[3/3] mm: make pagoff_t type 64-bit
diff mbox

Message ID 1481461003-14361-4-git-send-email-ynorov@caviumnetworks.com
State New
Headers show

Commit Message

Yury Norov Dec. 11, 2016, 12:56 p.m. UTC
Also fix related interfaces

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
---
 fs/btrfs/extent_io.c       | 2 +-
 fs/ext2/dir.c              | 4 ++--
 include/linux/mm.h         | 9 +++++----
 include/linux/radix-tree.h | 8 ++++----
 include/linux/types.h      | 2 +-
 lib/radix-tree.c           | 8 ++++----
 mm/debug.c                 | 2 +-
 mm/internal.h              | 2 +-
 mm/memory.c                | 4 ++--
 mm/mmap.c                  | 7 ++++---
 mm/readahead.c             | 4 ++--
 mm/util.c                  | 3 ++-
 12 files changed, 29 insertions(+), 26 deletions(-)

Comments

Arnd Bergmann Dec. 11, 2016, 2:59 p.m. UTC | #1
On Sunday, December 11, 2016 6:26:42 PM CET Yury Norov wrote:
> Also fix related interfaces
> 
> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> ---
>  fs/btrfs/extent_io.c       | 2 +-
>  fs/ext2/dir.c              | 4 ++--
>  include/linux/mm.h         | 9 +++++----
>  include/linux/radix-tree.h | 8 ++++----
>  include/linux/types.h      | 2 +-
>  lib/radix-tree.c           | 8 ++++----
>  mm/debug.c                 | 2 +-
>  mm/internal.h              | 2 +-
>  mm/memory.c                | 4 ++--
>  mm/mmap.c                  | 7 ++++---
>  mm/readahead.c             | 4 ++--
>  mm/util.c                  | 3 ++-
>  12 files changed, 29 insertions(+), 26 deletions(-)
> 

Thanks Yury for the demonstration. I think this would put the nail
in the coffin of the idea of mmap64 even for Pavel, who didn't
seem convinced already.

Changing all those interfaces and structure, struct page in particular,
is clearly too costly for any advantage we might have otherwise
gained.

	Arnd
Yury Norov Dec. 16, 2016, 10:55 a.m. UTC | #2
On Sun, Dec 11, 2016 at 03:59:01PM +0100, Arnd Bergmann wrote:
> On Sunday, December 11, 2016 6:26:42 PM CET Yury Norov wrote:
> > Also fix related interfaces
> > 
> > Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> 
> Thanks Yury for the demonstration. I think this would put the nail
> in the coffin of the idea of mmap64 even for Pavel, who didn't
> seem convinced already.
> 
> Changing all those interfaces and structure, struct page in particular,
> is clearly too costly for any advantage we might have otherwise
> gained.
> 
> 	Arnd

To be complete, we have 3 options:
 1 leave things as is. 32-bit architectures will have no option to
   mmap big offsets, and no one cares - as usual.
 2 add mmap64() for compat arches only. This way we don't need patch
   3, and arches like aarch32 or aarch64/ilp32 will enjoy true 64-bit
   offsets.
 3 introduce CONFIG_64_BIT_PGOFF_T, and let Pavel enable it if he has
   to work with big files on 32-bit arches.

The most realistic approach for me is 1 because I never heard about
64-bit pgoff_t requests, except Pavel's one. Thinking about
aarch64/ilp32, we probably need second approach. This is only 2 simple
patches that are already there, and one patch in glibc. It will let
32-bit software work in 64-bit environment more smoothly. Cavium
people should be completely satisfied with 2.

Third is more looking like research exercise than something we need
in practice.

The only thing that makes me sad is that we proudly declare 64-bit
off_t in new 32-bit ABIs but in fact we lie, at least in this
specific case. We should add corresponding checks on glibc side at
least. It's also simple.

