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

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

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-on: http://review.whamcloud.com/9152
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Bobi Jam <bobijam@gmail.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jinshan Xiong 2014-04-27 13:06:46 -04:00 • committed by Greg Kroah-Hartman
parent 178ba1e0d0
commit e69cd00cb3
1 changed files with 1 additions and 35 deletions
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36
drivers/staging/lustre/lustre/lov/lov_lock.c
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@ -346,41 +346,7 @@ static int lov_lock_sub_init(const struct lu_env *env,
} }
} }
LASSERT(nr == lck->lls_nr); 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, * 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 * 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, 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 cl_io *io, struct lov_lock *lck, int idx)
{ {
struct lov_lock_link *link; struct lov_lock_link *link = NULL;
struct cl_lock *sublock; struct cl_lock *sublock;
int result; int result;