Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e69cd00c authored by Jinshan Xiong's avatar Jinshan Xiong Committed by Greg Kroah-Hartman
Browse files

staging/lustre/lov: to not hold sub locks at initialization 



Otherwise, it will cause deadlock because it essentially holds
some sub locks and then to request others in an arbitrary order.

Signed-off-by: default avatarJinshan Xiong <jinshan.xiong@intel.com>
Reviewed-on: http://review.whamcloud.com/9152


Reviewed-by: default avatarLai Siyao <lai.siyao@intel.com>
Reviewed-by: default avatarBobi Jam <bobijam@gmail.com>
Signed-off-by: default avatarOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 178ba1e0

drivers/staging/lustre/lustre/lov/lov_lock.c

+1 −35
Original line number Diff line number Diff line
@@ -346,41 +346,7 @@ static int lov_lock_sub_init(const struct lu_env *env, 
		}

	}

	LASSERT(nr == lck->lls_nr);

	/*

	 * Then, create sub-locks. Once at least one sub-lock was created,

	 * top-lock can be reached by other threads.

	 */

	for (i = 0; i < lck->lls_nr; ++i) {

		struct cl_lock       *sublock;

		struct lov_lock_link *link;



		if (lck->lls_sub[i].sub_lock == NULL) {

			sublock = lov_sublock_alloc(env, io, lck, i, &link);

			if (IS_ERR(sublock)) {

				result = PTR_ERR(sublock);

				break;

			}

			cl_lock_get_trust(sublock);

			cl_lock_mutex_get(env, sublock);

			cl_lock_mutex_get(env, parent);

			/*

			 * recheck under mutex that sub-lock wasn't created

			 * concurrently, and that top-lock is still alive.

			 */

			if (lck->lls_sub[i].sub_lock == NULL &&

			    parent->cll_state < CLS_FREEING) {

				lov_sublock_adopt(env, lck, sublock, i, link);

				cl_lock_mutex_put(env, parent);

			} else {

				OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem);

				cl_lock_mutex_put(env, parent);

				cl_lock_unhold(env, sublock,

					       "lov-parent", parent);

			}

			cl_lock_mutex_put(env, sublock);

			cl_lock_put(env, sublock);

		}

	}

	/*

	 * Some sub-locks can be missing at this point. This is not a problem,

	 * because enqueue will create them anyway. Main duty of this function
@@ -533,7 +499,7 @@ static int lov_lock_enqueue_one(const struct lu_env *env, struct lov_lock *lck, 
static int lov_sublock_fill(const struct lu_env *env, struct cl_lock *parent,

			    struct cl_io *io, struct lov_lock *lck, int idx)

{

	struct lov_lock_link *link;

	struct lov_lock_link *link = NULL;

	struct cl_lock       *sublock;

	int		   result;