New flag bit7 with iso_local_set_attrs() to avoid unnecessary write attempts. New return value 2 of IsoFileSource.get_aa_string() and iso_local_get_attrs(). New API calls iso_image_was_blind_attrs(), iso_local_set_attrs_errno().

libisofs/aaip-os-dummy.c

@@ -99,10 +99,14 @@ int aaip_set_acl_text(char *path, char *text, int flag)
                        -7 support of ACL not enabled at compile time
 */
 int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
-                       size_t *value_lengths, char **values, int flag)
+                       size_t *value_lengths, char **values, int *errnos,
+                       int flag)
 {
  size_t i;
 
+ for(i= 0; i < num_attrs; i++)
+   errnos[i]= 0;
+
  for(i= 0; i < num_attrs; i++) {
    if(names[i] == NULL || values[i] == NULL)
  continue;

libisofs/aaip-os-freebsd.c

@@ -228,6 +228,10 @@ static int aaip_extattr_make_list(char *path, int attrnamespace,
      *list_size = 0;
      return(2);
    }
+   if(errno == EPERM && attrnamespace == EXTATTR_NAMESPACE_SYSTEM) {
+     *list_size = 0;
+     return(3);
+   }
    return(0);
  }
  if(*list_size == 0)
@@ -312,6 +316,54 @@ static int aaip_extattr_make_namelist(char *path, char *attrnamespace,
  return(1);
 }
 
+
+static int get_single_attr(char *path, char *name, size_t *value_length,
+                           char **value_bytes, int flag)
+{
+ char *namept;
+ int attrnamespace;
+ ssize_t value_ret;
+ 
+ *value_bytes= NULL;
+ *value_length= 0;
+ if(strncmp(name, "user.", 5) == 0) {
+   attrnamespace= EXTATTR_NAMESPACE_USER;
+   namept= name + 5;
+ } else {
+   if(!(flag & 8))
+     return(0);
+   attrnamespace= EXTATTR_NAMESPACE_SYSTEM;
+   namept= name + 7;
+ }
+ /* Predict length of value */
+ if(flag & 32) /* follow link */
+   value_ret= extattr_get_file(path, attrnamespace, namept, NULL, (size_t) 0);
+ else
+   value_ret= extattr_get_link(path, attrnamespace, namept, NULL, (size_t) 0);
+ if(value_ret == -1)
+   return(0);
+
+ *value_bytes= calloc(value_ret + 1, 1);
+ if(*value_bytes == NULL)
+   return(-1);
+
+ /* Obtain value */
+ if(flag & 32) /* follow link */
+   value_ret= extattr_get_file(path, attrnamespace, namept,
+                               *value_bytes, (size_t) value_ret);
+ else
+   value_ret= extattr_get_link(path, attrnamespace, namept,
+                               *value_bytes, (size_t) value_ret);
+ if(value_ret == -1) {
+   free(*value_bytes);
+   *value_bytes= NULL;
+   *value_length= 0;
+   return(0);
+ }
+ *value_length= value_ret;
+ return(1);
+}
+
 #endif /* Libisofs_with_freebsd_extattR */
 
 
@@ -332,7 +384,8 @@ static int aaip_extattr_make_namelist(char *path, char *attrnamespace,
                         bit4=  do not return trivial ACL that matches st_mode
                         bit5=  in case of symbolic link: inquire link target
                         bit15= free memory of names, value_lengths, values
-   @return              >0  ok
+   @return              1   ok
+                        2   ok, no permission to inspect non-user namespaces
                         <=0 error
                         -1= out of memory
                         -2= program error with prediction of result size
@@ -350,11 +403,10 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
  size_t a_acl_len= 0;
 #endif
 #ifdef Libisofs_with_freebsd_extattR
- char *list= NULL, *user_list= NULL, *sys_list= NULL, *namept;
- ssize_t value_ret, retry= 0, list_size= 0, user_list_size= 0;
+ char *list= NULL, *user_list= NULL, *sys_list= NULL;
+ ssize_t value_ret, list_size= 0, user_list_size= 0;
  ssize_t sys_list_size= 0;
- int attrnamespace;
- int acl_names= 0;
+ int acl_names= 0, no_perm_for_system= 0;
 #endif
 
  if(flag & (1 << 15)) { /* Free memory */
@@ -391,6 +443,8 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
                                  &sys_list, &sys_list_size, flag & 32);
      if(ret <= 0)
        {ret= -1; goto ex;}
+     if(ret == 3)
+       no_perm_for_system= 1;
    }
 
