Linux: Fix nw fs detection + a few fixes

- Fix network filesystem detection
- Filter snap loopback mounts and other system internals from Linux volume list
- Scroll highlighted volume into view during keyboard navigation
- Fix volume dropdown clipping by calculating max-height from actual viewport position

Author: vdavid

apps/desktop/src-tauri/src/file_system/linux_mounts.rs

@@ -91,11 +91,22 @@ pub fn is_network_filesystem_linux(path: &Path) -> bool {
 }
 
 /// Returns true if the filesystem type string represents a network filesystem.
+///
+/// Known network types are matched explicitly. Unknown `fuse.*` subtypes are
+/// treated conservatively as network (we can't distinguish `fuse.mycloud`
+/// from a local FUSE mount, and chunked copy is the safer default).
 pub fn is_network_fs_type(fstype: &str) -> bool {
-    matches!(
-        fstype,
-        "nfs" | "nfs4" | "cifs" | "smbfs" | "fuse.sshfs" | "ncpfs" | "9p"
-    )
+    match fstype {
+        // Kernel-native network filesystems
+        "nfs" | "nfs4" | "cifs" | "smbfs" | "ncpfs" | "9p" | "afs" => true,
+        // FUSE-based network filesystems
+        "fuse.sshfs" | "fuse.rclone" | "fuse.s3fs" | "fuse.gvfsd-fuse" => true,
+        // FUSE-based local filesystems (known safe)
+        "fuse.ntfs-3g" | "fuse.exfat" | "fuseblk" => false,
+        // Unknown FUSE subtypes — could be network, use chunked copy to be safe
+        s if s.starts_with("fuse.") => true,
+        _ => false,
+    }
 }
 
 /// Unescapes octal sequences in mount paths (for example, `\040` -> space).
@@ -180,11 +191,30 @@ user@host:/path /mnt/sshfs fuse.sshfs rw,relatime 0 0
 
     #[test]
     fn test_is_network_fs_type() {
+        // Kernel-native network filesystems
         assert!(is_network_fs_type("nfs"));
         assert!(is_network_fs_type("nfs4"));
         assert!(is_network_fs_type("cifs"));
         assert!(is_network_fs_type("smbfs"));
+        assert!(is_network_fs_type("ncpfs"));
+        assert!(is_network_fs_type("9p"));
+        assert!(is_network_fs_type("afs"));
+
+        // FUSE-based network filesystems
         assert!(is_network_fs_type("fuse.sshfs"));
+        assert!(is_network_fs_type("fuse.rclone"));
+        assert!(is_network_fs_type("fuse.s3fs"));
+        assert!(is_network_fs_type("fuse.gvfsd-fuse"));
+
+        // Unknown FUSE subtypes — conservatively treated as network
+        assert!(is_network_fs_type("fuse.mycloud"));
+
+        // Known-local FUSE types
+        assert!(!is_network_fs_type("fuse.ntfs-3g"));
+        assert!(!is_network_fs_type("fuse.exfat"));
+        assert!(!is_network_fs_type("fuseblk"));
+
+        // Local filesystems
         assert!(!is_network_fs_type("ext4"));
         assert!(!is_network_fs_type("xfs"));
         assert!(!is_network_fs_type("btrfs"));

apps/desktop/src-tauri/src/volumes_linux/mod.rs

@@ -91,9 +91,14 @@ const VIRTUAL_FS_TYPES: &[&str] = &[
 pub fn supports_trash_for_fs_type(fs_type: Option<&str>) -> bool {
     let Some(fs) = fs_type else { return true };
     let fs_lower = fs.to_ascii_lowercase();
+
+    // Network filesystems don't support the FreeDesktop trash spec
+    if linux_mounts::is_network_fs_type(&fs_lower) {
+        return false;
+    }
+
     match fs_lower.as_str() {
         "ext4" | "ext3" | "ext2" | "btrfs" | "xfs" | "zfs" | "f2fs" | "reiserfs" => true,
-        "nfs" | "nfs4" | "cifs" | "smbfs" | "fuse.sshfs" | "ncpfs" | "9p" => false,
         "vfat" | "exfat" | "msdos" | "ntfs" | "fuseblk" => false,
         _ => true,
     }
@@ -213,6 +218,9 @@ pub fn get_mounted_volumes(mounts: &[MountEntry]) -> Vec<LocationInfo> {
         if entry.mountpoint == "/" {
             continue;
         }
+        if is_hidden_mount(&entry.mountpoint) {
+            continue;
+        }
 
         let is_removable = is_removable_mount(&entry.mountpoint, &username);
         let name = mount_display_name(&entry.mountpoint);
@@ -326,6 +334,21 @@ fn is_virtual_fs(fstype: &str) -> bool {
     VIRTUAL_FS_TYPES.contains(&fstype)
 }
 
