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>

3 files changed, 20 insertions, 20 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 1831f6353622..a5502898ea33 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -269,7 +269,7 @@ static void _ceph_msgr_exit(void)
 	}
 
 	BUG_ON(zero_page == NULL);
-	page_cache_release(zero_page);
+	put_page(zero_page);
 	zero_page = NULL;
 
 	ceph_msgr_slab_exit();
@@ -282,7 +282,7 @@ int ceph_msgr_init(void)
 
 	BUG_ON(zero_page != NULL);
 	zero_page = ZERO_PAGE(0);
-	page_cache_get(zero_page);
+	get_page(zero_page);
 
 	/*
 	 * The number of active work items is limited by the number of
@@ -1602,7 +1602,7 @@ static int write_partial_skip(struct ceph_connection *con)
 
 	dout("%s %p %d left\n", __func__, con, con->out_skip);
 	while (con->out_skip > 0) {
-		size_t size = min(con->out_skip, (int) PAGE_CACHE_SIZE);
+		size_t size = min(con->out_skip, (int) PAGE_SIZE);
 
 		ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, true);
 		if (ret <= 0)
diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c
index c7c220a736e5..6864007e64fc 100644
--- a/net/ceph/pagelist.c
+++ b/net/ceph/pagelist.c
@@ -56,7 +56,7 @@ int ceph_pagelist_append(struct ceph_pagelist *pl, const void *buf, size_t len)
 		size_t bit = pl->room;
 		int ret;
 
-		memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK),
+		memcpy(pl->mapped_tail + (pl->length & ~PAGE_MASK),
 		       buf, bit);
 		pl->length += bit;
 		pl->room -= bit;
@@ -67,7 +67,7 @@ int ceph_pagelist_append(struct ceph_pagelist *pl, const void *buf, size_t len)
 			return ret;
 	}
 
-	memcpy(pl->mapped_tail + (pl->length & ~PAGE_CACHE_MASK), buf, len);
+	memcpy(pl->mapped_tail + (pl->length & ~PAGE_MASK), buf, len);
 	pl->length += len;
 	pl->room -= len;
 	return 0;
diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
index 10297f7a89ba..00d2601407c5 100644
--- a/net/ceph/pagevec.c
+++ b/net/ceph/pagevec.c
@@ -95,19 +95,19 @@ int ceph_copy_user_to_page_vector(struct page **pages,
 					 loff_t off, size_t len)
 {
 	int i = 0;
-	int po = off & ~PAGE_CACHE_MASK;
+	int po = off & ~PAGE_MASK;
 	int left = len;
 	int l, bad;
 
 	while (left > 0) {
-		l = min_t(int, PAGE_CACHE_SIZE-po, left);
+		l = min_t(int, PAGE_SIZE-po, left);
 		bad = copy_from_user(page_address(pages[i]) + po, data, l);
 		if (bad == l)
 			return -EFAULT;
 		data += l - bad;
 		left -= l - bad;
 		po += l - bad;
-		if (po == PAGE_CACHE_SIZE) {
+		if (po == PAGE_SIZE) {
 			po = 0;
 			i++;
 		}
@@ -121,17 +121,17 @@ void ceph_copy_to_page_vector(struct page **pages,
 				    loff_t off, size_t len)
 {
 	int i = 0;
-	size_t po = off & ~PAGE_CACHE_MASK;
+	size_t po = off & ~PAGE_MASK;
 	size_t left = len;
 
 	while (left > 0) {
-		size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
+		size_t l = min_t(size_t, PAGE_SIZE-po, left);
 
 		memcpy(page_address(pages[i]) + po, data, l);
 		data += l;
 		left -= l;
 		po += l;
-		if (po == PAGE_CACHE_SIZE) {
+		if (po == PAGE_SIZE) {
 			po = 0;
 			i++;
 		}
@@ -144,17 +144,17 @@ void ceph_copy_from_page_vector(struct page **pages,
 				    loff_t off, size_t len)
 {
 	int i = 0;
-	size_t po = off & ~PAGE_CACHE_MASK;
+	size_t po = off & ~PAGE_MASK;
 	size_t left = len;
 
 	while (left > 0) {
-		size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
+		size_t l = min_t(size_t, PAGE_SIZE-po, left);
 
 		memcpy(data, page_address(pages[i]) + po, l);
 		data += l;
 		left -= l;
 		po += l;
-		if (po == PAGE_CACHE_SIZE) {
+		if (po == PAGE_SIZE) {
 			po = 0;
 			i++;
 		}
@@ -168,25 +168,25 @@ EXPORT_SYMBOL(ceph_copy_from_page_vector);
  */
 void ceph_zero_page_vector_range(int off, int len, struct page **pages)
 {
-	int i = off >> PAGE_CACHE_SHIFT;
+	int i = off >> PAGE_SHIFT;
 
-	off &= ~PAGE_CACHE_MASK;
+	off &= ~PAGE_MASK;
 
 	dout("zero_page_vector_page %u~%u\n", off, len);
 
 	/* leading partial page? */
 	if (off) {
-		int end = min((int)PAGE_CACHE_SIZE, off + len);
+		int end = min((int)PAGE_SIZE, off + len);
 		dout("zeroing %d %p head from %d\n", i, pages[i],
 		     (int)off);
 		zero_user_segment(pages[i], off, end);
 		len -= (end - off);
 		i++;
 	}
-	while (len >= PAGE_CACHE_SIZE) {
+	while (len >= PAGE_SIZE) {
 		dout("zeroing %d %p len=%d\n", i, pages[i], len);
-		zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
-		len -= PAGE_CACHE_SIZE;
+		zero_user_segment(pages[i], 0, PAGE_SIZE);
+		len -= PAGE_SIZE;
 		i++;
 	}
 	/* trailing partial page? */