/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2005-2019 Junjiro R. Okajima */ /* * branch filesystems and xino for them */ #ifndef __AUFS_BRANCH_H__ #define __AUFS_BRANCH_H__ #ifdef __KERNEL__ #include #include "lcnt.h" #include "rwsem.h" #include "super.h" /* ---------------------------------------------------------------------- */ /* a xino file */ struct au_xino { struct file **xi_file; unsigned int xi_nfile; struct { spinlock_t spin; ino_t *array; int total; /* reserved for future use */ /* unsigned long *bitmap; */ wait_queue_head_t wqh; } xi_nondir; struct mutex xi_mtx; /* protects xi_file array */ struct hlist_bl_head xi_writing; atomic_t xi_truncating; struct kref xi_kref; }; /* 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 */ }; /* 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 *br_xino; aufs_bindex_t br_id; int br_perm; struct path br_path; au_lcnt_t br_count; /* in-use for other */ struct au_wbr *br_wbr; #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 void au_xino_get(struct au_branch *br) { struct au_xino *xi; xi = br->br_xino; if (xi) kref_get(&xi->xi_kref); } static inline int au_xino_count(struct au_branch *br) { int v; struct au_xino *xi; v = 0; xi = br->br_xino; if (xi) v = kref_read(&xi->xi_kref); return v; } /* ---------------------------------------------------------------------- */ /* 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); /* xino.c */ aufs_bindex_t au_xi_root(struct super_block *sb, struct dentry *dentry); struct file *au_xino_create(struct super_block *sb, char *fpath, int silent); struct file *au_xino_create2(struct super_block *sb, struct path *base, struct file *copy_src); struct au_xi_new { struct au_xino *xi; /* switch between xino and xigen */ int idx; struct path *base; struct file *copy_src; }; struct file *au_xi_new(struct super_block *sb, struct au_xi_new *xinew); int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino, ino_t *ino); int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino, ino_t ino); 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); int au_xib_trunc(struct super_block *sb); int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex, int idx_begin); struct au_xino *au_xino_alloc(unsigned int nfile); int au_xino_put(struct au_branch *br); struct file *au_xino_file1(struct au_xino *xi); struct au_opt_xino; void au_xino_clr(struct super_block *sb); int au_xino_set(struct super_block *sb, struct au_opt_xino *xiopt); struct file *au_xino_def(struct super_block *sb); int au_xino_init_br(struct super_block *sb, struct au_branch *br, ino_t hino, struct path *base); ino_t au_xino_new_ino(struct super_block *sb); void au_xino_delete_inode(struct inode *inode, const int unlinked); int au_xino_path(struct seq_file *seq, struct file *file); /* ---------------------------------------------------------------------- */ /* @idx is signed to accept -1 meaning the first file */ static inline struct file *au_xino_file(struct au_xino *xi, int idx) { struct file *file; file = NULL; if (!xi) goto out; if (idx >= 0) { if (idx < xi->xi_nfile) file = xi->xi_file[idx]; } else file = au_xino_file1(xi); out: return 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 super_block *au_sbr_sb(struct super_block *sb, aufs_bindex_t bindex) { return au_br_sb(au_sbr(sb, bindex)); } 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)); } /* ---------------------------------------------------------------------- */ #define wbr_wh_read_lock(wbr) au_rw_read_lock(&(wbr)->wbr_wh_rwsem) #define wbr_wh_write_lock(wbr) au_rw_write_lock(&(wbr)->wbr_wh_rwsem) #define wbr_wh_read_trylock(wbr) au_rw_read_trylock(&(wbr)->wbr_wh_rwsem) #define wbr_wh_write_trylock(wbr) au_rw_write_trylock(&(wbr)->wbr_wh_rwsem) /* #define wbr_wh_read_trylock_nested(wbr) \ au_rw_read_trylock_nested(&(wbr)->wbr_wh_rwsem) #define wbr_wh_write_trylock_nested(wbr) \ au_rw_write_trylock_nested(&(wbr)->wbr_wh_rwsem) */ #define wbr_wh_read_unlock(wbr) au_rw_read_unlock(&(wbr)->wbr_wh_rwsem) #define wbr_wh_write_unlock(wbr) au_rw_write_unlock(&(wbr)->wbr_wh_rwsem) #define wbr_wh_downgrade_lock(wbr) au_rw_dgrade_lock(&(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__ */