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/cred.h>
14 #include <linux/xattr.h>
15 #include "overlayfs.h"
16 #include "ovl_entry.h"
18 int ovl_want_write(struct dentry
*dentry
)
20 struct ovl_fs
*ofs
= dentry
->d_sb
->s_fs_info
;
21 return mnt_want_write(ofs
->upper_mnt
);
24 void ovl_drop_write(struct dentry
*dentry
)
26 struct ovl_fs
*ofs
= dentry
->d_sb
->s_fs_info
;
27 mnt_drop_write(ofs
->upper_mnt
);
30 struct dentry
*ovl_workdir(struct dentry
*dentry
)
32 struct ovl_fs
*ofs
= dentry
->d_sb
->s_fs_info
;
36 const struct cred
*ovl_override_creds(struct super_block
*sb
)
38 struct ovl_fs
*ofs
= sb
->s_fs_info
;
40 return override_creds(ofs
->creator_cred
);
43 struct ovl_entry
*ovl_alloc_entry(unsigned int numlower
)
45 size_t size
= offsetof(struct ovl_entry
, lowerstack
[numlower
]);
46 struct ovl_entry
*oe
= kzalloc(size
, GFP_KERNEL
);
49 oe
->numlower
= numlower
;
54 bool ovl_dentry_remote(struct dentry
*dentry
)
56 return dentry
->d_flags
&
57 (DCACHE_OP_REVALIDATE
| DCACHE_OP_WEAK_REVALIDATE
|
61 bool ovl_dentry_weird(struct dentry
*dentry
)
63 return dentry
->d_flags
& (DCACHE_NEED_AUTOMOUNT
|
64 DCACHE_MANAGE_TRANSIT
|
69 enum ovl_path_type
ovl_path_type(struct dentry
*dentry
)
71 struct ovl_entry
*oe
= dentry
->d_fsdata
;
72 enum ovl_path_type type
= 0;
74 if (oe
->__upperdentry
) {
75 type
= __OVL_PATH_UPPER
;
78 * Non-dir dentry can hold lower dentry from previous
81 if (oe
->numlower
&& d_is_dir(dentry
))
82 type
|= __OVL_PATH_MERGE
;
85 type
|= __OVL_PATH_MERGE
;
90 void ovl_path_upper(struct dentry
*dentry
, struct path
*path
)
92 struct ovl_fs
*ofs
= dentry
->d_sb
->s_fs_info
;
93 struct ovl_entry
*oe
= dentry
->d_fsdata
;
95 path
->mnt
= ofs
->upper_mnt
;
96 path
->dentry
= ovl_upperdentry_dereference(oe
);
99 void ovl_path_lower(struct dentry
*dentry
, struct path
*path
)
101 struct ovl_entry
*oe
= dentry
->d_fsdata
;
103 *path
= oe
->numlower
? oe
->lowerstack
[0] : (struct path
) { NULL
, NULL
};
106 enum ovl_path_type
ovl_path_real(struct dentry
*dentry
, struct path
*path
)
108 enum ovl_path_type type
= ovl_path_type(dentry
);
110 if (!OVL_TYPE_UPPER(type
))
111 ovl_path_lower(dentry
, path
);
113 ovl_path_upper(dentry
, path
);
118 struct dentry
*ovl_dentry_upper(struct dentry
*dentry
)
120 struct ovl_entry
*oe
= dentry
->d_fsdata
;
122 return ovl_upperdentry_dereference(oe
);
125 static struct dentry
*__ovl_dentry_lower(struct ovl_entry
*oe
)
127 return oe
->numlower
? oe
->lowerstack
[0].dentry
: NULL
;
130 struct dentry
*ovl_dentry_lower(struct dentry
*dentry
)
132 struct ovl_entry
*oe
= dentry
->d_fsdata
;
134 return __ovl_dentry_lower(oe
);
137 struct dentry
*ovl_dentry_real(struct dentry
*dentry
)
139 struct ovl_entry
*oe
= dentry
->d_fsdata
;
140 struct dentry
*realdentry
;
142 realdentry
= ovl_upperdentry_dereference(oe
);
144 realdentry
= __ovl_dentry_lower(oe
);
149 struct ovl_dir_cache
*ovl_dir_cache(struct dentry
*dentry
)
151 struct ovl_entry
*oe
= dentry
->d_fsdata
;
156 void ovl_set_dir_cache(struct dentry
*dentry
, struct ovl_dir_cache
