Commit Graph

537 Commits

Author SHA1 Message Date
Hugh Dickins af53d3e9e0 mm: swapoff: shmem_unuse() stop eviction without igrab()
The igrab() in shmem_unuse() looks good, but we forgot that it gives no
protection against concurrent unmounting: a point made by Konstantin
Khlebnikov eight years ago, and then fixed in 2.6.39 by 778dd893ae
("tmpfs: fix race between umount and swapoff").  The current 5.1-rc
swapoff is liable to hit "VFS: Busy inodes after unmount of tmpfs.
Self-destruct in 5 seconds.  Have a nice day..." followed by GPF.

Once again, give up on using igrab(); but don't go back to making such
heavy-handed use of shmem_swaplist_mutex as last time: that would spoil
the new design, and I expect could deadlock inside shmem_swapin_page().

Instead, shmem_unuse() just raise a "stop_eviction" count in the shmem-
specific inode, and shmem_evict_inode() wait for that to go down to 0.
Call it "stop_eviction" rather than "swapoff_busy" because it can be put
to use for others later (huge tmpfs patches expect to use it).

That simplifies shmem_unuse(), protecting it from both unlink and
unmount; and in practice lets it locate all the swap in its first try.
But do not rely on that: there's still a theoretical case, when
shmem_writepage() might have been preempted after its get_swap_page(),
before making the swap entry visible to swapoff.

[hughd@google.com: remove incorrect list_del()]
  Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1904091133570.1898@eggly.anvils
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1904081259400.1523@eggly.anvils
Fixes: b56a2d8af9 ("mm: rid swapoff of quadratic complexity")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vineeth Pillai <vpillai@digitalocean.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-19 09:46:04 -07:00
Hugh Dickins 8703954654 mm: swapoff: shmem_find_swap_entries() filter out other types
Swapfile "type" was passed all the way down to shmem_unuse_inode(), but
then forgotten from shmem_find_swap_entries(): with the result that
removing one swapfile would try to free up all the swap from shmem - no
problem when only one swapfile anyway, but counter-productive when more,
causing swapoff to be unnecessarily OOM-killed when it should succeed.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1904081254470.1523@eggly.anvils
Fixes: b56a2d8af9 ("mm: rid swapoff of quadratic complexity")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>
Cc: Vineeth Pillai <vpillai@digitalocean.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-19 09:46:04 -07:00
Joel Fernandes (Google) ab3948f58f mm/memfd: add an F_SEAL_FUTURE_WRITE seal to memfd
Android uses ashmem for sharing memory regions.  We are looking forward
to migrating all usecases of ashmem to memfd so that we can possibly
remove the ashmem driver in the future from staging while also
benefiting from using memfd and contributing to it.  Note staging
drivers are also not ABI and generally can be removed at anytime.

One of the main usecases Android has is the ability to create a region
and mmap it as writeable, then add protection against making any
"future" writes while keeping the existing already mmap'ed
writeable-region active.  This allows us to implement a usecase where
receivers of the shared memory buffer can get a read-only view, while
the sender continues to write to the buffer.  See CursorWindow
documentation in Android for more details:

  https://developer.android.com/reference/android/database/CursorWindow

This usecase cannot be implemented with the existing F_SEAL_WRITE seal.
To support the usecase, this patch adds a new F_SEAL_FUTURE_WRITE seal
which prevents any future mmap and write syscalls from succeeding while
keeping the existing mmap active.

A better way to do F_SEAL_FUTURE_WRITE seal was discussed [1] last week
where we don't need to modify core VFS structures to get the same
behavior of the seal.  This solves several side-effects pointed by Andy.
self-tests are provided in later patch to verify the expected semantics.

[1] https://lore.kernel.org/lkml/20181111173650.GA256781@google.com/

Thanks a lot to Andy for suggestions to improve code.

Link: http://lkml.kernel.org/r/20190112203816.85534-2-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Marc-Andr Lureau <marcandre.lureau@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:19 -08:00
Vineeth Remanan Pillai b56a2d8af9 mm: rid swapoff of quadratic complexity
This patch was initially posted by Kelley Nielsen.  Reposting the patch
with all review comments addressed and with minor modifications and
optimizations.  Also, folding in the fixes offered by Hugh Dickins and
Huang Ying.  Tests were rerun and commit message updated with new
results.

try_to_unuse() is of quadratic complexity, with a lot of wasted effort.
It unuses swap entries one by one, potentially iterating over all the
page tables for all the processes in the system for each one.

This new proposed implementation of try_to_unuse simplifies its
complexity to linear.  It iterates over the system's mms once, unusing
all the affected entries as it walks each set of page tables.  It also
makes similar changes to shmem_unuse.

Improvement

swapoff was called on a swap partition containing about 6G of data, in a
VM(8cpu, 16G RAM), and calls to unuse_pte_range() were counted.

Present implementation....about 1200M calls(8min, avg 80% cpu util).
Prototype.................about  9.0K calls(3min, avg 5% cpu util).

Details

In shmem_unuse(), iterate over the shmem_swaplist and, for each
shmem_inode_info that contains a swap entry, pass it to
shmem_unuse_inode(), along with the swap type.  In shmem_unuse_inode(),
iterate over its associated xarray, and store the index and value of
each swap entry in an array for passing to shmem_swapin_page() outside
of the RCU critical section.

In try_to_unuse(), instead of iterating over the entries in the type and
unusing them one by one, perhaps walking all the page tables for all the
processes for each one, iterate over the mmlist, making one pass.  Pass
each mm to unuse_mm() to begin its page table walk, and during the walk,
unuse all the ptes that have backing store in the swap type received by
try_to_unuse().  After the walk, check the type for orphaned swap
entries with find_next_to_unuse(), and remove them from the swap cache.
If find_next_to_unuse() starts over at the beginning of the type, repeat
the check of the shmem_swaplist and the walk a maximum of three times.

