task #27327988

commit 3917c80280c93a7123f1a3a6dcdb10a3ea19737d upstream

Currently we have different copy-on-write semantics for anon- and
file-THP.  For anon-THP we try to allocate huge page on the write fault,
but on file-THP we split PMD and allocate 4k page.

Arguably, file-THP semantics is more desirable: we don't necessary want to
unshare full PMD range from the parent on the first access.  This is the
primary reason THP is unusable for some workloads, like Redis.

The original THP refcounting didn't allow to have PTE-mapped compound
pages, so we had no options, but to allocate huge page on CoW (with
fallback to 512 4k pages).

The current refcounting doesn't have such limitations and we can cut a lot
of complex code out of fault path.

khugepaged is now able to recover THP from such ranges if the
configuration allows.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-8-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #27327988

commit 5503fbf2b0b80c1a47a7dca0e4f060f52f522cfd upstream

We can collapse PTE-mapped compound pages.  We only need to avoid handling
them more than once: lock/unlock page only once if it's present in the PMD
range multiple times as it handled on compound level.  The same goes for
LRU isolation and putback.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-7-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #27327988

commit 9445689f3b6170c6145a8772eee692482199cdd6 upstream

The page can be included into collapse as long as it doesn't have extra
pins (from GUP or otherwise).

Logic to check the refcount is moved to a separate function.  For pages in
swap cache, add compound_nr(page) to the expected refcount, in order to
handle the compound page case.  This is in preparation for the following
patch.

VM_BUG_ON_PAGE() was removed from __collapse_huge_page_copy() as the
invariant it checks is no longer valid: the source can be mapped multiple
times now.

[yang.shi@linux.alibaba.com: remove error message when checking external pins]
  Link: http://lkml.kernel.org/r/1589317383-9595-1-git-send-email-yang.shi@linux.alibaba.com
[cai@lca.pw: fix set-but-not-used warning]
  Link: http://lkml.kernel.org/r/20200521145644.GA6367@ovpn-112-192.phx2.redhat.comSigned-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-6-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #27327988

commit ae2c5d8042426b69c5f4a74296d1a20bb769a8ad upstream

collapse_huge_page() tries to swap in pages that are part of the PMD
range.  Just swapped in page goes though LRU add cache.  The cache gets
extra reference on the page.

The extra reference can lead to the collapse fail: the following
__collapse_huge_page_isolate() would check refcount and abort collapse
seeing unexpected refcount.

The fix is to drain local LRU add cache in
__collapse_huge_page_swapin() if we successfully swapped in any pages.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-5-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #27327988

commit a980df33e9351e5474c06ec0fd96b2f409e2ff22 upstream

Having a page in LRU add cache offsets page refcount and gives
false-negative on PageLRU().  It reduces collapse success rate.

Drain all LRU add caches before scanning.  It happens relatively rare and
should not disturb the system too much.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-4-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #27327988

commit ffe945e633b527d5a4577b42cbadec3c7cbcf096 upstream

__collapse_huge_page_swapin() checks the number of referenced PTE to
decide if the memory range is hot enough to justify swapin.

We have few problems with the approach:

 - It is way too late: we can do the check much earlier and safe time.
   khugepaged_scan_pmd() already knows if we have any pages to swap in
   and number of referenced page.

 - It stops collapse altogether if there's not enough referenced pages,
   not only swappingin.

Fix it by making the right check early. We also can avoid additional
page table scanning if khugepaged_scan_pmd() haven't found any swap
entries.

Fixes: 0db501f7 ("mm, thp: convert from optimistic swapin collapsing to conservative")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-3-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #27327988

commit e0c13f9761df8f97cf5e81495d12ecbc4075684a upstream

Patch series "thp/khugepaged improvements and CoW semantics", v4.

The patchset adds khugepaged selftest (anon-THP only for now), expands
cases khugepaged can handle and switches anon-THP copy-on-write handling
to 4k.

This patch (of 8):

The test checks if khugepaged is able to recover huge page where we expect
to do so.  It only covers anon-THP for now.

Currently the test shows few failures.  They are going to be addressed by
the following patches.

