fs/overlayfs/overlayfs.h

   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 enum ovl_path_type {
  13         __OVL_PATH_UPPER        = (1 << 0),
  14         __OVL_PATH_MERGE        = (1 << 1),
  15 };
  16
  17 #define OVL_TYPE_UPPER(type)    ((type) & __OVL_PATH_UPPER)
  18 #define OVL_TYPE_MERGE(type)    ((type) & __OVL_PATH_MERGE)
  19
  20 #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
  21 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
  22 #define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
  23
  24 #define OVL_ISUPPER_MASK 1UL
  25
  26 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
  27 {
  28         int err = vfs_rmdir(dir, dentry);
  29         pr_debug("rmdir(%pd2) = %i\n", dentry, err);
  30         return err;
  31 }
  32
  33 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
  34 {
  35         int err = vfs_unlink(dir, dentry, NULL);
  36         pr_debug("unlink(%pd2) = %i\n", dentry, err);
  37         return err;
  38 }
  39
  40 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
  41                               struct dentry *new_dentry, bool debug)
  42 {
  43         int err = vfs_link(old_dentry, dir, new_dentry, NULL);
  44         if (debug) {
  45                 pr_debug("link(%pd2, %pd2) = %i\n",
  46                          old_dentry, new_dentry, err);
  47         }
  48         return err;
  49 }
  50
  51 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
  52                              umode_t mode, bool debug)
  53 {
  54         int err = vfs_create(dir, dentry, mode, true);
  55         if (debug)
  56                 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
  57         return err;
  58 }
  59
  60 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
  61                                umode_t mode, bool debug)
  62 {
  63         int err = vfs_mkdir(dir, dentry, mode);
  64         if (debug)
  65                 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
  66         return err;
  67 }
  68
  69 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
  70                                umode_t mode, dev_t dev, bool debug)
  71 {
  72         int err = vfs_mknod(dir, dentry, mode, dev);
  73         if (debug) {
  74                 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
  75                          dentry, mode, dev, err);
  76         }
  77         return err;
  78 }
  79
  80 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
  81                                  const char *oldname, bool debug)
  82 {
  83         int err = vfs_symlink(dir, dentry, oldname);
  84         if (debug)
  85                 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
  86         return err;
  87 }
  88
  89 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
  90                                   const void *value, size_t size, int flags)
  91 {
  92         int err = vfs_setxattr(dentry, name, value, size, flags);
  93         pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
  94                  dentry, name, (int) size, (char *) value, flags, err);
  95         return err;
  96 }
  97
  98 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
  99 {
 100         int err = vfs_removexattr(dentry, name);
 101         pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
 102         return err;
 103 }
 104
 105 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
 106                                 struct inode *newdir, struct dentry *newdentry,
 107                                 unsigned int flags)
 108 {
 109         int err;
 110
 111         pr_debug("rename(%pd2, %pd2, 0x%x)\n",
 112                  olddentry, newdentry, flags);
 113
 114         err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
 115
 116         if (err) {
 117                 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
 118                          olddentry, newdentry, err);
 119         }
 120         return err;
 121 }
 122
 123 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
 124 {
 125         int err = vfs_whiteout(dir, dentry);
 126         pr_debug("whiteout(%pd2) = %i\n", dentry, err);
 127         return err;
 128 }
 129
 130 static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)
 131 {
 132         unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
 133
 134         if (is_upper)
 135                 *is_upper = x & OVL_ISUPPER_MASK;
 136
 137         return (struct inode *) (x & ~OVL_ISUPPER_MASK);
 138 }
 139
 140 /* util.c */
 141 int ovl_want_write(struct dentry *dentry);
 142 void ovl_drop_write(struct dentry *dentry);
 143 struct dentry *ovl_workdir(struct dentry *dentry);
 144 const struct cred *ovl_override_creds(struct super_block *sb);
 145 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
 146 bool ovl_dentry_remote(struct dentry *dentry);
 147 bool ovl_dentry_weird(struct dentry *dentry);
 148 enum ovl_path_type ovl_path_type(struct dentry *dentry);
 149 void ovl_path_upper(struct dentry *dentry, struct path *path);
 150 void ovl_path_lower(struct dentry *dentry, struct path *path);
 151 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
 152 struct dentry *ovl_dentry_upper(struct dentry *dentry);
 153 struct dentry *ovl_dentry_lower(struct dentry *dentry);
 154 struct dentry *ovl_dentry_real(struct dentry *dentry);
 155 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
 156 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
 157 bool ovl_dentry_is_opaque(struct dentry *dentry);
 158 bool ovl_dentry_is_whiteout(struct dentry *dentry);
 159 void ovl_dentry_set_opaque(struct dentry *dentry);
 160 bool ovl_redirect_dir(struct super_block *sb);
 161 void ovl_clear_redirect_dir(struct super_block *sb);
 162 const char *ovl_dentry_get_redirect(struct dentry *dentry);
 163 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
 164 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
 165 void ovl_inode_init(struct inode *inode, struct inode *realinode,
 166                     bool is_upper);
 167 void ovl_inode_update(struct inode *inode, struct inode *upperinode);
 168 void ovl_dentry_version_inc(struct dentry *dentry);
 169 u64 ovl_dentry_version_get(struct dentry *dentry);
 170 bool ovl_is_whiteout(struct dentry *dentry);
 171 struct file *ovl_path_open(struct path *path, int flags);
 172
 173 /* namei.c */
 174 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
 175 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
 176 bool ovl_lower_positive(struct dentry *dentry);
 177
 178 /* readdir.c */
 179 extern const struct file_operations ovl_dir_operations;
 180 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
 181 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
 182 void ovl_cache_free(struct list_head *list);
 183 int ovl_check_d_type_supported(struct path *realpath);
 184 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 185                          struct dentry *dentry, int level);
 186
 187 /* inode.c */
 188 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
 189 int ovl_permission(struct inode *inode, int mask);
 190 int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
 191                   size_t size, int flags);
 192 int ovl_xattr_get(struct dentry *dentry, const char *name,
 193                   void *value, size_t size);
 194 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 195 struct posix_acl *ovl_get_acl(struct inode *inode, int type);
 196 int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
 197 int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
 198 bool ovl_is_private_xattr(const char *name);
 199
 200 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
 201 struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode);
 202 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 203 {
 204         to->i_uid = from->i_uid;
 205         to->i_gid = from->i_gid;
 206         to->i_mode = from->i_mode;
 207         to->i_atime = from->i_atime;
 208         to->i_mtime = from->i_mtime;
 209         to->i_ctime = from->i_ctime;
 210 }
 211
 212 /* dir.c */
 213 extern const struct inode_operations ovl_dir_inode_operations;
 214 struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
 215 struct cattr {
 216         dev_t rdev;
 217         umode_t mode;
 218         const char *link;
 219 };
 220 int ovl_create_real(struct inode *dir, struct dentry *newdentry,
 221                     struct cattr *attr,
 222                     struct dentry *hardlink, bool debug);
 223 void ovl_cleanup(struct inode *dir, struct dentry *dentry);
 224
 225 /* copy_up.c */
 226 int ovl_copy_up(struct dentry *dentry);
 227 int ovl_copy_up_flags(struct dentry *dentry, int flags);
 228 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 229 int ovl_set_attr(struct dentry *upper, struct kstat *stat);