xref: /openbmc/linux/fs/overlayfs/overlayfs.h (revision 8684014d)
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/kernel.h>
11 
12 struct ovl_entry;
13 
14 enum ovl_path_type {
15 	OVL_PATH_PURE_UPPER,
16 	OVL_PATH_UPPER,
17 	OVL_PATH_MERGE,
18 	OVL_PATH_LOWER,
19 };
20 
21 extern const char *ovl_opaque_xattr;
22 
23 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
24 {
25 	int err = vfs_rmdir(dir, dentry);
26 	pr_debug("rmdir(%pd2) = %i\n", dentry, err);
27 	return err;
28 }
29 
30 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
31 {
32 	int err = vfs_unlink(dir, dentry, NULL);
33 	pr_debug("unlink(%pd2) = %i\n", dentry, err);
34 	return err;
35 }
36 
37 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
38 			      struct dentry *new_dentry, bool debug)
39 {
40 	int err = vfs_link(old_dentry, dir, new_dentry, NULL);
41 	if (debug) {
42 		pr_debug("link(%pd2, %pd2) = %i\n",
43 			 old_dentry, new_dentry, err);
44 	}
45 	return err;
46 }
47 
48 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
49 			     umode_t mode, bool debug)
50 {
51 	int err = vfs_create(dir, dentry, mode, true);
52 	if (debug)
53 		pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
54 	return err;
55 }
56 
57 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
58 			       umode_t mode, bool debug)
59 {
60 	int err = vfs_mkdir(dir, dentry, mode);
61 	if (debug)
62 		pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
63 	return err;
64 }
65 
66 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
67 			       umode_t mode, dev_t dev, bool debug)
68 {
69 	int err = vfs_mknod(dir, dentry, mode, dev);
70 	if (debug) {
71 		pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
72 			 dentry, mode, dev, err);
73 	}
74 	return err;
75 }
76 
77 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
78 				 const char *oldname, bool debug)
79 {
80 	int err = vfs_symlink(dir, dentry, oldname);
81 	if (debug)
82 		pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
83 	return err;
84 }
85 
86 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
87 				  const void *value, size_t size, int flags)
88 {
89 	int err = vfs_setxattr(dentry, name, value, size, flags);
90 	pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
91 		 dentry, name, (int) size, (char *) value, flags, err);
92 	return err;
93 }
94 
95 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
96 {
97 	int err = vfs_removexattr(dentry, name);
98 	pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
99 	return err;
100 }
101 
102 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
103 				struct inode *newdir, struct dentry *newdentry,
104 				unsigned int flags)
105 {
106 	int err;
107 
108 	pr_debug("rename2(%pd2, %pd2, 0x%x)\n",
109 		 olddentry, newdentry, flags);
110 
111 	err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
112 
113 	if (err) {
114 		pr_debug("...rename2(%pd2, %pd2, ...) = %i\n",
115 			 olddentry, newdentry, err);
116 	}
117 	return err;
118 }
119 
120 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
121 {
122 	int err = vfs_whiteout(dir, dentry);
123 	pr_debug("whiteout(%pd2) = %i\n", dentry, err);
124 	return err;
125 }
126 
127 enum ovl_path_type ovl_path_type(struct dentry *dentry);
128 u64 ovl_dentry_version_get(struct dentry *dentry);
129 void ovl_dentry_version_inc(struct dentry *dentry);
130 void ovl_path_upper(struct dentry *dentry, struct path *path);
131 void ovl_path_lower(struct dentry *dentry, struct path *path);
132 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
133 struct dentry *ovl_dentry_upper(struct dentry *dentry);
134 struct dentry *ovl_dentry_lower(struct dentry *dentry);
135 struct dentry *ovl_dentry_real(struct dentry *dentry);
136 struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper);
137 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
138 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
139 struct dentry *ovl_workdir(struct dentry *dentry);
140 int ovl_want_write(struct dentry *dentry);
141 void ovl_drop_write(struct dentry *dentry);
142 bool ovl_dentry_is_opaque(struct dentry *dentry);
143 void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
144 bool ovl_is_whiteout(struct dentry *dentry);
145 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
146 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
147 			  unsigned int flags);
148 struct file *ovl_path_open(struct path *path, int flags);
149 
150 struct dentry *ovl_upper_create(struct dentry *upperdir, struct dentry *dentry,
151 				struct kstat *stat, const char *link);
152 
153 /* readdir.c */
154 extern const struct file_operations ovl_dir_operations;
155 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
156 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
157 void ovl_cache_free(struct list_head *list);
158 
159 /* inode.c */
160 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
161 int ovl_permission(struct inode *inode, int mask);
162 int ovl_setxattr(struct dentry *dentry, const char *name,
163 		 const void *value, size_t size, int flags);
164 ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
165 		     void *value, size_t size);
166 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
167 int ovl_removexattr(struct dentry *dentry, const char *name);
168 
169 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
170 			    struct ovl_entry *oe);
171 static inline void ovl_copyattr(struct inode *from, struct inode *to)
172 {
173 	to->i_uid = from->i_uid;
174 	to->i_gid = from->i_gid;
175 }
176 
177 /* dir.c */
178 extern const struct inode_operations ovl_dir_inode_operations;
179 struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
180 int ovl_create_real(struct inode *dir, struct dentry *newdentry,
181 		    struct kstat *stat, const char *link,
182 		    struct dentry *hardlink, bool debug);
183 void ovl_cleanup(struct inode *dir, struct dentry *dentry);
184 
185 /* copy_up.c */
186 int ovl_copy_up(struct dentry *dentry);
187 int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
188 		    struct path *lowerpath, struct kstat *stat,
189 		    struct iattr *attr);
190 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
191 int ovl_set_attr(struct dentry *upper, struct kstat *stat);
192