sysfs: kill attribute file orphaning

Now that sysfs_dirent can be disconnected from kobject on deletion,
there is no need to orphan each attribute files.  All [bin_]attribute
nodes are automatically orphaned when the parent node is deleted.
Kill attribute file orphaning.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 13 insertions, 101 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 310430baf57..d673d9b5d33 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -50,29 +50,15 @@ static struct sysfs_ops subsys_sysfs_ops = {
         .store  = subsys_attr_store,
 };
 
-/**
- *      add_to_collection - add buffer to a collection
- *      @buffer:        buffer to be added
- *      @node:          inode of set to add to
- */
-
-static inline void
-add_to_collection(struct sysfs_buffer *buffer, struct inode *node)
-{
-        struct sysfs_buffer_collection *set = node->i_private;
-
-        mutex_lock(&node->i_mutex);
-        list_add(&buffer->associates, &set->associates);
-        mutex_unlock(&node->i_mutex);
-}
-
-static inline void
-remove_from_collection(struct sysfs_buffer *buffer, struct inode *node)
-{
-        mutex_lock(&node->i_mutex);
-        list_del(&buffer->associates);
-        mutex_unlock(&node->i_mutex);
-}
+struct sysfs_buffer {
+        size_t                  count;
+        loff_t                  pos;
+        char                    * page;
+        struct sysfs_ops        * ops;
+        struct semaphore        sem;
+        int                     needs_read_fill;
+        int                     event;
+};
 
 /**
  *      fill_read_buffer - allocate and fill buffer from object.
@@ -144,10 +130,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 
         down(&buffer->sem);
         if (buffer->needs_read_fill) {
-                if (buffer->orphaned)
-                        retval = -ENODEV;
-                else
-                        retval = fill_read_buffer(file->f_path.dentry,buffer);
+                retval = fill_read_buffer(file->f_path.dentry,buffer);
                 if (retval)
                         goto out;
         }
@@ -246,16 +229,11 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t
         ssize_t len;
 
         down(&buffer->sem);
-        if (buffer->orphaned) {
-                len = -ENODEV;
-                goto out;
-        }
         len = fill_write_buffer(buffer, buf, count);
         if (len > 0)
                 len = flush_write_buffer(file->f_path.dentry, buffer, len);
         if (len > 0)
                 *ppos += len;
-out:
         up(&buffer->sem);
         return len;
 }
@@ -265,7 +243,6 @@ 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_collection *set;
         struct sysfs_buffer * buffer;
         struct sysfs_ops * ops = NULL;
         int error;
@@ -289,26 +266,14 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
         else
                 ops = &subsys_sysfs_ops;
 
+        error = -EACCES;
+
         /* No sysfs operations, either from having no subsystem,
          * or the subsystem have no operations.
          */
-        error = -EACCES;
         if (!ops)
                 goto err_mput;
 
-        /* make sure we have a collection to add our buffers to */
-        mutex_lock(&inode->i_mutex);
-        if (!(set = inode->i_private)) {
-                error = -ENOMEM;
-                if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL)))
-                        goto err_mput;
-                else
-                        INIT_LIST_HEAD(&set->associates);
-        }
-        mutex_unlock(&inode->i_mutex);
-
-        error = -EACCES;
-
         /* File needs write support.
          * The inode's perms must say it's ok, 
          * and we must have a store method.
@@ -335,11 +300,9 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
         if (!buffer)
                 goto err_mput;
 
-        INIT_LIST_HEAD(&buffer->associates);
         init_MUTEX(&buffer->sem);
         buffer->needs_read_fill = 1;
         buffer->ops = ops;
-        add_to_collection(buffer, inode);
         file->private_data = buffer;
 
         /* open succeeded, put active references and pin attr_sd */
@@ -358,10 +321,8 @@ 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;
+        struct sysfs_buffer *buffer = filp->private_data;
 
-        if (buffer)
-                remove_from_collection(buffer, inode);
         sysfs_put(attr_sd);
         /* After this point, attr should not be accessed. */
         module_put(attr->owner);
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 7b9a8f132d5..d9ccc830b73 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -191,24 +191,6 @@ int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
         return error;
 }
 
-static inline void orphan_all_buffers(struct inode *node)
-{
-        struct sysfs_buffer_collection *set;
-        struct sysfs_buffer *buf;
-
-        mutex_lock_nested(&node->i_mutex, I_MUTEX_CHILD);
-        set = node->i_private;
-        if (set) {
-                list_for_each_entry(buf, &set->associates, associates) {
-                        down(&buf->sem);
-                        buf->orphaned = 1;
-                        up(&buf->sem);
-                }
-        }
-        mutex_unlock(&node->i_mutex);
-}
-
-
 /*
  * Unhashes the dentry corresponding to given sysfs_dirent
  * Called with parent inode's i_mutex held.
@@ -216,7 +198,6 @@ static inline void orphan_all_buffers(struct inode *node)
 void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
 {
         struct dentry *dentry = NULL;
-        struct inode *inode;
 
         /* We're not holding a reference to ->s_dentry dentry but the
          * field will stay valid as long as sysfs_lock is held.
@@ -236,17 +217,11 @@ void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
                 spin_lock(&dcache_lock);
                 spin_lock(&dentry->d_lock);
                 if (!d_unhashed(dentry) && dentry->d_inode) {
-                        inode = dentry->d_inode;
-                        spin_lock(&inode->i_lock);
-                        __iget(inode);
-                        spin_unlock(&inode->i_lock);
                         dget_locked(dentry);
                         __d_drop(dentry);
                         spin_unlock(&dentry->d_lock);
                         spin_unlock(&dcache_lock);
                         simple_unlink(parent->d_inode, dentry);
-                        orphan_all_buffers(inode);
-                        iput(inode);
                 } else {
                         spin_unlock(&dentry->d_lock);
                         spin_unlock(&dcache_lock);
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 8f6d8b1b211..37ff9ffc55f 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -19,12 +19,9 @@ struct vfsmount *sysfs_mount;
 struct super_block * sysfs_sb = NULL;
 struct kmem_cache *sysfs_dir_cachep;
 
-static void sysfs_clear_inode(struct inode *inode);
-
 static const struct super_operations sysfs_ops = {
         .statfs         = simple_statfs,
         .drop_inode     = sysfs_delete_inode,
-        .clear_inode    = sysfs_clear_inode,
 };
 
 static struct sysfs_dirent sysfs_root = {
@@ -36,11 +33,6 @@ static struct sysfs_dirent sysfs_root = {
         .s_ino          = 1,
 };
 
-static void sysfs_clear_inode(struct inode *inode)
-{
-        kfree(inode->i_private);
-}
-
 static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
 {
         struct inode *inode;
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index d998e8e2784..8b09e9d882c 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -88,22 +88,6 @@ extern const struct file_operations bin_fops;
 extern const struct inode_operations sysfs_dir_inode_operations;
 extern const struct inode_operations sysfs_symlink_inode_operations;
 
-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 sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
 {
         if (sd) {