Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6:
  ocfs2: Remove ocfs2_dquot_initialize() and ocfs2_dquot_drop()
  quota: Improve locking

fs/dquot.c

@@ -87,14 +87,17 @@
 #define __DQUOT_PARANOIA
 
 /*
- * There are two quota SMP locks. dq_list_lock protects all lists with quotas
- * and quota formats and also dqstats structure containing statistics about the
- * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures
- * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
+ * There are three quota SMP locks. dq_list_lock protects all lists with quotas
+ * and quota formats, dqstats structure containing statistics about the lists
+ * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
+ * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
  * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
- * in inode_add_bytes() and inode_sub_bytes().
+ * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
+ * modifications of quota state (on quotaon and quotaoff) and readers who care
+ * about latest values take it as well.
  *
- * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock
+ * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
+ *   dq_list_lock > dq_state_lock
  *
  * Note that some things (eg. sb pointer, type, id) doesn't change during
  * the life of the dquot structure and so needn't to be protected by a lock
@@ -103,12 +106,7 @@
  * operation is just reading pointers from inode (or not using them at all) the
  * read lock is enough. If pointers are altered function must hold write lock
  * (these locking rules also apply for S_NOQUOTA flag in the inode - note that
- * for altering the flag i_mutex is also needed).  If operation is holding
- * reference to dquot in other way (e.g. quotactl ops) it must be guarded by
- * dqonoff_mutex.
- * This locking assures that:
- *   a) update/access to dquot pointers in inode is serialized
- *   b) everyone is guarded against invalidate_dquots()
+ * for altering the flag i_mutex is also needed).
  *
  * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
  * from inodes (dquot_alloc_space() and such don't check the dq_lock).
@@ -122,10 +120,17 @@
  * Lock ordering (including related VFS locks) is the following:
  *   i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock >
  *   dqio_mutex
+ * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem >
+ * dqptr_sem. But filesystem has to count with the fact that functions such as
+ * dquot_alloc_space() acquire dqptr_sem and they usually have to be called
+ * from inside a transaction to keep filesystem consistency after a crash. Also
+ * filesystems usually want to do some IO on dquot from ->mark_dirty which is
+ * called with dqptr_sem held.
  * i_mutex on quota files is special (it's below dqio_mutex)
  */
 
 static DEFINE_SPINLOCK(dq_list_lock);
+static DEFINE_SPINLOCK(dq_state_lock);
 DEFINE_SPINLOCK(dq_data_lock);
 
 static char *quotatypes[] = INITQFNAMES;
@@ -428,7 +433,7 @@ static inline void do_destroy_dquot(struct dquot *dquot)
  * quota is disabled and pointers from inodes removed so there cannot be new
  * quota users. There can still be some users of quotas due to inodes being
  * just deleted or pruned by prune_icache() (those are not attached to any
- * list). We have to wait for such users.
+ * list) or parallel quotactl call. We have to wait for such users.
  */
 static void invalidate_dquots(struct super_block *sb, int type)
 {
@@ -600,7 +605,6 @@ static struct shrinker dqcache_shrinker = {
 /*
  * Put reference to dquot
  * NOTE: If you change this function please check whether dqput_blocks() works right...
- * MUST be called with either dqptr_sem or dqonoff_mutex held
  */
 void dqput(struct dquot *dquot)
 {
@@ -696,37 +700,31 @@ static struct dquot *get_empty_dquot(struct super_block *sb, int type)
 	return dquot;
 }
 
