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/*
* Copyright (C) 2005-2012 Junjiro R. Okajima
*
* This program, aufs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* branch filesystems and xino for them
*/
#ifndef __AUFS_BRANCH_H__
#define __AUFS_BRANCH_H__
#ifdef __KERNEL__
#include <linux/mount.h>
#include "dynop.h"
#include "rwsem.h"
#include "super.h"
/* ---------------------------------------------------------------------- */
/* a xino file */
struct au_xino_file {
struct file *xi_file;
struct mutex xi_nondir_mtx;
/* todo: make xino files an array to support huge inode number */
#ifdef CONFIG_DEBUG_FS
struct dentry *xi_dbgaufs;
#endif
};
/* members for writable branch only */
enum {AuBrWh_BASE, AuBrWh_PLINK, AuBrWh_ORPH, AuBrWh_Last};
struct au_wbr {
struct au_rwsem wbr_wh_rwsem;
struct dentry *wbr_wh[AuBrWh_Last];
atomic_t wbr_wh_running;
#define wbr_whbase wbr_wh[AuBrWh_BASE] /* whiteout base */
#define wbr_plink wbr_wh[AuBrWh_PLINK] /* pseudo-link dir */
#define wbr_orph wbr_wh[AuBrWh_ORPH] /* dir for orphans */
/* mfs mode */
unsigned long long wbr_bytes;
};
/* ext2 has 3 types of operations at least, ext3 has 4 */
#define AuBrDynOp (AuDyLast * 4)
/* protected by superblock rwsem */
struct au_branch {
struct au_xino_file br_xino;
aufs_bindex_t br_id;
int br_perm;
struct vfsmount *br_mnt;
spinlock_t br_dykey_lock;
struct au_dykey *br_dykey[AuBrDynOp];
atomic_t br_count;
struct au_wbr *br_wbr;
/* xino truncation */
blkcnt_t br_xino_upper; /* watermark in blocks */
atomic_t br_xino_running;
#ifdef CONFIG_AUFS_HFSNOTIFY
struct fsnotify_group *br_hfsn_group;
struct fsnotify_ops br_hfsn_ops;
#endif
#ifdef CONFIG_SYSFS
/* an entry under sysfs per mount-point */
char br_name[8];
struct attribute br_attr;
#endif
};
/* ---------------------------------------------------------------------- */
/* branch permissions and attributes */
#define AuBrPerm_RW 1 /* writable, hardlinkable wh */
#define AuBrPerm_RO (1 << 1) /* readonly */
#define AuBrPerm_RR (1 << 2) /* natively readonly */
#define AuBrPerm_Mask (AuBrPerm_RW | AuBrPerm_RO | AuBrPerm_RR)
#define AuBrRAttr_WH (1 << 3) /* whiteout-able */
#define AuBrWAttr_NoLinkWH (1 << 4) /* un-hardlinkable whiteouts */
static inline int au_br_writable(int brperm)
{
return brperm & AuBrPerm_RW;
}
static inline int au_br_whable(int brperm)
{
return brperm & (AuBrPerm_RW | AuBrRAttr_WH);
}
static inline int au_br_wh_linkable(int brperm)
{
return !(brperm & AuBrWAttr_NoLinkWH);
}
static inline int au_br_rdonly(struct au_branch *br)
{
return ((br->br_mnt->mnt_sb->s_flags & MS_RDONLY)
|| !au_br_writable(br->br_perm))
? -EROFS : 0;
}
static inline int au_br_hnotifyable(int brperm __maybe_unused)
{
#ifdef CONFIG_AUFS_HNOTIFY
return !(brperm & AuBrPerm_RR);
#else
return 0;
#endif
}
/* ---------------------------------------------------------------------- */
/* branch.c */
struct au_sbinfo;
void au_br_free(struct au_sbinfo *sinfo);
int au_br_index(struct super_block *sb, aufs_bindex_t br_id);
struct au_opt_add;
int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount);
struct au_opt_del;
int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount);
long au_ibusy_ioctl(struct file *file, unsigned long arg);
#ifdef CONFIG_COMPAT
long au_ibusy_compat_ioctl(struct file *file, unsigned long arg);
#endif
struct au_opt_mod;
int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
int *do_refresh);
/* xino.c */
static const loff_t au_loff_max = LLONG_MAX;
int au_xib_trunc(struct super_block *sb);
ssize_t xino_fread(au_readf_t func, struct file *file, void *buf, size_t size,
loff_t *pos);
ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
loff_t *pos);
struct file *au_xino_create2(struct file *base_file, struct file *copy_src);
struct file *au_xino_create(struct super_block *sb, char *fname, int silent);
ino_t au_xino_new_ino(struct super_block *sb);
void au_xino_delete_inode(struct inode *inode, const int unlinked);
int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
ino_t ino);
int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
ino_t *ino);
int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t hino,
struct file *base_file, int do_test);
int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex);
struct au_opt_xino;
int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount);
void au_xino_clr(struct super_block *sb);
struct file *au_xino_def(struct super_block *sb);
int au_xino_path(struct seq_file *seq, struct file *file);
/* ---------------------------------------------------------------------- */
/* Superblock to branch */
static inline
aufs_bindex_t au_sbr_id(struct super_block *sb, aufs_bindex_t bindex)
{
return au_sbr(sb, bindex)->br_id;
}
static inline
struct vfsmount *au_sbr_mnt(struct super_block *sb, aufs_bindex_t bindex)
{
return au_sbr(sb, bindex)->br_mnt;
}
static inline
struct super_block *au_sbr_sb(struct super_block *sb, aufs_bindex_t bindex)
{
return au_sbr_mnt(sb, bindex)->mnt_sb;
}
static inline void au_sbr_put(struct super_block *sb, aufs_bindex_t bindex)
{
atomic_dec(&au_sbr(sb, bindex)->br_count);
}
static inline int au_sbr_perm(struct super_block *sb, aufs_bindex_t bindex)
{
return au_sbr(sb, bindex)->br_perm;
}
static inline int au_sbr_whable(struct super_block *sb, aufs_bindex_t bindex)
{
return au_br_whable(au_sbr_perm(sb, bindex));
}
/* ---------------------------------------------------------------------- */
/*
* wbr_wh_read_lock, wbr_wh_write_lock
* wbr_wh_read_unlock, wbr_wh_write_unlock, wbr_wh_downgrade_lock
*/
AuSimpleRwsemFuncs(wbr_wh, struct au_wbr *wbr, &wbr->wbr_wh_rwsem);
#define WbrWhMustNoWaiters(wbr) AuRwMustNoWaiters(&wbr->wbr_wh_rwsem)
#define WbrWhMustAnyLock(wbr) AuRwMustAnyLock(&wbr->wbr_wh_rwsem)
#define WbrWhMustWriteLock(wbr) AuRwMustWriteLock(&wbr->wbr_wh_rwsem)
#endif /* __KERNEL__ */
#endif /* __AUFS_BRANCH_H__ */
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