    /* Check for NUL in names, convert into a linuxish list of namespace.name */
@@ -445,45 +499,10 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
    }
  
    for(i= 0; (size_t) i < *num_attrs; i++) {
-     if(strncmp((*names)[i], "user.", 5) == 0) {
-       attrnamespace= EXTATTR_NAMESPACE_USER;
-       namept= (*names)[i] + 5;
-     } else {
-       if(!(flag & 8))
-   continue;
-       attrnamespace= EXTATTR_NAMESPACE_SYSTEM;
-       namept= (*names)[i] + 7;
-     }
-     /* Predict length of value */
-     if(flag & 32) /* follow link */
-       value_ret= extattr_get_file(path, attrnamespace, namept,
-                                   NULL, (size_t) 0);
-     else
-       value_ret= extattr_get_link(path, attrnamespace, namept,
-                                   NULL, (size_t) 0);
-     if(value_ret == -1)
- continue;
-
-     (*values)[i]= calloc(value_ret + 1, 1);
-     if((*values)[i] == NULL)
+     value_ret= get_single_attr(path, (*names)[i], *value_lengths + i,
+                                *values + i, flag & (8 | 32));
+     if(value_ret <= 0)
        {ret= -1; goto ex;}
-
-     /* Obtain value */
-     if(flag & 32) /* follow link */
-       value_ret= extattr_get_file(path, attrnamespace, namept,
-                                   (*values)[i], (size_t) value_ret);
-     else
-       value_ret= extattr_get_link(path, attrnamespace, namept,
-                                   (*values)[i], (size_t) value_ret);
-     if(value_ret == -1) { /* there could be a race condition */
-
-       if(retry++ > 5)
-         {ret= -1; goto ex;}
-       i--;
- continue;
-     }
-     (*value_lengths)[i]= value_ret;
-     retry= 0;
    }
  }
 
@@ -494,8 +513,11 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
  if(flag & 1) { /* Obtain ACL */
   /* access-ACL */
    aaip_get_acl_text(path, &a_acl_text, flag & (16 | 32));
-   if(a_acl_text == NULL)
-     {ret= 1; goto ex;} /* empty ACL / only st_mode info was found in ACL */
+   if(a_acl_text == NULL) {
+     /* empty ACL / only st_mode info was found in ACL */
+     ret= 1 + no_perm_for_system;
+     goto ex;
+   }
    ret= aaip_encode_acl(a_acl_text, (mode_t) 0, &a_acl_len, &a_acl, flag & 2);
    if(ret <= 0)
      goto ex;
@@ -514,7 +536,7 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
 
 #endif /* Libisofs_with_aaip_acL */
 
- ret= 1;
+ ret= 1 + no_perm_for_system;
 ex:;
 #ifdef Libisofs_with_aaip_acL
  if(a_acl != NULL)
@@ -773,6 +795,15 @@ static int aaip_extattr_delete_names(char *path, int attrnamespace,
 #endif /* Libisofs_with_freebsd_extattR */
 
 
+static void register_errno(int *errnos, int i, int in_errno)
+{
+ if(in_errno > 0)
+   errnos[i]= in_errno;
+ else
+   errnos[i]= -1;
+}
+
+
 /* Bring the given attributes and/or ACLs into effect with the given file.
    @param flag          Bitfield for control purposes
                         bit0= decode and set ACLs
@@ -784,6 +815,8 @@ static int aaip_extattr_delete_names(char *path, int attrnamespace,
                         bit5= in case of symbolic link: manipulate link target
                         bit6= tolerate inappropriate presence or absence of
                               directory default ACL
+                        bit7= void setting a name value pair if it already
+                              exists and has the desired value.
    @return              1 success
                        -1 error memory allocation
                        -2 error with decoding of ACL
@@ -796,17 +829,23 @@ static int aaip_extattr_delete_names(char *path, int attrnamespace,
     ISO_AAIP_ACL_MULT_OBJ multiple entries of user::, group::, other::
 */
 int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
-                       size_t *value_lengths, char **values, int flag)
+                       size_t *value_lengths, char **values,
+                       int *errnos,  int flag)
 {
- int ret, has_default_acl= 0;
+ int ret, has_default_acl= 0, end_ret= 1;
  size_t i, consumed, acl_text_fill, acl_idx= 0;
  char *acl_text= NULL;
 #ifdef Libisofs_with_freebsd_extattR
- char *user_list= NULL, *sys_list= NULL, *namept;
- ssize_t user_list_size= 0, sys_list_size= 0;
+ char *user_list= NULL, *sys_list= NULL, *namept, *old_value;
+ ssize_t user_list_size= 0, sys_list_size= 0, value_ret;
  int attrnamespace;
+ size_t old_value_l;
+ int skip;
 #endif
 
