[PATCH] erofs: update the Kconfig description

[PATCH] erofs: update the Kconfig description

[Gao Xiang]

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.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
 fs/erofs/Kconfig | 45 ++++++++++++++++++++++++++++++---------------
 1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index a9f645f57bb2..9489ed8ad95b 100644
--- 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
+	  for filesytem 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.
 
-- 
2.43.5

Re: [PATCH] erofs: update the Kconfig description

[Chao Yu]

On 3/23/26 17:48, Gao Xiang wrote:
> 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.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
>  fs/erofs/Kconfig | 45 ++++++++++++++++++++++++++++++---------------
>  1 file changed, 30 insertions(+), 15 deletions(-)
> 
> diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
> index a9f645f57bb2..9489ed8ad95b 100644
> --- 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
> +	  for filesytem auditing and remote access; inline data, random-access

duplicated 'for'? otherwise, looks good to me.

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

> +	  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.
>  

Re: [PATCH] erofs: update the Kconfig description

[Gao Xiang]

Hi Chao,

On 2026/3/23 17:59, Chao Yu wrote:
> On 3/23/26 17:48, Gao Xiang wrote:
>> 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.
>>
>> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
>> ---
>>   fs/erofs/Kconfig | 45 ++++++++++++++++++++++++++++++---------------
>>   1 file changed, 30 insertions(+), 15 deletions(-)
>>
>> diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
>> index a9f645f57bb2..9489ed8ad95b 100644
>> --- 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
>> +	  for filesytem auditing and remote access; inline data, random-access
> 
> duplicated 'for'? otherwise, looks good to me.

Fixed and thanks for the review!

> 
> Reviewed-by: Chao Yu <chao@kernel.org>
> 
> Thanks,

Thanks,
Gao Xiang