Patch series "mm: introduce shrinker debugfs interface", v5.

The only existing debugging mechanism is a couple of tracepoints in
do_shrink_slab(): mm_shrink_slab_start and mm_shrink_slab_end.  They
aren't covering everything though: shrinkers which report 0 objects will
never show up, there is no support for memcg-aware shrinkers.  Shrinkers
are identified by their scan function, which is not always enough (e.g. 
hard to guess which super block's shrinker it is having only
"super_cache_scan").

To provide a better visibility and debug options for memory shrinkers this
patchset introduces a /sys/kernel/debug/shrinker interface, to some extent
similar to /sys/kernel/slab.

For each shrinker registered in the system a directory is created.  As
now, the directory will contain only a "scan" file, which allows to get
the number of managed objects for each memory cgroup (for memcg-aware
shrinkers) and each numa node (for numa-aware shrinkers on a numa
machine).  Other interfaces might be added in the future.

To make debugging more pleasant, the patchset also names all shrinkers, so
that debugfs entries can have meaningful names.


This patch (of 5):

Shrinker debugfs requires a way to represent memory cgroups without using
full paths, both for displaying information and getting input from a user.

Cgroup inode number is a perfect way, already used by bpf.

This commit adds a couple of helper functions which will be used to handle
memcg-aware shrinkers.

Link: https://lkml.kernel.org/r/20220601032227.4076670-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20220601032227.4076670-2-roman.gushchin@linux.devSigned-off-by: NRoman Gushchin <roman.gushchin@linux.dev>
Acked-by: NMuchun Song <songmuchun@bytedance.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a
page potentially tagged by KASAN.

This helper is used by the following patch.

Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The function for knowing if given monitoring context's targets will have
pid or not is defined and used in dbgfs only.  However, the logic is also
needed for sysfs.  This commit moves the code to damon.h and makes both
dbgfs and sysfs to use it.

Link: https://lkml.kernel.org/r/20220606182310.48781-3-sj@kernel.orgSigned-off-by: NSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

__migration_entry_wait and migration_entry_wait_on_locked assume pte is
always mapped from caller.  But this is not the case when it's called from
migration_entry_wait_huge and follow_huge_pmd.  Add a hugetlbfs variant
that calls hugetlb_migration_entry_wait(ptep == NULL) to fix this issue.

Link: https://lkml.kernel.org/r/20220530113016.16663-5-linmiaohe@huawei.com
Fixes: 30dad309 ("mm: migration: add migrate_entry_wait_huge()")
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Suggested-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

We might fail to isolate huge page due to e.g.  the page is under
migration which cleared HPageMigratable.  We should return errno in this
case rather than always return 1 which could confuse the user, i.e.  the
caller might think all of the memory is migrated while the hugetlb page is
left behind.  We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.

Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com
Fixes: e8db67eb ("mm: migrate: move_pages() supports thp migration")
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Suggested-by: NHuang Ying <ying.huang@intel.com>
Reported-by: kernel test robot <lkp@intel.com> (build error)
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

IIUC page_vma_mapped_walk() checks if the vma is possibly huge PMD mapped
with transparent_hugepage_active() and "pvmw->nr_pages >= HPAGE_PMD_NR".

Actually pvmw->nr_pages is returned by compound_nr() or folio_nr_pages(),
so the page should be THP as long as "pvmw->nr_pages >= HPAGE_PMD_NR". 
And it is guaranteed THP is allocated for valid VMA in the first place. 
But it may be not PMD mapped if the VMA is file VMA and it is not properly
aligned.  The transhuge_vma_suitable() is used to do such check, so
replace transparent_hugepage_active() to it, which is too heavy and
overkilling.

Link: https://lkml.kernel.org/r/20220513191705.457775-1-shy828301@gmail.comSigned-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NMuchun Song <songmuchun@bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The parameter used by DEFINE_PAGE_VMA_WALK is _page not page, fix the
parameter name.  It didn't cause any build error, it is probably because
the only caller is write_protect_page() from ksm.c, which pass in page.

