Name
erofs - the Enhanced Read-Only File SystemDescription
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 | readaroundCache allocation for compressed files: never, if reading from start of file, regardless of position. Defaults to readaround .
dax dax = always | neverDirect 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 = blobdevAdd 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 = idControl 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.txt in the Linux source.