Merge branch 'improve-mount-reference-count' into 'develop-BA-FS26'

Increase reference count of source_mount when one of its files is mounted somewhere

See merge request teachos/kernel!42

1 files changed, 40 insertions, 14 deletions

diff --git a/kernel/src/main.cpp b/kernel/src/main.cpp
index 22d2b1e..6985e94 100644
--- a/kernel/src/main.cpp
+++ b/kernel/src/main.cpp
@@ -13,7 +13,6 @@
 #include <kapi/system.hpp>
 
 #include <kstd/format>
-#include <kstd/os/error.hpp>
 #include <kstd/print>
 #include <kstd/units>
 #include <kstd/vector>
@@ -26,57 +25,84 @@ using namespace kstd::units_literals;
 auto run_demo() -> void
 {
   // 1) open a file
+  kstd::println("attempting to open /entrance/tickets.txt");
   auto fd_1 = kapi::filesystem::open("/entrance/tickets.txt");
   if (fd_1 == -1)
   {
-    kstd::os::panic("demo failed");
+    kapi::system::panic("demo failed");
+  }
+  else
+  {
+    kstd::println("--> successfully opened /entrance/tickets.txt with file descriptor {}", fd_1);
   }
 
   // 2) read from the file
   kstd::vector<std::byte> buffer_1{10};
   auto bytes_read = kapi::filesystem::read(fd_1, buffer_1.data(), buffer_1.size());
   auto buffer_as_str = std::string_view{reinterpret_cast<char *>(buffer_1.data()), static_cast<size_t>(bytes_read)};
-  kstd::println("Read {} bytes from /entrance/tickets.txt: {}", bytes_read, buffer_as_str);
+  kstd::println("--> read {} bytes from /entrance/tickets.txt: {}", bytes_read, buffer_as_str);
+  kstd::println("");
 
   // 3) show that /entrance/information/info_1.txt is not accessible before mounting
+  kstd::println("attempting to open /entrance/information/info_1.txt before mounting");
   auto fd_before_mount = kapi::filesystem::open("/entrance/information/info_1.txt");
   if (fd_before_mount == -1)
   {
-    kstd::println("/entrance/information/info_1.txt is not accessible before mounting, as expected.");
+    kstd::println("--> as expected the file could not be opened before mounting");
   }
 
   // 4) mount a new filesystem on top of /entrance
-  kapi::filesystem::mount("/dev/ram16", "/entrance");
+  kstd::println("mount /dev/ram16 to /entrance");
+  if (kapi::filesystem::mount("/dev/ram16", "/entrance") == 0)
+  {
+    kstd::println("--> successfully mounted /dev/ram16 to /entrance");
+  }
+  else
+  {
+    kapi::system::panic("demo failed");
+  }
+  kstd::println("");
 
   // 5) open a file from the new filesystem
+  kstd::println("attempting to open /entrance/information/info_1.txt");
   auto fd_2 = kapi::filesystem::open("/entrance/information/info_1.txt");
-  if (fd_2 == -1)
+  if (fd_2 != -1)
+  {
+    kstd::println("--> successfully opened /entrance/information/info_1.txt with file descriptor {}", fd_2);
+  }
+  else
   {
-    kstd::os::panic("demo failed");
+    kapi::system::panic("demo failed");
   }
 
   // 6) read from the new file
   kstd::vector<std::byte> buffer_2{10};
   bytes_read = kapi::filesystem::read(fd_2, buffer_2.data(), buffer_2.size());
   buffer_as_str = std::string_view{reinterpret_cast<char *>(buffer_2.data()), static_cast<size_t>(bytes_read)};
-  kstd::println("Read {} bytes from /entrance/information/info_1.txt: {}", bytes_read, buffer_as_str);
+  kstd::println("--> read {} bytes from /entrance/information/info_1.txt: {} ", bytes_read, buffer_as_str);
 
   // 7) open device as file
-  auto fd_3 = kapi::filesystem::open("/dev/ram48");
-  if (fd_3 == -1)
+  kstd::println("attempting to open /dev/ram32 as a file");
+  auto fd_3 = kapi::filesystem::open("/dev/ram32");
+  if (fd_3 != -1)
+  {
+    kstd::println("--> successfully opened /dev/ram32 as a file with file descriptor {}", fd_3);
+  }
+  else
   {
-    kstd::os::panic("demo failed");
+    kapi::system::panic("demo failed");
   }
 
   // 8) read from the device file
   kstd::vector<std::byte> buffer_3{2};
   bytes_read = kapi::filesystem::read(fd_3, buffer_3.data(), buffer_3.size());
-  kstd::println("Read {} bytes from /dev/ram48: {::#04x}", bytes_read, buffer_3);
+  kstd::println("--> read {} bytes from /dev/ram32: {::#04x} ", bytes_read, buffer_3);
 
   // 9) write to the device file
-  kstd::vector<std::byte> write_buffer{std::byte{0xAA}, std::byte{0xAA}};
+  auto const default_buffer_value = std::byte{0xAA};
+  kstd::vector<std::byte> write_buffer{default_buffer_value, default_buffer_value};
   auto bytes_written = kapi::filesystem::write(fd_3, write_buffer.data(), write_buffer.size());
-  kstd::println("Written {} bytes to /dev/ram48: {::#04x}", bytes_written, write_buffer);
+  kstd::println("--> written {} bytes to /dev/ram32: {::#04x}", bytes_written, write_buffer);
 
   // 10) do memory dump to show that the write to the device file had an effect
 }