Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755201Ab1B1Xu2 (ORCPT ); Mon, 28 Feb 2011 18:50:28 -0500 Received: from a-pb-sasl-sd.pobox.com ([64.74.157.62]:55222 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754544Ab1B1XsD (ORCPT ); Mon, 28 Feb 2011 18:48:03 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:date:message-id:in-reply-to:references; q=dns; s=sasl; b= cbnW4yWEVGvVr1AFy80WU+aSmwdVtzZ9kmBljKrBUO5smThUOJfrIQ47fP4VAcn0 Z+svVjzzLhijmzi7nKXp7xNUIOHoK0Blh3PYLi1g0LmWjuIdkVpLZ84HhmwDdTG8 41UgIge/SyzKQ5eXOAjZjqDLHFPg2ZWlwHWA8aCIvcY= From: ntl@pobox.com To: linux-kernel@vger.kernel.org Cc: containers@lists.linux-foundation.org, Oren Laadan , Nathan Lynch Subject: [PATCH 02/10] Introduce mm_has_pending_aio() helper Date: Mon, 28 Feb 2011 17:40:24 -0600 Message-Id: <1298936432-29607-3-git-send-email-ntl@pobox.com> X-Mailer: git-send-email 1.7.4 In-Reply-To: <1298936432-29607-1-git-send-email-ntl@pobox.com> References: <1298936432-29607-1-git-send-email-ntl@pobox.com> X-Pobox-Relay-ID: 5A304148-4394-11E0-B7C2-AF401E47CF6F-04752483!a-pb-sasl-sd.pobox.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2751 Lines: 81 From: Nathan Lynch Support for AIO is on the to-do list, but until that is implemented, checkpoint will have to fail if a mm_struct has outstanding AIO contexts. Add a mm_has_pending_aio() helper function for this purpose. Based on original "check_for_outstanding_aio" patch by Serge Hallyn. Signed-off-by: Serge E. Hallyn [ntl: changed name and return type to clearly express semantics] [ntl: added kerneldoc] Signed-off-by: Nathan Lynch --- fs/aio.c | 27 +++++++++++++++++++++++++++ include/linux/aio.h | 2 ++ 2 files changed, 29 insertions(+), 0 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 8c8f6c5..1acbc99 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1847,3 +1847,30 @@ SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id, asmlinkage_protect(5, ret, ctx_id, min_nr, nr, events, timeout); return ret; } + +/** + * mm_has_pending_aio() - check for outstanding AIO operations + * @mm: The mm_struct to check. + * + * Returns true if there is at least one non-dead kioctx on + * @mm->ioctx_list. Note that the result of this function is + * unreliable unless the caller has ensured that new requests cannot + * be submitted against @mm (e.g. through freezing the associated + * tasks). + */ +bool mm_has_pending_aio(struct mm_struct *mm) +{ + struct kioctx *ctx; + struct hlist_node *n; + bool has_aio = false; + + rcu_read_lock(); + hlist_for_each_entry_rcu(ctx, n, &mm->ioctx_list, list) { + if (!ctx->dead) { + has_aio = true; + break; + } + } + rcu_read_unlock(); + return has_aio; +} diff --git a/include/linux/aio.h b/include/linux/aio.h index 7a8db41..39d9936 100644 --- a/include/linux/aio.h +++ b/include/linux/aio.h @@ -214,6 +214,7 @@ struct mm_struct; extern void exit_aio(struct mm_struct *mm); extern long do_io_submit(aio_context_t ctx_id, long nr, struct iocb __user *__user *iocbpp, bool compat); +extern bool mm_has_pending_aio(struct mm_struct *mm); #else static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; } static inline int aio_put_req(struct kiocb *iocb) { return 0; } @@ -224,6 +225,7 @@ static inline void exit_aio(struct mm_struct *mm) { } static inline long do_io_submit(aio_context_t ctx_id, long nr, struct iocb __user * __user *iocbpp, bool compat) { return 0; } +static inline bool mm_has_pending_aio(struct mm_struct *mm) { return false; } #endif /* CONFIG_AIO */ static inline struct kiocb *list_kiocb(struct list_head *h) -- 1.7.4 -- 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/