}
+
/*
- * Traverse the freelist of dquots and attempt to reclaim a maximum of
- * 'howmany' dquots. This operation races with dqlookup(), and attempts to
- * favor the lookup function ...
- * XXXsup merge this with qm_reclaim_one().
+ * Just pop the least recently used dquot off the freelist and
+ * recycle it. The returned dquot is locked.
*/
-STATIC int
-xfs_qm_shake_freelist(
- int howmany)
+STATIC xfs_dquot_t *
+xfs_qm_dqreclaim_one(void)
{
- int nreclaimed;
- xfs_dqhash_t *hash;
- xfs_dquot_t *dqp, *nextdqp;
+ xfs_dquot_t *dqpout;
+ xfs_dquot_t *dqp;
int restarts;
- int nflushes;
- if (howmany <= 0)
- return 0;
-
- nreclaimed = 0;
restarts = 0;
- nflushes = 0;
+ dqpout = NULL;
-#ifdef QUOTADEBUG
- cmn_err(CE_DEBUG, "Shake free 0x%x", howmany);
-#endif
- /* lock order is : hashchainlock, freelistlock, mplistlock */
- tryagain:
+ /* lockorder: hashchainlock, freelistlock, mplistlock, dqlock, dqflock */
+startagain:
xfs_qm_freelist_lock(xfs_Gqm);
- for (dqp = xfs_Gqm->qm_dqfreelist.qh_next;
- ((dqp != (xfs_dquot_t *) &xfs_Gqm->qm_dqfreelist) &&
- nreclaimed < howmany); ) {
+ FOREACH_DQUOT_IN_FREELIST(dqp, &(xfs_Gqm->qm_dqfreelist)) {
struct xfs_mount *mp = dqp->q_mount;
xfs_dqlock(dqp);
/*
* We are racing with dqlookup here. Naturally we don't
- * want to reclaim a dquot that lookup wants.
+ * want to reclaim a dquot that lookup wants. We release the
+ * freelist lock and start over, so that lookup will grab
+ * both the dquot and the freelistlock.
*/
if (dqp->dq_flags & XFS_DQ_WANT) {
+ ASSERT(! (dqp->dq_flags & XFS_DQ_INACTIVE));
+
+ trace_xfs_dqreclaim_want(dqp);
+
xfs_dqunlock(dqp);
xfs_qm_freelist_unlock(xfs_Gqm);
if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
- return nreclaimed;
+ return NULL;
XQM_STATS_INC(xqmstats.xs_qm_dqwants);
- goto tryagain;
+ goto startagain;
}
/*
ASSERT(! XFS_DQ_IS_DIRTY(dqp));
ASSERT(dqp->HL_PREVP == NULL);
ASSERT(list_empty(&dqp->q_mplist));
+ XQM_FREELIST_REMOVE(dqp);
+ xfs_dqunlock(dqp);
+ dqpout = dqp;
XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
- nextdqp = dqp->dq_flnext;
- goto off_freelist;
+ break;
}
+ ASSERT(dqp->q_hash);
ASSERT(!list_empty(&dqp->q_mplist));
+
/*
* Try to grab the flush lock. If this dquot is in the process of
* getting flushed to disk, we don't want to reclaim it.
*/
if (!xfs_dqflock_nowait(dqp)) {
xfs_dqunlock(dqp);
- dqp = dqp->dq_flnext;
continue;
}
if (XFS_DQ_IS_DIRTY(dqp)) {
int error;
- trace_xfs_dqshake_dirty(dqp);
+ trace_xfs_dqreclaim_dirty(dqp);
/*
* We flush it delayed write, so don't bother
- * releasing the mplock.
+ * releasing the freelist lock.
*/
error = xfs_qm_dqflush(dqp, 0);
if (error) {
xfs_fs_cmn_err(CE_WARN, mp,
- "xfs_qm_dqflush_all: dquot %p flush failed", dqp);
+ "xfs_qm_dqreclaim: dquot %p flush failed", dqp);
}
xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
- dqp = dqp->dq_flnext;
continue;
}
+
/*
* We're trying to get the hashlock out of order. This races
* with dqlookup; so, we giveup and goto the next dquot if
* waiting for the freelist lock.
