hesela.devRead-only mount
A read-only mount restricts filesystem modification through Linux mount state, whose scope can be a VFS mount node, the filesystem superblock, or both.
The util-linux v2.41.1 manual distinguishes both layers: a requested ro setting applies to both layers by default for standard mounts, but a read-only bind mount can leave another path writable. [1] Btrfs may still replay its recovery log during a read-only mount. [2] Since util-linux 2.41, optional ro=vfs and ro=fs arguments can select a layer; the v2.41.1 manual marks them experimental and requires the file-descriptor-based mount API. The old mount(2) interface silently ignores the optional argument. [1]
Relations
- related
- btrfs-read-only-subvolume, block-device-read-only, btrfs-tree-log
Limitations
- Read-only access through one path does not establish that the underlying device was unchanged. [1, 2]
- The requested option spelling alone does not verify the effective layer; findmnt can report VFS-OPTIONS and FS-OPTIONS separately, but those flags are not an audit of device writes. [1]