The xattr name bloom filter feature is going to be introduced to speed
up the negative xattr lookup, e.g. system.posix_acl_[access|default]
lookup when running "ls -lR" workload.
There are some commonly used extended attributes (n) and the total
number of these is approximately 30.
trusted.overlay.opaque
trusted.overlay.redirect
trusted.overlay.origin
trusted.overlay.impure
trusted.overlay.nlink
trusted.overlay.upper
trusted.overlay.metacopy
trusted.overlay.protattr
user.overlay.opaque
user.overlay.redirect
user.overlay.origin
user.overlay.impure
user.overlay.nlink
user.overlay.upper
user.overlay.metacopy
user.overlay.protattr
security.evm
security.ima
security.selinux
security.SMACK64
security.SMACK64IPIN
security.SMACK64IPOUT
security.SMACK64EXEC
security.SMACK64TRANSMUTE
security.SMACK64MMAP
security.apparmor
security.capability
system.posix_acl_access
system.posix_acl_default
user.mime_type
Given the number of bits of the bloom filter (m) is 32, the optimal
value for the number of the hash functions (k) is 1 (ln2 * m/n = 0.74).
The single hash function is implemented as:
xxh32(name, strlen(name), EROFS_XATTR_FILTER_SEED + index)
where `index` represents the index of corresponding predefined short name
prefix, while `name` represents the name string after stripping the above
predefined name prefix.
The constant magic number EROFS_XATTR_FILTER_SEED, i.e. 0x25BBE08F, is
used to give a better spread when mapping these 30 extended attributes
into 32-bit bloom filter as:
bit 0: security.ima
bit 1:
bit 2: trusted.overlay.nlink
bit 3:
bit 4: user.overlay.nlink
bit 5: trusted.overlay.upper
bit 6: user.overlay.origin
bit 7: trusted.overlay.protattr
bit 8: security.apparmor
bit 9: user.overlay.protattr
bit 10: user.overlay.opaque
bit 11: security.selinux
bit 12: security.SMACK64TRANSMUTE
bit 13: security.SMACK64
bit 14: security.SMACK64MMAP
bit 15: user.overlay.impure
bit 16: security.SMACK64IPIN
bit 17: trusted.overlay.redirect
bit 18: trusted.overlay.origin
bit 19: security.SMACK64IPOUT
bit 20: trusted.overlay.opaque
bit 21: system.posix_acl_default
bit 22:
bit 23: user.mime_type
bit 24: trusted.overlay.impure
bit 25: security.SMACK64EXEC
bit 26: user.overlay.redirect
bit 27: user.overlay.upper
bit 28: security.evm
bit 29: security.capability
bit 30: system.posix_acl_access
bit 31: trusted.overlay.metacopy, user.overlay.metacopy
h_name_filter is introduced to the on-disk per-inode xattr header to
place the corresponding xattr name filter, where bit value 1 indicates
non-existence for compatibility.
This feature is indicated by EROFS_FEATURE_COMPAT_XATTR_FILTER
compatible feature bit.
Reserve one byte in on-disk superblock as the on-disk format for xattr
name filter may change in the future. With this flag we don't need
bothering these compatible bits again at that time.
Suggested-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230722094538.11754-2-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Add DEFLATE compression as the 3rd supported algorithm.
DEFLATE is a popular generic-purpose compression algorithm for quite
long time (many advanced formats like gzip, zlib, zip, png are all
based on that) as Apple documentation written "If you require
interoperability with non-Apple devices, use COMPRESSION_ZLIB. [1]".
Due to its popularity, there are several hardware on-market DEFLATE
accelerators, such as (s390) DFLTCC, (Intel) IAA/QAT, (HiSilicon) ZIP
accelerator, etc. In addition, there are also several high-performence
IP cores and even open-source FPGA approches available for DEFLATE.
Therefore, it's useful to support DEFLATE compression in order to find
a way to utilize these accelerators for asynchronous I/Os and get
benefits from these later.
Besides, it's a good choice to trade off between compression ratios
and performance compared to LZ4 and LZMA. The DEFLATE core format is
simple as well as easy to understand, therefore the code size of its
decompressor is small even for the bootloader use cases. The runtime
memory consumption is quite limited too (e.g. 32K + ~7K for each zlib
stream). As usual, EROFS ourperforms similar approaches too.
Alternatively, DEFLATE could still be used for some specific files
since EROFS supports multiple compression algorithms in one image.
[1] https://developer.apple.com/documentation/compression/compression_algorithm
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230810154859.118330-1-hsiangkao@linux.alibaba.com
Switch EROFS_I_{VERSION,DATALAYOUT}_BITS into
EROFS_I_{VERSION,DATALAYOUT}_MASK.
