Fix a bunch of warnings from -Wall.

Several comparisons between signed and non-signed integers. Fixed by using size_t instead of int in a number of places.
One unused variable. Removed.
No return value from gridfs_mknod(). It doesn't do anything yet, so just return 0.

Makefile

@@ -1,4 +1,4 @@
-CXXFLAGS += -g -std=c++11 -D_FILE_OFFSET_BITS=64 -I.
+CXXFLAGS += -g -std=c++11 -D_FILE_OFFSET_BITS=64 -I. -Wall
 
 MACHINE = $(shell uname -s)
 

local_gridfile.cpp

@@ -6,8 +6,8 @@ using namespace std;
 
 int LocalGridFile::write(const char *buf, size_t nbyte, off_t offset)
 {
-    int last_chunk = (offset + nbyte) / _chunkSize;
-    int written = 0;
+    size_t last_chunk = (offset + nbyte) / _chunkSize;
+    size_t written = 0;
 
     while(last_chunk > _chunks.size() - 1) {
         char *new_buf = new char[_chunkSize];
@@ -37,7 +37,7 @@ int LocalGridFile::write(const char *buf, size_t nbyte, off_t offset)
         chunk_num++;
     }
 
-    _length = max(_length, (int)offset + written);
+    _length = max(_length, offset + written);
     _dirty = true;
 
     return written;
@@ -46,7 +46,7 @@ int LocalGridFile::write(const char *buf, size_t nbyte, off_t offset)
 int LocalGridFile::read(char* buf, size_t size, off_t offset)
 {
     size_t len = 0;
-    int chunk_num = offset / _chunkSize;
+    size_t chunk_num = offset / _chunkSize;
 
     while(len < size && chunk_num < _chunks.size()) {
         const char* chunk = _chunks[chunk_num];

local_gridfile.h

@@ -15,7 +15,7 @@ const unsigned int DEFAULT_CHUNK_SIZE = 256 * 1024;
 class LocalGridFile {
  public:
   LocalGridFile(int chunkSize = DEFAULT_CHUNK_SIZE) :
-    _chunkSize(chunkSize), _length(0), _dirty(true) {
+    _length(0), _chunkSize(chunkSize), _dirty(true) {
     _chunks.push_back(new char[_chunkSize]);
   }
 
@@ -38,7 +38,7 @@ class LocalGridFile {
   typedef std::shared_ptr<LocalGridFile> ptr;
 
 private:
-  int _chunkSize, _length;
+  size_t _length, _chunkSize;
   bool _dirty;
   std::vector<char*> _chunks;
 };

operations.cpp

@@ -62,7 +62,6 @@ std::shared_ptr<ScopedDbConnection> make_ScopedDbConnection(void) {
 }
 
 int gridfs_getattr(const char *path, struct stat *stbuf) {
-  int res = 0;
   memset(stbuf, 0, sizeof(struct stat));
 
   if (strcmp(path, "/") == 0) {
@@ -251,7 +250,7 @@ int gridfs_listxattr(const char* path, char* list, size_t size) {
   if (!file.exists())
     return -ENOENT;
 
-  int len = 0;
+  size_t len = 0;
   BSONObj metadata = file.getMetadata();
   set<string> field_set;
   metadata.getFieldNames(field_set);
@@ -301,7 +300,7 @@ int gridfs_getxattr(const char* path, const char* name, char* value, size_t size
     return -ENOATTR;
 
   string field_str = field.toString();
-  int len = field_str.size() + 1;
+  size_t len = field_str.size() + 1;
   if (size == 0)
     return len;
   if (len >= size)
@@ -510,4 +509,5 @@ int gridfs_rename(const char* old_path, const char* new_path) {
 int gridfs_mknod(const char *path, mode_t mode, dev_t rdev) {
   // POSIX TODO
   fprintf(stderr, "MKNOD: %s\n", path); 
+  return 0;
 }

utils.h

@@ -31,17 +31,17 @@ inline const char* fuse_to_mongo_path(const char* path) {
 inline const bool is_leaf(const char* path) {
   int pp = -1;
   int sp = -1;
-  for(int i=0; i<strlen(path); i++) {
-    if(path[i] == '/') sp = i;
-    if(path[i] == '.') pp = i;
+  for (size_t i = 0; i < strlen(path); i++) {
+    if (path[i] == '/') sp = i;
+    if (path[i] == '.') pp = i;
   }
   return pp > sp;
 }
 
 inline const int path_depth(const char* path) {
   int sc = 0;
-  for(int i=0; i<strlen(path); i++) {
-    if(path[i] == '/') sc++;
+  for (size_t i=0; i < strlen(path); i++) {
+    if (path[i] == '/') sc++;
   }
   return sc;
 }