erofs(5)

NAME
erofs - the Enhanced Read-Only File System

DESCRIPTION
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).

  Mount options

user_xattr
nouser_xattr
    Controls whether user extended attributes are exposed. Defaults to yes.

acl
noacl
    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.

dax
dax=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=did
fsid=id
    Control CacheFiles on-demand read support. To be documented.

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

CONFIGURATION
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.

SEE ALSO
mkfs.erofs(1), fsck.erofs(1), dump.erofs(1)

Documentation/filesystems/erofs.rst in the Linux source.