erofs - the Enhanced Read-Only File System

Linux must be configured with the CONFIG_EROFS_FS option to mount EROFS filesystems. There are sub- configuration items that restrict the availability of some of the parameters above.

erofs is a create-once read-only filesystem, with support for compression and a multi-device backing store. There are two inode formats: • 32-byte compact with 16-bit UID/GID, 32-bit file size, and no file times • 64-byte extended with 32-bit UID/GID, 64-bit file size, and a modification time (st_mtim). Mountoptionsuser_xattrnouser_xattr Controls whether user extended attributes are exposed. Defaults to yes. aclnoacl Controls whether POSIX acl(5)s are exposed. Defaults to yes. cache_strategy=disabled|readahead|readaround Cache allocation for compressed files: never, if reading from start of file, regardless of position. Defaults to readaround. daxdax=always|never Direct Access control. If always and the source device supports DAX, uncompressed non-inlined files will be read directly, without going through the page cache. dax is a synonym for always. Defaults to unset, which is equivalent to never. device=blobdev Add extra device holding some of the data. Must be given as many times and in the same order as --blobdev was to mkfs.erofs(1). domain_id=didfsid=id Control CacheFiles on-demand read support. To be documented.

erofs - the Enhanced Read-Only File System

mkfs.erofs(1), fsck.erofs(1), dump.erofs(1) Documentation/filesystems/erofs.txt in the Linux source. Linux man-pages 6.9.1 2024-05-02 erofs(5)

erofs images are versioned through the use of feature flags; these are listed in the -E section of mkfs.erofs(1),