+ for(i= 0; i < num_attrs; i++)
+   errnos[i]= 0;
+
 #ifdef Libisofs_with_freebsd_extattR
 
  if(flag & 2) { /* Delete all file attributes */
@@ -855,16 +894,35 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
      attrnamespace= EXTATTR_NAMESPACE_SYSTEM;
      namept= names[i] + 7;
    } else {
-     {ret= -8; goto ex;}
+     register_errno(errnos, i, (int) EFAULT);
+     end_ret= -8;
+ continue;
+   }
+   skip= 0;
+   if(flag & 128) {
+     value_ret= get_single_attr(path, names[i], &old_value_l,
+                                &old_value, flag & (8 | 32));
+     if(value_ret > 0 && old_value_l == value_lengths[i]) {
+       if(memcmp(old_value, values[i], value_lengths[i]) == 0)
+         skip= 1;
+     }
+     if(old_value != NULL)
+       free(old_value);
+   }
+   if(!skip) {
+     if(flag & 32)
+       ret= extattr_set_file(path, attrnamespace, namept,
+                             values[i], value_lengths[i]);
+     else
+       ret= extattr_set_link(path, attrnamespace, namept,
+                             values[i], value_lengths[i]);
+     if(ret == -1) {
+       register_errno(errnos, i, errno);
+       if(end_ret != 1)
+         end_ret= -4;
+ continue;
+     }
    }
-   if(flag & 32)
-     ret= extattr_set_file(path, attrnamespace, namept,
-                           values[i], value_lengths[i]);
-   else
-     ret= extattr_set_link(path, attrnamespace, namept,
-                           values[i], value_lengths[i]);
-   if(ret == -1)
-     {ret= -4; goto ex;}
 
 #else
 
@@ -879,8 +937,12 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
  }
 
  /* Decode ACLs */
+ /* It is important that this happens after restoring xattr which might be
+    representations of ACL, too. If isofs ACL are enabled, then they shall
+    override the xattr ones.
+ */
  if(acl_idx == 0)
-   {ret= 1; goto ex;}
+   {ret= end_ret; goto ex;}
  i= acl_idx - 1; 
 
  ret= aaip_decode_acl((unsigned char *) values[i], value_lengths[i],
@@ -902,6 +964,8 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
 
 #ifdef Libisofs_with_aaip_acL
  ret= aaip_set_acl_text(path, acl_text, flag & (32 | 64));
+ if(ret == -1)
+    register_errno(errnos, i, errno);
  if(ret <= 0)
    {ret= -3; goto ex;}
 #else
@@ -911,7 +975,7 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
  if(has_default_acl && !(flag & 64))
    {ret= -3; goto ex;}
 
- ret= 1;
+ ret= end_ret;
 ex:;
  if(acl_text != NULL)
    free(acl_text);

