Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 1 | /* |
| 2 | * |
| 3 | * Copyright (C) 2011 Novell Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 as published by |
| 7 | * the Free Software Foundation. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/namei.h> |
| 13 | #include <linux/file.h> |
| 14 | #include <linux/xattr.h> |
| 15 | #include <linux/rbtree.h> |
| 16 | #include <linux/security.h> |
| 17 | #include <linux/cred.h> |
| 18 | #include "overlayfs.h" |
| 19 | |
| 20 | struct ovl_cache_entry { |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 21 | unsigned int len; |
| 22 | unsigned int type; |
| 23 | u64 ino; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 24 | struct list_head l_node; |
| 25 | struct rb_node node; |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 26 | struct ovl_cache_entry *next_maybe_whiteout; |
Miklos Szeredi | c209653 | 2014-10-27 13:48:48 +0100 | [diff] [blame] | 27 | bool is_whiteout; |
Al Viro | 68bf861 | 2014-10-23 22:58:56 -0400 | [diff] [blame] | 28 | char name[]; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 29 | }; |
| 30 | |
| 31 | struct ovl_dir_cache { |
| 32 | long refcount; |
| 33 | u64 version; |
| 34 | struct list_head entries; |
| 35 | }; |
| 36 | |
| 37 | struct ovl_readdir_data { |
| 38 | struct dir_context ctx; |
Antonio Murdaca | 3fe6e52 | 2016-04-07 15:48:25 +0200 | [diff] [blame] | 39 | struct dentry *dentry; |
Miklos Szeredi | 56656e9 | 2016-03-21 17:31:46 +0100 | [diff] [blame] | 40 | bool is_lowest; |
Al Viro | 49be4fb | 2014-10-23 23:00:53 -0400 | [diff] [blame] | 41 | struct rb_root root; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 42 | struct list_head *list; |
Al Viro | db6ec21 | 2014-10-23 23:03:03 -0400 | [diff] [blame] | 43 | struct list_head middle; |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 44 | struct ovl_cache_entry *first_maybe_whiteout; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 45 | int count; |
| 46 | int err; |
Vivek Goyal | 45aebea | 2016-02-22 09:28:34 -0500 | [diff] [blame] | 47 | bool d_type_supported; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 48 | }; |
| 49 | |
| 50 | struct ovl_dir_file { |
| 51 | bool is_real; |
| 52 | bool is_upper; |
| 53 | struct ovl_dir_cache *cache; |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 54 | struct list_head *cursor; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 55 | struct file *realfile; |
| 56 | struct file *upperfile; |
| 57 | }; |
| 58 | |
| 59 | static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n) |
| 60 | { |
| 61 | return container_of(n, struct ovl_cache_entry, node); |
| 62 | } |
| 63 | |
| 64 | static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, |
| 65 | const char *name, int len) |
| 66 | { |
| 67 | struct rb_node *node = root->rb_node; |
| 68 | int cmp; |
| 69 | |
| 70 | while (node) { |
| 71 | struct ovl_cache_entry *p = ovl_cache_entry_from_node(node); |
| 72 | |
| 73 | cmp = strncmp(name, p->name, len); |
| 74 | if (cmp > 0) |
| 75 | node = p->node.rb_right; |
| 76 | else if (cmp < 0 || len < p->len) |
| 77 | node = p->node.rb_left; |
| 78 | else |
| 79 | return p; |
| 80 | } |
| 81 | |
| 82 | return NULL; |
| 83 | } |
| 84 | |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 85 | static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, |
Miklos Szeredi | 3e01cee | 2014-12-13 00:59:45 +0100 | [diff] [blame] | 86 | const char *name, int len, |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 87 | u64 ino, unsigned int d_type) |
| 88 | { |
| 89 | struct ovl_cache_entry *p; |
Al Viro | 68bf861 | 2014-10-23 22:58:56 -0400 | [diff] [blame] | 90 | size_t size = offsetof(struct ovl_cache_entry, name[len + 1]); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 91 | |
Al Viro | 68bf861 | 2014-10-23 22:58:56 -0400 | [diff] [blame] | 92 | p = kmalloc(size, GFP_KERNEL); |
Miklos Szeredi | 3e01cee | 2014-12-13 00:59:45 +0100 | [diff] [blame] | 93 | if (!p) |