[colin.king@canonical.com: fix several spelling mistakes]
  Link: http://lkml.kernel.org/r/20200420084241.65433-1-colin.king@canonical.com
[aneesh.kumar@linux.ibm.com: replace the usage of system(3) in the test]
  Link: http://lkml.kernel.org/r/20200429110727.89388-1-aneesh.kumar@linux.ibm.com
[kirill@shutemov.name: fixup for issues I've noticed]
  Link: http://lkml.kernel.org/r/20200429124816.jp272trghrzxx5j5@box
[jhubbard@nvidia.com: add khugepaged to .gitignore]
  Link: http://lkml.kernel.org/r/20200517002509.362401-1-jhubbard@nvidia.comSigned-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NZi Yan <ziy@nvidia.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NYang Shi <yang.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Link: http://lkml.kernel.org/r/20200416160026.16538-1-kirill.shutemov@linux.intel.com
Link: http://lkml.kernel.org/r/20200416160026.16538-2-kirill.shutemov@linux.intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #28135435

commit 60858c00e5f018eda711a3aa84cf62214ef62d61 upstream

Assume we have kmem configured and loaded:

  [root@localhost ~]# cat /proc/iomem
  ...
  140000000-33fffffff : Persistent Memory$
    140000000-1481fffff : namespace0.0
    150000000-33fffffff : dax0.0
      150000000-33fffffff : System RAM

Assume we try to unload kmem. This force-unloading will work, even if
memory cannot get removed from the system.

  [root@localhost ~]# rmmod kmem
  [   86.380228] removing memory fails, because memory [0x0000000150000000-0x0000000157ffffff] is onlined
  ...
  [   86.431225] kmem dax0.0: DAX region [mem 0x150000000-0x33fffffff] cannot be hotremoved until the next reboot

Now, we can reconfigure the namespace:

  [root@localhost ~]# ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax
  [  131.409351] nd_pmem namespace0.0: could not reserve region [mem 0x140000000-0x33fffffff]dax
  [  131.410147] nd_pmem: probe of namespace0.0 failed with error -16namespace0.0 --mode=devdax
  ...

This fails as expected due to the busy memory resource, and the memory
cannot be used.  However, the dax0.0 device is removed, and along its
name.

The name of the memory resource now points at freed memory (name of the
device):

  [root@localhost ~]# cat /proc/iomem
  ...
  140000000-33fffffff : Persistent Memory
    140000000-1481fffff : namespace0.0
    150000000-33fffffff : �_�^7_��/_��wR��WQ���^��� ...
    150000000-33fffffff : System RAM

We have to make sure to duplicate the string.  While at it, remove the
superfluous setting of the name and fixup a stale comment.

Fixes: 9f960da72b25 ("device-dax: "Hotremove" persistent memory that is used like normal RAM")
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>	[5.3]
Link: http://lkml.kernel.org/r/20200508084217.9160-2-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Acked-by: NXunlei Pang <xlpang@linux.alibaba.com>

task #28135435

commit 9f960da72b25054163cf555e622dcdc3b8ccc488 upstream

It is now allowed to use persistent memory like a regular RAM, but
currently there is no way to remove this memory until machine is
rebooted.

This work expands the functionality to also allows hotremoving
previously hotplugged persistent memory, and recover the device for use
for other purposes.

To hotremove persistent memory, the management software must first
offline all memory blocks of dax region, and than unbind it from
device-dax/kmem driver.  So, operations should look like this:

  echo offline > /sys/devices/system/memory/memoryN/state
  ...
  echo dax0.0 > /sys/bus/dax/drivers/kmem/unbind

Note: if unbind is done without offlining memory beforehand, it won't be
possible to do dax0.0 hotremove, and dax's memory is going to be part of
System RAM until reboot.

Link: http://lkml.kernel.org/r/20190517215438.6487-4-pasha.tatashin@soleen.comSigned-off-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Acked-by: NXunlei Pang <xlpang@linux.alibaba.com>

fix #28198752

ext4 encryption will increase lock contention when opening directory and
result in performance drop in case will-it-scale open1.
Since we don't have explicit usecases as of now, so we decide to disabed
it.
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: NDust Li <dust.li@linux.alibaba.com>

to #28143829

rq_clock_task is less than rq_clock when in VM, or when IRQ_TIME_ACCOUNTING
is on. So they are not comparable when accounting elapsed time. This bug is
not observed on host yet, because neither of these two conditions are met.

Use rq_clock at both begin and end of exec_start_raw accumulation to fix
this bug, because we expect steal% in cpuacct.proc_stat of VM's cgroups can
reflect the cpu time the host steal from the guest.

Fixes: c7552980 ("alinux: sched: Introduce per-cgroup steal accounting")
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>
Acked-by: NMichael Wang <yun.wang@linux.alibaba.com>

fix #28883562

commit e00d8880481497474792d28c14479a9fb6752046 upstream

Commit c3ff2a5193fa ("powerpc/32: add stack protector support")
caused kernel panic on PowerPC when an external module is used with
CONFIG_STACKPROTECTOR because the 'prepare' target was not executed
for the external module build.

