[PATCH] drm/i915/userptr: Acquire the page lock around set_page_dirty()

[PATCH] drm/i915/userptr: Acquire the page lock around set_page_dirty()

[Chris Wilson]

set_page_dirty says:

	For pages with a mapping this should be done under the page lock
	for the benefit of asynchronous memory errors who prefer a
	consistent dirty state. This rule can be broken in some special
	cases, but should be better not to.

	If the mapping doesn't provide a set_page_dirty a_op, then
	just fall through and assume that it wants buffer_heads.

Under those rules, it only safe for us to use the plain set_page_dirty()
calls for shmemfs/anonymous memory. Userptr may be used with real
mappings and so needs to use the locked version (set_page_dirty_lock).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203317
Fixes: 5cc9ed4b9a7a ("drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index 16ccec7fb7da..32d208ede343 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -665,7 +665,15 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj,
 
 	for_each_sgt_page(page, sgt_iter, pages) {
 		if (obj->mm.dirty)
-			set_page_dirty(page);
+			/*
+			 * As this may not be anonymous memory (e.g. shmem)
+			 * but exist on a real mapping, we have to lock
+			 * the page in order to dirty it -- holding
+			 * the page reference is not sufficient to
+			 * prevent the inode from being truncated.
+			 * Play safe and take the lock.
+			 */
+			set_page_dirty_lock(page);
 
 		mark_page_accessed(page);
 		put_page(page);
-- 
2.20.1

✓ Fi.CI.BAT: success for drm/i915/userptr: Acquire the page lock around set_page_dirty()

[Patchwork]

== Series Details ==

Series: drm/i915/userptr: Acquire the page lock around set_page_dirty()
URL   : https://patchwork.freedesktop.org/series/63383/
State : success

== Summary ==

CI Bug Log - changes from CI_DRM_6431 -> Patchwork_13563
====================================================

Summary
-------

  **SUCCESS**

  No regressions found.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/

Known issues
------------

  Here are the changes found in Patchwork_13563 that come from known issues:

### IGT changes ###

#### Possible fixes ####

  * igt@gem_close_race@basic-process:
    - fi-icl-u3:          [DMESG-WARN][1] ([fdo#107724]) -> [PASS][2]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/fi-icl-u3/igt@gem_close_race@basic-process.html
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/fi-icl-u3/igt@gem_close_race@basic-process.html

  * igt@i915_selftest@live_hangcheck:
    - fi-icl-u3:          [INCOMPLETE][3] ([fdo#107713] / [fdo#108569]) -> [PASS][4]
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/fi-icl-u3/igt@i915_selftest@live_hangcheck.html
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/fi-icl-u3/igt@i915_selftest@live_hangcheck.html

  * igt@kms_chamelium@hdmi-hpd-fast:
    - fi-kbl-7500u:       [FAIL][5] ([fdo#109485]) -> [PASS][6]
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/fi-kbl-7500u/igt@kms_chamelium@hdmi-hpd-fast.html
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/fi-kbl-7500u/igt@kms_chamelium@hdmi-hpd-fast.html

  
  [fdo#107713]: https://bugs.freedesktop.org/show_bug.cgi?id=107713
  [fdo#107724]: https://bugs.freedesktop.org/show_bug.cgi?id=107724
  [fdo#108569]: https://bugs.freedesktop.org/show_bug.cgi?id=108569
  [fdo#109485]: https://bugs.freedesktop.org/show_bug.cgi?id=109485


Participating hosts (53 -> 46)
------------------------------

  Additional (1): fi-pnv-d510 
  Missing    (8): fi-ilk-m540 fi-hsw-4200u fi-bsw-n3050 fi-byt-squawks fi-bsw-cyan fi-icl-y fi-byt-clapper fi-bdw-samus 


Build changes
-------------

  * Linux: CI_DRM_6431 -> Patchwork_13563

  CI_DRM_6431: 9a40fb28e45261f2fc44a9b271c19faf1f071138 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_5090: c6c75e11175baeb6b984e0cc13c6fbe2863a0794 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_13563: 109e5cd074f28246bf9f146d57ccf1492d61253c @ git://anongit.freedesktop.org/gfx-ci/linux


== Kernel 32bit build ==

Warning: Kernel 32bit buildtest failed:
https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/build_32bit.log