*cache
)
158 struct ovl_entry
*oe
= dentry
->d_fsdata
;
163 bool ovl_dentry_is_opaque(struct dentry
*dentry
)
165 struct ovl_entry
*oe
= dentry
->d_fsdata
;
169 bool ovl_dentry_is_whiteout(struct dentry
*dentry
)
171 return !dentry
->d_inode
&& ovl_dentry_is_opaque(dentry
);
174 void ovl_dentry_set_opaque(struct dentry
*dentry
)
176 struct ovl_entry
*oe
= dentry
->d_fsdata
;
181 bool ovl_redirect_dir(struct super_block
*sb
)
183 struct ovl_fs
*ofs
= sb
->s_fs_info
;
185 return ofs
->config
.redirect_dir
;
188 void ovl_clear_redirect_dir(struct super_block
*sb
)
190 struct ovl_fs
*ofs
= sb
->s_fs_info
;
192 ofs
->config
.redirect_dir
= false;
195 const char *ovl_dentry_get_redirect(struct dentry
*dentry
)
197 struct ovl_entry
*oe
= dentry
->d_fsdata
;
202 void ovl_dentry_set_redirect(struct dentry
*dentry
, const char *redirect
)
204 struct ovl_entry
*oe
= dentry
->d_fsdata
;
207 oe
->redirect
= redirect
;
210 void ovl_dentry_update(struct dentry
*dentry
, struct dentry
*upperdentry
)
212 struct ovl_entry
*oe
= dentry
->d_fsdata
;
214 WARN_ON(!inode_is_locked(upperdentry
->d_parent
->d_inode
));
215 WARN_ON(oe
->__upperdentry
);
217 * Make sure upperdentry is consistent before making it visible to
218 * ovl_upperdentry_dereference().
221 oe
->__upperdentry
= upperdentry
;
224 void ovl_inode_init(struct inode
*inode
, struct inode
*realinode
, bool is_upper
)
226 WRITE_ONCE(inode
->i_private
, (unsigned long) realinode
|
227 (is_upper
? OVL_ISUPPER_MASK
: 0));
230 void ovl_inode_update(struct inode
*inode
, struct inode
*upperinode
)
232 WARN_ON(!upperinode
);
233 WARN_ON(!inode_unhashed(inode
));
234 WRITE_ONCE(inode
->i_private
,
235 (unsigned long) upperinode
| OVL_ISUPPER_MASK
);
236 if (!S_ISDIR(upperinode
->i_mode
))
237 __insert_inode_hash(inode
, (unsigned long) upperinode
);
240 void ovl_dentry_version_inc(struct dentry
*dentry
)
242 struct ovl_entry
*oe
= dentry
->d_fsdata
;
244 WARN_ON(!inode_is_locked(dentry
->d_inode
));
248 u64
ovl_dentry_version_get(struct dentry
*dentry
)
250 struct ovl_entry
*oe
= dentry
->d_fsdata
;
252 WARN_ON(!inode_is_locked(dentry
->d_inode
));
256 bool ovl_is_whiteout(struct dentry
*dentry
)
258 struct inode
*inode
= dentry
->d_inode
;
260 return inode
&& IS_WHITEOUT(inode
);
263 struct file
*ovl_path_open(struct path
*path
, int flags
)
265 return dentry_open(path
, flags
| O_NOATIME
, current_cred());
268 int ovl_copy_up_start(struct dentry
*dentry
)
270 struct ovl_fs
*ofs
= dentry
->d_sb
->s_fs_info
;
271 struct ovl_entry
*oe
= dentry
->d_fsdata
;
274 spin_lock(&ofs
->copyup_wq
.lock
);
275 err
= wait_event_interruptible_locked(ofs
->copyup_wq
, !oe
->copying
);
277 if (oe
->__upperdentry
)
278 err
= 1; /* Already copied up */
282 spin_unlock(&ofs
->copyup_wq
.lock
);
287 void ovl_copy_up_end(struct dentry
*dentry
)
289 struct ovl_fs
*ofs
= dentry
->d_sb
->s_fs_info
;
290 struct ovl_entry
*oe
= dentry
->d_fsdata
;
292 spin_lock(&ofs
->copyup_wq
.lock
);
294 wake_up_locked(&ofs
->copyup_wq
);
295 spin_unlock(&ofs
->copyup_wq
.lock
);