From 9f9b4a23823a851d632a0b2e757f1232b5de5620 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Sun, 14 Oct 2018 13:16:09 +0200
Subject: [PATCH] Add a simple /dev/full.

---
 VirtualFileSystem/FullDevice.cpp |  30 +++++++++++++++++++++++++
 VirtualFileSystem/FullDevice.h   |  13 +++++++++++
 VirtualFileSystem/Makefile       |   1 +
 VirtualFileSystem/small.fs       | Bin 2048000 -> 2048000 bytes
 VirtualFileSystem/sys-errno.h    |  37 +++++++++++++++++++++++++++++++
 VirtualFileSystem/test.cpp       |   4 ++++
 6 files changed, 85 insertions(+)
 create mode 100644 VirtualFileSystem/FullDevice.cpp
 create mode 100644 VirtualFileSystem/FullDevice.h
 create mode 100644 VirtualFileSystem/sys-errno.h

diff --git a/VirtualFileSystem/FullDevice.cpp b/VirtualFileSystem/FullDevice.cpp
new file mode 100644
index 0000000000..2ef60e6299
--- /dev/null
+++ b/VirtualFileSystem/FullDevice.cpp
@@ -0,0 +1,30 @@
+#include "FullDevice.h"
+#include "Limits.h"
+#include "sys-errno.h"
+#include <AK/StdLib.h>
+#include <cstring>
+#include <cstdio>
+
+FullDevice::FullDevice()
+{
+}
+
+FullDevice::~FullDevice()
+{
+}
+
+ssize_t FullDevice::read(byte* buffer, size_t bufferSize)
+{
+    printf("read from full device\n");
+    size_t count = min(GoodBufferSize, bufferSize);
+    memset(buffer, 0, count);
+    return count;
+}
+
+ssize_t FullDevice::write(const byte*, size_t bufferSize)
+{
+    if (bufferSize == 0)
+        return 0;
+    return -ENOSPC;
+}
+
diff --git a/VirtualFileSystem/FullDevice.h b/VirtualFileSystem/FullDevice.h
new file mode 100644
index 0000000000..ca1743270a
--- /dev/null
+++ b/VirtualFileSystem/FullDevice.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include "CharacterDevice.h"
+
+class FullDevice final : public CharacterDevice {
+public:
+    FullDevice();
+    virtual ~FullDevice();
+
+    ssize_t read(byte* buffer, size_t bufferSize) override;
+    ssize_t write(const byte* buffer, size_t bufferSize) override;
+};
+
diff --git a/VirtualFileSystem/Makefile b/VirtualFileSystem/Makefile
index 035039a658..7b3df94bb4 100644
--- a/VirtualFileSystem/Makefile
+++ b/VirtualFileSystem/Makefile
@@ -21,6 +21,7 @@ VFS_OBJS = \
     CharacterDevice.o \
     ZeroDevice.o \
     NullDevice.o \
+    FullDevice.o \
     test.o
 
 OBJS = $(AK_OBJS) $(VFS_OBJS)
diff --git a/VirtualFileSystem/small.fs b/VirtualFileSystem/small.fs
index 2970765b7362bfc2b945e5546d2ba4f57c11cc3f..0eb8186ea16e243f596bf391fa166eaa34319f0e 100644
GIT binary patch
delta 236
zcmZo@sBLJd-5|ii_-L{qi#)4@%He3H&893jnHe8#=I8jL%xFK6QD(D(PNIOOA_Eu*
zs~nDoVXy!LBZPvI?2Ho`tysGKWiC!+l$hLLz`-qo(6L$AR`jw64+9HxRccYb6axdp
z1!flJw9=fMjf_W_+e8@KM3~w{nA=2H+C*5}MA+Iy*xN)n+C(_pM7Y{SxZ6Z{+C+HU
zMEKf7_}fGT+C&7~M1<Nzgxf?!+C)U#M8w)e#M?w9+C(JVM5Nk8q}xPf+C*gAMC6u<
H$m;+AJ^D8m

delta 194
zcmZo@sBLJd-5|ii_;|7)i#)6J)I-sXn@w46GBZBj%+K*fnbCG4qs(RnokRigMg}nW
zG38LS*wjPOFnS_m#^eSA9(KX0hoS|i9@;EyD|(sZ4l@gLRccZGM#c-wZ6b_qB1~-}
z%xxkpZ6d5~B5Z9U>}?_(Z6cg)B3x}E+-)K}Z6dsFB7AKk{B0rvZ6bngB0_B<!fhfV
mZ6cy=B4TYK;%y=lZ6cCwB2sN4(rqF#Z6dO5B67<_<aGd#+Bh2k

diff --git a/VirtualFileSystem/sys-errno.h b/VirtualFileSystem/sys-errno.h
new file mode 100644
index 0000000000..2c11307a0d
--- /dev/null
+++ b/VirtualFileSystem/sys-errno.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#define EPERM    1    // Operation not permitted
+#define ENOENT   2    // No such file or directory
+#define ESRCH    3    // No such process
+#define EINTR    4    // Interrupted system call
+#define EIO      5    // I/O error
+#define ENXIO    6    // No such device or address
+#define E2BIG    7    // Argument list too long
+#define ENOEXEC  8    // Exec format error
+#define EBADF    9    // Bad file number
+#define ECHILD  10    // No child processes
+#define EAGAIN  11    // Try again
+#define ENOMEM  12    // Out of memory
+#define EACCES  13    // Permission denied
+#define EFAULT  14    // Bad address
+#define ENOTBLK 15    // Block device required
+#define EBUSY   16    // Device or resource busy
+#define EEXIST  17    // File exists
+#define EXDEV   18    // Cross-device link
+#define ENODEV  19    // No such device
+#define ENOTDIR 20    // Not a directory
+#define EISDIR  21    // Is a directory
+#define EINVAL  22    // Invalid argument
+#define ENFILE  23    // File table overflow
+#define EMFILE  24    // Too many open files
+#define ENOTTY  25    // Not a typewriter
+#define ETXTBSY 26    // Text file busy
+#define EFBIG   27    // File too large
+#define ENOSPC  28    // No space left on device
+#define ESPIPE  29    // Illegal seek
+#define EROFS   30    // Read-only file system
+#define EMLINK  31    // Too many links
+#define EPIPE   32    // Broken pipe
+#define EDOM    33    // Math argument out of domain of func
+#define ERANGE  34    // Math result not representable
+
diff --git a/VirtualFileSystem/test.cpp b/VirtualFileSystem/test.cpp
index e7ff504563..c7183611ee 100644
--- a/VirtualFileSystem/test.cpp
+++ b/VirtualFileSystem/test.cpp
@@ -5,6 +5,7 @@
 #include "SyntheticFileSystem.h"
 #include "ZeroDevice.h"
 #include "NullDevice.h"
+#include "FullDevice.h"
 #include <cstring>
 #include <AK/SimpleMalloc.h>
 #include <AK/kmalloc.h>
@@ -25,6 +26,9 @@ int main(int c, char** v)
     auto null = make<NullDevice>();
     vfs.registerCharacterDevice(1, 3, *null);
 
+    auto full = make<FullDevice>();
+    vfs.registerCharacterDevice(1, 7, *full);
+
     if (!vfs.mountRoot(makeFileSystem(filename))) {
         printf("Failed to mount root :(\n");
         return 1;