/*

   * Copyright (c) 2000-2003 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_bit.h"

  #include "xfs_log.h"

  #include "xfs_inum.h"

  #include "xfs_trans.h"
  #include "xfs_sb.h"
  #include "xfs_ag.h"

  #include "xfs_alloc.h"

  #include "xfs_quota.h"
  #include "xfs_mount.h"

  #include "xfs_bmap_btree.h"

  #include "xfs_inode.h"
  #include "xfs_bmap.h"

  #include "xfs_rtalloc.h"
  #include "xfs_error.h"
  #include "xfs_itable.h"

  #include "xfs_attr.h"
  #include "xfs_buf_item.h"
  #include "xfs_trans_priv.h"

  #include "xfs_qm.h"

  static inline struct xfs_dq_logitem *DQUOT_ITEM(struct xfs_log_item *lip)
  {
  	return container_of(lip, struct xfs_dq_logitem, qli_item);
  }

  /*
   * returns the number of iovecs needed to log the given dquot item.
   */

  STATIC uint
  xfs_qm_dquot_logitem_size(

  	struct xfs_log_item	*lip)

  {
  	/*
  	 * we need only two iovecs, one for the format, one for the real thing
  	 */

  	return 2;

  }
  
  /*
   * fills in the vector of log iovecs for the given dquot log item.
   */
  STATIC void
  xfs_qm_dquot_logitem_format(

  	struct xfs_log_item	*lip,
  	struct xfs_log_iovec	*logvec)

  {

  	struct xfs_dq_logitem	*qlip = DQUOT_ITEM(lip);

  	logvec->i_addr = &qlip->qli_format;

  	logvec->i_len  = sizeof(xfs_dq_logformat_t);

  	logvec->i_type = XLOG_REG_TYPE_QFORMAT;

  	logvec++;

  	logvec->i_addr = &qlip->qli_dquot->q_core;

  	logvec->i_len  = sizeof(xfs_disk_dquot_t);

  	logvec->i_type = XLOG_REG_TYPE_DQUOT;

  	qlip->qli_format.qlf_size = 2;

  
  }
  
  /*
   * Increment the pin count of the given dquot.

   */
  STATIC void
  xfs_qm_dquot_logitem_pin(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;

  	ASSERT(XFS_DQ_IS_LOCKED(dqp));

  	atomic_inc(&dqp->q_pincount);

  }
  
  /*
   * Decrement the pin count of the given dquot, and wake up
   * anyone in xfs_dqwait_unpin() if the count goes to 0.	 The

   * dquot must have been previously pinned with a call to
   * xfs_qm_dquot_logitem_pin().

   */

  STATIC void
  xfs_qm_dquot_logitem_unpin(

  	struct xfs_log_item	*lip,

  	int			remove)

  {

  	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;

  	ASSERT(atomic_read(&dqp->q_pincount) > 0);
  	if (atomic_dec_and_test(&dqp->q_pincount))
  		wake_up(&dqp->q_pinwait);

  }

  /*
   * Given the logitem, this writes the corresponding dquot entry to disk
   * asynchronously. This is called with the dquot entry securely locked;
   * we simply get xfs_qm_dqflush() to do the work, and unlock the dquot
   * at the end.
   */
  STATIC void
  xfs_qm_dquot_logitem_push(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;
  	int			error;

  
  	ASSERT(XFS_DQ_IS_LOCKED(dqp));

  	ASSERT(!completion_done(&dqp->q_flush));

  
  	/*
  	 * Since we were able to lock the dquot's flush lock and
  	 * we found it on the AIL, the dquot must be dirty.  This
  	 * is because the dquot is removed from the AIL while still
  	 * holding the flush lock in xfs_dqflush_done().  Thus, if
  	 * we found it in the AIL and were able to obtain the flush
  	 * lock without sleeping, then there must not have been
  	 * anyone in the process of flushing the dquot.
  	 */

  	error = xfs_qm_dqflush(dqp, SYNC_TRYLOCK);

  	if (error)

  		xfs_warn(dqp->q_mount, "%s: push error %d on dqp %p",
  			__func__, error, dqp);

  	xfs_dqunlock(dqp);
  }

  STATIC xfs_lsn_t
  xfs_qm_dquot_logitem_committed(

  	struct xfs_log_item	*lip,

  	xfs_lsn_t		lsn)
  {
  	/*
  	 * We always re-log the entire dquot when it becomes dirty,
  	 * so, the latest copy _is_ the only one that matters.
  	 */

  	return lsn;

  }

  /*
   * This is called to wait for the given dquot to be unpinned.
   * Most of these pin/unpin routines are plagiarized from inode code.
   */
  void
  xfs_qm_dqunpin_wait(

  	struct xfs_dquot	*dqp)

