fs/orangefs/acl.c

   1 /*
   2  * (C) 2001 Clemson University and The University of Chicago
   3  *
   4  * See COPYING in top-level directory.
   5  */
   6
   7 #include "protocol.h"
   8 #include "orangefs-kernel.h"
   9 #include "orangefs-bufmap.h"
  10 #include <linux/posix_acl_xattr.h>
  11 #include <linux/fs_struct.h>
  12
  13 struct posix_acl *orangefs_get_acl(struct inode *inode, int type)
  14 {
  15         struct posix_acl *acl;
  16         int ret;
  17         char *key = NULL, *value = NULL;
  18
  19         switch (type) {
  20         case ACL_TYPE_ACCESS:
  21                 key = ORANGEFS_XATTR_NAME_ACL_ACCESS;
  22                 break;
  23         case ACL_TYPE_DEFAULT:
  24                 key = ORANGEFS_XATTR_NAME_ACL_DEFAULT;
  25                 break;
  26         default:
  27                 gossip_err("orangefs_get_acl: bogus value of type %d\n", type);
  28                 return ERR_PTR(-EINVAL);
  29         }
  30         /*
  31          * Rather than incurring a network call just to determine the exact
  32          * length of the attribute, I just allocate a max length to save on
  33          * the network call. Conceivably, we could pass NULL to
  34          * orangefs_inode_getxattr() to probe the length of the value, but
  35          * I don't do that for now.
  36          */
  37         value = kmalloc(ORANGEFS_MAX_XATTR_VALUELEN, GFP_KERNEL);
  38         if (value == NULL)
  39                 return ERR_PTR(-ENOMEM);
  40
  41         gossip_debug(GOSSIP_ACL_DEBUG,
  42                      "inode %pU, key %s, type %d\n",
  43                      get_khandle_from_ino(inode),
  44                      key,
  45                      type);
  46         ret = orangefs_inode_getxattr(inode,
  47                                    "",
  48                                    key,
  49                                    value,
  50                                    ORANGEFS_MAX_XATTR_VALUELEN);
  51         /* if the key exists, convert it to an in-memory rep */
  52         if (ret > 0) {
  53                 acl = posix_acl_from_xattr(&init_user_ns, value, ret);
  54         } else if (ret == -ENODATA || ret == -ENOSYS) {
  55                 acl = NULL;
  56         } else {
  57                 gossip_err("inode %pU retrieving acl's failed with error %d\n",
  58                            get_khandle_from_ino(inode),
  59                            ret);
  60                 acl = ERR_PTR(ret);
  61         }
  62         /* kfree(NULL) is safe, so don't worry if value ever got used */
  63         kfree(value);
  64         return acl;
  65 }
  66
  67 int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
  68 {
  69         struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
  70         int error = 0;
  71         void *value = NULL;
  72         size_t size = 0;
  73         const char *name = NULL;
  74
  75         switch (type) {
  76         case ACL_TYPE_ACCESS:
  77                 name = ORANGEFS_XATTR_NAME_ACL_ACCESS;
  78                 if (acl) {
  79                         umode_t mode = inode->i_mode;
  80                         /*
  81                          * can we represent this with the traditional file
  82                          * mode permission bits?
  83                          */
  84                         error = posix_acl_equiv_mode(acl, &mode);
  85                         if (error < 0) {
  86                                 gossip_err("%s: posix_acl_equiv_mode err: %d\n",
  87                                            __func__,
  88                                            error);
  89                                 return error;
  90                         }
  91
  92                         if (inode->i_mode != mode)
  93                                 SetModeFlag(orangefs_inode);
  94                         inode->i_mode = mode;
  95                         mark_inode_dirty_sync(inode);
  96                         if (error == 0)
  97                                 acl = NULL;
  98                 }
  99                 break;
 100         case ACL_TYPE_DEFAULT:
 101                 name = ORANGEFS_XATTR_NAME_ACL_DEFAULT;
 102                 break;
 103         default:
 104                 gossip_err("%s: invalid type %d!\n", __func__, type);
 105                 return -EINVAL;
 106         }
 107
 108         gossip_debug(GOSSIP_ACL_DEBUG,
 109                      "%s: inode %pU, key %s type %d\n",
 110                      __func__, get_khandle_from_ino(inode),
 111                      name,
 112                      type);
 113
 114         if (acl) {
 115                 size = posix_acl_xattr_size(acl->a_count);
 116                 value = kmalloc(size, GFP_KERNEL);
 117                 if (!value)
 118                         return -ENOMEM;
 119
 120                 error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 121                 if (error < 0)
 122                         goto out;
 123         }
 124
 125         gossip_debug(GOSSIP_ACL_DEBUG,
 126                      "%s: name %s, value %p, size %zd, acl %p\n",
 127                      __func__, name, value, size, acl);
 128         /*
 129          * Go ahead and set the extended attribute now. NOTE: Suppose acl
 130          * was NULL, then value will be NULL and size will be 0 and that
 131          * will xlate to a removexattr. However, we don't want removexattr
 132          * complain if attributes does not exist.
 133          */
 134         error = orangefs_inode_setxattr(inode, "", name, value, size, 0);
 135
 136 out:
 137         kfree(value);
 138         if (!error)
 139                 set_cached_acl(inode, type, acl);
 140         return error;
 141 }
 142
 143 int orangefs_init_acl(struct inode *inode, struct inode *dir)
 144 {
 145         struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
 146         struct posix_acl *default_acl, *acl;
 147         umode_t mode = inode->i_mode;
 148         int error = 0;
 149
 150         ClearModeFlag(orangefs_inode);
 151
 152         error = posix_acl_create(dir, &mode, &default_acl, &acl);
 153         if (error)
 154                 return error;
 155
 156         if (default_acl) {
 157                 error = orangefs_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
 158                 posix_acl_release(default_acl);
 159         }
 160
 161         if (acl) {
 162                 if (!error)
 163                         error = orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
 164                 posix_acl_release(acl);
 165         }
 166
 167         /* If mode of the inode was changed, then do a forcible ->setattr */
 168         if (mode != inode->i_mode) {
 169                 SetModeFlag(orangefs_inode);
 170                 inode->i_mode = mode;
 171                 orangefs_flush_inode(inode);
 172         }
 173
 174         return error;
 175 }