1 .\" Copyright (c) 2016 by Michael Kerrisk <mtk.manpages@gmail.com>
3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
5 .TH erofs 5 (date) "Linux man-pages (unreleased)"
7 erofs \- the Enhanced Read-Only File System
10 is a create-once read-only filesystem,
11 with support for compression and a multi-device backing store.
13 There are two inode formats:
15 32-byte compact with 16-bit UID/GID,
20 64-byte extended with 32-bit UID/GID,
22 and a modification time
25 .\" See fs/erofs/super.c:shmem_parse_options for options it supports.
33 extended attributes are exposed.
39 Controls whether POSIX
44 .BR cache_strategy = disabled | readahead | readaround
45 Cache allocation for compressed files:
46 never, if reading from start of file, regardless of position.
52 .BR dax = always | never
53 Direct Access control.
56 and the source device supports DAX, uncompressed non-inlined files
57 will be read directly, without going through the page cache.
61 Defaults to unset, which is equivalent to
64 .BR device = \fIblobdev\fP
65 Add extra device holding some of the data.
66 Must be given as many times and in the same order as
70 .\" Nominally there's a device_table feature and it somehow scans(?) for them,
71 .\" cf. super.c:erofs_scan_devices(), but I haven't gotten it to work
73 .BR domain_id = \fIdid\fP
76 Control CacheFiles on-demand read support.
80 images are versioned through the use of feature flags;
81 these are listed in the
86 Linux must be configured with the
88 option to mount EROFS filesystems.
89 There are sub-configuration items that restrict the availability
90 of some of the parameters above.
96 .I Documentation/filesystems/erofs.txt