| 94 | return NULL; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 95 | |
Miklos Szeredi | 3e01cee | 2014-12-13 00:59:45 +0100 | [diff] [blame] | 96 | memcpy(p->name, name, len); |
| 97 | p->name[len] = '\0'; |
| 98 | p->len = len; |
| 99 | p->type = d_type; |
| 100 | p->ino = ino; |
| 101 | p->is_whiteout = false; |
Miklos Szeredi | 3e01cee | 2014-12-13 00:59:45 +0100 | [diff] [blame] | 102 | |
| 103 | if (d_type == DT_CHR) { |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 104 | p->next_maybe_whiteout = rdd->first_maybe_whiteout; |
| 105 | rdd->first_maybe_whiteout = p; |
Miklos Szeredi | 3e01cee | 2014-12-13 00:59:45 +0100 | [diff] [blame] | 106 | } |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 107 | return p; |
| 108 | } |
| 109 | |
| 110 | static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd, |
| 111 | const char *name, int len, u64 ino, |
| 112 | unsigned int d_type) |
| 113 | { |
Al Viro | 49be4fb | 2014-10-23 23:00:53 -0400 | [diff] [blame] | 114 | struct rb_node **newp = &rdd->root.rb_node; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 115 | struct rb_node *parent = NULL; |
| 116 | struct ovl_cache_entry *p; |
| 117 | |
| 118 | while (*newp) { |
| 119 | int cmp; |
| 120 | struct ovl_cache_entry *tmp; |
| 121 | |
| 122 | parent = *newp; |
| 123 | tmp = ovl_cache_entry_from_node(*newp); |
| 124 | cmp = strncmp(name, tmp->name, len); |
| 125 | if (cmp > 0) |
| 126 | newp = &tmp->node.rb_right; |
| 127 | else if (cmp < 0 || len < tmp->len) |
| 128 | newp = &tmp->node.rb_left; |
| 129 | else |
| 130 | return 0; |
| 131 | } |
| 132 | |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 133 | p = ovl_cache_entry_new(rdd, name, len, ino, d_type); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 134 | if (p == NULL) |
| 135 | return -ENOMEM; |
| 136 | |
| 137 | list_add_tail(&p->l_node, rdd->list); |
| 138 | rb_link_node(&p->node, parent, newp); |
Al Viro | 49be4fb | 2014-10-23 23:00:53 -0400 | [diff] [blame] | 139 | rb_insert_color(&p->node, &rdd->root); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | |
Miklos Szeredi | 56656e9 | 2016-03-21 17:31:46 +0100 | [diff] [blame] | 144 | static int ovl_fill_lowest(struct ovl_readdir_data *rdd, |
| 145 | const char *name, int namelen, |
| 146 | loff_t offset, u64 ino, unsigned int d_type) |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 147 | { |
| 148 | struct ovl_cache_entry *p; |
| 149 | |
Al Viro | 49be4fb | 2014-10-23 23:00:53 -0400 | [diff] [blame] | 150 | p = ovl_cache_entry_find(&rdd->root, name, namelen); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 151 | if (p) { |
Al Viro | db6ec21 | 2014-10-23 23:03:03 -0400 | [diff] [blame] | 152 | list_move_tail(&p->l_node, &rdd->middle); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 153 | } else { |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 154 | p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 155 | if (p == NULL) |
| 156 | rdd->err = -ENOMEM; |
| 157 | else |
Al Viro | db6ec21 | 2014-10-23 23:03:03 -0400 | [diff] [blame] | 158 | list_add_tail(&p->l_node, &rdd->middle); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | return rdd->err; |
| 162 | } |
| 163 | |
| 164 | void ovl_cache_free(struct list_head *list) |
| 165 | { |
| 166 | struct ovl_cache_entry *p; |
| 167 | struct ovl_cache_entry *n; |
| 168 | |
| 169 | list_for_each_entry_safe(p, n, list, l_node) |
| 170 | kfree(p); |
| 171 | |
| 172 | INIT_LIST_HEAD(list); |
| 173 | } |
| 174 | |
| 175 | static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) |
| 176 | { |
| 177 | struct ovl_dir_cache *cache = od->cache; |
| 178 | |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 179 | WARN_ON(cache->refcount <= 0); |
| 180 | cache->refcount--; |
| 181 | if (!cache->refcount) { |
| 182 | if (ovl_dir_cache(dentry) == cache) |
| 183 | ovl_set_dir_cache(dentry, NULL); |
| 184 | |
| 185 | ovl_cache_free(&cache->entries); |
| 186 | kfree(cache); |
