/**
* sysfs_pathname - return full path to sysfs dirent
* @sd: sysfs_dirent whose path we want
- * @path: caller allocated buffer
+ * @path: caller allocated buffer of size PATH_MAX
*
* Gives the name "/" to the sysfs_root entry; any path returned
* is relative to wherever sysfs is mounted.
- *
- * XXX: does no error checking on @path size
*/
static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
{
if (sd->s_parent) {
sysfs_pathname(sd->s_parent, path);
- strcat(path, "/");
+ strlcat(path, "/", PATH_MAX);
}
- strcat(path, sd->s_name);
+ strlcat(path, sd->s_name, PATH_MAX);
return path;
}
char *path = kzalloc(PATH_MAX, GFP_KERNEL);
WARN(1, KERN_WARNING
"sysfs: cannot create duplicate filename '%s'\n",
- (path == NULL) ? sd->s_name :
- strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
- sd->s_name));
+ (path == NULL) ? sd->s_name
+ : (sysfs_pathname(acxt->parent_sd, path),
+ strlcat(path, "/", PATH_MAX),
+ strlcat(path, sd->s_name, PATH_MAX),
+ path));
kfree(path);
}
enum kobj_ns_type type;
const void *ns;
ino_t ino;
+ loff_t off;
type = sysfs_ns_type(parent_sd);
ns = sysfs_info(dentry->d_sb)->ns[type];
ino = parent_sd->s_ino;
if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
+ else
+ return 0;
}
if (filp->f_pos == 1) {
if (parent_sd->s_parent)
ino = parent_sd->s_ino;
if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
+ else
+ return 0;
}
mutex_lock(&sysfs_mutex);
+ off = filp->f_pos;
for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);
pos;
pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) {
len = strlen(name);
ino = pos->s_ino;
type = dt_type(pos);
- filp->f_pos = ino;
+ off = filp->f_pos = ino;
filp->private_data = sysfs_get(pos);
mutex_unlock(&sysfs_mutex);
- ret = filldir(dirent, name, len, filp->f_pos, ino, type);
+ ret = filldir(dirent, name, len, off, ino, type);
mutex_lock(&sysfs_mutex);
if (ret < 0)
break;
}
mutex_unlock(&sysfs_mutex);
- if ((filp->f_pos > 1) && !pos) { /* EOF */
- filp->f_pos = INT_MAX;
+
+ /* don't reference last entry if its refcount is dropped */
+ if (!pos) {
filp->private_data = NULL;
+
+ /* EOF and not changed as 0 or 1 in read/write path */
+ if (off == filp->f_pos && off > 1)
+ filp->f_pos = INT_MAX;
}
return 0;
}
+static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ loff_t ret;
+
+ mutex_lock(&inode->i_mutex);
+ ret = generic_file_llseek(file, offset, whence);
+ mutex_unlock(&inode->i_mutex);
+
+ return ret;
+}
const struct file_operations sysfs_dir_operations = {
.read = generic_read_dir,
.readdir = sysfs_readdir,
.release = sysfs_dir_release,
- .llseek = generic_file_llseek,
+ .llseek = sysfs_dir_llseek,
};