libisofs/aaip-os-linux.c

@@ -159,6 +159,41 @@ int aaip_get_acl_text(char *path, char **text, int flag)
 }
 
 
+#ifdef Libisofs_with_aaip_xattR
+
+static int get_single_attr(char *path, char *name, size_t *value_length,
+                           char **value_bytes, int flag)
+{
+ ssize_t value_ret;
+
+ *value_bytes= NULL;
+ *value_length= 0;
+ if(flag & 32)
+   value_ret= getxattr(path, name, NULL, 0);
+ else
+   value_ret= lgetxattr(path, name, NULL, 0);
+ if(value_ret == -1)
+   return(0);
+ *value_bytes= calloc(value_ret + 1, 1);
+ if(*value_bytes == NULL)
+   return(-1);
+ if(flag & 32)
+   value_ret= getxattr(path, name, *value_bytes, value_ret);
+ else
+   value_ret= lgetxattr(path, name, *value_bytes, value_ret);
+ if(value_ret == -1) {
+   free(*value_bytes);
+   *value_bytes= NULL;
+   *value_length= 0;
+   return(0);
+ }
+ *value_length= value_ret;
+ return(1);
+}
+
+#endif /* Libisofs_with_aaip_xattR */
+
+
 /* Obtain the Extended Attributes and/or the ACLs of the given file in a form
    that is ready for aaip_encode().
    @param path          Path to the file
@@ -176,7 +211,9 @@ int aaip_get_acl_text(char *path, char **text, int flag)
                         bit4=  do not return trivial ACL that matches st_mode
                         bit5=  in case of symbolic link: inquire link target
                         bit15= free memory of names, value_lengths, values
-   @return              >0  ok
+   @return              1  ok
+                        (reserved for FreeBSD: 2 ok, no permission to inspect
+                                                 non-user namespaces.)
                         <=0 error
                         -1= out of memory
                         -2= program error with prediction of result size
@@ -195,7 +232,7 @@ int aaip_get_attr_list(char *path, size_t *num_attrs, char ***names,
 #endif
 #ifdef Libisofs_with_aaip_xattR
  char *list= NULL;
- ssize_t value_ret, retry= 0, list_size= 0;
+ ssize_t value_ret, list_size= 0;
 #define Libisofs_aaip_get_attr_activE yes
 #endif
 #ifdef Libisofs_aaip_get_attr_activE
@@ -288,27 +325,10 @@ ex:;
      if(!(flag & 8))
        if(strncmp((*names)[i], "user.", 5))
    continue;
-     if(flag & 32)
-       value_ret= getxattr(path, (*names)[i], NULL, 0);
-     else
-       value_ret= lgetxattr(path, (*names)[i], NULL, 0);
-     if(value_ret == -1)
- continue;
-     (*values)[i]= calloc(value_ret + 1, 1);
-     if((*values)[i] == NULL)
+     value_ret= get_single_attr(path, (*names)[i], *value_lengths + i,
+                                *values + i, flag & 32);
+     if(value_ret <= 0)
        {ret= -1; goto ex;}
-     if(flag & 32)
-       value_ret= getxattr(path, (*names)[i], (*values)[i], value_ret);
-     else
-       value_ret= lgetxattr(path, (*names)[i], (*values)[i], value_ret);
-     if(value_ret == -1) { /* there could be a race condition */
-       if(retry++ > 5)
-         {ret= -1; goto ex;}
-       i--;
- continue;
-     }
-     (*value_lengths)[i]= value_ret;
-     retry= 0;
    }
  }
 
@@ -434,6 +454,15 @@ ex:
 }
 
 
+static void register_errno(int *errnos, int i)
+{
+ if(errno > 0)
+   errnos[i]= errno;
+ else
+   errnos[i]= -1;
+}
+
+
 /* Bring the given attributes and/or ACLs into effect with the given file.
    @param flag          Bitfield for control purposes
                         bit0= decode and set ACLs
@@ -445,6 +474,9 @@ ex:
                         bit5= in case of symbolic link: manipulate link target
                         bit6= tolerate inappropriate presence or absence of
                               directory default ACL
+                        bit7= @since 1.5.0
+                              avoid setting a name value pair if it already
+                              exists and has the desired value.
    @return              1 success
                        -1 error memory allocation
                        -2 error with decoding of ACL
@@ -457,20 +489,25 @@ ex:
     ISO_AAIP_ACL_MULT_OBJ multiple entries of user::, group::, other::
 */
 int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
-                       size_t *value_lengths, char **values, int flag)
+                       size_t *value_lengths, char **values,
+                       int *errnos, int flag)
 {
- int ret;
+ int ret, end_ret= 1;
  size_t i, consumed, acl_text_fill, acl_idx= 0;
  char *acl_text= NULL;
 #ifdef Libisofs_with_aaip_xattR
- char *list= NULL;
- ssize_t list_size= 0;
+ char *list= NULL, *old_value;
+ ssize_t list_size= 0, value_ret;
+ size_t old_value_l;
+ int skip;
 #endif
 #ifdef Libisofs_with_aaip_acL
  size_t h_consumed;
  int has_default_acl= 0;
 #endif
 
+ for(i= 0; i < num_attrs; i++)
+   errnos[i]= 0;
 