Link: https://lkml.kernel.org/r/20220512174551.81279-1-shy828301@gmail.com
Fixes: 2aff7a47 ("mm: Convert page_vma_mapped_walk to work on PFNs")
Signed-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NMuchun Song <songmuchun@bytedance.com>
Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

so it will be consistent with code mm directory and with
Documentation/admin-guide/mm and won't be confused with virtual machines.
Signed-off-by: NMike Rapoport <rppt@linux.ibm.com>
Suggested-by: NMatthew Wilcox <willy@infradead.org>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Acked-by: NJonathan Corbet <corbet@lwn.net>
Acked-by: NWu XiangCheng <bobwxc@email.cn>

Commit 48ec13d3 ("gpio: Properly document parent data union")
is supposed to have fixed a warning from "make htmldocs" regarding
kernel-doc comments to union members.  However, the same warning
still remains [1].

Fix the issue by following the example found in section "Nested
structs/unions" of Documentation/doc-guide/kernel-doc.rst.
Signed-off-by: NAkira Yokosawa <akiyks@gmail.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Fixes: 48ec13d3 ("gpio: Properly document parent data union")
Link: https://lore.kernel.org/r/20220606093302.21febee3@canb.auug.org.au/ [1]
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Tested-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: NMauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>

This reverts commit 2bb2b7b5.

The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.

It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.

printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.

Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alleySigned-off-by: NPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220623145157.21938-7-pmladek@suse.com

This reverts commit 09c5ba0a.

This reverts commit b87f0230.

The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.

It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.

printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.

Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alleySigned-off-by: NPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220623145157.21938-6-pmladek@suse.com

This reverts commit 8e274732.

The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.

It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.

printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.

Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alleySigned-off-by: NPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220623145157.21938-5-pmladek@suse.com

This reverts commit b87f0230.

The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.

It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.

printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.

Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alleySigned-off-by: NPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220623145157.21938-2-pmladek@suse.com

The TP_printk macro's are not supposed to use custom code ([1]) or else
tools such as perf cannot use these events.

Convert the opcode string representation to use the __string wiring that
the event framework provides ([2]).

[1]: https://lwn.net/Articles/379903/
[2]: https://lwn.net/Articles/381064/

Fixes: 033b87d2 ("io_uring: use the text representation of ops in trace")
Signed-off-by: NDylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220623083743.2648321-1-dylany@fb.com
[axboe: fixup spurious removal of sq_thread assignment]
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Adjust the values of NVME_CAP_CRMS_CRIMS and NVME_CAP_CRMS_CRWMS masks as
they are different from the ones in TP4084 - Time-to-ready.

Fixes: 354201c5 ("nvme: add support for TP4084 - Time-to-Ready Enhancements").
Signed-off-by: NJoel Granados <j.granados@samsung.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Commit 8a59f9d1 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()")
has moved the inet_csk_has_ulp(sk) check from sk_psock_init() to
the new tcp_bpf_update_proto() function. I'm guessing that this
was done to allow creating psocks for non-inet sockets.

Unfortunately the destruction path for psock includes the ULP
unwind, so we need to fail the sk_psock_init() itself.
Otherwise if ULP is already present we'll notice that later,
and call tcp_update_ulp() with the sk_proto of the ULP
itself, which will most likely result in the ULP looping
its callbacks.

Fixes: 8a59f9d1 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()")
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NJohn Fastabend <john.fastabend@gmail.com>
Reviewed-by: NJakub Sitnicki <jakub@cloudflare.com>
Tested-by: NJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20220620191353.1184629-2-kuba@kernel.orgSigned-off-by: NPaolo Abeni <pabeni@redhat.com>

Move load_certificate_list(), which loads a series of binary X.509
certificates from a blob and inserts them as keys into a keyring, to be
with the asymmetric keys code that it drives.

This makes it easier to add FIPS selftest code in which we need to load up
a private keyring for the tests to use.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NSimo Sorce <simo@redhat.com>
Reviewed-by: NHerbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
Link: https://lore.kernel.org/r/165515742145.1554877.13488098107542537203.stgit@warthog.procyon.org.uk/

The request queue pointer in struct blk_independent_access_range is
unused. Remove it.
Signed-off-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Fixes: 41e46b3c ("block: Fix potential deadlock in blk_ia_range_sysfs_show()")
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220603053529.76405-1-damien.lemoal@opensource.wdc.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

random.c ratelimits how much it warns about uninitialized urandom reads
using __ratelimit(). When the RNG is finally initialized, it prints the
number of missed messages due to ratelimiting.

