[PATCH v2] mm: Add unmap_mapping_pages

[PATCH v2] mm: Add unmap_mapping_pages

[Matthew Wilcox]

v2:
 - Fix inverted mask in dax.c
 - Pass 'false' instead of '0' for 'only_cows'
 - nommu definition

Re: [PATCH v2] mm: Add unmap_mapping_pages

[Ross Zwisler]

On Tue, Dec 05, 2017 at 07:44:53AM -0800, Matthew Wilcox wrote:
> v2:
>  - Fix inverted mask in dax.c
>  - Pass 'false' instead of '0' for 'only_cows'
>  - nommu definition
> 
> >From ceee2e58548a5264b61000c02371956a1da3bee4 Mon Sep 17 00:00:00 2001
> From: Matthew Wilcox <mawilcox@microsoft.com>
> Date: Tue, 5 Dec 2017 00:15:54 -0500
> Subject: [PATCH] mm: Add unmap_mapping_pages
> 
> Several users of unmap_mapping_range() would much prefer to express
> their range in pages rather than bytes.  Unfortuately, on a 32-bit
> kernel, you have to remember to cast your page number to a 64-bit type
> before shifting it, and four places in the current tree didn't remember
> to do that.  That's a sign of a bad interface.
> 
> Conveniently, unmap_mapping_range() actually converts from bytes into
> pages, so hoist the guts of unmap_mapping_range() into the new function
> unmap_mapping_pages() and convert the callers which want to use pages.
> 
> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
> Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>

Looks good.  You can add:

Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

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[PATCH v3] mm: Add unmap_mapping_pages

[Matthew Wilcox]

v3:
 - Fix compilation
   (I forgot to git commit --amend)
 - Added Ross' Reviewed-by
v2:
 - Fix inverted mask in dax.c
 - Pass 'false' instead of '0' for 'only_cows'
 - nommu definition

--- 8< ---

Re: [PATCH v3] mm: Add unmap_mapping_pages

[Ross Zwisler]

On Wed, Dec 06, 2017 at 06:26:27AM -0800, Matthew Wilcox wrote:
> v3:
>  - Fix compilation
>    (I forgot to git commit --amend)
>  - Added Ross' Reviewed-by
> v2:
>  - Fix inverted mask in dax.c
>  - Pass 'false' instead of '0' for 'only_cows'
>  - nommu definition
> 
> --- 8< ---
> 
> From df142c51e111f7c386f594d5443530ea17abba5f Mon Sep 17 00:00:00 2001
> From: Matthew Wilcox <mawilcox@microsoft.com>
> Date: Tue, 5 Dec 2017 00:15:54 -0500
> Subject: [PATCH v3] mm: Add unmap_mapping_pages

Just FYI, the above scissors doesn't allow me to apply the patch using git
version 2.14.3:

  $ git am --scissors  ~/patch/out.patch
  Patch is empty.
  When you have resolved this problem, run "git am --continue".
  If you prefer to skip this patch, run "git am --skip" instead.
  To restore the original branch and stop patching, run "git am --abort".

It's mad about the second set of mail headers in the body of your mail, and
tries to separate into a second patch.

You can get around this either by a) not having the second set of headers
(From:, Date:, Subject:), or by including the extra info in a separate block
below the --- line, i.e.:

  ...
  Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
  Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
  Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
  ---
  
  v3:
   - Fix compilation
     (I forgot to git commit --amend)
   - Added Ross' Reviewed-by
  v2:
   - Fix inverted mask in dax.c
   - Pass 'false' instead of '0' for 'only_cows'
   - nommu definition
  
  ---
   fs/dax.c           | 19 ++++++-------------
   include/linux/mm.h | 26 ++++++++++++++++----------
  ...

- Ross

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Re: [PATCH v3] mm: Add unmap_mapping_pages

[Kirill A. Shutemov]

On Wed, Dec 06, 2017 at 06:26:27AM -0800, Matthew Wilcox wrote:
> v3:
>  - Fix compilation
>    (I forgot to git commit --amend)
>  - Added Ross' Reviewed-by
> v2:
>  - Fix inverted mask in dax.c
>  - Pass 'false' instead of '0' for 'only_cows'
>  - nommu definition
> 
> --- 8< ---
> 
> From df142c51e111f7c386f594d5443530ea17abba5f Mon Sep 17 00:00:00 2001
> From: Matthew Wilcox <mawilcox@microsoft.com>
> Date: Tue, 5 Dec 2017 00:15:54 -0500
> Subject: [PATCH v3] mm: Add unmap_mapping_pages
> 
> Several users of unmap_mapping_range() would prefer to express their
> range in pages rather than bytes.  Unfortuately, on a 32-bit kernel,
> you have to remember to cast your page number to a 64-bit type before
> shifting it, and four places in the current tree didn't remember to
> do that.  That's a sign of a bad interface.
> 
> Conveniently, unmap_mapping_range() actually converts from bytes into
> pages, so hoist the guts of unmap_mapping_range() into a new function
> unmap_mapping_pages() and convert the callers which want to use pages.
> 
> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
> Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

