diff options
Diffstat (limited to 'include/linux/posix_acl.h')
| -rw-r--r-- | include/linux/posix_acl.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h new file mode 100644 index 00000000..54211c1c --- /dev/null +++ b/include/linux/posix_acl.h @@ -0,0 +1,194 @@ +/* + 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 void posix_acl_init(struct posix_acl *, int); +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 */ |