It has been this way since that functionality was introduced back in
2018. Recently, cc1e127b ("random: remove ratelimiting for in-kernel
unseeded randomness") put a bit more stress on the urandom ratelimiting,
which teased out a bug in the implementation.

Specifically, when under pressure, __ratelimit() will print its own
message and reset the count back to 0, making the final message at the
end less useful. Secondly, it does so as a pr_warn(), which apparently
is undesirable for people's CI.

Fortunately, __ratelimit() has the RATELIMIT_MSG_ON_RELEASE flag exactly
for this purpose, so we set the flag.

Fixes: 4e00b339 ("random: rate limit unseeded randomness warnings")
Cc: stable@vger.kernel.org
Reported-by: NJon Hunter <jonathanh@nvidia.com>
Reported-by: NRon Economos <re@w6rz.net>
Tested-by: NRon Economos <re@w6rz.net>
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>

Various places like I/O schedulers or the QOS infrastructure try to
register debugfs files on demans, which can race with creating and
removing the main queue debugfs directory.  Use the existing
debugfs_mutex to serialize all debugfs operations that rely on
q->debugfs_dir or the directories hanging off it.

To make the teardown code a little simpler declare all debugfs dentry
pointers and not just the main one uncoditionally in blkdev.h.

Move debugfs_mutex next to the dentries that it protects and document
what it is used for.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220614074827.458955-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add flags value to check the result of ata completion

Fixes: 255c03d1 ("libata: Add tracepoints")
Cc: stable@vger.kernel.org
Signed-off-by: NEdward Wu <edwardwu@realtek.com>
Signed-off-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>

__register_pernet_operations() executes init hook of registered
pernet_operation structure in all existing net namespaces.

Typically, these hooks are called by a process associated with the
specified net namespace, and all __GFP_ACCOUNT marked allocation are
accounted for corresponding container/memcg.

However __register_pernet_operations() calls the hooks in the same
context, and as a result all marked allocations are accounted to one memcg
for all processed net namespaces.

This patch adjusts active memcg for each net namespace and helps to
account memory allocated inside ops_init() into the proper memcg.

Link: https://lkml.kernel.org/r/f9394752-e272-9bf9-645f-a18c56d1c4ec@openvz.orgSigned-off-by: NVasily Averin <vvs@openvz.org>
Acked-by: NRoman Gushchin <roman.gushchin@linux.dev>
Acked-by: NShakeel Butt <shakeelb@google.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Linux Kernel Functional Testing <lkft@linaro.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Currently mem_cgroup_from_obj() is not working properly with objects
allocated using vmalloc().  It creates problems in some cases, when it's
called for static objects belonging to modules or generally allocated
using vmalloc().

This patch makes mem_cgroup_from_obj() safe to be called on objects
allocated using vmalloc().

It also introduces mem_cgroup_from_slab_obj(), which is a faster version
to use in places when we know the object is either a slab object or a
generic slab page (e.g.  when adding an object to a lru list).

Link: https://lkml.kernel.org/r/20220610180310.1725111-1-roman.gushchin@linux.devSuggested-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NRoman Gushchin <roman.gushchin@linux.dev>
Tested-by: NLinux Kernel Functional Testing <lkft@linaro.org>
Acked-by: NShakeel Butt <shakeelb@google.com>
Tested-by: NVasily Averin <vvs@openvz.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMuchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Patch series "mm: kmemleak: store objects allocated with physical address
separately and check when scan", v4.

The kmemleak_*_phys() interface uses "min_low_pfn" and "max_low_pfn" to
check address.  But on some architectures, kmemleak_*_phys() is called
before those two variables initialized.  The following steps will be
taken:

1) Add OBJECT_PHYS flag and rbtree for the objects allocated
   with physical address
2) Store physical address in objects if allocated with OBJECT_PHYS
3) Check the boundary when scan instead of in kmemleak_*_phys()

This patch set will solve:
https://lore.kernel.org/r/20220527032504.30341-1-yee.lee@mediatek.com
https://lore.kernel.org/r/9dd08bb5-f39e-53d8-f88d-bec598a08c93@gmail.com

v3: https://lore.kernel.org/r/20220609124950.1694394-1-patrick.wang.shcn@gmail.com
v2: https://lore.kernel.org/r/20220603035415.1243913-1-patrick.wang.shcn@gmail.com
v1: https://lore.kernel.org/r/20220531150823.1004101-1-patrick.wang.shcn@gmail.com


This patch (of 4):

Remove the unused kmemleak_not_leak_phys() function.  And remove the
min_count argument to kmemleak_alloc_phys() function, assume it's 0.

