1042 lines
23 KiB
C
1042 lines
23 KiB
C
/*
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*
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* Copyright (C) 2011 Novell Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/namei.h>
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#include <linux/file.h>
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#include <linux/xattr.h>
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#include <linux/rbtree.h>
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#include <linux/security.h>
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#include <linux/cred.h>
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#include <linux/ratelimit.h>
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#include "overlayfs.h"
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struct ovl_cache_entry {
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unsigned int len;
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unsigned int type;
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u64 real_ino;
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u64 ino;
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struct list_head l_node;
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struct rb_node node;
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struct ovl_cache_entry *next_maybe_whiteout;
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bool is_whiteout;
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char name[];
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};
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struct ovl_dir_cache {
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long refcount;
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u64 version;
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struct list_head entries;
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struct rb_root root;
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};
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struct ovl_readdir_data {
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struct dir_context ctx;
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struct dentry *dentry;
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bool is_lowest;
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struct rb_root *root;
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struct list_head *list;
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struct list_head middle;
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struct ovl_cache_entry *first_maybe_whiteout;
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int count;
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int err;
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bool is_upper;
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bool d_type_supported;
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};
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struct ovl_dir_file {
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bool is_real;
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bool is_upper;
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struct ovl_dir_cache *cache;
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struct list_head *cursor;
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struct file *realfile;
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struct file *upperfile;
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};
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static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)
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{
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return rb_entry(n, struct ovl_cache_entry, node);
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}
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static bool ovl_cache_entry_find_link(const char *name, int len,
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struct rb_node ***link,
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struct rb_node **parent)
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{
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bool found = false;
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struct rb_node **newp = *link;
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while (!found && *newp) {
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int cmp;
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struct ovl_cache_entry *tmp;
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*parent = *newp;
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tmp = ovl_cache_entry_from_node(*newp);
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cmp = strncmp(name, tmp->name, len);
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if (cmp > 0)
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newp = &tmp->node.rb_right;
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else if (cmp < 0 || len < tmp->len)
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newp = &tmp->node.rb_left;
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else
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found = true;
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}
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*link = newp;
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return found;
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}
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static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
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const char *name, int len)
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{
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struct rb_node *node = root->rb_node;
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int cmp;
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while (node) {
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struct ovl_cache_entry *p = ovl_cache_entry_from_node(node);
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cmp = strncmp(name, p->name, len);
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if (cmp > 0)
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node = p->node.rb_right;
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else if (cmp < 0 || len < p->len)
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node = p->node.rb_left;
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else
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return p;
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}
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return NULL;
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}
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static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd,
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struct ovl_cache_entry *p)
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{
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/* Don't care if not doing ovl_iter() */
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if (!rdd->dentry)
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return false;
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/* Always recalc d_ino for parent */
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if (strcmp(p->name, "..") == 0)
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return true;
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/* If this is lower, then native d_ino will do */
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if (!rdd->is_upper)
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return false;
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/*
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* Recalc d_ino for '.' and for all entries if dir is impure (contains
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* copied up entries)
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*/
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if ((p->name[0] == '.' && p->len == 1) ||
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ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry)))
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return true;
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return false;
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}
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static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
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const char *name, int len,
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u64 ino, unsigned int d_type)
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{
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struct ovl_cache_entry *p;
