erofs: support idmapped mounts

This patch enables idmapped mounts for erofs, since all dedicated helpers
for this functionality existsm, so, in this patch we just pass down the
user_namespace argume

erofs: support idmapped mounts

This patch enables idmapped mounts for erofs, since all dedicated helpers
for this functionality existsm, so, in this patch we just pass down the
user_namespace argument from the VFS methods to the relevant helpers.

Simple idmap example on erofs image:

1. mkdir dir
2. touch dir/file
3. mkfs.erofs erofs.img dir
4. mount -t erofs -o loop erofs.img /mnt/erofs/

5. ls -ln /mnt/erofs/
total 0
-rw-rw-r-- 1 1000 1000 0 May 17 15:26 file

6. mount-idmapped --map-mount b:1000:1001:1 /mnt/erofs/ /mnt/scratch_erofs/

7. ls -ln /mnt/scratch_erofs/
total 0
-rw-rw-r-- 1 1001 1001 0 May 17 15:26 file

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Link: https://lore.kernel.org/r/20220517104103.3570721-1-chao@kernel.org
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

erofs: make filesystem exportable

Implement export operations in order to make EROFS support accessing
inodes with filehandles so that it can be exported via NFS and used
by overlayfs.

Without this

erofs: make filesystem exportable

Implement export operations in order to make EROFS support accessing
inodes with filehandles so that it can be exported via NFS and used
by overlayfs.

Without this patch, 'exportfs -rv' will report:
exportfs: /root/erofs_mp does not support NFS export

Also tested with unionmount-testsuite and the testcase below passes now:
./run --ov --erofs --verify hard-link

For more details about the testcase, see:
https://github.com/amir73il/unionmount-testsuite/pull/6

Signed-off-by: Hongnan Li <hongnan.li@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20220425040712.91685-1-hongnan.li@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

erofs: Convert to release_folio

Use a folio in erofs_managed_cache_release_folio(), but use of folios
should be pushed into erofs_try_to_free_cached_page().

Signed-off-by: Matthew Wilcox (Oracle) <

erofs: Convert to release_folio

Use a folio in erofs_managed_cache_release_folio(), but use of folios
should be pushed into erofs_try_to_free_cached_page().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

show more ...

fs: allocate inode by using alloc_inode_sb()

The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().

Link: https://lkml.kerne

fs: allocate inode by using alloc_inode_sb()

The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().

Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> [ext4]
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

erofs: refine managed inode stuffs

Set up the correct gfp mask and use it instead of hard coding.
Also add comments about .invalidatepage() to show more details.

Link: https://lore.kernel.org/r/202

erofs: refine managed inode stuffs

Set up the correct gfp mask and use it instead of hard coding.
Also add comments about .invalidatepage() to show more details.

Link: https://lore.kernel.org/r/20220310182743.102365-2-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

erofs: use meta buffers for erofs_read_superblock()

The only change is that, meta buffers read cache page without __GFP_FS
flag, which shall not matter.

Link: https://lore.kernel.org/r/202202090601

erofs: use meta buffers for erofs_read_superblock()

The only change is that, meta buffers read cache page without __GFP_FS
flag, which shall not matter.

Link: https://lore.kernel.org/r/20220209060108.43051-7-jefflexu@linux.alibaba.com
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

erofs: Convert from invalidatepage to invalidate_folio

A straightforward conversion.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource

erofs: Convert from invalidatepage to invalidate_folio

A straightforward conversion.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs

show more ...

erofs: use meta buffers for super operations

Get rid of old erofs_get_meta_page() within super operations by
using on-stack meta buffers in order to prepare subpage and folio
features.

Link: https:

erofs: use meta buffers for super operations

Get rid of old erofs_get_meta_page() within super operations by
using on-stack meta buffers in order to prepare subpage and folio
features.

Link: https://lore.kernel.org/r/20220102081317.109797-1-hsiangkao@linux.alibaba.com
Reviewed-by: Yue Hu <huyue2@yulong.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>

show more ...

erofs: add on-disk compressed tail-packing inline support

Introduces erofs compressed tail-packing inline support.

This approach adds a new field called `h_idata_size' in the
per-file compression h

erofs: add on-disk compressed tail-packing inline support

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>

show more ...

erofs: add sysfs node to control sync decompression strategy

Although readpage is a synchronous path, there will be no additional
kworker scheduling overhead in non-atomic contexts together with
dm-

erofs: add sysfs node to control sync decompression strategy

Although readpage is a synchronous path, there will be no additional
kworker scheduling overhead in non-atomic contexts together with
dm-verity.

Let's add a sysfs node to disable sync decompression as an option.

Link: https://lore.kernel.org/r/20211206143552.8384-1-huangjianan@oppo.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>

show more ...

erofs: add sysfs interface

Add sysfs interface to configure erofs related parameters later.

Link: https://lore.kernel.org/r/20211201145436.4357-1-huangjianan@oppo.com
Reviewed-by: Chao Yu <chao@ker

erofs: add sysfs interface

Add sysfs interface to configure erofs related parameters later.