Link: https://lkml.kernel.org/r/20220611035551.1823303-1-patrick.wang.shcn@gmail.com
Link: https://lkml.kernel.org/r/20220611035551.1823303-2-patrick.wang.shcn@gmail.comSigned-off-by: NPatrick Wang <patrick.wang.shcn@gmail.com>
Suggested-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Yee Lee <yee.lee@mediatek.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Matthew Wilcox reported that, while he was looking at memmove_page(), he
realized that it can't actually work.

The reasons are hidden in its implementation, which makes use of memmove()
on logical addresses provided by kmap_local_page().  memmove() does the
wrong thing when it tests "if (dest <= src)".

Therefore, delete memmove_page().

No need to change any other code because we have no call sites of
memmove_page() across the whole kernel.

Link: https://lkml.kernel.org/r/20220606141533.555-1-fmdefrancesco@gmail.comSigned-off-by: NFabio M. De Francesco <fmdefrancesco@gmail.com>
Reported-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Since commit 0f91d133 ("mm/damon: simplify stop mechanism") delete
kdamond_stop and change to use kthread stop mechanism, these obsolete
comments should be removed accordingly.

Link: https://lkml.kernel.org/r/20220531020421.46849-1-zhouchengming@bytedance.comSigned-off-by: NChengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: NSeongJae Park <sj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

I observed that for each of the shared file-backed page faults, we're very
likely to retry one more time for the 1st write fault upon no page.  It's
because we'll need to release the mmap lock for dirty rate limit purpose
with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()).

Then after that throttling we return VM_FAULT_RETRY.

We did that probably because VM_FAULT_RETRY is the only way we can return
to the fault handler at that time telling it we've released the mmap lock.

However that's not ideal because it's very likely the fault does not need
to be retried at all since the pgtable was well installed before the
throttling, so the next continuous fault (including taking mmap read lock,
walk the pgtable, etc.) could be in most cases unnecessary.

It's not only slowing down page faults for shared file-backed, but also add
more mmap lock contention which is in most cases not needed at all.

To observe this, one could try to write to some shmem page and look at
"pgfault" value in /proc/vmstat, then we should expect 2 counts for each
shmem write simply because we retried, and vm event "pgfault" will capture
that.

To make it more efficient, add a new VM_FAULT_COMPLETED return code just to
show that we've completed the whole fault and released the lock.  It's also
a hint that we should very possibly not need another fault immediately on
this page because we've just completed it.

This patch provides a ~12% perf boost on my aarch64 test VM with a simple
program sequentially dirtying 400MB shmem file being mmap()ed and these are
the time it needs:

  Before: 650.980 ms (+-1.94%)
  After:  569.396 ms (+-1.38%)

I believe it could help more than that.

We need some special care on GUP and the s390 pgfault handler (for gmap
code before returning from pgfault), the rest changes in the page fault
handlers should be relatively straightforward.

Another thing to mention is that mm_account_fault() does take this new
fault as a generic fault to be accounted, unlike VM_FAULT_RETRY.

I explicitly didn't touch hmm_vma_fault() and break_ksm() because they do
not handle VM_FAULT_RETRY even with existing code, so I'm literally keeping
them as-is.

Link: https://lkml.kernel.org/r/20220530183450.42886-1-peterx@redhat.comSigned-off-by: NPeter Xu <peterx@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NVineet Gupta <vgupta@kernel.org>
Acked-by: NGuo Ren <guoren@kernel.org>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Acked-by: NChristian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NAlistair Popple <apopple@nvidia.com>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>	[arm part]
Acked-by: NHeiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Will Deacon <will@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Helge Deller <deller@gmx.de>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Currently unpoison_memory(unsigned long pfn) is designed for soft
poison(hwpoison-inject) only.  Since 17fae129, the KPTE gets cleared
on a x86 platform once hardware memory corrupts.