*/
if (!mutex_trylock(&dqp->q_hash->qh_lock)) {
- xfs_dqfunlock(dqp);
- xfs_dqunlock(dqp);
- dqp = dqp->dq_flnext;
- continue;
+ restarts++;
+ goto dqfunlock;
}
+
/*
* This races with dquot allocation code as well as dqflush_all
* and reclaim code. So, if we failed to grab the mplist lock,
* giveup everything and start over.
*/
- hash = dqp->q_hash;
- ASSERT(hash);
if (!mutex_trylock(&mp->m_quotainfo->qi_dqlist_lock)) {
- /* XXX put a sentinel so that we can come back here */
+ restarts++;
+ mutex_unlock(&dqp->q_hash->qh_lock);
xfs_dqfunlock(dqp);
xfs_dqunlock(dqp);
- mutex_unlock(&hash->qh_lock);
xfs_qm_freelist_unlock(xfs_Gqm);
- if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
- return nreclaimed;
- goto tryagain;
+ if (restarts++ >= XFS_QM_RECLAIM_MAX_RESTARTS)
+ return NULL;
+ goto startagain;
}
- trace_xfs_dqshake_unlink(dqp);
-
-#ifdef QUOTADEBUG
- cmn_err(CE_DEBUG, "Shake 0x%p, ID 0x%x\n",
- dqp, be32_to_cpu(dqp->q_core.d_id));
-#endif
ASSERT(dqp->q_nrefs == 0);
- nextdqp = dqp->dq_flnext;
- XQM_HASHLIST_REMOVE(hash, dqp);
list_del_init(&dqp->q_mplist);
mp->m_quotainfo->qi_dquots--;
mp->m_quotainfo->qi_dqreclaims++;
- xfs_dqfunlock(dqp);
- mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
- mutex_unlock(&hash->qh_lock);
-
- off_freelist:
+ XQM_HASHLIST_REMOVE(dqp->q_hash, dqp);
XQM_FREELIST_REMOVE(dqp);
+ dqpout = dqp;
+ mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
+ mutex_unlock(&dqp->q_hash->qh_lock);
+dqfunlock:
+ xfs_dqfunlock(dqp);
xfs_dqunlock(dqp);
- nreclaimed++;
- XQM_STATS_INC(xqmstats.xs_qm_dqshake_reclaims);
- xfs_qm_dqdestroy(dqp);
- dqp = nextdqp;
+ if (dqpout)
+ break;
+ if (restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
+ return NULL;
}
xfs_qm_freelist_unlock(xfs_Gqm);
- return nreclaimed;
+ return dqpout;
}
+/*
+ * Traverse the freelist of dquots and attempt to reclaim a maximum of
+ * 'howmany' dquots. This operation races with dqlookup(), and attempts to
+ * favor the lookup function ...
+ */
+STATIC int
+xfs_qm_shake_freelist(
+ int howmany)
+{
+ int nreclaimed = 0;
+ xfs_dquot_t *dqp;
+
+ if (howmany <= 0)
+ return 0;
+
+ while (nreclaimed < howmany) {
+ dqp = xfs_qm_dqreclaim_one();
+ if (!dqp)
+ return nreclaimed;
+ xfs_qm_dqdestroy(dqp);
+ nreclaimed++;
+ }
+ return nreclaimed;
+}
/*
* The kmem_shake interface is invoked when memory is running low.
}
-/*
- * Just pop the least recently used dquot off the freelist and
- * recycle it. The returned dquot is locked.
