1 files changed, 62 insertions, 33 deletions

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 5dc47fe5de5e..618b8aea6a7b 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);