erofs: update the Kconfig description

Refine the description to better highlight its features and use cases.

In addition, add instructions for building it as a module and clarify
the compression option.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index a9f645f57bb23f8951e6c35466f1fa0e284ac91a..97c48ebe84584f5113c8aa7bee9aa8268384e02e 100644 (file)
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -16,22 +16,36 @@ config EROFS_FS
        select ZLIB_INFLATE if EROFS_FS_ZIP_DEFLATE
        select ZSTD_DECOMPRESS if EROFS_FS_ZIP_ZSTD
        help
-         EROFS (Enhanced Read-Only File System) is a lightweight read-only
-         file system with modern designs (e.g. no buffer heads, inline
-         xattrs/data, chunk-based deduplication, multiple devices, etc.) for
-         scenarios which need high-performance read-only solutions, e.g.
-         smartphones with Android OS, LiveCDs and high-density hosts with
-         numerous containers;
-
-         It also provides transparent compression and deduplication support to
-         improve storage density and maintain relatively high compression
-         ratios, and it implements in-place decompression to temporarily reuse
-         page cache for compressed data using proper strategies, which is
-         quite useful for ensuring guaranteed end-to-end runtime decompression
+         EROFS (Enhanced Read-Only File System) is a modern, lightweight,
+         secure read-only filesystem for various use cases, such as immutable
+         system images, container images, application sandboxes, and datasets.
+
+         EROFS uses a flexible, hierarchical on-disk design so that features
+         can be enabled on demand: the core on-disk format is block-aligned in
+         order to perform optimally on all kinds of devices, including block
+         and memory-backed devices; the format is easy to parse and has zero
+         metadata redundancy, unlike generic filesystems, making it ideal for
+         filesystem auditing and remote access; inline data, random-access
+         friendly directory data, inline/shared extended attributes and
+         chunk-based deduplication ensure space efficiency while maintaining
+         high performance.
+
+         Optionally, it supports multiple devices to reference external data,
+         enabling data sharing for container images.
+
+         It also has advanced encoded on-disk layouts, particularly for data
+         compression and fine-grained deduplication. It utilizes fixed-size
+         output compression to improve storage density while keeping relatively
+         high compression ratios. Furthermore, it implements in-place
+         decompression to reuse file pages to keep compressed data temporarily
+         with proper strategies, which ensures guaranteed end-to-end runtime
          performance under extreme memory pressure without extra cost.
 
-         See the documentation at <file:Documentation/filesystems/erofs.rst>
-         and the web pages at <https://erofs.docs.kernel.org> for more details.
+         For more details, see the web pages at <https://erofs.docs.kernel.org>
+         and the documentation at <file:Documentation/filesystems/erofs.rst>.
+
+         To compile EROFS filesystem support as a module, choose M here. The
+         module will be called erofs.
 
          If unsure, say N.
 
@@ -105,7 +119,8 @@ config EROFS_FS_ZIP
        depends on EROFS_FS
        default y
        help
-         Enable transparent compression support for EROFS file systems.
+         Enable EROFS compression layouts so that filesystems containing
+         compressed files can be parsed by the kernel.
 
          If you don't want to enable compression feature, say N.