erofs: get rid of magical Z_EROFS_MAPPING_STAGING

Previously, we played around with magical page->mapping for short-lived
temporary pages since we need to identify different types of pages in
the sa

erofs: get rid of magical Z_EROFS_MAPPING_STAGING

Previously, we played around with magical page->mapping for short-lived
temporary pages since we need to identify different types of pages in
the same pcluster but both invalidated and short-lived temporary pages
can have page->mapping == NULL. It was considered as safe because that
temporary pages are all non-LRU / non-movable pages.

This patch tends to use specific page->private to identify short-lived
pages instead so it won't rely on page->mapping anymore. Details are
described in "compress.h" as well.

Link: https://lore.kernel.org/r/20201208095834.3133565-1-hsiangkao@redhat.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: fix setting up pcluster for temporary pages

pcluster should be only set up for all managed pages instead of
temporary pages. Since it currently uses page->mapping to identify,
the impact is m

erofs: fix setting up pcluster for temporary pages

pcluster should be only set up for all managed pages instead of
temporary pages. Since it currently uses page->mapping to identify,
the impact is minor for now.

[ Update: Vladimir reported the kernel log becomes polluted
because PAGE_FLAGS_CHECK_AT_FREE flag(s) set if the page
allocation debug option is enabled. ]

Link: https://lore.kernel.org/r/20201022145724.27284-1-hsiangkao@aol.com
Fixes: 5ddcee1f3a1c ("erofs: get rid of __stagingpage_alloc helper")
Cc: <stable@vger.kernel.org> # 5.5+
Tested-by: Vladimir Zapolskiy <vladimir@tuxera.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: add REQ_RAHEAD flag to readahead requests

Let's add REQ_RAHEAD flag so it'd be easier to identify
readahead I/O requests in blktrace.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://

erofs: add REQ_RAHEAD flag to readahead requests

Let's add REQ_RAHEAD flag so it'd be easier to identify
readahead I/O requests in blktrace.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200919072730.24989-3-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: fold in should_decompress_synchronously()

should_decompress_synchronously() has one single condition
for now, so fold it instead.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore

erofs: fold in should_decompress_synchronously()

should_decompress_synchronously() has one single condition
for now, so fold it instead.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200919072730.24989-2-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: avoid unnecessary variable `err'

variable `err' in z_erofs_submit_queue() isn't useful
here, remove it instead.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/2020

erofs: avoid unnecessary variable `err'

variable `err' in z_erofs_submit_queue() isn't useful
here, remove it instead.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200919072730.24989-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: remove unneeded parameter

After commit 0615090c5044 ("erofs: convert compressed files from
readpages to readahead"), add_to_page_cache_lru() was moved to mm
code, so that in below call path,

erofs: remove unneeded parameter

After commit 0615090c5044 ("erofs: convert compressed files from
readpages to readahead"), add_to_page_cache_lru() was moved to mm
code, so that in below call path, no page will be cached into
@pagepool list or grabbed from @pagepool list:
- z_erofs_readpage
- z_erofs_do_read_page
- preload_compressed_pages
- erofs_allocpage

Let's get rid of this unneeded @pagepool parameter.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200917011821.22767-1-yuchao0@huawei.com
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: remove WQ_CPU_INTENSIVE flag from unbound wq's

The documentation [1] says that WQ_CPU_INTENSIVE is "meaningless" for
unbound wq. I remove this flag from places where unbound queue is
allocate

erofs: remove WQ_CPU_INTENSIVE flag from unbound wq's

The documentation [1] says that WQ_CPU_INTENSIVE is "meaningless" for
unbound wq. I remove this flag from places where unbound queue is
allocated. This is supposed to improve code readability.

[1] https://www.kernel.org/doc/html/latest/core-api/workqueue.html#flags
Signed-off-by: Maksym Planeta <mplaneta@os.inf.tu-dresden.de>
[Gao Xiang: since the original treewide patch [2] hasn't been merged
yet, handling the EROFS part only for the next cycle. ]
[2] https://lore.kernel.org/r/20200213141823.2174236-1-mplaneta@os.inf.tu-dresden.de
Link: https://lore.kernel.org/r/20200731024049.16495-1-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For eac

erofs: Replace HTTP links with HTTPS ones

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>

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treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused vari

treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

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erofs: convert compressed files from readpages to readahead

