提交 3e519038 编写于 作者: T Tejun Heo 提交者: Greg Kroah-Hartman

sysfs: make sysfs_dirent->s_element a union

Make sd->s_element a union of sysfs_elem_{dir|symlink|attr|bin_attr}
and rename it to s_elem.  This is to achieve...

* some level of type checking : changing symlink to point to
  sysfs_dirent instead of kobject is much safer and less painful now.
* easier / standardized dereferencing
* allow sysfs_elem_* to contain more than one entry

Where possible, pointer is obtained by directly deferencing from sd
instead of going through other entities.  This reduces dependencies to
dentry, inode and kobject.  to_attr() and to_bin_attr() are unused now
and removed.

This is in preparation of object reference simplification.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 0c096b50
......@@ -23,7 +23,8 @@
static int
fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
{
struct bin_attribute * attr = to_bin_attr(dentry);
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);
if (!attr->read)
......@@ -65,7 +66,8 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
static int
flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
{
struct bin_attribute *attr = to_bin_attr(dentry);
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);
if (!attr->write)
......@@ -101,9 +103,9 @@ static ssize_t write(struct file *file, const char __user *userbuf,
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 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);
if (!attr->mmap)
return -EINVAL;
......@@ -114,7 +116,8 @@ 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 bin_attribute * attr = to_bin_attr(file->f_path.dentry);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
int error = -EINVAL;
if (!kobj || !attr)
......@@ -150,7 +153,8 @@ static int open(struct inode * inode, struct file * file)
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);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
u8 * buffer = file->private_data;
kobject_put(kobj);
......
......@@ -52,11 +52,8 @@ void release_sysfs_dirent(struct sysfs_dirent * sd)
repeat:
parent_sd = sd->s_parent;
if (sd->s_type & SYSFS_KOBJ_LINK) {
struct sysfs_symlink * sl = sd->s_element;
kobject_put(sl->target_kobj);
kfree(sl);
}
if (sd->s_type & SYSFS_KOBJ_LINK)
kobject_put(sd->s_elem.symlink.target_kobj);
if (sd->s_type & SYSFS_COPY_NAME)
kfree(sd->s_name);
kfree(sd->s_iattr);
......@@ -95,8 +92,7 @@ static struct dentry_operations sysfs_dentry_ops = {
.d_iput = sysfs_d_iput,
};
struct sysfs_dirent *sysfs_new_dirent(const char *name, void *element,
umode_t mode, int type)
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
{
char *dup_name = NULL;
struct sysfs_dirent *sd = NULL;
......@@ -120,7 +116,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, void *element,
INIT_LIST_HEAD(&sd->s_sibling);
sd->s_name = name;
sd->s_element = element;
sd->s_mode = mode;
sd->s_type = type;
......@@ -160,7 +155,7 @@ int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
struct sysfs_dirent * sd;
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (sd->s_element) {
if (sd->s_type) {
if (strcmp(sd->s_name, new))
continue;
else
......@@ -215,9 +210,10 @@ static int create_dir(struct kobject *kobj, struct dentry *parent,
goto out_dput;
error = -ENOMEM;
sd = sysfs_new_dirent(name, kobj, mode, SYSFS_DIR);
sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
if (!sd)
goto out_drop;
sd->s_elem.dir.kobj = kobj;
sysfs_attach_dirent(sd, parent->d_fsdata, dentry);
error = sysfs_create(dentry, mode, init_dir);
......@@ -290,10 +286,10 @@ static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
int error = 0;
if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
bin_attr = sd->s_element;
bin_attr = sd->s_elem.bin_attr.bin_attr;
attr = &bin_attr->attr;
} else {
attr = sd->s_element;
attr = sd->s_elem.attr.attr;
init = init_file;
}
......@@ -404,7 +400,7 @@ static void __sysfs_remove_dir(struct dentry *dentry)