Unpoisoning a hardware corrupted page puts page back buddy only, the
kernel has a chance to access the page with *NOT PRESENT* KPTE.  This
leads BUG during accessing on the corrupted KPTE.

Suggested by David&Naoya, disable unpoison mechanism when a real HW error
happens to avoid BUG like this:

 Unpoison: Software-unpoisoned page 0x61234
 BUG: unable to handle page fault for address: ffff888061234000
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 2c01067 P4D 2c01067 PUD 107267063 PMD 10382b063 PTE 800fffff9edcb062
 Oops: 0002 [#1] PREEMPT SMP NOPTI
 CPU: 4 PID: 26551 Comm: stress Kdump: loaded Tainted: G   M       OE     5.18.0.bm.1-amd64 #7
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
 RIP: 0010:clear_page_erms+0x7/0x10
 Code: ...
 RSP: 0000:ffffc90001107bc8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000901 RCX: 0000000000001000
 RDX: ffffea0001848d00 RSI: ffffea0001848d40 RDI: ffff888061234000
 RBP: ffffea0001848d00 R08: 0000000000000901 R09: 0000000000001276
 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
 R13: 0000000000000000 R14: 0000000000140dca R15: 0000000000000001
 FS:  00007fd8b2333740(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff888061234000 CR3: 00000001023d2005 CR4: 0000000000770ee0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  <TASK>
  prep_new_page+0x151/0x170
  get_page_from_freelist+0xca0/0xe20
  ? sysvec_apic_timer_interrupt+0xab/0xc0
  ? asm_sysvec_apic_timer_interrupt+0x1b/0x20
  __alloc_pages+0x17e/0x340
  __folio_alloc+0x17/0x40
  vma_alloc_folio+0x84/0x280
  __handle_mm_fault+0x8d4/0xeb0
  handle_mm_fault+0xd5/0x2a0
  do_user_addr_fault+0x1d0/0x680
  ? kvm_read_and_reset_apf_flags+0x3b/0x50
  exc_page_fault+0x78/0x170
  asm_exc_page_fault+0x27/0x30

Link: https://lkml.kernel.org/r/20220615093209.259374-2-pizhenwei@bytedance.com
Fixes: 847ce401 ("HWPOISON: Add unpoisoning support")
Fixes: 17fae129 ("x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned")
Signed-off-by: Nzhenwei pi <pizhenwei@bytedance.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NNaoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>	[5.8+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The commit referenced below subtly and inadvertently changed the logic to
disallow pinning of zero pfns.  This breaks device assignment with vfio
and potentially various other users of gup.  Exclude the zero page test
from the negation.

Link: https://lkml.kernel.org/r/165490039431.944052.12458624139225785964.stgit@omen
Fixes: 1c563432 ("mm: fix is_pinnable_page against a cma page")
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Reported-by: NYishai Hadas <yishaih@nvidia.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: John Dias <joaodias@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

q->elevator is referred in blk_mq_has_sqsched() without any protection,
no .q_usage_counter is held, no queue srcu and rcu read lock is held,
so potential use-after-free may be triggered.

Fix the issue by adding one queue flag for checking if the elevator
uses single queue style dispatch. Meantime the elevator feature flag
of ELEVATOR_F_MQ_AWARE isn't needed any more.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220616014401.817001-3-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

This reverts:

commit d5a42de8 ("net: Add a second bind table hashed by port and address")
commit 538aaf9b ("selftests: Add test for timing a bind request to a port with a populated bhash entry")
Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/

There are a few things that need to be fixed here:
* Updating bhash2 in cases where the socket's rcv saddr changes
* Adding bhash2 hashbucket locks

Links to syzbot reports:
https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/
https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/

Fixes: d5a42de8 ("net: Add a second bind table hashed by port and address")
Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com
Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com
Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com
Signed-off-by: NJoanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

noop_backing_dev_info is used by superblocks of various
pseudofilesystems such as kdevtmpfs. After commit 10e14073
("writeback: Fix inode->i_io_list not be protected by inode->i_lock
error") this broke because __mark_inode_dirty() started to access more
fields from noop_backing_dev_info and this led to crashes inside
locked_inode_to_wb_and_lock_list() called from __mark_inode_dirty().
Fix the problem by initializing noop_backing_dev_info before the
filesystems get mounted.