Also avoid erofs_bitrange() since its functionality is simple enough.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230414083027.12307-2-hsiangkao@linux.alibaba.com
Let's enable long xattr name prefix feature. Old kernels will just
ignore / skip such extended attributes. In addition, in case you
don't want to mount such images, add another incompatible feature as
an option for this.
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Acked-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230407222808.19670-1-jefflexu@linux.alibaba.com
[ Gao Xiang: minor commit message fix. ]
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Besides the predefined xattr name prefixes, introduces long xattr name
prefixes, which work similarly as the predefined name prefixes, except
that they are user specified.
It is especially useful for use cases together with overlayfs like
Composefs model, which introduces diverse xattr values with only a few
common xattr names (trusted.overlay.redirect, trusted.overlay.digest,
and maybe more in the future). That makes the existing predefined
prefixes ineffective in both image size and runtime performance.
When a user specified long xattr name prefix is used, only the trailing
part of the xattr name apart from the long xattr name prefix will be
stored in erofs_xattr_entry.e_name. e_name is empty if the xattr name
matches exactly as the long xattr name prefix. All long xattr prefixes
are stored in the packed or meta inode, which depends if fragments
feature is enabled or not.
For each long xattr name prefix, the on-disk format is kept as the same
as the unique metadata format: ALIGN({__le16 len, data}, 4), where len
represents the total size of struct erofs_xattr_long_prefix, followed
by data of struct erofs_xattr_long_prefix itself.
Each erofs_xattr_long_prefix keeps predefined prefixes (base_index)
and the remaining prefix string without the trailing '\0'.
Two fields are introduced to the on-disk superblock, where
xattr_prefix_count represents the total number of the long xattr name
prefixes recorded, and xattr_prefix_start represents the start offset of
recorded name prefixes in the packed/meta inode divided by 4.
When referring to a long xattr name prefix, the highest bit (bit 7) of
erofs_xattr_entry.e_name_index is set, while the lower bits (bit 0-6)
as a whole represents the index of the referred long name prefix among
all long xattr name prefixes.
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Acked-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230407141710.113882-5-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
- Get rid of all "vle" (variable-length extents) expressions
since they only expand overall name lengths unnecessarily;
- Rename COMPRESSION_LEGACY to COMPRESSED_FULL;
- Move on-disk directory definitions ahead of compression;
- Drop unused extended attribute definitions;
- Move inode ondisk union `i_u` out as `union erofs_inode_i_u`.
No actual logical change.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230331063149.25611-1-hsiangkao@linux.alibaba.com
Set the block size to that specified in on-disk superblock.
Also remove the hard constraint of PAGE_SIZE block size for the
uncompressed device backend. This constraint is temporarily remained
for compressed device and fscache backend, as there is more work needed
to handle the condition where the block size is not equal to PAGE_SIZE.
It is worth noting that the on-disk block size is read prior to
erofs_superblock_csum_verify(), as the read block size is needed in the
latter.
Besides, later we are going to make erofs refer to tar data blobs (which
is 512-byte aligned) for OCI containers, where the block size is 512
bytes. In this case, the 512-byte block size may not be adequate for a
directory to contain enough dirents. To fix this, we are also going to
introduce directory block size independent on the block size.
Due to we have already supported block size smaller than PAGE_SIZE now,
disable all these images with such separated directory block size until
we supported this feature later.
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230313135309.75269-3-jefflexu@linux.alibaba.com
[ Gao Xiang: update documentation. ]
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Due to deduplication for compressed data, pclusters can be partially
referenced with their prefixes.
Together with the user-space implementation, it enables EROFS
variable-length global compressed data deduplication with rolling
hash.
Link: https://lore.kernel.org/r/20220923014915.4362-1-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Introduce on-disk compressed fragments data feature.
This approach adds a new field called `h_fragmentoff' in the per-file
compression header to indicate the fragment offset of each tail pcluster
or the whole file in the special packed inode.
Similar to ztailpacking, it will also find and record the 'headlcn'
of the tail pcluster when initializing per-inode zmap for making
follow-on requests more easy.
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/YzHKxcFTlHGgXeH9@B-P7TQMD6M-0146.local
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Currently, uncompressed data is all handled in the shifted way, which
means we have to shift the whole on-disk plain pcluster to get the
logical data. However, since we are also using in-place I/O for
uncompressed data, data copy will be reduced a lot if pcluster is
recorded in the interlaced way as illustrated below:
_______________________________________________________________
| | | |_ tail part |_ head part _|
|<- blk0 ->| .. |<- blkn-2 ->|<- blkn-1 ->|
The logical data then becomes:
________________________________________________________
|_ head part _|_ blk0 _| .. |_ blkn-2 _|_ tail part _|
In addition, non-4k plain pclusters are also survived by the
interlaced way, which can be used for non-4k lclusters as well.
However, it's almost impossible to de-duplicate uncompressed data
in the interlaced way, therefore shifted uncompressed data is still
useful.