- */
-STATIC xfs_dquot_t *
-xfs_qm_dqreclaim_one(void)
-{
- xfs_dquot_t *dqpout;
- xfs_dquot_t *dqp;
- int restarts;
- int nflushes;
-
- restarts = 0;
- dqpout = NULL;
- nflushes = 0;
-
- /* lockorder: hashchainlock, freelistlock, mplistlock, dqlock, dqflock */
- startagain:
- xfs_qm_freelist_lock(xfs_Gqm);
-
- FOREACH_DQUOT_IN_FREELIST(dqp, &(xfs_Gqm->qm_dqfreelist)) {
- struct xfs_mount *mp = dqp->q_mount;
- xfs_dqlock(dqp);
-
- /*
- * We are racing with dqlookup here. Naturally we don't
- * want to reclaim a dquot that lookup wants. We release the
- * freelist lock and start over, so that lookup will grab
- * both the dquot and the freelistlock.
- */
- if (dqp->dq_flags & XFS_DQ_WANT) {
- ASSERT(! (dqp->dq_flags & XFS_DQ_INACTIVE));
-
- trace_xfs_dqreclaim_want(dqp);
-
- xfs_dqunlock(dqp);
- xfs_qm_freelist_unlock(xfs_Gqm);
- if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
- return NULL;
- XQM_STATS_INC(xqmstats.xs_qm_dqwants);
- goto startagain;
- }
-
- /*
- * If the dquot is inactive, we are assured that it is
- * not on the mplist or the hashlist, and that makes our
- * life easier.
- */
- if (dqp->dq_flags & XFS_DQ_INACTIVE) {
- ASSERT(mp == NULL);
- ASSERT(! XFS_DQ_IS_DIRTY(dqp));
- ASSERT(dqp->HL_PREVP == NULL);
- ASSERT(list_empty(&dqp->q_mplist));
- XQM_FREELIST_REMOVE(dqp);
- xfs_dqunlock(dqp);
- dqpout = dqp;
- XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
- break;
- }
-
- ASSERT(dqp->q_hash);
- ASSERT(!list_empty(&dqp->q_mplist));
-
- /*
- * Try to grab the flush lock. If this dquot is in the process of
- * getting flushed to disk, we don't want to reclaim it.
- */
- if (!xfs_dqflock_nowait(dqp)) {
- xfs_dqunlock(dqp);
- continue;
- }
-
- /*
- * We have the flush lock so we know that this is not in the
- * process of being flushed. So, if this is dirty, flush it
- * DELWRI so that we don't get a freelist infested with
- * dirty dquots.
- */
- if (XFS_DQ_IS_DIRTY(dqp)) {
- int error;
-
- trace_xfs_dqreclaim_dirty(dqp);
-
- /*
- * We flush it delayed write, so don't bother
- * releasing the freelist lock.
- */
- error = xfs_qm_dqflush(dqp, 0);
- if (error) {
- xfs_fs_cmn_err(CE_WARN, mp,
- "xfs_qm_dqreclaim: dquot %p flush failed", dqp);
- }
- xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
- continue;
- }
-
- if (!mutex_trylock(&mp->m_quotainfo->qi_dqlist_lock)) {
- xfs_dqfunlock(dqp);
- xfs_dqunlock(dqp);
- continue;
- }
-
- if (!mutex_trylock(&dqp->q_hash->qh_lock))
- goto mplistunlock;
-
- trace_xfs_dqreclaim_unlink(dqp);
-
- ASSERT(dqp->q_nrefs == 0);
- list_del_init(&dqp->q_mplist);
- mp->m_quotainfo->qi_dquots--;
- mp->m_quotainfo->qi_dqreclaims++;
- XQM_HASHLIST_REMOVE(dqp->q_hash, dqp);
- XQM_FREELIST_REMOVE(dqp);
- dqpout = dqp;
- mutex_unlock(&dqp->q_hash->qh_lock);
- mplistunlock:
- mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
- xfs_dqfunlock(dqp);
- xfs_dqunlock(dqp);
- if (dqpout)
- break;
- }
-
- xfs_qm_freelist_unlock(xfs_Gqm);
- return dqpout;
-}
-
-
/*------------------------------------------------------------------*/
/*
git.openpandora.org / pandora-kernel.git / commitdiff