  {

  	ASSERT(XFS_DQ_IS_LOCKED(dqp));

  	if (atomic_read(&dqp->q_pincount) == 0)

  		return;

  
  	/*
  	 * Give the log a push so we don't wait here too long.
  	 */

  	xfs_log_force(dqp->q_mount, 0);

  	wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0));

  }
  
  /*
   * This is called when IOP_TRYLOCK returns XFS_ITEM_PUSHBUF to indicate that
   * the dquot is locked by us, but the flush lock isn't. So, here we are
   * going to see if the relevant dquot buffer is incore, waiting on DELWRI.
   * If so, we want to push it out to help us take this item off the AIL as soon
   * as possible.
   *

   * We must not be holding the AIL lock at this point. Calling incore() to
   * search the buffer cache can be a time consuming thing, and AIL lock is a

   * spinlock.
   */

  STATIC bool

  xfs_qm_dquot_logitem_pushbuf(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_dq_logitem	*qlip = DQUOT_ITEM(lip);
  	struct xfs_dquot	*dqp = qlip->qli_dquot;
  	struct xfs_buf		*bp;

  	bool			ret = true;

  	ASSERT(XFS_DQ_IS_LOCKED(dqp));
  
  	/*

  	 * If flushlock isn't locked anymore, chances are that the
  	 * inode flush completed and the inode was taken off the AIL.
  	 * So, just get out.
  	 */

  	if (completion_done(&dqp->q_flush) ||
  	    !(lip->li_flags & XFS_LI_IN_AIL)) {

  		xfs_dqunlock(dqp);

  		return true;

  	}

  
  	bp = xfs_incore(dqp->q_mount->m_ddev_targp, qlip->qli_format.qlf_blkno,
  			dqp->q_mount->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);

  	xfs_dqunlock(dqp);
  	if (!bp)

  		return true;

  	if (XFS_BUF_ISDELAYWRITE(bp))
  		xfs_buf_delwri_promote(bp);

  	if (xfs_buf_ispinned(bp))
  		ret = false;

  	xfs_buf_relse(bp);

  	return ret;

  }
  
  /*
   * This is called to attempt to lock the dquot associated with this
   * dquot log item.  Don't sleep on the dquot lock or the flush lock.
   * If the flush lock is already held, indicating that the dquot has
   * been or is in the process of being flushed, then see if we can
   * find the dquot's buffer in the buffer cache without sleeping.  If
   * we can and it is marked delayed write, then we want to send it out.
   * We delay doing so until the push routine, though, to avoid sleeping
   * in any device strategy routines.
   */
  STATIC uint
  xfs_qm_dquot_logitem_trylock(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;

  	if (atomic_read(&dqp->q_pincount) > 0)

  		return XFS_ITEM_PINNED;

  	if (!xfs_dqlock_nowait(dqp))

  		return XFS_ITEM_LOCKED;

  	if (!xfs_dqflock_nowait(dqp)) {

  		/*

  		 * dquot has already been flushed to the backing buffer,
  		 * leave it locked, pushbuf routine will unlock it.

  		 */

  		return XFS_ITEM_PUSHBUF;

  	}

  	ASSERT(lip->li_flags & XFS_LI_IN_AIL);

  	return XFS_ITEM_SUCCESS;

  }

  /*
   * Unlock the dquot associated with the log item.
   * Clear the fields of the dquot and dquot log item that
   * are specific to the current transaction.  If the
   * hold flags is set, do not unlock the dquot.
   */
  STATIC void
  xfs_qm_dquot_logitem_unlock(

  	struct xfs_log_item	*lip)

  {

  	struct xfs_dquot	*dqp = DQUOT_ITEM(lip)->qli_dquot;

  	ASSERT(XFS_DQ_IS_LOCKED(dqp));
  
  	/*
  	 * Clear the transaction pointer in the dquot
  	 */
  	dqp->q_transp = NULL;
  
  	/*
  	 * dquots are never 'held' from getting unlocked at the end of
  	 * a transaction.  Their locking and unlocking is hidden inside the
  	 * transaction layer, within trans_commit. Hence, no LI_HOLD flag
  	 * for the logitem.
  	 */
  	xfs_dqunlock(dqp);
  }

  /*

   * this needs to stamp an lsn into the dquot, I think.
   * rpc's that look at user dquot's would then have to
   * push on the dependency recorded in the dquot
   */