| 187 | } |
| 188 | } |
| 189 | |
Miklos Szeredi | ac7576f | 2014-10-30 17:37:34 +0100 | [diff] [blame] | 190 | static int ovl_fill_merge(struct dir_context *ctx, const char *name, |
| 191 | int namelen, loff_t offset, u64 ino, |
| 192 | unsigned int d_type) |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 193 | { |
Miklos Szeredi | ac7576f | 2014-10-30 17:37:34 +0100 | [diff] [blame] | 194 | struct ovl_readdir_data *rdd = |
| 195 | container_of(ctx, struct ovl_readdir_data, ctx); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 196 | |
| 197 | rdd->count++; |
Miklos Szeredi | 56656e9 | 2016-03-21 17:31:46 +0100 | [diff] [blame] | 198 | if (!rdd->is_lowest) |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 199 | return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type); |
| 200 | else |
Miklos Szeredi | 56656e9 | 2016-03-21 17:31:46 +0100 | [diff] [blame] | 201 | return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 202 | } |
| 203 | |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 204 | static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd) |
| 205 | { |
| 206 | int err; |
| 207 | struct ovl_cache_entry *p; |
| 208 | struct dentry *dentry; |
| 209 | const struct cred *old_cred; |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 210 | |
Antonio Murdaca | 3fe6e52 | 2016-04-07 15:48:25 +0200 | [diff] [blame] | 211 | old_cred = ovl_override_creds(rdd->dentry->d_sb); |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 212 | |
Al Viro | 0023541 | 2016-05-26 00:05:12 -0400 | [diff] [blame] | 213 | err = down_write_killable(&dir->d_inode->i_rwsem); |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 214 | if (!err) { |
| 215 | while (rdd->first_maybe_whiteout) { |
| 216 | p = rdd->first_maybe_whiteout; |
| 217 | rdd->first_maybe_whiteout = p->next_maybe_whiteout; |
| 218 | dentry = lookup_one_len(p->name, dir, p->len); |
| 219 | if (!IS_ERR(dentry)) { |
| 220 | p->is_whiteout = ovl_is_whiteout(dentry); |
| 221 | dput(dentry); |
| 222 | } |
| 223 | } |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 224 | inode_unlock(dir->d_inode); |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 225 | } |
| 226 | revert_creds(old_cred); |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 227 | |
| 228 | return err; |
| 229 | } |
| 230 | |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 231 | static inline int ovl_dir_read(struct path *realpath, |
| 232 | struct ovl_readdir_data *rdd) |
| 233 | { |
| 234 | struct file *realfile; |
| 235 | int err; |
| 236 | |
| 237 | realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY); |
| 238 | if (IS_ERR(realfile)) |
| 239 | return PTR_ERR(realfile); |
| 240 | |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 241 | rdd->first_maybe_whiteout = NULL; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 242 | rdd->ctx.pos = 0; |
| 243 | do { |
| 244 | rdd->count = 0; |
| 245 | rdd->err = 0; |
| 246 | err = iterate_dir(realfile, &rdd->ctx); |
| 247 | if (err >= 0) |
| 248 | err = rdd->err; |
| 249 | } while (!err && rdd->count); |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 250 | |
Miklos Szeredi | eea2fb4 | 2016-09-01 11:11:59 +0200 | [diff] [blame] | 251 | if (!err && rdd->first_maybe_whiteout && rdd->dentry) |
Miklos Szeredi | cdb6727 | 2015-06-22 13:53:48 +0200 | [diff] [blame] | 252 | err = ovl_check_whiteouts(realpath->dentry, rdd); |
| 253 | |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 254 | fput(realfile); |
| 255 | |
| 256 | return err; |
| 257 | } |
| 258 | |
| 259 | static void ovl_dir_reset(struct file *file) |
| 260 | { |
| 261 | struct ovl_dir_file *od = file->private_data; |
| 262 | struct ovl_dir_cache *cache = od->cache; |
| 263 | struct dentry *dentry = file->f_path.dentry; |
| 264 | enum ovl_path_type type = ovl_path_type(dentry); |
| 265 | |
| 266 | if (cache && ovl_dentry_version_get(dentry) != cache->version) { |
| 267 | ovl_cache_put(od, dentry); |