  CALL    scripts/checksyscalls.sh
  CALL    scripts/atomic/check-atomics.sh
  CHK     include/generated/compile.h
Kernel: arch/x86/boot/bzImage is ready  (#1)
  Building modules, stage 2.
  MODPOST 112 modules
ERROR: "__udivdi3" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: "__divdi3" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
scripts/Makefile.modpost:91: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1287: recipe for target 'modules' failed
make: *** [modules] Error 2


== Linux commits ==

109e5cd074f2 drm/i915/userptr: Acquire the page lock around set_page_dirty()

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

✓ Fi.CI.IGT: success for drm/i915/userptr: Acquire the page lock around set_page_dirty()

[Patchwork]

== Series Details ==

Series: drm/i915/userptr: Acquire the page lock around set_page_dirty()
URL   : https://patchwork.freedesktop.org/series/63383/
State : success

== Summary ==

CI Bug Log - changes from CI_DRM_6431_full -> Patchwork_13563_full
====================================================

Summary
-------

  **SUCCESS**

  No regressions found.

  

Known issues
------------

  Here are the changes found in Patchwork_13563_full that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@i915_suspend@sysfs-reader:
    - shard-apl:          [PASS][1] -> [DMESG-WARN][2] ([fdo#108566]) +4 similar issues
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-apl1/igt@i915_suspend@sysfs-reader.html
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-apl4/igt@i915_suspend@sysfs-reader.html

  * igt@kms_flip@flip-vs-expired-vblank:
    - shard-glk:          [PASS][3] -> [FAIL][4] ([fdo#105363]) +2 similar issues
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-glk9/igt@kms_flip@flip-vs-expired-vblank.html
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-glk5/igt@kms_flip@flip-vs-expired-vblank.html

  * igt@kms_frontbuffer_tracking@fbc-1p-primscrn-pri-indfb-draw-pwrite:
    - shard-iclb:         [PASS][5] -> [FAIL][6] ([fdo#103167]) +3 similar issues
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-iclb5/igt@kms_frontbuffer_tracking@fbc-1p-primscrn-pri-indfb-draw-pwrite.html
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-iclb8/igt@kms_frontbuffer_tracking@fbc-1p-primscrn-pri-indfb-draw-pwrite.html

  * igt@kms_frontbuffer_tracking@fbc-suspend:
    - shard-kbl:          [PASS][7] -> [DMESG-WARN][8] ([fdo#108566]) +4 similar issues
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-kbl1/igt@kms_frontbuffer_tracking@fbc-suspend.html
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-kbl6/igt@kms_frontbuffer_tracking@fbc-suspend.html

  * igt@kms_pipe_crc_basic@nonblocking-crc-pipe-b-frame-sequence:
    - shard-skl:          [PASS][9] -> [FAIL][10] ([fdo#103191])
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl5/igt@kms_pipe_crc_basic@nonblocking-crc-pipe-b-frame-sequence.html
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl10/igt@kms_pipe_crc_basic@nonblocking-crc-pipe-b-frame-sequence.html

  * igt@kms_plane@plane-panning-bottom-right-suspend-pipe-b-planes:
    - shard-skl:          [PASS][11] -> [INCOMPLETE][12] ([fdo#104108])
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl7/igt@kms_plane@plane-panning-bottom-right-suspend-pipe-b-planes.html
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl10/igt@kms_plane@plane-panning-bottom-right-suspend-pipe-b-planes.html

  * igt@kms_plane_alpha_blend@pipe-a-constant-alpha-min:
    - shard-skl:          [PASS][13] -> [FAIL][14] ([fdo#108145])
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl2/igt@kms_plane_alpha_blend@pipe-a-constant-alpha-min.html
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl7/igt@kms_plane_alpha_blend@pipe-a-constant-alpha-min.html

  * igt@kms_plane_alpha_blend@pipe-b-coverage-7efc:
    - shard-skl:          [PASS][15] -> [FAIL][16] ([fdo#108145] / [fdo#110403])
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl4/igt@kms_plane_alpha_blend@pipe-b-coverage-7efc.html
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl1/igt@kms_plane_alpha_blend@pipe-b-coverage-7efc.html

  * igt@kms_setmode@basic:
    - shard-kbl:          [PASS][17] -> [FAIL][18] ([fdo#99912])
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-kbl3/igt@kms_setmode@basic.html
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-kbl7/igt@kms_setmode@basic.html