Commit e07db28eea38 ("kbuild: fix single target build for external
module") turned it into a build error because the 'prepare' target is
now executed but the 'prepare0' target is missing for the external
module build.

External module on arm/arm64 with CONFIG_STACKPROTECTOR_PER_TASK is
also broken in the same way.

Move 'PHONY += prepare0' to the common place. GNU Make is fine with
missing rule for phony targets. I also removed the comment which is
wrong irrespective of this commit.

I minimize the change so it can be easily backported to 4.20.x

To fix v4.20, please backport e07db28eea38 ("kbuild: fix single target
build for external module"), and then this commit.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=201891
Fixes: e07db28eea38 ("kbuild: fix single target build for external
module")
Fixes: c3ff2a5193fa ("powerpc/32: add stack protector support")
Fixes: 189af4657186 ("ARM: smp: add support for per-task stack
canaries")
Fixes: 0a1213fa7432 ("arm64: enable per-task stack canaries")
Cc: linux-stable <stable@vger.kernel.org> # v4.20
Reported-by: NSamuel Holland <samuel@sholland.org>
Reported-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NChunmei Xu <xuchunmei@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

fix #28506983

Some ARM machines may have large memory capacity (e.g., more than 256G),
or large hole(s) in memory layout among nodes.

Kernel with CONFIG_ARM64_VA_BITS as 39 has the linear region size as
256G, and the memory that we will not be able to cover with the linear
mapping shall be removed. This may cause part of the physical memory to
become unavailable, system deadlock on memory, or even boot failure, on
such ARM machines.

This changes CONFIG_ARM64_VA_BITS to 48 which supports 128T linear
mapping, in order to adapt to most scenarios.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Reviewed-by: NCaspar Zhang <caspar@linux.alibaba.com>

to #28727280

commit 191941692a3d1b6a9614502b279be062926b70f5 upstream.

Some users prefer kdump tools to generate guest kernel dumpfile,
at the same time, need a out-of-band kernel panic event.

Currently if booting guest kernel with
'crash_kexec_post_notifiers',
QEMU will receive PVPANIC_PANICKED event and stop VM. If booting
guest kernel without 'crash_kexec_post_notifiers', guest will not
call notifier chain.

Add PVPANIC_CRASH_LOADED bit for pvpanic event, it means that guest
kernel actually hit a kernel panic, but the guest kernel wants to
handle by itself.
Signed-off-by: Nzhenwei pi <pizhenwei@bytedance.com>
Link: https://lore.kernel.org/r/20200102023513.318836-3-pizhenwei@bytedance.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 862f35c94730c9270833f3ad05bd758a29f204ed ]

If we just set the mirror count to 1 without first clearing out
the mirrors, we can leak queued up requests.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 8605cf0e852af3b2c771c18417499dc4ceed03d5 ]

When dreq is allocated by nfs_direct_req_alloc(), dreq->kref is
initialized to 2. Therefore we need to call nfs_direct_req_release()
twice to release the allocated dreq. Usually it is called in
nfs_file_direct_{read, write}() and nfs_direct_complete().

However, current code only calls nfs_direct_req_relese() once if
nfs_get_lock_context() fails in nfs_file_direct_{read, write}().
So, that case would result in memory leak.

Fix this by adding the missing call.
Signed-off-by: NMisono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit add42de31721fa29ed77a7ce388674d69f9d31a4 upstream.

When we detach a subrequest from the list, we must also release the
reference it holds to the parent.

Fixes: 5b2b5187 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 55dee1bc0d72877b99805e42e0205087e98b9edd ]

An NFS client that mounts multiple exports from the same NFS
server with higher NFSv4 versions disabled (i.e. 4.2) and without
forcing a specific NFS version results in fscache index cookie
collisions and the following messages:
[  570.004348] FS-Cache: Duplicate cookie detected

Each nfs_client structure should have its own fscache index cookie,
so add the minorversion to nfs_server_key.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=200145Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Signed-off-by: NDave Wysochanski <dwysocha@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 123c23c6a7b7ecd2a3d6060bea1d94019f71fd66 ]

In _nfs42_proc_copy(), 'res->commit_res.verf' is allocated through
kzalloc() if 'args->sync' is true. In the following code, if
'res->synchronous' is false, handle_async_copy() will be invoked. If an
error occurs during the invocation, the following code will not be executed
and the error will be returned . However, the allocated
'res->commit_res.verf' is not deallocated, leading to a memory leak. This
is also true if the invocation of process_copy_commit() returns an error.

To fix the above leaks, redirect the execution to the 'out' label if an
error is encountered.
Signed-off-by: NWenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit 221203ce6406273cf00e5c6397257d986c003ee6 upstream.