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size_t size = offsetof(struct ovl_cache_entry, name[len + 1]);
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p = kmalloc(size, GFP_KERNEL);
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if (!p)
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return NULL;
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memcpy(p->name, name, len);
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p->name[len] = '\0';
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p->len = len;
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p->type = d_type;
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p->real_ino = ino;
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p->ino = ino;
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/* Defer setting d_ino for upper entry to ovl_iterate() */
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if (ovl_calc_d_ino(rdd, p))
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p->ino = 0;
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p->is_whiteout = false;
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if (d_type == DT_CHR) {
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p->next_maybe_whiteout = rdd->first_maybe_whiteout;
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rdd->first_maybe_whiteout = p;
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}
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return p;
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}
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static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
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const char *name, int len, u64 ino,
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unsigned int d_type)
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{
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struct rb_node **newp = &rdd->root->rb_node;
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struct rb_node *parent = NULL;
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struct ovl_cache_entry *p;
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if (ovl_cache_entry_find_link(name, len, &newp, &parent))
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return 0;
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p = ovl_cache_entry_new(rdd, name, len, ino, d_type);
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if (p == NULL) {
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rdd->err = -ENOMEM;
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return -ENOMEM;
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}
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list_add_tail(&p->l_node, rdd->list);
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rb_link_node(&p->node, parent, newp);
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rb_insert_color(&p->node, rdd->root);
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return 0;
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}
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static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
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const char *name, int namelen,
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loff_t offset, u64 ino, unsigned int d_type)
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{
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struct ovl_cache_entry *p;
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p = ovl_cache_entry_find(rdd->root, name, namelen);
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if (p) {
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list_move_tail(&p->l_node, &rdd->middle);
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} else {
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p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
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if (p == NULL)
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rdd->err = -ENOMEM;
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else
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list_add_tail(&p->l_node, &rdd->middle);
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}
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return rdd->err;
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}
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void ovl_cache_free(struct list_head *list)
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{
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struct ovl_cache_entry *p;
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struct ovl_cache_entry *n;
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list_for_each_entry_safe(p, n, list, l_node)
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kfree(p);
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INIT_LIST_HEAD(list);
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}
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void ovl_dir_cache_free(struct inode *inode)
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{
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struct ovl_dir_cache *cache = ovl_dir_cache(inode);
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if (cache) {
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ovl_cache_free(&cache->entries);
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kfree(cache);
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}
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}
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static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
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{
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struct ovl_dir_cache *cache = od->cache;
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WARN_ON(cache->refcount <= 0);
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cache->refcount--;
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if (!cache->refcount) {
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if (ovl_dir_cache(d_inode(dentry)) == cache)
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ovl_set_dir_cache(d_inode(dentry), NULL);
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ovl_cache_free(&cache->entries);
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kfree(cache);
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}
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}
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static int ovl_fill_merge(struct dir_context *ctx, const char *name,
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int namelen, loff_t offset, u64 ino,
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unsigned int d_type)
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{
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struct ovl_readdir_data *rdd =
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container_of(ctx, struct ovl_readdir_data, ctx);
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rdd->count++;
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if (!rdd->is_lowest)
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return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);
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else
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return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type);
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}
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static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
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{
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int err;
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struct ovl_cache_entry *p;
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struct dentry *dentry;
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const struct cred *old_cred;
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old_cred = ovl_override_creds(rdd->dentry->d_sb);
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err = down_write_killable(&dir->d_inode->i_rwsem);
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if (!err) {
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while (rdd->first_maybe_whiteout) {
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p = rdd->first_maybe_whiteout;
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rdd->first_maybe_whiteout = p->next_maybe_whiteout;
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dentry = lookup_one_len(p->name, dir, p->len);
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if (!IS_ERR(dentry)) {
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p->is_whiteout = ovl_is_whiteout(dentry);
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dput(dentry);