-/*
- * Check whether dquot is in memory.
- * MUST be called with either dqptr_sem or dqonoff_mutex held
- */
-int dquot_is_cached(struct super_block *sb, unsigned int id, int type)
-{
-	unsigned int hashent = hashfn(sb, id, type);
-	int ret = 0;
-
-        if (!sb_has_quota_active(sb, type))
-		return 0;
-	spin_lock(&dq_list_lock);
-	if (find_dquot(hashent, sb, id, type) != NODQUOT)
-		ret = 1;
-	spin_unlock(&dq_list_lock);
-	return ret;
-}
-
 /*
  * Get reference to dquot
- * MUST be called with either dqptr_sem or dqonoff_mutex held
+ *
+ * Locking is slightly tricky here. We are guarded from parallel quotaoff()
+ * destroying our dquot by:
+ *   a) checking for quota flags under dq_list_lock and
+ *   b) getting a reference to dquot before we release dq_list_lock
  */
 struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
 {
 	unsigned int hashent = hashfn(sb, id, type);
-	struct dquot *dquot, *empty = NODQUOT;
+	struct dquot *dquot = NODQUOT, *empty = NODQUOT;
 
         if (!sb_has_quota_active(sb, type))
 		return NODQUOT;
 we_slept:
 	spin_lock(&dq_list_lock);
+	spin_lock(&dq_state_lock);
+	if (!sb_has_quota_active(sb, type)) {
+		spin_unlock(&dq_state_lock);
+		spin_unlock(&dq_list_lock);
+		goto out;
+	}
+	spin_unlock(&dq_state_lock);
+
 	if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) {
 		if (empty == NODQUOT) {
 			spin_unlock(&dq_list_lock);
@@ -735,6 +733,7 @@ struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
 			goto we_slept;
 		}
 		dquot = empty;
+		empty = NODQUOT;
 		dquot->dq_id = id;
 		/* all dquots go on the inuse_list */
 		put_inuse(dquot);
@@ -749,8 +748,6 @@ struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
 		dqstats.cache_hits++;
 		dqstats.lookups++;
 		spin_unlock(&dq_list_lock);
-		if (empty)
-			do_destroy_dquot(empty);
 	}
 	/* Wait for dq_lock - after this we know that either dquot_release() is already
 	 * finished or it will be canceled due to dq_count > 1 test */
@@ -758,11 +755,15 @@ struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
 	/* Read the dquot and instantiate it (everything done only if needed) */
 	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
 		dqput(dquot);
-		return NODQUOT;
+		dquot = NODQUOT;
+		goto out;
 	}
 #ifdef __DQUOT_PARANOIA
 	BUG_ON(!dquot->dq_sb);	/* Has somebody invalidated entry under us? */
 #endif
+out:
+	if (empty)
+		do_destroy_dquot(empty);
 
 	return dquot;
 }
@@ -1198,25 +1199,25 @@ static int info_bdq_free(struct dquot *dquot, qsize_t space)
 }
 /*
  *	Initialize quota pointers in inode
- *	Transaction must be started at entry
+ *	We do things in a bit complicated way but by that we avoid calling
+ *	dqget() and thus filesystem callbacks under dqptr_sem.
  */
 int dquot_initialize(struct inode *inode, int type)
 {
 	unsigned int id = 0;
 	int cnt, ret = 0;
+	struct dquot *got[MAXQUOTAS] = { NODQUOT, NODQUOT };
+	struct super_block *sb = inode->i_sb;
 
 	/* First test before acquiring mutex - solves deadlocks when we
          * re-enter the quota code and are already holding the mutex */
 	if (IS_NOQUOTA(inode))
 		return 0;
-	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
-	/* Having dqptr_sem we know NOQUOTA flags can't be altered... */
-	if (IS_NOQUOTA(inode))
-		goto out_err;
+
+	/* First get references to structures we might need. */
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
 		if (type != -1 && cnt != type)
 			continue;
-		if (inode->i_dquot[cnt] == NODQUOT) {
 		switch (cnt) {
 		case USRQUOTA:
 			id = inode->i_uid;
@@ -1225,36 +1226,49 @@ int dquot_initialize(struct inode *inode, int type)
 			id = inode->i_gid;
 			break;
 		}
-			inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt);
+		got[cnt] = dqget(sb, id, cnt);
+	}
+
+	down_write(&sb_dqopt(sb)->dqptr_sem);
+	/* Having dqptr_sem we know NOQUOTA flags can't be altered... */
+	if (IS_NOQUOTA(inode))
+		goto out_err;
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (type != -1 && cnt != type)
+			continue;
+		/* Avoid races with quotaoff() */
+		if (!sb_has_quota_active(sb, cnt))
+			continue;
+		if (inode->i_dquot[cnt] == NODQUOT) {
+			inode->i_dquot[cnt] = got[cnt];
+			got[cnt] = NODQUOT;
 		}
 	}
 out_err:
-	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	up_write(&sb_dqopt(sb)->dqptr_sem);
+	/* Drop unused references */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		dqput(got[cnt]);
 	return ret;
 }
 
