Beispiel #1
0
/*
 * This is called to free all the memory associated with a dquot
 */
void
xfs_qm_dqdestroy(
	xfs_dquot_t	*dqp)
{
	ASSERT(! XFS_DQ_IS_ON_FREELIST(dqp));

	mutex_destroy(&dqp->q_qlock);
	sv_destroy(&dqp->q_pinwait);

#ifdef XFS_DQUOT_TRACE
	if (dqp->q_trace)
	     ktrace_free(dqp->q_trace);
	dqp->q_trace = NULL;
#endif
	kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
	atomic_dec(&xfs_Gqm->qm_totaldquots);
}
/*
 * Lookup a dquot in the incore dquot hashtable. We keep two separate
 * hashtables for user and group dquots; and, these are global tables
 * inside the XQM, not per-filesystem tables.
 * The hash chain must be locked by caller, and it is left locked
 * on return. Returning dquot is locked.
 */
STATIC int
xfs_qm_dqlookup(
	xfs_mount_t		*mp,
	xfs_dqid_t		id,
	xfs_dqhash_t		*qh,
	xfs_dquot_t		**O_dqpp)
{
	xfs_dquot_t		*dqp;
	uint			flist_locked;
	xfs_dquot_t		*d;

	ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));

	flist_locked = B_FALSE;

	/*
	 * Traverse the hashchain looking for a match
	 */
	for (dqp = qh->qh_next; dqp != NULL; dqp = dqp->HL_NEXT) {
		/*
		 * We already have the hashlock. We don't need the
		 * dqlock to look at the id field of the dquot, since the
		 * id can't be modified without the hashlock anyway.
		 */
		if (be32_to_cpu(dqp->q_core.d_id) == id && dqp->q_mount == mp) {
			xfs_dqtrace_entry(dqp, "DQFOUND BY LOOKUP");
			/*
			 * All in core dquots must be on the dqlist of mp
			 */
			ASSERT(dqp->MPL_PREVP != NULL);

			xfs_dqlock(dqp);
			if (dqp->q_nrefs == 0) {
				ASSERT (XFS_DQ_IS_ON_FREELIST(dqp));
				if (! xfs_qm_freelist_lock_nowait(xfs_Gqm)) {
					xfs_dqtrace_entry(dqp, "DQLOOKUP: WANT");

					/*
					 * We may have raced with dqreclaim_one()
					 * (and lost). So, flag that we don't
					 * want the dquot to be reclaimed.
					 */
					dqp->dq_flags |= XFS_DQ_WANT;
					xfs_dqunlock(dqp);
					xfs_qm_freelist_lock(xfs_Gqm);
					xfs_dqlock(dqp);
					dqp->dq_flags &= ~(XFS_DQ_WANT);
				}
				flist_locked = B_TRUE;
			}

			/*
			 * id couldn't have changed; we had the hashlock all
			 * along
			 */
			ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);

			if (flist_locked) {
				if (dqp->q_nrefs != 0) {
					xfs_qm_freelist_unlock(xfs_Gqm);
					flist_locked = B_FALSE;
				} else {
					/*
					 * take it off the freelist
					 */
					xfs_dqtrace_entry(dqp,
							"DQLOOKUP: TAKEOFF FL");
					XQM_FREELIST_REMOVE(dqp);
					/* xfs_qm_freelist_print(&(xfs_Gqm->
							qm_dqfreelist),
							"after removal"); */
				}
			}

			/*
			 * grab a reference
			 */
			XFS_DQHOLD(dqp);

			if (flist_locked)
				xfs_qm_freelist_unlock(xfs_Gqm);
			/*
			 * move the dquot to the front of the hashchain
			 */
			ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));
			if (dqp->HL_PREVP != &qh->qh_next) {
				xfs_dqtrace_entry(dqp,
						  "DQLOOKUP: HASH MOVETOFRONT");
				if ((d = dqp->HL_NEXT))
					d->HL_PREVP = dqp->HL_PREVP;
				*(dqp->HL_PREVP) = d;
				d = qh->qh_next;
				d->HL_PREVP = &dqp->HL_NEXT;
				dqp->HL_NEXT = d;
				dqp->HL_PREVP = &qh->qh_next;
				qh->qh_next = dqp;
			}
			xfs_dqtrace_entry(dqp, "LOOKUP END");
			*O_dqpp = dqp;
			ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));
			return (0);
		}
	}

