From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932301Ab3KWW3j (ORCPT ); Sat, 23 Nov 2013 17:29:39 -0500 Received: from mail-qa0-f52.google.com ([209.85.216.52]:43646 "EHLO mail-qa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756398Ab3KWWW5 (ORCPT ); Sat, 23 Nov 2013 17:22:57 -0500 From: Tejun Heo To: gregkh@linuxfoundation.org Cc: kay@vrfy.org, linux-kernel@vger.kernel.org, ebiederm@xmission.com, bhelgaas@google.com, Tejun Heo Subject: [PATCH 21/41] sysfs, kernfs: introduce kernfs_notify() Date: Sat, 23 Nov 2013 17:22:06 -0500 Message-Id: <1385245346-856-22-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.8.4.2 In-Reply-To: <1385245346-856-1-git-send-email-tj@kernel.org> References: <1385245346-856-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce kernfs interface to wake up poll(2) which takes and returns sysfs_dirents. sysfs_notify_dirent() is renamed to kernfs_notify() and sysfs_notify() is updated so that it doesn't directly grab sysfs_mutex but acquires the target sysfs_dirents using sysfs_get_dirent(). sysfs_notify_dirent() is reimplemented as a dumb inline wrapper around kernfs_notify(). This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo --- fs/sysfs/file.c | 33 ++++++++++++++++++++++----------- include/linux/kernfs.h | 3 +++ include/linux/sysfs.h | 9 +++++---- 3 files changed, 30 insertions(+), 15 deletions(-) diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 74e3478..a68cbef 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -851,7 +851,13 @@ static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) return DEFAULT_POLLMASK|POLLERR|POLLPRI; } -void sysfs_notify_dirent(struct sysfs_dirent *sd) +/** + * kernfs_notify - notify a kernfs file + * @sd: file to notify + * + * Notify @sd such that poll(2) on @sd wakes up. + */ +void kernfs_notify(struct sysfs_dirent *sd) { struct sysfs_open_dirent *od; unsigned long flags; @@ -868,22 +874,27 @@ void sysfs_notify_dirent(struct sysfs_dirent *sd) spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); } -EXPORT_SYMBOL_GPL(sysfs_notify_dirent); +EXPORT_SYMBOL_GPL(kernfs_notify); void sysfs_notify(struct kobject *k, const char *dir, const char *attr) { - struct sysfs_dirent *sd = k->sd; - - mutex_lock(&sysfs_mutex); + struct sysfs_dirent *sd = k->sd, *tmp; if (sd && dir) - sd = sysfs_find_dirent(sd, dir, NULL); - if (sd && attr) - sd = sysfs_find_dirent(sd, attr, NULL); - if (sd) - sysfs_notify_dirent(sd); + sd = sysfs_get_dirent(sd, dir); + else + sysfs_get(sd); - mutex_unlock(&sysfs_mutex); + if (sd && attr) { + tmp = sysfs_get_dirent(sd, attr); + sysfs_put(sd); + sd = tmp; + } + + if (sd) { + kernfs_notify(sd); + sysfs_put(sd); + } } EXPORT_SYMBOL_GPL(sysfs_notify); diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index ba993eb..f20796e 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -84,6 +84,7 @@ int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent, const char *new_name, const void *new_ns); void kernfs_enable_ns(struct sysfs_dirent *sd); int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr); +void kernfs_notify(struct sysfs_dirent *sd); #else /* CONFIG_SYSFS */ @@ -120,6 +121,8 @@ static inline int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr) { return -ENOSYS; } +static inline void kernfs_notify(struct sysfs_dirent *sd) { } + #endif /* CONFIG_SYSFS */ static inline struct sysfs_dirent * diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 2bc735d..0ab2b02 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -243,7 +243,6 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, const char *link_name); void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr); -void sysfs_notify_dirent(struct sysfs_dirent *sd); struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, const unsigned char *name, const void *ns); @@ -418,9 +417,6 @@ static inline void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr) { } -static inline void sysfs_notify_dirent(struct sysfs_dirent *sd) -{ -} static inline struct sysfs_dirent * sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, const unsigned char *name, const void *ns) @@ -466,4 +462,9 @@ sysfs_get_dirent(struct sysfs_dirent *parent_sd, const unsigned char *name) return sysfs_get_dirent_ns(parent_sd, name, NULL); } +static inline void sysfs_notify_dirent(struct sysfs_dirent *sd) +{ + kernfs_notify(sd); +} + #endif /* _SYSFS_H_ */ -- 1.8.4.2