+/// Mount paths that are system internals and should never appear as volumes.
+/// These are path prefixes — any mount whose mountpoint starts with one of these is filtered out.
+const HIDDEN_MOUNT_PREFIXES: &[&str] = &[
+    "/snap/",          // Ubuntu snap loopback packages (squashfs)
+    "/run/snapd/",     // Snap daemon internals
+    "/boot/",          // EFI system partition, boot loaders
+    "/run/user/",      // Per-user runtime mounts (XDG portals, GVFS)
+    "/run/credentials/", // systemd credential mounts
+];
+
+/// Check if a mount path should be hidden from the volume list.
+fn is_hidden_mount(mountpoint: &str) -> bool {
+    HIDDEN_MOUNT_PREFIXES.iter().any(|prefix| mountpoint.starts_with(prefix))
+}
+
 /// Check if a mount point is under a removable media path.
 fn is_removable_mount(mountpoint: &str, username: &str) -> bool {
     if username.is_empty() {
@@ -429,6 +452,43 @@ tmpfs /tmp tmpfs rw,nosuid,nodev 0 0
         assert!(supports_trash_for_fs_type(Some("somefs")));
     }
 
+    #[test]
+    fn test_is_hidden_mount() {
+        assert!(is_hidden_mount("/snap/firefox/7764"));
+        assert!(is_hidden_mount("/snap/core22/2134"));
+        assert!(is_hidden_mount("/run/snapd/ns/something.mnt"));
+        assert!(is_hidden_mount("/boot/efi"));
+        assert!(is_hidden_mount("/run/user/1000/doc"));
+        assert!(is_hidden_mount("/run/user/1000/gvfs"));
+        assert!(is_hidden_mount("/run/credentials/systemd-journald.service"));
+        assert!(!is_hidden_mount("/mnt/data"));
+        assert!(!is_hidden_mount("/home"));
+        assert!(!is_hidden_mount("/media/user/USB"));
+        assert!(!is_hidden_mount("/run/media/user/USB"));
+    }
+
+    #[test]
+    fn test_snap_mounts_filtered_from_volumes() {
+        let mounts_with_snaps = "\
+/dev/sda1 / ext4 rw,relatime 0 0
+/dev/loop0 /snap/bare/5 squashfs ro,nodev,relatime 0 0
+/dev/loop2 /snap/firefox/7764 squashfs ro,nodev,relatime 0 0
+/dev/loop8 /snap/snap-store/1271 squashfs ro,nodev,relatime 0 0
+/dev/sdb1 /mnt/data xfs rw,relatime 0 0
+tmpfs /run/user/1000 tmpfs rw,nosuid,nodev,relatime 0 0
+portal /run/user/1000/doc fuse.portal rw 0 0
+gvfsd-fuse /run/user/1000/gvfs fuse.gvfsd-fuse rw 0 0
+/dev/vda1 /boot/efi vfat rw,relatime 0 0
+";
+        let mounts = linux_mounts::parse_proc_mounts_from_content(mounts_with_snaps);
+        let volumes = get_mounted_volumes(&mounts);
+        let paths: Vec<&str> = volumes.iter().map(|v| v.path.as_str()).collect();
+        assert!(paths.contains(&"/mnt/data"), "Should include real mount");
+        assert!(!paths.iter().any(|p| p.starts_with("/snap/")), "Should filter snap mounts");
+        assert!(!paths.iter().any(|p| p.starts_with("/boot/")), "Should filter boot mounts");
+        assert!(!paths.iter().any(|p| p.starts_with("/run/user/")), "Should filter user runtime mounts");
+    }
+
     #[test]
     fn test_get_mounted_volumes_filters_virtual() {
         let mounts = parse_test_mounts();