 #ifdef Libisofs_with_aaip_xattR
 
@@ -525,12 +562,28 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
 
 #ifdef Libisofs_with_aaip_xattR
 
-   if(flag & 32)
-     ret= setxattr(path, names[i], values[i], value_lengths[i], 0);
-   else
-     ret= lsetxattr(path, names[i], values[i], value_lengths[i], 0);
-   if(ret == -1)
-     {ret= -4; goto ex;}
+   skip= 0;
+   if(flag & 128) {
+     value_ret= get_single_attr(path, names[i], &old_value_l,
+                                &old_value, flag & 32);
+     if(value_ret > 0 && old_value_l == value_lengths[i]) {
+       if(memcmp(old_value, values[i], value_lengths[i]) == 0)
+         skip= 1;
+     }
+     if(old_value != NULL)
+       free(old_value);
+   }
+   if(!skip) {
+     if(flag & 32)
+       ret= setxattr(path, names[i], values[i], value_lengths[i], 0);
+     else
+       ret= lsetxattr(path, names[i], values[i], value_lengths[i], 0);
+     if(ret == -1) {
+       register_errno(errnos, i);
+       end_ret= -4;
+ continue;
+     }
+   }
 
 #else
 
@@ -540,9 +593,13 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
 
  }
 
-/* Decode ACLs */
+ /* Decode ACLs */
+ /* It is important that this happens after restoring xattr which might be
+    representations of ACL, too. If isofs ACL are enabled, then they shall
+    override the xattr ones.
+ */
  if(acl_idx == 0)
-   {ret= 1; goto ex;}
+   {ret= end_ret; goto ex;}
  i= acl_idx - 1;
                                                              /* "access" ACL */
  ret= aaip_decode_acl((unsigned char *) values[i], value_lengths[i],
@@ -566,6 +623,8 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
  has_default_acl= (ret == 2);
 
  ret= aaip_set_acl_text(path, acl_text, flag & 32);
+ if(ret == -1)
+   register_errno(errnos, i);
  if(ret <= 0)
    {ret= -3; goto ex;}
                                                             /* "default" ACL */
@@ -590,6 +649,8 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
    if(ret <= 0)
      {ret= -2; goto ex;}
    ret= aaip_set_acl_text(path, acl_text, 1 | (flag & 32));
+   if(ret == -1)
+     register_errno(errnos, i);
    if(ret <= 0)
      {ret= -3; goto ex;}
  } else {
@@ -601,7 +662,7 @@ int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
 
    }
  }
- ret= 1;
+ ret= end_ret;
 
 #else
 

libisofs/aaip_0_2.c

@@ -2188,6 +2188,11 @@ ex:;
 /* ----------------------- Adapter for operating systems ----------------- */
 
 
+#ifdef Libisofs_use_os_dummY
+
+#include "aaip-os-dummy.c"
+
+#else
 #ifdef __FreeBSD__
 
 #include "aaip-os-freebsd.c"
@@ -2239,4 +2244,5 @@ ex:;
 #endif /* ! __NetBSD__ */
 #endif /* ! __FreeBSD_kernel__ */
 #endif /* ! __FreeBSD__ */
+#endif /* ! Libisofs_use_os_dummY */
 

libisofs/aaip_0_2.h

@@ -507,7 +507,8 @@ int aaip_set_acl_text(char *path, char *text, int flag);
     ISO_AAIP_ACL_MULT_OBJ multiple entries of user::, group::, other::
 */
 int aaip_set_attr_list(char *path, size_t num_attrs, char **names,
-                       size_t *value_lengths, char **values, int flag);
+                       size_t *value_lengths, char **values,
+                       int *errnos, int flag);
 
 #endif /* ! Aaip_h_is_includeD */
 

libisofs/builder.c

@@ -254,7 +254,9 @@ int default_create_node(IsoNodeBuilder *builder, IsoImage *image,
             1 | (image->builder_ignore_acl << 1) |
                 (image->builder_ignore_ea << 2) |
                 (image->builder_take_all_ea << 3));
-    if (ret == 1 && aa_string != NULL) {
+    if(ret == 2)
+      image->blind_on_local_get_attrs = 1;
+    if (ret > 0 && aa_string != NULL) {
         ret = iso_node_add_xinfo(new, aaip_xinfo_func, aa_string);
         if (ret < 0)
             goto ex;