Change unuse_mm() and the intervening walk functions down to
unuse_pte_range() to take the type as a parameter, and to iterate over
their entire range, calling the next function down on every iteration.
In unuse_pte_range(), make a swap entry from each pte in the range using
the passed in type.  If it has backing store in the type, call
swapin_readahead() to retrieve the page and pass it to unuse_pte().

Pass the count of pages_to_unuse down the page table walks in
try_to_unuse(), and return from the walk when the desired number of
pages has been swapped back in.

Link: http://lkml.kernel.org/r/20190114153129.4852-2-vpillai@digitalocean.com
Signed-off-by: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Signed-off-by: Kelley Nielsen <kelleynnn@gmail.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:18 -08:00
Vineeth Remanan Pillai c5bf121e43 mm: refactor swap-in logic out of shmem_getpage_gfp
swapin logic can be reused independently without rest of the logic in
shmem_getpage_gfp.  So lets refactor it out as an independent function.

Link: http://lkml.kernel.org/r/20190114153129.4852-1-vpillai@digitalocean.com
Signed-off-by: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kelley Nielsen <kelleynnn@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:18 -08:00
Darrick J. Wong 29b00e6099 tmpfs: fix uninitialized return value in shmem_link
When we made the shmem_reserve_inode call in shmem_link conditional, we
forgot to update the declaration for ret so that it always has a known
value.  Dan Carpenter pointed out this deficiency in the original patch.

Fixes: 1062af920c ("tmpfs: fix link accounting when a tmpfile is linked in")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matej Kupljen <matej.kupljen@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-25 11:49:22 -08:00
Darrick J. Wong 1062af920c tmpfs: fix link accounting when a tmpfile is linked in
tmpfs has a peculiarity of accounting hard links as if they were
separate inodes: so that when the number of inodes is limited, as it is
by default, a user cannot soak up an unlimited amount of unreclaimable
dcache memory just by repeatedly linking a file.

But when v3.11 added O_TMPFILE, and the ability to use linkat() on the
fd, we missed accommodating this new case in tmpfs: "df -i" shows that
an extra "inode" remains accounted after the file is unlinked and the fd
closed and the actual inode evicted.  If a user repeatedly links
tmpfiles into a tmpfs, the limit will be hit (ENOSPC) even after they
are deleted.

Just skip the extra reservation from shmem_link() in this case: there's
a sense in which this first link of a tmpfile is then cheaper than a
hard link of another file, but the accounting works out, and there's
still good limiting, so no need to do anything more complicated.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1902182134370.7035@eggly.anvils
Fixes: f4e0c30c19 ("allow the temp files created by open() to be linked to")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Matej Kupljen <matej.kupljen@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-21 09:01:00 -08:00
Arun KS ca79b0c211 mm: convert totalram_pages and totalhigh_pages variables to atomic
totalram_pages and totalhigh_pages are made static inline function.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:47 -08:00
Arun KS 3d6357de8a mm: reference totalram_pages and managed_pages once per function
Patch series "mm: convert totalram_pages, totalhigh_pages and managed
pages to atomic", v5.

This series converts totalram_pages, totalhigh_pages and
zone->managed_pages to atomic variables.

totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better
to remove the lock and convert variables to atomic.  With the change,
preventing poteintial store-to-read tearing comes as a bonus.

This patch (of 4):

This is in preparation to a later patch which converts totalram_pages and
zone->managed_pages to atomic variables.  Please note that re-reading the
value might lead to a different value and as such it could lead to
unexpected behavior.  There are no known bugs as a result of the current
code but it is better to prevent from them in principle.

Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:47 -08:00
Linus Torvalds 4971f090aa drm pull request for 4.21-rc1
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Merge tag 'drm-next-2018-12-14' of git://anongit.freedesktop.org/drm/drm

Pull drm updates from Dave Airlie:
 "Core:
   - shared fencing staging removal
   - drop transactional atomic helpers and move helpers to new location
   - DP/MST atomic cleanup
   - Leasing cleanups and drop EXPORT_SYMBOL
   - Convert drivers to atomic helpers and generic fbdev.
   - removed deprecated obj_ref/unref in favour of get/put
   - Improve dumb callback documentation
   - MODESET_LOCK_BEGIN/END helpers

  panels:
   - CDTech panels, Banana Pi Panel, DLC1010GIG,
   - Olimex LCD-O-LinuXino, Samsung S6D16D0, Truly NT35597 WQXGA,
   - Himax HX8357D, simulated RTSM AEMv8.
   - GPD Win2 panel
   - AUO G101EVN010

  vgem:
   - render node support

  ttm:
   - move global init out of drivers
   - fix LRU handling for ghost objects
   - Support for simultaneous submissions to multiple engines

  scheduler:
   - timeout/fault handling changes to help GPU recovery
   - helpers for hw with preemption support

  i915:
   - Scaler/Watermark fixes
   - DP MST + powerwell fixes
   - PSR fixes
   - Break long get/put shmemfs pages
   - Icelake fixes
   - Icelake DSI video mode enablement
   - Engine workaround improvements

  amdgpu:
   - freesync support
   - GPU reset enabled on CI, VI, SOC15 dGPUs
   - ABM support in DC
   - KFD support for vega12/polaris12
   - SDMA paging queue on vega
   - More amdkfd code sharing
   - DCC scanout on GFX9
   - DC kerneldoc
   - Updated SMU firmware for GFX8 chips
   - XGMI PSP + hive reset support
   - GPU reset
   - DC trace support
   - Powerplay updates for newer Polaris
   - Cursor plane update fast path
   - kfd dma-buf support

