diff options
| -rw-r--r-- | xlators/features/locks/src/entrylk.c | 50 | ||||
| -rw-r--r-- | xlators/features/locks/src/inodelk.c | 2 |
2 files changed, 48 insertions, 4 deletions
diff --git a/xlators/features/locks/src/entrylk.c b/xlators/features/locks/src/entrylk.c index 4f5d8aca2c6..8496d9d8dce 100644 --- a/xlators/features/locks/src/entrylk.c +++ b/xlators/features/locks/src/entrylk.c @@ -715,15 +715,16 @@ pl_entrylk_client_cleanup (xlator_t *this, pl_ctx_t *ctx) pl_inode_t *pinode = NULL; struct list_head released; + struct list_head unwind; INIT_LIST_HEAD (&released); + INIT_LIST_HEAD (&unwind); pthread_mutex_lock (&ctx->lock); { list_for_each_entry_safe (l, tmp, &ctx->entrylk_lockers, client_list) { list_del_init (&l->client_list); - list_add_tail (&l->client_list, &released); pl_entrylk_log_cleanup (l); @@ -731,19 +732,62 @@ pl_entrylk_client_cleanup (xlator_t *this, pl_ctx_t *ctx) pthread_mutex_lock (&pinode->mutex); { - list_del_init (&l->domain_list); + /* If the entrylk object is part of granted list but not + * blocked list, then perform the following actions: + * i. delete the object from granted list; + * ii. grant other locks (from other clients) that may + * have been blocked on this entrylk; and + * iii. unref the object. + * + * If the entrylk object (L1) is part of both granted + * and blocked lists, then this means that a parallel + * unlock on another entrylk (L2 say) may have 'granted' + * L1 and added it to 'granted' list in + * __grant_blocked_entry_locks() (although using the + * 'blocked_locks' member). In that case, the cleanup + * codepath must try and grant other overlapping + * blocked entrylks from other clients, now that L1 is + * out of their way and then unref L1 in the end, and + * leave it to the other thread (the one executing + * unlock codepath) to unwind L1's frame, delete it from + * blocked_locks list, and perform the last unref on L1. + * + * If the entrylk object (L1) is part of blocked list + * only, the cleanup code path must: + * i. delete it from the blocked_locks list inside + * this critical section, + * ii. unwind its frame with EAGAIN, + * iii. try and grant blocked entry locks from other + * clients that were otherwise grantable, but were + * blocked to avoid leaving L1 to starve forever. + * iv. unref the object. + */ + if (!list_empty (&l->domain_list)) { + list_del_init (&l->domain_list); + list_add_tail (&l->client_list, + &released); + } else { + list_del_init (&l->blocked_locks); + list_add_tail (&l->client_list, + &unwind); + } } pthread_mutex_unlock (&pinode->mutex); } } pthread_mutex_unlock (&ctx->lock); - list_for_each_entry_safe (l, tmp, &released, client_list) { + list_for_each_entry_safe (l, tmp, &unwind, client_list) { list_del_init (&l->client_list); if (l->frame) STACK_UNWIND_STRICT (entrylk, l->frame, -1, EAGAIN, NULL); + list_add_tail (&l->client_list, &released); + } + + list_for_each_entry_safe (l, tmp, &released, client_list) { + list_del_init (&l->client_list); pinode = l->pinode; diff --git a/xlators/features/locks/src/inodelk.c b/xlators/features/locks/src/inodelk.c index d105e14f23d..c76cb7f9199 100644 --- a/xlators/features/locks/src/inodelk.c +++ b/xlators/features/locks/src/inodelk.c @@ -26,7 +26,7 @@ inline void __delete_inode_lock (pl_inode_lock_t *lock) { - list_del (&lock->list); + list_del_init (&lock->list); } static inline void |