Implement utime() along with a naive /bin/touch.

This synchronous approach to inodes is silly, obviously. I need to rework
it so that the in-memory CoreInode object is the canonical inode, and then
we just need a sync() that flushes pending changes to disk.

VirtualFileSystem/Ext2FileSystem.cpp

@@ -716,16 +716,18 @@ bool Ext2FS::modify_link_count(InodeIndex inode, int delta)
     return write_ext2_inode(inode, *e2inode);
 }
 
-bool Ext2FS::set_mtime(InodeIdentifier inode, dword timestamp)
+int Ext2FS::set_atime_and_mtime(InodeIdentifier inode, dword atime, dword mtime)
 {
     ASSERT(inode.fsid() == id());
 
     auto e2inode = lookup_ext2_inode(inode.index());
     if (!e2inode)
-        return false;
+        return -EIO;
 
-    kprintf("changing inode %u mtime from %u to %u\n", inode.index(), e2inode->i_mtime, timestamp);
-    e2inode->i_mtime = timestamp;
+    dbgprintf("changing inode %u atime from %u to %u\n", inode.index(), e2inode->i_atime, atime);
+    dbgprintf("changing inode %u mtime from %u to %u\n", inode.index(), e2inode->i_mtime, mtime);
+    e2inode->i_mtime = mtime;
+    e2inode->i_atime = atime;
 
     return write_ext2_inode(inode.index(), *e2inode);
 }

VirtualFileSystem/Ext2FileSystem.h

@@ -72,7 +72,7 @@ private:
     virtual InodeIdentifier root_inode() const override;
     virtual bool write_inode(InodeIdentifier, const ByteBuffer&) override;
     virtual InodeMetadata inode_metadata(InodeIdentifier) const override;
-    virtual bool set_mtime(InodeIdentifier, dword timestamp) override;
+    virtual int set_atime_and_mtime(InodeIdentifier, dword atime, dword mtime) override;
     virtual InodeIdentifier create_inode(InodeIdentifier parentInode, const String& name, Unix::mode_t, unsigned size, int& error) override;
     virtual ssize_t read_inode_bytes(InodeIdentifier, Unix::off_t offset, size_t count, byte* buffer, FileDescriptor*) const override;
     virtual InodeIdentifier create_directory(InodeIdentifier parentInode, const String& name, Unix::mode_t, int& error) override;

VirtualFileSystem/FileDescriptor.cpp

@@ -288,3 +288,17 @@ FileDescriptor::FileDescriptor(FIFO& fifo, FIFO::Direction direction)
 {
     m_fifo->open(direction);
 }
+
+int FileDescriptor::set_atime_and_mtime(time_t atime, time_t mtime)
+{
+    if (!m_vnode || !m_vnode->core_inode())
+        return -EBADF;
+    return m_vnode->core_inode()->set_atime_and_mtime(atime, mtime);
+}
+
+int FileDescriptor::set_ctime(time_t ctime)
+{
+    (void) ctime;
+    // FIXME: Implement.
+    ASSERT_NOT_REACHED();
+}

VirtualFileSystem/FileDescriptor.h

@@ -64,13 +64,15 @@ public:
 
     ByteBuffer& generator_cache() { return m_generator_cache; }
 
+    int set_atime_and_mtime(time_t, time_t);
+    int set_ctime(time_t);
+
 private:
     friend class VFS;
     explicit FileDescriptor(RetainPtr<Vnode>&&);
     FileDescriptor(FIFO&, FIFO::Direction);
 
     RetainPtr<Vnode> m_vnode;
-    RetainPtr<CoreInode> m_inode;
 
     Unix::off_t m_current_offset { 0 };
 

VirtualFileSystem/FileSystem.cpp

@@ -127,3 +127,8 @@ FS::DirectoryEntry::DirectoryEntry(const char* n, size_t nl, InodeIdentifier i,
 CoreInode::~CoreInode()
 {
 }
+
+int CoreInode::set_atime_and_mtime(Unix::time_t atime, Unix::time_t mtime)
+{
+    return fs().set_atime_and_mtime(identifier(), atime, mtime);
+}