Yury.
Arnd Bergmann Dec. 16, 2016, 11:02 a.m. UTC | #3
On Friday, December 16, 2016 4:25:14 PM CET Yury Norov wrote:
> On Sun, Dec 11, 2016 at 03:59:01PM +0100, Arnd Bergmann wrote:
> > On Sunday, December 11, 2016 6:26:42 PM CET Yury Norov wrote:
> > > Also fix related interfaces
> > > 
> > > Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> > 
> > Thanks Yury for the demonstration. I think this would put the nail
> > in the coffin of the idea of mmap64 even for Pavel, who didn't
> > seem convinced already.
> > 
> > Changing all those interfaces and structure, struct page in particular,
> > is clearly too costly for any advantage we might have otherwise
> > gained.
> > 
> >       Arnd
> 
> To be complete, we have 3 options:
>  1 leave things as is. 32-bit architectures will have no option to
>    mmap big offsets, and no one cares - as usual.
>  2 add mmap64() for compat arches only. This way we don't need patch
>    3, and arches like aarch32 or aarch64/ilp32 will enjoy true 64-bit
>    offsets.
>  3 introduce CONFIG_64_BIT_PGOFF_T, and let Pavel enable it if he has
>    to work with big files on 32-bit arches.
> 
> The most realistic approach for me is 1 because I never heard about
> 64-bit pgoff_t requests, except Pavel's one. Thinking about
> aarch64/ilp32, we probably need second approach. This is only 2 simple
> patches that are already there, and one patch in glibc. It will let
> 32-bit software work in 64-bit environment more smoothly. Cavium
> people should be completely satisfied with 2.

Agreed: If there is a serious request from Cavium or Huawei (which
are also very interested in this feature) and a specific use case,
we can still do 2 easily.

> Third is more looking like research exercise than something we need
> in practice.

Right.

> The only thing that makes me sad is that we proudly declare 64-bit
> off_t in new 32-bit ABIs but in fact we lie, at least in this
> specific case. We should add corresponding checks on glibc side at
> least. It's also simple.

Well, the only thing we are really saying there is that we support
more than 32-bit, and that the ABI uses 64-bit. Actually doing 64-bit
offsets within (very sparse) files probably also fails on 64-bit
architectures, at least on some file systems.

	Arnd
Christoph Hellwig Dec. 18, 2016, 9:23 a.m. UTC | #4
On Fri, Dec 16, 2016 at 04:25:14PM +0530, Yury Norov wrote:
>  1 leave things as is. 32-bit architectures will have no option to
>    mmap big offsets, and no one cares - as usual.

And that's the only sensible option.

Patch
diff mbox

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8ed05d9..f4c9318 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3436,7 +3436,7 @@  static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 		set_range_writeback(tree, cur, cur + iosize - 1);
 		if (!PageWriteback(page)) {
 			btrfs_err(BTRFS_I(inode)->root->fs_info,
-				   "page %lu not writeback, cur %llu end %llu",
+				   "page %llu not writeback, cur %llu end %llu",
 			       page->index, cur, end);
 		}
 
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index d9650c9..c01b76e 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -174,7 +174,7 @@  static bool ext2_check_page(struct page *page, int quiet)
 	error = "inode out of bounds";
 bad_entry:
 	if (!quiet)
-		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
+		ext2_error(sb, __func__, "bad entry in directory #%llu: : %s - "
 			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
 			dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs,
 			(unsigned long) le32_to_cpu(p->inode),
@@ -184,7 +184,7 @@  static bool ext2_check_page(struct page *page, int quiet)
 	if (!quiet) {
 		p = (ext2_dirent *)(kaddr + offs);
 		ext2_error(sb, "ext2_check_page",
-			"entry in directory #%lu spans the page boundary"
+			"entry in directory #%llu spans the page boundary"
 			"offset=%lu, inode=%lu",
 			dir->i_ino, (page->index<<PAGE_SHIFT)+offs,
 			(unsigned long) le32_to_cpu(p->inode));
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a92c8d7..33d9150 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2022,19 +2022,20 @@  extern int install_special_mapping(struct mm_struct *mm,
 				   unsigned long addr, unsigned long len,
 				   unsigned long flags, struct page **pages);
 
-extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
+extern unsigned long get_unmapped_area(struct file *, unsigned long,
+		unsigned long, pgoff_t, unsigned long);
 
 extern unsigned long mmap_region(struct file *file, unsigned long addr,
-	unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
+	unsigned long len, vm_flags_t vm_flags, pgoff_t pgoff);
 extern unsigned long do_mmap(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot, unsigned long flags,
-	vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate);
+	vm_flags_t vm_flags, pgoff_t pgoff, unsigned long *populate);
 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
 
 static inline unsigned long
 do_mmap_pgoff(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot, unsigned long flags,
-	unsigned long pgoff, unsigned long *populate)
+	pgoff_t pgoff, unsigned long *populate)
 {
 	return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate);
 }
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index af3581b..1781bb7 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -287,7 +287,7 @@  unsigned int radix_tree_gang_lookup(struct radix_tree_root *root,
 			void **results, unsigned long first_index,
 			unsigned int max_items);
 unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root,
-			void ***results, unsigned long *indices,
+			void ***results, unsigned long long *indices,
 			unsigned long first_index, unsigned int max_items);
 int radix_tree_preload(gfp_t gfp_mask);
 int radix_tree_maybe_preload(gfp_t gfp_mask);
@@ -308,7 +308,7 @@  radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
 		unsigned long first_index, unsigned int max_items,
 		unsigned int tag);
 unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
-		unsigned long *first_indexp, unsigned long last_index,
+		unsigned long long *first_indexp, unsigned long last_index,
 		unsigned long nr_to_tag,
 		unsigned int fromtag, unsigned int totag);
 int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
@@ -335,8 +335,8 @@  static inline void radix_tree_preload_end(void)
  * radix tree tag.
  */
 struct radix_tree_iter {
-	unsigned long	index;
-	unsigned long	next_index;
+	unsigned long long	index;
+	unsigned long long	next_index;
 	unsigned long	tags;
 #ifdef CONFIG_RADIX_TREE_MULTIORDER
 	unsigned int	shift;
diff --git a/include/linux/types.h b/include/linux/types.h
index baf7183..1e711c1 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -137,7 +137,7 @@  typedef unsigned long blkcnt_t;
 /*
  * The type of an index into the pagecache.
  */
-#define pgoff_t unsigned long
+#define pgoff_t unsigned long long
 
 /*
  * A dma_addr_t can hold any valid DMA address, i.e., any address returned
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 0d1d23e..afb49381 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -97,7 +97,7 @@  static inline unsigned long get_slot_offset(struct radix_tree_node *parent,
 }
 
 static unsigned int radix_tree_descend(struct radix_tree_node *parent,
-			struct radix_tree_node **nodep, unsigned long index)
+			struct radix_tree_node **nodep, unsigned long long index)
 {
 	unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK;
 	void **entry = rcu_dereference_raw(parent->slots[offset]);
@@ -1040,14 +1040,14 @@  EXPORT_SYMBOL(radix_tree_next_chunk);
  * be prepared to handle that.
  */
 unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
-		unsigned long *first_indexp, unsigned long last_index,
+		unsigned long long *first_indexp, unsigned long last_index,
 		unsigned long nr_to_tag,
 		unsigned int iftag, unsigned int settag)
 {
 	struct radix_tree_node *parent, *node, *child;
 	unsigned long maxindex;
 	unsigned long tagged = 0;
-	unsigned long index = *first_indexp;
+	unsigned long long index = *first_indexp;
 
 	radix_tree_load_root(root, &child, &maxindex);
 	last_index = min(last_index, maxindex);
@@ -1195,7 +1195,7 @@  EXPORT_SYMBOL(radix_tree_gang_lookup);
  */
 unsigned int
 radix_tree_gang_lookup_slot(struct radix_tree_root *root,
-			void ***results, unsigned long *indices,
+			void ***results, unsigned long long *indices,
 			unsigned long first_index, unsigned int max_items)
 {
 	struct radix_tree_iter iter;
diff --git a/mm/debug.c b/mm/debug.c
index 9feb699..a568fc8 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -49,7 +49,7 @@  void __dump_page(struct page *page, const char *reason)
 	 */
 	int mapcount = PageSlab(page) ? 0 : page_mapcount(page);
 
