Merge pull request #1063 from gaul/truncate-2nd-open-fd

Flush file when opening second fd

src/cache.cpp

@@ -220,7 +220,7 @@ void StatCache::Clear()
   S3FS_MALLOCTRIM(0);
 }
 
-bool StatCache::GetStat(string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce)
+bool StatCache::GetStat(const string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce)
 {
   bool is_delete_cache = false;
   string strpath = key;

src/cache.h

@@ -65,7 +65,7 @@ class StatCache
     ~StatCache();
 
     void Clear(void);
-    bool GetStat(std::string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce);
+    bool GetStat(const std::string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce);
     // Truncate stat cache
     bool TruncateCache(void);
 
@@ -93,19 +93,19 @@ class StatCache
     }
 
     // Get stat cache
-    bool GetStat(std::string& key, struct stat* pst, headers_t* meta, bool overcheck = true, bool* pisforce = NULL) {
+    bool GetStat(const std::string& key, struct stat* pst, headers_t* meta, bool overcheck = true, bool* pisforce = NULL) {
       return GetStat(key, pst, meta, overcheck, NULL, pisforce);
     }
-    bool GetStat(std::string& key, struct stat* pst, bool overcheck = true) {
+    bool GetStat(const std::string& key, struct stat* pst, bool overcheck = true) {
       return GetStat(key, pst, NULL, overcheck, NULL, NULL);
     }
-    bool GetStat(std::string& key, headers_t* meta, bool overcheck = true) {
+    bool GetStat(const std::string& key, headers_t* meta, bool overcheck = true) {
       return GetStat(key, NULL, meta, overcheck, NULL, NULL);
     }
-    bool HasStat(std::string& key, bool overcheck = true) {
+    bool HasStat(const std::string& key, bool overcheck = true) {
       return GetStat(key, NULL, NULL, overcheck, NULL, NULL);
     }
-    bool HasStat(std::string& key, const char* etag, bool overcheck = true) {
+    bool HasStat(const std::string& key, const char* etag, bool overcheck = true) {
       return GetStat(key, NULL, NULL, overcheck, etag, NULL);
     }
 

src/s3fs.cpp

@@ -2143,7 +2143,13 @@ static int s3fs_open(const char* _path, struct fuse_file_info* fi)
   // clear stat for reading fresh stat.
   // (if object stat is changed, we refresh it. then s3fs gets always
   // stat when s3fs open the object).
-  StatCache::getStatCacheData()->DelStat(path);
+  if(StatCache::getStatCacheData()->HasStat(path)){
+    // flush any dirty data so that subsequent stat gets correct size
+    if((result = s3fs_flush(_path, fi)) != 0){
+      S3FS_PRN_ERR("could not flush(%s): result=%d", path, result);
+    }
+    StatCache::getStatCacheData()->DelStat(path);
+  }
 
   int mask = (O_RDONLY != (fi->flags & O_ACCMODE) ? W_OK : R_OK);
   if(0 != (result = check_parent_object_access(path, X_OK))){

test/integration-test-main.sh

@@ -547,6 +547,15 @@ function test_concurrency {
     rm -f `seq 100`
 }
 
+function test_open_second_fd {
+    describe "read from an open fd"
+    rm -f ${TEST_TEXT_FILE}
+    RESULT=$( (echo foo ; wc -c < ${TEST_TEXT_FILE} >&2) 2>& 1>${TEST_TEXT_FILE})
+    if [ "$RESULT" -ne 4 ]; then
+        echo "size mismatch, expected: 4, was: ${RESULT}"
+        return 1
+    fi
+}
 
 function add_all_tests {
     add_tests test_append_file 
@@ -574,6 +583,7 @@ function add_all_tests {
     add_tests test_write_after_seek_ahead
     add_tests test_overwrite_existing_file_range
     add_tests test_concurrency
+    add_tests test_open_second_fd
 }
 
 init_suite