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/8369112678604fdf4ef796626d59b1fdd0745a53.1663898962.git.huyue2@coolpad.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
When "-o device" mount option is not specified, scan the device table
and instantiate the devices if there's any in the device table. In this
case, the tag field of each device slot uniquely specifies a device.
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220512055601.106109-1-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
EROFS images should inherit modification time rather than change time,
since users and host tooling have no easy way to control change time.
To reflect the new timestamp meaning, i_ctime and i_ctime_nsec are
renamed to i_mtime and i_mtime_nsec.
Link: https://lore.kernel.org/r/20220311041829.3109511-1-dvander@google.com # v1
Signed-off-by: David Anderson <dvander@google.com>
[ Gao Xiang: update document as well. ]
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20220317114959.106787-1-hsiangkao@linux.alibaba.com # v2
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Introduces erofs compressed tail-packing inline support.
This approach adds a new field called `h_idata_size' in the
per-file compression header to indicate the encoded size of
each tail-packing pcluster.
At runtime, it will find the start logical offset of the tail
pcluster when initializing per-inode zmap and record such
extent (headlcn, idataoff) information to the in-memory inode.
Therefore, follow-on requests can directly recognize if one
pcluster is a tail-packing inline pcluster or not.
Link: https://lore.kernel.org/r/20211228054604.114518-6-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Renaming lz4_0padding to zero_padding globally since LZMA and later
algorithms also need that.
Link: https://lore.kernel.org/r/20211112160935.19394-1-jnhuang95@gmail.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Add MicroLZMA support in order to maximize compression ratios for
specific scenarios. For example, it's useful for low-end embedded
boards and as a secondary algorithm in a file for specific access
patterns.
MicroLZMA is a new container format for raw LZMA1, which was created
by Lasse Collin aiming to minimize old LZMA headers and get rid of
unnecessary EOPM (end of payload marker) as well as to enable
fixed-sized output compression, especially for 4KiB pclusters.
Similar to LZ4, inplace I/O approach is used to minimize runtime
memory footprint when dealing with I/O. Overlapped decompression is
handled with 1) bounced buffer for data under processing or 2) extra
short-lived pages from the on-stack pagepool which will be shared in
the same read request (128KiB for example).
Link: https://lore.kernel.org/r/20211010213145.17462-8-xiang@kernel.org
Acked-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Previously, for each HEAD lcluster, it can be either HEAD or PLAIN
lcluster to indicate whether the whole pcluster is compressed or not.
In this patch, a new HEAD2 head type is introduced to specify another
compression algorithm other than the primary algorithm for each
compressed file, which can be used for upcoming LZMA compression and
LZ4 range dictionary compression for various data patterns.
It has been stayed in the EROFS roadmap for years. Complete it now!
Link: https://lore.kernel.org/r/20211017165721.2442-1-xiang@kernel.org
Reviewed-by: Yue Hu <huyue2@yulong.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
In order to support multi-layer container images, add multiple
device feature to EROFS. Two ways are available to use for now:
- Devices can be mapped into 32-bit global block address space;
- Device ID can be specified with the chunk indexes format.
Note that it assumes no extent would cross device boundary and mkfs
should take care of it seriously.
In the future, a dedicated device manager could be introduced then
thus extra devices can be automatically scanned by UUID as well.
Link: https://lore.kernel.org/r/20211014081010.43485-1-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Currently, uncompressed data except for tail-packing inline is
consecutive on disk.
In order to support chunk-based data deduplication, add a new
corresponding inode data layout.
In the future, the data source of chunks can be either (un)compressed.
Link: https://lore.kernel.org/r/20210820100019.208490-1-hsiangkao@linux.alibaba.com
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Big pcluster indicates the size of compressed data for each physical
pcluster is no longer fixed as block size, but could be more than 1
block (more accurately, 1 logical pcluster)
When big pcluster feature is enabled for head0/1, delta0 of the 1st
non-head lcluster index will keep block count of this pcluster in
lcluster size instead of 1. Or, the compressed size of pcluster
should be 1 lcluster if pcluster has no non-head lcluster index.
Also note that BIG_PCLUSTER feature reuses COMPR_CFGS feature since
it depends on COMPR_CFGS and will be released together.
Link: https://lore.kernel.org/r/20210407043927.10623-6-xiang@kernel.org
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Since multiple pcluster sizes could be used at once, the number of
compressed pages will become a variable factor. It's necessary to
introduce slab pools rather than a single slab cache now.
This limits the pclustersize to 1M (Z_EROFS_PCLUSTER_MAX_SIZE), and
get rid of the obsolete EROFS_FS_CLUSTER_PAGE_LIMIT, which has no
use now.
