return sd;
}
+/*
+ *
+ * Return -EEXIST if there is already a configfs element with the same
+ * name for the same parent.
+ *
+ * called with parent inode's i_mutex held
+ */
+static int configfs_dirent_exists(struct configfs_dirent *parent_sd,
+ const unsigned char *new)
+{
+ struct configfs_dirent * sd;
+
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (sd->s_element) {
+ const unsigned char *existing = configfs_get_name(sd);
+ if (strcmp(existing, new))
+ continue;
+ else
+ return -EEXIST;
+ }
+ }
+
+ return 0;
+}
+
+
int configfs_make_dirent(struct configfs_dirent * parent_sd,
struct dentry * dentry, void * element,
umode_t mode, int type)
inode->i_fop = &configfs_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
- inode->i_nlink++;
+ inc_nlink(inode);
return 0;
}
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
- error = configfs_make_dirent(p->d_fsdata, d, k, mode,
- CONFIGFS_DIR);
+ error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
+ if (!error)
+ error = configfs_make_dirent(p->d_fsdata, d, k, mode,
+ CONFIGFS_DIR);
if (!error) {
error = configfs_create(d, mode, init_dir);
if (!error) {
- p->d_inode->i_nlink++;
+ inc_nlink(p->d_inode);
(d)->d_op = &configfs_dentry_ops;
} else {
struct configfs_dirent *sd = d->d_fsdata;
struct configfs_dirent * sd;
sd = d->d_fsdata;
- list_del_init(&sd->s_sibling);
+ list_del_init(&sd->s_sibling);
configfs_put(sd);
if (d->d_inode)
simple_rmdir(parent->d_inode,d);
ret = configfs_detach_prep(sd->s_dentry);
if (!ret)
- continue;
+ continue;
} else
ret = -ENOTEMPTY;
int ret = 0;
int i;
- if (group && group->default_groups) {
- /* FYI, we're faking mkdir here
+ if (group->default_groups) {
+ /*
+ * FYI, we're faking mkdir here
* I'm not sure we need this semaphore, as we're called
* from our parent's mkdir. That holds our parent's
* i_mutex, so afaik lookup cannot continue through our
* parent to find us, let alone mess with our tree.
* That said, taking our i_mutex is closer to mkdir
- * emulation, and shouldn't hurt. */
+ * emulation, and shouldn't hurt.
+ */
mutex_lock(&dentry->d_inode->i_mutex);
for (i = 0; group->default_groups[i]; i++) {
item->ci_group = NULL;
item->ci_parent = NULL;
+
+ /* Drop the reference for ci_entry */
config_item_put(item);
+ /* Drop the reference for ci_parent */
config_group_put(group);
}
}
static void link_obj(struct config_item *parent_item, struct config_item *item)
{
- /* Parent seems redundant with group, but it makes certain
- * traversals much nicer. */
+ /*
+ * Parent seems redundant with group, but it makes certain
+ * traversals much nicer.
+ */
item->ci_parent = parent_item;
+
+ /*
+ * We hold a reference on the parent for the child's ci_parent
+ * link.
+ */
item->ci_group = config_group_get(to_config_group(parent_item));
list_add_tail(&item->ci_entry, &item->ci_group->cg_children);
+ /*
+ * We hold a reference on the child for ci_entry on the parent's
+ * cg_children
+ */
config_item_get(item);
}
type = parent_item->ci_type;
BUG_ON(!type);
+ /*
+ * If ->drop_item() exists, it is responsible for the
+ * config_item_put().
+ */
if (type->ct_group_ops && type->ct_group_ops->drop_item)
type->ct_group_ops->drop_item(to_config_group(parent_item),
item);
static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
- int ret;
+ int ret, module_got = 0;
struct config_group *group;
struct config_item *item;
struct config_item *parent_item;
struct configfs_subsystem *subsys;
struct configfs_dirent *sd;
struct config_item_type *type;
- struct module *owner;
+ struct module *owner = NULL;
char *name;
- if (dentry->d_parent == configfs_sb->s_root)
- return -EPERM;
+ if (dentry->d_parent == configfs_sb->s_root) {
+ ret = -EPERM;
+ goto out;
+ }
sd = dentry->d_parent->d_fsdata;
- if (!(sd->s_type & CONFIGFS_USET_DIR))
- return -EPERM;
+ if (!(sd->s_type & CONFIGFS_USET_DIR)) {
+ ret = -EPERM;
+ goto out;
+ }
+ /* Get a working ref for the duration of this function */
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
subsys = to_config_group(parent_item)->cg_subsys;
if (!type || !type->ct_group_ops ||
(!type->ct_group_ops->make_group &&
!type->ct_group_ops->make_item)) {
- config_item_put(parent_item);
- return -EPERM; /* What lack-of-mkdir returns */
+ ret = -EPERM; /* Lack-of-mkdir returns -EPERM */
+ goto out_put;
}
name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
if (!name) {
- config_item_put(parent_item);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto out_put;
}
+
snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
down(&subsys->su_sem);
kfree(name);
if (!item) {
- config_item_put(parent_item);
- return -ENOMEM;
+ /*
+ * If item == NULL, then link_obj() was never called.
