static int dev_rmdir(const char *name)
{
struct nameidata nd;
struct dentry *dentry;
int err;
err = kern_path_parent(name, &nd);
if (err)
return err;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
if (dentry->d_inode) {
if (dentry->d_inode->i_private == &thread)
err = vfs_rmdir(nd.path.dentry->d_inode,
dentry);
else
err = -EPERM;
} else {
err = -ENOENT;
}
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}
static int handle_remove(const char *nodename, struct device *dev)
{
struct nameidata nd;
struct dentry *dentry;
struct kstat stat;
int deleted = 1;
int err;
err = kern_path_parent(nodename, &nd);
if (err)
return err;
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
if (dentry->d_inode) {
err = vfs_getattr(nd.path.mnt, dentry, &stat);
if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
struct iattr newattrs;
/*
* before unlinking this node, reset permissions
* of possible references like hardlinks
*/
newattrs.ia_uid = 0;
newattrs.ia_gid = 0;
newattrs.ia_mode = stat.mode & ~0777;
newattrs.ia_valid =
ATTR_UID|ATTR_GID|ATTR_MODE;
mutex_lock(&dentry->d_inode->i_mutex);
notify_change(dentry, &newattrs);
mutex_unlock(&dentry->d_inode->i_mutex);
err = vfs_unlink(nd.path.dentry->d_inode,
dentry);
if (!err || err == -ENOENT)
deleted = 1;
}
} else {
err = -ENOENT;
}
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
return err;
}
int file_mkdir(const char * pathname, unsigned short perms, int recurse) {
/* Welcome to the jungle... */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,41)
/* DO NOT REFERENCE THIS VARIABLE */
/* It only exists to provide version compatibility */
struct path tmp_path;
#endif
struct path * path_ptr = NULL;
struct dentry * dentry;
int ret = 0;
if (recurse != 0) {
return mkdir_recursive(pathname, perms);
}
/* Before Linux 3.1 this was somewhat more difficult */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,41)
{
struct nameidata nd;
// I'm not 100% sure about the version here, but it was around this time that the API changed
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,38)
ret = kern_path_parent(pathname, &nd);
#else
if (path_lookup(pathname, LOOKUP_DIRECTORY | LOOKUP_FOLLOW, &nd) == 0) {
return 0;
}
if (path_lookup(pathname, LOOKUP_PARENT | LOOKUP_FOLLOW, &nd) != 0) {
return -1;
}
#endif
if (ret != 0) {
printk(KERN_ERR "%s:%d - Error: kern_path_parent() returned error for (%s)\n", __FILE__, __LINE__,
pathname);
return -1;
}
dentry = lookup_create(&nd, 1);
path_ptr = &(nd.path);
}
#else
{
dentry = kern_path_create(AT_FDCWD, pathname, &tmp_path, 1);
if (IS_ERR(dentry)) {
return 0;
}
path_ptr = &tmp_path;
}
#endif
if (!IS_ERR(dentry)) {
ret = vfs_mkdir(path_ptr->dentry->d_inode, dentry, perms);
}
mutex_unlock(&(path_ptr->dentry->d_inode->i_mutex));
path_put(path_ptr);
return ret;
}
/*
* Safely creates '/proc/systemtap' (if necessary) and
* '/proc/systemtap/{module_name}'.
*
* NB: this function is suitable to call from early in the the
* module-init function, and doesn't rely on any other facilities
* in our runtime. PR19833. See also PR15408.
*/
static int _stp_mkdir_proc_module(void)
{
int found = 0;
static char proc_root_name[STP_MODULE_NAME_LEN + sizeof("systemtap/")];
#if defined(STAPCONF_PATH_LOOKUP) || defined(STAPCONF_KERN_PATH_PARENT)
struct nameidata nd;
#else /* STAPCONF_VFS_PATH_LOOKUP or STAPCONF_KERN_PATH */
struct path path;
#if defined(STAPCONF_VFS_PATH_LOOKUP)
struct vfsmount *mnt;
#endif
int rc;
#endif /* STAPCONF_VFS_PATH_LOOKUP or STAPCONF_KERN_PATH */
if (_stp_proc_root != NULL)
return 0;
#if defined(STAPCONF_PATH_LOOKUP) || defined(STAPCONF_KERN_PATH_PARENT)
/* Why "/proc/systemtap/foo"? kern_path_parent() is basically
* the same thing as calling the old path_lookup() with flags
* set to LOOKUP_PARENT, which means to look up the parent of
* the path, which in this case is "/proc/systemtap". */
if (! kern_path_parent("/proc/systemtap/foo", &nd)) {
found = 1;
#ifdef STAPCONF_NAMEIDATA_CLEANUP
path_put(&nd.path);
#else /* !STAPCONF_NAMEIDATA_CLEANUP */
path_release(&nd);
#endif /* !STAPCONF_NAMEIDATA_CLEANUP */
}
#elif defined(STAPCONF_KERN_PATH)
/* Prefer kern_path() over vfs_path_lookup(), since on some
* kernels the declaration for vfs_path_lookup() was moved to
* a private header. */
/* See if '/proc/systemtap' exists. */
rc = kern_path("/proc/systemtap", 0, &path);
if (rc == 0) {
found = 1;
path_put (&path);
}
#else /* STAPCONF_VFS_PATH_LOOKUP */
/* See if '/proc/systemtap' exists. */
if (! init_pid_ns.proc_mnt) {
errk("Unable to create '/proc/systemap':"
" '/proc' doesn't exist.\n");
goto done;
}
mnt = init_pid_ns.proc_mnt;
rc = vfs_path_lookup(mnt->mnt_root, mnt, "systemtap", 0, &path);
if (rc == 0) {
found = 1;
path_put (&path);
}
#endif /* STAPCONF_VFS_PATH_LOOKUP */
/* If we couldn't find "/proc/systemtap", create it. */
if (!found) {
struct proc_dir_entry *de;
de = proc_mkdir ("systemtap", NULL);
if (de == NULL) {
errk("Unable to create '/proc/systemap':"
" proc_mkdir failed.\n");
goto done;
}
}
/* Create the "systemtap/{module_name} directory in procfs. */
strlcpy(proc_root_name, "systemtap/", sizeof(proc_root_name));
strlcat(proc_root_name, THIS_MODULE->name, sizeof(proc_root_name));
_stp_proc_root = proc_mkdir(proc_root_name, NULL);
#ifdef STAPCONF_PROCFS_OWNER
if (_stp_proc_root != NULL)
_stp_proc_root->owner = THIS_MODULE;
#endif
if (_stp_proc_root == NULL)
errk("Unable to create '/proc/systemap/%s':"
" proc_mkdir failed.\n", THIS_MODULE->name);
done:
return (_stp_proc_root) ? 0 : -EINVAL;
}
