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 struct ovl_entry;
  13
  14 enum ovl_path_type {
  15         __OVL_PATH_PURE         = (1 << 0),
  16         __OVL_PATH_UPPER        = (1 << 1),
  17         __OVL_PATH_MERGE        = (1 << 2),
  18 };
  19
  20 #define OVL_TYPE_UPPER(type)    ((type) & __OVL_PATH_UPPER)
  21 #define OVL_TYPE_MERGE(type)    ((type) & __OVL_PATH_MERGE)
  22 #define OVL_TYPE_PURE_UPPER(type) ((type) & __OVL_PATH_PURE)
  23 #define OVL_TYPE_MERGE_OR_LOWER(type) \
  24         (OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type))
  25
  26
  27 #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
  28 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
  29
  30 #define OVL_ISUPPER_MASK 1UL
  31
  32 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
  33 {
  34         int err = vfs_rmdir(dir, dentry);
  35         pr_debug("rmdir(%pd2) = %i\n", dentry, err);
  36         return err;
  37 }
  38
  39 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
  40 {
  41         int err = vfs_unlink(dir, dentry, NULL);
  42         pr_debug("unlink(%pd2) = %i\n", dentry, err);
  43         return err;
  44 }
  45
  46 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
  47                               struct dentry *new_dentry, bool debug)
  48 {
  49         int err = vfs_link(old_dentry, dir, new_dentry, NULL);
  50         if (debug) {
  51                 pr_debug("link(%pd2, %pd2) = %i\n",
  52                          old_dentry, new_dentry, err);
  53         }
  54         return err;
  55 }
  56
  57 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
  58                              umode_t mode, bool debug)
  59 {
  60         int err = vfs_create(dir, dentry, mode, true);
  61         if (debug)
  62                 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
  63         return err;
  64 }
  65
  66 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
  67                                umode_t mode, bool debug)
  68 {
  69         int err = vfs_mkdir(dir, dentry, mode);
  70         if (debug)
  71                 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
  72         return err;
  73 }
  74
  75 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
  76                                umode_t mode, dev_t dev, bool debug)
  77 {
  78         int err = vfs_mknod(dir, dentry, mode, dev);
  79         if (debug) {
  80                 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
  81                          dentry, mode, dev, err);
  82         }
  83         return err;
  84 }
  85
  86 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
  87                                  const char *oldname, bool debug)
  88 {
  89         int err = vfs_symlink(dir, dentry, oldname);
  90         if (debug)
  91                 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
  92         return err;
  93 }
  94
  95 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
  96                                   const void *value, size_t size, int flags)
  97 {
  98         int err = vfs_setxattr(dentry, name, value, size, flags);
  99         pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
 100                  dentry, name, (int) size, (char *) value, flags, err);
 101         return err;
 102 }
 103
 104 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
 105 {
 106         int err = vfs_removexattr(dentry, name);
 107         pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
 108         return err;
 109 }
 110
 111 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
 112                                 struct inode *newdir, struct dentry *newdentry,
 113                                 unsigned int flags)
 114 {
 115         int err;
 116
 117         pr_debug("rename(%pd2, %pd2, 0x%x)\n",
 118                  olddentry, newdentry, flags);
 119
 120         err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
 121
 122         if (err) {
 123                 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
 124                          olddentry, newdentry, err);
 125         }
 126         return err;
 127 }
 128
 129 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
 130 {
 131         int err = vfs_whiteout(dir, dentry);
 132         pr_debug("whiteout(%pd2) = %i\n", dentry, err);
 133         return err;
 134 }
 135
 136 static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)
 137 {
 138         unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
 139
 140         if (is_upper)
 141                 *is_upper = x & OVL_ISUPPER_MASK;
 142
 143         return (struct inode *) (x & ~OVL_ISUPPER_MASK);
 144 }
 145
 146 enum ovl_path_type ovl_path_type(struct dentry *dentry);
 147 u64 ovl_dentry_version_get(struct dentry *dentry);
 148 void ovl_dentry_version_inc(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 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
 153 struct dentry *ovl_dentry_upper(struct dentry *dentry);
 154 struct dentry *ovl_dentry_lower(struct dentry *dentry);
 155 struct dentry *ovl_dentry_real(struct dentry *dentry);
 156 struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode,
 157                                     bool is_upper);
 158 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
 159 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
 160 struct dentry *ovl_workdir(struct dentry *dentry);
 161 int ovl_want_write(struct dentry *dentry);
 162 void ovl_drop_write(struct dentry *dentry);
 163 bool ovl_dentry_is_opaque(struct dentry *dentry);
 164 void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
 165 bool ovl_is_whiteout(struct dentry *dentry);
 166 const struct cred *ovl_override_creds(struct super_block *sb);
 167 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
 168 void ovl_inode_update(struct inode *inode, struct inode *upperinode);
 169 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 170                           unsigned int flags);
 171 struct file *ovl_path_open(struct path *path, int flags);
 172
 173 struct dentry *ovl_upper_create(struct dentry *upperdir, struct dentry *dentry,
 174                                 struct kstat *stat, const char *link);
 175
 176 /* readdir.c */
 177 extern const struct file_operations ovl_dir_operations;
 178 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
 179 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
 180 void ovl_cache_free(struct list_head *list);
 181 int ovl_check_d_type_supported(struct path *realpath);
 182 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 183                          struct dentry *dentry, int level);
 184
 185 /* inode.c */
 186 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
 187 int ovl_permission(struct inode *inode, int mask);
 188 int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
 189                   size_t size, int flags);
 190 int ovl_xattr_get(struct dentry *dentry, const char *name,
 191                   void *value, size_t size);
 192 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 193 struct posix_acl *ovl_get_acl(struct inode *inode, int type);
 194 int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
 195 int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
 196 bool ovl_is_private_xattr(const char *name);
 197
 198 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode);
 199 struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode);
 200 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 201 {
 202         to->i_uid = from->i_uid;
 203         to->i_gid = from->i_gid;
 204         to->i_mode = from->i_mode;
 205         to->i_atime = from->i_atime;
 206         to->i_mtime = from->i_mtime;
 207         to->i_ctime = from->i_ctime;
 208 }
 209
 210 /* dir.c */
 211 extern const struct inode_operations ovl_dir_inode_operations;
 212 struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
 213 int ovl_create_real(struct inode *dir, struct dentry *newdentry,
 214                     struct kstat *stat, const char *link,
 215                     struct dentry *hardlink, bool debug);
 216 void ovl_cleanup(struct inode *dir, struct dentry *dentry);
 217
 218 /* copy_up.c */
 219 int ovl_copy_up(struct dentry *dentry);
 220 int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
 221                     struct path *lowerpath, struct kstat *stat);
 222 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 223 int ovl_set_attr(struct dentry *upper, struct kstat *stat);