Instead of making assumptions about the commit verifier contents, change
the commit code to ensure we always check that the verifier was set
by the XDR code.

Fixes: f54bcf2e ("pnfs: Prepare for flexfiles by pulling out common code")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit 0df68ced55443243951d02cc497be31fadf28173 upstream.

If we suffer a fatal error upon writing a file, which causes us to
need to revalidate the entire mapping, then we should also revalidate
the file size.

Fixes: d2ceb7e57086 ("NFS: Don't use page_file_mapping after removing the page")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit 114de38225d9b300f027e2aec9afbb6e0def154b upstream.

When a NFS directory page cache page is removed from the page cache,
its contents are freed through a call to nfs_readdir_clear_array().
To prevent the removal of the page cache entry until after we've
finished reading it, we must take the page lock.

Fixes: 11de3b11 ("NFS: Fix a memory leak in nfs_readdir")
Cc: stable@vger.kernel.org # v2.6.37+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit 4b310319c6a8ce708f1033d57145e2aa027a883c upstream.

nfs_readdir_xdr_to_array() must not exit without having initialised
the array, so that the page cache deletion routines can safely
call nfs_readdir_clear_array().
Furthermore, we should ensure that if we exit nfs_readdir_filler()
with an error, we free up any page contents to prevent a leak
if we try to fill the page again.

Fixes: 11de3b11 ("NFS: Fix a memory leak in nfs_readdir")
Cc: stable@vger.kernel.org # v2.6.37+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 108bb4afd351d65826648a47f11fa3104e250d9b ]

If the attempt to instantiate the mirror's layout DS pointer failed,
then that pointer may hold a value of type ERR_PTR(), so we need
to check that before we dereference it.

Fixes: 65990d1a ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 1a3466aed3a17eed41cd9411f89eb637f58349b0 ]

These really should have been there from the beginning, but we never
noticed because there was enough slack in the RPC request for the extra
bytes. Chuck's recent patch to use au_cslack and au_rslack to compute
buffer size shrunk the buffer enough that this was now a problem for
SEEK operations on my test client.

Fixes: f4ac1674 ("nfs: Add ALLOCATE support")
Fixes: 2e72448b ("NFS: Add COPY nfs operation")
Fixes: cb95deea ("NFS OFFLOAD_CANCEL xdr")
Fixes: 624bd5b7 ("nfs: Add DEALLOCATE support")
Fixes: 1c6dcbe5 ("NFS: Implement SEEK")
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 5085607d209102b37b169bc94d0aa39566a9842a ]

If a bulk layout recall or a metadata server reboot coincides with a
umount, then holding a reference to an inode is unsafe unless we
also hold a reference to the super block.

Fixes: fd9a8d71 ("NFSv4.1: Fix bulk recall and destroy of layouts")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

[ Upstream commit 6f9449be53f3ce383caed797708b332ede8d952c ]

Fix a soft lockup when NFS client delegation recovery is attempted
but the inode is in the process of being freed. When the
igrab(inode) call fails, and we have to restart the recovery process,
we need to ensure that we won't attempt to recover the same delegation
again.

Fixes: 45870d69 ("NFSv4.1: Test delegation stateids when server...")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit 5326de9e94bedcf7366e7e7625d4deb8c1f1ca8a upstream.

If nfs4_delegreturn_prepare needs to wait for a layoutreturn to complete
then make sure we drop the sequence slot if we hold it.

Fixes: 1c5bd76d ("pNFS: Enable layoutreturn operation for return-on-close")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557789

commit ad97a995d8edff820d4238bd0dfc69f440031ae6 upstream.

Encode the mtime correctly.

Fixes: 95582b00 ("vfs: change inode times to use struct timespec64")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

[ Upstream commit c142932c29e533ee892f87b44d8abc5719edceec ]

In the reflink extent remap function, it turns out that uirec (the block
mapping corresponding only to the part of the passed-in mapping that got
unmapped) was not fully initialized.  Specifically, br_state was not
being copied from the passed-in struct to the uirec.  This could lead to
unpredictable results such as the reflinked mapping being marked
unwritten in the destination file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

commit 10a98cb16d80be3595fdb165fad898bb28b8b6d2 upstream.

Leaving PF_MEMALLOC set when exiting a kthread causes it to remain set
during do_exit().  That can confuse things.  In particular, if BSD
process accounting is enabled, then do_exit() writes data to an
accounting file.  If that file has FS_SYNC_FL set, then this write
occurs synchronously and can misbehave if PF_MEMALLOC is set.

For example, if the accounting file is located on an XFS filesystem,
then a WARN_ON_ONCE() in iomap_do_writepage() is triggered and the data
doesn't get written when it should.  Or if the accounting file is
located on an ext4 filesystem without a journal, then a WARN_ON_ONCE()
in ext4_write_inode() is triggered and the inode doesn't get written.

