[PATCH 36/61] sysfs: kill attribute file orphaning

Greg Kroah-Hartman
2007-07-11T23:49:44Z

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>
---
fs/sysfs/file.c | 65 ++++++++++-------------------------------------------
fs/sysfs/inode.c | 25 --------------------
fs/sysfs/mount.c | 8 ------
fs/sysfs/sysfs.h | 16 -------------
4 files changed, 13 insertions(+), 101 deletions(-)

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 310430b..d673d9b 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 7b9a8f1..d9ccc83 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 8f6d8b1..37ff9ff 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 d998e8e..8b09e9d 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) {
--
1.5.2.2