Diffusion 0 A.D. Public Repository rP25104

Make real directory paths on the VFS predictable.
rP25104
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Description

Make real directory paths on the VFS predictable.

Partial revert/fix of rP13167 and rP13472.

Before this diff, it was possible for a mod containing a cache/ or a config/ folder to get written to incorrectly.
The issue is VFS can map multiple directories to one 'virtual' path, for reading mods. However, writing data is problematic: which path to choose?
The only viable solution is to use a path relative to the highest priority directory encountered in the VFS path, or write paths could be 'hijacked' by lower-priority mods.

This fixes these issues by:

Adding a new lookup mode ('Real-path') that explicitly picks the real path relative to the highest-priority subdirectory in the VFS Path.
Preventing overwriting a real directory with a lower priority one in general.
Revert rP8082's GetRealPath change, re-introducing the function as GetOriginalPath.

This also cleans up some duplication that led to empty mod folders in the user mod path, and cleans up loading the 'user' mod.

Note that the new 'realpath' lookup can still be somewhat complex with many mount points at various hierarchy levels, but it is at least predictable/deterministic without having to be careful about populating order.

Fixes #2553

Differential Revision: https://code.wildfiregames.com/D3217

Details

Committed

wraitii

Mar 22 2021, 7:49 PM

Differential Revision

D3217: Fix writing mod data.

Parents

rP25103: Fix AI+Player from persistent settings (again)

Branches

Unknown

Tags

Unknown

Reverts

rP8082: fix VFS real path retrieval for files mounted from multiple directories (e.g.

Reverted By

rP25105: Revert rP25104

Build Status

Buildable 16340
Build 36761: Trigger Windows Autobuild
Build 36760: Post-Commit Build	Jenkins
Build 36759: Post-Commit Build (macOS)	Jenkins

Event Timeline

wraitii committed rP25104: Make real directory paths on the VFS predictable..Mar 22 2021, 7:49 PM

wraitii added an edge: D3217: Fix writing mod data..

wraitii added a reverted change: rP8082: fix VFS real path retrieval for files mounted from multiple directories (e.g..

GameSetup.cpp
../../../source/ps/GameSetup/GameSetup.cpp: In function ‘void MountMods(const Paths&, const std::vector<CStr8>&)’:
../../../source/ps/GameSetup/GameSetup.cpp:414:14: warning: ‘priority’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  g_VFS->Mount(L"", modUserPath / "user", userFlags, InDevelopmentCopy() ? 0 : priority + 1);
  ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

mh, also forgot to fix the windows warning I think. Will do tomorrow.

Harbormaster completed building B16340: rP25104: Make real directory paths on the VFS predictable..Mar 22 2021, 8:43 PM

g_VFS->Mount(L"", modUserPath / "user", userFlags, InDevelopmentCopy() ? 0 : priority + 1);

broke

pyrogenesis.exe!DirWatchManager::Add(const Path & path, std::shared_ptr<DirWatch> & dirWatch) Line 311 C++

This commit now has outstanding concerns.Mar 22 2021, 8:44 PM

wraitii added a reverting change: rP25105: Revert rP25104.Mar 22 2021, 8:52 PM

Reverted for now... Gonna have to debug this somehow.

This commit no longer requires audit.Mar 22 2021, 8:53 PM

pyrogenesis.exe!DirWatchManager::Add(const Path & path, std::shared_ptr<DirWatch> & dirWatch) Line 311 C++

	pyrogenesis.exe!dir_watch_Add(const Path & path, std::shared_ptr<DirWatch> & dirWatch) Line 361	C++
	pyrogenesis.exe!RealDirectory::Watch() Line 64	C++
	pyrogenesis.exe!vfs_Populate(VfsDirectory * directory) Line 162	C++
	pyrogenesis.exe!vfs_Attach(VfsDirectory * directory, const std::shared_ptr<RealDirectory> & realDirectory) Line 188	C++
	pyrogenesis.exe!VFS::Mount(const Path & mountPoint, const Path & path, unsigned int flags, unsigned int priority) Line 70	C++
	pyrogenesis.exe!MountMods(const Paths & paths, const std::vector<CStr8,std::allocator<CStr8>> & mods) Line 414	C++
	pyrogenesis.exe!InitVfs(const CmdLineArgs & args, int flags) Line 453	C++
	pyrogenesis.exe!Init(const CmdLineArgs & args, int flags) Line 865	C++
	pyrogenesis.exe!RunGameOrAtlas(int argc, const char * * argv) Line 652	C++
	pyrogenesis.exe!SDL_main(int argc, char * * argv) Line 744	C++

wraitii mentioned this in D3728: D3217 #2 - Make real directory paths on the VFS predictable..Mar 23 2021, 11:27 AM

wraitii mentioned this in rP25107: Make real directory paths on the VFS predictable (retry).Mar 23 2021, 1:47 PM