mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 20 insertions, 20 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index 7598b552ae03..b00272810871 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -118,7 +118,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
                 return -EIO;
 
         if (page_has_private(page))
-                do_invalidatepage(page, 0, PAGE_CACHE_SIZE);
+                do_invalidatepage(page, 0, PAGE_SIZE);
 
         /*
          * Some filesystems seem to re-dirty the page even after
@@ -159,8 +159,8 @@ int truncate_inode_page(struct address_space *mapping, struct page *page)
 {
         if (page_mapped(page)) {
                 unmap_mapping_range(mapping,
-                                   (loff_t)page->index << PAGE_CACHE_SHIFT,
-                                   PAGE_CACHE_SIZE, 0);
+                                   (loff_t)page->index << PAGE_SHIFT,
+                                   PAGE_SIZE, 0);
         }
         return truncate_complete_page(mapping, page);
 }
@@ -241,8 +241,8 @@ void truncate_inode_pages_range(struct address_space *mapping,
                 return;
 
         /* Offsets within partial pages */
-        partial_start = lstart & (PAGE_CACHE_SIZE - 1);
-        partial_end = (lend + 1) & (PAGE_CACHE_SIZE - 1);
+        partial_start = lstart & (PAGE_SIZE - 1);
+        partial_end = (lend + 1) & (PAGE_SIZE - 1);
 
         /*
          * 'start' and 'end' always covers the range of pages to be fully
@@ -250,7 +250,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
          * start of the range and 'partial_end' at the end of the range.
          * Note that 'end' is exclusive while 'lend' is inclusive.
          */
-        start = (lstart + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+        start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT;
         if (lend == -1)
                 /*
                  * lend == -1 indicates end-of-file so we have to set 'end'
@@ -259,7 +259,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                  */
                 end = -1;
         else
-                end = (lend + 1) >> PAGE_CACHE_SHIFT;
+                end = (lend + 1) >> PAGE_SHIFT;
 
         pagevec_init(&pvec, 0);
         index = start;
@@ -298,7 +298,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
         if (partial_start) {
                 struct page *page = find_lock_page(mapping, start - 1);
                 if (page) {
-                        unsigned int top = PAGE_CACHE_SIZE;
+                        unsigned int top = PAGE_SIZE;
                         if (start > end) {
                                 /* Truncation within a single page */
                                 top = partial_end;
@@ -311,7 +311,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                                 do_invalidatepage(page, partial_start,
                                                   top - partial_start);
                         unlock_page(page);
-                        page_cache_release(page);
+                        put_page(page);
                 }
         }
         if (partial_end) {
@@ -324,7 +324,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                                 do_invalidatepage(page, 0,
                                                   partial_end);
                         unlock_page(page);
-                        page_cache_release(page);
+                        put_page(page);
                 }
         }
         /*
@@ -538,7 +538,7 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
         if (mapping->a_ops->freepage)
                 mapping->a_ops->freepage(page);
 
-        page_cache_release(page);       /* pagecache ref */
+        put_page(page); /* pagecache ref */
         return 1;
 failed:
         spin_unlock_irqrestore(&mapping->tree_lock, flags);
@@ -608,18 +608,18 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                                          * Zap the rest of the file in one hit.
                                          */
                                         unmap_mapping_range(mapping,
-                                           (loff_t)index << PAGE_CACHE_SHIFT,
+                                           (loff_t)index << PAGE_SHIFT,
                                            (loff_t)(1 + end - index)
-                                                         << PAGE_CACHE_SHIFT,
-                                            0);
+                                                         << PAGE_SHIFT,
+                                                         0);
                                         did_range_unmap = 1;
                                 } else {
                                         /*
                                          * Just zap this page
                                          */
                                         unmap_mapping_range(mapping,
-                                           (loff_t)index << PAGE_CACHE_SHIFT,
-                                           PAGE_CACHE_SIZE, 0);
+                                           (loff_t)index << PAGE_SHIFT,
+                                           PAGE_SIZE, 0);
                                 }
                         }
                         BUG_ON(page_mapped(page));
@@ -744,14 +744,14 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
 
         WARN_ON(to > inode->i_size);
 
-        if (from >= to || bsize == PAGE_CACHE_SIZE)
+        if (from >= to || bsize == PAGE_SIZE)
                 return;
         /* Page straddling @from will not have any hole block created? */
         rounded_from = round_up(from, bsize);
-        if (to <= rounded_from || !(rounded_from & (PAGE_CACHE_SIZE - 1)))
+        if (to <= rounded_from || !(rounded_from & (PAGE_SIZE - 1)))
                 return;
 
-        index = from >> PAGE_CACHE_SHIFT;
+        index = from >> PAGE_SHIFT;
         page = find_lock_page(inode->i_mapping, index);
         /* Page not cached? Nothing to do */
         if (!page)
@@ -763,7 +763,7 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
         if (page_mkclean(page))
                 set_page_dirty(page);
         unlock_page(page);
-        page_cache_release(page);
+        put_page(page);
 }
 EXPORT_SYMBOL(pagecache_isize_extended);