| 268 | od->cache = NULL; |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 269 | od->cursor = NULL; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 270 | } |
Miklos Szeredi | 1afaba1 | 2014-12-13 00:59:42 +0100 | [diff] [blame] | 271 | WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type)); |
| 272 | if (od->is_real && OVL_TYPE_MERGE(type)) |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 273 | od->is_real = false; |
| 274 | } |
| 275 | |
Miklos Szeredi | c9f00fd | 2014-11-20 16:40:01 +0100 | [diff] [blame] | 276 | static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 277 | { |
| 278 | int err; |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 279 | struct path realpath; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 280 | struct ovl_readdir_data rdd = { |
| 281 | .ctx.actor = ovl_fill_merge, |
Antonio Murdaca | 3fe6e52 | 2016-04-07 15:48:25 +0200 | [diff] [blame] | 282 | .dentry = dentry, |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 283 | .list = list, |
Al Viro | 49be4fb | 2014-10-23 23:00:53 -0400 | [diff] [blame] | 284 | .root = RB_ROOT, |
Miklos Szeredi | 56656e9 | 2016-03-21 17:31:46 +0100 | [diff] [blame] | 285 | .is_lowest = false, |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 286 | }; |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 287 | int idx, next; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 288 | |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 289 | for (idx = 0; idx != -1; idx = next) { |
| 290 | next = ovl_path_next(idx, dentry, &realpath); |
Miklos Szeredi | c9f00fd | 2014-11-20 16:40:01 +0100 | [diff] [blame] | 291 | |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 292 | if (next != -1) { |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 293 | err = ovl_dir_read(&realpath, &rdd); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 294 | if (err) |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 295 | break; |
| 296 | } else { |
| 297 | /* |
| 298 | * Insert lowest layer entries before upper ones, this |
| 299 | * allows offsets to be reasonably constant |
| 300 | */ |
| 301 | list_add(&rdd.middle, rdd.list); |
Miklos Szeredi | 56656e9 | 2016-03-21 17:31:46 +0100 | [diff] [blame] | 302 | rdd.is_lowest = true; |
Miklos Szeredi | 9d7459d | 2014-12-13 00:59:44 +0100 | [diff] [blame] | 303 | err = ovl_dir_read(&realpath, &rdd); |
| 304 | list_del(&rdd.middle); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 305 | } |
| 306 | } |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 307 | return err; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 308 | } |
| 309 | |
| 310 | static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos) |
| 311 | { |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 312 | struct list_head *p; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 313 | loff_t off = 0; |
| 314 | |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 315 | list_for_each(p, &od->cache->entries) { |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 316 | if (off >= pos) |
| 317 | break; |
| 318 | off++; |
| 319 | } |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 320 | /* Cursor is safe since the cache is stable */ |
| 321 | od->cursor = p; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) |
| 325 | { |
| 326 | int res; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 327 | struct ovl_dir_cache *cache; |
| 328 | |
| 329 | cache = ovl_dir_cache(dentry); |
| 330 | if (cache && ovl_dentry_version_get(dentry) == cache->version) { |
| 331 | cache->refcount++; |
| 332 | return cache; |
| 333 | } |
| 334 | ovl_set_dir_cache(dentry, NULL); |
| 335 | |
| 336 | cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); |
| 337 | if (!cache) |
| 338 | return ERR_PTR(-ENOMEM); |
| 339 | |
| 340 | cache->refcount = 1; |
| 341 | INIT_LIST_HEAD(&cache->entries); |
| 342 | |