Use the new readahead operation in erofs.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm

erofs: convert compressed files from readpages to readahead

Use the new readahead operation in erofs.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Gao Xiang <gaoxiang25@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-20-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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erofs: convert uncompressed files from readpages to readahead

Use the new readahead operation in erofs

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akp

erofs: convert uncompressed files from readpages to readahead

Use the new readahead operation in erofs

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Gao Xiang <gaoxiang25@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-19-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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erofs: convert to use the new mount fs_context api

Convert the erofs to use new internal mount API as the old one will
be obsoleted and removed. This allows greater flexibility in
communication of

erofs: convert to use the new mount fs_context api

Convert the erofs to use new internal mount API as the old one will
be obsoleted and removed. This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200529104836.17843-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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erofs: convert workstn to XArray

XArray has friendly APIs and it will replace the old radix
tree in the near future.

This convert makes use of __xa_cmpxchg when inserting on
a just inserted item by

erofs: convert workstn to XArray

XArray has friendly APIs and it will replace the old radix
tree in the near future.

This convert makes use of __xa_cmpxchg when inserting on
a just inserted item by other thread. In detail, instead
of totally looking up again as what we did for the old
radix tree, it will try to legitimize the current in-tree
item in the XArray therefore more effective.

In addition, naming is rather a challenge for non-English
speaker like me. The basic idea of workstn is to provide
a runtime sparse array with items arranged in the physical
block number order. Such items (was called workgroup) can be
used to record compress clusters or for later new features.

However, both workgroup and workstn seem not good names from
whatever point of view, so I'd like to rename them as pslot
and managed_pslots to stand for physical slots. This patch
handles the second as a part of the radix tree convert.

Cc: Matthew Wilcox <willy@infradead.org>
Link: https://lore.kernel.org/r/20200220024642.91529-1-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: clean up z_erofs_submit_queue()

A label and extra variables will be eliminated,
which is more cleaner.

Link: https://lore.kernel.org/r/20200121064819.139469-1-gaoxiang25@huawei.com
Reviewed-

erofs: clean up z_erofs_submit_queue()

A label and extra variables will be eliminated,
which is more cleaner.

Link: https://lore.kernel.org/r/20200121064819.139469-1-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: fold in postsubmit_is_all_bypassed()

No need to introduce such separated helper since
cache strategy compile configs were changed into
runtime options instead in v5.4. No logic changes.

Link

erofs: fold in postsubmit_is_all_bypassed()

No need to introduce such separated helper since
cache strategy compile configs were changed into
runtime options instead in v5.4. No logic changes.

Link: https://lore.kernel.org/r/20200121064747.138987-1-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: remove unused tag argument while registering a workgroup

All workgroups are registered with tag value set to 0, to simplify
erofs_register_workgroup() interface the tag argument can be remove

erofs: remove unused tag argument while registering a workgroup

All workgroups are registered with tag value set to 0, to simplify
erofs_register_workgroup() interface the tag argument can be removed,
if its only value is sent down to the function body.

Signed-off-by: Vladimir Zapolskiy <vladimir@tuxera.com>
Link: https://lore.kernel.org/r/20200102120118.14979-3-vladimir@tuxera.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: remove unused tag argument while finding a workgroup

It is feasible to simplify erofs_find_workgroup() interface by removing
an unused function argument. While formally the argument is used i

erofs: remove unused tag argument while finding a workgroup

It is feasible to simplify erofs_find_workgroup() interface by removing
an unused function argument. While formally the argument is used in the
function itself, its assigned value is ignored on the caller side.

Signed-off-by: Vladimir Zapolskiy <vladimir@tuxera.com>
Link: https://lore.kernel.org/r/20200102120118.14979-2-vladimir@tuxera.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: drop all vle annotations for runtime names

VLE was an old informal name of fixed-sized output
compression which came from published ATC'19 paper [1].

Drop those old annotations since erofs c

erofs: drop all vle annotations for runtime names

VLE was an old informal name of fixed-sized output
compression which came from published ATC'19 paper [1].

Drop those old annotations since erofs can handle
all encoded clusters in block-aligned basis, which
is wider than fixed-sized output compression after
larger clustersize feature is fully implemented.

