blob: d82d2a043da2c7b7ea055a5c7dbbe0b3c2544dbc (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
*
* Copyright (C) 2011 Novell Inc.
* Copyright (C) 2016 Red Hat, Inc.
*/
struct ovl_config {
char *upperdir;
char *workdir;
char **lowerdirs;
bool default_permissions;
int redirect_mode;
int verity_mode;
bool index;
int uuid;
bool nfs_export;
int xino;
bool metacopy;
bool userxattr;
bool ovl_volatile;
};
struct ovl_sb {
struct super_block *sb;
dev_t pseudo_dev;
/* Unusable (conflicting) uuid */
bool bad_uuid;
/* Used as a lower layer (but maybe also as upper) */
bool is_lower;
};
struct ovl_layer {
/* ovl_free_fs() relies on @mnt being the first member! */
struct vfsmount *mnt;
/* Trap in ovl inode cache */
struct inode *trap;
struct ovl_sb *fs;
/* Index of this layer in fs root (upper idx == 0) */
int idx;
/* One fsid per unique underlying sb (upper fsid == 0) */
int fsid;
};
struct ovl_path {
const struct ovl_layer *layer;
struct dentry *dentry;
};
struct ovl_entry {
unsigned int __numlower;
struct ovl_path __lowerstack[];
};
/* private information held for overlayfs's superblock */
struct ovl_fs {
unsigned int numlayer;
/* Number of unique fs among layers including upper fs */
unsigned int numfs;
/* Number of data-only lower layers */
unsigned int numdatalayer;
const struct ovl_layer *layers;
struct ovl_sb *fs;
/* workbasedir is the path at workdir= mount option */
struct dentry *workbasedir;
/* workdir is the 'work' directory under workbasedir */
struct dentry *workdir;
/* index directory listing overlay inodes by origin file handle */
struct dentry *indexdir;
long namelen;
/* pathnames of lower and upper dirs, for show_options */
struct ovl_config config;
/* creds of process who forced instantiation of super block */
const struct cred *creator_cred;
bool tmpfile;
bool noxattr;
bool nofh;
/* Did we take the inuse lock? */
bool upperdir_locked;
bool workdir_locked;
/* Traps in ovl inode cache */
struct inode *workbasedir_trap;
struct inode *workdir_trap;
struct inode *indexdir_trap;
/* -1: disabled, 0: same fs, 1..32: number of unused ino bits */
int xino_mode;
/* For allocation of non-persistent inode numbers */
atomic_long_t last_ino;
/* Shared whiteout cache */
struct dentry *whiteout;
bool no_shared_whiteout;
/* r/o snapshot of upperdir sb's only taken on volatile mounts */
errseq_t errseq;
};
/* Number of lower layers, not including data-only layers */
static inline unsigned int ovl_numlowerlayer(struct ovl_fs *ofs)
{
return ofs->numlayer - ofs->numdatalayer - 1;
}
static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs)
{
return ofs->layers[0].mnt;
}
static inline struct mnt_idmap *ovl_upper_mnt_idmap(struct ovl_fs *ofs)
{
return mnt_idmap(ovl_upper_mnt(ofs));
}
extern struct file_system_type ovl_fs_type;
static inline struct ovl_fs *OVL_FS(struct super_block *sb)
{
if (IS_ENABLED(CONFIG_OVERLAY_FS_DEBUG))
WARN_ON_ONCE(sb->s_type != &ovl_fs_type);
return (struct ovl_fs *)sb->s_fs_info;
}
static inline bool ovl_should_sync(struct ovl_fs *ofs)
{
return !ofs->config.ovl_volatile;
}
static inline unsigned int ovl_numlower(struct ovl_entry *oe)
{
return oe ? oe->__numlower : 0;
}
static inline struct ovl_path *ovl_lowerstack(struct ovl_entry *oe)
{
return ovl_numlower(oe) ? oe->__lowerstack : NULL;
}
static inline struct ovl_path *ovl_lowerpath(struct ovl_entry *oe)
{
return ovl_lowerstack(oe);
}
static inline struct ovl_path *ovl_lowerdata(struct ovl_entry *oe)
{
struct ovl_path *lowerstack = ovl_lowerstack(oe);
return lowerstack ? &lowerstack[oe->__numlower - 1] : NULL;
}
/* May return NULL if lazy lookup of lowerdata is needed */
static inline struct dentry *ovl_lowerdata_dentry(struct ovl_entry *oe)
{
struct ovl_path *lowerdata = ovl_lowerdata(oe);
return lowerdata ? READ_ONCE(lowerdata->dentry) : NULL;
}
/* private information held for every overlayfs dentry */
static inline unsigned long *OVL_E_FLAGS(struct dentry *dentry)
{
return (unsigned long *) &dentry->d_fsdata;
}
struct ovl_inode {
union {
struct ovl_dir_cache *cache; /* directory */
const char *lowerdata_redirect; /* regular file */
};
const char *redirect;
u64 version;
unsigned long flags;
struct inode vfs_inode;
struct dentry *__upperdentry;
struct ovl_entry *oe;
/* synchronize copy up and more */
struct mutex lock;
};
static inline struct ovl_inode *OVL_I(struct inode *inode)
{
return container_of(inode, struct ovl_inode, vfs_inode);
}
static inline struct ovl_entry *OVL_I_E(struct inode *inode)
{
return inode ? OVL_I(inode)->oe : NULL;
}
static inline struct ovl_entry *OVL_E(struct dentry *dentry)
{
return OVL_I_E(d_inode(dentry));
}
static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi)
{
return READ_ONCE(oi->__upperdentry);
}
|
