From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936006AbXGKXsq (ORCPT ); Wed, 11 Jul 2007 19:48:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S935135AbXGKXfV (ORCPT ); Wed, 11 Jul 2007 19:35:21 -0400 Received: from mx2.suse.de ([195.135.220.15]:33360 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934958AbXGKXfS (ORCPT ); Wed, 11 Jul 2007 19:35:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Tejun Heo , Greg Kroah-Hartman Subject: [PATCH 34/61] sysfs: implement bin_buffer Date: Wed, 11 Jul 2007 16:31:53 -0700 Message-Id: <11841968951572-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.5.2.2 In-Reply-To: <11841968903726-git-send-email-gregkh@suse.de> References: <20070711233021.GA5253@kroah.com> <11841967403365-git-send-email-gregkh@suse.de> <11841967493890-git-send-email-gregkh@suse.de> <1184196753488-git-send-email-gregkh@suse.de> <1184196759393-git-send-email-gregkh@suse.de> <11841967633087-git-send-email-gregkh@suse.de> <11841967674155-git-send-email-gregkh@suse.de> <11841967711788-git-send-email-gregkh@suse.de> <11841967793134-git-send-email-gregkh@suse.de> <1184196783245-git-send-email-gregkh@suse.de> <1184196787247-git-send-email-gregkh@suse.de> <11841967992975-git-send-email-gregkh@suse.de> <11841968032469-git-send-email-gregkh@suse.de> <11841968071826-git-send-email-gregkh@suse.de> <11841968111201-git-send-email-gregkh@suse.de> <11841968151257-git-send-email-gregkh@suse.de> <1184196818497-git-send-email-gregkh@suse.de> <11841968231043-git-send-email-gregkh@suse.de> <11841968271925-git-send-email-gregkh@suse.de> <11841968303508-git-send-email-gregkh@suse.de> <11841968352439-git-send-email-gregkh@suse.de> <11841968392043-git-send-email-gregkh@suse.de> <11841968431153-git-send-email-gregkh@suse.de> <11841968471598-git-send-email-gregkh@suse.de> <11841968512510-git-send-email-gregkh@suse.de> <1184196856662-git-send-email-gregkh@suse.de> <1184196860992-git-send-email-gregkh@suse.de> <11841968643630-git-send-email-gregkh@suse.de> <11841968683554-git-send-email-gregkh@suse.de> <11841968731843-git-send-email-gregkh@suse.de> <11841968773426-git-send-email-gregkh@suse.de> <118419688284-git-send-email-gregkh@suse.de> <11841968872456-git-send-email-gregkh@suse.de> <11841968903726-git-send-email-gregkh@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Tejun Heo Implement bin_buffer which contains a mutex and pointer to PAGE_SIZE buffer to properly synchronize accesses to per-openfile buffer and prepare for immediate-kobj-disconnect. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/bin.c | 64 ++++++++++++++++++++++++++++++++++++++++++------------- 1 files changed, 49 insertions(+), 15 deletions(-) diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 67a0d50..5dc47fe 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -20,6 +20,11 @@ #include "sysfs.h" +struct bin_buffer { + struct mutex mutex; + void *buffer; +}; + static int fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) { @@ -36,7 +41,7 @@ fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) static ssize_t read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) { - char *buffer = file->private_data; + struct bin_buffer *bb = file->private_data; struct dentry *dentry = file->f_path.dentry; int size = dentry->d_inode->i_size; loff_t offs = *off; @@ -49,17 +54,23 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) count = size - offs; } - count = fill_read(dentry, buffer, offs, count); + mutex_lock(&bb->mutex); + + count = fill_read(dentry, bb->buffer, offs, count); if (count < 0) - return count; + goto out_unlock; - if (copy_to_user(userbuf, buffer, count)) - return -EFAULT; + if (copy_to_user(userbuf, bb->buffer, count)) { + count = -EFAULT; + goto out_unlock; + } pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); *off = offs + count; + out_unlock: + mutex_unlock(&bb->mutex); return count; } @@ -79,7 +90,7 @@ flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) static ssize_t write(struct file *file, const char __user *userbuf, size_t bytes, loff_t *off) { - char *buffer = file->private_data; + struct bin_buffer *bb = file->private_data; struct dentry *dentry = file->f_path.dentry; int size = dentry->d_inode->i_size; loff_t offs = *off; @@ -92,25 +103,38 @@ static ssize_t write(struct file *file, const char __user *userbuf, count = size - offs; } - if (copy_from_user(buffer, userbuf, count)) - return -EFAULT; + mutex_lock(&bb->mutex); + + if (copy_from_user(bb->buffer, userbuf, count)) { + count = -EFAULT; + goto out_unlock; + } - count = flush_write(dentry, buffer, offs, count); + count = flush_write(dentry, bb->buffer, offs, count); if (count > 0) *off = offs + count; + + out_unlock: + mutex_unlock(&bb->mutex); return count; } static int mmap(struct file *file, struct vm_area_struct *vma) { + struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; struct kobject *kobj = to_kobj(file->f_path.dentry->d_parent); + int rc; if (!attr->mmap) return -EINVAL; - return attr->mmap(kobj, attr, vma); + mutex_lock(&bb->mutex); + rc = attr->mmap(kobj, attr, vma); + mutex_unlock(&bb->mutex); + + return rc; } static int open(struct inode * inode, struct file * file) @@ -118,6 +142,7 @@ static int open(struct inode * inode, struct file * file) struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent); struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; + struct bin_buffer *bb = NULL; int error = -EINVAL; if (!kobj || !attr) @@ -135,14 +160,22 @@ static int open(struct inode * inode, struct file * file) goto Error; error = -ENOMEM; - file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!file->private_data) + bb = kzalloc(sizeof(*bb), GFP_KERNEL); + if (!bb) goto Error; + bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!bb->buffer) + goto Error; + + mutex_init(&bb->mutex); + file->private_data = bb; + error = 0; - goto Done; + goto Done; Error: + kfree(bb); module_put(attr->attr.owner); Done: if (error) @@ -155,11 +188,12 @@ static int release(struct inode * inode, struct file * file) struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent); struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; - u8 * buffer = file->private_data; + struct bin_buffer *bb = file->private_data; kobject_put(kobj); module_put(attr->attr.owner); - kfree(buffer); + kfree(bb->buffer); + kfree(bb); return 0; } -- 1.5.2.2