-

1 files changed, 49 insertions, 6 deletions

diff --git a/pgfuse.c b/pgfuse.c
index ec267a5..8c4a6dd 100644
--- a/pgfuse.c
+++ b/pgfuse.c
@@ -30,6 +30,8 @@
 #include <fuse.h>		/* for user-land filesystem */
 #include <fuse_opt.h>		/* fuse command line parser */
 
+#include <pthread.h>		/* for mutexes */
+
 #if FUSE_VERSION < 28
 #error Currently only written for newest FUSE  APIversion (FUSE_VERSION 28)
 #endif
@@ -38,14 +40,20 @@
 #include "pgsql.h"		/* implements Postgresql accessers */
 #include "pool.h"		/* implements the connection pool */
 
-/* --- fuse callbacks --- */
+/* --- FUSE private context data --- */
+
+typedef struct PgFuseFile {
+	int id;			/* id as in the database and in the FUSE context (fh) */
+	pthread_mutex_t lock;	/* lock parallel thread operations on the same file */
+} PgFuseFile;
 
 typedef struct PgFuseData {
 	int verbose;		/* whether we should be verbose */
 	char *conninfo;		/* connection info as used in PQconnectdb */
 	char *mountpoint;	/* where we mount the virtual filesystem */
-	PGconn *conn;		/* the database handle to operate on (single-thread) */
-	PgConnPool pool;	/* the database pool to operate on (multi-thread) */
+	PGconn *conn;		/* the database handle to operate on (single-thread only) */
+	PgConnPool pool;	/* the database pool to operate on (multi-thread only) */
+	PgFuseFile files[MAX_NOF_OPEN_FILES]; /* synchronization array (multi-thread only) */
 	int read_only;		/* whether the mount point is read-only */
 	int multi_threaded;	/* whether we run multi-threaded */
 } PgFuseData;
@@ -121,11 +129,40 @@ static void *pgfuse_init( struct fuse_conn_info *conn )
 		}
 	} else {
 		int res;
+		int i;
+		pthread_mutexattr_t attr;
+
 		res = psql_pool_init( &data->pool, data->conninfo, MAX_DB_CONNECTIONS );
 		if( res < 0 ) {
 			syslog( LOG_ERR, "Allocating database connection pool failed!" );
 			exit( EXIT_FAILURE );
 		}
+
+		res = pthread_mutexattr_init( &attr );
+		if( res < 0 ) {		
+			syslog( LOG_ERR, "Error while initalizing thread attributes: %d!", res );
+			exit( EXIT_FAILURE );
+		}
+		res = pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
+		if( res < 0 ) {
+			syslog( LOG_ERR, "Error while setting thread attributes: %d!", res );
+			exit( EXIT_FAILURE );
+		}
+		
+		memset( &data->files, 0, sizeof( PgFuseFile ) * MAX_NOF_OPEN_FILES );
+		for( i = 0; i < MAX_NOF_OPEN_FILES; i++ ) {
+			res = pthread_mutex_init( &data->files[i].lock, &attr );
+			if( res < 0 ) {
+				syslog( LOG_ERR, "Error while initializing mutex: %d!", res );
+				exit( EXIT_FAILURE );
+			}
+		}
+
+		res = pthread_mutexattr_destroy( &attr );
+		if( res < 0 ) {
+			syslog( LOG_ERR, "Error while destroying thread attributes: %d!", res );
+			exit( EXIT_FAILURE );
+		}
 	}
 	
 	return data;
@@ -134,7 +171,8 @@ static void *pgfuse_init( struct fuse_conn_info *conn )
 static void pgfuse_destroy( void *userdata )
 {
 	PgFuseData *data = (PgFuseData *)userdata;
-
+	int i;
+	
 	syslog( LOG_INFO, "Unmounting file system on '%s' (%s), thread #%u",
 		data->mountpoint, data->conninfo, THREAD_ID );
 
@@ -143,6 +181,10 @@ static void pgfuse_destroy( void *userdata )
 	} else {
 		(void)psql_pool_destroy( &data->pool );
 	}
+	
+	for( i = 0; i < MAX_NOF_OPEN_FILES; i++ ) {
+		(void)pthread_mutex_destroy( &data->files[i].lock );
+	}
 }
 
 static int pgfuse_fgetattr( const char *path, struct stat *stbuf, struct fuse_file_info *fi )
@@ -422,11 +464,12 @@ static int pgfuse_open( const char *path, struct fuse_file_info *fi )
 	}
 	
 	/* currently don't allow parallel access */
-	if( meta.ref_count > 0 ) {
+/*
+  	if( meta.ref_count > 0 ) {
 		PSQL_ROLLBACK( conn ); RELEASE( conn );
 		return -ETXTBSY;
 	}
-	
+*/	
 	if( data->verbose ) {
 		syslog( LOG_DEBUG, "Id for file '%s' to open is %d, thread #%u",
 			path, id, THREAD_ID );