Miklos Szeredi | c9f00fd | 2014-11-20 16:40:01 +0100 | [diff] [blame] | 343 | res = ovl_dir_read_merged(dentry, &cache->entries); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 344 | if (res) { |
| 345 | ovl_cache_free(&cache->entries); |
| 346 | kfree(cache); |
| 347 | return ERR_PTR(res); |
| 348 | } |
| 349 | |
| 350 | cache->version = ovl_dentry_version_get(dentry); |
| 351 | ovl_set_dir_cache(dentry, cache); |
| 352 | |
| 353 | return cache; |
| 354 | } |
| 355 | |
| 356 | static int ovl_iterate(struct file *file, struct dir_context *ctx) |
| 357 | { |
| 358 | struct ovl_dir_file *od = file->private_data; |
| 359 | struct dentry *dentry = file->f_path.dentry; |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 360 | struct ovl_cache_entry *p; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 361 | |
| 362 | if (!ctx->pos) |
| 363 | ovl_dir_reset(file); |
| 364 | |
| 365 | if (od->is_real) |
| 366 | return iterate_dir(od->realfile, ctx); |
| 367 | |
| 368 | if (!od->cache) { |
| 369 | struct ovl_dir_cache *cache; |
| 370 | |
| 371 | cache = ovl_cache_get(dentry); |
| 372 | if (IS_ERR(cache)) |
| 373 | return PTR_ERR(cache); |
| 374 | |
| 375 | od->cache = cache; |
| 376 | ovl_seek_cursor(od, ctx->pos); |
| 377 | } |
| 378 | |
hujianyang | 4330397 | 2014-12-11 10:30:18 +0800 | [diff] [blame] | 379 | while (od->cursor != &od->cache->entries) { |
| 380 | p = list_entry(od->cursor, struct ovl_cache_entry, l_node); |
| 381 | if (!p->is_whiteout) |
| 382 | if (!dir_emit(ctx, p->name, p->len, p->ino, p->type)) |
| 383 | break; |
| 384 | od->cursor = p->l_node.next; |
| 385 | ctx->pos++; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 386 | } |
| 387 | return 0; |
| 388 | } |
| 389 | |
| 390 | static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin) |
| 391 | { |
| 392 | loff_t res; |
| 393 | struct ovl_dir_file *od = file->private_data; |
| 394 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 395 | inode_lock(file_inode(file)); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 396 | if (!file->f_pos) |
| 397 | ovl_dir_reset(file); |
| 398 | |
| 399 | if (od->is_real) { |
| 400 | res = vfs_llseek(od->realfile, offset, origin); |
| 401 | file->f_pos = od->realfile->f_pos; |
| 402 | } else { |
| 403 | res = -EINVAL; |
| 404 | |
| 405 | switch (origin) { |
| 406 | case SEEK_CUR: |
| 407 | offset += file->f_pos; |
| 408 | break; |
| 409 | case SEEK_SET: |
| 410 | break; |
| 411 | default: |
| 412 | goto out_unlock; |
| 413 | } |
| 414 | if (offset < 0) |
| 415 | goto out_unlock; |
| 416 | |
| 417 | if (offset != file->f_pos) { |
| 418 | file->f_pos = offset; |
| 419 | if (od->cache) |
| 420 | ovl_seek_cursor(od, offset); |
| 421 | } |
| 422 | res = offset; |
| 423 | } |
| 424 | out_unlock: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 425 | inode_unlock(file_inode(file)); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 426 | |
| 427 | return res; |
| 428 | } |
| 429 | |
| 430 | static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, |
| 431 | int datasync) |
| 432 | { |
| 433 | struct ovl_dir_file *od = file->private_data; |
| 434 | struct dentry *dentry = file->f_path.dentry; |
| 435 | struct file *realfile = od->realfile; |
| 436 | |
| 437 | /* |
| 438 | * Need to check if we started out being a lower dir, but got copied up |
| 439 | */ |
Miklos Szeredi | 1afaba1 | 2014-12-13 00:59:42 +0100 | [diff] [blame] | 440 | if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) { |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 441 | struct inode *inode = file_inode(file); |
| 442 | |
Miklos Szeredi | 7676895 | 2014-11-20 16:40:02 +0100 | [diff] [blame] | 443 | realfile = lockless_dereference(od->upperfile); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 444 | if (!realfile) { |
| 445 | struct path upperpath; |
| 446 | |
| 447 | ovl_path_upper(dentry, &upperpath); |
| 448 | realfile = ovl_path_open(&upperpath, O_RDONLY); |
