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/*
* Copyright (C) 2005-2015 Junjiro R. Okajima
*/
/*
* 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
};
/* File-based Hierarchical Storage Management */
struct au_br_fhsm {
#ifdef CONFIG_AUFS_FHSM
struct mutex bf_lock;
unsigned long bf_jiffy;
struct aufs_stfs bf_stfs;
int bf_readable;
#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)
#ifdef CONFIG_AUFS_HFSNOTIFY
/* support for asynchronous destruction */
struct au_br_hfsnotify {
struct fsnotify_group *hfsn_group;
};
#endif
/* sysfs entries */
struct au_brsysfs {
char name[16];
struct attribute attr;
};
enum {
AuBrSysfs_BR,
AuBrSysfs_BRID,
AuBrSysfs_Last
};
/* protected by superblock rwsem */
struct au_branch {
struct au_xino_file br_xino;
aufs_bindex_t br_id;
int br_perm;
struct path br_path;
spinlock_t br_dykey_lock;
struct au_dykey *br_dykey[AuBrDynOp];
atomic_t br_count;
struct au_wbr *br_wbr;
struct au_br_fhsm *br_fhsm;
/* xino truncation */
atomic_t br_xino_running;
#ifdef CONFIG_AUFS_HFSNOTIFY
struct au_br_hfsnotify *br_hfsn;
#endif
#ifdef CONFIG_SYSFS
/* entries under sysfs per mount-point */
struct au_brsysfs br_sysfs[AuBrSysfs_Last];
#endif
};
/* ---------------------------------------------------------------------- */
static inline struct vfsmount *au_br_mnt(struct au_branch *br)
{
return br->br_path.mnt;
}
static inline struct dentry *au_br_dentry(struct au_branch *br)
{
return br->br_path.dentry;
}
static inline struct super_block *au_br_sb(struct au_branch *br)
{
return au_br_mnt(br)->mnt_sb;
}
static inline int au_br_rdonly(struct au_branch *br)
{
return ((au_br_sb(br)->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
}
static inline int au_br_test_oflag(int oflag, struct au_branch *br)
{
int err, exec_flag;
err = 0;
exec_flag = oflag & __FMODE_EXEC;
if (unlikely(exec_flag && (au_br_mnt(br)->mnt_flags & MNT_NOEXEC)))
err = -EACCES;
return err;
}
/* ---------------------------------------------------------------------- */
/* 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);
struct aufs_stfs;
int au_br_stfs(struct au_branch *br, struct aufs_stfs *stfs);
/* xino.c */
static const loff_t au_loff_max = LLONG_MAX;
int au_xib_trunc(struct super_block *sb);
ssize_t xino_fread(vfs_readf_t func, struct file *file, void *buf, size_t size,
loff_t *pos);
ssize_t xino_fwrite(vfs_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_br_mnt(au_sbr(sb, bindex));
}
static inline
struct super_block *au_sbr_sb(struct super_block *sb, aufs_bindex_t bindex)
{
return au_br_sb(au_sbr(sb, bindex));
}
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)
/* ---------------------------------------------------------------------- */
#ifdef CONFIG_AUFS_FHSM
static inline void au_br_fhsm_init(struct au_br_fhsm *brfhsm)
{
mutex_init(&brfhsm->bf_lock);
brfhsm->bf_jiffy = 0;
brfhsm->bf_readable = 0;
}
static inline void au_br_fhsm_fin(struct au_br_fhsm *brfhsm)
{
mutex_destroy(&brfhsm->bf_lock);
}
#else
AuStubVoid(au_br_fhsm_init, struct au_br_fhsm *brfhsm)
AuStubVoid(au_br_fhsm_fin, struct au_br_fhsm *brfhsm)
#endif
#endif /* __KERNEL__ */
#endif /* __AUFS_BRANCH_H__ */
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