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, 16 insertions, 16 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ef38f01c1795..a79f9269831e 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -466,7 +466,7 @@ more:
 			ret += zlen;
 		}
 
-		didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
+		didpages = (page_align + ret) >> PAGE_SHIFT;
 		pos += ret;
 		read = pos - off;
 		left -= ret;
@@ -806,8 +806,8 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
 
 	if (write) {
 		ret = invalidate_inode_pages2_range(inode->i_mapping,
-					pos >> PAGE_CACHE_SHIFT,
-					(pos + count) >> PAGE_CACHE_SHIFT);
+					pos >> PAGE_SHIFT,
+					(pos + count) >> PAGE_SHIFT);
 		if (ret < 0)
 			dout("invalidate_inode_pages2_range returned %d\n", ret);
 
@@ -872,7 +872,7 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
 			 * may block.
 			 */
 			truncate_inode_pages_range(inode->i_mapping, pos,
-					(pos+len) | (PAGE_CACHE_SIZE - 1));
+					(pos+len) | (PAGE_SIZE - 1));
 
 			osd_req_op_init(req, 1, CEPH_OSD_OP_STARTSYNC, 0);
 		}
@@ -1006,8 +1006,8 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
 		return ret;
 
 	ret = invalidate_inode_pages2_range(inode->i_mapping,
-					    pos >> PAGE_CACHE_SHIFT,
-					    (pos + count) >> PAGE_CACHE_SHIFT);
+					    pos >> PAGE_SHIFT,
+					    (pos + count) >> PAGE_SHIFT);
 	if (ret < 0)
 		dout("invalidate_inode_pages2_range returned %d\n", ret);
 
@@ -1036,7 +1036,7 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
 		 * write from beginning of first page,
 		 * regardless of io alignment
 		 */
-		num_pages = (len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+		num_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 
 		pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
 		if (IS_ERR(pages)) {
@@ -1159,7 +1159,7 @@ again:
 	dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
 	     inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
 	if (pinned_page) {
-		page_cache_release(pinned_page);
+		put_page(pinned_page);
 		pinned_page = NULL;
 	}
 	ceph_put_cap_refs(ci, got);
@@ -1188,10 +1188,10 @@ again:
 		if (retry_op == READ_INLINE) {
 			BUG_ON(ret > 0 || read > 0);
 			if (iocb->ki_pos < i_size &&
-			    iocb->ki_pos < PAGE_CACHE_SIZE) {
+			    iocb->ki_pos < PAGE_SIZE) {
 				loff_t end = min_t(loff_t, i_size,
 						   iocb->ki_pos + len);
-				end = min_t(loff_t, end, PAGE_CACHE_SIZE);
+				end = min_t(loff_t, end, PAGE_SIZE);
 				if (statret < end)
 					zero_user_segment(page, statret, end);
 				ret = copy_page_to_iter(page,
@@ -1463,21 +1463,21 @@ static inline void ceph_zero_partial_page(
 	struct inode *inode, loff_t offset, unsigned size)
 {
 	struct page *page;
-	pgoff_t index = offset >> PAGE_CACHE_SHIFT;
+	pgoff_t index = offset >> PAGE_SHIFT;
 
 	page = find_lock_page(inode->i_mapping, index);
 	if (page) {
 		wait_on_page_writeback(page);
-		zero_user(page, offset & (PAGE_CACHE_SIZE - 1), size);
+		zero_user(page, offset & (PAGE_SIZE - 1), size);
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 	}
 }
 
 static void ceph_zero_pagecache_range(struct inode *inode, loff_t offset,
 				      loff_t length)
 {
-	loff_t nearly = round_up(offset, PAGE_CACHE_SIZE);
+	loff_t nearly = round_up(offset, PAGE_SIZE);
 	if (offset < nearly) {
 		loff_t size = nearly - offset;
 		if (length < size)
@@ -1486,8 +1486,8 @@ static void ceph_zero_pagecache_range(struct inode *inode, loff_t offset,
 		offset += size;
 		length -= size;
 	}
-	if (length >= PAGE_CACHE_SIZE) {
-		loff_t size = round_down(length, PAGE_CACHE_SIZE);
+	if (length >= PAGE_SIZE) {
+		loff_t size = round_down(length, PAGE_SIZE);
 		truncate_pagecache_range(inode, offset, offset + size - 1);
 		offset += size;
 		length -= size;