Looks good to me.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

-- 
 Kirill A. Shutemov

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Re: [PATCH v2] mm: Add unmap_mapping_pages

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 8836 bytes --]

Hi Matthew,

I love your patch! Yet something to improve:

[auto build test ERROR on mmotm/master]
[also build test ERROR on v4.15-rc2 next-20171207]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Matthew-Wilcox/mm-Add-unmap_mapping_pages/20171208-072634
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: i386-tinyconfig (attached as .config)
compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All error/warnings (new ones prefixed by >>):

   In file included from include/linux/memcontrol.h:29:0,
                    from include/linux/swap.h:9,
                    from include/linux/suspend.h:5,
                    from arch/x86/kernel/asm-offsets.c:13:
   include/linux/mm.h: In function 'unmap_shared_mapping_range':
>> include/linux/mm.h:1328:2: error: implicit declaration of function 'unmap_mapping_range'; did you mean 'unmap_shared_mapping_range'? [-Werror=implicit-function-declaration]
     unmap_mapping_range(mapping, holebegin, holelen, 0);
     ^~~~~~~~~~~~~~~~~~~
     unmap_shared_mapping_range
   include/linux/mm.h: At top level:
>> include/linux/mm.h:1347:6: warning: conflicting types for 'unmap_mapping_range'
    void unmap_mapping_range(struct address_space *mapping,
         ^~~~~~~~~~~~~~~~~~~
   include/linux/mm.h:1328:2: note: previous implicit declaration of 'unmap_mapping_range' was here
     unmap_mapping_range(mapping, holebegin, holelen, 0);
     ^~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors
   make[2]: *** [arch/x86/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [sub-make] Error 2

