From 7b595756ec1f49e0049a9e01a1298d53a7faaa15 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 14 Jun 2007 03:45:17 +0900 Subject: sysfs: kill unnecessary attribute->owner sysfs is now completely out of driver/module lifetime game. After deletion, a sysfs node doesn't access anything outside sysfs proper, so there's no reason to hold onto the attribute owners. Note that often the wrong modules were accounted for as owners leading to accessing removed modules. This patch kills now unnecessary attribute->owner. Note that with this change, userland holding a sysfs node does not prevent the backing module from being unloaded. For more info regarding lifetime rule cleanup, please read the following message. http://article.gmane.org/gmane.linux.kernel/510293 (tweaked by Greg to not delete the field just yet, to make it easier to merge things properly.) Signed-off-by: Tejun Heo Cc: Cornelia Huck Cc: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/bin.c | 19 +++++-------------- fs/sysfs/file.c | 21 +++++---------------- 2 files changed, 10 insertions(+), 30 deletions(-) (limited to 'fs/sysfs') diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 618b8aea6a7..3c5574a40b0 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -175,25 +175,20 @@ static int open(struct inode * inode, struct file * file) if (!sysfs_get_active(attr_sd)) return -ENODEV; - /* Grab the module reference for this attribute */ - error = -ENODEV; - if (!try_module_get(attr->attr.owner)) - goto err_sput; - error = -EACCES; if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) - goto err_mput; + goto err_out; if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) - goto err_mput; + goto err_out; error = -ENOMEM; bb = kzalloc(sizeof(*bb), GFP_KERNEL); if (!bb) - goto err_mput; + goto err_out; bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!bb->buffer) - goto err_mput; + goto err_out; mutex_init(&bb->mutex); file->private_data = bb; @@ -203,9 +198,7 @@ static int open(struct inode * inode, struct file * file) sysfs_get(attr_sd); return 0; - err_mput: - module_put(attr->attr.owner); - err_sput: + err_out: sysfs_put_active(attr_sd); kfree(bb); return error; @@ -214,13 +207,11 @@ static int open(struct inode * inode, struct file * file) static int release(struct inode * inode, struct file * file) { 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 = file->private_data; if (bb->mmapped) sysfs_put_active_two(attr_sd); sysfs_put(attr_sd); - module_put(attr->attr.owner); kfree(bb->buffer); kfree(bb); return 0; diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index d673d9b5d33..a84b734f7b2 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -241,7 +241,6 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t static int sysfs_open_file(struct inode *inode, struct file *file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct attribute *attr = attr_sd->s_elem.attr.attr; struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; struct sysfs_buffer * buffer; struct sysfs_ops * ops = NULL; @@ -251,11 +250,6 @@ static int sysfs_open_file(struct inode *inode, struct file *file) if (!sysfs_get_active_two(attr_sd)) return -ENODEV; - /* Grab the module reference for this attribute */ - error = -ENODEV; - if (!try_module_get(attr->owner)) - goto err_sput; - /* if the kobject has no ktype, then we assume that it is a subsystem * itself, and use ops for it. */ @@ -272,7 +266,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) * or the subsystem have no operations. */ if (!ops) - goto err_mput; + goto err_out; /* File needs write support. * The inode's perms must say it's ok, @@ -280,7 +274,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) */ if (file->f_mode & FMODE_WRITE) { if (!(inode->i_mode & S_IWUGO) || !ops->store) - goto err_mput; + goto err_out; } /* File needs read support. @@ -289,7 +283,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) */ if (file->f_mode & FMODE_READ) { if (!(inode->i_mode & S_IRUGO) || !ops->show) - goto err_mput; + goto err_out; } /* No error? Great, allocate a buffer for the file, and store it @@ -298,7 +292,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) error = -ENOMEM; buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL); if (!buffer) - goto err_mput; + goto err_out; init_MUTEX(&buffer->sem); buffer->needs_read_fill = 1; @@ -310,9 +304,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) sysfs_get(attr_sd); return 0; - err_mput: - module_put(attr->owner); - err_sput: + err_out: sysfs_put_active_two(attr_sd); return error; } @@ -320,12 +312,9 @@ static int sysfs_open_file(struct inode *inode, struct file *file) static int sysfs_release(struct inode * inode, struct file * filp) { struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; - struct attribute *attr = attr_sd->s_elem.attr.attr; struct sysfs_buffer *buffer = filp->private_data; sysfs_put(attr_sd); - /* After this point, attr should not be accessed. */ - module_put(attr->owner); if (buffer) { if (buffer->page) -- cgit v1.2.3