diff options
Diffstat (limited to 'fs/sysfs/bin.c')
-rw-r--r-- | fs/sysfs/bin.c | 95 |
1 files changed, 62 insertions, 33 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 5dc47fe5..618b8ae 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -23,6 +23,7 @@ struct bin_buffer { struct mutex mutex; void *buffer; + int mmapped; }; static int @@ -30,12 +31,20 @@ fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) { struct sysfs_dirent *attr_sd = dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; - struct kobject * kobj = to_kobj(dentry->d_parent); + struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + int rc; + + /* need attr_sd for attr, its parent for kobj */ + if (!sysfs_get_active_two(attr_sd)) + return -ENODEV; - if (!attr->read) - return -EIO; + rc = -EIO; + if (attr->read) + rc = attr->read(kobj, buffer, off, count); - return attr->read(kobj, buffer, off, count); + sysfs_put_active_two(attr_sd); + + return rc; } static ssize_t @@ -79,12 +88,20 @@ flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) { struct sysfs_dirent *attr_sd = dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; - struct kobject *kobj = to_kobj(dentry->d_parent); + struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + int rc; + + /* need attr_sd for attr, its parent for kobj */ + if (!sysfs_get_active_two(attr_sd)) + return -ENODEV; - if (!attr->write) - return -EIO; + rc = -EIO; + if (attr->write) + rc = attr->write(kobj, buffer, offset, count); - return attr->write(kobj, buffer, offset, count); + sysfs_put_active_two(attr_sd); + + return rc; } static ssize_t write(struct file *file, const char __user *userbuf, @@ -124,14 +141,24 @@ 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); + struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; int rc; - if (!attr->mmap) - return -EINVAL; - mutex_lock(&bb->mutex); - rc = attr->mmap(kobj, attr, vma); + + /* need attr_sd for attr, its parent for kobj */ + if (!sysfs_get_active_two(attr_sd)) + return -ENODEV; + + rc = -EINVAL; + if (attr->mmap) + rc = attr->mmap(kobj, attr, vma); + + if (rc == 0 && !bb->mmapped) + bb->mmapped = 1; + else + sysfs_put_active_two(attr_sd); + mutex_unlock(&bb->mutex); return rc; @@ -139,58 +166,60 @@ static int mmap(struct file *file, struct vm_area_struct *vma) 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; + int error; - if (!kobj || !attr) - goto Done; + /* need attr_sd for attr */ + if (!sysfs_get_active(attr_sd)) + return -ENODEV; - /* Grab the module reference for this attribute if we have one */ + /* Grab the module reference for this attribute */ error = -ENODEV; - if (!try_module_get(attr->attr.owner)) - goto Done; + if (!try_module_get(attr->attr.owner)) + goto err_sput; error = -EACCES; if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) - goto Error; + goto err_mput; if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) - goto Error; + goto err_mput; error = -ENOMEM; bb = kzalloc(sizeof(*bb), GFP_KERNEL); if (!bb) - goto Error; + goto err_mput; bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!bb->buffer) - goto Error; + goto err_mput; mutex_init(&bb->mutex); file->private_data = bb; - error = 0; - goto Done; + /* open succeeded, put active reference and pin attr_sd */ + sysfs_put_active(attr_sd); + sysfs_get(attr_sd); + return 0; - Error: - kfree(bb); + err_mput: module_put(attr->attr.owner); - Done: - if (error) - kobject_put(kobj); + err_sput: + sysfs_put_active(attr_sd); + kfree(bb); return error; } 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; struct bin_buffer *bb = file->private_data; - kobject_put(kobj); + if (bb->mmapped) + sysfs_put_active_two(attr_sd); + sysfs_put(attr_sd); module_put(attr->attr.owner); kfree(bb->buffer); kfree(bb); |