vim +1328 include/linux/mm.h

e6473092bd Matt Mackall                  2008-02-04  1307  
2165009bdf Dave Hansen                   2008-06-12  1308  int walk_page_range(unsigned long addr, unsigned long end,
2165009bdf Dave Hansen                   2008-06-12  1309  		struct mm_walk *walk);
900fc5f197 Naoya Horiguchi               2015-02-11  1310  int walk_page_vma(struct vm_area_struct *vma, struct mm_walk *walk);
42b7772812 Jan Beulich                   2008-07-23  1311  void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
3bf5ee9564 Hugh Dickins                  2005-04-19  1312  		unsigned long end, unsigned long floor, unsigned long ceiling);
^1da177e4c Linus Torvalds                2005-04-16  1313  int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
^1da177e4c Linus Torvalds                2005-04-16  1314  			struct vm_area_struct *vma);
0979639595 Ross Zwisler                  2017-01-10  1315  int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
a4d1a88525 Jerome Glisse                 2017-08-31  1316  			     unsigned long *start, unsigned long *end,
0979639595 Ross Zwisler                  2017-01-10  1317  			     pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp);
3b6748e2dd Johannes Weiner               2009-06-16  1318  int follow_pfn(struct vm_area_struct *vma, unsigned long address,
3b6748e2dd Johannes Weiner               2009-06-16  1319  	unsigned long *pfn);
d87fe6607c venkatesh.pallipadi@intel.com 2008-12-19  1320  int follow_phys(struct vm_area_struct *vma, unsigned long address,
d87fe6607c venkatesh.pallipadi@intel.com 2008-12-19  1321  		unsigned int flags, unsigned long *prot, resource_size_t *phys);
28b2ee20c7 Rik van Riel                  2008-07-23  1322  int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
28b2ee20c7 Rik van Riel                  2008-07-23  1323  			void *buf, int len, int write);
^1da177e4c Linus Torvalds                2005-04-16  1324  
^1da177e4c Linus Torvalds                2005-04-16  1325  static inline void unmap_shared_mapping_range(struct address_space *mapping,
^1da177e4c Linus Torvalds                2005-04-16  1326  		loff_t const holebegin, loff_t const holelen)
^1da177e4c Linus Torvalds                2005-04-16  1327  {
^1da177e4c Linus Torvalds                2005-04-16 @1328  	unmap_mapping_range(mapping, holebegin, holelen, 0);
^1da177e4c Linus Torvalds                2005-04-16  1329  }
^1da177e4c Linus Torvalds                2005-04-16  1330  
7caef26767 Kirill A. Shutemov            2013-09-12  1331  extern void truncate_pagecache(struct inode *inode, loff_t new);
2c27c65ed0 Christoph Hellwig             2010-06-04  1332  extern void truncate_setsize(struct inode *inode, loff_t newsize);
90a8020278 Jan Kara                      2014-10-01  1333  void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
623e3db9f9 Hugh Dickins                  2012-03-28  1334  void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
750b4987b0 Nick Piggin                   2009-09-16  1335  int truncate_inode_page(struct address_space *mapping, struct page *page);
2571873621 Andi Kleen                    2009-09-16  1336  int generic_error_remove_page(struct address_space *mapping, struct page *page);
83f786680a Wu Fengguang                  2009-09-16  1337  int invalidate_inode_page(struct page *page);
83f786680a Wu Fengguang                  2009-09-16  1338  
7ee1dd3fee David Howells                 2006-01-06  1339  #ifdef CONFIG_MMU
dcddffd41d Kirill A. Shutemov            2016-07-26  1340  extern int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
dcddffd41d Kirill A. Shutemov            2016-07-26  1341  		unsigned int flags);
5c723ba5b7 Peter Zijlstra                2011-07-27  1342  extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
4a9e1cda27 Dominik Dingel                2016-01-15  1343  			    unsigned long address, unsigned int fault_flags,
4a9e1cda27 Dominik Dingel                2016-01-15  1344  			    bool *unlocked);
dcd7006c23 Matthew Wilcox                2017-12-05  1345  void unmap_mapping_pages(struct address_space *mapping,
dcd7006c23 Matthew Wilcox                2017-12-05  1346  		pgoff_t start, pgoff_t nr, bool even_cows);
dcd7006c23 Matthew Wilcox                2017-12-05 @1347  void unmap_mapping_range(struct address_space *mapping,
dcd7006c23 Matthew Wilcox                2017-12-05  1348  		loff_t const holebegin, loff_t const holelen, int even_cows);
7ee1dd3fee David Howells                 2006-01-06  1349  #else
dcddffd41d Kirill A. Shutemov            2016-07-26  1350  static inline int handle_mm_fault(struct vm_area_struct *vma,
dcddffd41d Kirill A. Shutemov            2016-07-26  1351  		unsigned long address, unsigned int flags)
7ee1dd3fee David Howells                 2006-01-06  1352  {
7ee1dd3fee David Howells                 2006-01-06  1353  	/* should never happen if there's no MMU */
7ee1dd3fee David Howells                 2006-01-06  1354  	BUG();
7ee1dd3fee David Howells                 2006-01-06  1355  	return VM_FAULT_SIGBUS;
7ee1dd3fee David Howells                 2006-01-06  1356  }
5c723ba5b7 Peter Zijlstra                2011-07-27  1357  static inline int fixup_user_fault(struct task_struct *tsk,
5c723ba5b7 Peter Zijlstra                2011-07-27  1358  		struct mm_struct *mm, unsigned long address,
4a9e1cda27 Dominik Dingel                2016-01-15  1359  		unsigned int fault_flags, bool *unlocked)
5c723ba5b7 Peter Zijlstra                2011-07-27  1360  {
5c723ba5b7 Peter Zijlstra                2011-07-27  1361  	/* should never happen if there's no MMU */
5c723ba5b7 Peter Zijlstra                2011-07-27  1362  	BUG();
5c723ba5b7 Peter Zijlstra                2011-07-27  1363  	return -EFAULT;
5c723ba5b7 Peter Zijlstra                2011-07-27  1364  }
dcd7006c23 Matthew Wilcox                2017-12-05  1365  static inline void unmap_mapping_pages(struct address_space *mapping,
dcd7006c23 Matthew Wilcox                2017-12-05  1366  		pgoff_t start, pgoff_t nr, bool even_cows) { }
dcd7006c23 Matthew Wilcox                2017-12-05  1367  static inline void unmap_mapping_range(struct address_space *mapping,
dcd7006c23 Matthew Wilcox                2017-12-05  1368  		loff_t const holebegin, loff_t const holelen, int even_cows) { }
7ee1dd3fee David Howells                 2006-01-06  1369  #endif
f33ea7f404 Nick Piggin                   2005-08-03  1370  

:::::: The code at line 1328 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
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Re: [PATCH v2] mm: Add unmap_mapping_pages

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 4668 bytes --]

Hi Matthew,

I love your patch! Yet something to improve:

