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 #define OVL_XATTR_PRE_NAME "trusted.overlay."
  27 #define OVL_XATTR_PRE_LEN  16
  28 #define OVL_XATTR_OPAQUE   OVL_XATTR_PRE_NAME"opaque"
  29
  30 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
  31 {
  32         int err = vfs_rmdir(dir, dentry);
  33         pr_debug("rmdir(%pd2) = %i\n", dentry, err);
  34         return err;
  35 }
  36
  37 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
  38 {
  39         int err = vfs_unlink(dir, dentry, NULL);
  40         pr_debug("unlink(%pd2) = %i\n", dentry, err);
  41         return err;
  42 }
  43
  44 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
  45                               struct dentry *new_dentry, bool debug)
  46 {
  47         int err = vfs_link(old_dentry, dir, new_dentry, NULL);
  48         if (debug) {
  49                 pr_debug("link(%pd2, %pd2) = %i\n",
  50                          old_dentry, new_dentry, err);
  51         }
  52         return err;
  53 }
  54
  55 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
  56                              umode_t mode, bool debug)
  57 {
  58         int err = vfs_create(dir, dentry, mode, true);
  59         if (debug)
  60                 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
  61         return err;
  62 }
  63
  64 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
  65                                umode_t mode, bool debug)
  66 {
  67         int err = vfs_mkdir(dir, dentry, mode);
  68         if (debug)
  69                 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
  70         return err;
  71 }
  72
  73 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
  74                                umode_t mode, dev_t dev, bool debug)
  75 {
  76         int err = vfs_mknod(dir, dentry, mode, dev);
  77         if (debug) {
  78                 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
  79                          dentry, mode, dev, err);
  80         }
  81         return err;
  82 }
  83
  84 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
  85                                  const char *oldname, bool debug)
  86 {
  87         int err = vfs_symlink(dir, dentry, oldname);
  88         if (debug)
  89                 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
  90         return err;
  91 }
  92
  93 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
  94                                   const void *value, size_t size, int flags)
  95 {
  96         int err = vfs_setxattr(dentry, name, value, size, flags);
  97         pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
  98                  dentry, name, (int) size, (char *) value, flags, err);
  99         return err;
 100 }
 101
 102 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
 103 {
 104         int err = vfs_removexattr(dentry, name);
 105         pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
 106         return err;
 107 }
 108
 109 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
 110                                 struct inode *newdir, struct dentry *newdentry,
 111                                 unsigned int flags)
 112 {
 113         int err;
 114
 115         pr_debug("rename2(%pd2, %pd2, 0x%x)\n",
 116                  olddentry, newdentry, flags);
 117
 118         err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
 119
 120         if (err) {
 121                 pr_debug("...rename2(%pd2, %pd2, ...) = %i\n",
 122                          olddentry, newdentry, err);
 123         }
 124         return err;
 125 }
 126
 127 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
 128 {
 129         int err = vfs_whiteout(dir, dentry);
 130         pr_debug("whiteout(%pd2) = %i\n", dentry, err);
 131         return err;
 132 }
 133
 134 enum ovl_path_type ovl_path_type(struct dentry *dentry);
 135 u64 ovl_dentry_version_get(struct dentry *dentry);
 136 void ovl_dentry_version_inc(struct dentry *dentry);
 137 void ovl_path_upper(struct dentry *dentry, struct path *path);
 138 void ovl_path_lower(struct dentry *dentry, struct path *path);
 139 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
 140 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
 141 struct dentry *ovl_dentry_upper(struct dentry *dentry);
 142 struct dentry *ovl_dentry_lower(struct dentry *dentry);
 143 struct dentry *ovl_dentry_real(struct dentry *dentry);
 144 struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper);
 145 struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode,
 146                                     bool is_upper);
 147 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
 148 bool ovl_is_default_permissions(struct inode *inode);
 149 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
 150 struct dentry *ovl_workdir(struct dentry *dentry);
 151 int ovl_want_write(struct dentry *dentry);
 152 void ovl_drop_write(struct dentry *dentry);
 153 bool ovl_dentry_is_opaque(struct dentry *dentry);
 154 void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
 155 bool ovl_is_whiteout(struct dentry *dentry);
 156 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
 157 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 158                           unsigned int flags);
 159 struct file *ovl_path_open(struct path *path, int flags);
 160
 161 struct dentry *ovl_upper_create(struct dentry *upperdir, struct dentry *dentry,
 162                                 struct kstat *stat, const char *link);
 163
 164 /* readdir.c */
 165 extern const struct file_operations ovl_dir_operations;
 166 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
 167 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
 168 void ovl_cache_free(struct list_head *list);
 169 int ovl_check_d_type_supported(struct path *realpath);
 170
 171 /* inode.c */
 172 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
 173 int ovl_permission(struct inode *inode, int mask);
 174 int ovl_setxattr(struct dentry *dentry, const char *name,
 175                  const void *value, size_t size, int flags);
 176 ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
 177                      const char *name, void *value, size_t size);
 178 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 179 int ovl_removexattr(struct dentry *dentry, const char *name);
 180 struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags);
 181
 182 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
 183                             struct ovl_entry *oe);
 184 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 185 {
 186         to->i_uid = from->i_uid;
 187         to->i_gid = from->i_gid;
 188 }
 189
 190 /* dir.c */
 191 extern const struct inode_operations ovl_dir_inode_operations;
 192 struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
 193 int ovl_create_real(struct inode *dir, struct dentry *newdentry,
 194                     struct kstat *stat, const char *link,
 195                     struct dentry *hardlink, bool debug);
 196 void ovl_cleanup(struct inode *dir, struct dentry *dentry);
 197
 198 /* copy_up.c */
 199 int ovl_copy_up(struct dentry *dentry);
 200 int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
 201                     struct path *lowerpath, struct kstat *stat);
 202 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 203 int ovl_set_attr(struct dentry *upper, struct kstat *stat);