Fix this in xfsaild() by using the helper functions to save and restore
PF_MEMALLOC.

This can be reproduced as follows in the kvm-xfstests test appliance
modified to add the 'acct' Debian package, and with kvm-xfstests's
recommended kconfig modified to add CONFIG_BSD_PROCESS_ACCT=y:

        mkfs.xfs -f /dev/vdb
        mount /vdb
        touch /vdb/file
        chattr +S /vdb/file
        accton /vdb/file
        mkfs.xfs -f /dev/vdc
        mount /vdc
        umount /vdc

It causes:
	WARNING: CPU: 1 PID: 336 at fs/iomap/buffered-io.c:1534
	CPU: 1 PID: 336 Comm: xfsaild/vdc Not tainted 5.6.0-rc5 #3
	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014
	RIP: 0010:iomap_do_writepage+0x16b/0x1f0 fs/iomap/buffered-io.c:1534
	[...]
	Call Trace:
	 write_cache_pages+0x189/0x4d0 mm/page-writeback.c:2238
	 iomap_writepages+0x1c/0x33 fs/iomap/buffered-io.c:1642
	 xfs_vm_writepages+0x65/0x90 fs/xfs/xfs_aops.c:578
	 do_writepages+0x41/0xe0 mm/page-writeback.c:2344
	 __filemap_fdatawrite_range+0xd2/0x120 mm/filemap.c:421
	 file_write_and_wait_range+0x71/0xc0 mm/filemap.c:760
	 xfs_file_fsync+0x7a/0x2b0 fs/xfs/xfs_file.c:114
	 generic_write_sync include/linux/fs.h:2867 [inline]
	 xfs_file_buffered_aio_write+0x379/0x3b0 fs/xfs/xfs_file.c:691
	 call_write_iter include/linux/fs.h:1901 [inline]
	 new_sync_write+0x130/0x1d0 fs/read_write.c:483
	 __kernel_write+0x54/0xe0 fs/read_write.c:515
	 do_acct_process+0x122/0x170 kernel/acct.c:522
	 slow_acct_process kernel/acct.c:581 [inline]
	 acct_process+0x1d4/0x27c kernel/acct.c:607
	 do_exit+0x83d/0xbc0 kernel/exit.c:791
	 kthread+0xf1/0x140 kernel/kthread.c:257
	 ret_from_fork+0x27/0x50 arch/x86/entry/entry_64.S:352

This bug was originally reported by syzbot at
https://lore.kernel.org/r/0000000000000e7156059f751d7b@google.com.

Reported-by: syzbot+1f9dc49e8de2582d90c2@syzkaller.appspotmail.com
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

commit 4b674b9ac852937af1f8c62f730c325fb6eadcdb upstream.

The filesystem freeze sequence in XFS waits on any background
eofblocks or cowblocks scans to complete before the filesystem is
quiesced. At this point, the freezer has already stopped the
transaction subsystem, however, which means a truncate or cowblock
cancellation in progress is likely blocked in transaction
allocation. This results in a deadlock between freeze and the
associated scanner.

Fix this problem by holding superblock write protection across calls
into the block reapers. Since protection for background scans is
acquired from the workqueue task context, trylock to avoid a similar
deadlock between freeze and blocking on the write lock.

Fixes: d6b636eb ("xfs: halt auto-reclamation activities while rebuilding rmap")
Reported-by: NPaul Furtado <paulfurtado91@gmail.com>
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAllison Collins <allison.henderson@oracle.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

commit bc56ad8c74b8588685c2875de0df8ab6974828ef upstream.

When performing rename operation with RENAME_WHITEOUT flag, we will
hold AGF lock to allocate or free extents in manipulating the dirents
firstly, and then doing the xfs_iunlink_remove() call last to hold
AGI lock to modify the tmpfile info, so we the lock order AGI->AGF.

The big problem here is that we have an ordering constraint on AGF
and AGI locking - inode allocation locks the AGI, then can allocate
a new extent for new inodes, locking the AGF after the AGI. Hence
the ordering that is imposed by other parts of the code is AGI before
AGF. So we get an ABBA deadlock between the AGI and AGF here.