Link: https://lore.kernel.org/r/20211201145436.4357-1-huangjianan@oppo.com
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

dax: return the partition offset from fs_dax_get_by_bdev

Prepare for the removal of the block_device from the DAX I/O path by
returning the partition offset from fs_dax_get_by_bdev so that the file

dax: return the partition offset from fs_dax_get_by_bdev

Prepare for the removal of the block_device from the DAX I/O path by
returning the partition offset from fs_dax_get_by_bdev so that the file
systems have it at hand for use during I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-26-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

show more ...

dax: remove dax_capable

Just open code the block size and dax_dev == NULL checks in the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-b

dax: remove dax_capable

Just open code the block size and dax_dev == NULL checks in the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> [erofs]
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-9-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

show more ...

erofs: lzma compression support

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 algorith

erofs: lzma compression support

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>

show more ...

erofs: add multiple device support

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-bi

erofs: add multiple device support

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>

show more ...

erofs: decouple basic mount options from fs_context

Previously, EROFS mount options are all in the basic types, so
erofs_fs_context can be directly copied with assignment. However,
when the multiple

erofs: decouple basic mount options from fs_context

Previously, EROFS mount options are all in the basic types, so
erofs_fs_context can be directly copied with assignment. However,
when the multiple device feature is introduced, it's hard to handle
multiple device information like the other basic mount options.

Let's separate basic mount option usage from fs_context, thus
multiple device information can be handled gracefully then.

No logic changes.

Link: https://lore.kernel.org/r/20211007070224.12833-1-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>

show more ...

erofs: remove the mapping parameter from erofs_try_to_free_cached_page()

The mapping is not used at all, remove it and update related code.

Link: https://lore.kernel.org/r/20210810072416.1392-1-zbe

erofs: remove the mapping parameter from erofs_try_to_free_cached_page()

The mapping is not used at all, remove it and update related code.

Link: https://lore.kernel.org/r/20210810072416.1392-1-zbestahu@gmail.com
Reviewed-by: Gao Xiang <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>

show more ...

erofs: dax support for non-tailpacking regular file

DAX is quite useful for some VM use cases in order to save guest
memory extremely with minimal lightweight EROFS.

In order to prepare for such us

erofs: dax support for non-tailpacking regular file

DAX is quite useful for some VM use cases in order to save guest
memory extremely with minimal lightweight EROFS.

In order to prepare for such use cases, add preliminary dax support
for non-tailpacking regular files for now.

Tested with the DRAM-emulated PMEM and the EROFS image generated by
"mkfs.erofs -Enoinline_data enwik9.fsdax.img enwik9"

Link: https://lore.kernel.org/r/20210805003601.183063-3-hsiangkao@linux.alibaba.com
Cc: nvdimm@lists.linux.dev
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

erofs: clean up file headers & footers

- Remove my outdated misleading email address;

- Get rid of all unnecessary trailing newline by accident.

Link: https://lore.kernel.org/r/20210602160634.10

erofs: clean up file headers & footers

- Remove my outdated misleading email address;

- Get rid of all unnecessary trailing newline by accident.

Link: https://lore.kernel.org/r/20210602160634.10757-1-xiang@kernel.org
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

show more ...

erofs: fix error return code in erofs_read_superblock()

'ret' will be overwritten to 0 if erofs_sb_has_sb_chksum() return true,
thus 0 will return in some error handling cases. Fix to return negativ

erofs: fix error return code in erofs_read_superblock()

'ret' will be overwritten to 0 if erofs_sb_has_sb_chksum() return true,
thus 0 will return in some error handling cases. Fix to return negative
error code -EINVAL instead of 0.

Link: https://lore.kernel.org/r/20210519141657.3062715-1-weiyongjun1@huawei.com
Fixes: b858a4844cfb ("erofs: support superblock checksum")
Cc: stable <stable@vger.kernel.org> # 5.5+
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Gao Xiang <xiang@kernel.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <xiang@kernel.org>

show more ...

erofs: introduce multipage per-CPU buffers

To deal the with the cases which inplace decompression is infeasible
for some inplace I/O. Per-CPU buffers was introduced to get rid of page
allocation lat

erofs: introduce multipage per-CPU buffers

To deal the with the cases which inplace decompression is infeasible
for some inplace I/O. Per-CPU buffers was introduced to get rid of page
allocation latency and thrash for low-latency decompression algorithms
such as lz4.

For the big pcluster feature, introduce multipage per-CPU buffers to
keep such inplace I/O pclusters temporarily as well but note that
per-CPU pages are just consecutive virtually.

When a new big pcluster fs is mounted, its max pclustersize will be
read and per-CPU buffers can be growed if needed. Shrinking adjustable
per-CPU buffers is more complex (because we don't know if such size
is still be used), so currently just release them all when unloading.

Link: https://lore.kernel.org/r/20210409190630.19569-1-xiang@kernel.org
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

show more ...

erofs: add on-disk compression configurations

Add a bitmap for available compression algorithms and a variable-sized
on-disk table for compression options in preparation for upcoming big
pcluster an

erofs: add on-disk compression configurations

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>

show more ...

erofs: introduce on-disk lz4 fs configurations

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://l

erofs: introduce on-disk lz4 fs configurations

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>

show more ...

erofs: support adjust lz4 history window size

lz4 uses LZ4_DISTANCE_MAX to record history preservation. When
using rolling decompression, a block with a higher compression
ratio will cause a larger

erofs: support adjust lz4 history window size

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>

show more ...

erofs: introduce erofs_sb_has_xxx() helpers

Introduce erofs_sb_has_xxx() to make long checks short, especially
for later big pcluster & LZMA features.

Link: https://lore.kernel.org/r/20210329012308

erofs: introduce erofs_sb_has_xxx() helpers

Introduce erofs_sb_has_xxx() to make long checks short, especially
for later big pcluster & LZMA features.

Link: https://lore.kernel.org/r/20210329012308.28743-2-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

show more ...