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/mft.c b/fs/ntfs/mft.c
index 3014a36..37b2501 100644
--- a/fs/ntfs/mft.c
+++ b/fs/ntfs/mft.c
@@ -61,16 +61,16 @@
 	 * here if the volume was that big...
 	 */
 	index = (u64)ni->mft_no << vol->mft_record_size_bits >>
-			PAGE_CACHE_SHIFT;
-	ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
+			PAGE_SHIFT;
+	ofs = (ni->mft_no << vol->mft_record_size_bits) & ~PAGE_MASK;
 
 	i_size = i_size_read(mft_vi);
 	/* The maximum valid index into the page cache for $MFT's data. */
-	end_index = i_size >> PAGE_CACHE_SHIFT;
+	end_index = i_size >> PAGE_SHIFT;
 
 	/* If the wanted index is out of bounds the mft record doesn't exist. */
 	if (unlikely(index >= end_index)) {
-		if (index > end_index || (i_size & ~PAGE_CACHE_MASK) < ofs +
+		if (index > end_index || (i_size & ~PAGE_MASK) < ofs +
 				vol->mft_record_size) {
 			page = ERR_PTR(-ENOENT);
 			ntfs_error(vol->sb, "Attempt to read mft record 0x%lx, "
@@ -487,7 +487,7 @@
 	}
 	/* Get the page containing the mirror copy of the mft record @m. */
 	page = ntfs_map_page(vol->mftmirr_ino->i_mapping, mft_no >>
-			(PAGE_CACHE_SHIFT - vol->mft_record_size_bits));
+			(PAGE_SHIFT - vol->mft_record_size_bits));
 	if (IS_ERR(page)) {
 		ntfs_error(vol->sb, "Failed to map mft mirror page.");
 		err = PTR_ERR(page);
@@ -497,7 +497,7 @@
 	BUG_ON(!PageUptodate(page));
 	ClearPageUptodate(page);
 	/* Offset of the mft mirror record inside the page. */
-	page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
+	page_ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_MASK;
 	/* The address in the page of the mirror copy of the mft record @m. */
 	kmirr = page_address(page) + page_ofs;
 	/* Copy the mst protected mft record to the mirror. */
@@ -1178,8 +1178,8 @@
 	for (; pass <= 2;) {
 		/* Cap size to pass_end. */
 		ofs = data_pos >> 3;
-		page_ofs = ofs & ~PAGE_CACHE_MASK;
-		size = PAGE_CACHE_SIZE - page_ofs;
+		page_ofs = ofs & ~PAGE_MASK;
+		size = PAGE_SIZE - page_ofs;
 		ll = ((pass_end + 7) >> 3) - ofs;
 		if (size > ll)
 			size = ll;
@@ -1190,7 +1190,7 @@
 		 */
 		if (size) {
 			page = ntfs_map_page(mftbmp_mapping,
-					ofs >> PAGE_CACHE_SHIFT);
+					ofs >> PAGE_SHIFT);
 			if (IS_ERR(page)) {
 				ntfs_error(vol->sb, "Failed to read mft "
 						"bitmap, aborting.");
@@ -1328,13 +1328,13 @@
 	 */
 	ll = lcn >> 3;
 	page = ntfs_map_page(vol->lcnbmp_ino->i_mapping,
-			ll >> PAGE_CACHE_SHIFT);
+			ll >> PAGE_SHIFT);
 	if (IS_ERR(page)) {
 		up_write(&mftbmp_ni->runlist.lock);
 		ntfs_error(vol->sb, "Failed to read from lcn bitmap.");
 		return PTR_ERR(page);
 	}
-	b = (u8*)page_address(page) + (ll & ~PAGE_CACHE_MASK);
+	b = (u8*)page_address(page) + (ll & ~PAGE_MASK);
 	tb = 1 << (lcn & 7ull);
 	down_write(&vol->lcnbmp_lock);
 	if (*b != 0xff && !(*b & tb)) {
@@ -2103,14 +2103,14 @@
 	 * The index into the page cache and the offset within the page cache
 	 * page of the wanted mft record.
 	 */
-	index = mft_no << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT;
-	ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
+	index = mft_no << vol->mft_record_size_bits >> PAGE_SHIFT;
+	ofs = (mft_no << vol->mft_record_size_bits) & ~PAGE_MASK;
 	/* The maximum valid index into the page cache for $MFT's data. */
 	i_size = i_size_read(mft_vi);
-	end_index = i_size >> PAGE_CACHE_SHIFT;
+	end_index = i_size >> PAGE_SHIFT;
 	if (unlikely(index >= end_index)) {
 		if (unlikely(index > end_index || ofs + vol->mft_record_size >=
-				(i_size & ~PAGE_CACHE_MASK))) {
+				(i_size & ~PAGE_MASK))) {
 			ntfs_error(vol->sb, "Tried to format non-existing mft "
 					"record 0x%llx.", (long long)mft_no);
 			return -ENOENT;
@@ -2515,8 +2515,8 @@
 	 * We now have allocated and initialized the mft record.  Calculate the
 	 * index of and the offset within the page cache page the record is in.
 	 */
-	index = bit << vol->mft_record_size_bits >> PAGE_CACHE_SHIFT;
-	ofs = (bit << vol->mft_record_size_bits) & ~PAGE_CACHE_MASK;
+	index = bit << vol->mft_record_size_bits >> PAGE_SHIFT;
+	ofs = (bit << vol->mft_record_size_bits) & ~PAGE_MASK;
 	/* Read, map, and pin the page containing the mft record. */
 	page = ntfs_map_page(vol->mft_ino->i_mapping, index);
 	if (IS_ERR(page)) {