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>
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c
index b2eff58..3cdce16 100644
--- a/fs/ntfs/dir.c
+++ b/fs/ntfs/dir.c
@@ -319,7 +319,7 @@
 	 * disk if necessary.
 	 */
 	page = ntfs_map_page(ia_mapping, vcn <<
-			dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT);
+			dir_ni->itype.index.vcn_size_bits >> PAGE_SHIFT);
 	if (IS_ERR(page)) {
 		ntfs_error(sb, "Failed to map directory index page, error %ld.",
 				-PTR_ERR(page));
@@ -331,9 +331,9 @@
 fast_descend_into_child_node:
 	/* Get to the index allocation block. */
 	ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
-			dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK));
+			dir_ni->itype.index.vcn_size_bits) & ~PAGE_MASK));
 	/* Bounds checks. */
-	if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) {
+	if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE) {
 		ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
 				"inode 0x%lx or driver bug.", dir_ni->mft_no);
 		goto unm_err_out;
@@ -366,7 +366,7 @@
 		goto unm_err_out;
 	}
 	index_end = (u8*)ia + dir_ni->itype.index.block_size;
-	if (index_end > kaddr + PAGE_CACHE_SIZE) {
+	if (index_end > kaddr + PAGE_SIZE) {
 		ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
 				"0x%lx crosses page boundary. Impossible! "
 				"Cannot access! This is probably a bug in the "
@@ -559,9 +559,9 @@
 			/* If vcn is in the same page cache page as old_vcn we
 			 * recycle the mapped page. */
 			if (old_vcn << vol->cluster_size_bits >>
-					PAGE_CACHE_SHIFT == vcn <<
+					PAGE_SHIFT == vcn <<
 					vol->cluster_size_bits >>
-					PAGE_CACHE_SHIFT)
+					PAGE_SHIFT)
 				goto fast_descend_into_child_node;
 			unlock_page(page);
 			ntfs_unmap_page(page);
@@ -1246,15 +1246,15 @@
 		goto iput_err_out;
 	}
 	/* Get the starting bit position in the current bitmap page. */
-	cur_bmp_pos = bmp_pos & ((PAGE_CACHE_SIZE * 8) - 1);
-	bmp_pos &= ~(u64)((PAGE_CACHE_SIZE * 8) - 1);
+	cur_bmp_pos = bmp_pos & ((PAGE_SIZE * 8) - 1);
+	bmp_pos &= ~(u64)((PAGE_SIZE * 8) - 1);
 get_next_bmp_page:
 	ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx",
-			(unsigned long long)bmp_pos >> (3 + PAGE_CACHE_SHIFT),
+			(unsigned long long)bmp_pos >> (3 + PAGE_SHIFT),
 			(unsigned long long)bmp_pos &
-			(unsigned long long)((PAGE_CACHE_SIZE * 8) - 1));
+			(unsigned long long)((PAGE_SIZE * 8) - 1));
 	bmp_page = ntfs_map_page(bmp_mapping,
-			bmp_pos >> (3 + PAGE_CACHE_SHIFT));
+			bmp_pos >> (3 + PAGE_SHIFT));
 	if (IS_ERR(bmp_page)) {
 		ntfs_error(sb, "Reading index bitmap failed.");
 		err = PTR_ERR(bmp_page);
@@ -1270,9 +1270,9 @@
 		 * If we have reached the end of the bitmap page, get the next
 		 * page, and put away the old one.
 		 */
-		if (unlikely((cur_bmp_pos >> 3) >= PAGE_CACHE_SIZE)) {
+		if (unlikely((cur_bmp_pos >> 3) >= PAGE_SIZE)) {
 			ntfs_unmap_page(bmp_page);
-			bmp_pos += PAGE_CACHE_SIZE * 8;
+			bmp_pos += PAGE_SIZE * 8;
 			cur_bmp_pos = 0;
 			goto get_next_bmp_page;
 		}
@@ -1285,8 +1285,8 @@
 	ntfs_debug("Handling index buffer 0x%llx.",
 			(unsigned long long)bmp_pos + cur_bmp_pos);
 	/* If the current index buffer is in the same page we reuse the page. */
-	if ((prev_ia_pos & (s64)PAGE_CACHE_MASK) !=
-			(ia_pos & (s64)PAGE_CACHE_MASK)) {
+	if ((prev_ia_pos & (s64)PAGE_MASK) !=
+			(ia_pos & (s64)PAGE_MASK)) {
 		prev_ia_pos = ia_pos;
 		if (likely(ia_page != NULL)) {
 			unlock_page(ia_page);
@@ -1296,7 +1296,7 @@
 		 * Map the page cache page containing the current ia_pos,
 		 * reading it from disk if necessary.
 		 */
-		ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_CACHE_SHIFT);
+		ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_SHIFT);
 		if (IS_ERR(ia_page)) {
 			ntfs_error(sb, "Reading index allocation data failed.");
 			err = PTR_ERR(ia_page);
@@ -1307,10 +1307,10 @@
 		kaddr = (u8*)page_address(ia_page);
 	}
 	/* Get the current index buffer. */
-	ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_CACHE_MASK &
-			~(s64)(ndir->itype.index.block_size - 1)));
+	ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_MASK &
+					  ~(s64)(ndir->itype.index.block_size - 1)));
 	/* Bounds checks. */
-	if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE)) {
+	if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_SIZE)) {
 		ntfs_error(sb, "Out of bounds check failed. Corrupt directory "
 				"inode 0x%lx or driver bug.", vdir->i_ino);
 		goto err_out;
@@ -1348,7 +1348,7 @@
 		goto err_out;
 	}
 	index_end = (u8*)ia + ndir->itype.index.block_size;
-	if (unlikely(index_end > kaddr + PAGE_CACHE_SIZE)) {
+	if (unlikely(index_end > kaddr + PAGE_SIZE)) {
 		ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode "
 				"0x%lx crosses page boundary. Impossible! "
 				"Cannot access! This is probably a bug in the "