Process A:
Call trace:
 ? __schedule+0x2bd/0x620
 schedule+0x33/0x90
 schedule_timeout+0x17d/0x290
 __down_common+0xef/0x125
 ? xfs_buf_find+0x215/0x6c0 [xfs]
 down+0x3b/0x50
 xfs_buf_lock+0x34/0xf0 [xfs]
 xfs_buf_find+0x215/0x6c0 [xfs]
 xfs_buf_get_map+0x37/0x230 [xfs]
 xfs_buf_read_map+0x29/0x190 [xfs]
 xfs_trans_read_buf_map+0x13d/0x520 [xfs]
 xfs_read_agf+0xa6/0x180 [xfs]
 ? schedule_timeout+0x17d/0x290
 xfs_alloc_read_agf+0x52/0x1f0 [xfs]
 xfs_alloc_fix_freelist+0x432/0x590 [xfs]
 ? down+0x3b/0x50
 ? xfs_buf_lock+0x34/0xf0 [xfs]
 ? xfs_buf_find+0x215/0x6c0 [xfs]
 xfs_alloc_vextent+0x301/0x6c0 [xfs]
 xfs_ialloc_ag_alloc+0x182/0x700 [xfs]
 ? _xfs_trans_bjoin+0x72/0xf0 [xfs]
 xfs_dialloc+0x116/0x290 [xfs]
 xfs_ialloc+0x6d/0x5e0 [xfs]
 ? xfs_log_reserve+0x165/0x280 [xfs]
 xfs_dir_ialloc+0x8c/0x240 [xfs]
 xfs_create+0x35a/0x610 [xfs]
 xfs_generic_create+0x1f1/0x2f0 [xfs]
 ...

Process B:
Call trace:
 ? __schedule+0x2bd/0x620
 ? xfs_bmapi_allocate+0x245/0x380 [xfs]
 schedule+0x33/0x90
 schedule_timeout+0x17d/0x290
 ? xfs_buf_find+0x1fd/0x6c0 [xfs]
 __down_common+0xef/0x125
 ? xfs_buf_get_map+0x37/0x230 [xfs]
 ? xfs_buf_find+0x215/0x6c0 [xfs]
 down+0x3b/0x50
 xfs_buf_lock+0x34/0xf0 [xfs]
 xfs_buf_find+0x215/0x6c0 [xfs]
 xfs_buf_get_map+0x37/0x230 [xfs]
 xfs_buf_read_map+0x29/0x190 [xfs]
 xfs_trans_read_buf_map+0x13d/0x520 [xfs]
 xfs_read_agi+0xa8/0x160 [xfs]
 xfs_iunlink_remove+0x6f/0x2a0 [xfs]
 ? current_time+0x46/0x80
 ? xfs_trans_ichgtime+0x39/0xb0 [xfs]
 xfs_rename+0x57a/0xae0 [xfs]
 xfs_vn_rename+0xe4/0x150 [xfs]
 ...

In this patch we move the xfs_iunlink_remove() call to
before acquiring the AGF lock to preserve correct AGI/AGF locking
order.

[Minor massage required due to upstream change making xfs_bumplink() a
void function where as in the 4.19.y tree the return value is checked,
even though it is always zero. Only change was to the last code block
removed by the patch. Functionally equivalent to upstream.]
Signed-off-by: Nkaixuxia <kaixuxia@tencent.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NSuraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

[ Upstream commit 5d1116d4c6af3e580f1ed0382ca5a94bd65a34cf ]

Christoph Hellwig complained about the following soft lockup warning
when running scrub after generic/175 when preemption is disabled and
slub debugging is enabled:

watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [xfs_scrub:161]
Modules linked in:
irq event stamp: 41692326
hardirqs last  enabled at (41692325): [<ffffffff8232c3b7>] _raw_0
hardirqs last disabled at (41692326): [<ffffffff81001c5a>] trace0
softirqs last  enabled at (41684994): [<ffffffff8260031f>] __do_e
softirqs last disabled at (41684987): [<ffffffff81127d8c>] irq_e0
CPU: 3 PID: 16189 Comm: xfs_scrub Not tainted 5.4.0-rc3+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.124
RIP: 0010:_raw_spin_unlock_irqrestore+0x39/0x40
Code: 89 f3 be 01 00 00 00 e8 d5 3a e5 fe 48 89 ef e8 ed 87 e5 f2
RSP: 0018:ffffc9000233f970 EFLAGS: 00000286 ORIG_RAX: ffffffffff3
RAX: ffff88813b398040 RBX: 0000000000000286 RCX: 0000000000000006
RDX: 0000000000000006 RSI: ffff88813b3988c0 RDI: ffff88813b398040
RBP: ffff888137958640 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00042b0c00
R13: 0000000000000001 R14: ffff88810ac32308 R15: ffff8881376fc040
FS:  00007f6113dea700(0000) GS:ffff88813bb80000(0000) knlGS:00000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6113de8ff8 CR3: 000000012f290000 CR4: 00000000000006e0
Call Trace:
 free_debug_processing+0x1dd/0x240
 __slab_free+0x231/0x410
 kmem_cache_free+0x30e/0x360
 xchk_ag_btcur_free+0x76/0xb0
 xchk_ag_free+0x10/0x80
 xchk_bmap_iextent_xref.isra.14+0xd9/0x120
 xchk_bmap_iextent+0x187/0x210
 xchk_bmap+0x2e0/0x3b0
 xfs_scrub_metadata+0x2e7/0x500
 xfs_ioc_scrub_metadata+0x4a/0xa0
 xfs_file_ioctl+0x58a/0xcd0
 do_vfs_ioctl+0xa0/0x6f0
 ksys_ioctl+0x5b/0x90
 __x64_sys_ioctl+0x11/0x20
 do_syscall_64+0x4b/0x1a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