 /*
  * 	Release all quotas referenced by inode
- *	Transaction must be started at an entry
  */
-int dquot_drop_locked(struct inode *inode)
+int dquot_drop(struct inode *inode)
 {
 	int cnt;
+	struct dquot *put[MAXQUOTAS];
 
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (inode->i_dquot[cnt] != NODQUOT) {
-			dqput(inode->i_dquot[cnt]);
+		put[cnt] = inode->i_dquot[cnt];
 		inode->i_dquot[cnt] = NODQUOT;
 	}
-	}
-	return 0;
-}
-
-int dquot_drop(struct inode *inode)
-{
-	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
-	dquot_drop_locked(inode);
 	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		dqput(put[cnt]);
 	return 0;
 }
 
@@ -1470,8 +1484,9 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
 	qsize_t space;
 	struct dquot *transfer_from[MAXQUOTAS];
 	struct dquot *transfer_to[MAXQUOTAS];
-	int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid,
-	    chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid;
+	int cnt, ret = QUOTA_OK;
+	int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid,
+	    chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid;
 	char warntype_to[MAXQUOTAS];
 	char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS];
 
@@ -1479,21 +1494,11 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
          * re-enter the quota code and are already holding the mutex */
 	if (IS_NOQUOTA(inode))
 		return QUOTA_OK;
-	/* Clear the arrays */
+	/* Initialize the arrays */
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		transfer_to[cnt] = transfer_from[cnt] = NODQUOT;
+		transfer_from[cnt] = NODQUOT;
+		transfer_to[cnt] = NODQUOT;
 		warntype_to[cnt] = QUOTA_NL_NOWARN;
-	}
-	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
-	/* Now recheck reliably when holding dqptr_sem */
-	if (IS_NOQUOTA(inode)) {	/* File without quota accounting? */
-		up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
-		return QUOTA_OK;
-	}
-	/* First build the transfer_to list - here we can block on
-	 * reading/instantiating of dquots.  We know that the transaction for
-	 * us was already started so we don't violate lock ranking here */
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
 		switch (cnt) {
 			case USRQUOTA:
 				if (!chuid)
@@ -1507,6 +1512,13 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
 				break;
 		}
 	}
+
+	down_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	/* Now recheck reliably when holding dqptr_sem */
+	if (IS_NOQUOTA(inode)) {	/* File without quota accounting? */
+		up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+		goto put_all;
+	}
 	spin_lock(&dq_data_lock);
 	space = inode_get_bytes(inode);
 	/* Build the transfer_from list and check the limits */
@@ -1517,7 +1529,7 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
 		if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) ==
 		    NO_QUOTA || check_bdq(transfer_to[cnt], space, 0,
 		    warntype_to + cnt) == NO_QUOTA)
-			goto warn_put_all;
+			goto over_quota;
 	}
 