mutex_lock(&dentry->d_inode->i_mutex);
parent_sd = dentry->d_fsdata;
list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
if (!sd->s_type || !(sd->s_type & SYSFS_NOT_PINNED))
continue;
list_del_init(&sd->s_sibling);
sysfs_drop_dentry(sd, dentry);
......@@ -556,7 +552,7 @@ static int sysfs_dir_open(struct inode *inode, struct file *file)
struct sysfs_dirent * sd;
mutex_lock(&dentry->d_inode->i_mutex);
sd = sysfs_new_dirent("_DIR_", NULL, 0, 0);
sd = sysfs_new_dirent("_DIR_", 0, 0);
if (sd)
sysfs_attach_dirent(sd, parent_sd, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
......@@ -623,7 +619,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
next = list_entry(p, struct sysfs_dirent,
s_sibling);
if (!next->s_element)
if (!next->s_type)
continue;
name = next->s_name;
......@@ -671,7 +667,7 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
struct sysfs_dirent *next;
next = list_entry(p, struct sysfs_dirent,
s_sibling);
if (next->s_element)
if (next->s_type)
n--;
p = p->next;
}
......@@ -738,9 +734,10 @@ struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
if (!shadow)
goto nomem;
sd = sysfs_new_dirent("_SHADOW_", kobj, inode->i_mode, SYSFS_DIR);
sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
if (!sd)
goto nomem;
sd->s_elem.dir.kobj = kobj;
/* point to parent_sd but don't attach to it */
sd->s_parent = sysfs_get(parent_sd);
sysfs_attach_dirent(sd, NULL, shadow);
......
......@@ -88,7 +88,6 @@ remove_from_collection(struct sysfs_buffer *buffer, struct inode *node)
static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
struct attribute * attr = to_attr(dentry);
struct kobject * kobj = to_kobj(dentry->d_parent);
struct sysfs_ops * ops = buffer->ops;
int ret = 0;
......@@ -100,7 +99,7 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
return -ENOMEM;
buffer->event = atomic_read(&sd->s_event);
count = ops->show(kobj,attr,buffer->page);
count = ops->show(kobj, sd->s_elem.attr.attr, buffer->page);
BUG_ON(count > (ssize_t)PAGE_SIZE);
if (count >= 0) {
buffer->needs_read_fill = 0;
......@@ -199,11 +198,11 @@ fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t
static int
flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count)
{
struct attribute * attr = to_attr(dentry);
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
struct kobject * kobj = to_kobj(dentry->d_parent);
struct sysfs_ops * ops = buffer->ops;
return ops->store(kobj,attr,buffer->page,count);
return ops->store(kobj, attr_sd->s_elem.attr.attr, buffer->page, count);
}
......@@ -248,7 +247,8 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t
static int sysfs_open_file(struct inode *inode, struct file *file)
{
struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
struct attribute * attr = to_attr(file->f_path.dentry);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct attribute *attr = attr_sd->s_elem.attr.attr;
struct sysfs_buffer_collection *set;
struct sysfs_buffer * buffer;
struct sysfs_ops * ops = NULL;
......@@ -341,15 +341,15 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
static int sysfs_release(struct inode * inode, struct file * filp)
{
struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent);
struct attribute * attr = to_attr(filp->f_path.dentry);
struct module * owner = attr->owner;
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;
if (buffer)
remove_from_collection(buffer, inode);
kobject_put(kobj);
/* After this point, attr should not be accessed. */
module_put(owner);
module_put(attr->owner);
if (buffer) {
if (buffer->page)
......@@ -454,11 +454,12 @@ int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
goto out_unlock;
}
sd = sysfs_new_dirent(attr->name, (void *)attr, mode, type);
sd = sysfs_new_dirent(attr->name, mode, type);
if (!sd) {
error = -ENOMEM;
goto out_unlock;
}
sd->s_elem.attr.attr = (void *)attr;
sysfs_attach_dirent(sd, parent_sd, NULL);
out_unlock:
......