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}
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}
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inode_unlock(dir->d_inode);
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}
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revert_creds(old_cred);
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return err;
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}
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static inline int ovl_dir_read(struct path *realpath,
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struct ovl_readdir_data *rdd)
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{
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struct file *realfile;
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int err;
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realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY);
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if (IS_ERR(realfile))
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return PTR_ERR(realfile);
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rdd->first_maybe_whiteout = NULL;
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rdd->ctx.pos = 0;
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do {
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rdd->count = 0;
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rdd->err = 0;
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err = iterate_dir(realfile, &rdd->ctx);
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if (err >= 0)
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err = rdd->err;
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} while (!err && rdd->count);
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if (!err && rdd->first_maybe_whiteout && rdd->dentry)
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err = ovl_check_whiteouts(realpath->dentry, rdd);
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fput(realfile);
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return err;
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}
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static void ovl_dir_reset(struct file *file)
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{
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struct ovl_dir_file *od = file->private_data;
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struct ovl_dir_cache *cache = od->cache;
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struct dentry *dentry = file->f_path.dentry;
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enum ovl_path_type type = ovl_path_type(dentry);
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if (cache && ovl_dentry_version_get(dentry) != cache->version) {
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ovl_cache_put(od, dentry);
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od->cache = NULL;
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od->cursor = NULL;
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}
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WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type));
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if (od->is_real && OVL_TYPE_MERGE(type))
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od->is_real = false;
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}
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static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
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struct rb_root *root)
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{
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int err;
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struct path realpath;
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struct ovl_readdir_data rdd = {
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.ctx.actor = ovl_fill_merge,
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.dentry = dentry,
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.list = list,
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.root = root,
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.is_lowest = false,
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};
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int idx, next;
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for (idx = 0; idx != -1; idx = next) {
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next = ovl_path_next(idx, dentry, &realpath);
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rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry;
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if (next != -1) {
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err = ovl_dir_read(&realpath, &rdd);
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if (err)
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break;
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} else {
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/*
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* Insert lowest layer entries before upper ones, this
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* allows offsets to be reasonably constant
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*/
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list_add(&rdd.middle, rdd.list);
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rdd.is_lowest = true;
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err = ovl_dir_read(&realpath, &rdd);
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list_del(&rdd.middle);
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}
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}
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return err;
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}
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static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
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{
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struct list_head *p;
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loff_t off = 0;
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list_for_each(p, &od->cache->entries) {
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if (off >= pos)
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break;
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off++;
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}
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/* Cursor is safe since the cache is stable */
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od->cursor = p;
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}
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static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
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{
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int res;
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struct ovl_dir_cache *cache;
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cache = ovl_dir_cache(d_inode(dentry));
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if (cache && ovl_dentry_version_get(dentry) == cache->version) {
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WARN_ON(!cache->refcount);
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cache->refcount++;
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return cache;
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}
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ovl_set_dir_cache(d_inode(dentry), NULL);
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cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
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if (!cache)
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return ERR_PTR(-ENOMEM);
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cache->refcount = 1;
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INIT_LIST_HEAD(&cache->entries);
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cache->root = RB_ROOT;
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res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root);
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if (res) {
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ovl_cache_free(&cache->entries);
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kfree(cache);
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return ERR_PTR(res);
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}
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cache->version = ovl_dentry_version_get(dentry);
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ovl_set_dir_cache(d_inode(dentry), cache);
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return cache;
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}
