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