	*O_dqpp = NULL;
	ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));
	return (1);
}
/* ARGSUSED */
int
xfs_qm_dqpurge(
	xfs_dquot_t	*dqp,
	uint		flags)
{
	xfs_dqhash_t	*thishash;
	xfs_mount_t	*mp;

	mp = dqp->q_mount;

	ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
	ASSERT(XFS_DQ_IS_HASH_LOCKED(dqp->q_hash));

	xfs_dqlock(dqp);
	/*
	 * We really can't afford to purge a dquot that is
	 * referenced, because these are hard refs.
	 * It shouldn't happen in general because we went thru _all_ inodes in
	 * dqrele_all_inodes before calling this and didn't let the mountlock go.
	 * However it is possible that we have dquots with temporary
	 * references that are not attached to an inode. e.g. see xfs_setattr().
	 */
	if (dqp->q_nrefs != 0) {
		xfs_dqunlock(dqp);
		XFS_DQ_HASH_UNLOCK(dqp->q_hash);
		return (1);
	}

	ASSERT(XFS_DQ_IS_ON_FREELIST(dqp));

	/*
	 * If we're turning off quotas, we have to make sure that, for
	 * example, we don't delete quota disk blocks while dquots are
	 * in the process of getting written to those disk blocks.
	 * This dquot might well be on AIL, and we can't leave it there
	 * if we're turning off quotas. Basically, we need this flush
	 * lock, and are willing to block on it.
	 */
	if (! xfs_qm_dqflock_nowait(dqp)) {
		/*
		 * Block on the flush lock after nudging dquot buffer,
		 * if it is incore.
		 */
		xfs_qm_dqflock_pushbuf_wait(dqp);
	}

	/*
	 * XXXIf we're turning this type of quotas off, we don't care
	 * about the dirty metadata sitting in this dquot. OTOH, if
	 * we're unmounting, we do care, so we flush it and wait.
	 */
	if (XFS_DQ_IS_DIRTY(dqp)) {
		xfs_dqtrace_entry(dqp, "DQPURGE ->DQFLUSH: DQDIRTY");
		/* dqflush unlocks dqflock */
		/*
		 * Given that dqpurge is a very rare occurrence, it is OK
		 * that we're holding the hashlist and mplist locks
		 * across the disk write. But, ... XXXsup
		 *
		 * We don't care about getting disk errors here. We need
		 * to purge this dquot anyway, so we go ahead regardless.
		 */
		(void) xfs_qm_dqflush(dqp, XFS_QMOPT_SYNC);
		xfs_dqflock(dqp);
	}
	ASSERT(dqp->q_pincount == 0);
	ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
	       !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));

	thishash = dqp->q_hash;
	XQM_HASHLIST_REMOVE(thishash, dqp);
	XQM_MPLIST_REMOVE(&(XFS_QI_MPL_LIST(mp)), dqp);
	/*
	 * XXX Move this to the front of the freelist, if we can get the
	 * freelist lock.
	 */
	ASSERT(XFS_DQ_IS_ON_FREELIST(dqp));

	dqp->q_mount = NULL;
	dqp->q_hash = NULL;
	dqp->dq_flags = XFS_DQ_INACTIVE;
	memset(&dqp->q_core, 0, sizeof(dqp->q_core));
	xfs_dqfunlock(dqp);
	xfs_dqunlock(dqp);
	XFS_DQ_HASH_UNLOCK(thishash);
	return (0);
}