[PATCH] fs: Add uoff_t

[PATCH] fs: Add uoff_t

[Matthew Wilcox (Oracle)]

In a recent commit, I inadvertently changed a comparison from being an
unsigned comparison (on 64-bit systems) to being a signed comparison
(which it had always been on 32-bit systems).  This led to a sporadic
fstests failure.

To make sure this comparison is always unsigned, introduce a new type,
uoff_t which is the unsigned version of loff_t.  Generally file sizes
are restricted to being a signed integer, but in these two places it is
convenient to pass -1 to indicate "up to the end of the file".

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/mm.h                     | 8 ++++----
 include/linux/shmem_fs.h               | 2 +-
 include/linux/types.h                  | 1 +
 include/uapi/asm-generic/posix_types.h | 1 +
 mm/shmem.c                             | 4 ++--
 mm/truncate.c                          | 2 +-
 6 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fe995cc3ba5c..a69ab017c370 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3650,10 +3650,10 @@ struct vm_unmapped_area_info {
 extern unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info);
 
 /* truncate.c */
-extern void truncate_inode_pages(struct address_space *, loff_t);
-extern void truncate_inode_pages_range(struct address_space *,
-				       loff_t lstart, loff_t lend);
-extern void truncate_inode_pages_final(struct address_space *);
+void truncate_inode_pages(struct address_space *mapping, loff_t lstart);
+void truncate_inode_pages_range(struct address_space *mapping, loff_t lstart,
+		uoff_t lend);
+void truncate_inode_pages_final(struct address_space *mapping);
 
 /* generic vm_area_ops exported for stackable file systems */
 extern vm_fault_t filemap_fault(struct vm_fault *vmf);
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 08f497673b06..94c6237acdc9 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -126,7 +126,7 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
 					pgoff_t index, gfp_t gfp_mask);
 int shmem_writeout(struct folio *folio, struct swap_iocb **plug,
 		struct list_head *folio_list);
-void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
+void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end);
 int shmem_unuse(unsigned int type);
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/include/linux/types.h b/include/linux/types.h
index 6dfdb8e8e4c3..d4437e9c452c 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -50,6 +50,7 @@ typedef __kernel_old_gid_t	old_gid_t;
 
 #if defined(__GNUC__)
 typedef __kernel_loff_t		loff_t;
+typedef __kernel_uoff_t		uoff_t;
 #endif
 
 /*
diff --git a/include/uapi/asm-generic/posix_types.h b/include/uapi/asm-generic/posix_types.h
index b5f7594eee7a..0a90ad92dbf3 100644
--- a/include/uapi/asm-generic/posix_types.h
+++ b/include/uapi/asm-generic/posix_types.h
@@ -86,6 +86,7 @@ typedef struct {
  */
 typedef __kernel_long_t	__kernel_off_t;
 typedef long long	__kernel_loff_t;
+typedef unsigned long long	__kernel_uoff_t;
 typedef __kernel_long_t	__kernel_old_time_t;
 #ifndef __KERNEL__
 typedef __kernel_long_t	__kernel_time_t;
diff --git a/mm/shmem.c b/mm/shmem.c
index 0a25ee095b86..728f2e04911e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1105,7 +1105,7 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index)
  * Remove range of pages and swap entries from page cache, and free them.
  * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate.
  */
-static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
+static void shmem_undo_range(struct inode *inode, loff_t lstart, uoff_t lend,
 								 bool unfalloc)
 {
 	struct address_space *mapping = inode->i_mapping;
@@ -1256,7 +1256,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 	shmem_recalc_inode(inode, 0, -nr_swaps_freed);
 }
 
-void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
+void shmem_truncate_range(struct inode *inode, loff_t lstart, uoff_t lend)
 {
 	shmem_undo_range(inode, lstart, lend, false);
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
diff --git a/mm/truncate.c b/mm/truncate.c
index d08340afc768..12467c1bd711 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -364,7 +364,7 @@ long mapping_evict_folio(struct address_space *mapping, struct folio *folio)
  * page aligned properly.
  */
 void truncate_inode_pages_range(struct address_space *mapping,
-				loff_t lstart, loff_t lend)
+				loff_t lstart, uoff_t lend)
 {
 	pgoff_t		start;		/* inclusive */
 	pgoff_t		end;		/* exclusive */
-- 
2.47.2

Re: [PATCH] fs: Add uoff_t

[Darrick J. Wong]

On Tue, Nov 18, 2025 at 03:29:33PM +0000, Matthew Wilcox (Oracle) wrote:
> In a recent commit, I inadvertently changed a comparison from being an
> unsigned comparison (on 64-bit systems) to being a signed comparison
> (which it had always been on 32-bit systems).  This led to a sporadic
> fstests failure.
> 
> To make sure this comparison is always unsigned, introduce a new type,
> uoff_t which is the unsigned version of loff_t.  Generally file sizes
> are restricted to being a signed integer, but in these two places it is
> convenient to pass -1 to indicate "up to the end of the file".

Soo... truncate_inode_pages passes 16EB as the lend parameter to
truncate_inode_pages_range now?  I suppose that makes sense, though the
casting to loff_t by that caller no longer does...

