From: Jason Gunthorpe <jgg@xxxxxxxxxx> It is not really necessary to keep a linked list of mcs associated with each context when we can just scan the xarray to find the right things. The removes another overloading of file->mut by relying on the xarray locking for mc instead. Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx> --- drivers/infiniband/core/ucma.c | 59 +++++++++++++--------------------- 1 file changed, 22 insertions(+), 37 deletions(-) diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index 7416a5a6aa69..dd12931f3038 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -96,7 +96,6 @@ struct ucma_context { u64 uid; struct list_head list; - struct list_head mc_list; /* mark that device is in process of destroying the internal HW * resources, protected by the ctx_table lock */ @@ -113,7 +112,6 @@ struct ucma_multicast { u64 uid; u8 join_state; - struct list_head list; struct sockaddr_storage addr; }; @@ -217,7 +215,6 @@ static struct ucma_context *ucma_alloc_ctx(struct ucma_file *file) INIT_WORK(&ctx->close_work, ucma_close_id); refcount_set(&ctx->ref, 1); init_completion(&ctx->comp); - INIT_LIST_HEAD(&ctx->mc_list); /* So list_del() will work if we don't do ucma_finish_ctx() */ INIT_LIST_HEAD(&ctx->list); ctx->file = file; @@ -237,26 +234,6 @@ static void ucma_finish_ctx(struct ucma_context *ctx) xa_store(&ctx_table, ctx->id, ctx, GFP_KERNEL); } -static struct ucma_multicast* ucma_alloc_multicast(struct ucma_context *ctx) -{ - struct ucma_multicast *mc; - - mc = kzalloc(sizeof(*mc), GFP_KERNEL); - if (!mc) - return NULL; - - mc->ctx = ctx; - if (xa_alloc(&multicast_table, &mc->id, NULL, xa_limit_32b, GFP_KERNEL)) - goto error; - - list_add_tail(&mc->list, &ctx->mc_list); - return mc; - -error: - kfree(mc); - return NULL; -} - static void ucma_copy_conn_event(struct rdma_ucm_conn_param *dst, struct rdma_conn_param *src) { @@ -551,21 +528,26 @@ static ssize_t ucma_create_id(struct ucma_file *file, const char __user *inbuf, static void ucma_cleanup_multicast(struct ucma_context *ctx) { - struct ucma_multicast *mc, *tmp; + struct ucma_multicast *mc; + unsigned long index; - mutex_lock(&ctx->file->mut); - list_for_each_entry_safe(mc, tmp, &ctx->mc_list, list) { - list_del(&mc->list); - xa_erase(&multicast_table, mc->id); + xa_for_each(&multicast_table, index, mc) { + if (mc->ctx != ctx) + continue; + /* + * At this point mc->ctx->ref is 0 so the mc cannot leave the + * lock on the reader and this is enough serialization + */ + xa_erase(&multicast_table, index); kfree(mc); } - mutex_unlock(&ctx->file->mut); } static void ucma_cleanup_mc_events(struct ucma_multicast *mc) { struct ucma_event *uevent, *tmp; + mutex_lock(&mc->ctx->file->mut); list_for_each_entry_safe(uevent, tmp, &mc->ctx->file->event_list, list) { if (uevent->mc != mc) continue; @@ -573,6 +555,7 @@ static void ucma_cleanup_mc_events(struct ucma_multicast *mc) list_del(&uevent->list); kfree(uevent); } + mutex_unlock(&mc->ctx->file->mut); } /* @@ -1501,15 +1484,23 @@ static ssize_t ucma_process_join(struct ucma_file *file, if (IS_ERR(ctx)) return PTR_ERR(ctx); - mutex_lock(&file->mut); - mc = ucma_alloc_multicast(ctx); + mc = kzalloc(sizeof(*mc), GFP_KERNEL); if (!mc) { ret = -ENOMEM; goto err1; } + + mc->ctx = ctx; mc->join_state = join_state; mc->uid = cmd->uid; memcpy(&mc->addr, addr, cmd->addr_size); + + if (xa_alloc(&multicast_table, &mc->id, NULL, xa_limit_32b, + GFP_KERNEL)) { + ret = -ENOMEM; + goto err1; + } + mutex_lock(&ctx->mutex); ret = rdma_join_multicast(ctx->cm_id, (struct sockaddr *)&mc->addr, join_state, mc); @@ -1526,7 +1517,6 @@ static ssize_t ucma_process_join(struct ucma_file *file, xa_store(&multicast_table, mc->id, mc, 0); - mutex_unlock(&file->mut); ucma_put_ctx(ctx); return 0; @@ -1535,10 +1525,8 @@ static ssize_t ucma_process_join(struct ucma_file *file, ucma_cleanup_mc_events(mc); err2: xa_erase(&multicast_table, mc->id); - list_del(&mc->list); kfree(mc); err1: - mutex_unlock(&file->mut); ucma_put_ctx(ctx); return ret; } @@ -1617,10 +1605,7 @@ static ssize_t ucma_leave_multicast(struct ucma_file *file, rdma_leave_multicast(mc->ctx->cm_id, (struct sockaddr *) &mc->addr); mutex_unlock(&mc->ctx->mutex); - mutex_lock(&mc->ctx->file->mut); ucma_cleanup_mc_events(mc); - list_del(&mc->list); - mutex_unlock(&mc->ctx->file->mut); ucma_put_ctx(mc->ctx); resp.events_reported = mc->events_reported; -- 2.26.2