  * igt@perf@polling:
    - shard-skl:          [PASS][19] -> [FAIL][20] ([fdo#110728])
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl4/igt@perf@polling.html
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl3/igt@perf@polling.html

  
#### Possible fixes ####

  * igt@gem_eio@unwedge-stress:
    - shard-snb:          [FAIL][21] ([fdo#109661]) -> [PASS][22]
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-snb5/igt@gem_eio@unwedge-stress.html
   [22]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-snb7/igt@gem_eio@unwedge-stress.html

  * igt@kms_flip@flip-vs-expired-vblank-interruptible:
    - shard-skl:          [FAIL][23] ([fdo#105363]) -> [PASS][24]
   [23]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl10/igt@kms_flip@flip-vs-expired-vblank-interruptible.html
   [24]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl4/igt@kms_flip@flip-vs-expired-vblank-interruptible.html

  * igt@kms_flip@flip-vs-suspend-interruptible:
    - shard-skl:          [INCOMPLETE][25] ([fdo#109507]) -> [PASS][26]
   [25]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl3/igt@kms_flip@flip-vs-suspend-interruptible.html
   [26]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl7/igt@kms_flip@flip-vs-suspend-interruptible.html
    - shard-apl:          [DMESG-WARN][27] ([fdo#108566]) -> [PASS][28] +1 similar issue
   [27]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-apl4/igt@kms_flip@flip-vs-suspend-interruptible.html
   [28]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-apl3/igt@kms_flip@flip-vs-suspend-interruptible.html

  * igt@kms_flip@plain-flip-fb-recreate-interruptible:
    - shard-skl:          [FAIL][29] ([fdo#100368]) -> [PASS][30]
   [29]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl3/igt@kms_flip@plain-flip-fb-recreate-interruptible.html
   [30]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl6/igt@kms_flip@plain-flip-fb-recreate-interruptible.html

  * igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-cur-indfb-draw-render:
    - shard-iclb:         [FAIL][31] ([fdo#103167]) -> [PASS][32] +4 similar issues
   [31]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-iclb2/igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-cur-indfb-draw-render.html
   [32]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-iclb3/igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-cur-indfb-draw-render.html

  * igt@kms_plane@pixel-format-pipe-a-planes-source-clamping:
    - shard-iclb:         [INCOMPLETE][33] ([fdo#107713] / [fdo#110036 ]) -> [PASS][34]
   [33]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-iclb8/igt@kms_plane@pixel-format-pipe-a-planes-source-clamping.html
   [34]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-iclb1/igt@kms_plane@pixel-format-pipe-a-planes-source-clamping.html

  * igt@kms_plane_alpha_blend@pipe-c-coverage-7efc:
    - shard-skl:          [FAIL][35] ([fdo#108145] / [fdo#110403]) -> [PASS][36]
   [35]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-skl4/igt@kms_plane_alpha_blend@pipe-c-coverage-7efc.html
   [36]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-skl1/igt@kms_plane_alpha_blend@pipe-c-coverage-7efc.html

  * igt@kms_plane_lowres@pipe-a-tiling-x:
    - shard-iclb:         [FAIL][37] ([fdo#103166]) -> [PASS][38]
   [37]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-iclb6/igt@kms_plane_lowres@pipe-a-tiling-x.html
   [38]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-iclb5/igt@kms_plane_lowres@pipe-a-tiling-x.html

  * igt@kms_rotation_crc@multiplane-rotation-cropping-bottom:
    - shard-iclb:         [INCOMPLETE][39] ([fdo#107713] / [fdo#110026]) -> [PASS][40]
   [39]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-iclb7/igt@kms_rotation_crc@multiplane-rotation-cropping-bottom.html
   [40]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-iclb2/igt@kms_rotation_crc@multiplane-rotation-cropping-bottom.html

  
#### Warnings ####

  * igt@i915_pm_rpm@modeset-lpsp-stress-no-wait:
    - shard-apl:          [SKIP][41] ([fdo#109271]) -> [INCOMPLETE][42] ([fdo#103927])
   [41]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-apl1/igt@i915_pm_rpm@modeset-lpsp-stress-no-wait.html
   [42]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-apl4/igt@i915_pm_rpm@modeset-lpsp-stress-no-wait.html