--D

> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  include/linux/mm.h                     | 8 ++++----
>  include/linux/shmem_fs.h               | 2 +-
>  include/linux/types.h                  | 1 +
>  include/uapi/asm-generic/posix_types.h | 1 +
>  mm/shmem.c                             | 4 ++--
>  mm/truncate.c                          | 2 +-
>  6 files changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index fe995cc3ba5c..a69ab017c370 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -3650,10 +3650,10 @@ struct vm_unmapped_area_info {
>  extern unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info);
>  
>  /* truncate.c */
> -extern void truncate_inode_pages(struct address_space *, loff_t);
> -extern void truncate_inode_pages_range(struct address_space *,
> -				       loff_t lstart, loff_t lend);
> -extern void truncate_inode_pages_final(struct address_space *);
> +void truncate_inode_pages(struct address_space *mapping, loff_t lstart);
> +void truncate_inode_pages_range(struct address_space *mapping, loff_t lstart,
> +		uoff_t lend);
> +void truncate_inode_pages_final(struct address_space *mapping);
>  
>  /* generic vm_area_ops exported for stackable file systems */
>  extern vm_fault_t filemap_fault(struct vm_fault *vmf);
> diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> index 08f497673b06..94c6237acdc9 100644
> --- a/include/linux/shmem_fs.h
> +++ b/include/linux/shmem_fs.h
> @@ -126,7 +126,7 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
>  					pgoff_t index, gfp_t gfp_mask);
>  int shmem_writeout(struct folio *folio, struct swap_iocb **plug,
>  		struct list_head *folio_list);
> -void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
> +void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end);
>  int shmem_unuse(unsigned int type);
>  
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> diff --git a/include/linux/types.h b/include/linux/types.h
> index 6dfdb8e8e4c3..d4437e9c452c 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -50,6 +50,7 @@ typedef __kernel_old_gid_t	old_gid_t;
>  
>  #if defined(__GNUC__)
>  typedef __kernel_loff_t		loff_t;
> +typedef __kernel_uoff_t		uoff_t;
>  #endif
>  
>  /*
> diff --git a/include/uapi/asm-generic/posix_types.h b/include/uapi/asm-generic/posix_types.h
> index b5f7594eee7a..0a90ad92dbf3 100644
> --- a/include/uapi/asm-generic/posix_types.h
> +++ b/include/uapi/asm-generic/posix_types.h
> @@ -86,6 +86,7 @@ typedef struct {
>   */
>  typedef __kernel_long_t	__kernel_off_t;
>  typedef long long	__kernel_loff_t;
> +typedef unsigned long long	__kernel_uoff_t;
>  typedef __kernel_long_t	__kernel_old_time_t;
>  #ifndef __KERNEL__
>  typedef __kernel_long_t	__kernel_time_t;
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 0a25ee095b86..728f2e04911e 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -1105,7 +1105,7 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index)
>   * Remove range of pages and swap entries from page cache, and free them.
>   * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate.
>   */
> -static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
> +static void shmem_undo_range(struct inode *inode, loff_t lstart, uoff_t lend,
>  								 bool unfalloc)
>  {
>  	struct address_space *mapping = inode->i_mapping;
> @@ -1256,7 +1256,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
>  	shmem_recalc_inode(inode, 0, -nr_swaps_freed);
>  }
>  
> -void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
> +void shmem_truncate_range(struct inode *inode, loff_t lstart, uoff_t lend)
>  {
>  	shmem_undo_range(inode, lstart, lend, false);
>  	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
> diff --git a/mm/truncate.c b/mm/truncate.c
> index d08340afc768..12467c1bd711 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -364,7 +364,7 @@ long mapping_evict_folio(struct address_space *mapping, struct folio *folio)
>   * page aligned properly.
>   */
>  void truncate_inode_pages_range(struct address_space *mapping,
> -				loff_t lstart, loff_t lend)
> +				loff_t lstart, uoff_t lend)
>  {
>  	pgoff_t		start;		/* inclusive */
>  	pgoff_t		end;		/* exclusive */
> -- 
> 2.47.2
> 
> 

Re: [PATCH] fs: Add uoff_t

[kernel test robot]

Hi Matthew,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on arnd-asm-generic/master linus/master v6.18-rc6 next-20251118]
[cannot apply to brauner-vfs/vfs.all]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Matthew-Wilcox-Oracle/fs-Add-uoff_t/20251118-233038
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251118152935.3735484-1-willy%40infradead.org
patch subject: [PATCH] fs: Add uoff_t
config: sh-allnoconfig (https://download.01.org/0day-ci/archive/20251119/202511190058.bebeyFBx-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251119/202511190058.bebeyFBx-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511190058.bebeyFBx-lkp@intel.com/

All errors (new ones prefixed by >>):

