linux-stable.git/mm/rmap.c, branch v5.16

Merge branch 'akpm' (patches from Andrew)

2021-11-06T21:08:17+00:00

Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton : (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...

mm/rmap.c: avoid double faults migrating device private pages

2021-11-06T20:30:43+00:00

During migration special page table entries are installed for each page
being migrated.  These entries store the pfn and associated permissions
of ptes mapping the page being migarted.

Device-private pages use special swap pte entries to distinguish
read-only vs.  writeable pages which the migration code checks when
creating migration entries.  Normally this follows a fast path in
migrate_vma_collect_pmd() which correctly copies the permissions of
device-private pages over to migration entries when migrating pages back
to the CPU.

However the slow-path falls back to using try_to_migrate() which
unconditionally creates read-only migration entries for device-private
pages.  This leads to unnecessary double faults on the CPU as the new
pages are always mapped read-only even when they could be mapped
writeable.  Fix this by correctly copying device-private permissions in
try_to_migrate_one().

Link: https://lkml.kernel.org/r/20211018045247.3128058-1-apopple@nvidia.com
Signed-off-by: Alistair Popple 
Reported-by: Ralph Campbell 
Reviewed-by: John Hubbard 
Cc: Jerome Glisse 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/rmap: Add folio_mkclean()

2021-10-18T11:49:39+00:00

Transform page_mkclean() into folio_mkclean() and add a page_mkclean()
wrapper around folio_mkclean().

folio_mkclean is 15 bytes smaller than page_mkclean, but the kernel
is enlarged by 33 bytes due to inlining page_folio() into each caller.
This will go away once the callers are converted to use folio_mkclean().

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: David Howells 
Acked-by: Vlastimil Babka

mm/memcg: Add folio_lruvec_lock() and similar functions

2021-09-27T13:27:31+00:00

These are the folio equivalents of lock_page_lruvec() and similar
functions.  Also convert lruvec_memcg_debug() to take a folio.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: David Howells 
Acked-by: Vlastimil Babka

Merge branch 'akpm' (patches from Andrew)

2021-09-08T19:55:35+00:00

Merge more updates from Andrew Morton:
 "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f.

  Subsystems affected by this patch series: mm (memory-hotplug, rmap,
  ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
  alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
  checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
  selftests, ipc, and scripts"

* emailed patches from Andrew Morton : (94 commits)
  scripts: check_extable: fix typo in user error message
  mm/workingset: correct kernel-doc notations
  ipc: replace costly bailout check in sysvipc_find_ipc()
  selftests/memfd: remove unused variable
  Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
  configs: remove the obsolete CONFIG_INPUT_POLLDEV
  prctl: allow to setup brk for et_dyn executables
  pid: cleanup the stale comment mentioning pidmap_init().
  kernel/fork.c: unexport get_{mm,task}_exe_file
  coredump: fix memleak in dump_vma_snapshot()
  fs/coredump.c: log if a core dump is aborted due to changed file permissions
  nilfs2: use refcount_dec_and_lock() to fix potential UAF
  nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
  nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
  nilfs2: fix NULL pointer in nilfs_##name##_attr_release
  nilfs2: fix memory leak in nilfs_sysfs_create_device_group
  trap: cleanup trap_init()
  init: move usermodehelper_enable() to populate_rootfs()
  ...

mm: remove redundant compound_head() calling

2021-09-08T18:50:23+00:00

There is a READ_ONCE() in the macro of compound_head(), which will prevent
compiler from optimizing the code when there are more than once calling of
it in a function.  Remove the redundant calling of compound_head() from
page_to_index() and page_add_file_rmap() for better code generation.

Link: https://lkml.kernel.org/r/20210811101431.83940-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song 
Reviewed-by: David Howells 
Cc: Matthew Wilcox (Oracle) 
Cc: William Kucharski 
Cc: Kirill A. Shutemov 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2021-08-30T17:24:50+00:00

Pull fs hole punching vs cache filling race fixes from Jan Kara:
 "Fix races leading to possible data corruption or stale data exposure
  in multiple filesystems when hole punching races with operations such
  as readahead.

  This is the series I was sending for the last merge window but with
  your objection fixed - now filemap_fault() has been modified to take
  invalidate_lock only when we need to create new page in the page cache
  and / or bring it uptodate"

* tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  filesystems/locking: fix Malformed table warning
  cifs: Fix race between hole punch and page fault
  ceph: Fix race between hole punch and page fault
  fuse: Convert to using invalidate_lock
  f2fs: Convert to using invalidate_lock
  zonefs: Convert to using invalidate_lock
  xfs: Convert double locking of MMAPLOCK to use VFS helpers
  xfs: Convert to use invalidate_lock
  xfs: Refactor xfs_isilocked()
  ext2: Convert to using invalidate_lock
  ext4: Convert to use mapping->invalidate_lock
  mm: Add functions to lock invalidate_lock for two mappings
  mm: Protect operations adding pages to page cache with invalidate_lock
  documentation: Sync file_operations members with reality
  mm: Fix comments mentioning i_mutex

mm: Protect operations adding pages to page cache with invalidate_lock

2021-07-13T11:14:27+00:00

Currently, serializing operations such as page fault, read, or readahead
against hole punching is rather difficult. The basic race scheme is
like:

fallocate(FALLOC_FL_PUNCH_HOLE)			read / fault / ..
  truncate_inode_pages_range()
						  
  

Now the problem is in this way read / page fault / readahead can
instantiate pages in page cache with potentially stale data (if blocks
get quickly reused). Avoiding this race is not simple - page locks do
not work because we want to make sure there are *no* pages in given
range. inode->i_rwsem does not work because page fault happens under
mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes
the performance for mixed read-write workloads suffer.

So create a new rw_semaphore in the address_space - invalidate_lock -
that protects adding of pages to page cache for page faults / reads /
readahead.

Reviewed-by: Darrick J. Wong 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jan Kara

mm/rmap: fix munlocking Anon THP with mlocked ptes

2021-07-12T18:30:56+00:00

Many thanks to Kirill for reminding that PageDoubleMap cannot be relied on
to warn of pte mappings in the Anon THP case; and a scan of subpages does
not seem appropriate here.  Note how follow_trans_huge_pmd() does not even
mark an Anon THP as mlocked when compound_mapcount != 1: multiple mlocking
of Anon THP is avoided, so simply return from page_mlock() in this case.

Link: https://lore.kernel.org/lkml/cfa154c-d595-406-eb7d-eb9df730f944@google.com/
Fixes: d9770fcc1c0c ("mm/rmap: fix old bug: munlocking THP missed other mlocks")
Reported-by: Kirill A. Shutemov 
Signed-off-by: Hugh Dickins 
Acked-by: Kirill A. Shutemov 
Cc: Andrew Morton 
Cc: Alistair Popple 
Cc: Jason Gunthorpe 
Cc: Ralph Campbell 
Cc: Christoph Hellwig 
Cc: Yang Shi 
Cc: Shakeel Butt 
Signed-off-by: Linus Torvalds

mm: Fix comments mentioning i_mutex

2021-07-12T16:31:16+00:00

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong 
Acked-by: Hugh Dickins 
Signed-off-by: Jan Kara