Al Viro | d45f00a | 2014-10-28 18:27:28 -0400 | [diff] [blame] | 449 | smp_mb__before_spinlock(); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 450 | inode_lock(inode); |
Al Viro | 3d268c9 | 2014-10-23 22:56:05 -0400 | [diff] [blame] | 451 | if (!od->upperfile) { |
| 452 | if (IS_ERR(realfile)) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 453 | inode_unlock(inode); |
Al Viro | 3d268c9 | 2014-10-23 22:56:05 -0400 | [diff] [blame] | 454 | return PTR_ERR(realfile); |
| 455 | } |
| 456 | od->upperfile = realfile; |
| 457 | } else { |
| 458 | /* somebody has beaten us to it */ |
| 459 | if (!IS_ERR(realfile)) |
| 460 | fput(realfile); |
| 461 | realfile = od->upperfile; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 462 | } |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 463 | inode_unlock(inode); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 464 | } |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 465 | } |
| 466 | |
| 467 | return vfs_fsync_range(realfile, start, end, datasync); |
| 468 | } |
| 469 | |
| 470 | static int ovl_dir_release(struct inode *inode, struct file *file) |
| 471 | { |
| 472 | struct ovl_dir_file *od = file->private_data; |
| 473 | |
| 474 | if (od->cache) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 475 | inode_lock(inode); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 476 | ovl_cache_put(od, file->f_path.dentry); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 477 | inode_unlock(inode); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 478 | } |
| 479 | fput(od->realfile); |
| 480 | if (od->upperfile) |
| 481 | fput(od->upperfile); |
| 482 | kfree(od); |
| 483 | |
| 484 | return 0; |
| 485 | } |
| 486 | |
| 487 | static int ovl_dir_open(struct inode *inode, struct file *file) |
| 488 | { |
| 489 | struct path realpath; |
| 490 | struct file *realfile; |
| 491 | struct ovl_dir_file *od; |
| 492 | enum ovl_path_type type; |
| 493 | |
| 494 | od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL); |
| 495 | if (!od) |
| 496 | return -ENOMEM; |
| 497 | |
| 498 | type = ovl_path_real(file->f_path.dentry, &realpath); |
| 499 | realfile = ovl_path_open(&realpath, file->f_flags); |
| 500 | if (IS_ERR(realfile)) { |
| 501 | kfree(od); |
| 502 | return PTR_ERR(realfile); |
| 503 | } |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 504 | od->realfile = realfile; |
Miklos Szeredi | 1afaba1 | 2014-12-13 00:59:42 +0100 | [diff] [blame] | 505 | od->is_real = !OVL_TYPE_MERGE(type); |
| 506 | od->is_upper = OVL_TYPE_UPPER(type); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 507 | file->private_data = od; |
| 508 | |
| 509 | return 0; |
| 510 | } |
| 511 | |
| 512 | const struct file_operations ovl_dir_operations = { |
| 513 | .read = generic_read_dir, |
| 514 | .open = ovl_dir_open, |
| 515 | .iterate = ovl_iterate, |
| 516 | .llseek = ovl_dir_llseek, |
| 517 | .fsync = ovl_dir_fsync, |
| 518 | .release = ovl_dir_release, |
| 519 | }; |
| 520 | |
| 521 | int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) |
| 522 | { |
| 523 | int err; |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 524 | struct ovl_cache_entry *p; |
| 525 | |
Miklos Szeredi | c9f00fd | 2014-11-20 16:40:01 +0100 | [diff] [blame] | 526 | err = ovl_dir_read_merged(dentry, list); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 527 | if (err) |
| 528 | return err; |
| 529 | |
| 530 | err = 0; |
| 531 | |
| 532 | list_for_each_entry(p, list, l_node) { |
| 533 | if (p->is_whiteout) |
| 534 | continue; |
| 535 | |
| 536 | if (p->name[0] == '.') { |
| 537 | if (p->len == 1) |
| 538 | continue; |
| 539 | if (p->len == 2 && p->name[1] == '.') |
| 540 | continue; |
| 541 | } |
| 542 | err = -ENOTEMPTY; |
| 543 | break; |
| 544 | } |
| 545 | |
| 546 | return err; |
| 547 | } |
| 548 | |
| 549 | void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) |
| 550 | { |
| 551 | struct ovl_cache_entry *p; |
