Kernel/VFS: Make filesystem implementations responsible for renames

Previously, the VFS layer would try to handle renames more-or-less by
itself, which really only worked for ext2, and even that was only due to
the replace_child kludge existing specifically for this purpose. This
never worked properly for FATFS, since the VFS layer effectively
depended on filesystems having some kind of reference-counting for
inodes, which is something that simply doesn't exist on any FAT variant
we support.

To resolve various issues with the existing scheme, this commit makes
filesystem implementations themselves responsible for the actual rename
operation, while keeping all the existing validation inside the VFS
layer. The only intended behavior change here is that rename operations
should actually properly work on FATFS.
This commit is contained in:
implicitfield
2024-12-01 23:29:16 +02:00
committed by Nico Weber
parent 666ba3b970
commit 0e94887b2c
42 changed files with 192 additions and 144 deletions

View File

@@ -812,18 +812,9 @@ ErrorOr<void> VirtualFileSystem::rename(VFSRootContext const& vfs_root_context,
}
if (new_inode.is_directory() && !old_inode.is_directory())
return EISDIR;
TRY(new_parent_inode.remove_child(new_basename));
}
TRY(new_parent_inode.add_child(old_inode, new_basename, old_inode.mode()));
TRY(old_parent_inode.remove_child(old_basename));
// If the inode that we moved is a directory and we changed parent
// directories, then we also have to make .. point to the new parent inode,
// because .. is its own inode.
if (old_inode.is_directory() && old_parent_inode.index() != new_parent_inode.index()) {
TRY(old_inode.replace_child(".."sv, new_parent_inode));
}
TRY(new_parent_inode.fs().rename(old_parent_inode, old_basename, new_parent_inode, new_basename));
return {};
}