[auto build test ERROR on mmotm/master]
[also build test ERROR on v4.15-rc2 next-20171207]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Matthew-Wilcox/mm-Add-unmap_mapping_pages/20171208-072634
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: i386-randconfig-a0-201749 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   In file included from include/linux/memcontrol.h:29:0,
                    from include/linux/swap.h:9,
                    from include/linux/suspend.h:5,
                    from arch/x86/kernel/asm-offsets.c:13:
   include/linux/mm.h: In function 'unmap_shared_mapping_range':
>> include/linux/mm.h:1328:2: error: implicit declaration of function 'unmap_mapping_range' [-Werror=implicit-function-declaration]
     unmap_mapping_range(mapping, holebegin, holelen, 0);
     ^
   include/linux/mm.h: At top level:
   include/linux/mm.h:1347:6: warning: conflicting types for 'unmap_mapping_range'
    void unmap_mapping_range(struct address_space *mapping,
         ^
   include/linux/mm.h:1328:2: note: previous implicit declaration of 'unmap_mapping_range' was here
     unmap_mapping_range(mapping, holebegin, holelen, 0);
     ^
   cc1: some warnings being treated as errors
   make[2]: *** [arch/x86/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [sub-make] Error 2

vim +/unmap_mapping_range +1328 include/linux/mm.h

e6473092b Matt Mackall                  2008-02-04  1307  
2165009bd Dave Hansen                   2008-06-12  1308  int walk_page_range(unsigned long addr, unsigned long end,
2165009bd Dave Hansen                   2008-06-12  1309  		struct mm_walk *walk);
900fc5f19 Naoya Horiguchi               2015-02-11  1310  int walk_page_vma(struct vm_area_struct *vma, struct mm_walk *walk);
42b777281 Jan Beulich                   2008-07-23  1311  void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
3bf5ee956 Hugh Dickins                  2005-04-19  1312  		unsigned long end, unsigned long floor, unsigned long ceiling);
^1da177e4 Linus Torvalds                2005-04-16  1313  int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
^1da177e4 Linus Torvalds                2005-04-16  1314  			struct vm_area_struct *vma);
097963959 Ross Zwisler                  2017-01-10  1315  int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
a4d1a8852 Jerome Glisse                 2017-08-31  1316  			     unsigned long *start, unsigned long *end,
097963959 Ross Zwisler                  2017-01-10  1317  			     pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp);
3b6748e2d Johannes Weiner               2009-06-16  1318  int follow_pfn(struct vm_area_struct *vma, unsigned long address,
3b6748e2d Johannes Weiner               2009-06-16  1319  	unsigned long *pfn);
d87fe6607 venkatesh.pallipadi@intel.com 2008-12-19  1320  int follow_phys(struct vm_area_struct *vma, unsigned long address,
d87fe6607 venkatesh.pallipadi@intel.com 2008-12-19  1321  		unsigned int flags, unsigned long *prot, resource_size_t *phys);
28b2ee20c Rik van Riel                  2008-07-23  1322  int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
28b2ee20c Rik van Riel                  2008-07-23  1323  			void *buf, int len, int write);
^1da177e4 Linus Torvalds                2005-04-16  1324  
^1da177e4 Linus Torvalds                2005-04-16  1325  static inline void unmap_shared_mapping_range(struct address_space *mapping,
^1da177e4 Linus Torvalds                2005-04-16  1326  		loff_t const holebegin, loff_t const holelen)
^1da177e4 Linus Torvalds                2005-04-16  1327  {
^1da177e4 Linus Torvalds                2005-04-16 @1328  	unmap_mapping_range(mapping, holebegin, holelen, 0);
^1da177e4 Linus Torvalds                2005-04-16  1329  }
^1da177e4 Linus Torvalds                2005-04-16  1330  

:::::: The code at line 1328 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 29260 bytes --]

Re: [PATCH v2] mm: Add unmap_mapping_pages

[Matthew Wilcox]

On Fri, Dec 08, 2017 at 10:38:55AM +0800, kbuild test robot wrote:
> Hi Matthew,
> 
> I love your patch! Yet something to improve:

You missed v3, kbuild robot?

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Re: [PATCH v2] mm: Add unmap_mapping_pages

[Fengguang Wu]

CC Xiaolong.

On Fri, Dec 08, 2017 at 05:36:24PM -0800, Matthew Wilcox wrote:
>On Fri, Dec 08, 2017 at 10:38:55AM +0800, kbuild test robot wrote:
>> Hi Matthew,
>>
>> I love your patch! Yet something to improve:
>
>You missed v3, kbuild robot?

Yeah indeed. Something went wrong and the patch service log has not
been updated for 3 days.. Let's check it.

Thanks,
Fengguang

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