 	/*
@@ -1545,28 +1557,37 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
 
 		inode->i_dquot[cnt] = transfer_to[cnt];
 	}
-	ret = QUOTA_OK;
-warn_put_all:
 	spin_unlock(&dq_data_lock);
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+
 	/* Dirtify all the dquots - this can block when journalling */
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
 		if (transfer_from[cnt])
 			mark_dquot_dirty(transfer_from[cnt]);
-		if (transfer_to[cnt])
+		if (transfer_to[cnt]) {
 			mark_dquot_dirty(transfer_to[cnt]);
+			/* The reference we got is transferred to the inode */
+			transfer_to[cnt] = NODQUOT;
+		}
 	}
+warn_put_all:
 	flush_warnings(transfer_to, warntype_to);
 	flush_warnings(transfer_from, warntype_from_inodes);
 	flush_warnings(transfer_from, warntype_from_space);
-	
+put_all:
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT)
 		dqput(transfer_from[cnt]);
-		if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT)
 		dqput(transfer_to[cnt]);
 	}
-	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
 	return ret;
+over_quota:
+	spin_unlock(&dq_data_lock);
+	up_write(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	/* Clear dquot pointers we don't want to dqput() */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
+		transfer_from[cnt] = NODQUOT;
+	ret = NO_QUOTA;
+	goto warn_put_all;
 }
 
 /* Wrapper for transferring ownership of an inode */
@@ -1651,19 +1672,24 @@ int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags)
 			continue;
 
 		if (flags & DQUOT_SUSPENDED) {
+			spin_lock(&dq_state_lock);
 			dqopt->flags |=
 				dquot_state_flag(DQUOT_SUSPENDED, cnt);
+			spin_unlock(&dq_state_lock);
 		} else {
+			spin_lock(&dq_state_lock);
 			dqopt->flags &= ~dquot_state_flag(flags, cnt);
 			/* Turning off suspended quotas? */
 			if (!sb_has_quota_loaded(sb, cnt) &&
 			    sb_has_quota_suspended(sb, cnt)) {
 				dqopt->flags &=	~dquot_state_flag(
 							DQUOT_SUSPENDED, cnt);
+				spin_unlock(&dq_state_lock);
 				iput(dqopt->files[cnt]);
 				dqopt->files[cnt] = NULL;
 				continue;
 			}
+			spin_unlock(&dq_state_lock);
 		}
 
 		/* We still have to keep quota loaded? */
@@ -1830,7 +1856,9 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
 	}
 	mutex_unlock(&dqopt->dqio_mutex);
 	mutex_unlock(&inode->i_mutex);
+	spin_lock(&dq_state_lock);
 	dqopt->flags |= dquot_state_flag(flags, type);
+	spin_unlock(&dq_state_lock);
 
 	add_dquot_ref(sb, type);
 	mutex_unlock(&dqopt->dqonoff_mutex);
@@ -1872,9 +1900,11 @@ static int vfs_quota_on_remount(struct super_block *sb, int type)
 	}
 	inode = dqopt->files[type];
 	dqopt->files[type] = NULL;
+	spin_lock(&dq_state_lock);
 	flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
 						DQUOT_LIMITS_ENABLED, type);
 	dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type);
+	spin_unlock(&dq_state_lock);
 	mutex_unlock(&dqopt->dqonoff_mutex);
 
 	flags = dquot_generic_flag(flags, type);
@@ -1952,7 +1982,9 @@ int vfs_quota_enable(struct inode *inode, int type, int format_id,
 			ret = -EBUSY;
 			goto out_lock;
 		}
+		spin_lock(&dq_state_lock);
 		sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
+		spin_unlock(&dq_state_lock);
 out_lock:
 		mutex_unlock(&dqopt->dqonoff_mutex);
 		return ret;
@@ -2039,14 +2071,12 @@ int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *d
 {
 	struct dquot *dquot;
 
-	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
-	if (!(dquot = dqget(sb, id, type))) {
-		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+	dquot = dqget(sb, id, type);
+	if (dquot == NODQUOT)
 		return -ESRCH;
-	}
 	do_get_dqblk(dquot, di);
 	dqput(dquot);
-	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+
 	return 0;
 }
 
@@ -2130,7 +2160,6 @@ int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *d
 	struct dquot *dquot;
 	int rc;
 
-	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
 	dquot = dqget(sb, id, type);
 	if (!dquot) {
 		rc = -ESRCH;
@@ -2139,7 +2168,6 @@ int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *d
 	rc = do_set_dqblk(dquot, di);
 	dqput(dquot);
 out:
-	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 	return rc;
 }
 