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|
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/*
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* Set d_ino for upper entries. Non-upper entries should always report
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* the uppermost real inode ino and should not call this function.
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*
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* When not all layer are on same fs, report real ino also for upper.
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*
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* When all layers are on the same fs, and upper has a reference to
|
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* copy up origin, call vfs_getattr() on the overlay entry to make
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* sure that d_ino will be consistent with st_ino from stat(2).
|
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*/
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static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
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|
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{
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struct dentry *dir = path->dentry;
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struct dentry *this = NULL;
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enum ovl_path_type type;
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u64 ino = p->real_ino;
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int err = 0;
|
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|
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if (!ovl_same_sb(dir->d_sb))
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goto out;
|
|
|
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if (p->name[0] == '.') {
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if (p->len == 1) {
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this = dget(dir);
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goto get;
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}
|
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if (p->len == 2 && p->name[1] == '.') {
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/* we shall not be moved */
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this = dget(dir->d_parent);
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goto get;
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}
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}
|
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this = lookup_one_len(p->name, dir, p->len);
|
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if (IS_ERR_OR_NULL(this) || !this->d_inode) {
|
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if (IS_ERR(this)) {
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err = PTR_ERR(this);
|
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this = NULL;
|
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goto fail;
|
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}
|
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goto out;
|
|
}
|
|
|
|
get:
|
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type = ovl_path_type(this);
|
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if (OVL_TYPE_ORIGIN(type)) {
|
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struct kstat stat;
|
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struct path statpath = *path;
|
|
|
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statpath.dentry = this;
|
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err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
|
|
if (err)
|
|
goto fail;
|
|
|
|
WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
|
|
ino = stat.ino;
|
|
}
|
|
|
|
out:
|
|
p->ino = ino;
|
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dput(this);
|
|
return err;
|
|
|
|
fail:
|
|
pr_warn_ratelimited("overlay: failed to look up (%s) for ino (%i)\n",
|
|
p->name, err);
|
|
goto out;
|
|
}
|
|
|
|
static int ovl_fill_plain(struct dir_context *ctx, const char *name,
|
|
int namelen, loff_t offset, u64 ino,
|
|
unsigned int d_type)
|
|
{
|
|
struct ovl_cache_entry *p;
|
|
struct ovl_readdir_data *rdd =
|
|
container_of(ctx, struct ovl_readdir_data, ctx);
|
|
|
|
rdd->count++;
|
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p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
|
|
if (p == NULL) {
|
|
rdd->err = -ENOMEM;
|
|
return -ENOMEM;
|
|
}
|
|
list_add_tail(&p->l_node, rdd->list);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ovl_dir_read_impure(struct path *path, struct list_head *list,
|
|
struct rb_root *root)
|
|
{
|
|
int err;
|
|
struct path realpath;
|
|
struct ovl_cache_entry *p, *n;
|
|
struct ovl_readdir_data rdd = {
|
|
.ctx.actor = ovl_fill_plain,
|
|
.list = list,
|
|
.root = root,
|
|
};
|
|
|
|
INIT_LIST_HEAD(list);
|
|
*root = RB_ROOT;
|
|
ovl_path_upper(path->dentry, &realpath);
|
|
|
|
err = ovl_dir_read(&realpath, &rdd);
|
|
if (err)
|
|
return err;
|
|
|
|
list_for_each_entry_safe(p, n, list, l_node) {
|
|
if (strcmp(p->name, ".") != 0 &&
|
|
strcmp(p->name, "..") != 0) {
|
|
err = ovl_cache_update_ino(path, p);
|
|
if (err)
|
|
return err;
|
|
}
|
|
if (p->ino == p->real_ino) {
|
|
list_del(&p->l_node);
|
|
kfree(p);
|
|
} else {
|
|
struct rb_node **newp = &root->rb_node;
|
|
struct rb_node *parent = NULL;
|
|
|
|
if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len,
|
|
&newp, &parent)))
|
|
return -EIO;
|
|
|
|
rb_link_node(&p->node, parent, newp);
|
|
rb_insert_color(&p->node, root);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path)
|
|
{
|
|
int res;
|
|
struct dentry *dentry = path->dentry;
|
|
struct ovl_dir_cache *cache;
|
|
|
|
cache = ovl_dir_cache(d_inode(dentry));
|
|
if (cache && ovl_dentry_version_get(dentry) == cache->version)
|
|
return cache;
|
|
|
|
/* Impure cache is not refcounted, free it here */
|
|
ovl_dir_cache_free(d_inode(dentry));
|
|
ovl_set_dir_cache(d_inode(dentry), NULL);
|
|
|
|
cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
|
|
if (!cache)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
res = ovl_dir_read_impure(path, &cache->entries, &cache->root);
|
|
if (res) {
|
|
ovl_cache_free(&cache->entries);
|
|
kfree(cache);
|
|
return ERR_PTR(res);
|
|
}
|
|
if (list_empty(&cache->entries)) {
|
|
/* Good oportunity to get rid of an unnecessary "impure" flag */
|
|
ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE);
|
|
ovl_clear_flag(OVL_IMPURE, d_inode(dentry));
|
|
kfree(cache);
|
|
return NULL;
|
|
}
|
|
|
|
cache->version = ovl_dentry_version_get(dentry);
|
|
ovl_set_dir_cache(d_inode(dentry), cache);
|
|
|
|
return cache;
|
|
}
|
|
|
|
struct ovl_readdir_translate {
|
|
struct dir_context *orig_ctx;
|
|
struct ovl_dir_cache *cache;
|
|
struct dir_context ctx;
|
|
u64 parent_ino;
|
|
};
|
|
|
|
static int ovl_fill_real(struct dir_context *ctx, const char *name,
|
|
int namelen, loff_t offset, u64 ino,
|
|
unsigned int d_type)
|
|
{
|
|
struct ovl_readdir_translate *rdt =
|
|
container_of(ctx, struct ovl_readdir_translate, ctx);
|
|
struct dir_context *orig_ctx = rdt->orig_ctx;
|
|
|
|
if (rdt->parent_ino && strcmp(name, "..") == 0)
|
|
ino = rdt->parent_ino;
|
|
else if (rdt->cache) {
|
|
struct ovl_cache_entry *p;
|
|
|
|
p = ovl_cache_entry_find(&rdt->cache->root, name, namelen);
|
|
if (p)
|
|
ino = p->ino;
|
|
}
|
|
|
|
return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
|
|
}
|
|
|
|
static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
|
|
{
|
|
int err;
|
|
struct ovl_dir_file *od = file->private_data;
|
|
struct dentry *dir = file->f_path.dentry;
|
|
struct ovl_readdir_translate rdt = {
|
|
.ctx.actor = ovl_fill_real,
|
|
.orig_ctx = ctx,
|
|
};
|
|
|
|
if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) {
|
|
struct kstat stat;
|
|
struct path statpath = file->f_path;
|
|
|
|
statpath.dentry = dir->d_parent;
|
|
err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
|
|
if (err)
|
|
return err;
|
|
|
|
WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
|
|
rdt.parent_ino = stat.ino;
|
|
}
|
|
|
|
if (ovl_test_flag(OVL_IMPURE, d_inode(dir))) {
|
|
rdt.cache = ovl_cache_get_impure(&file->f_path);
|
|
if (IS_ERR(rdt.cache))
|
|
return PTR_ERR(rdt.cache);
|
|
}
|
|
|
|
return iterate_dir(od->realfile, &rdt.ctx);
|
|
}
|
|
|
|
|
|
static int ovl_iterate(struct file *file, struct dir_context *ctx)
|
|
{
|
|
struct ovl_dir_file *od = file->private_data;
|
|
struct dentry *dentry = file->f_path.dentry;
|
|
struct ovl_cache_entry *p;
|
|
int err;
|
|
|
|
if (!ctx->pos)
|
|
ovl_dir_reset(file);
|
|
|
|
if (od->is_real) {
|
|
/*
|
|
* If parent is merge, then need to adjust d_ino for '..', if
|
|
* dir is impure then need to adjust d_ino for copied up
|
|
* entries.
