fs/hfsplus/posix_acl.c

   1 /*
   2  * linux/fs/hfsplus/posix_acl.c
   3  *
   4  * Vyacheslav Dubeyko <slava@dubeyko.com>
   5  *
   6  * Handler for Posix Access Control Lists (ACLs) support.
   7  */
   8
   9 #include "hfsplus_fs.h"
  10 #include "xattr.h"
  11 #include "acl.h"
  12
  13 struct posix_acl *hfsplus_get_posix_acl(struct inode *inode, int type)
  14 {
  15         struct posix_acl *acl;
  16         char *xattr_name;
  17         char *value = NULL;
  18         ssize_t size;
  19
  20         hfs_dbg(ACL_MOD, "[%s]: ino %lu\n", __func__, inode->i_ino);
  21
  22         switch (type) {
  23         case ACL_TYPE_ACCESS:
  24                 xattr_name = POSIX_ACL_XATTR_ACCESS;
  25                 break;
  26         case ACL_TYPE_DEFAULT:
  27                 xattr_name = POSIX_ACL_XATTR_DEFAULT;
  28                 break;
  29         default:
  30                 return ERR_PTR(-EINVAL);
  31         }
  32
  33         size = __hfsplus_getxattr(inode, xattr_name, NULL, 0);
  34
  35         if (size > 0) {
  36                 value = (char *)hfsplus_alloc_attr_entry();
  37                 if (unlikely(!value))
  38                         return ERR_PTR(-ENOMEM);
  39                 size = __hfsplus_getxattr(inode, xattr_name, value, size);
  40         }
  41
  42         if (size > 0)
  43                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
  44         else if (size == -ENODATA)
  45                 acl = NULL;
  46         else
  47                 acl = ERR_PTR(size);
  48
  49         hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
  50
  51         if (!IS_ERR(acl))
  52                 set_cached_acl(inode, type, acl);
  53
  54         return acl;
  55 }
  56
  57 int hfsplus_set_posix_acl(struct inode *inode, struct posix_acl *acl,
  58                 int type)
  59 {
  60         int err;
  61         char *xattr_name;
  62         size_t size = 0;
  63         char *value = NULL;
  64
  65         hfs_dbg(ACL_MOD, "[%s]: ino %lu\n", __func__, inode->i_ino);
  66
  67         switch (type) {
  68         case ACL_TYPE_ACCESS:
  69                 xattr_name = POSIX_ACL_XATTR_ACCESS;
  70                 if (acl) {
  71                         err = posix_acl_equiv_mode(acl, &inode->i_mode);
  72                         if (err < 0)
  73                                 return err;
  74                 }
  75                 err = 0;
  76                 break;
  77
  78         case ACL_TYPE_DEFAULT:
  79                 xattr_name = POSIX_ACL_XATTR_DEFAULT;
  80                 if (!S_ISDIR(inode->i_mode))
  81                         return acl ? -EACCES : 0;
  82                 break;
  83
  84         default:
  85                 return -EINVAL;
  86         }
  87
  88         if (acl) {
  89                 size = posix_acl_xattr_size(acl->a_count);
  90                 if (unlikely(size > HFSPLUS_MAX_INLINE_DATA_SIZE))
  91                         return -ENOMEM;
  92                 value = (char *)hfsplus_alloc_attr_entry();
  93                 if (unlikely(!value))
  94                         return -ENOMEM;
  95                 err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
  96                 if (unlikely(err < 0))
  97                         goto end_set_acl;
  98         }
  99
 100         err = __hfsplus_setxattr(inode, xattr_name, value, size, 0);
 101
 102 end_set_acl:
 103         hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
 104
 105         if (!err)
 106                 set_cached_acl(inode, type, acl);
 107
 108         return err;
 109 }
 110
 111 int hfsplus_init_posix_acl(struct inode *inode, struct inode *dir)
 112 {
 113         int err = 0;
 114         struct posix_acl *default_acl, *acl;
 115
 116         hfs_dbg(ACL_MOD,
 117                 "[%s]: ino %lu, dir->ino %lu\n",
 118                 __func__, inode->i_ino, dir->i_ino);
 119
 120         if (S_ISLNK(inode->i_mode))
 121                 return 0;
 122
 123         err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
 124         if (err)
 125                 return err;
 126
 127         if (default_acl) {
 128                 err = hfsplus_set_posix_acl(inode, default_acl,
 129                                             ACL_TYPE_DEFAULT);
 130                 posix_acl_release(default_acl);
 131         }
 132
 133         if (acl) {
 134                 if (!err)
 135                         err = hfsplus_set_posix_acl(inode, acl,
 136                                                     ACL_TYPE_ACCESS);
 137                 posix_acl_release(acl);
 138         }
 139         return err;
 140 }