@@ -2370,11 +2398,9 @@ EXPORT_SYMBOL(dquot_release);
 EXPORT_SYMBOL(dquot_mark_dquot_dirty);
 EXPORT_SYMBOL(dquot_initialize);
 EXPORT_SYMBOL(dquot_drop);
-EXPORT_SYMBOL(dquot_drop_locked);
 EXPORT_SYMBOL(vfs_dq_drop);
 EXPORT_SYMBOL(dqget);
 EXPORT_SYMBOL(dqput);
-EXPORT_SYMBOL(dquot_is_cached);
 EXPORT_SYMBOL(dquot_alloc_space);
 EXPORT_SYMBOL(dquot_alloc_inode);
 EXPORT_SYMBOL(dquot_free_space);

fs/ocfs2/quota_global.c

@@ -810,171 +810,6 @@ static int ocfs2_write_info(struct super_block *sb, int type)
 	return status;
 }
 
-/* This is difficult. We have to lock quota inode and start transaction
- * in this function but we don't want to take the penalty of exlusive
- * quota file lock when we are just going to use cached structures. So
- * we just take read lock check whether we have dquot cached and if so,
- * we don't have to take the write lock... */
-static int ocfs2_dquot_initialize(struct inode *inode, int type)
-{
-	handle_t *handle = NULL;
-	int status = 0;
-	struct super_block *sb = inode->i_sb;
-	struct ocfs2_mem_dqinfo *oinfo;
-	int exclusive = 0;
-	int cnt;
-	qid_t id;
-
-	mlog_entry_void();
-
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (type != -1 && cnt != type)
-			continue;
-		if (!sb_has_quota_active(sb, cnt))
-			continue;
-		oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
-		status = ocfs2_lock_global_qf(oinfo, 0);
-		if (status < 0)
-			goto out;
-		/* This is just a performance optimization not a reliable test.
-		 * Since we hold an inode lock, noone can actually release
-		 * the structure until we are finished with initialization. */
-		if (inode->i_dquot[cnt] != NODQUOT) {
-			ocfs2_unlock_global_qf(oinfo, 0);
-			continue;
-		}
-		/* When we have inode lock, we know that no dquot_release() can
-		 * run and thus we can safely check whether we need to
-		 * read+modify global file to get quota information or whether
-		 * our node already has it. */
-		if (cnt == USRQUOTA)
-			id = inode->i_uid;
-		else if (cnt == GRPQUOTA)
-			id = inode->i_gid;
-		else
-			BUG();
-		/* Obtain exclusion from quota off... */
-		down_write(&sb_dqopt(sb)->dqptr_sem);
-		exclusive = !dquot_is_cached(sb, id, cnt);
-		up_write(&sb_dqopt(sb)->dqptr_sem);
-		if (exclusive) {
-			status = ocfs2_lock_global_qf(oinfo, 1);
-			if (status < 0) {
-				exclusive = 0;
-				mlog_errno(status);
-				goto out_ilock;
-			}
-			handle = ocfs2_start_trans(OCFS2_SB(sb),
-					ocfs2_calc_qinit_credits(sb, cnt));
-			if (IS_ERR(handle)) {
-				status = PTR_ERR(handle);
-				mlog_errno(status);
-				goto out_ilock;
-			}
-		}
-		dquot_initialize(inode, cnt);
-		if (exclusive) {
-			ocfs2_commit_trans(OCFS2_SB(sb), handle);
-			ocfs2_unlock_global_qf(oinfo, 1);
-		}
-		ocfs2_unlock_global_qf(oinfo, 0);
-	}
-	mlog_exit(0);
-	return 0;
-out_ilock:
-	if (exclusive)
-		ocfs2_unlock_global_qf(oinfo, 1);
-	ocfs2_unlock_global_qf(oinfo, 0);
-out:
-	mlog_exit(status);
-	return status;
-}
-
-static int ocfs2_dquot_drop_slow(struct inode *inode)
-{
-	int status = 0;
-	int cnt;
-	int got_lock[MAXQUOTAS] = {0, 0};
-	handle_t *handle;
-	struct super_block *sb = inode->i_sb;
-	struct ocfs2_mem_dqinfo *oinfo;
-