|
|
*/
|
|
if (ovl_same_sb(dentry->d_sb) &&
|
|
(ovl_test_flag(OVL_IMPURE, d_inode(dentry)) ||
|
|
OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) {
|
|
return ovl_iterate_real(file, ctx);
|
|
}
|
|
return iterate_dir(od->realfile, ctx);
|
|
}
|
|
|
|
if (!od->cache) {
|
|
struct ovl_dir_cache *cache;
|
|
|
|
cache = ovl_cache_get(dentry);
|
|
if (IS_ERR(cache))
|
|
return PTR_ERR(cache);
|
|
|
|
od->cache = cache;
|
|
ovl_seek_cursor(od, ctx->pos);
|
|
}
|
|
|
|
while (od->cursor != &od->cache->entries) {
|
|
p = list_entry(od->cursor, struct ovl_cache_entry, l_node);
|
|
if (!p->is_whiteout) {
|
|
if (!p->ino) {
|
|
err = ovl_cache_update_ino(&file->f_path, p);
|
|
if (err)
|
|
return err;
|
|
}
|
|
if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
|
|
break;
|
|
}
|
|
od->cursor = p->l_node.next;
|
|
ctx->pos++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
|
|
{
|
|
loff_t res;
|
|
struct ovl_dir_file *od = file->private_data;
|
|
|
|
inode_lock(file_inode(file));
|
|
if (!file->f_pos)
|
|
ovl_dir_reset(file);
|
|
|
|
if (od->is_real) {
|
|
res = vfs_llseek(od->realfile, offset, origin);
|
|
file->f_pos = od->realfile->f_pos;
|
|
} else {
|
|
res = -EINVAL;
|
|
|
|
switch (origin) {
|
|
case SEEK_CUR:
|
|
offset += file->f_pos;
|
|
break;
|
|
case SEEK_SET:
|
|
break;
|
|
default:
|
|
goto out_unlock;
|
|
}
|
|
if (offset < 0)
|
|
goto out_unlock;
|
|
|
|
if (offset != file->f_pos) {
|
|
file->f_pos = offset;
|
|
if (od->cache)
|
|
ovl_seek_cursor(od, offset);
|
|
}
|
|
res = offset;
|
|
}
|
|
out_unlock:
|
|
inode_unlock(file_inode(file));
|
|
|
|
return res;
|
|
}
|
|
|
|
static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
|
|
int datasync)
|
|
{
|
|
struct ovl_dir_file *od = file->private_data;
|
|
struct dentry *dentry = file->f_path.dentry;
|
|
struct file *realfile = od->realfile;
|
|
|
|
/*
|
|
* Need to check if we started out being a lower dir, but got copied up
|
|
*/
|
|
if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) {
|
|
struct inode *inode = file_inode(file);
|
|
|
|
realfile = lockless_dereference(od->upperfile);
|
|
if (!realfile) {
|
|
struct path upperpath;
|
|
|
|
ovl_path_upper(dentry, &upperpath);
|
|
realfile = ovl_path_open(&upperpath, O_RDONLY);
|
|
|
|
inode_lock(inode);
|
|
if (!od->upperfile) {
|
|
if (IS_ERR(realfile)) {
|
|
inode_unlock(inode);
|
|
return PTR_ERR(realfile);
|
|
}
|
|
smp_store_release(&od->upperfile, realfile);
|
|
} else {
|
|
/* somebody has beaten us to it */
|
|
if (!IS_ERR(realfile))
|
|
fput(realfile);
|
|
realfile = od->upperfile;
|
|
}
|
|
inode_unlock(inode);
|
|
}
|
|
}
|
|
|
|
return vfs_fsync_range(realfile, start, end, datasync);
|
|
}
|
|
|
|
static int ovl_dir_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct ovl_dir_file *od = file->private_data;
|
|
|
|
if (od->cache) {
|
|
