#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/namei.h>
+#include <linux/idr.h>
#include <asm/semaphore.h>
#include "sysfs.h"
DECLARE_RWSEM(sysfs_rename_sem);
+spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED;
+spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
+
+static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_IDA(sysfs_ino_ida);
+
+int sysfs_alloc_ino(ino_t *pino)
+{
+ int ino, rc;
+
+ retry:
+ spin_lock(&sysfs_ino_lock);
+ rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
+ spin_unlock(&sysfs_ino_lock);
+
+ if (rc == -EAGAIN) {
+ if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
+ goto retry;
+ rc = -ENOMEM;
+ }
+
+ *pino = ino;
+ return rc;
+}
+
+static void sysfs_free_ino(ino_t ino)
+{
+ spin_lock(&sysfs_ino_lock);
+ ida_remove(&sysfs_ino_ida, ino);
+ spin_unlock(&sysfs_ino_lock);
+}
+
+void release_sysfs_dirent(struct sysfs_dirent * sd)
+{
+ struct sysfs_dirent *parent_sd;
+
+ repeat:
+ parent_sd = sd->s_parent;
+
+ if (sd->s_type & SYSFS_KOBJ_LINK)
+ sysfs_put(sd->s_elem.symlink.target_sd);
+ if (sd->s_type & SYSFS_COPY_NAME)
+ kfree(sd->s_name);
+ kfree(sd->s_iattr);
+ sysfs_free_ino(sd->s_ino);
+ kmem_cache_free(sysfs_dir_cachep, sd);
+
+ sd = parent_sd;
+ if (sd && atomic_dec_and_test(&sd->s_count))
+ goto repeat;
+}
static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
if (sd) {
- BUG_ON(sd->s_dentry != dentry);
- sd->s_dentry = NULL;
+ /* sd->s_dentry is protected with sysfs_lock. This
+ * allows sysfs_drop_dentry() to dereference it.
+ */
+ spin_lock(&sysfs_lock);
+
+ /* The dentry might have been deleted or another
+ * lookup could have happened updating sd->s_dentry to
+ * point the new dentry. Ignore if it isn't pointing
+ * to this dentry.
+ */
+ if (sd->s_dentry == dentry)
+ sd->s_dentry = NULL;
+ spin_unlock(&sysfs_lock);
sysfs_put(sd);
}
iput(inode);
.d_iput = sysfs_d_iput,
};
-/*
- * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
- */
-static struct sysfs_dirent * __sysfs_new_dirent(void * element)
+struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
{
- struct sysfs_dirent * sd;
+ char *dup_name = NULL;
+ struct sysfs_dirent *sd = NULL;
+
+ if (type & SYSFS_COPY_NAME) {
+ name = dup_name = kstrdup(name, GFP_KERNEL);
+ if (!name)
+ goto err_out;
+ }
sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
if (!sd)
- return NULL;
+ goto err_out;
+
+ if (sysfs_alloc_ino(&sd->s_ino))
+ goto err_out;
atomic_set(&sd->s_count, 1);
atomic_set(&sd->s_event, 1);
INIT_LIST_HEAD(&sd->s_children);
INIT_LIST_HEAD(&sd->s_sibling);
- sd->s_element = element;
+
+ sd->s_name = name;
+ sd->s_mode = mode;
+ sd->s_type = type;
return sd;
-}
-static void __sysfs_list_dirent(struct sysfs_dirent *parent_sd,
- struct sysfs_dirent *sd)
-{
- if (sd)
- list_add(&sd->s_sibling, &parent_sd->s_children);
+ err_out:
+ kfree(dup_name);
+ kmem_cache_free(sysfs_dir_cachep, sd);
+ return NULL;
}
-static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent *parent_sd,
- void * element)
+void sysfs_attach_dirent(struct sysfs_dirent *sd,
+ struct sysfs_dirent *parent_sd, struct dentry *dentry)
{
- struct sysfs_dirent *sd;
- sd = __sysfs_new_dirent(element);
- __sysfs_list_dirent(parent_sd, sd);
- return sd;
+ if (dentry) {
+ sd->s_dentry = dentry;
+ dentry->d_fsdata = sysfs_get(sd);
+ dentry->d_op = &sysfs_dentry_ops;
+ }
+
+ if (parent_sd) {
+ sd->s_parent = sysfs_get(parent_sd);
+ list_add(&sd->s_sibling, &parent_sd->s_children);
+ }
}
/*
struct sysfs_dirent * sd;
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
- if (sd->s_element) {
- const unsigned char *existing = sysfs_get_name(sd);
- if (strcmp(existing, new))
+ if (sd->s_type) {
+ if (strcmp(sd->s_name, new))
continue;
else
return -EEXIST;
return 0;
}
-
-static struct sysfs_dirent *
-__sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type)
-{
- struct sysfs_dirent * sd;
-
- sd = __sysfs_new_dirent(element);
- if (!sd)
- goto out;
-
- sd->s_mode = mode;
