* perf: answer Steam's missing-file checks on FUSE libraries from the directory cache
Before creating and committing each file, the Steam client checks whether it
already exists under its exact, lower-cased and folded spellings. On an SD or
USB library reached through Android's FUSE layer every one of those misses is a
round trip to MediaProvider (Brawlhalla: about 65,000 misses, 92 of the 161 s
of preallocation and 60 of the 93 s of commit).
The client already caches the listings of its steamapps directories on FUSE and
keeps them exact through its own changes, inotify and a short TTL. access() now
answers a name that is absent from a live listing of its directory without
asking the filesystem. Directory paths match case-insensitively only when the
library's filesystem folds case, and names compare case-insensitively, so an
existing file is never reported missing.
* fix: reuse a listing for a differently cased folder only when the whole path folds case
Checking that steamapps alone folds case let a listing of one folder answer
for a different folder below it whose name differs only in case. The fill
now compares the listed folder with its fully case-swapped path below
steamapps, so a listing is reused across case only when the filesystem
folds every level.
* fix(dircache): match a folded listing only below the same prefix and skip it during a tracked change
* fix(linuxfs): a folder renamed or removed above a cached listing drops that listing
* fix(linuxfs): watch the folders above a cached listing so a rename or removal by any process drops it
* fix(linuxfs): also watch the folders above steamapps, and stop a stuck probe from hanging the tests
* fix(linuxfs): a listing under a symlink or an unwatchable folder no longer answers absent lookups
* fix(linuxfs): a symlink check that cannot be watched also stops absent answers
* fix(linuxfs): a differently cased lookup reuses a listing only for the same folder
An opt-in second Steam client (Steam settings, Steam client: x86-64): Valve's
x86-64 Linux client, unchanged, runs under FEX in its own home with its own
game library and the same sign-in. Linux builds run directly, so titles such
as Team Fortress 2 and Half-Life use their Linux versions; Windows games use
DroidDeck-Proton as on arm64. The arm64 client stays the default.
- droiddeck-steam-x64: FEX and the x86-64 rootfs from DroidDeck-Components
(sha256-pinned), client install and sync from Valve's CDN, sign-in shared
with the arm64 client, its web helper on the GPU (ANGLE GL over FEX's GL
thunk, zink, Turnip), Proton wrappers for the arm64 client's tools,
DroidDeck direct for Linux builds, SD-card library (x86-64/ beside the
arm64 one), repair.
- FEX 2610 built by build-fex.yml with thunks and three patches: an openat2
fallback without openat2 (proot), newer-clang thunkgen, MAP_32BIT
exhaustion returning ENOMEM. libblsession resolves RESOLVE_IN_ROOT paths
inside the root.
- Session: x86-64 gating, shortcuts and compatibility tools per client,
logs from the client that ran.
- App: client setting with the FEX version, an x86-64 chip on the Games
header, the active client's library, art, storage, downloads, repair,
Offline Mode, Decky, desktop mode, optional VAC diagnostics; per-client
state for art, the content log, repair and leftovers.
- Strings in every locale.
- Review fixes: the library cache is saved only by the newest scan; an
abandoned session's Steam logs come from the client it recorded; distinct
VAC console names; FEXInterpreter in CPU pinning; clearer VAC hint in
pl, ru, uk, cs and bg.
* Run programs, scripts and AppImages from the desktop
Windows programs open with the Proton Steam has chosen, and a Steam game's own
launch program is handed to Steam. x86-64 Linux programs and game scripts run
under FEX, and an exec the kernel refuses goes to droiddeck-open through
libblsession's binfmt.c. Programs on noexec shared storage pass KIO's checks; a
folder of Linux programs there, and sharun AppImages, are added by the app once
and run from the copy. Executable scripts run without KIO's prompt, mpv plays
on the software desktop, FEXServer's socket moves under XDG_RUNTIME_DIR, and
Proton runtimes no longer show up as games.
* Switch to Desktop from Big Picture without Deck mode
Big Picture's Switch to Desktop asks the client's SteamOS manager, which the
client only has when started as SteamOS (Deck mode). Without it the request
failed and the screen stayed on "Switching to Desktop..." for good. The live
compat helper now sees the request on its way to the client and hands it to
steamos-session-select, which opens the KDE desktop as Deck mode already did.
* Run x86 programs from shared storage where they lie
FEX asks for the guest's PROT_EXEC when it maps a program or library, which
the kernel refuses on noexec shared storage; FEX never runs those pages
itself, so libblsession maps them without it in FEX's processes. An x86
game, its libraries and its start script now run in place instead of being
copied in; only native code on noexec storage is still copied.
A Steam library's games are never copied, and a Linux game's launch program
opened from the desktop goes to Steam like a Windows one.
MaxsTechReview