  * igt@kms_content_protection@atomic:
    - shard-kbl:          [DMESG-FAIL][43] -> [FAIL][44] ([fdo#110321] / [fdo#110336])
   [43]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-kbl2/igt@kms_content_protection@atomic.html
   [44]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-kbl1/igt@kms_content_protection@atomic.html

  * igt@kms_dp_dsc@basic-dsc-enable-edp:
    - shard-iclb:         [SKIP][45] ([fdo#109349]) -> [DMESG-WARN][46] ([fdo#107724])
   [45]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_6431/shard-iclb3/igt@kms_dp_dsc@basic-dsc-enable-edp.html
   [46]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/shard-iclb2/igt@kms_dp_dsc@basic-dsc-enable-edp.html

  
  [fdo#100368]: https://bugs.freedesktop.org/show_bug.cgi?id=100368
  [fdo#103166]: https://bugs.freedesktop.org/show_bug.cgi?id=103166
  [fdo#103167]: https://bugs.freedesktop.org/show_bug.cgi?id=103167
  [fdo#103191]: https://bugs.freedesktop.org/show_bug.cgi?id=103191
  [fdo#103927]: https://bugs.freedesktop.org/show_bug.cgi?id=103927
  [fdo#104108]: https://bugs.freedesktop.org/show_bug.cgi?id=104108
  [fdo#105363]: https://bugs.freedesktop.org/show_bug.cgi?id=105363
  [fdo#107713]: https://bugs.freedesktop.org/show_bug.cgi?id=107713
  [fdo#107724]: https://bugs.freedesktop.org/show_bug.cgi?id=107724
  [fdo#108145]: https://bugs.freedesktop.org/show_bug.cgi?id=108145
  [fdo#108566]: https://bugs.freedesktop.org/show_bug.cgi?id=108566
  [fdo#109271]: https://bugs.freedesktop.org/show_bug.cgi?id=109271
  [fdo#109349]: https://bugs.freedesktop.org/show_bug.cgi?id=109349
  [fdo#109507]: https://bugs.freedesktop.org/show_bug.cgi?id=109507
  [fdo#109661]: https://bugs.freedesktop.org/show_bug.cgi?id=109661
  [fdo#110026]: https://bugs.freedesktop.org/show_bug.cgi?id=110026
  [fdo#110036 ]: https://bugs.freedesktop.org/show_bug.cgi?id=110036 
  [fdo#110321]: https://bugs.freedesktop.org/show_bug.cgi?id=110321
  [fdo#110336]: https://bugs.freedesktop.org/show_bug.cgi?id=110336
  [fdo#110403]: https://bugs.freedesktop.org/show_bug.cgi?id=110403
  [fdo#110728]: https://bugs.freedesktop.org/show_bug.cgi?id=110728
  [fdo#99912]: https://bugs.freedesktop.org/show_bug.cgi?id=99912


Participating hosts (10 -> 10)
------------------------------

  No changes in participating hosts


Build changes
-------------

  * Linux: CI_DRM_6431 -> Patchwork_13563

  CI_DRM_6431: 9a40fb28e45261f2fc44a9b271c19faf1f071138 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_5090: c6c75e11175baeb6b984e0cc13c6fbe2863a0794 @ git://anongit.freedesktop.org/xorg/app/intel-gpu-tools
  Patchwork_13563: 109e5cd074f28246bf9f146d57ccf1492d61253c @ git://anongit.freedesktop.org/gfx-ci/linux
  piglit_4509: fdc5a4ca11124ab8413c7988896eec4c97336694 @ git://anongit.freedesktop.org/piglit

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_13563/
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH] drm/i915/userptr: Acquire the page lock around set_page_dirty()

[Sasha Levin]

Hi,

[This is an automated email]

This commit has been processed because it contains a "Fixes:" tag,
fixing commit: 5cc9ed4b9a7a drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl.

