From 94bebf4d1b8e7719f0f3944c037a21cfd99a4af7 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Wed, 20 Dec 2006 10:52:44 +0100 Subject: Driver core: fix race in sysfs between sysfs_remove_file() and read()/write() This patch prevents a race between IO and removing a file from sysfs. It introduces a list of sysfs_buffers associated with a file at the inode. Upon removal of a file the list is walked and the buffers marked orphaned. IO to orphaned buffers fails with -ENODEV. The driver can safely free associated data structures or be unloaded. Signed-off-by: Oliver Neukum Acked-by: Maneesh Soni Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/sysfs.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index bd7cec295dab..39c623fdc277 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -33,6 +33,22 @@ struct sysfs_symlink { struct kobject * target_kobj; }; +struct sysfs_buffer { + struct list_head associates; + size_t count; + loff_t pos; + char * page; + struct sysfs_ops * ops; + struct semaphore sem; + int orphaned; + int needs_read_fill; + int event; +}; + +struct sysfs_buffer_collection { + struct list_head associates; +}; + static inline struct kobject * to_kobj(struct dentry * dentry) { struct sysfs_dirent * sd = dentry->d_fsdata; -- cgit v1.2.3-59-g8ed1b