libisofs/fs_local.c

@@ -499,7 +499,7 @@ void lfs_free(IsoFileSource *src)
 static 
 int lfs_get_aa_string(IsoFileSource *src, unsigned char **aa_string, int flag)
 {
-    int ret;
+    int ret, no_non_user_perm= 0;
     size_t num_attrs = 0, *value_lengths = NULL, result_len;
     ssize_t sret;
     char *path = NULL, **names = NULL, **values = NULL;
@@ -529,6 +529,9 @@ int lfs_get_aa_string(IsoFileSource *src, unsigned char **aa_string, int flag)
             ret = ISO_FILE_ERROR;
         goto ex;
     }
+    if(ret == 2)
+        no_non_user_perm= 1;
+      
     if (num_attrs == 0)
         result = NULL;
     else {
@@ -540,7 +543,7 @@ int lfs_get_aa_string(IsoFileSource *src, unsigned char **aa_string, int flag)
         }
     }
     *aa_string = result;
-    ret = 1;
+    ret = 1 + no_non_user_perm;
 ex:;
     if (path != NULL)
         free(path);
@@ -867,17 +870,19 @@ int iso_local_get_attrs(char *disk_path, size_t *num_attrs, char ***names,
                              (flag & (1 | 4 | 8 | 32 | (1 << 15))) | 2 | 16);
     if (ret <= 0)
         return ISO_AAIP_NO_GET_LOCAL;
-    return 1;
+    return 1 + (ret == 2);
 }
 
 
-int iso_local_set_attrs(char *disk_path, size_t num_attrs, char **names,
-                        size_t *value_lengths, char **values, int flag)
+int iso_local_set_attrs_errno(char *disk_path, size_t num_attrs, char **names,
+                              size_t *value_lengths, char **values,
+                              int *errnos, int flag)
 {
     int ret;
 
     ret = aaip_set_attr_list(disk_path, num_attrs, names, value_lengths,
-                             values, (flag & (8 | 32 | 64)) | !(flag & 1));
+                             values, errnos,
+                             (flag & (8 | 32 | 64 | 128)) | !(flag & 1));
     if (ret <= 0) {
         if (ret == -1)
             return ISO_OUT_OF_MEM;
@@ -895,6 +900,25 @@ int iso_local_set_attrs(char *disk_path, size_t num_attrs, char **names,
 }
 
 
+int iso_local_set_attrs(char *disk_path, size_t num_attrs, char **names,
+                        size_t *value_lengths, char **values, int flag)
+{
+    int ret;
+    int *errnos = NULL;
+
+    if(num_attrs > 0) {
+      errnos= calloc(num_attrs, sizeof(int));
+      if(errnos == NULL)
+        return ISO_OUT_OF_MEM;
+    }
+    ret= iso_local_set_attrs_errno(disk_path, num_attrs, names, value_lengths,
+                                   values, errnos, flag);
+    if(errnos != NULL)
+      free(errnos);
+    return ret;
+}
+
+
 int iso_local_get_perms_wo_acl(char *disk_path, mode_t *st_mode, int flag)
 {
     struct stat stbuf;

libisofs/image.c

@@ -203,6 +203,7 @@ int iso_image_new(const char *name, IsoImage **image)
         img->hfsplus_blessed[i] = NULL;
     img->collision_warnings = 0;
     img->imported_sa_info = NULL;
+    img->blind_on_local_get_attrs = 0;
 
     *image = img;
     return ISO_SUCCESS;
@@ -1137,3 +1138,15 @@ int iso_image_truncate_name(IsoImage *image, const char *name, char **namept,
     return ret;
 }
 
+
+/* API */
+int iso_image_was_blind_attrs(IsoImage *image, int flag)
+{
+    int ret;
+
+    ret = image->blind_on_local_get_attrs;
+    if (flag & 1)
+        image->blind_on_local_get_attrs = 0;
+    return ret;
+}
+

libisofs/image.h

@@ -247,6 +247,11 @@ struct Iso_Image
     /* Contains the assessment of boot aspects of the loaded image */
     struct iso_imported_sys_area *imported_sa_info;
 
+    /* Whether some local filesystem xattr namespace could not be explored
+     * during node building.
+     */
+    int blind_on_local_get_attrs;
+
 };
 