inode_lock(inode);
|
|
ovl_cache_put(od, file->f_path.dentry);
|
|
inode_unlock(inode);
|
|
}
|
|
fput(od->realfile);
|
|
if (od->upperfile)
|
|
fput(od->upperfile);
|
|
kfree(od);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ovl_dir_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct path realpath;
|
|
struct file *realfile;
|
|
struct ovl_dir_file *od;
|
|
enum ovl_path_type type;
|
|
|
|
od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL);
|
|
if (!od)
|
|
return -ENOMEM;
|
|
|
|
type = ovl_path_real(file->f_path.dentry, &realpath);
|
|
realfile = ovl_path_open(&realpath, file->f_flags);
|
|
if (IS_ERR(realfile)) {
|
|
kfree(od);
|
|
return PTR_ERR(realfile);
|
|
}
|
|
od->realfile = realfile;
|
|
od->is_real = !OVL_TYPE_MERGE(type);
|
|
od->is_upper = OVL_TYPE_UPPER(type);
|
|
file->private_data = od;
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct file_operations ovl_dir_operations = {
|
|
.read = generic_read_dir,
|
|
.open = ovl_dir_open,
|
|
.iterate = ovl_iterate,
|
|
.llseek = ovl_dir_llseek,
|
|
.fsync = ovl_dir_fsync,
|
|
.release = ovl_dir_release,
|
|
};
|
|
|
|
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
|
|
{
|
|
int err;
|
|
struct ovl_cache_entry *p;
|
|
struct rb_root root = RB_ROOT;
|
|
|
|
err = ovl_dir_read_merged(dentry, list, &root);
|
|
if (err)
|
|
return err;
|
|
|
|
err = 0;
|
|
|
|
list_for_each_entry(p, list, l_node) {
|
|
if (p->is_whiteout)
|
|
continue;
|
|
|
|
if (p->name[0] == '.') {
|
|
if (p->len == 1)
|
|
continue;
|
|
if (p->len == 2 && p->name[1] == '.')
|
|
continue;
|
|
}
|
|
err = -ENOTEMPTY;
|
|
break;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
|
|
{
|
|
struct ovl_cache_entry *p;
|
|
|
|
inode_lock_nested(upper->d_inode, I_MUTEX_CHILD);
|
|
list_for_each_entry(p, list, l_node) {
|
|
struct dentry *dentry;
|
|
|
|
if (!p->is_whiteout)
|
|
continue;
|
|
|
|
dentry = lookup_one_len(p->name, upper, p->len);
|
|
if (IS_ERR(dentry)) {
|
|
pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n",
|
|
upper->d_name.name, p->len, p->name,
|
|
(int) PTR_ERR(dentry));
|
|
continue;
|
|
}
|
|
if (dentry->d_inode)
|
|
ovl_cleanup(upper->d_inode, dentry);
|
|
dput(dentry);
|
|
}
|
|
inode_unlock(upper->d_inode);
|
|
}
|
|
|
|
static int ovl_check_d_type(struct dir_context *ctx, const char *name,
|
|
int namelen, loff_t offset, u64 ino,
|
|
unsigned int d_type)
|
|
{
|
|
struct ovl_readdir_data *rdd =
|
|
container_of(ctx, struct ovl_readdir_data, ctx);
|
|
|
|
/* Even if d_type is not supported, DT_DIR is returned for . and .. */
|
|
if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen))
|
|
return 0;
|
|
|
|
if (d_type != DT_UNKNOWN)
|
|
rdd->d_type_supported = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Returns 1 if d_type is supported, 0 not supported/unknown. Negative values
|
|
* if error is encountered.
