Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164AbaATEFw (ORCPT ); Sun, 19 Jan 2014 23:05:52 -0500 Received: from mail.linux-iscsi.org ([67.23.28.174]:44987 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753031AbaATEF0 (ORCPT ); Sun, 19 Jan 2014 23:05:26 -0500 From: "Nicholas A. Bellinger" To: target-devel Cc: linux-kernel , Linus Torvalds , Ingo Molnar , Peter Zijlstra , Kent Overstreet , Jens Axboe , Nicholas Bellinger Subject: [PATCH-v2 3/3] iscsi-target: Fix connection reset hang with percpu_ida_alloc Date: Mon, 20 Jan 2014 03:44:46 +0000 Message-Id: <1390189486-13579-4-git-send-email-nab@linux-iscsi.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1390189486-13579-1-git-send-email-nab@linux-iscsi.org> References: <1390189486-13579-1-git-send-email-nab@linux-iscsi.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Bellinger This patch addresses a bug where connection reset would hang indefinately once percpu_ida_alloc() was starved for tags, due to the fact that it always assumed uninterruptible sleep mode. So now make percpu_ida_alloc() check for signal_pending_state() for making interruptible sleep optional, and convert iscsit_allocate_cmd() to set TASK_INTERRUPTIBLE for GFP_KERNEL, or TASK_RUNNING for GFP_ATOMIC. Reported-by: Linus Torvalds Cc: Kent Overstreet Cc: #3.12+ Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target_util.c | 2 +- lib/percpu_ida.c | 9 +++++++-- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 9b8e1db..5477eca 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -156,7 +156,7 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask) { struct iscsi_cmd *cmd; struct se_session *se_sess = conn->sess->se_sess; - int size, tag, state = (gfp_mask & __GFP_WAIT) ? TASK_UNINTERRUPTIBLE : + int size, tag, state = (gfp_mask & __GFP_WAIT) ? TASK_INTERRUPTIBLE : TASK_RUNNING; tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state); diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c index a48ce2e..a667110 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -138,14 +138,14 @@ static inline unsigned alloc_local_tag(struct percpu_ida_cpu *tags) * tag_pool_init()), or otherwise -ENOSPC on allocation failure. * * Safe to be called from interrupt context (assuming it isn't passed - * TASK_UNINTERRUPTIBLE, of course). + * TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, of course). * * @gfp indicates whether or not to wait until a free id is available (it's not * used for internal memory allocations); thus if passed __GFP_WAIT we may sleep * however long it takes until another thread frees an id (same semantics as a * mempool). * - * Will not fail if passed TASK_UNINTERRUPTIBLE. + * Will not fail if passed TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE. */ int percpu_ida_alloc(struct percpu_ida *pool, int state) { @@ -194,6 +194,11 @@ int percpu_ida_alloc(struct percpu_ida *pool, int state) if (tag >= 0 || state == TASK_RUNNING) break; + if (signal_pending_state(state, current)) { + tag = -ERESTARTSYS; + break; + } + schedule(); local_irq_save(flags); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/