eliott/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity synced 2026-04-26 01:25:22 +02:00
Code Issues Packages Projects Releases Wiki Activity

Kernel+Userland: Introduce the copy_mount syscall

Browse Source 
This new syscall will be used by the upcoming runc (run-container)
utility.

In addition to that, this syscall allows userspace to neatly copy RAMFS
instances to other places, which was not possible in the past.
This commit is contained in:
Liav A.
2024-01-27 19:36:26 +02:00
committed by Tim Schumacher
parent 816f2efb4e
commit 4370bbb3ad
8 changed files with 105 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
Kernel/FileSystem/VirtualFileSystem.cpp
View File

@@ -202,6 +202,25 @@ ErrorOr<void> VirtualFileSystem::mount(VFSRootContext& context, MountFile& mount
});
}
ErrorOr<void> VirtualFileSystem::copy_mount(Custody& original_custody, VFSRootContext& destination_context, Custody& new_mount_point, int flags)
{
// NOTE: Don't allow moving mounts of inode which are not the root inode
// of a filesystem. This will prevent copying bindmounts, but the intention
// of this functionality was never to allow such thing.
if (&original_custody.inode() != &original_custody.inode().fs().root_inode())
return EINVAL;
// NOTE: If the user specified the root custody ("/") on the destination context
// then try to `pivot_root` the destination context root mount with the desired
// custody.
auto destination_context_root_custody = destination_context.root_custody().with([](auto& custody) -> NonnullRefPtr<Custody> { return custody; });
if (&new_mount_point == destination_context_root_custody.ptr())
return pivot_root_by_copying_mounted_fs_instance(destination_context, original_custody.inode().fs(), flags);
TRY(destination_context.add_new_mount(VFSRootContext::DoBindMount::No, original_custody.inode(), new_mount_point, flags));
return {};
}
ErrorOr<void> VirtualFileSystem::bind_mount(VFSRootContext& context, Custody& source, Custody& mount_point, int flags)
{
return context.add_new_mount(VFSRootContext::DoBindMount::Yes, source.inode(), mount_point, flags);