- sd->s_type = type;
- sd->s_dentry = dentry;
- if (dentry) {
- dentry->d_fsdata = sysfs_get(sd);
- dentry->d_op = &sysfs_dentry_ops;
- }
-
-out:
- return sd;
-}
-
-int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
- void * element, umode_t mode, int type)
-{
- struct sysfs_dirent *sd;
-
- sd = __sysfs_make_dirent(dentry, element, mode, type);
- __sysfs_list_dirent(parent_sd, sd);
-
- return sd ? 0 : -ENOMEM;
-}
-
static int init_dir(struct inode * inode)
{
inode->i_op = &sysfs_dir_inode_operations;
return 0;
}
-static int create_dir(struct kobject * k, struct dentry * p,
- const char * n, struct dentry ** d)
+static int create_dir(struct kobject *kobj, struct dentry *parent,
+ const char *name, struct dentry **p_dentry)
{
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
+ struct dentry *dentry;
+ struct sysfs_dirent *sd;
- mutex_lock(&p->d_inode->i_mutex);
- *d = lookup_one_len(n, p, strlen(n));
- if (!IS_ERR(*d)) {
- if (sysfs_dirent_exist(p->d_fsdata, n))
- error = -EEXIST;
- else
- error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
- SYSFS_DIR);
- if (!error) {
- error = sysfs_create(*d, mode, init_dir);
- if (!error) {
- inc_nlink(p->d_inode);
- (*d)->d_op = &sysfs_dentry_ops;
- d_rehash(*d);
- }
- }
- if (error && (error != -EEXIST)) {
- struct sysfs_dirent *sd = (*d)->d_fsdata;
- if (sd) {
- list_del_init(&sd->s_sibling);
- sysfs_put(sd);
- }
- d_drop(*d);
- }
- dput(*d);
- } else
- error = PTR_ERR(*d);
- mutex_unlock(&p->d_inode->i_mutex);
+ mutex_lock(&parent->d_inode->i_mutex);
+
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (IS_ERR(dentry)) {
+ error = PTR_ERR(dentry);
+ goto out_unlock;
+ }
+
+ error = -EEXIST;
+ if (sysfs_dirent_exist(parent->d_fsdata, name))
+ goto out_dput;
+
+ error = -ENOMEM;
+ 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);
+ if (error)
+ goto out_sput;
+
+ inc_nlink(parent->d_inode);
+ dentry->d_op = &sysfs_dentry_ops;
+ d_rehash(dentry);
+
+ *p_dentry = dentry;
+ error = 0;
+ goto out_dput;
+
+ out_sput:
+ list_del_init(&sd->s_sibling);
+ sysfs_put(sd);
+ out_drop:
+ d_drop(dentry);
+ out_dput:
+ dput(dentry);
+ out_unlock:
+ mutex_unlock(&parent->d_inode->i_mutex);
return error;
}
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;
}
dentry->d_fsdata = sysfs_get(sd);
+ /* protect sd->s_dentry against sysfs_d_iput */
+ spin_lock(&sysfs_lock);
sd->s_dentry = dentry;
+ spin_unlock(&sysfs_lock);
error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
if (error) {
sysfs_put(sd);
int err = 0;
dentry->d_fsdata = sysfs_get(sd);
+ /* protect sd->s_dentry against sysfs_d_iput */
+ spin_lock(&sysfs_lock);
sd->s_dentry = dentry;
+ spin_unlock(&sysfs_lock);
err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
if (!err) {
dentry->d_op = &sysfs_dentry_ops;
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (sd->s_type & SYSFS_NOT_PINNED) {
- const unsigned char * name = sysfs_get_name(sd);
-
- if (strcmp(name, dentry->d_name.name))
+ if (strcmp(sd->s_name, dentry->d_name.name))
continue;
if (sd->s_type & SYSFS_KOBJ_LINK)
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);
void sysfs_remove_dir(struct kobject * kobj)
{
- __sysfs_remove_dir(kobj->dentry);
+ struct dentry *d = kobj->dentry;
+
+ spin_lock(&kobj_sysfs_assoc_lock);
kobj->dentry = NULL;
+ spin_unlock(&kobj_sysfs_assoc_lock);
+
+ __sysfs_remove_dir(d);
}
int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent,
const char *new_name)
{
- int error = 0;
- struct dentry * new_dentry;
+ struct sysfs_dirent *sd = kobj->dentry->d_fsdata;
+ struct sysfs_dirent *parent_sd = new_parent->d_fsdata;
+ struct dentry *new_dentry;
+ char *dup_name;
+ int error;
if (!new_parent)
return -EFAULT;
mutex_lock(&new_parent->d_inode->i_mutex);
new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
- if (!IS_ERR(new_dentry)) {
- /* By allowing two different directories with the
- * same d_parent we allow this routine to move