  virtio-gpu:
   - add EDID support

  vmwgfx:
   - pageflip with damage support

  nouveau:
   - Initial Turing TU104/TU106 modesetting support

  msm:
   - a2xx gpu support for apq8060 and imx5
   - a2xx gpummu support
   - mdp4 display support for apq8060
   - DPU fixes and cleanups
   - enhanced profiling support
   - debug object naming interface
   - get_iova/page pinning decoupling

  tegra:
   - Tegra194 host1x, VIC and display support enabled
   - Audio over HDMI for Tegra186 and Tegra194

  exynos:
   - DMA/IOMMU refactoring
   - plane alpha + blend mode support
   - Color format fixes for mixer driver

  rcar-du:
   - R8A7744 and R8A77470 support
   - R8A77965 LVDS support

  imx:
   - fbdev emulation fix
   - multi-tiled scalling fixes
   - SPDX identifiers

  rockchip
   - dw_hdmi support
   - dw-mipi-dsi + dual dsi support
   - mailbox read size fix

  qxl:
   - fix cursor pinning

  vc4:
   - YUV support (scaling + cursor)

  v3d:
   - enable TFU (Texture Formatting Unit)

  mali-dp:
   - add support for linear tiled formats

  sun4i:
   - Display Engine 3 support
   - H6 DE3 mixer 0 support
   - H6 display engine support
   - dw-hdmi support
   - H6 HDMI phy support
   - implicit fence waiting
   - BGRX8888 support

  meson:
   - Overlay plane support
   - implicit fence waiting
   - HDMI 1.4 4k modes

  bridge:
   - i2c fixes for sii902x"

* tag 'drm-next-2018-12-14' of git://anongit.freedesktop.org/drm/drm: (1403 commits)
  drm/amd/display: Add fast path for cursor plane updates
  drm/amdgpu: Enable GPU recovery by default for CI
  drm/amd/display: Fix duplicating scaling/underscan connector state
  drm/amd/display: Fix unintialized max_bpc state values
  Revert "drm/amd/display: Set RMX_ASPECT as default"
  drm/amdgpu: Fix stub function name
  drm/msm/dpu: Fix clock issue after bind failure
  drm/msm/dpu: Clean up dpu_media_info.h static inline functions
  drm/msm/dpu: Further cleanups for static inline functions
  drm/msm/dpu: Cleanup the debugfs functions
  drm/msm/dpu: Remove dpu_irq and unused functions
  drm/msm: Make irq_postinstall optional
  drm/msm/dpu: Cleanup callers of dpu_hw_blk_init
  drm/msm/dpu: Remove unused functions
  drm/msm/dpu: Remove dpu_crtc_is_enabled()
  drm/msm/dpu: Remove dpu_crtc_get_mixer_height
  drm/msm/dpu: Remove dpu_dbg
  drm/msm: dpu: Remove crtc_lock
  drm/msm: dpu: Remove vblank_requested flag from dpu_crtc
  drm/msm: dpu: Separate crtc assignment from vblank enable
  ...
2018-12-25 11:48:26 -08:00
Linus Torvalds 880b9df1bf XArray updates for 4.20-rc7
Two bugfixes, each with test-suite updates, two improvements to the
 test-suite without associated bugs, and one patch adding a missing API.
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Merge tag 'xarray-4.20-rc7' of git://git.infradead.org/users/willy/linux-dax

Pull XArray fixes from Matthew Wilcox:
 "Two bugfixes, each with test-suite updates, two improvements to the
  test-suite without associated bugs, and one patch adding a missing
  API"

* tag 'xarray-4.20-rc7' of git://git.infradead.org/users/willy/linux-dax:
  XArray: Fix xa_alloc when id exceeds max
  XArray tests: Check iterating over multiorder entries
  XArray tests: Handle larger indices more elegantly
  XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh
  radix tree: Don't return retry entries from lookup
2018-12-13 16:35:58 -08:00
David Rientjes 356ff8a9a7 Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"
This reverts commit 89c83fb539.

This should have been done as part of 2f0799a0ff ("mm, thp: restore
node-local hugepage allocations").  The movement of the thp allocation
policy from alloc_pages_vma() to alloc_hugepage_direct_gfpmask() was
intended to only set __GFP_THISNODE for mempolicies that are not
MPOL_BIND whereas the revert could set this regardless of mempolicy.

While the check for MPOL_BIND between alloc_hugepage_direct_gfpmask()
and alloc_pages_vma() was racy, that has since been removed since the
revert.  What is left is the possibility to use __GFP_THISNODE in
policy_node() when it is unexpected because the special handling for
hugepages in alloc_pages_vma()  was removed as part of the consolidation.

Secondly, prior to 89c83fb539, alloc_pages_vma() implemented a somewhat
different policy for hugepage allocations, which were allocated through
alloc_hugepage_vma().  For hugepage allocations, if the allocating
process's node is in the set of allowed nodes, allocate with
__GFP_THISNODE for that node (for MPOL_PREFERRED, use that node with
__GFP_THISNODE instead).  This was changed for shmem_alloc_hugepage() to
allow fallback to other nodes in 89c83fb539 as it did for new_page() in
mm/mempolicy.c which is functionally different behavior and removes the
requirement to only allocate hugepages locally.

So this commit does a full revert of 89c83fb539 instead of the partial
revert that was done in 2f0799a0ff.  The result is the same thp
allocation policy for 4.20 that was in 4.19.

Fixes: 89c83fb539 ("mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask")
Fixes: 2f0799a0ff ("mm, thp: restore node-local hugepage allocations")
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-08 10:26:20 -08:00
Matthew Wilcox 55f3f7eab7 XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh
These convenience wrappers match the other _irq and _bh wrappers we
already have.  It turns out I'd already open-coded xa_cmpxchg_irq()
in the shmem code, so convert that.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-12-06 08:26:17 -05:00
Hugh Dickins aaa52e3400 mm/khugepaged: fix crashes due to misaccounted holes
Huge tmpfs testing on a shortish file mapped into a pmd-rounded extent
hit shmem_evict_inode()'s WARN_ON(inode->i_blocks) followed by
clear_inode()'s BUG_ON(inode->i_data.nrpages) when the file was later
closed and unlinked.

khugepaged's collapse_shmem() was forgetting to update mapping->nrpages
on the rollback path, after it had added but then needs to undo some
holes.

There is indeed an irritating asymmetry between shmem_charge(), whose
callers want it to increment nrpages after successfully accounting
blocks, and shmem_uncharge(), when __delete_from_page_cache() already
decremented nrpages itself: oh well, just add a comment on that to them
both.

And shmem_recalc_inode() is supposed to be called when the accounting is
expected to be in balance (so it can deduce from imbalance that reclaim
discarded some pages): so change shmem_charge() to update nrpages
earlier (though it's rare for the difference to matter at all).

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261523450.2275@eggly.anvils
Fixes: 800d8c63b2 ("shmem: add huge pages support")
Fixes: f3f0e1d215 ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30 14:56:15 -08:00
Andrea Arcangeli dcf7fe9d89 userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set
Set the page dirty if VM_WRITE is not set because in such case the pte
won't be marked dirty and the page would be reclaimed without writepage
(i.e.  swapout in the shmem case).

This was found by source review.  Most apps (certainly including QEMU)
only use UFFDIO_COPY on PROT_READ|PROT_WRITE mappings or the app can't
modify the memory in the first place.  This is for correctness and it
could help the non cooperative use case to avoid unexpected data loss.

Link: http://lkml.kernel.org/r/20181126173452.26955-6-aarcange@redhat.com
Reviewed-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Fixes: 4c27fe4c4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30 14:56:14 -08:00
Andrea Arcangeli e2a50c1f64 userfaultfd: shmem: add i_size checks
With MAP_SHARED: recheck the i_size after taking the PT lock, to
serialize against truncate with the PT lock.  Delete the page from the
pagecache if the i_size_read check fails.

With MAP_PRIVATE: check the i_size after the PT lock before mapping
anonymous memory or zeropages into the MAP_PRIVATE shmem mapping.

A mostly irrelevant cleanup: like we do the delete_from_page_cache()
pagecache removal after dropping the PT lock, the PT lock is a spinlock
so drop it before the sleepable page lock.

Link: http://lkml.kernel.org/r/20181126173452.26955-5-aarcange@redhat.com
Fixes: 4c27fe4c4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30 14:56:14 -08:00
Andrea Arcangeli 9e368259ad userfaultfd: use ENOENT instead of EFAULT if the atomic copy user fails
Patch series "userfaultfd shmem updates".

Jann found two bugs in the userfaultfd shmem MAP_SHARED backend: the
lack of the VM_MAYWRITE check and the lack of i_size checks.

Then looking into the above we also fixed the MAP_PRIVATE case.

Hugh by source review also found a data loss source if UFFDIO_COPY is
used on shmem MAP_SHARED PROT_READ mappings (the production usages
incidentally run with PROT_READ|PROT_WRITE, so the data loss couldn't
happen in those production usages like with QEMU).

The whole patchset is marked for stable.

We verified QEMU postcopy live migration with guest running on shmem
MAP_PRIVATE run as well as before after the fix of shmem MAP_PRIVATE.
Regardless if it's shmem or hugetlbfs or MAP_PRIVATE or MAP_SHARED, QEMU
unconditionally invokes a punch hole if the guest mapping is filebacked
and a MADV_DONTNEED too (needed to get rid of the MAP_PRIVATE COWs and
for the anon backend).

This patch (of 5):

We internally used EFAULT to communicate with the caller, switch to
ENOENT, so EFAULT can be used as a non internal retval.

Link: http://lkml.kernel.org/r/20181126173452.26955-2-aarcange@redhat.com
Fixes: 4c27fe4c4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: <stable@vger.kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30 14:56:14 -08:00
Yu Zhao c1cb20d437 mm: use swp_offset as key in shmem_replace_page()
We changed the key of swap cache tree from swp_entry_t.val to
swp_offset.  We need to do so in shmem_replace_page() as well.

Hugh said:
 "shmem_replace_page() has been wrong since the day I wrote it: good
  enough to work on swap "type" 0, which is all most people ever use
  (especially those few who need shmem_replace_page() at all), but
  broken once there are any non-0 swp_type bits set in the higher order
  bits"

Link: http://lkml.kernel.org/r/20181121215442.138545-1-yuzhao@google.com
Fixes: f6ab1f7f6b ("mm, swap: use offset of swap entry as key of swap cache")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30 14:56:14 -08:00
Jani Nikula 2ac5e38ea4 Merge drm/drm-next into drm-intel-next-queued
Pull in v4.20-rc3 via drm-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2018-11-20 13:14:08 +02:00
Yufen Yu 1a41364693 tmpfs: make lseek(SEEK_DATA/SEK_HOLE) return ENXIO with a negative offset
Other filesystems such as ext4, f2fs and ubifs all return ENXIO when
lseek (SEEK_DATA or SEEK_HOLE) requests a negative offset.

man 2 lseek says

:      EINVAL whence  is  not  valid.   Or: the resulting file offset would be
:             negative, or beyond the end of a seekable device.
:
:      ENXIO  whence is SEEK_DATA or SEEK_HOLE, and the file offset is  beyond
:             the end of the file.

Make tmpfs return ENXIO under these circumstances as well.  After this,
tmpfs also passes xfstests's generic/448.

[akpm@linux-foundation.org: rewrite changelog]
Link: http://lkml.kernel.org/r/1540434176-14349-1-git-send-email-yuyufen@huawei.com
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:10 -08:00
Kuo-Hsin Yang 64e3d12f76 mm, drm/i915: mark pinned shmemfs pages as unevictable
The i915 driver uses shmemfs to allocate backing storage for gem
objects. These shmemfs pages can be pinned (increased ref count) by
shmem_read_mapping_page_gfp(). When a lot of pages are pinned, vmscan
wastes a lot of time scanning these pinned pages. In some extreme case,
all pages in the inactive anon lru are pinned, and only the inactive
anon lru is scanned due to inactive_ratio, the system cannot swap and
invokes the oom-killer. Mark these pinned pages as unevictable to speed
up vmscan.

Export pagevec API check_move_unevictable_pages().

This patch was inspired by Chris Wilson's change [1].

[1]: https://patchwork.kernel.org/patch/9768741/

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Kuo-Hsin Yang <vovoy@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com> # mm part
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20181106132324.17390-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
2018-11-07 15:28:32 +00:00
Michal Hocko 89c83fb539 mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask
THP allocation mode is quite complex and it depends on the defrag mode.
This complexity is hidden in alloc_hugepage_direct_gfpmask from a large
part currently. The NUMA special casing (namely __GFP_THISNODE) is
however independent and placed in alloc_pages_vma currently. This both
adds an unnecessary branch to all vma based page allocation requests and
it makes the code more complex unnecessarily as well. Not to mention
that e.g. shmem THP used to do the node reclaiming unconditionally
regardless of the defrag mode until recently. This was not only
unexpected behavior but it was also hardly a good default behavior and I
strongly suspect it was just a side effect of the code sharing more than
a deliberate decision which suggests that such a layering is wrong.

Get rid of the thp special casing from alloc_pages_vma and move the
logic to alloc_hugepage_direct_gfpmask. __GFP_THISNODE is applied to the
resulting gfp mask only when the direct reclaim is not requested and
when there is no explicit numa binding to preserve the current logic.

Please note that there's also a slight difference wrt MPOL_BIND now. The
previous code would avoid using __GFP_THISNODE if the local node was
outside of policy_nodemask(). After this patch __GFP_THISNODE is avoided
for all MPOL_BIND policies. So there's a difference that if local node
is actually allowed by the bind policy's nodemask, previously
__GFP_THISNODE would be added, but now it won't be. From the behavior
POV this is still correct because the policy nodemask is used.

Link: http://lkml.kernel.org/r/20180925120326.24392-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-03 10:09:37 -07:00
Matthew Wilcox 7f4446eefe shmem: Comment fixups
Remove the last mentions of radix tree from various comments.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:41 -04:00
Matthew Wilcox 7ae3424fb4 shmem: Convert shmem_partial_swap_usage to XArray
Simpler code because the xarray takes care of things like the limit and
dereferencing the slot.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:40 -04:00
Matthew Wilcox c121d3bb71 shmem: Convert shmem_free_swap to XArray
Since we are conditionally storing NULL in the XArray, we do not need
to allocate memory and the GFP flags will be unused.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:40 -04:00
Matthew Wilcox 7b8d046fba shmem: Convert shmem_alloc_hugepage to XArray
xa_find() is a slightly easier API to use than
radix_tree_gang_lookup_slot() because it contains its own RCU locking.
This commit removes the last user of radix_tree_gang_lookup_slot()
so remove the function too.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:40 -04:00
Matthew Wilcox 552446a416 shmem: Convert shmem_add_to_page_cache to XArray
We can use xas_find_conflict() instead of radix_tree_gang_lookup_slot()
to find any conflicting entry and combine the three paths through this
function into one.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:40 -04:00
Matthew Wilcox e21a29552f shmem: Convert find_swap_entry to XArray
This is a 1:1 conversion.  The major part of this patch is converting
the test framework from userspace to kernel space and mirroring the
algorithm now used in find_swap_entry().

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:39 -04:00
Matthew Wilcox a12831bf42 shmem: Convert shmem_confirm_swap to XArray
xa_load has its own RCU locking, so we can eliminate it here.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:39 -04:00
Matthew Wilcox 62f945b6a7 shmem: Convert shmem_radix_tree_replace to XArray
Rename shmem_radix_tree_replace() to shmem_replace_entry() and
convert it to use the XArray API.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21 10:46:39 -04:00
Matthew Wilcox 3159f943aa xarray: Replace exceptional entries
Introduce xarray value entries and tagged pointers to replace radix
tree exceptional entries.  This is a slight change in encoding to allow
the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a
value entry).  It is also a change in emphasis; exceptional entries are
intimidating and different.  As the comment explains, you can choose
to store values or pointers in the xarray and they are both first-class
citizens.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
2018-09-29 22:47:49 -04:00
Joel Fernandes (Google) b45d71fb89 mm: shmem.c: Correctly annotate new inodes for lockdep
Directories and inodes don't necessarily need to be in the same lockdep
class.  For ex, hugetlbfs splits them out too to prevent false positives
in lockdep.  Annotate correctly after new inode creation.  If its a
directory inode, it will be put into a different class.

This should fix a lockdep splat reported by syzbot:

> ======================================================
> WARNING: possible circular locking dependency detected
> 4.18.0-rc8-next-20180810+ #36 Not tainted
> ------------------------------------------------------
> syz-executor900/4483 is trying to acquire lock:
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock
> include/linux/fs.h:765 [inline]
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at:
> shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>
> but task is already holding lock:
> 0000000025208078 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x630
> drivers/staging/android/ashmem.c:448
>
> which lock already depends on the new lock.
>
> -> #2 (ashmem_mutex){+.+.}:
>        __mutex_lock_common kernel/locking/mutex.c:925 [inline]
>        __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
>        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
>        ashmem_mmap+0x55/0x520 drivers/staging/android/ashmem.c:361
>        call_mmap include/linux/fs.h:1844 [inline]
>        mmap_region+0xf27/0x1c50 mm/mmap.c:1762
>        do_mmap+0xa10/0x1220 mm/mmap.c:1535
>        do_mmap_pgoff include/linux/mm.h:2298 [inline]
>        vm_mmap_pgoff+0x213/0x2c0 mm/util.c:357
>        ksys_mmap_pgoff+0x4da/0x660 mm/mmap.c:1585
>        __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
>        __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
>        __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #1 (&mm->mmap_sem){++++}:
>        __might_fault+0x155/0x1e0 mm/memory.c:4568
>        _copy_to_user+0x30/0x110 lib/usercopy.c:25
>        copy_to_user include/linux/uaccess.h:155 [inline]
>        filldir+0x1ea/0x3a0 fs/readdir.c:196
>        dir_emit_dot include/linux/fs.h:3464 [inline]
>        dir_emit_dots include/linux/fs.h:3475 [inline]
>        dcache_readdir+0x13a/0x620 fs/libfs.c:193
>        iterate_dir+0x48b/0x5d0 fs/readdir.c:51
>        __do_sys_getdents fs/readdir.c:231 [inline]
>        __se_sys_getdents fs/readdir.c:212 [inline]
>        __x64_sys_getdents+0x29f/0x510 fs/readdir.c:212
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #0 (&sb->s_type->i_mutex_key#9){++++}:
>        lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
>        down_write+0x8f/0x130 kernel/locking/rwsem.c:70
>        inode_lock include/linux/fs.h:765 [inline]
>        shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>        ashmem_shrink_scan+0x236/0x630 drivers/staging/android/ashmem.c:455
>        ashmem_ioctl+0x3ae/0x13a0 drivers/staging/android/ashmem.c:797
>        vfs_ioctl fs/ioctl.c:46 [inline]
>        file_ioctl fs/ioctl.c:501 [inline]
>        do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
>        ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
>        __do_sys_ioctl fs/ioctl.c:709 [inline]
>        __se_sys_ioctl fs/ioctl.c:707 [inline]
>        __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> other info that might help us debug this:
>
> Chain exists of:
>   &sb->s_type->i_mutex_key#9 --> &mm->mmap_sem --> ashmem_mutex
>
>  Possible unsafe locking scenario:
>
>        CPU0                    CPU1
>        ----                    ----
>   lock(ashmem_mutex);
>                                lock(&mm->mmap_sem);
>                                lock(ashmem_mutex);
>   lock(&sb->s_type->i_mutex_key#9);
>
>  *** DEADLOCK ***
>
> 1 lock held by syz-executor900/4483:
>  #0: 0000000025208078 (ashmem_mutex){+.+.}, at:
> ashmem_shrink_scan+0xb4/0x630 drivers/staging/android/ashmem.c:448

Link: http://lkml.kernel.org/r/20180821231835.166639-1-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Suggested-by: NeilBrown <neilb@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-20 22:01:11 +02:00
Souptick Joarder 2b74030354 mm: Change return type int to vm_fault_t for fault handlers
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

The aim is to change the return type of finish_fault() and
handle_mm_fault() to vm_fault_t type.  As part of that clean up return
type of all other recursively called functions have been changed to
vm_fault_t type.

The places from where handle_mm_fault() is getting invoked will be
change to vm_fault_t type but in a separate patch.

vmf_error() is the newly introduce inline function in 4.17-rc6.

[akpm@linux-foundation.org: don't shadow outer local `ret' in __do_huge_pmd_anonymous_page()]
Link: http://lkml.kernel.org/r/20180604171727.GA20279@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:44 -07:00
Andrew Morton a670468f5e mm: zero out the vma in vma_init()
Rather than in vm_area_alloc().  To ensure that the various oddball
stack-based vmas are in a good state.  Some of the callers were zeroing
them out, others were not.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Arnd Bergmann 46c9a946d7 shmem: use monotonic time for i_generation
get_seconds() is deprecated because it will lead to a 32-bit overflow in
2038 or 2106.  We don't need the i_generation to be strictly monotonic
anyway, and other file systems like ext4 and xfs just use prandom_u32(),
so let's use the same one here.

If this is considered too slow, we could also use ktime_get_seconds() or
ktime_get_real_seconds() to keep the previous behavior.  Both of these
return a time64_t and are not deprecated, but only return a unique value
once per second, and are predictable.

Link: http://lkml.kernel.org/r/20180620082556.581543-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
Linus Torvalds 73ba2fb33c for-4.19/block-20180812
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Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "First pull request for this merge window, there will also be a
  followup request with some stragglers.

  This pull request contains:

   - Fix for a thundering heard issue in the wbt block code (Anchal
     Agarwal)

   - A few NVMe pull requests:
      * Improved tracepoints (Keith)
      * Larger inline data support for RDMA (Steve Wise)
      * RDMA setup/teardown fixes (Sagi)
      * Effects log suppor for NVMe target (Chaitanya Kulkarni)
      * Buffered IO suppor for NVMe target (Chaitanya Kulkarni)
      * TP4004 (ANA) support (Christoph)
      * Various NVMe fixes

   - Block io-latency controller support. Much needed support for
     properly containing block devices. (Josef)

   - Series improving how we handle sense information on the stack
     (Kees)

   - Lightnvm fixes and updates/improvements (Mathias/Javier et al)

   - Zoned device support for null_blk (Matias)

   - AIX partition fixes (Mauricio Faria de Oliveira)

   - DIF checksum code made generic (Max Gurtovoy)

   - Add support for discard in iostats (Michael Callahan / Tejun)

   - Set of updates for BFQ (Paolo)

   - Removal of async write support for bsg (Christoph)

   - Bio page dirtying and clone fixups (Christoph)

   - Set of bcache fix/changes (via Coly)

   - Series improving blk-mq queue setup/teardown speed (Ming)

   - Series improving merging performance on blk-mq (Ming)

   - Lots of other fixes and cleanups from a slew of folks"

* tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits)
  blkcg: Make blkg_root_lookup() work for queues in bypass mode
  bcache: fix error setting writeback_rate through sysfs interface
  null_blk: add lock drop/acquire annotation
  Blk-throttle: reduce tail io latency when iops limit is enforced
  block: paride: pd: mark expected switch fall-throughs
  block: Ensure that a request queue is dissociated from the cgroup controller
  block: Introduce blk_exit_queue()
  blkcg: Introduce blkg_root_lookup()
  block: Remove two superfluous #include directives
  blk-mq: count the hctx as active before allocating tag
  block: bvec_nr_vecs() returns value for wrong slab
  bcache: trivial - remove tailing backslash in macro BTREE_FLAG
  bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section
  bcache: set max writeback rate when I/O request is idle
  bcache: add code comments for bset.c
  bcache: fix mistaken comments in request.c
  bcache: fix mistaken code comments in bcache.h
  bcache: add a comment in super.c
  bcache: avoid unncessary cache prefetch bch_btree_node_get()
  bcache: display rate debug parameters to 0 when writeback is not running
  ...
2018-08-14 10:23:25 -07:00
Linus Torvalds a66b4cd1e7 Merge branch 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs open-related updates from Al Viro:

 - "do we need fput() or put_filp()" rules are gone - it's always fput()
   now. We keep track of that state where it belongs - in ->f_mode.

 - int *opened mess killed - in finish_open(), in ->atomic_open()
   instances and in fs/namei.c code around do_last()/lookup_open()/atomic_open().

 - alloc_file() wrappers with saner calling conventions are introduced
   (alloc_file_clone() and alloc_file_pseudo()); callers converted, with
   much simplification.

 - while we are at it, saner calling conventions for path_init() and
   link_path_walk(), simplifying things inside fs/namei.c (both on
   open-related paths and elsewhere).

* 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  few more cleanups of link_path_walk() callers
  allow link_path_walk() to take ERR_PTR()
  make path_init() unconditionally paired with terminate_walk()
  document alloc_file() changes
  make alloc_file() static
  do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone()
  new helper: alloc_file_clone()
  create_pipe_files(): switch the first allocation to alloc_file_pseudo()
  anon_inode_getfile(): switch to alloc_file_pseudo()
  hugetlb_file_setup(): switch to alloc_file_pseudo()
  ocxlflash_getfile(): switch to alloc_file_pseudo()
  cxl_getfile(): switch to alloc_file_pseudo()
  ... and switch shmem_file_setup() to alloc_file_pseudo()
  __shmem_file_setup(): reorder allocations
  new wrapper: alloc_file_pseudo()
  kill FILE_{CREATED,OPENED}
  switch atomic_open() and lookup_open() to returning 0 in all success cases
  document ->atomic_open() changes
  ->atomic_open(): return 0 in all success cases
  get rid of 'opened' in path_openat() and the helpers downstream
  ...
2018-08-13 19:58:36 -07:00
Kirill A. Shutemov 2c4541e24c mm: use vma_init() to initialize VMAs on stack and data segments
Make sure to initialize all VMAs properly, not only those which come
from vm_area_cachep.

Link: http://lkml.kernel.org/r/20180724121139.62570-3-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Al Viro 93dec2da7b ... and switch shmem_file_setup() to alloc_file_pseudo()
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:24 -04:00
Al Viro dac2d1f6cb __shmem_file_setup(): reorder allocations
grab inode and reserve memory first.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:24 -04:00
Al Viro c9c554f214 alloc_file(): switch to passing O_... flags instead of FMODE_... mode
... so that it could set both ->f_flags and ->f_mode, without callers
having to set ->f_flags manually.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:02:57 -04:00
Tejun Heo 2cf855837b memcontrol: schedule throttling if we are congested
Memory allocations can induce swapping via kswapd or direct reclaim.  If
we are having IO done for us by kswapd and don't actually go into direct
reclaim we may never get scheduled for throttling.  So instead check to
see if our cgroup is congested, and if so schedule the throttling.
Before we return to user space the throttling stuff will only throttle
if we actually required it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09 09:07:54 -06:00
Joe Perches 0825a6f986 mm: use octal not symbolic permissions
mm/*.c files use symbolic and octal styles for permissions.

Using octal and not symbolic permissions is preferred by many as more
readable.

https://lkml.org/lkml/2016/8/2/1945

Prefer the direct use of octal for permissions.

Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.

Before:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86

Miscellanea:

o Whitespace neatening around these conversions.

Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:25 +09:00
Kirill A. Shutemov daa280753c mm/shmem.c: zero out unused vma fields in shmem_pseudo_vma_init()
shmem/tmpfs uses pseudo vma to allocate page with correct NUMA policy.

The pseudo vma doesn't have vm_page_prot set.  We are going to encode
encryption KeyID in vm_page_prot.  Having garbage there causes problems.

Zero out all unused fields in the pseudo vma.

Link: http://lkml.kernel.org/r/20180531135602.20321-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:38 -07:00
Souptick Joarder 20acce6799 mm/shmem.c: use new return type vm_fault_t
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

See commit 1c8f422059 ("mm: change return type to vm_fault_t")

vmf_error() is the newly introduce inline function in 4.17-rc6.

Link: http://lkml.kernel.org/r/20180521202410.GA17912@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:37 -07:00
Amir Goldstein 12ba780d64 tmpfs: allow decoding a file handle of an unlinked file
tmpfs uses the helper d_find_alias() to find a dentry from a decoded
inode, but d_find_alias() skips unhashed dentries, so unlinked files
cannot be decoded from a file handle.

This can be reproduced using xfstests test program open_by_handle:

  $ open_by handle -c /tmp/testdir
  $ open_by_handle -dk /tmp/testdir
  open_by_handle(/tmp/testdir/file000000) returned 116 incorrectly on an unlinked open file!