>> mm/shmem.c:5810:6: error: conflicting types for 'shmem_truncate_range'; have 'void(struct inode *, loff_t,  loff_t)' {aka 'void(struct inode *, long long int,  long long int)'}
    5810 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
         |      ^~~~~~~~~~~~~~~~~~~~
   In file included from mm/shmem.c:36:
   include/linux/shmem_fs.h:129:6: note: previous declaration of 'shmem_truncate_range' with type 'void(struct inode *, loff_t,  uoff_t)' {aka 'void(struct inode *, long long int,  long long unsigned int)'}
     129 | void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end);
         |      ^~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/linkage.h:7,
                    from arch/sh/include/asm/bug.h:5,
                    from include/linux/bug.h:5,
                    from include/linux/vfsdebug.h:5,
                    from include/linux/fs.h:5,
                    from mm/shmem.c:24:
   mm/shmem.c:5814:19: error: conflicting types for 'shmem_truncate_range'; have 'void(struct inode *, loff_t,  loff_t)' {aka 'void(struct inode *, long long int,  long long int)'}
    5814 | EXPORT_SYMBOL_GPL(shmem_truncate_range);
         |                   ^~~~~~~~~~~~~~~~~~~~
   include/linux/export.h:76:28: note: in definition of macro '__EXPORT_SYMBOL'
      76 |         extern typeof(sym) sym;                                 \
         |                            ^~~
   include/linux/export.h:90:41: note: in expansion of macro '_EXPORT_SYMBOL'
      90 | #define EXPORT_SYMBOL_GPL(sym)          _EXPORT_SYMBOL(sym, "GPL")
         |                                         ^~~~~~~~~~~~~~
   mm/shmem.c:5814:1: note: in expansion of macro 'EXPORT_SYMBOL_GPL'
    5814 | EXPORT_SYMBOL_GPL(shmem_truncate_range);
         | ^~~~~~~~~~~~~~~~~
   include/linux/shmem_fs.h:129:6: note: previous declaration of 'shmem_truncate_range' with type 'void(struct inode *, loff_t,  uoff_t)' {aka 'void(struct inode *, long long int,  long long unsigned int)'}
     129 | void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end);
         |      ^~~~~~~~~~~~~~~~~~~~
   mm/shmem.c: In function '__shmem_file_setup':
   mm/shmem.c:5838:23: warning: unused variable 'flags' [-Wunused-variable]
    5838 |         unsigned long flags = (vm_flags & VM_NORESERVE) ? SHMEM_F_NORESERVE : 0;
         |                       ^~~~~


vim +5810 mm/shmem.c

c01d5b300774d1 Hugh Dickins 2016-07-26  5809  
41ffe5d5ceef7f Hugh Dickins 2011-08-03 @5810  void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
94c1e62df4494b Hugh Dickins 2011-06-27  5811  {
41ffe5d5ceef7f Hugh Dickins 2011-08-03  5812  	truncate_inode_pages_range(inode->i_mapping, lstart, lend);
94c1e62df4494b Hugh Dickins 2011-06-27  5813  }
94c1e62df4494b Hugh Dickins 2011-06-27  5814  EXPORT_SYMBOL_GPL(shmem_truncate_range);
94c1e62df4494b Hugh Dickins 2011-06-27  5815  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] fs: Add uoff_t

[kernel test robot]

Hi Matthew,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on arnd-asm-generic/master linus/master v6.18-rc6 next-20251118]
[cannot apply to brauner-vfs/vfs.all]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Matthew-Wilcox-Oracle/fs-Add-uoff_t/20251118-233038
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251118152935.3735484-1-willy%40infradead.org
patch subject: [PATCH] fs: Add uoff_t
config: arm-allnoconfig (https://download.01.org/0day-ci/archive/20251119/202511190917.pXdJRhD8-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 0bba1e76581bad04e7d7f09f5115ae5e2989e0d9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251119/202511190917.pXdJRhD8-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511190917.pXdJRhD8-lkp@intel.com/

All errors (new ones prefixed by >>):

>> mm/shmem.c:5810:6: error: conflicting types for 'shmem_truncate_range'
    5810 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
         |      ^
   include/linux/shmem_fs.h:129:6: note: previous declaration is here
     129 | void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end);
         |      ^
   mm/shmem.c:5838:16: warning: unused variable 'flags' [-Wunused-variable]
    5838 |         unsigned long flags = (vm_flags & VM_NORESERVE) ? SHMEM_F_NORESERVE : 0;
         |                       ^~~~~
   1 warning and 1 error generated.


vim +/shmem_truncate_range +5810 mm/shmem.c

c01d5b300774d13 Hugh Dickins 2016-07-26  5809  
41ffe5d5ceef7f7 Hugh Dickins 2011-08-03 @5810  void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
94c1e62df4494b7 Hugh Dickins 2011-06-27  5811  {
41ffe5d5ceef7f7 Hugh Dickins 2011-08-03  5812  	truncate_inode_pages_range(inode->i_mapping, lstart, lend);
94c1e62df4494b7 Hugh Dickins 2011-06-27  5813  }
94c1e62df4494b7 Hugh Dickins 2011-06-27  5814  EXPORT_SYMBOL_GPL(shmem_truncate_range);
94c1e62df4494b7 Hugh Dickins 2011-06-27  5815  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki