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yaml
---
r: 195788
b: refs/heads/master
c: 368e136
h: refs/heads/master
v: v3
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Dave Chinner authored and Alex Elder committed May 19, 2010
1 parent e5ab375 commit fbaeac5
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Showing 3 changed files with 74 additions and 194 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 3a25404b3fccd41d36b2fda18d86011201608c38
refs/heads/master: 368e136174344c417bad6ff0380b7b3f574bf120
2 changes: 0 additions & 2 deletions trunk/fs/xfs/linux-2.6/xfs_trace.h
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Expand Up @@ -653,8 +653,6 @@ DEFINE_EVENT(xfs_dquot_class, name, \
TP_PROTO(struct xfs_dquot *dqp), \
TP_ARGS(dqp))
DEFINE_DQUOT_EVENT(xfs_dqadjust);
DEFINE_DQUOT_EVENT(xfs_dqshake_dirty);
DEFINE_DQUOT_EVENT(xfs_dqshake_unlink);
DEFINE_DQUOT_EVENT(xfs_dqreclaim_want);
DEFINE_DQUOT_EVENT(xfs_dqreclaim_dirty);
DEFINE_DQUOT_EVENT(xfs_dqreclaim_unlink);
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264 changes: 73 additions & 191 deletions trunk/fs/xfs/quota/xfs_qm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1926,53 +1926,46 @@ xfs_qm_init_quotainos(
}



/*
* 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;
}

/*
Expand All @@ -1985,19 +1978,22 @@ xfs_qm_shake_freelist(
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;
}

Expand All @@ -2010,21 +2006,21 @@ xfs_qm_shake_freelist(
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
Expand All @@ -2033,57 +2029,71 @@ xfs_qm_shake_freelist(
* 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.
Expand Down Expand Up @@ -2115,134 +2125,6 @@ xfs_qm_shake(int nr_to_scan, gfp_t gfp_mask)
}


/*
* 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;
}


/*------------------------------------------------------------------*/

/*
Expand Down

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