fs/aufs/dirren.h

   1 /*
   2  * Copyright (C) 2017 Junjiro R. Okajima
   3  *
   4  * This program, aufs is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * renamed dir info
  20  */
  21
  22 #ifndef __AUFS_DIRREN_H__
  23 #define __AUFS_DIRREN_H__
  24
  25 #ifdef __KERNEL__
  26
  27 #include <linux/dcache.h>
  28 #include <linux/statfs.h>
  29 #include <linux/uuid.h>
  30 #include "hbl.h"
  31
  32 #define AuDirren_NHASH 100
  33
  34 #ifdef CONFIG_AUFS_DIRREN
  35 enum au_brid_type {
  36         AuBrid_Unset,
  37         AuBrid_UUID,
  38         AuBrid_FSID,
  39         AuBrid_DEV
  40 };
  41
  42 struct au_dr_brid {
  43         enum au_brid_type       type;
  44         union {
  45                 uuid_t  uuid;   /* unimplemented yet */
  46                 fsid_t  fsid;
  47                 dev_t   dev;
  48         };
  49 };
  50
  51 /* 20 is the max digits length of ulong 64 */
  52 /* brid-type "_" uuid "_" inum */
  53 #define AUFS_DIRREN_FNAME_SZ    (1 + 1 + UUID_STRING_LEN + 20)
  54 #define AUFS_DIRREN_ENV_VAL_SZ  (AUFS_DIRREN_FNAME_SZ + 1 + 20)
  55
  56 struct au_dr_hino {
  57         struct hlist_bl_node    dr_hnode;
  58         ino_t                   dr_h_ino;
  59 };
  60
  61 struct au_dr_br {
  62         struct hlist_bl_head    dr_h_ino[AuDirren_NHASH];
  63         struct au_dr_brid       dr_brid;
  64 };
  65
  66 struct au_dr_lookup {
  67         /* dr_name is pointed by struct au_do_lookup_args.name */
  68         struct qstr             dr_name; /* subset of dr_info */
  69         aufs_bindex_t           ninfo;
  70         struct au_drinfo        **drinfo;
  71 };
  72 #else
  73 struct au_dr_hino;
  74 /* empty */
  75 struct au_dr_br { };
  76 struct au_dr_lookup { };
  77 #endif
  78
  79 /* ---------------------------------------------------------------------- */
  80
  81 struct au_branch;
  82 struct au_do_lookup_args;
  83 struct au_hinode;
  84 #ifdef CONFIG_AUFS_DIRREN
  85 int au_dr_hino_test_add(struct au_dr_br *dr, ino_t h_ino,
  86                         struct au_dr_hino *add_ent);
  87 void au_dr_hino_free(struct au_dr_br *dr);
  88 int au_dr_br_init(struct super_block *sb, struct au_branch *br,
  89                   const struct path *path);
  90 int au_dr_br_fin(struct super_block *sb, struct au_branch *br);
  91 int au_dr_rename(struct dentry *src, aufs_bindex_t bindex,
  92                  struct qstr *dst_name, void *_rev);
  93 void au_dr_rename_fin(struct dentry *src, aufs_bindex_t btgt, void *rev);
  94 void au_dr_rename_rev(struct dentry *src, aufs_bindex_t bindex, void *rev);
  95 int au_dr_lkup(struct au_do_lookup_args *lkup, struct dentry *dentry,
  96                aufs_bindex_t bindex);
  97 int au_dr_lkup_name(struct au_do_lookup_args *lkup, aufs_bindex_t btgt);
  98 int au_dr_lkup_h_ino(struct au_do_lookup_args *lkup, aufs_bindex_t bindex,
  99                      ino_t h_ino);
 100 void au_dr_lkup_fin(struct au_do_lookup_args *lkup);
 101 int au_dr_opt_set(struct super_block *sb);
 102 int au_dr_opt_flush(struct super_block *sb);
 103 int au_dr_opt_clr(struct super_block *sb, int no_flush);
 104 #else
 105 AuStubInt0(au_dr_hino_test_add, struct au_dr_br *dr, ino_t h_ino,
 106            struct au_dr_hino *add_ent);
 107 AuStubVoid(au_dr_hino_free, struct au_dr_br *dr);
 108 AuStubInt0(au_dr_br_init, struct super_block *sb, struct au_branch *br,
 109            const struct path *path);
 110 AuStubInt0(au_dr_br_fin, struct super_block *sb, struct au_branch *br);
 111 AuStubInt0(au_dr_rename, struct dentry *src, aufs_bindex_t bindex,
 112            struct qstr *dst_name, void *_rev);
 113 AuStubVoid(au_dr_rename_fin, struct dentry *src, aufs_bindex_t btgt, void *rev);
 114 AuStubVoid(au_dr_rename_rev, struct dentry *src, aufs_bindex_t bindex,
 115            void *rev);
 116 AuStubInt0(au_dr_lkup, struct au_do_lookup_args *lkup, struct dentry *dentry,
 117            aufs_bindex_t bindex);
 118 AuStubInt0(au_dr_lkup_name, struct au_do_lookup_args *lkup, aufs_bindex_t btgt);
 119 AuStubInt0(au_dr_lkup_h_ino, struct au_do_lookup_args *lkup,
 120            aufs_bindex_t bindex, ino_t h_ino);
 121 AuStubVoid(au_dr_lkup_fin, struct au_do_lookup_args *lkup);
 122 AuStubInt0(au_dr_opt_set, struct super_block *sb);
 123 AuStubInt0(au_dr_opt_flush, struct super_block *sb);
 124 AuStubInt0(au_dr_opt_clr, struct super_block *sb, int no_flush);
 125 #endif
 126
 127 /* ---------------------------------------------------------------------- */
 128
 129 #ifdef CONFIG_AUFS_DIRREN
 130 static inline int au_dr_ihash(ino_t h_ino)
 131 {
 132         return h_ino % AuDirren_NHASH;
 133 }
 134 #else
 135 AuStubInt0(au_dr_ihash, ino_t h_ino);
 136 #endif
 137
 138 #endif /* __KERNEL__ */
 139 #endif /* __AUFS_DIRREN_H__ */