_entry.

 */

int

xfs_get_dir_entry(

        vname_t         *dentry,

        xfs_inode_t     **ipp)

{

        vnode_t         *vp;

        bhv_desc_t      *bdp;

        vp = VNAME_TO_VNODE(dentry);

        bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(vp), &xfs_vnodeops);

        if (!bdp) {

                *ipp = NULL;

                return XFS_ERROR(ENOENT);

        }

        VN_HOLD(vp);

        *ipp = XFS_BHVTOI(bdp);

        return 0;

}

int

xfs_dir_lookup_int(

        bhv_desc_t      *dir_bdp,

        uint            lock_mode,

        vname_t         *dentry,

        xfs_ino_t       *inum,

        xfs_inode_t     **ipp)

{

        vnode_t         *dir_vp;

        xfs_inode_t     *dp;

        int             error;

        dir_vp = BHV_TO_VNODE(dir_bdp);

        vn_trace_entry(dir_vp, __FUNCTION__, (inst_t *)__return_address);

        dp = XFS_BHVTOI(dir_bdp);

        error = XFS_DIR_LOOKUP(dp->i_mount, NULL, dp,

                                VNAME(dentry), VNAMELEN(dentry), inum);

        if (!error) {

                /*

                 * Unlock the directory. We do this because we can't

                 * hold the directory lock while doing the vn_get()

                 * in xfs_iget().  Doing so could cause us to hold

                 * a lock while waiting for the inode to finish

                 * being inactive while it's waiting for a log

                 * reservation in the inactive routine.

                 */

                xfs_iunlock(dp, lock_mode);

                error = xfs_iget(dp->i_mount, NULL, *inum, 0, ipp, 0);

                xfs_ilock(dp, lock_mode);

                if (error) {

                        *ipp = NULL;

                } else if ((*ipp)->i_d.di_mode == 0) {

                        /*

                         * The inode has been freed.  Something is

                         * wrong so just get out of here.

                         */

                        xfs_iunlock(dp, lock_mode);

                        xfs_iput_new(*ipp, 0);

                        *ipp = NULL;

                        xfs_ilock(dp, lock_mode);

                        error = XFS_ERROR(ENOENT);

                }

        }

        return error;

}

/*

 * 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,

        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, NULL);

                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->t_mountp, tp);

                        }

                        *tpp = ntp;

                        *ipp = NULL;

                        return code;

                }

                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--;

        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;

        unsigned long           s;

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

        ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1);

        ip->i_d.di_version = XFS_DINODE_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)) {

                s = XFS_SB_LOCK(mp);

                if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {

                        XFS_SB_VERSION_ADDNLINK(&mp->m_sb);

                        XFS_SB_UNLOCK(mp, s);

                        xfs_mod_sb(tp, XFS_SB_VERSIONNUM);

                } else {

                        XFS_SB_UNLOCK(mp, s);

                }

        }

        /* 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++;

        if ((ip->i_d.di_version == XFS_DINODE_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;

}

/*

 * Try to truncate the given file to 0 length.  Currently called

 * only out of xfs_remove when it has to truncate a file to free

 * up space for the remove to proceed.

 */

int

xfs_truncate_file(

        xfs_mount_t     *mp,

        xfs_inode_t     *ip)

{

        xfs_trans_t     *tp;

        int             error;

#ifdef QUOTADEBUG

        /*

         * This is called to truncate the quotainodes too.

         */

        if (XFS_IS_UQUOTA_ON(mp)) {

                if (ip->i_ino != mp->m_sb.sb_uquotino)

                        ASSERT(ip->i_udquot);

        }

        if (XFS_IS_GQUOTA_ON(mp)) {

                if (ip->i_ino != mp->m_sb.sb_gquotino)

                        ASSERT(ip->i_gdquot);

        }

#endif

        /*

         * Make the call to xfs_itruncate_start before starting the

         * transaction, because we cannot make the call while we're

         * in a transaction.

         */

        xfs_ilock(ip, XFS_IOLOCK_EXCL);

        xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, (xfs_fsize_t)0);

        tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE);

        if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,

                                      XFS_TRANS_PERM_LOG_RES,

                                      XFS_ITRUNCATE_LOG_COUNT))) {

                xfs_trans_cancel(tp, 0);

                xfs_iunlock(ip, XFS_IOLOCK_EXCL);

                return error;

        }

        /*

         * Follow the normal truncate locking protocol.  Since we

         * hold the inode in the transaction, we know that it's number

         * of references will stay constant.

         */

        xfs_ilock(ip, XFS_ILOCK_EXCL);

        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);

        xfs_trans_ihold(tp, ip);

        /*

         * Signal a sync xaction.  The only case where that isn't

         * the case is if we're truncating an already unlinked file

         * on a wsync fs.  In that case, we know the blocks can't

         * reappear in the file because the links to file are

         * permanently toast.  Currently, we're always going to

         * want a sync transaction because this code is being

         * called from places where nlink is guaranteed to be 1

         * but I'm leaving the tests in to protect against future

         * changes -- rcc.

         */

        error = xfs_itruncate_finish(&tp, ip, (xfs_fsize_t)0,

                                     XFS_DATA_FORK,

                                     ((ip->i_d.di_nlink != 0 ||

                                       !(mp->m_flags & XFS_MOUNT_WSYNC))

                                      ? 1 : 0));

        if (error) {

                xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |

                                 XFS_TRANS_ABORT);

        } else {

                xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

                error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES,

                                         NULL);

        }

        xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);

        return error;

}