1 files changed, 124 insertions, 71 deletions

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index d3b9f5f07db1..135353f8a296 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -20,29 +20,41 @@
 
 #include "sysfs.h"
 
+struct bin_buffer {
+        struct mutex    mutex;
+        void            *buffer;
+        int             mmapped;
+};
+
 static int
 fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
 {
-        struct bin_attribute * attr = to_bin_attr(dentry);
-        struct kobject * kobj = to_kobj(dentry->d_parent);
+        struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+        struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+        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, attr, buffer, off, count);
 
-        return attr->read(kobj, buffer, off, count);
+        sysfs_put_active_two(attr_sd);
+
+        return rc;
 }
 
 static ssize_t
-read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
+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;
-        int ret;
-
-        if (count > PAGE_SIZE)
-                count = PAGE_SIZE;
+        int count = min_t(size_t, bytes, PAGE_SIZE);
 
         if (size) {
                 if (offs > size)
@@ -51,43 +63,56 @@ read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
                         count = size - offs;
         }
 
-        ret = fill_read(dentry, buffer, offs, count);
-        if (ret < 0) 
-                return ret;
-        count = ret;
+        mutex_lock(&bb->mutex);
+
+        count = fill_read(dentry, bb->buffer, offs, count);
+        if (count < 0)
+                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 = %zd\n", offs, *off, count);
+        pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
 
         *off = offs + count;
 
+ out_unlock:
+        mutex_unlock(&bb->mutex);
         return count;
 }
 
 static int
 flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
 {
-        struct bin_attribute *attr = to_bin_attr(dentry);
-        struct kobject *kobj = to_kobj(dentry->d_parent);
+        struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+        struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+        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;
+
+        rc = -EIO;
+        if (attr->write)
+                rc = attr->write(kobj, attr, buffer, offset, count);
 
-        if (!attr->write)
-                return -EIO;
+        sysfs_put_active_two(attr_sd);
 
-        return attr->write(kobj, buffer, offset, count);
+        return rc;
 }
 
-static ssize_t write(struct file * file, const char __user * userbuf,
-                     size_t count, loff_t * off)
+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;
+        int count = min_t(size_t, bytes, PAGE_SIZE);
 
-        if (count > PAGE_SIZE)
-                count = PAGE_SIZE;
         if (size) {
                 if (offs > size)
                         return 0;
@@ -95,72 +120,100 @@ 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);
 
-        count = flush_write(dentry, buffer, offs, count);
+        if (copy_from_user(bb->buffer, userbuf, count)) {
+                count = -EFAULT;
+                goto out_unlock;
+        }
+
+        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 dentry *dentry = file->f_path.dentry;
-        struct bin_attribute *attr = to_bin_attr(dentry);
-        struct kobject *kobj = to_kobj(dentry->d_parent);
+        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 = attr_sd->s_parent->s_elem.dir.kobj;
+        int rc;
+
+        mutex_lock(&bb->mutex);
+
+        /* need attr_sd for attr, its parent for kobj */
+        if (!sysfs_get_active_two(attr_sd))
+                return -ENODEV;
 
-        if (!attr->mmap)
-                return -EINVAL;
+        rc = -EINVAL;
+        if (attr->mmap)
+                rc = attr->mmap(kobj, attr, vma);
 
-        return 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;
 }
 
 static int open(struct inode * inode, struct file * file)
 {
-        struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
-        struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
-        int error = -EINVAL;
-
-        if (!kobj || !attr)
-                goto Done;
+        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;
 
-        /* Grab the module reference for this attribute if we have one */
-        error = -ENODEV;
-        if (!try_module_get(attr->attr.owner)) 
-                goto Done;
+        /* need attr_sd for attr */
+        if (!sysfs_get_active(attr_sd))
+                return -ENODEV;
 
         error = -EACCES;
         if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
-                goto Error;
+                goto err_out;
         if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
-                goto Error;
+                goto err_out;
 
         error = -ENOMEM;
-        file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
-        if (!file->private_data)
-                goto Error;
-
-        error = 0;
-    goto Done;
-
- Error:
-        module_put(attr->attr.owner);
- Done:
-        if (error)
-                kobject_put(kobj);
+        bb = kzalloc(sizeof(*bb), GFP_KERNEL);
+        if (!bb)
+                goto err_out;
+
+        bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+        if (!bb->buffer)
+                goto err_out;
+
+        mutex_init(&bb->mutex);
+        file->private_data = bb;
+
+        /* open succeeded, put active reference and pin attr_sd */
+        sysfs_put_active(attr_sd);
+        sysfs_get(attr_sd);
+        return 0;
+
+ err_out:
+        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 bin_attribute * attr = to_bin_attr(file->f_path.dentry);
-        u8 * buffer = file->private_data;
-
-        kobject_put(kobj);
-        module_put(attr->attr.owner);
-        kfree(buffer);
+        struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+        struct bin_buffer *bb = file->private_data;
+
+        if (bb->mmapped)
+                sysfs_put_active_two(attr_sd);
+        sysfs_put(attr_sd);
+        kfree(bb->buffer);
+        kfree(bb);
         return 0;
 }
 
@@ -181,9 +234,9 @@ const struct file_operations bin_fops = {
 
 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 {
-        BUG_ON(!kobj || !kobj->dentry || !attr);
+        BUG_ON(!kobj || !kobj->sd || !attr);
 
-        return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
+        return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
 }
 
 
@@ -195,7 +248,7 @@ int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 
 void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 {
-        if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
+        if (sysfs_hash_and_remove(kobj->sd, attr->attr.name) < 0) {
                 printk(KERN_ERR "%s: "
                         "bad dentry or inode or no such file: \"%s\"\n",
                         __FUNCTION__, attr->attr.name);