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (!sb_has_quota_active(sb, cnt))
-			continue;
-		oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
-		status = ocfs2_lock_global_qf(oinfo, 1);
-		if (status < 0)
-			goto out;
-		got_lock[cnt] = 1;
-	}
-	handle = ocfs2_start_trans(OCFS2_SB(sb),
-			ocfs2_calc_qinit_credits(sb, USRQUOTA) +
-			ocfs2_calc_qinit_credits(sb, GRPQUOTA));
-	if (IS_ERR(handle)) {
-		status = PTR_ERR(handle);
-		mlog_errno(status);
-		goto out;
-	}
-	dquot_drop(inode);
-	ocfs2_commit_trans(OCFS2_SB(sb), handle);
-out:
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
-		if (got_lock[cnt]) {
-			oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
-			ocfs2_unlock_global_qf(oinfo, 1);
-		}
-	return status;
-}
-
-/* See the comment before ocfs2_dquot_initialize. */
-static int ocfs2_dquot_drop(struct inode *inode)
-{
-	int status = 0;
-	struct super_block *sb = inode->i_sb;
-	struct ocfs2_mem_dqinfo *oinfo;
-	int exclusive = 0;
-	int cnt;
-	int got_lock[MAXQUOTAS] = {0, 0};
-
-	mlog_entry_void();
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (!sb_has_quota_active(sb, cnt))
-			continue;
-		oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
-		status = ocfs2_lock_global_qf(oinfo, 0);
-		if (status < 0)
-			goto out;
-		got_lock[cnt] = 1;
-	}
-	/* Lock against anyone releasing references so that when when we check
-	 * we know we are not going to be last ones to release dquot */
-	down_write(&sb_dqopt(sb)->dqptr_sem);
-	/* Urgh, this is a terrible hack :( */
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
-		if (inode->i_dquot[cnt] != NODQUOT &&
-		    atomic_read(&inode->i_dquot[cnt]->dq_count) > 1) {
-			exclusive = 1;
-			break;
-		}
-	}
-	if (!exclusive)
-		dquot_drop_locked(inode);
-	up_write(&sb_dqopt(sb)->dqptr_sem);
-out:
-	for (cnt = 0; cnt < MAXQUOTAS; cnt++)
-		if (got_lock[cnt]) {
-			oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
-			ocfs2_unlock_global_qf(oinfo, 0);
-		}
-	/* In case we bailed out because we had to do expensive locking
-	 * do it now... */
-	if (exclusive)
-		status = ocfs2_dquot_drop_slow(inode);
-	mlog_exit(status);
-	return status;
-}
-
 static struct dquot *ocfs2_alloc_dquot(struct super_block *sb, int type)
 {
 	struct ocfs2_dquot *dquot =
@@ -991,8 +826,8 @@ static void ocfs2_destroy_dquot(struct dquot *dquot)
 }
 
 struct dquot_operations ocfs2_quota_operations = {
-	.initialize	= ocfs2_dquot_initialize,
-	.drop		= ocfs2_dquot_drop,
+	.initialize	= dquot_initialize,
+	.drop		= dquot_drop,
 	.alloc_space	= dquot_alloc_space,
 	.alloc_inode	= dquot_alloc_inode,
 	.free_space	= dquot_free_space,

include/linux/quotaops.h

@@ -24,10 +24,8 @@ void sync_dquots(struct super_block *sb, int type);
 
 int dquot_initialize(struct inode *inode, int type);
 int dquot_drop(struct inode *inode);
-int dquot_drop_locked(struct inode *inode);
 struct dquot *dqget(struct super_block *sb, unsigned int id, int type);
 void dqput(struct dquot *dquot);
-int dquot_is_cached(struct super_block *sb, unsigned int id, int type);
 int dquot_scan_active(struct super_block *sb,
 		      int (*fn)(struct dquot *dquot, unsigned long priv),
 		      unsigned long priv);