Fixes: 10e14073 ("writeback: Fix inode->i_io_list not be protected by inode->i_lock error")
Reported-and-tested-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Reported-and-tested-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Reported-and-tested-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

There are reports that the console kthreads block the global console
lock when the system is going down, for example, reboot, panic.

First part of the solution was to block kthreads in these problematic
system states so they stopped handling newly added messages.

Second part of the solution is to wait when for the kthreads when
they are actively printing. It solves the problem when a message
was printed before the system entered the problematic state and
the kthreads managed to step in.

A busy waiting has to be used because panic() can be called in any
context and in an unknown state of the scheduler.

There must be a timeout because the kthread might get stuck or sleeping
and never release the lock. The timeout 10s is an arbitrary value
inspired by the softlockup timeout.

Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1
Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.comSigned-off-by: NPetr Mladek <pmladek@suse.com>
Tested-by: NPaul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220615162805.27962-3-pmladek@suse.com

Commit e81fb419 ("netfs: Further cleanups after struct netfs_inode
wrapper introduced") changed the argument types and names, and actually
updated the comment too (although that was thanks to David Howells, not
me: my original patch only changed the code).

But the comment fixup didn't go quite far enough, and didn't change the
argument name in the comment, resulting in

  include/linux/netfs.h:314: warning: Function parameter or member 'ctx' not described in 'netfs_inode_init'
  include/linux/netfs.h:314: warning: Excess function parameter 'inode' description in 'netfs_inode_init'

during htmldoc generation.

Fixes: e81fb419 ("netfs: Further cleanups after struct netfs_inode wrapper introduced")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This partially reverts a7c41b46

Even though IORING_CLOSE_FD_AND_FILE_SLOT might save cycles for some
users, but it tries to do two things at a time and it's not clear how to
handle errors and what to return in a single result field when one part
fails and another completes well. Kill it for now.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/837c745019b3795941eee4fcfd7de697886d645b.1655224415.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The resource must be on the LRU before ttm_lru_bulk_move_add() is called
and we need to check if the BO is pinned or not before adding it.

Additional to that we missed taking the LRU spinlock in ttm_bo_unpin().
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NArunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Acked-by: NLuben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220613080816.4965-1-christian.koenig@amd.com
Fixes: fee2ede1 ("drm/ttm: rework bulk move handling v5")

vmalloc does not allocate a vm_struct for vm_map_ram() areas.  That causes
us to deny usercopies from those areas.  This affects XFS which uses
vm_map_ram() for its directories.

Fix this by calling find_vmap_area() instead of find_vm_area().

Fixes: 0aef499f ("mm/usercopy: Detect vmalloc overruns")
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NUladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: NZorro Lang <zlang@redhat.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220612213227.3881769-2-willy@infradead.org

The syntax without dots is available since commit 43756e34
("scripts/kernel-doc: Add support for named variable macro arguments").

The same HTML output is produced with and without this patch.
Signed-off-by: NJonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NTejun Heo <tj@kernel.org>

The netfs_io_request cleanup op is now always in a position to be given a
pointer to a netfs_io_request struct, so this can be passed in instead of
the mapping and private data arguments (both of which are included in the
struct).

So rename the ->cleanup op to ->free_request (to match ->init_request) and
pass in the I/O pointer.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com

Change the signature of netfs helper functions to take a struct netfs_inode
pointer rather than a struct inode pointer where appropriate, thereby
relieving the need for the network filesystem to convert its internal inode
format down to the VFS inode only for netfslib to bounce it back up.  For
type safety, it's better not to do that (and it's less typing too).

Give netfs_write_begin() an extra argument to pass in a pointer to the
netfs_inode struct rather than deriving it internally from the file
pointer.  Note that the ->write_begin() and ->write_end() ops are intended
to be replaced in the future by netfslib code that manages this without the
need to call in twice for each page.

netfs_readpage() and similar are intended to be pointed at directly by the
address_space_operations table, so must stick to the signature dictated by
the function pointers there.

Changes
=======
- Updated the kerneldoc comments and documentation [DH].
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/CAHk-=wgkwKyNmNdKpQkqZ6DnmUL-x9hp0YBnUGjaPFEAdxDTbw@mail.gmail.com/