  STATIC void
  xfs_qm_dquot_logitem_committing(

  	struct xfs_log_item	*lip,

  	xfs_lsn_t		lsn)
  {

  }

  /*
   * This is the ops vector for dquots
   */

  static const struct xfs_item_ops xfs_dquot_item_ops = {

  	.iop_size	= xfs_qm_dquot_logitem_size,
  	.iop_format	= xfs_qm_dquot_logitem_format,
  	.iop_pin	= xfs_qm_dquot_logitem_pin,
  	.iop_unpin	= xfs_qm_dquot_logitem_unpin,
  	.iop_trylock	= xfs_qm_dquot_logitem_trylock,
  	.iop_unlock	= xfs_qm_dquot_logitem_unlock,
  	.iop_committed	= xfs_qm_dquot_logitem_committed,
  	.iop_push	= xfs_qm_dquot_logitem_push,
  	.iop_pushbuf	= xfs_qm_dquot_logitem_pushbuf,
  	.iop_committing = xfs_qm_dquot_logitem_committing

  };
  
  /*
   * Initialize the dquot log item for a newly allocated dquot.
   * The dquot isn't locked at this point, but it isn't on any of the lists
   * either, so we don't care.
   */
  void
  xfs_qm_dquot_logitem_init(

  	struct xfs_dquot	*dqp)

  {

  	struct xfs_dq_logitem	*lp = &dqp->q_logitem;

  	xfs_log_item_init(dqp->q_mount, &lp->qli_item, XFS_LI_DQUOT,
  					&xfs_dquot_item_ops);

  	lp->qli_dquot = dqp;
  	lp->qli_format.qlf_type = XFS_LI_DQUOT;

  	lp->qli_format.qlf_id = be32_to_cpu(dqp->q_core.d_id);

  	lp->qli_format.qlf_blkno = dqp->q_blkno;
  	lp->qli_format.qlf_len = 1;
  	/*
  	 * This is just the offset of this dquot within its buffer
  	 * (which is currently 1 FSB and probably won't change).
  	 * Hence 32 bits for this offset should be just fine.
  	 * Alternatively, we can store (bufoffset / sizeof(xfs_dqblk_t))
  	 * here, and recompute it at recovery time.
  	 */
  	lp->qli_format.qlf_boffset = (__uint32_t)dqp->q_bufoffset;
  }
  
  /*------------------  QUOTAOFF LOG ITEMS  -------------------*/

  static inline struct xfs_qoff_logitem *QOFF_ITEM(struct xfs_log_item *lip)
  {
  	return container_of(lip, struct xfs_qoff_logitem, qql_item);
  }

  /*
   * This returns the number of iovecs needed to log the given quotaoff item.
   * We only need 1 iovec for an quotaoff item.  It just logs the
   * quotaoff_log_format structure.
   */

  STATIC uint

  xfs_qm_qoff_logitem_size(
  	struct xfs_log_item	*lip)

  {

  	return 1;

  }
  
  /*
   * This is called to fill in the vector of log iovecs for the
   * given quotaoff log item. We use only 1 iovec, and we point that
   * at the quotaoff_log_format structure embedded in the quotaoff item.
   * It is at this point that we assert that all of the extent
   * slots in the quotaoff item have been filled.
   */
  STATIC void

  xfs_qm_qoff_logitem_format(
  	struct xfs_log_item	*lip,
  	struct xfs_log_iovec	*log_vector)

  {

  	struct xfs_qoff_logitem	*qflip = QOFF_ITEM(lip);

  	ASSERT(qflip->qql_format.qf_type == XFS_LI_QUOTAOFF);

  	log_vector->i_addr = &qflip->qql_format;

  	log_vector->i_len = sizeof(xfs_qoff_logitem_t);

  	log_vector->i_type = XLOG_REG_TYPE_QUOTAOFF;

  	qflip->qql_format.qf_size = 1;

  }

  /*
   * Pinning has no meaning for an quotaoff item, so just return.
   */

  STATIC void

  xfs_qm_qoff_logitem_pin(
  	struct xfs_log_item	*lip)

  {

  }

  /*
   * Since pinning has no meaning for an quotaoff item, unpinning does
   * not either.
   */

  STATIC void

  xfs_qm_qoff_logitem_unpin(
  	struct xfs_log_item	*lip,
  	int			remove)

  {

  }
  
  /*
   * Quotaoff items have no locking, so just return success.
   */

  STATIC uint

  xfs_qm_qoff_logitem_trylock(
  	struct xfs_log_item	*lip)

  {
  	return XFS_ITEM_LOCKED;
  }
  
  /*
   * Quotaoff items have no locking or pushing, so return failure
   * so that the caller doesn't bother with us.
   */

  STATIC void

  xfs_qm_qoff_logitem_unlock(
  	struct xfs_log_item	*lip)

