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Commit a8610297 authored by Fan Yong's avatar Fan Yong Committed by Greg Kroah-Hartman
Browse files

staging: lustre: obdclass: bug fixes for lu_device_type handling 



There was no protection when inc/dec lu_device_type::ldt_device_nr,
which may caused the ldt_device_nr to be wrong and trigger assert.
This patch redefine lu_device_type::ldt_device_nr as atomic type.

There was no protection when add/del lu_device_type::ldt_linkage
into/from the global lu_device_types list, which may caused bad
address accessing. This patch uses the existing obd_types_lock
to protect related operations.

We do NOT need lu_types_stop() any longer. Such function scans
the global lu_device_types list, and for each type item on it
which has zerod lu_device_type::ldt_device_nr, call its stop()
method. In fact, the lu_device_type::ldt_device_nr only will be
zero when the last lu_device_fini() is called, and at that time,
inside the lu_device_fini(), its stop() method will be called.
So it is unnecessary to call the stop() again via lu_types_stop().

Signed-off-by: default avatarFan Yong <fan.yong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4604
Reviewed-on: http://review.whamcloud.com/8694


Reviewed-by: default avatarJian Yu <jian.yu@intel.com>
Reviewed-by: default avatarAndreas Dilger <andreas.dilger@intel.com>
Reviewed-by: default avatarOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: default avatarJames Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f4ba0420

drivers/staging/lustre/lustre/include/lu_object.h

+1 −2
Original line number Diff line number Diff line
@@ -327,7 +327,7 @@ struct lu_device_type { 
	/**

	 * Number of existing device type instances.

	 */

	unsigned				ldt_device_nr;

	atomic_t				ldt_device_nr;

	/**

	 * Linkage into a global list of all device types.

	 *
@@ -673,7 +673,6 @@ void lu_object_add(struct lu_object *before, struct lu_object *o); 


int  lu_device_type_init(struct lu_device_type *ldt);

void lu_device_type_fini(struct lu_device_type *ldt);

void lu_types_stop(void);



/** @} ctors */

drivers/staging/lustre/lustre/llite/vvp_dev.c

+0 −6
Original line number Diff line number Diff line
@@ -368,12 +368,6 @@ int cl_sb_fini(struct super_block *sb) 
		CERROR("Cannot cleanup cl-stack due to memory shortage.\n");

		result = PTR_ERR(env);

	}

	/*

	 * If mount failed (sbi->ll_cl == NULL), and this there are no other

	 * mounts, stop device types manually (this usually happens

	 * automatically when last device is destroyed).

	 */

	lu_types_stop();

	return result;

}

drivers/staging/lustre/lustre/obdclass/lu_object.c

+17 −17
Original line number Diff line number Diff line
@@ -726,34 +726,31 @@ int lu_device_type_init(struct lu_device_type *ldt) 
{

	int result = 0;



	atomic_set(&ldt->ldt_device_nr, 0);

	INIT_LIST_HEAD(&ldt->ldt_linkage);

	if (ldt->ldt_ops->ldto_init)

		result = ldt->ldt_ops->ldto_init(ldt);

	if (result == 0)



	if (!result) {

		spin_lock(&obd_types_lock);

		list_add(&ldt->ldt_linkage, &lu_device_types);

		spin_unlock(&obd_types_lock);

	}



	return result;

}

EXPORT_SYMBOL(lu_device_type_init);



void lu_device_type_fini(struct lu_device_type *ldt)

{

	spin_lock(&obd_types_lock);

	list_del_init(&ldt->ldt_linkage);

	spin_unlock(&obd_types_lock);

	if (ldt->ldt_ops->ldto_fini)

		ldt->ldt_ops->ldto_fini(ldt);

}

EXPORT_SYMBOL(lu_device_type_fini);



void lu_types_stop(void)

{

	struct lu_device_type *ldt;



	list_for_each_entry(ldt, &lu_device_types, ldt_linkage) {

		if (ldt->ldt_device_nr == 0 && ldt->ldt_ops->ldto_stop)

			ldt->ldt_ops->ldto_stop(ldt);

	}

}

EXPORT_SYMBOL(lu_types_stop);



/**

 * Global list of all sites on this node

 */
@@ -1082,8 +1079,10 @@ EXPORT_SYMBOL(lu_device_put); 
 */

int lu_device_init(struct lu_device *d, struct lu_device_type *t)

{

	if (t->ldt_device_nr++ == 0 && t->ldt_ops->ldto_start)

	if (atomic_inc_return(&t->ldt_device_nr) == 1 &&

	    t->ldt_ops->ldto_start)

		t->ldt_ops->ldto_start(t);



	memset(d, 0, sizeof(*d));

	atomic_set(&d->ld_ref, 0);

	d->ld_type = t;
@@ -1098,9 +1097,8 @@ EXPORT_SYMBOL(lu_device_init); 
 */

void lu_device_fini(struct lu_device *d)

{

	struct lu_device_type *t;

	struct lu_device_type *t = d->ld_type;



	t = d->ld_type;

	if (d->ld_obd) {

		d->ld_obd->obd_lu_dev = NULL;

		d->ld_obd = NULL;
@@ -1109,8 +1107,10 @@ void lu_device_fini(struct lu_device *d) 
	lu_ref_fini(&d->ld_reference);

	LASSERTF(atomic_read(&d->ld_ref) == 0,

		 "Refcount is %u\n", atomic_read(&d->ld_ref));

	LASSERT(t->ldt_device_nr > 0);

	if (--t->ldt_device_nr == 0 && t->ldt_ops->ldto_stop)

	LASSERT(atomic_read(&t->ldt_device_nr) > 0);



	if (atomic_dec_and_test(&t->ldt_device_nr) &&

	    t->ldt_ops->ldto_stop)

		t->ldt_ops->ldto_stop(t);

}

EXPORT_SYMBOL(lu_device_fini);

drivers/staging/lustre/lustre/obdclass/obd_mount.c

+0 −1
Original line number Diff line number Diff line
@@ -670,7 +670,6 @@ int lustre_common_put_super(struct super_block *sb) 
	}

	/* Drop a ref to the mounted disk */

	lustre_put_lsi(sb);

	lu_types_stop();

	return rc;

}

EXPORT_SYMBOL(lustre_common_put_super);