apps/desktop/src/lib/file-explorer/navigation/VolumeBreadcrumb.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-    import { onMount, onDestroy } from 'svelte'
+    import { onMount, onDestroy, tick } from 'svelte'
     import { listVolumes, findContainingVolume, listen, type UnlistenFn } from '$lib/tauri-commands'
     import { getVolumeSpace, type VolumeSpaceInfo } from '$lib/tauri-commands/storage'
     import { SvelteMap } from 'svelte/reactivity'
@@ -70,18 +70,28 @@
     // Flat list of all volumes for keyboard navigation
     const allVolumes = $derived(groupedVolumes.flatMap((g) => g.items))
 
-    // When dropdown opens, initialize highlight to current volume
+    // When dropdown opens, initialize highlight to current volume and fit to viewport
     $effect(() => {
         if (isOpen) {
             const currentIdx = allVolumes.findIndex((v) => shouldShowCheckmark(v))
             highlightedIndex = currentIdx >= 0 ? currentIdx : 0
+            void fitDropdownToViewport()
         } else {
             highlightedIndex = -1
             isKeyboardMode = false
             lastMousePos = null
         }
     })
 
+    async function fitDropdownToViewport() {
+        await tick()
+        const dropdown = dropdownRef?.querySelector('.volume-dropdown') as HTMLElement | null
+        if (dropdown) {
+            const top = dropdown.getBoundingClientRect().top
+            dropdown.style.maxHeight = `${window.innerHeight - top - 8}px`
+        }
+    }
+
     // Get appropriate icon for a volume (use cloud icon for cloud drives, mobile icon for devices)
     function getIconForVolume(volume: VolumeInfo | undefined): string | undefined {
         if (!volume) return undefined
@@ -268,6 +278,13 @@
     function enterKeyboardMode() {
         isKeyboardMode = true
         lastMousePos = null // Will be captured on next mousemove
+        void scrollHighlightedIntoView()
+    }
+
+    async function scrollHighlightedIntoView() {
+        await tick()
+        const el = dropdownRef?.querySelector(`.volume-item[data-index="${highlightedIndex}"]`) as HTMLElement | null
+        el?.scrollIntoView({ block: 'nearest' })
     }
 
     // Handle mouse hover to sync with keyboard navigation
@@ -562,7 +579,7 @@
         left: 0;
         margin-top: 4px;
         min-width: 220px;
-        max-height: calc(100vh - 30px);
+        max-height: calc(100vh - 30px); /* Fallback — overridden dynamically by fitDropdownToViewport() */
         overflow-y: auto;
         background-color: var(--color-bg-secondary);
         border: 1px solid var(--color-border-strong);

docs/specs/linux-remaining-gaps.md

@@ -16,13 +16,13 @@ Each section is self-contained and can be handed to an agent independently.
 - [x] 6. Linux-specific error messages (small) — audit and replace macOS terminology
 - [x] 7. Credential storage resilience (medium) — Secret Service → keyutils → encrypted file fallback
 - [-] 8. ~~Media eject — deferred (not on macOS either)~~
-- [ ] 9. High-DPI support — no code changes needed, just verification
-- [ ] 10. Trash implementation (medium) — `trash` crate, wire up in lib.rs
-- [ ] 11. Network filesystem detection for copy (medium) — `/proc/self/mountinfo` parser, copy strategy
+- [x] 9. High-DPI support — no code changes needed, just verification
+- [x] 10. Trash implementation (medium) — `trash` crate, wire up in lib.rs
+- [x] 11. Network filesystem detection for copy (medium) — `/proc/self/mountinfo` parser, copy strategy
 - [x] 12. File watching E2E verification (small) — add inotify E2E test
 - [ ] 13. MTP USB permissions (small) — error messages + packaging metadata
 - [ ] 14. SMB mounting completion (large) — `smbclient` fallback, auth prompts, cross-DE testing
-- [ ] 15. Custom drag image — deferred (no WebKitGTK API)
+- [-] 15. Custom drag image — deferred (no WebKitGTK API)
 - [ ] 16. Dropbox sync status (medium) — socket protocol + CLI fallback
 - [ ] 17. Native file icons (medium) — test existing provider, fix threading if needed