If preemption is disabled, all metadata buffers needed to perform the
scrub are already in memory, and there are a lot of records to check,
it's possible that the scrub thread will run for an extended period of
time without sleeping for IO or any other reason.  Then the watchdog
timer or the RCU stall timeout can trigger, producing the backtrace
above.

To fix this problem, call cond_resched() from the scrub thread so that
we back out to the scheduler whenever necessary.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

commit 69ffe5960df16938bccfe1b65382af0b3de51265 upstream.

Commit 5b094d6d ("xfs: fix multi-AG deadlock in xfs_bunmapi") added
a check in __xfs_bunmapi() to stop early if we would touch multiple AGs
in the wrong order. However, this check isn't applicable for realtime
files. In most cases, it just makes us do unnecessary commits. However,
without the fix from the previous commit ("xfs: fix realtime file data
space leak"), if the last and second-to-last extents also happen to have
different "AG numbers", then the break actually causes __xfs_bunmapi()
to return without making any progress, which sends
xfs_itruncate_extents_flags() into an infinite loop.

Fixes: 5b094d6d ("xfs: fix multi-AG deadlock in xfs_bunmapi")
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557760

[ Upstream commit 798a9cada4694ca8d970259f216cec47e675bfd5 ]

syzbot (via KASAN) reports a use-after-free in the error path of
xlog_alloc_log(). Specifically, the iclog freeing loop doesn't
handle the case of a fully initialized ->l_iclog linked list.
Instead, it assumes that the list is partially constructed and NULL
terminated.

This bug manifested because there was no possible error scenario
after iclog list setup when the original code was added.  Subsequent
code and associated error conditions were added some time later,
while the original error handling code was never updated. Fix up the
error loop to terminate either on a NULL iclog or reaching the end
of the list.

Reported-by: syzbot+c732f8644185de340492@syzkaller.appspotmail.com
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557782

commit 300b124fcf6ad2cd99a7b721e0f096785e0a3134 upstream.

Commit 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more
cases"), relaxed the condition nfs_export=on in order to set the value of
i_ino to xino map of real ino.

Specifically, it also relaxed the pre-condition that index=on for
consistent i_ino. This opened the corner case of lower hardlink in
ovl_get_inode(), which calls ovl_fill_inode() with ino=0 and then
ovl_init_inode() is called to set i_ino to lower real ino without the xino
mapping.

Pass the correct values of ino;fsid in this case to ovl_fill_inode(), so it
can initialize i_ino correctly.

Fixes: 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more ...")
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557782

[ Upstream commit a4ac9d45c0cd14a2adc872186431c79804b77dbf ]

ovl_lseek() is using ssize_t to return the value from vfs_llseek().  On a
32-bit kernel ssize_t is a 32-bit signed int, which overflows above 2 GB.

Assign the return value of vfs_llseek() to loff_t to fix this.
Reported-by: NBoris Gjenero <boris.gjenero@gmail.com>
Fixes: 9e46b840c705 ("ovl: support stacked SEEK_HOLE/SEEK_DATA")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557737

[ Upstream commit 6c5d911249290f41f7b50b43344a7520605b1acb ]

journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NQian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pwSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

task #28557737

commit 8eedabfd66b68a4623beec0789eac54b8c9d0fb6 upstream.

I found a NULL pointer dereference in ocfs2_block_group_clear_bits().
The running environment:
	kernel version: 4.19
	A cluster with two nodes, 5 luns mounted on two nodes, and do some
	file operations like dd/fallocate/truncate/rm on every lun with storage
	network disconnection.

The fallocate operation on dm-23-45 caused an null pointer dereference.