To fix this, if d_find_alias() can't find a hashed alias, call
d_find_any_alias() to return an unhashed one.

Link: http://lkml.kernel.org/r/CAOQ4uxg+qSLP0KwdW+h1tcPqOCQd+_pGZVXiePQB1TXCMBMctQ@mail.gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00
Yang Shi 89fdcd262f mm: shmem: make stat.st_blksize return huge page size if THP is on
Since tmpfs THP was supported in 4.8, hugetlbfs is not the only
filesystem with huge page support anymore.  tmpfs can use huge page via
THP when mounting by "huge=" mount option.

When applications use huge page on hugetlbfs, it just need check the
filesystem magic number, but it is not enough for tmpfs.  Make
stat.st_blksize return huge page size if it is mounted by appropriate
"huge=" option to give applications a hint to optimize the behavior with
THP.

Some applications may not do wisely with THP.  For example, QEMU may
mmap file on non huge page aligned hint address with MAP_FIXED, which
results in no pages are PMD mapped even though THP is used.  Some
applications may mmap file with non huge page aligned offset.  Both
behaviors make THP pointless.

statfs.f_bsize still returns 4KB for tmpfs since THP could be split, and
it also may fallback to 4KB page silently if there is not enough huge
page.  Furthermore, different f_bsize makes max_blocks and free_blocks
calculation harder but without too much benefit.  Returning huge page
size via stat.st_blksize sounds good enough.

Since PUD size huge page for THP has not been supported, now it just
returns HPAGE_PMD_SIZE.

Hugh said:

: Sorry, I have no enthusiasm for this patch; but do I feel strongly
: enough to override you and everyone else to NAK it?  No, I don't feel
: that strongly, maybe st_blksize isn't worth arguing over.
:
: We did look at struct stat when designing huge tmpfs, to see if there
: were any fields that should be adjusted for it; but concluded none.
: Yes, it would sometimes be nice to have a quickly accessible indicator
: for when tmpfs has been mounted huge (scanning /proc/mounts for options
: can be tiresome, agreed); but since tmpfs tries to supply huge (or not)
: pages transparently, no difference seemed right.
:
: So, because st_blksize is a not very useful field of struct stat, with
: "size" in the name, we're going to put HPAGE_PMD_SIZE in there instead
: of PAGE_SIZE, if the tmpfs was mounted with one of the huge "huge"
: options (force or always, okay; within_size or advise, not so much).
: Though HPAGE_PMD_SIZE is no more its "preferred I/O size" or "blocksize
: for file system I/O" than PAGE_SIZE was.
:
: Which we can expect to speed up some applications and disadvantage
: others, depending on how they interpret st_blksize: just like if we
: changed it in the same way on non-huge tmpfs.  (Did I actually try
: changing st_blksize early on, and find it broke something?  If so, I've
: now forgotten what, and a search through commit messages didn't find
: it; but I guess we'll find out soon enough.)
:
: If there were an mstat() syscall, returning a field "preferred
: alignment", then we could certainly agree to put HPAGE_PMD_SIZE in
: there; but in stat()'s st_blksize?  And what happens when (in future)
: mm maps this or that hard-disk filesystem's blocks with a pmd mapping -
: should that filesystem then advertise a bigger st_blksize, despite the
: same disk layout as before?  What happens with DAX?
:
: And this change is not going to help the QEMU suboptimality that
: brought you here (or does QEMU align mmaps according to st_blksize?).
: QEMU ought to work well with kernels without this change, and kernels
: with this change; and I hope it can easily deal with both by avoiding
: that use of MAP_FIXED which prevented the kernel's intended alignment.

[akpm@linux-foundation.org: remove unneeded `else']
Link: http://lkml.kernel.org/r/1524665633-83806-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:35 -07:00
Mike Kravetz 5d752600a8 mm: restructure memfd code
With the addition of memfd hugetlbfs support, we now have the situation
where memfd depends on TMPFS -or- HUGETLBFS.  Previously, memfd was only
supported on tmpfs, so it made sense that the code resided in shmem.c.
In the current code, memfd is only functional if TMPFS is defined.  If
HUGETLFS is defined and TMPFS is not defined, then memfd functionality
will not be available for hugetlbfs.  This does not cause BUGs, just a
lack of potentially desired functionality.

Code is restructured in the following way:
- include/linux/memfd.h is a new file containing memfd specific
  definitions previously contained in shmem_fs.h.
- mm/memfd.c is a new file containing memfd specific code previously
  contained in shmem.c.
- memfd specific code is removed from shmem_fs.h and shmem.c.
- A new config option MEMFD_CREATE is added that is defined if TMPFS
  or HUGETLBFS is defined.

No functional changes are made to the code: restructuring only.

Link: http://lkml.kernel.org/r/20180415182119.4517-4-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marc-Andr Lureau <marcandre.lureau@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:35 -07:00
Mike Kravetz c49fcfcda8 mm/shmem: update file sealing comments and file checking
In preparation for memfd code restructure, update comments, definitions
and function names dealing with file sealing to indicate that tmpfs and
hugetlbfs are the supported filesystems.  Also, change file pointer
checks in memfd_file_seals_ptr to use defined interfaces instead of
directly referencing file_operation structs.

Link: http://lkml.kernel.org/r/20180415182119.4517-3-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marc-Andr Lureau <marcandre.lureau@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:35 -07:00
Mike Kravetz 5b9c98f308 mm/shmem: add __rcu annotations and properly deref radix entry
Patch series "restructure memfd code", v4.

This patch (of 3):

In preparation for memfd code restucture, clean up sparse warnings.
Most changes required adding __rcu annotations.  The routine
find_swap_entry was modified to properly deference radix tree entries.

Link: http://lkml.kernel.org/r/20180415182119.4517-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Marc-Andr Lureau <marcandre.lureau@gmail.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:34 -07:00