/* File: linux/posix_acl.h (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org> */ #ifndef __LINUX_POSIX_ACL_H #define __LINUX_POSIX_ACL_H #include <linux/slab.h> #define ACL_UNDEFINED_ID (-1) /* a_type field in acl_user_posix_entry_t */ #define ACL_TYPE_ACCESS (0x8000) #define ACL_TYPE_DEFAULT (0x4000) /* e_tag entry in struct posix_acl_entry */ #define ACL_USER_OBJ (0x01) #define ACL_USER (0x02) #define ACL_GROUP_OBJ (0x04) #define ACL_GROUP (0x08) #define ACL_MASK (0x10) #define ACL_OTHER (0x20) /* permissions in the e_perm field */ #define ACL_READ (0x04) #define ACL_WRITE (0x02) #define ACL_EXECUTE (0x01) //#define ACL_ADD (0x08) //#define ACL_DELETE (0x10) struct posix_acl_entry { short e_tag; unsigned short e_perm; unsigned int e_id; }; struct posix_acl { atomic_t a_refcount; unsigned int a_count; struct posix_acl_entry a_entries[0]; }; #define FOREACH_ACL_ENTRY(pa, acl, pe) \ for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++) /* * Duplicate an ACL handle. */ static inline struct posix_acl * posix_acl_dup(struct posix_acl *acl) { if (acl) atomic_inc(&acl->a_refcount); return acl; } /* * Free an ACL handle. */ static inline void posix_acl_release(struct posix_acl *acl) { if (acl && atomic_dec_and_test(&acl->a_refcount)) kfree(acl); } /* posix_acl.c */ extern struct posix_acl *posix_acl_alloc(int, gfp_t); extern struct posix_acl *posix_acl_clone(const struct posix_acl *, gfp_t); extern int posix_acl_valid(const struct posix_acl *); extern int posix_acl_permission(struct inode *, const struct posix_acl *, int); extern struct posix_acl *posix_acl_from_mode(mode_t, gfp_t); extern int posix_acl_equiv_mode(const struct posix_acl *, mode_t *); extern int posix_acl_create_masq(struct posix_acl *, mode_t *); extern int posix_acl_chmod_masq(struct posix_acl *, mode_t); extern struct posix_acl *get_posix_acl(struct inode *, int); extern int set_posix_acl(struct inode *, int, struct posix_acl *); #ifdef CONFIG_FS_POSIX_ACL static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) { struct posix_acl **p, *acl; switch (type) { case ACL_TYPE_ACCESS: p = &inode->i_acl; break; case ACL_TYPE_DEFAULT: p = &inode->i_default_acl; break; default: return ERR_PTR(-EINVAL); } acl = ACCESS_ONCE(*p); if (acl) { spin_lock(&inode->i_lock); acl = *p; if (acl != ACL_NOT_CACHED) acl = posix_acl_dup(acl); spin_unlock(&inode->i_lock); } return acl; } static inline int negative_cached_acl(struct inode *inode, int type) { struct posix_acl **p, *acl; switch (type) { case ACL_TYPE_ACCESS: p = &inode->i_acl; break; case ACL_TYPE_DEFAULT: p = &inode->i_default_acl; break; default: BUG(); } acl = ACCESS_ONCE(*p); if (acl) return 0; return 1; } static inline void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) { struct posix_acl *old = NULL; spin_lock(&inode->i_lock); switch (type) { case ACL_TYPE_ACCESS: old = inode->i_acl; inode->i_acl = posix_acl_dup(acl); break; case ACL_TYPE_DEFAULT: old = inode->i_default_acl; inode->i_default_acl = posix_acl_dup(acl); break; } spin_unlock(&inode->i_lock); if (old != ACL_NOT_CACHED) posix_acl_release(old); } static inline void forget_cached_acl(struct inode *inode, int type) { struct posix_acl *old = NULL; spin_lock(&inode->i_lock); switch (type) { case ACL_TYPE_ACCESS: old = inode->i_acl; inode->i_acl = ACL_NOT_CACHED; break; case ACL_TYPE_DEFAULT: old = inode->i_default_acl; inode->i_default_acl = ACL_NOT_CACHED; break; } spin_unlock(&inode->i_lock); if (old != ACL_NOT_CACHED) posix_acl_release(old); } static inline void forget_all_cached_acls(struct inode *inode) { struct posix_acl *old_access, *old_default; spin_lock(&inode->i_lock); old_access = inode->i_acl; old_default = inode->i_default_acl; inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; spin_unlock(&inode->i_lock); if (old_access != ACL_NOT_CACHED) posix_acl_release(old_access); if (old_default != ACL_NOT_CACHED) posix_acl_release(old_default); } #endif static inline void cache_no_acl(struct inode *inode) { #ifdef CONFIG_FS_POSIX_ACL inode->i_acl = NULL; inode->i_default_acl = NULL; #endif } #endif /* __LINUX_POSIX_ACL_H */