Unaligned encoding won't be considered in EROFS
since it's not friendly to inplace I/O and perhaps
decompression inplace.

a) Fixed-sized output compression with 16KB pcluster:
___________________________________
|xxxxxxxx|xxxxxxxx|xxxxxxxx|xxxxxxxx|
|___ 0___|___ 1___|___ 2___|___ 3___| physical blocks

b) Block-aligned fixed-sized input compression with
16KB pcluster:
___________________________________
|xxxxxxxx|xxxxxxxx|xxxxxxxx|xxx00000|
|___ 0___|___ 1___|___ 2___|___ 3___| physical blocks

c) Block-unaligned fixed-sized input compression with
16KB compression unit:
____________________________________________
|..xxxxxx|xxxxxxxx|xxxxxxxx|xxxxxxxx|x.......|
|___ 0___|___ 1___|___ 2___|___ 3___|___ 4___| physical blocks

Refine better names for those as well.

[1] https://www.usenix.org/conference/atc19/presentation/gao

Link: https://lore.kernel.org/r/20191108033733.63919-1-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: set iowait for sync decompression

For those tasks waiting I/O for sync decompression,
they should be better marked as IO wait state.

Link: https://lore.kernel.org/r/20191008125616.183715-5-g

erofs: set iowait for sync decompression

For those tasks waiting I/O for sync decompression,
they should be better marked as IO wait state.

Link: https://lore.kernel.org/r/20191008125616.183715-5-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: clean up decompress queue stuffs

Previously, both z_erofs_unzip_io and z_erofs_unzip_io_sb
record decompress queues for backend to use.

The only difference is that z_erofs_unzip_io is used f

erofs: clean up decompress queue stuffs

Previously, both z_erofs_unzip_io and z_erofs_unzip_io_sb
record decompress queues for backend to use.

The only difference is that z_erofs_unzip_io is used for
on-stack sync decompression so that it doesn't have a super
block field (since the caller can pass it in its context),
but it increases complexity with only a pointer saving.

Rename z_erofs_unzip_io to z_erofs_decompressqueue with
a fixed super_block member and kill the other entirely,
and it can fallback to sync decompression if memory
allocation failure.

Link: https://lore.kernel.org/r/20191008125616.183715-4-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: get rid of __stagingpage_alloc helper

Now open code is much cleaner due to iterative development.

Link: https://lore.kernel.org/r/20191124025217.12345-1-hsiangkao@aol.com
Reviewed-by: Chao Y

erofs: get rid of __stagingpage_alloc helper

Now open code is much cleaner due to iterative development.

Link: https://lore.kernel.org/r/20191124025217.12345-1-hsiangkao@aol.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: remove dead code since managed cache is now built-in

After commit 4279f3f9889f ("staging: erofs: turn cache
strategies into mount options"), cache strategies are
changed into mount options ra

erofs: remove dead code since managed cache is now built-in

After commit 4279f3f9889f ("staging: erofs: turn cache
strategies into mount options"), cache strategies are
changed into mount options rather than old build configs.

Let's kill useless code for obsoleted build options.

Link: https://lore.kernel.org/r/20191008125616.183715-2-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: clean up collection handling routines

- change return value to int since collection is
already returned within the collector.
- better function naming.

Link: https://lore.kernel.org/r/2

erofs: clean up collection handling routines

- change return value to int since collection is
already returned within the collector.
- better function naming.

Link: https://lore.kernel.org/r/20191008125616.183715-1-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: fix mis-inplace determination related with noio chain

Fix a recent cleanup patch. noio (bypass) chain is
handled asynchronously against submit chain, therefore
inplace I/O or pagevec cannot b

erofs: fix mis-inplace determination related with noio chain

Fix a recent cleanup patch. noio (bypass) chain is
handled asynchronously against submit chain, therefore
inplace I/O or pagevec cannot be applied to such pages.
Add detailed comment for this as well.

Fixes: 97e86a858bc3 ("staging: erofs: tidy up decompression frontend")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190922100434.229340-1-gaoxiang25@huawei.com
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

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erofs: rename errln/infoln/debugln to erofs_{err, info, dbg}

Add prefix "erofs_" to these functions and print
sb->s_id as a prefix to erofs_{err, info} so that
the user knows which file system is af

erofs: rename errln/infoln/debugln to erofs_{err, info, dbg}

Add prefix "erofs_" to these functions and print
sb->s_id as a prefix to erofs_{err, info} so that
the user knows which file system is affected.

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-23-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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