| 552 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 553 | inode_lock_nested(upper->d_inode, I_MUTEX_CHILD); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 554 | list_for_each_entry(p, list, l_node) { |
| 555 | struct dentry *dentry; |
| 556 | |
| 557 | if (!p->is_whiteout) |
| 558 | continue; |
| 559 | |
| 560 | dentry = lookup_one_len(p->name, upper, p->len); |
| 561 | if (IS_ERR(dentry)) { |
| 562 | pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n", |
| 563 | upper->d_name.name, p->len, p->name, |
| 564 | (int) PTR_ERR(dentry)); |
| 565 | continue; |
| 566 | } |
Konstantin Khlebnikov | 84889d4 | 2015-11-16 18:44:11 +0300 | [diff] [blame] | 567 | if (dentry->d_inode) |
| 568 | ovl_cleanup(upper->d_inode, dentry); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 569 | dput(dentry); |
| 570 | } |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 571 | inode_unlock(upper->d_inode); |
Miklos Szeredi | e9be9d5 | 2014-10-24 00:14:38 +0200 | [diff] [blame] | 572 | } |
Vivek Goyal | 45aebea | 2016-02-22 09:28:34 -0500 | [diff] [blame] | 573 | |
| 574 | static int ovl_check_d_type(struct dir_context *ctx, const char *name, |
| 575 | int namelen, loff_t offset, u64 ino, |
| 576 | unsigned int d_type) |
| 577 | { |
| 578 | struct ovl_readdir_data *rdd = |
| 579 | container_of(ctx, struct ovl_readdir_data, ctx); |
| 580 | |
| 581 | /* Even if d_type is not supported, DT_DIR is returned for . and .. */ |
| 582 | if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen)) |
| 583 | return 0; |
| 584 | |
| 585 | if (d_type != DT_UNKNOWN) |
| 586 | rdd->d_type_supported = true; |
| 587 | |
| 588 | return 0; |
| 589 | } |
| 590 | |
| 591 | /* |
| 592 | * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values |
| 593 | * if error is encountered. |
| 594 | */ |
| 595 | int ovl_check_d_type_supported(struct path *realpath) |
| 596 | { |
| 597 | int err; |
| 598 | struct ovl_readdir_data rdd = { |
| 599 | .ctx.actor = ovl_check_d_type, |
| 600 | .d_type_supported = false, |
| 601 | }; |
| 602 | |
| 603 | err = ovl_dir_read(realpath, &rdd); |
| 604 | if (err) |
| 605 | return err; |
| 606 | |
| 607 | return rdd.d_type_supported; |
| 608 | } |
Miklos Szeredi | eea2fb4 | 2016-09-01 11:11:59 +0200 | [diff] [blame] | 609 | |
| 610 | static void ovl_workdir_cleanup_recurse(struct path *path, int level) |
| 611 | { |
| 612 | int err; |
| 613 | struct inode *dir = path->dentry->d_inode; |
| 614 | LIST_HEAD(list); |
| 615 | struct ovl_cache_entry *p; |
| 616 | struct ovl_readdir_data rdd = { |
| 617 | .ctx.actor = ovl_fill_merge, |
| 618 | .dentry = NULL, |
| 619 | .list = &list, |
| 620 | .root = RB_ROOT, |
| 621 | .is_lowest = false, |
| 622 | }; |
| 623 | |
| 624 | err = ovl_dir_read(path, &rdd); |
| 625 | if (err) |
| 626 | goto out; |
| 627 | |
| 628 | inode_lock_nested(dir, I_MUTEX_PARENT); |
| 629 | list_for_each_entry(p, &list, l_node) { |
| 630 | struct dentry *dentry; |
| 631 | |
| 632 | if (p->name[0] == '.') { |
| 633 | if (p->len == 1) |
| 634 | continue; |
| 635 | if (p->len == 2 && p->name[1] == '.') |
| 636 | continue; |
| 637 | } |
| 638 | dentry = lookup_one_len(p->name, path->dentry, p->len); |
| 639 | if (IS_ERR(dentry)) |
| 640 | continue; |
| 641 | if (dentry->d_inode) |
| 642 | ovl_workdir_cleanup(dir, path->mnt, dentry, level); |
| 643 | dput(dentry); |
| 644 | } |
| 645 | inode_unlock(dir); |
| 646 | out: |
| 647 | ovl_cache_free(&list); |
| 648 | } |
| 649 | |
| 650 | void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, |
| 651 | struct dentry *dentry, int level) |
| 652 | { |
| 653 | int err; |
| 654 | |
| 655 | if (!d_is_dir(dentry) || level > 1) { |
| 656 | ovl_cleanup(dir, dentry); |
| 657 | return; |
| 658 | } |
| 659 | |
| 660 | err = ovl_do_rmdir(dir, dentry); |
| 661 | if (err) { |
| 662 | struct path path = { .mnt = mnt, .dentry = dentry }; |
| 663 | |
| 664 | inode_unlock(dir); |
| 665 | ovl_workdir_cleanup_recurse(&path, level + 1); |
| 666 | inode_lock_nested(dir, I_MUTEX_PARENT); |
| 667 | ovl_cleanup(dir, dentry); |
| 668 | } |
| 669 | } |