 

libisofs/libisofs.h

@@ -867,6 +867,10 @@ struct IsoFileSource_Iface
      *                   The caller is responsible for finally calling free()
      *                   on non-NULL results.
      * @return           1 means success (*aa_string == NULL is possible)
+     *                   2 means success, but it is possible that attributes
+     *                     exist in non-user namespaces which could not be
+     *                     explored due to lack of permission.
+     *                     @since 1.5.0
      *                  <0 means failure and must b a valid libisofs error code
      *                     (e.g. ISO_FILE_ERROR if no better one can be found).
      * @since 0.6.14
@@ -6357,6 +6361,28 @@ int iso_tree_clone(IsoNode *node,
  */
 int iso_tree_add_dir_rec(IsoImage *image, IsoDir *parent, const char *dir);
 
+/**
+ * Inquire whether some local filesystem xattr namespace could not be explored
+ * during node building. This may happen due to lack of adminstrator privileges
+ * e.g. on FreeBSD namespace "system".
+ * It may well be that the processed local files have no attributes which
+ * would require special privileges. But already their existence was neither
+ * denied nor confirmed.
+ *
+ * @param image
+ *      The image to inquire.
+ * @param flag
+ *      Bitfield for control purposes:
+ *      bit0 = reset internal value to 0
+ * @return
+ *      1 = Exploration was prevented
+ *      0 = No such prevention occured
+ *
+ * @since 1.5.0
+ */
+int iso_image_was_blind_attrs(IsoImage *image, int flag);
+
+
 /**
  * Locate a node by its absolute path in the image.
  * The IsoImage context defines a maximum permissible name length and a mode
@@ -7585,6 +7611,9 @@ int iso_local_get_perms_wo_acl(char *disk_path, mode_t *st_mode, int flag);
  *      bit15= free memory
  * @return
  *        1 ok
+ *        2 ok, but it is possible that attributes exist in non-user namespaces
+ *              which could not be explored due to lack of permission.
+ *              @since 1.5.0
  *      < 0 failure
  *
  * @since 0.6.14
@@ -7608,6 +7637,11 @@ int iso_local_get_attrs(char *disk_path, size_t *num_attrs, char ***names,
  *      Array of byte lengths for each attribute payload
  * @param values
  *      Array of pointers to the attribute payload bytes
+ * @param errnos
+ *      Array of integers to return error numbers if encountered at the attempt
+ *      to process the name-value pair at the given array index number:
+ *      0 = no error , -1 = unknown error
+ *      >0 = errno as of local system calls to set xattr and ACLs
  * @param flag
  *      Bitfield for control purposes
  *      bit0=  do not attach ACLs from an eventual attribute with empty name
@@ -7615,12 +7649,24 @@ int iso_local_get_attrs(char *disk_path, size_t *num_attrs, char ***names,
  *             I.e. those with a name which does not begin by "user."
  *      bit5=  in case of symbolic link: manipulate link target
  *      bit6=  @since 1.1.6
-               tolerate inappropriate presence or absence of
+ *             tolerate inappropriate presence or absence of
  *             directory "default" ACL
+ *      bit7=  @since 1.5.0
+ *             avoid setting a name value pair if it already exists and
+ *             has the desired value.
  * @return
  *      1 = ok 
  *    < 0 = error
  *
+ * @since 1.5.0
+ */
+int iso_local_set_attrs_errno(char *disk_path, size_t num_attrs, char **names,
+                              size_t *value_lengths, char **values,
+                              int *errnos, int flag);
+/**
+ * Older version of iso_local_set_attrs_errno() without the errnos array.
+ * All other parameters and the return value have the same meaning.
+ *
  * @since 0.6.14
  */
 int iso_local_set_attrs(char *disk_path, size_t num_attrs, char **names,

libisofs/libisofs.ver

@@ -153,6 +153,7 @@ iso_image_set_volume_id;
 iso_image_tree_clone;
 iso_image_unref;
 iso_image_update_sizes;
+iso_image_was_blind_attrs;
 iso_init;
 iso_init_with_flag;
 iso_interval_reader_destroy;
@@ -166,6 +167,7 @@ iso_local_get_attrs;
 iso_local_get_perms_wo_acl;
 iso_local_set_acl_text;
 iso_local_set_attrs;
+iso_local_set_attrs_errno;
 iso_md5_clone;
 iso_md5_compute;
 iso_md5_end;