|
|
*/
|
|
int ovl_check_d_type_supported(struct path *realpath)
|
|
{
|
|
int err;
|
|
struct ovl_readdir_data rdd = {
|
|
.ctx.actor = ovl_check_d_type,
|
|
.d_type_supported = false,
|
|
};
|
|
|
|
err = ovl_dir_read(realpath, &rdd);
|
|
if (err)
|
|
return err;
|
|
|
|
return rdd.d_type_supported;
|
|
}
|
|
|
|
static void ovl_workdir_cleanup_recurse(struct path *path, int level)
|
|
{
|
|
int err;
|
|
struct inode *dir = path->dentry->d_inode;
|
|
LIST_HEAD(list);
|
|
struct rb_root root = RB_ROOT;
|
|
struct ovl_cache_entry *p;
|
|
struct ovl_readdir_data rdd = {
|
|
.ctx.actor = ovl_fill_merge,
|
|
.dentry = NULL,
|
|
.list = &list,
|
|
.root = &root,
|
|
.is_lowest = false,
|
|
};
|
|
|
|
err = ovl_dir_read(path, &rdd);
|
|
if (err)
|
|
goto out;
|
|
|
|
inode_lock_nested(dir, I_MUTEX_PARENT);
|
|
list_for_each_entry(p, &list, l_node) {
|
|
struct dentry *dentry;
|
|
|
|
if (p->name[0] == '.') {
|
|
if (p->len == 1)
|
|
continue;
|
|
if (p->len == 2 && p->name[1] == '.')
|
|
continue;
|
|
}
|
|
dentry = lookup_one_len(p->name, path->dentry, p->len);
|
|
if (IS_ERR(dentry))
|
|
continue;
|
|
if (dentry->d_inode)
|
|
ovl_workdir_cleanup(dir, path->mnt, dentry, level);
|
|
dput(dentry);
|
|
}
|
|
inode_unlock(dir);
|
|
out:
|
|
ovl_cache_free(&list);
|
|
}
|
|
|
|
void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
|
|
struct dentry *dentry, int level)
|
|
{
|
|
int err;
|
|
|
|
if (!d_is_dir(dentry) || level > 1) {
|
|
ovl_cleanup(dir, dentry);
|
|
return;
|
|
}
|
|
|
|
err = ovl_do_rmdir(dir, dentry);
|
|
if (err) {
|
|
struct path path = { .mnt = mnt, .dentry = dentry };
|
|
|
|
inode_unlock(dir);
|
|
ovl_workdir_cleanup_recurse(&path, level + 1);
|
|
inode_lock_nested(dir, I_MUTEX_PARENT);
|
|
ovl_cleanup(dir, dentry);
|
|
}
|
|
}
|
|
|
|
int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
|
|
struct path *lowerstack, unsigned int numlower)
|
|
{
|
|
int err;
|
|
struct dentry *index = NULL;
|
|
struct inode *dir = dentry->d_inode;
|
|
struct path path = { .mnt = mnt, .dentry = dentry };
|
|
LIST_HEAD(list);
|
|
struct rb_root root = RB_ROOT;
|
|
struct ovl_cache_entry *p;
|
|
struct ovl_readdir_data rdd = {
|
|
.ctx.actor = ovl_fill_merge,
|
|
.dentry = NULL,
|
|
.list = &list,
|
|
.root = &root,
|
|
.is_lowest = false,
|
|
};
|
|
|
|
err = ovl_dir_read(&path, &rdd);
|
|
if (err)
|
|
goto out;
|
|
|
|
inode_lock_nested(dir, I_MUTEX_PARENT);
|
|
list_for_each_entry(p, &list, l_node) {
|
|
if (p->name[0] == '.') {
|
|
if (p->len == 1)
|
|
continue;
|
|
if (p->len == 2 && p->name[1] == '.')
|
|
continue;
|
|
}
|
|
index = lookup_one_len(p->name, dentry, p->len);
|
|
if (IS_ERR(index)) {
|
|
err = PTR_ERR(index);
|
|
index = NULL;
|
|
break;
|
|
}
|
|
err = ovl_verify_index(index, lowerstack, numlower);
|
|
if (err) {
|
|
if (err == -EROFS)
|
|
break;
|
|
err = ovl_cleanup(dir, index);
|
|
if (err)
|
|
break;
|
|
}
|
|
dput(index);
|
|
index = NULL;
|
|
}
|
|
dput(index);
|
|
inode_unlock(dir);
|
|
out:
|
|
ovl_cache_free(&list);
|
|
if (err)
|
|
pr_err("overlayfs: failed index dir cleanup (%i)\n", err);
|
|
return err;
|
|
}
|