The information of NULL pointer dereference as follows:
	[577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
	[577992.878290] Aborting journal on device dm-23-45.
	...
	[577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
	[577992.890908] __journal_remove_journal_head: freeing b_committed_data
	[577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
	[577992.890918] __journal_remove_journal_head: freeing b_committed_data
	[577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
	[577992.890922] __journal_remove_journal_head: freeing b_committed_data
	[577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
	[577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
	[577992.890928] __journal_remove_journal_head: freeing b_committed_data
	[577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
	[577992.890933] __journal_remove_journal_head: freeing b_committed_data
	[577992.890939] __journal_remove_journal_head: freeing b_committed_data
	[577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
	[577992.890950] Mem abort info:
	[577992.890951]   ESR = 0x96000004
	[577992.890952]   Exception class = DABT (current EL), IL = 32 bits
	[577992.890952]   SET = 0, FnV = 0
	[577992.890953]   EA = 0, S1PTW = 0
	[577992.890954] Data abort info:
	[577992.890955]   ISV = 0, ISS = 0x00000004
	[577992.890956]   CM = 0, WnR = 0
	[577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
	[577992.890960] [0000000000000020] pgd=0000000000000000
	[577992.890964] Internal error: Oops: 96000004 [#1] SMP
	[577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
	[577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G        W  OE     4.19.36 #1
	[577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
	[577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
	[577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
	[577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
	[577992.891084] sp : ffff0000c8e2b810
	[577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
	[577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
	[577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
	[577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
	[577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
	[577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
	[577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
	[577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
	[577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
	[577992.891103] x11: 0000000000000038 x10: 0101010101010101
	[577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
	[577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
	[577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
	[577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
	[577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
	[577992.891116] Call trace:
	[577992.891139]  _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
	[577992.891162]  _ocfs2_free_clusters+0x100/0x290 [ocfs2]
	[577992.891185]  ocfs2_free_clusters+0x50/0x68 [ocfs2]
	[577992.891206]  ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
	[577992.891227]  ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
	[577992.891248]  ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
	[577992.891269]  ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
	[577992.891290]  __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
	[577992.891309]  ocfs2_fallocate+0xe4/0x128 [ocfs2]
	[577992.891316]  vfs_fallocate+0x11c/0x250
	[577992.891317]  ksys_fallocate+0x54/0x88
	[577992.891319]  __arm64_sys_fallocate+0x28/0x38
	[577992.891323]  el0_svc_common+0x78/0x130
	[577992.891325]  el0_svc_handler+0x38/0x78
	[577992.891327]  el0_svc+0x8/0xc

My analysis process as follows:
ocfs2_fallocate
  __ocfs2_change_file_space
    ocfs2_allocate_extents
      ocfs2_extend_allocation
        ocfs2_add_inode_data
          ocfs2_add_clusters_in_btree
            ocfs2_insert_extent
              ocfs2_do_insert_extent
                ocfs2_rotate_tree_right
                  ocfs2_extend_rotate_transaction
                    ocfs2_extend_trans
                      jbd2_journal_restart
                        jbd2__journal_restart
                          /* handle->h_transaction is NULL,
                           * is_handle_aborted(handle) is true
                           */
                          handle->h_transaction = NULL;
                          start_this_handle
                            return -EROFS;
            ocfs2_free_clusters
              _ocfs2_free_clusters
                _ocfs2_free_suballoc_bits
                  ocfs2_block_group_clear_bits
                    ocfs2_journal_access_gd
                      __ocfs2_journal_access
                        jbd2_journal_get_undo_access
                          /* I think jbd2_write_access_granted() will
                           * return true, because do_get_write_access()
                           * will return -EROFS.
                           */
                          if (jbd2_write_access_granted(...)) return 0;
                          do_get_write_access
                            /* handle->h_transaction is NULL, it will
                             * return -EROFS here, so do_get_write_access()
                             * was not called.
                             */
                            if (is_handle_aborted(handle)) return -EROFS;
                    /* bh2jh(group_bh) is NULL, caused NULL
                       pointer dereference */
                    undo_bg = (struct ocfs2_group_desc *)
                                bh2jh(group_bh)->b_committed_data;

If handle->h_transaction == NULL, then jbd2_write_access_granted()
does not really guarantee that journal_head will stay around,
not even speaking of its b_committed_data. The bh2jh(group_bh)
can be removed after ocfs2_journal_access_gd() and before call
"bh2jh(group_bh)->b_committed_data". So, we should move
is_handle_aborted() check from do_get_write_access() into
jbd2_journal_get_undo_access() and jbd2_journal_get_write_access()
before the call to jbd2_write_access_granted().

Link: https://lore.kernel.org/r/f72a623f-b3f1-381a-d91d-d22a1c83a336@huawei.comSigned-off-by: NYan Wang <wangyan122@huawei.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJun Piao <piaojun@huawei.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>