......@@ -272,7 +272,7 @@ int sysfs_hash_and_remove(struct dentry * dir, const char * name)
parent_sd = dir->d_fsdata;
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (!sd->s_element)
if (!sd->s_type)
continue;
if (!strcmp(sd->s_name, name)) {
list_del_init(&sd->s_sibling);
......
......@@ -31,7 +31,6 @@ static struct sysfs_dirent sysfs_root = {
.s_count = ATOMIC_INIT(1),
.s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling),
.s_children = LIST_HEAD_INIT(sysfs_root.s_children),
.s_element = NULL,
.s_type = SYSFS_ROOT,
.s_iattr = NULL,
.s_ino = 1,
......
......@@ -48,30 +48,15 @@ static void fill_object_path(struct kobject * kobj, char * buffer, int length)
static int sysfs_add_link(struct dentry * parent, const char * name, struct kobject * target)
{
struct sysfs_dirent * parent_sd = parent->d_fsdata;
struct sysfs_symlink * sl;
struct sysfs_dirent * sd;
int error;
error = -ENOMEM;
sl = kzalloc(sizeof(*sl), GFP_KERNEL);
if (!sl)
goto err_out;
sl->target_kobj = kobject_get(target);
sd = sysfs_new_dirent(name, sl, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);
sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);
if (!sd)
goto err_out;
sysfs_attach_dirent(sd, parent_sd, NULL);
return -ENOMEM;
sd->s_elem.symlink.target_kobj = kobject_get(target);
sysfs_attach_dirent(sd, parent_sd, NULL);
return 0;
err_out:
if (sl) {
kobject_put(sl->target_kobj);
kfree(sl);
}
return error;
}
/**
......
struct sysfs_elem_dir {
struct kobject * kobj;
};
struct sysfs_elem_symlink {
struct kobject * target_kobj;
};
struct sysfs_elem_attr {
struct attribute * attr;
};
struct sysfs_elem_bin_attr {
struct bin_attribute * bin_attr;
};
struct sysfs_dirent {
atomic_t s_count;
struct sysfs_dirent * s_parent;
struct list_head s_sibling;
struct list_head s_children;
const char * s_name;
void * s_element;
union {
struct sysfs_elem_dir dir;
struct sysfs_elem_symlink symlink;
struct sysfs_elem_attr attr;
struct sysfs_elem_bin_attr bin_attr;
} s_elem;
int s_type;
umode_t s_mode;
ino_t s_ino;
......@@ -22,8 +45,8 @@ extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
extern void release_sysfs_dirent(struct sysfs_dirent * sd);
extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *);
extern struct sysfs_dirent *sysfs_new_dirent(const char *name, void *element,
umode_t mode, int type);
extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode,
int type);
extern void sysfs_attach_dirent(struct sysfs_dirent *sd,
struct sysfs_dirent *parent_sd,
struct dentry *dentry);
......@@ -47,10 +70,6 @@ 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_symlink {
struct kobject * target_kobj;
};
struct sysfs_buffer {
struct list_head associates;
size_t count;
......@@ -70,19 +89,7 @@ struct sysfs_buffer_collection {
static inline struct kobject * to_kobj(struct dentry * dentry)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
return ((struct kobject *) sd->s_element);
}
static inline struct attribute * to_attr(struct dentry * dentry)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
return ((struct attribute *) sd->s_element);
}
static inline struct bin_attribute * to_bin_attr(struct dentry * dentry)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
return ((struct bin_attribute *) sd->s_element);
return sd->s_elem.dir.kobj;
}
static inline struct kobject *sysfs_get_kobject(struct dentry *dentry)
......@@ -92,11 +99,10 @@ static inline struct kobject *sysfs_get_kobject(struct dentry *dentry)
spin_lock(&dcache_lock);
if (!d_unhashed(dentry)) {
struct sysfs_dirent * sd = dentry->d_fsdata;
if (sd->s_type & SYSFS_KOBJ_LINK) {
struct sysfs_symlink * sl = sd->s_element;
kobj = kobject_get(sl->target_kobj);
} else
kobj = kobject_get(sd->s_element);
if (sd->s_type & SYSFS_KOBJ_LINK)
kobj = kobject_get(sd->s_elem.symlink.target_kobj);
else
kobj = kobject_get(sd->s_elem.dir.kobj);
}
spin_unlock(&dcache_lock);
......
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