VirtualFileSystem/FileSystem.h

@@ -44,7 +44,7 @@ public:
         byte fileType { 0 };
     };
 
-    virtual bool set_mtime(InodeIdentifier, dword timestamp) = 0;
+    virtual int set_atime_and_mtime(InodeIdentifier, dword atime, dword mtime) = 0;
     virtual InodeIdentifier create_inode(InodeIdentifier parentInode, const String& name, Unix::mode_t, unsigned size, int& error) = 0;
     virtual InodeIdentifier create_directory(InodeIdentifier parentInode, const String& name, Unix::mode_t, int& error) = 0;
 
@@ -85,6 +85,8 @@ public:
     virtual InodeIdentifier lookup(const String& name) = 0;
     virtual String reverse_lookup(InodeIdentifier) = 0;
 
+    int set_atime_and_mtime(Unix::time_t atime, Unix::time_t mtime);
+
 protected:
     CoreInode(FS& fs, unsigned index)
         : m_fs(fs)

VirtualFileSystem/SyntheticFileSystem.cpp

@@ -146,11 +146,12 @@ InodeMetadata SynthFS::inode_metadata(InodeIdentifier inode) const
     return (*it).value->m_metadata;
 }
 
-bool SynthFS::set_mtime(InodeIdentifier, dword timestamp)
+int SynthFS::set_atime_and_mtime(InodeIdentifier, dword atime, dword mtime)
 {
-    (void) timestamp;
+    (void) atime;
+    (void) mtime;
     kprintf("FIXME: Implement SyntheticFileSystem::setModificationTime().\n");
-    return false;
+    return -ENOTIMPL;
 }
 
 InodeIdentifier SynthFS::create_inode(InodeIdentifier parentInode, const String& name, Unix::mode_t mode, unsigned size, int& error)

VirtualFileSystem/SyntheticFileSystem.h

@@ -16,7 +16,7 @@ public:
     virtual InodeIdentifier root_inode() const override;
     virtual bool write_inode(InodeIdentifier, const ByteBuffer&) override;
     virtual InodeMetadata inode_metadata(InodeIdentifier) const override;
-    virtual bool set_mtime(InodeIdentifier, dword timestamp) override;
+    virtual int set_atime_and_mtime(InodeIdentifier, dword atime, dword mtime) override;
     virtual InodeIdentifier create_inode(InodeIdentifier parentInode, const String& name, Unix::mode_t, unsigned size, int& error) override;
     virtual ssize_t read_inode_bytes(InodeIdentifier, Unix::off_t offset, size_t count, byte* buffer, FileDescriptor*) const override;
     virtual InodeIdentifier create_directory(InodeIdentifier parentInode, const String& name, Unix::mode_t, int& error) override;

VirtualFileSystem/UnixTypes.h

@@ -264,6 +264,11 @@ typedef signed_qword off_t;
 typedef ::time_t time_t;
 #endif
 
+struct utimbuf {
+    time_t actime;
+    time_t modtime;
+};
+
 typedef dword blksize_t;
 typedef dword blkcnt_t;
 

VirtualFileSystem/VirtualFileSystem.cpp

@@ -252,15 +252,6 @@ void VFS::traverse_directory_inode(CoreInode& dir_inode, Function<bool(const FS:
     });
 }
 
-bool VFS::touch(const String& path)
-{
-    int error;
-    auto inode = resolve_path(path, root_inode_id(), error);
-    if (!inode.is_valid())
-        return false;
-    return inode.fs()->set_mtime(inode, ktime(nullptr));
-}
-
 RetainPtr<FileDescriptor> VFS::open(CharacterDevice& device, int options)
 {
     // FIXME: Respect options.