fs/aufs/dirren.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2017-2020 Junjiro R. Okajima
   4  *
   5  * This program, aufs is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /*
  20  * renamed dir info
  21  */
  22
  23 #ifndef __AUFS_DIRREN_H__
  24 #define __AUFS_DIRREN_H__
  25
  26 #ifdef __KERNEL__
  27
  28 #include <linux/dcache.h>
  29 #include <linux/statfs.h>
  30 #include <linux/uuid.h>
  31 #include "hbl.h"
  32
  33 #define AuDirren_NHASH 100
  34
  35 #ifdef CONFIG_AUFS_DIRREN
  36 enum au_brid_type {
  37         AuBrid_Unset,
  38         AuBrid_UUID,
  39         AuBrid_FSID,
  40         AuBrid_DEV
  41 };
  42
  43 struct au_dr_brid {
  44         enum au_brid_type       type;
  45         union {
  46                 uuid_t  uuid;   /* unimplemented yet */
  47                 fsid_t  fsid;
  48                 dev_t   dev;
  49         };
  50 };
  51
  52 /* 20 is the max digits length of ulong 64 */
  53 /* brid-type "_" uuid "_" inum */
  54 #define AUFS_DIRREN_FNAME_SZ    (1 + 1 + UUID_STRING_LEN + 20)
  55 #define AUFS_DIRREN_ENV_VAL_SZ  (AUFS_DIRREN_FNAME_SZ + 1 + 20)
  56
  57 struct au_dr_hino {
  58         struct hlist_bl_node    dr_hnode;
  59         ino_t                   dr_h_ino;
  60 };
  61
  62 struct au_dr_br {
  63         struct hlist_bl_head    dr_h_ino[AuDirren_NHASH];
  64         struct au_dr_brid       dr_brid;
  65 };
  66
  67 struct au_dr_lookup {
  68         /* dr_name is pointed by struct au_do_lookup_args.name */
  69         struct qstr             dr_name; /* subset of dr_info */
  70         aufs_bindex_t           ninfo;
  71         struct au_drinfo        **drinfo;
  72 };
  73 #else
  74 struct au_dr_hino;
  75 /* empty */
  76 struct au_dr_br { };
  77 struct au_dr_lookup { };
  78 #endif
  79
  80 /* ---------------------------------------------------------------------- */
  81
  82 struct au_branch;
  83 struct au_do_lookup_args;
  84 struct au_hinode;
  85 #ifdef CONFIG_AUFS_DIRREN
  86 int au_dr_hino_test_add(struct au_dr_br *dr, ino_t h_ino,
  87                         struct au_dr_hino *add_ent);
  88 void au_dr_hino_free(struct au_dr_br *dr);
  89 int au_dr_br_init(struct super_block *sb, struct au_branch *br,
  90                   const struct path *path);
  91 int au_dr_br_fin(struct super_block *sb, struct au_branch *br);
  92 int au_dr_rename(struct dentry *src, aufs_bindex_t bindex,
  93                  struct qstr *dst_name, void *_rev);
  94 void au_dr_rename_fin(struct dentry *src, aufs_bindex_t btgt, void *rev);
  95 void au_dr_rename_rev(struct dentry *src, aufs_bindex_t bindex, void *rev);
  96 int au_dr_lkup(struct au_do_lookup_args *lkup, struct dentry *dentry,
  97                aufs_bindex_t bindex);
  98 int au_dr_lkup_name(struct au_do_lookup_args *lkup, aufs_bindex_t btgt);
  99 int au_dr_lkup_h_ino(struct au_do_lookup_args *lkup, aufs_bindex_t bindex,
 100                      ino_t h_ino);
 101 void au_dr_lkup_fin(struct au_do_lookup_args *lkup);
 102 int au_dr_opt_set(struct super_block *sb);
 103 int au_dr_opt_flush(struct super_block *sb);
 104 int au_dr_opt_clr(struct super_block *sb, int no_flush);
 105 #else
 106 AuStubInt0(au_dr_hino_test_add, struct au_dr_br *dr, ino_t h_ino,
 107            struct au_dr_hino *add_ent);
 108 AuStubVoid(au_dr_hino_free, struct au_dr_br *dr);
 109 AuStubInt0(au_dr_br_init, struct super_block *sb, struct au_branch *br,
 110            const struct path *path);
 111 AuStubInt0(au_dr_br_fin, struct super_block *sb, struct au_branch *br);
 112 AuStubInt0(au_dr_rename, struct dentry *src, aufs_bindex_t bindex,
 113            struct qstr *dst_name, void *_rev);
 114 AuStubVoid(au_dr_rename_fin, struct dentry *src, aufs_bindex_t btgt, void *rev);
 115 AuStubVoid(au_dr_rename_rev, struct dentry *src, aufs_bindex_t bindex,
 116            void *rev);
 117 AuStubInt0(au_dr_lkup, struct au_do_lookup_args *lkup, struct dentry *dentry,
 118            aufs_bindex_t bindex);
 119 AuStubInt0(au_dr_lkup_name, struct au_do_lookup_args *lkup, aufs_bindex_t btgt);
 120 AuStubInt0(au_dr_lkup_h_ino, struct au_do_lookup_args *lkup,
 121            aufs_bindex_t bindex, ino_t h_ino);
 122 AuStubVoid(au_dr_lkup_fin, struct au_do_lookup_args *lkup);
 123 AuStubInt0(au_dr_opt_set, struct super_block *sb);
 124 AuStubInt0(au_dr_opt_flush, struct super_block *sb);
 125 AuStubInt0(au_dr_opt_clr, struct super_block *sb, int no_flush);
 126 #endif
 127
 128 /* ---------------------------------------------------------------------- */
 129
 130 #ifdef CONFIG_AUFS_DIRREN
 131 static inline int au_dr_ihash(ino_t h_ino)
 132 {
 133         return h_ino % AuDirren_NHASH;
 134 }
 135 #else
 136 AuStubInt0(au_dr_ihash, ino_t h_ino);
 137 #endif
 138
 139 #endif /* __KERNEL__ */
 140 #endif /* __AUFS_DIRREN_H__ */