Merge pull request #80 from trapexit/minfreespace-xattr

add minfreespace to xattr interface

README.md

@@ -120,6 +120,7 @@ Even if xattrs are disabled the [{list,get,set}xattrs](http://linux.die.net/man/
 ##### Keys #####
 
 * user.mergerfs.srcmounts
+* user.mergerfs.minfreespace
 * user.mergerfs.category.action
 * user.mergerfs.category.create
 * user.mergerfs.category.search
@@ -149,6 +150,7 @@ Even if xattrs are disabled the [{list,get,set}xattrs](http://linux.die.net/man/
 ```
 [trapexit:/tmp/mount] $ xattr -l .mergerfs
 user.mergerfs.srcmounts: /tmp/a:/tmp/b
+user.mergerfs.minfreespace: 4294967295
 user.mergerfs.category.action: all
 user.mergerfs.category.create: epmfs
 user.mergerfs.category.search: ff

src/getxattr.cpp

@@ -29,6 +29,7 @@
 #include <set>
 #include <algorithm>
 
+#include <stdio.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <string.h>
@@ -92,6 +93,18 @@ _getxattr_controlfile_srcmounts(const Config &config,
   attrvalue = str::join(config.srcmounts,':');
 }
 
+static
+void
+_getxattr_controlfile_minfreespace(const Config &config,
+                                   string       &attrvalue)
+{
+  char buf[64];
+
+  snprintf(buf,sizeof(buf),"%li",config.minfreespace);
+
+  attrvalue = buf;
+}
+
 static
 int
 _getxattr_controlfile(const Config &config,
@@ -108,6 +121,8 @@ _getxattr_controlfile(const Config &config,
 
   if(!strcmp("srcmounts",attrbasename))
     _getxattr_controlfile_srcmounts(config,attrvalue);
+  else if(!strcmp("minfreespace",attrbasename))
+    _getxattr_controlfile_minfreespace(config,attrvalue);
   else if(!strncmp("category.",attrbasename,sizeof("category.")-1))
     _getxattr_controlfile_category_policy(config,&attrbasename[sizeof("category.")-1],attrvalue);
   else if(!strncmp("func.",attrbasename,sizeof("func.")-1))

src/listxattr.cpp

@@ -37,6 +37,7 @@
 #include "ugid.hpp"
 #include "rwlock.hpp"
 #include "xattr.hpp"
+#include "buildvector.hpp"
 
 using std::string;
 using std::vector;
@@ -48,12 +49,17 @@ _listxattr_controlfile(char         *list,
                        const size_t  size)
 {
   string xattrs;
+  const vector<string> strs =
+    buildvector<string>
+    ("user.mergerfs.srcmounts")
+    ("user.mergerfs.minfreespace");
 
   xattrs.reserve(512);
-  xattrs.append("user.mergerfs.srcmounts",sizeof("user.mergerfs.srcmounts"));
-  for(int i = Category::Enum::BEGIN; i < Category::Enum::END; i++)
+  for(size_t i = 0; i < strs.size(); i++)
+    xattrs += (strs[i] + '\0');
+  for(size_t i = Category::Enum::BEGIN; i < Category::Enum::END; i++)
     xattrs += ("user.mergerfs.category." + (std::string)*Category::categories[i] + '\0');
-  for(int i = FuseFunc::Enum::BEGIN; i < FuseFunc::Enum::END; i++)
+  for(size_t i = FuseFunc::Enum::BEGIN; i < FuseFunc::Enum::END; i++)
     xattrs += ("user.mergerfs.func." + (std::string)*FuseFunc::fusefuncs[i] + '\0');
 
   if(size == 0)

src/option_parser.cpp

@@ -35,6 +35,7 @@
 #include <iostream>
 
 #include "str.hpp"
+#include "num.hpp"
 #include "config.hpp"
 #include "policy.hpp"
 
@@ -106,29 +107,11 @@ int
 parse_and_process_minfreespace(const std::string &value,
                                size_t            &minfreespace)
 {
-  char *endptr;
-
-  minfreespace = strtoll(value.c_str(),&endptr,10);
-  switch(*endptr)
-    {
-    case 'k':
-    case 'K':
-      minfreespace *= 1024;
-      break;
-
-    case 'm':
-    case 'M':
-      minfreespace *= (1024 * 1024);
-      break;
-
-    case 'g':
-    case 'G':
-      minfreespace *= (1024 * 1024 * 1024);
-      break;
+  int rv;
 
-    default:
+  rv = num::to_size_t(value,minfreespace);
+  if(rv == -1)
     return 1;
-    }
 
   return 0;
 }

src/setxattr.cpp

@@ -38,6 +38,7 @@
 #include "rwlock.hpp"
 #include "xattr.hpp"
 #include "str.hpp"
+#include "num.hpp"
 
 using std::string;
 using std::vector;
@@ -165,6 +166,24 @@ _setxattr_srcmounts(vector<string>   &srcmounts,
   return -EINVAL;
 }
 
+static
+int
+_setxattr_minfreespace(config::Config &config,
+                       const string   &attrval,
+                       const int       flags)
+{
+  int rv;
+
+  if((flags & XATTR_CREATE) == XATTR_CREATE)
+    return -EEXIST;
+
+  rv = num::to_size_t(attrval,config.minfreespace);
+  if(rv == -1)
+    return -EINVAL;
+
+  return 0;
+}
+
 static
 int
 _setxattr_controlfile_func_policy(config::Config &config,
@@ -224,6 +243,10 @@ _setxattr_controlfile(config::Config &config,
                                config.destmount,
                                attrval,
                                flags);
+  else if(!strcmp("minfreespace",attrbasename))
+    return _setxattr_minfreespace(config,
+                                  attrval,
+                                  flags);
   else if(!strncmp("category.",attrbasename,sizeof("category.")-1))
     return _setxattr_controlfile_category_policy(config,
                                                  &attrbasename[sizeof("category.")-1],