- * between different shadows of the same directory
- */
- if (kobj->dentry->d_parent->d_inode != new_parent->d_inode)
- return -EINVAL;
- else if (new_dentry->d_parent->d_inode != new_parent->d_inode)
- error = -EINVAL;
- else if (new_dentry == kobj->dentry)
- error = -EINVAL;
- else if (!new_dentry->d_inode) {
- error = kobject_set_name(kobj, "%s", new_name);
- if (!error) {
- struct sysfs_dirent *sd, *parent_sd;
-
- d_add(new_dentry, NULL);
- d_move(kobj->dentry, new_dentry);
-
- sd = kobj->dentry->d_fsdata;
- parent_sd = new_parent->d_fsdata;
-
- list_del_init(&sd->s_sibling);
- list_add(&sd->s_sibling, &parent_sd->s_children);
- }
- else
- d_drop(new_dentry);
- } else
- error = -EEXIST;
- dput(new_dentry);
+ if (IS_ERR(new_dentry)) {
+ error = PTR_ERR(new_dentry);
+ goto out_unlock;
}
+
+ /* By allowing two different directories with the same
+ * d_parent we allow this routine to move between different
+ * shadows of the same directory
+ */
+ error = -EINVAL;
+ if (kobj->dentry->d_parent->d_inode != new_parent->d_inode ||
+ new_dentry->d_parent->d_inode != new_parent->d_inode ||
+ new_dentry == kobj->dentry)
+ goto out_dput;
+
+ error = -EEXIST;
+ if (new_dentry->d_inode)
+ goto out_dput;
+
+ /* rename kobject and sysfs_dirent */
+ error = -ENOMEM;
+ new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+ if (!new_name)
+ goto out_drop;
+
+ error = kobject_set_name(kobj, "%s", new_name);
+ if (error)
+ goto out_free;
+
+ kfree(sd->s_name);
+ sd->s_name = new_name;
+
+ /* move under the new parent */
+ d_add(new_dentry, NULL);
+ d_move(kobj->dentry, new_dentry);
+
+ list_del_init(&sd->s_sibling);
+ list_add(&sd->s_sibling, &parent_sd->s_children);
+
+ error = 0;
+ goto out_unlock;
+
+ out_free:
+ kfree(dup_name);
+ out_drop:
+ d_drop(new_dentry);
+ out_dput:
+ dput(new_dentry);
+ out_unlock:
mutex_unlock(&new_parent->d_inode->i_mutex);
up_write(&sysfs_rename_sem);
-
return error;
}
{
struct dentry * dentry = file->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
+ struct sysfs_dirent * sd;
mutex_lock(&dentry->d_inode->i_mutex);
- file->private_data = sysfs_new_dirent(parent_sd, NULL);
+ sd = sysfs_new_dirent("_DIR_", 0, 0);
+ if (sd)
+ sysfs_attach_dirent(sd, parent_sd, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
- return file->private_data ? 0 : -ENOMEM;
-
+ file->private_data = sd;
+ return sd ? 0 : -ENOMEM;
}
static int sysfs_dir_close(struct inode *inode, struct file *file)
switch (i) {
case 0:
- ino = dentry->d_inode->i_ino;
+ ino = parent_sd->s_ino;
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
break;
filp->f_pos++;
i++;
/* fallthrough */
case 1:
- ino = parent_ino(dentry);
+ if (parent_sd->s_parent)
+ ino = parent_sd->s_parent->s_ino;
+ else
+ ino = parent_sd->s_ino;
if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
break;
filp->f_pos++;
next = list_entry(p, struct sysfs_dirent,
s_sibling);
- if (!next->s_element)
+ if (!next->s_type)
continue;
- name = sysfs_get_name(next);
+ name = next->s_name;
len = strlen(name);
- if (next->s_dentry)
- ino = next->s_dentry->d_inode->i_ino;
- else
- ino = iunique(sysfs_sb, 2);
+ ino = next->s_ino;
if (filldir(dirent, name, len, filp->f_pos, ino,
dt_type(next)) < 0)
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;
}
struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
{
+ struct dentry *dir = kobj->dentry;
+ struct inode *inode = dir->d_inode;
+ struct dentry *parent = dir->d_parent;
+ struct sysfs_dirent *parent_sd = parent->d_fsdata;
+ struct dentry *shadow;
struct sysfs_dirent *sd;
- struct dentry *parent, *dir, *shadow;
- struct inode *inode;
- dir = kobj->dentry;
- inode = dir->d_inode;
- parent = dir->d_parent;
shadow = ERR_PTR(-EINVAL);
if (!sysfs_is_shadowed_inode(inode))
goto out;
if (!shadow)
goto nomem;
- sd = __sysfs_make_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);
d_instantiate(shadow, igrab(inode));
inc_nlink(inode);
projects / linux-2.6-omap-h63xx.git / blobdiff