-	pr_emerg("page:%p count:%d mapcount:%d mapping:%p index:%#lx",
+	pr_emerg("page:%p count:%d mapcount:%d mapping:%p index:%#llx",
 		  page, page_ref_count(page), mapcount,
 		  page->mapping, page_to_pgoff(page));
 	if (PageCompound(page))
diff --git a/mm/internal.h b/mm/internal.h
index 537ac99..8027eac 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -447,7 +447,7 @@  extern u32 hwpoison_filter_enable;
 
 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
         unsigned long, unsigned long,
-        unsigned long, unsigned long);
+        unsigned long, pgoff_t);
 
 extern void set_pageblock_order(void);
 unsigned long reclaim_clean_pages_from_list(struct zone *zone,
diff --git a/mm/memory.c b/mm/memory.c
index e18c57b..c05d534 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -688,7 +688,7 @@  static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
 		 (long long)pte_val(pte), (long long)pmd_val(*pmd));
 	if (page)
 		dump_page(page, "bad pte");
-	pr_alert("addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n",
+	pr_alert("addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%llx\n",
 		 (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index);
 	/*
 	 * Choose text because data symbols depend on CONFIG_KALLSYMS_ALL=y
@@ -3133,7 +3133,7 @@  static int do_fault_around(struct fault_env *fe, pgoff_t start_pgoff)
 	end_pgoff = start_pgoff -
 		((fe->address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +
 		PTRS_PER_PTE - 1;
-	end_pgoff = min3(end_pgoff, vma_pages(fe->vma) + fe->vma->vm_pgoff - 1,
+	end_pgoff = min3(end_pgoff, (pgoff_t) vma_pages(fe->vma) + fe->vma->vm_pgoff - 1,
 			start_pgoff + nr_pages - 1);
 
 	if (pmd_none(*fe->pmd)) {
diff --git a/mm/mmap.c b/mm/mmap.c
index 6c6b95a..cf50232 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -9,6 +9,7 @@ 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kernel.h>
+#include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/backing-dev.h>
 #include <linux/mm.h>
@@ -1304,7 +1305,7 @@  static inline int mlock_future_check(struct mm_struct *mm,
 unsigned long do_mmap(struct file *file, unsigned long addr,
 			unsigned long len, unsigned long prot,
 			unsigned long flags, vm_flags_t vm_flags,
-			unsigned long pgoff, unsigned long *populate)
+			pgoff_t pgoff, unsigned long *populate)
 {
 	struct mm_struct *mm = current->mm;
 	int pkey = 0;
@@ -1624,7 +1625,7 @@  static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags)
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
-		unsigned long len, vm_flags_t vm_flags, unsigned long pgoff)
+		unsigned long len, vm_flags_t vm_flags, pgoff_t pgoff)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma, *prev;
@@ -2088,7 +2089,7 @@  arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 
 unsigned long
 get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
-		unsigned long pgoff, unsigned long flags)
+		pgoff_t pgoff, unsigned long flags)
 {
 	unsigned long (*get_area)(struct file *, unsigned long,
 				  unsigned long, unsigned long, unsigned long);
diff --git a/mm/readahead.c b/mm/readahead.c
index c8a955b..902bad8 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -332,8 +332,8 @@  static pgoff_t count_history_pages(struct address_space *mapping,
 static int try_context_readahead(struct address_space *mapping,
 				 struct file_ra_state *ra,
 				 pgoff_t offset,
-				 unsigned long req_size,
-				 unsigned long max)
+				 unsigned long long req_size,
+				 unsigned long long max)
 {
 	pgoff_t size;
 
diff --git a/mm/util.c b/mm/util.c
index 1a41553..51fae99 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -2,6 +2,7 @@ 
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/compiler.h>
+#include <linux/types.h>
 #include <linux/export.h>
 #include <linux/err.h>
 #include <linux/sched.h>
@@ -292,7 +293,7 @@  EXPORT_SYMBOL_GPL(get_user_pages_fast);
 
 unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot,
-	unsigned long flag, unsigned long pgoff)
+	unsigned long flag, pgoff_t pgoff)
 {
 	unsigned long ret;
 	struct mm_struct *mm = current->mm;