As call read_mmp_block pass bh_check which value is NULL, then call
sb_getblk to get buffer_head. But mmp_block's buffer_head is already exist
 which also is uptodate. Lead to compare the same data.

Signed-off-by: Ye Bin <yebin10@huawei.com>

This patch is according to Jan Kara's suggestion:
I guess I would just get rid of sb_getblk() in read_mmp_block() and always
expect valid bh passed. The only place that passes NULL bh after this
patch is one case in ext4_multi_mount_protect() and that can call
sb_getblk() on its own. That way we can also simplify read_mmp_block()
prototype to:

static int read_mmp_block(struct super_block *sb, struct buffer_head *bh);

Signed-off-by: Ye Bin <yebin10@huawei.com>

There is only pass NULL 'bh' in ext4_multi_mount_protect,
So just call sb_getblk get buffer head fisrt, and we will
simplify read_mmp_block function.

Signed-off-by: Ye Bin <yebin10@huawei.com>

As mmp and check_mmp is point to the same data, so there will never
detect conflict.
To solve this issue just compare to local data.

Signed-off-by: Ye Bin <yebin10@huawei.com>

If two host have the same nodename, and seq start from 0, May cause the
detection mechanism to fail.
So init 'seq' with the value which set in 'ext4_multi_mount_protect' to
accelerate conflict detection.

Signed-off-by: Ye Bin <yebin10@huawei.com>

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

These are only used in built-in core mm code.

Link: https://lkml.kernel.org/r/20210820095815.445392-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Patch series "unexport memcg locking helpers".

Neither the old page-based nor the new folio-based memcg locking helpers
are used in modular code at all, so drop the exports.

This patch (of 2):

folio_memcg_{,un}lock are only used in built-in core mm code.

Link: https://lkml.kernel.org/r/20210820095815.445392-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210820095815.445392-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

… its mapping

Patch series "Some cleanup for page migration", v3.

This patchset does some cleanups and improvements for page migration.

This patch (of 4):

There is no need to validate the file-backed page's refcount before trying
to freeze the page's expected refcount, instead we can rely on the
folio_ref_freeze() to validate if the page has the expected refcount
before migrating its mapping.

Moreover we are always under the page lock when migrating the page
mapping, which means nowhere else can remove it from the page cache, so we
can remove the xas_load() validation under the i_pages lock.

Link: https://lkml.kernel.org/r/cover.1629447552.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/df4c129fd8e86a95dbc55f4663d77441cc0d3bd1.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

This reverts commit 2107804.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

This reverts commit bc9bbb8.

This reverts commit 42a20f8.

…che.git

…cxl/cxl.git

…/shuah/linux-kselftest.git

# Conflicts:
#	tools/testing/kunit/kunit.py

…git/srini/nvmem.git

…joel/fsi.git

…/git/johan/gnss.git

…rnel/git/gustavoars/linux.git

…rnel/git/kees/linux.git

…/kernel/git/kees/linux.git

…rnel/git/brgl/linux.git

…ux/kernel/git/nvdimm/nvdimm.git

…git/abelloni/linux.git

…git/livepatching/livepatching

…git/ebiederm/user-namespace.git

…git/pinctrl/samsung.git