  {

  }
  
  /*
   * The quotaoff-start-item is logged only once and cannot be moved in the log,
   * so simply return the lsn at which it's been logged.
   */

  STATIC xfs_lsn_t

  xfs_qm_qoff_logitem_committed(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)

  {

  	return lsn;

  }
  
  /*

   * There isn't much you can do to push on an quotaoff item.  It is simply
   * stuck waiting for the log to be flushed to disk.
   */

  STATIC void

  xfs_qm_qoff_logitem_push(
  	struct xfs_log_item	*lip)

  {

  }

  STATIC xfs_lsn_t
  xfs_qm_qoffend_logitem_committed(

  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn)

  {

  	struct xfs_qoff_logitem	*qfe = QOFF_ITEM(lip);
  	struct xfs_qoff_logitem	*qfs = qfe->qql_start_lip;
  	struct xfs_ail		*ailp = qfs->qql_item.li_ailp;

  	/*
  	 * Delete the qoff-start logitem from the AIL.

  	 * xfs_trans_ail_delete() drops the AIL lock.

  	 */

  	spin_lock(&ailp->xa_lock);

  	xfs_trans_ail_delete(ailp, (xfs_log_item_t *)qfs);

  	kmem_free(qfs);
  	kmem_free(qfe);

  	return (xfs_lsn_t)-1;
  }
  
  /*
   * XXX rcc - don't know quite what to do with this.  I think we can
   * just ignore it.  The only time that isn't the case is if we allow
   * the client to somehow see that quotas have been turned off in which
   * we can't allow that to get back until the quotaoff hits the disk.
   * So how would that happen?  Also, do we need different routines for
   * quotaoff start and quotaoff end?  I suspect the answer is yes but
   * to be sure, I need to look at the recovery code and see how quota off
   * recovery is handled (do we roll forward or back or do something else).
   * If we roll forwards or backwards, then we need two separate routines,
   * one that does nothing and one that stamps in the lsn that matters
   * (truly makes the quotaoff irrevocable).  If we do something else,
   * then maybe we don't need two.
   */

  STATIC void

  xfs_qm_qoff_logitem_committing(
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		commit_lsn)

  {

  }

  static const struct xfs_item_ops xfs_qm_qoffend_logitem_ops = {

  	.iop_size	= xfs_qm_qoff_logitem_size,
  	.iop_format	= xfs_qm_qoff_logitem_format,
  	.iop_pin	= xfs_qm_qoff_logitem_pin,
  	.iop_unpin	= xfs_qm_qoff_logitem_unpin,
  	.iop_trylock	= xfs_qm_qoff_logitem_trylock,
  	.iop_unlock	= xfs_qm_qoff_logitem_unlock,
  	.iop_committed	= xfs_qm_qoffend_logitem_committed,
  	.iop_push	= xfs_qm_qoff_logitem_push,
  	.iop_committing = xfs_qm_qoff_logitem_committing

  };
  
  /*
   * This is the ops vector shared by all quotaoff-start log items.
   */

  static const struct xfs_item_ops xfs_qm_qoff_logitem_ops = {

  	.iop_size	= xfs_qm_qoff_logitem_size,
  	.iop_format	= xfs_qm_qoff_logitem_format,
  	.iop_pin	= xfs_qm_qoff_logitem_pin,
  	.iop_unpin	= xfs_qm_qoff_logitem_unpin,
  	.iop_trylock	= xfs_qm_qoff_logitem_trylock,
  	.iop_unlock	= xfs_qm_qoff_logitem_unlock,
  	.iop_committed	= xfs_qm_qoff_logitem_committed,
  	.iop_push	= xfs_qm_qoff_logitem_push,
  	.iop_committing = xfs_qm_qoff_logitem_committing

  };
  
  /*
   * Allocate and initialize an quotaoff item of the correct quota type(s).
   */

  struct xfs_qoff_logitem *

  xfs_qm_qoff_logitem_init(

  	struct xfs_mount	*mp,
  	struct xfs_qoff_logitem	*start,
  	uint			flags)

  {

  	struct xfs_qoff_logitem	*qf;

  	qf = kmem_zalloc(sizeof(struct xfs_qoff_logitem), KM_SLEEP);

  	xfs_log_item_init(mp, &qf->qql_item, XFS_LI_QUOTAOFF, start ?
  			&xfs_qm_qoffend_logitem_ops : &xfs_qm_qoff_logitem_ops);

  	qf->qql_item.li_mountp = mp;
  	qf->qql_format.qf_type = XFS_LI_QUOTAOFF;
  	qf->qql_format.qf_flags = flags;
  	qf->qql_start_lip = start;

  	return qf;

  }