2 * Copyright (C) 2011 Novell Inc.
3 * Copyright (C) 2016 Red Hat, Inc.
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.
11 #include <linux/mount.h>
12 #include <linux/slab.h>
13 #include <linux/xattr.h>
14 #include "overlayfs.h"
15 #include "ovl_entry.h"
17 int ovl_want_write(struct dentry *dentry)
19 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
20 return mnt_want_write(ofs->upper_mnt);
23 void ovl_drop_write(struct dentry *dentry)
25 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
26 mnt_drop_write(ofs->upper_mnt);
29 struct dentry *ovl_workdir(struct dentry *dentry)
31 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
35 const struct cred *ovl_override_creds(struct super_block *sb)
37 struct ovl_fs *ofs = sb->s_fs_info;
39 return override_creds(ofs->creator_cred);
42 struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
44 size_t size = offsetof(struct ovl_entry, lowerstack[numlower]);
45 struct ovl_entry *oe = kzalloc(size, GFP_KERNEL);
48 oe->numlower = numlower;
53 bool ovl_dentry_remote(struct dentry *dentry)
55 return dentry->d_flags &
56 (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE |
60 bool ovl_dentry_weird(struct dentry *dentry)
62 return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT |
63 DCACHE_MANAGE_TRANSIT |
68 enum ovl_path_type ovl_path_type(struct dentry *dentry)
70 struct ovl_entry *oe = dentry->d_fsdata;
71 enum ovl_path_type type = 0;
73 if (oe->__upperdentry) {
74 type = __OVL_PATH_UPPER;
77 * Non-dir dentry can hold lower dentry from previous
80 if (oe->numlower && d_is_dir(dentry))
81 type |= __OVL_PATH_MERGE;
84 type |= __OVL_PATH_MERGE;
89 void ovl_path_upper(struct dentry *dentry, struct path *path)
91 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
92 struct ovl_entry *oe = dentry->d_fsdata;
94 path->mnt = ofs->upper_mnt;
95 path->dentry = ovl_upperdentry_dereference(oe);
98 void ovl_path_lower(struct dentry *dentry, struct path *path)
100 struct ovl_entry *oe = dentry->d_fsdata;
102 *path = oe->numlower ? oe->lowerstack[0] : (struct path) { NULL, NULL };
105 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path)
107 enum ovl_path_type type = ovl_path_type(dentry);
109 if (!OVL_TYPE_UPPER(type))
110 ovl_path_lower(dentry, path);
112 ovl_path_upper(dentry, path);
117 struct dentry *ovl_dentry_upper(struct dentry *dentry)
119 struct ovl_entry *oe = dentry->d_fsdata;
121 return ovl_upperdentry_dereference(oe);
124 static struct dentry *__ovl_dentry_lower(struct ovl_entry *oe)
126 return oe->numlower ? oe->lowerstack[0].dentry : NULL;
129 struct dentry *ovl_dentry_lower(struct dentry *dentry)
131 struct ovl_entry *oe = dentry->d_fsdata;
133 return __ovl_dentry_lower(oe);
136 struct dentry *ovl_dentry_real(struct dentry *dentry)
138 struct ovl_entry *oe = dentry->d_fsdata;
139 struct dentry *realdentry;
141 realdentry = ovl_upperdentry_dereference(oe);
143 realdentry = __ovl_dentry_lower(oe);
148 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry)
150 struct ovl_entry *oe = dentry->d_fsdata;
155 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache)
157 struct ovl_entry *oe = dentry->d_fsdata;
162 bool ovl_dentry_is_opaque(struct dentry *dentry)
164 struct ovl_entry *oe = dentry->d_fsdata;
168 bool ovl_dentry_is_whiteout(struct dentry *dentry)
170 return !dentry->d_inode && ovl_dentry_is_opaque(dentry);
173 void ovl_dentry_set_opaque(struct dentry *dentry)
175 struct ovl_entry *oe = dentry->d_fsdata;
180 bool ovl_redirect_dir(struct super_block *sb)
182 struct ovl_fs *ofs = sb->s_fs_info;
184 return ofs->config.redirect_dir;
187 void ovl_clear_redirect_dir(struct super_block *sb)
189 struct ovl_fs *ofs = sb->s_fs_info;
191 ofs->config.redirect_dir = false;
194 const char *ovl_dentry_get_redirect(struct dentry *dentry)
196 struct ovl_entry *oe = dentry->d_fsdata;
201 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect)
203 struct ovl_entry *oe = dentry->d_fsdata;
206 oe->redirect = redirect;
209 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
211 struct ovl_entry *oe = dentry->d_fsdata;
213 WARN_ON(!inode_is_locked(upperdentry->d_parent->d_inode));
214 WARN_ON(oe->__upperdentry);
216 * Make sure upperdentry is consistent before making it visible to
217 * ovl_upperdentry_dereference().
220 oe->__upperdentry = upperdentry;
223 void ovl_inode_init(struct inode *inode, struct inode *realinode, bool is_upper)
225 WRITE_ONCE(inode->i_private, (unsigned long) realinode |
226 (is_upper ? OVL_ISUPPER_MASK : 0));
229 void ovl_inode_update(struct inode *inode, struct inode *upperinode)
231 WARN_ON(!upperinode);
232 WARN_ON(!inode_unhashed(inode));
233 WRITE_ONCE(inode->i_private,
234 (unsigned long) upperinode | OVL_ISUPPER_MASK);
235 if (!S_ISDIR(upperinode->i_mode))
236 __insert_inode_hash(inode, (unsigned long) upperinode);
239 void ovl_dentry_version_inc(struct dentry *dentry)
241 struct ovl_entry *oe = dentry->d_fsdata;
243 WARN_ON(!inode_is_locked(dentry->d_inode));
247 u64 ovl_dentry_version_get(struct dentry *dentry)
249 struct ovl_entry *oe = dentry->d_fsdata;
251 WARN_ON(!inode_is_locked(dentry->d_inode));
255 bool ovl_is_whiteout(struct dentry *dentry)
257 struct inode *inode = dentry->d_inode;
259 return inode && IS_WHITEOUT(inode);
262 struct file *ovl_path_open(struct path *path, int flags)
264 return dentry_open(path, flags | O_NOATIME, current_cred());
267 int ovl_copy_up_start(struct dentry *dentry)
269 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
270 struct ovl_entry *oe = dentry->d_fsdata;
273 spin_lock(&ofs->copyup_wq.lock);
274 err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying);
276 if (oe->__upperdentry)
277 err = 1; /* Already copied up */
281 spin_unlock(&ofs->copyup_wq.lock);
286 void ovl_copy_up_end(struct dentry *dentry)
288 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
289 struct ovl_entry *oe = dentry->d_fsdata;
291 spin_lock(&ofs->copyup_wq.lock);
293 wake_up_locked(&ofs->copyup_wq);
294 spin_unlock(&ofs->copyup_wq.lock);