# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1627598724 -7200
# Node ID efaffd8182eeb054b64cb9f7a0e8b77c8ff5e1ec
# Parent  40729d5e6af2937595431f604721e50a56b7bbf6
Introduced locking around filesystem operations.

diff -r 40729d5e6af2 -r efaffd8182ee libfsserver/include/fsserver/ext2_file_operations.h
--- a/libfsserver/include/fsserver/ext2_file_operations.h	Fri Jul 30 00:20:35 2021 +0200
+++ b/libfsserver/include/fsserver/ext2_file_operations.h	Fri Jul 30 00:45:24 2021 +0200
@@ -21,6 +21,8 @@
 
 #pragma once
 
+#include <mutex>
+
 #include <ext2fs/ext2fs.h>
 
 #include <systypes/base.h>
@@ -33,6 +35,7 @@
 class Ext2FileOperations
 {
 protected:
+    std::mutex _lock;
     ext2_filsys _fs;
 
 public:
diff -r 40729d5e6af2 -r efaffd8182ee libfsserver/lib/files/ext2_file_operations.cc
--- a/libfsserver/lib/files/ext2_file_operations.cc	Fri Jul 30 00:20:35 2021 +0200
+++ b/libfsserver/lib/files/ext2_file_operations.cc	Fri Jul 30 00:45:24 2021 +0200
@@ -34,6 +34,8 @@
     if (!path_is_leafname(filename))
         return -L4_EINVAL;
 
+    std::lock_guard<std::mutex> guard(_lock);
+
     struct ext2_inode inode_parent;
     errcode_t retval = ext2fs_read_inode(_fs, ino_parent, &inode_parent);
 
@@ -56,6 +58,8 @@
 long Ext2FileOperations::find_file(const char *path, ext2_ino_t *ino,
                                    const char **remaining)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     *remaining = path;
     errcode_t retval = image_find_path(_fs, remaining, ino);
 
@@ -71,6 +75,8 @@
 
 void Ext2FileOperations::close_file(ext2_file_t file)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     ext2fs_file_flush(file);
     ext2fs_file_close(file);
 }
@@ -79,6 +85,8 @@
 
 long Ext2FileOperations::open_file(ext2_ino_t ino, ext2_file_t *file)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     errcode_t retval = ext2fs_file_open(_fs, ino, EXT2_FILE_WRITE, file);
 
     // NOTE: Map error conditions.
@@ -93,6 +101,8 @@
 
 offset_t Ext2FileOperations::get_size(ext2_file_t file)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     return ext2fs_file_get_size(file);
 }
 
@@ -100,6 +110,8 @@
 
 void Ext2FileOperations::set_size(ext2_file_t file, offset_t size)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     ext2fs_file_set_size(file, size);
 }
 
@@ -107,6 +119,8 @@
 
 offset_t Ext2FileOperations::read_file(ext2_file_t file, offset_t filepos, void *addr, offset_t size)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     unsigned int nread;
 
     ext2fs_file_llseek(file, filepos, SEEK_SET, NULL);
@@ -119,6 +133,8 @@
 
 void Ext2FileOperations::write_file(ext2_file_t file, offset_t filepos, const void *addr, offset_t size)
 {
+    std::lock_guard<std::mutex> guard(_lock);
+
     ext2fs_file_llseek(file, filepos, SEEK_SET, NULL);
     ext2fs_file_write(file, addr, size, NULL);
 }