+ * There are no extra references to clean up.
+ */
+ ret = -ENOMEM;
+ goto out_put;
}
- ret = -EINVAL;
+ /*
+ * link_obj() has been called (via link_group() for groups).
+ * From here on out, errors must clean that up.
+ */
+
type = item->ci_type;
- if (type) {
- owner = type->ct_owner;
- if (try_module_get(owner)) {
- if (group) {
- ret = configfs_attach_group(parent_item,
- item,
- dentry);
- } else {
- ret = configfs_attach_item(parent_item,
- item,
- dentry);
- }
+ if (!type) {
+ ret = -EINVAL;
+ goto out_unlink;
+ }
- if (ret) {
- down(&subsys->su_sem);
- if (group)
- unlink_group(group);
- else
- unlink_obj(item);
- client_drop_item(parent_item, item);
- up(&subsys->su_sem);
+ owner = type->ct_owner;
+ if (!try_module_get(owner)) {
+ ret = -EINVAL;
+ goto out_unlink;
+ }
- config_item_put(parent_item);
- module_put(owner);
- }
- }
+ /*
+ * I hate doing it this way, but if there is
+ * an error, module_put() probably should
+ * happen after any cleanup.
+ */
+ module_got = 1;
+
+ if (group)
+ ret = configfs_attach_group(parent_item, item, dentry);
+ else
+ ret = configfs_attach_item(parent_item, item, dentry);
+
+out_unlink:
+ if (ret) {
+ /* Tear down everything we built up */
+ down(&subsys->su_sem);
+ if (group)
+ unlink_group(group);
+ else
+ unlink_obj(item);
+ client_drop_item(parent_item, item);
+ up(&subsys->su_sem);
+
+ if (module_got)
+ module_put(owner);
}
+out_put:
+ /*
+ * link_obj()/link_group() took a reference from child->parent,
+ * so the parent is safely pinned. We can drop our working
+ * reference.
+ */
+ config_item_put(parent_item);
+
+out:
return ret;
}
if (sd->s_type & CONFIGFS_USET_DEFAULT)
return -EPERM;
+ /* Get a working ref until we have the child */
parent_item = configfs_get_config_item(dentry->d_parent);
subsys = to_config_group(parent_item)->cg_subsys;
BUG_ON(!subsys);
return ret;
}
+ /* Get a working ref for the duration of this function */
item = configfs_get_config_item(dentry);
/* Drop reference from above, item already holds one. */
new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
if (!IS_ERR(new_dentry)) {
- if (!new_dentry->d_inode) {
+ if (!new_dentry->d_inode) {
error = config_item_set_name(item, "%s", new_name);
if (!error) {
d_add(new_dentry, NULL);
static int configfs_dir_open(struct inode *inode, struct file *file)
{
- struct dentry * dentry = file->f_dentry;
+ struct dentry * dentry = file->f_path.dentry;
struct configfs_dirent * parent_sd = dentry->d_fsdata;
mutex_lock(&dentry->d_inode->i_mutex);
static int configfs_dir_close(struct inode *inode, struct file *file)
{
- struct dentry * dentry = file->f_dentry;
+ struct dentry * dentry = file->f_path.dentry;
struct configfs_dirent * cursor = file->private_data;
mutex_lock(&dentry->d_inode->i_mutex);
static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
- struct dentry *dentry = filp->f_dentry;
+ struct dentry *dentry = filp->f_path.dentry;
struct configfs_dirent * parent_sd = dentry->d_fsdata;
struct configfs_dirent *cursor = filp->private_data;
struct list_head *p, *q = &cursor->s_sibling;
/* fallthrough */
default:
if (filp->f_pos == 2) {
- list_del(q);
- list_add(q, &parent_sd->s_children);
+ list_move(q, &parent_sd->s_children);
}
for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
struct configfs_dirent *next;
dt_type(next)) < 0)
return 0;
- list_del(q);
- list_add(q, p);
+ list_move(q, p);
p = q;
filp->f_pos++;
}
static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin)
{
- struct dentry * dentry = file->f_dentry;
+ struct dentry * dentry = file->f_path.dentry;
mutex_lock(&dentry->d_inode->i_mutex);
switch (origin) {
if (offset >= 0)
break;
default:
- mutex_unlock(&file->f_dentry->d_inode->i_mutex);
+ mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
return offset;
}
-struct file_operations configfs_dir_operations = {
+const struct file_operations configfs_dir_operations = {
.open = configfs_dir_open,
.release = configfs_dir_close,
.llseek = configfs_dir_lseek,
return;
}
- mutex_lock(&configfs_sb->s_root->d_inode->i_mutex);
- mutex_lock(&dentry->d_inode->i_mutex);
+ mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
+ I_MUTEX_PARENT);
+ mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
if (configfs_detach_prep(dentry)) {
printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
}
git://git.onelab.eu / linux-2.6.git / blobdiff