btrfs-fuse 0.13.0

Userspace FUSE driver for btrfs, built on btrfs-disk.
Documentation 
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//! Argument types for the `btrfs-fuse` mount entry point.
//!
//! Mirrors the `mkfs` / `tune` split: the clap-derived [`MountArgs`]
//! struct lives here in the library so the standalone `btrfs-fuse`
//! binary, the embedded `btrfs fuse` subcommand in `btrfs-cli`, and
//! any other front-end can share a single source of truth for the
//! flags. The actual mount logic lives in [`crate::run::run_mount`].

use clap::Parser;
use std::path::PathBuf;

/// Mount a btrfs image or block device read-only via FUSE.
#[derive(Parser, Debug, Clone)]
#[command(version, arg_required_else_help = true, max_term_width = 100)]
pub struct MountArgs {
    /// Path to the btrfs image file or block device.
    pub image: PathBuf,
    /// Mount point.
    pub mountpoint: PathBuf,
    /// Run in the foreground (do not daemonize).
    #[arg(short = 'f', long)]
    pub foreground: bool,
    /// Allow other users to access the mount.
    #[arg(long)]
    pub allow_other: bool,
    /// Mount the named subvolume as the root of the FUSE filesystem.
    ///
    /// The path is interpreted relative to the filesystem root, e.g.
    /// `--subvol home/snapshots/2025-01-01`. Mutually exclusive with
    /// `--subvolid`.
    #[arg(long)]
    pub subvol: Option<String>,
    /// Mount the subvolume with this tree id.
    ///
    /// Use the value reported by `btrfs subvolume list`. Mutually
    /// exclusive with `--subvol`.
    #[arg(long, conflicts_with = "subvol")]
    pub subvolid: Option<u64>,
    /// Don't ask the kernel to enforce file mode/uid/gid permissions
    /// against the calling user.
    ///
    /// By default the FUSE mount uses
    /// `default_permissions` so a non-root mounter can't read root-
    /// owned files in the image — matching kernel btrfs semantics.
    /// Pass this flag to bypass that check, e.g. when inspecting an
    /// image whose stored ownership doesn't match your local UIDs.
    #[arg(long)]
    pub no_default_permissions: bool,
    /// Number of tree blocks to cache (~16 KiB each).
    ///
    /// Set to 1 to effectively disable; large values trade RAM for fewer disk
    /// reads on tree walks.
    #[arg(long, default_value_t = 4096)]
    pub cache_tree_blocks: usize,
    /// Number of parsed inode items to cache.
    #[arg(long, default_value_t = 4096)]
    pub cache_inodes: usize,
    /// Number of per-inode extent maps to cache.
    ///
    /// Each map is one entry per `EXTENT_DATA` item in the file.
    #[arg(long, default_value_t = 1024)]
    pub cache_extent_maps: usize,
}