The bot has tested the following trees: v5.1.16, v4.19.57, v4.14.132, v4.9.184, v4.4.184.

v5.1.16: Build OK!
v4.19.57: Build OK!
v4.14.132: Build OK!
v4.9.184: Failed to apply! Possible dependencies:
    0e70447605f4 ("drm/i915: Move common code out of i915_gpu_error.c")
    1b36595ffb35 ("drm/i915: Show RING registers through debugfs")
    275f039db56f ("drm/i915: Move user fault tracking to a separate list")
    3594a3e21f1f ("drm/i915: Remove superfluous locking around userfault_list")
    3b3f1650b1ca ("drm/i915: Allocate intel_engine_cs structure only for the enabled engines")
    7c108fd8feac ("drm/i915: Move fence cancellation to runtime suspend")
    8baa1f04b9ed ("drm/i915: Update debugfs describe_obj() to show fault-mappable")
    96d776345277 ("drm/i915: Use a radixtree for random access to the object's backing storage")
    9c870d03674f ("drm/i915: Use RPM as the barrier for controlling user mmap access")
    a4f5ea64f0a8 ("drm/i915: Refactor object page API")
    d636951ec01b ("drm/i915: Cleanup instdone collection")
    f8a7fde45610 ("drm/i915: Defer active reference until required")

v4.4.184: Failed to apply! Possible dependencies:
    09cbfeaf1a5a ("mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros")
    0a798eb92e6d ("drm/i915: Refactor duplicate object vmap functions")
    0b5372727be3 ("drm/i915/cmdparser: Use cached vmappings")
    0e749e54244e ("dax: increase granularity of dax_clear_blocks() operations")
    0eb973d31d0a ("drm/i915: Cache ringbuffer GTT VMA")
    43394c7d0d36 ("drm/i915: Extract i915_gem_obj_prepare_shmem_write()")
    4420cfd3f51c ("staging: lustre: format properly all comment blocks for LNet core")
    52db400fcd50 ("pmem, dax: clean up clear_pmem()")
    5fd88337d209 ("staging: lustre: fix all conditional comparison to zero in LNet layer")
    85d1225ec066 ("drm/i915: Introduce & use new lightweight SGL iterators")
    a188222b6ed2 ("net: Rename NETIF_F_ALL_CSUM to NETIF_F_CSUM_MASK")
    a4f5ea64f0a8 ("drm/i915: Refactor object page API")
    b2e0d1625e19 ("dax: fix lifetime of in-kernel dax mappings with dax_map_atomic()")
    b9bcd14a2b91 ("drm/i915: Extract checking for backing struct pages to a helper")
    d1a5f2b4d8a1 ("block: use DAX for partition table reads")
    def0c5f6b0cd ("drm/i915: Map the ringbuffer using WB on LLC machines")
    e10624f8c097 ("pmem: fail io-requests to known bad blocks")


NOTE: The patch will not be queued to stable trees until it is upstream.

How should we proceed with this patch?

--
Thanks,
Sasha
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Re: [Intel-gfx] [PATCH] drm/i915/userptr: Acquire the page lock around set_page_dirty()

[Tvrtko Ursulin]

On 08/07/2019 15:03, Chris Wilson wrote:
> set_page_dirty says:
> 
> 	For pages with a mapping this should be done under the page lock
> 	for the benefit of asynchronous memory errors who prefer a
> 	consistent dirty state. This rule can be broken in some special
> 	cases, but should be better not to.
> 
> 	If the mapping doesn't provide a set_page_dirty a_op, then
> 	just fall through and assume that it wants buffer_heads.
> 
> Under those rules, it only safe for us to use the plain set_page_dirty()
> calls for shmemfs/anonymous memory. Userptr may be used with real
> mappings and so needs to use the locked version (set_page_dirty_lock).
> 
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203317
> Fixes: 5cc9ed4b9a7a ("drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: stable@vger.kernel.org
> ---
>   drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> index 16ccec7fb7da..32d208ede343 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> @@ -665,7 +665,15 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj,
>   
>   	for_each_sgt_page(page, sgt_iter, pages) {
>   		if (obj->mm.dirty)
> -			set_page_dirty(page);
> +			/*
> +			 * As this may not be anonymous memory (e.g. shmem)
> +			 * but exist on a real mapping, we have to lock
> +			 * the page in order to dirty it -- holding
> +			 * the page reference is not sufficient to
> +			 * prevent the inode from being truncated.
> +			 * Play safe and take the lock.
> +			 */
> +			set_page_dirty_lock(page);
>   
>   		mark_page_accessed(page);
>   		put_page(page);
> 

Not an expert but sounds plausible.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Regards,

Tvrtko