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