Link: https://lore.kernel.org/r/20210407043927.10623-4-xiang@kernel.org
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Formal big pcluster design is actually more powerful / flexable than
the previous thought whose pclustersize was fixed as power-of-2 blocks,
which was obviously inefficient and space-wasting. Instead, pclustersize
can now be set independently for each pcluster, so various pcluster
sizes can also be used together in one file if mkfs wants (for example,
according to data type and/or compression ratio).
Let's get rid of previous physical_clusterbits[] setting (also notice
that corresponding on-disk fields are still 0 for now). Therefore,
head1/2 can be used for at most 2 different algorithms in one file and
again pclustersize is now independent of these.
Link: https://lore.kernel.org/r/20210407043927.10623-2-xiang@kernel.org
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Add a bitmap for available compression algorithms and a variable-sized
on-disk table for compression options in preparation for upcoming big
pcluster and LZMA algorithm, which follows the end of super block.
To parse the compression options, the bitmap is scanned one by one.
For each available algorithm, there is data followed by 2-byte `length'
correspondingly (it's enough for most cases, or entire fs blocks should
be used.)
With such available algorithm bitmap, kernel itself can also refuse to
mount such filesystem if any unsupported compression algorithm exists.
Note that COMPR_CFGS feature will be enabled with BIG_PCLUSTER.
Link: https://lore.kernel.org/r/20210329100012.12980-1-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Introduce z_erofs_lz4_cfgs to store all lz4 configurations.
Currently it's only max_distance, but will be used for new
features later.
Link: https://lore.kernel.org/r/20210329012308.28743-4-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
lz4 uses LZ4_DISTANCE_MAX to record history preservation. When
using rolling decompression, a block with a higher compression
ratio will cause a larger memory allocation (up to 64k). It may
cause a large resource burden in extreme cases on devices with
small memory and a large number of concurrent IOs. So appropriately
reducing this value can improve performance.
Decreasing this value will reduce the compression ratio (except
when input_size <LZ4_DISTANCE_MAX). But considering that erofs
currently only supports 4k output, reducing this value will not
significantly reduce the compression benefits.
The maximum value of LZ4_DISTANCE_MAX defined by lz4 is 64k, and
we can only reduce this value. For the old kernel, it just can't
reduce the memory allocation during rolling decompression without
affecting the decompression result.
Link: https://lore.kernel.org/r/20210329012308.28743-3-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
[ Gao Xiang: introduce struct erofs_sb_lz4_info for configurations. ]
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
If any unknown i_format fields are set (may be of some new incompat
inode features), mark such inode as unsupported.
Just in case of any new incompat i_format fields added in the future.
Link: https://lore.kernel.org/r/20210329003614.6583-1-hsiangkao@aol.com
Fixes: 431339ba90 ("staging: erofs: add inode operations")
Cc: <stable@vger.kernel.org> # 4.19+
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200713130944.34419-1-grandmaster@al2klimov.de
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Introduce superblock checksum feature in order to
check at mounting time.
Note that the first 1024 bytes are ignore for x86
boot sectors and other oddities.
Link: https://lore.kernel.org/r/20191104024937.113939-1-gaoxiang25@huawei.com
Signed-off-by: Pratik Shinde <pratikshinde320@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
As Christoph said, "This looks like a really obsfucated
way to write:
return datamode == EROFS_INODE_FLAT_COMPRESSION ||
datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY; "
Although I had my own consideration, it's the right way for now.
[1] https://lore.kernel.org/r/20190829095954.GB20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-6-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As Christoph suggested "Please don't add __packed" [1],
remove all __packed except struct erofs_dirent here.
Note that all on-disk fields except struct erofs_dirent
(12 bytes with a 8-byte nid) in EROFS are naturally aligned.
[1] https://lore.kernel.org/r/20190829095954.GB20598@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-5-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
EROFS filesystem has been merged into linux-staging for a year.
EROFS is designed to be a better solution of saving extra storage
space with guaranteed end-to-end performance for read-only files
with the help of reduced metadata, fixed-sized output compression
and decompression inplace technologies.
In the past year, EROFS was greatly improved by many people as
a staging driver, self-tested, betaed by a large number of our
internal users, successfully applied to almost all in-service
HUAWEI smartphones as the part of EMUI 9.1 and proven to be stable
enough to be moved out of staging.
EROFS is a self-contained filesystem driver. Although there are
still some TODOs to be more generic, we have a dedicated team
actively keeping on working on EROFS in order to make it better
with the evolution of Linux kernel as the other in-kernel filesystems.
As Pavel suggested, it's better to do as one commit since git
can do moves and all histories will be saved in this way.
Let's promote it from staging and enhance it more actively as
a "real" part of kernel for more wider scenarios!
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Pavel Machek <pavel@denx.de>
Cc: David Sterba <dsterba@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J . Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Fang Wei <fangwei1@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190822213659.5501-1-hsiangkao@aol.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
