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>

5 files changed, 8 insertions, 8 deletions

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index d7709e3..9e5eddb 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -628,7 +628,7 @@ void flush_dcache_page(struct page *page)
 
 		/* kernel reading from page with U-mapping */
 		phys_addr_t paddr = (unsigned long)page_address(page);
-		unsigned long vaddr = page->index << PAGE_CACHE_SHIFT;
+		unsigned long vaddr = page->index << PAGE_SHIFT;
 
 		if (addr_not_cache_congruent(paddr, vaddr))
 			__flush_dcache_page(paddr, vaddr);
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index d0ba3551..3cced84 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -235,7 +235,7 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page)
 	 */
 	if (mapping && cache_is_vipt_aliasing())
 		flush_pfn_alias(page_to_pfn(page),
-				page->index << PAGE_CACHE_SHIFT);
+				page->index << PAGE_SHIFT);
 }
 
 static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
@@ -250,7 +250,7 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
 	 *   data in the current VM view associated with this page.
 	 * - aliasing VIPT: we only need to find one mapping of this page.
 	 */
-	pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff = page->index;
 
 	flush_dcache_mmap_lock(mapping);
 	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 91c2a39..6700127 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -319,7 +319,7 @@ void flush_dcache_page(struct page *page)
 	if (!mapping)
 		return;
 
-	pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff = page->index;
 
 	/* We have carefully arranged in arch_get_unmapped_area() that
 	 * *any* mappings of a file are always congruently mapped (whether
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index dfa8638..6ca5f05 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -732,8 +732,8 @@ spufs_fill_super(struct super_block *sb, void *data, int silent)
 		return -ENOMEM;
 
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
-	sb->s_blocksize = PAGE_CACHE_SIZE;
-	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
 	sb->s_magic = SPUFS_MAGIC;
 	sb->s_op = &s_ops;
 	sb->s_fs_info = info;
diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 0f3da2c..255c7ee 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -278,8 +278,8 @@ static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->uid = current_uid();
 	sbi->gid = current_gid();
 	sb->s_fs_info = sbi;
-	sb->s_blocksize = PAGE_CACHE_SIZE;
-	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
 	sb->s_magic = HYPFS_MAGIC;
 	sb->s_op = &hypfs_s_ops;
 	if (hypfs_parse_options(data, sb))