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/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 8c6bc79..15612ff 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1728,8 +1728,8 @@
 		return 0;
 	}
 
-	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
-	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
+	first = snd_buf->page_base >> PAGE_SHIFT;
+	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
 	rqstp->rq_enc_pages_num = last - first + 1 + 1;
 	rqstp->rq_enc_pages
 		= kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
@@ -1775,10 +1775,10 @@
 	status = alloc_enc_pages(rqstp);
 	if (status)
 		return status;
-	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
+	first = snd_buf->page_base >> PAGE_SHIFT;
 	inpages = snd_buf->pages + first;
 	snd_buf->pages = rqstp->rq_enc_pages;
-	snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
+	snd_buf->page_base -= first << PAGE_SHIFT;
 	/*
 	 * Give the tail its own page, in case we need extra space in the
 	 * head when wrapping:
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index d94a8e1..045e11e 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -465,7 +465,7 @@
 	page_pos = desc->pos - outbuf->head[0].iov_len;
 	if (page_pos >= 0 && page_pos < outbuf->page_len) {
 		/* pages are not in place: */
-		int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
+		int i = (page_pos + outbuf->page_base) >> PAGE_SHIFT;
 		in_page = desc->pages[i];
 	} else {
 		in_page = sg_page(sg);
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index 765088e4..a737c2d 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -79,9 +79,9 @@
 		len -= buf->head[0].iov_len;
 	if (len <= buf->page_len) {
 		unsigned int last = (buf->page_base + len - 1)
-					>>PAGE_CACHE_SHIFT;
+					>>PAGE_SHIFT;
 		unsigned int offset = (buf->page_base + len - 1)
-					& (PAGE_CACHE_SIZE - 1);
+					& (PAGE_SIZE - 1);
 		ptr = kmap_atomic(buf->pages[last]);
 		pad = *(ptr + offset);
 		kunmap_atomic(ptr);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 008c25d..553bf95 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -881,7 +881,7 @@
 	char *kaddr;
 	ssize_t ret = -ENOMEM;
 
-	if (count >= PAGE_CACHE_SIZE)
+	if (count >= PAGE_SIZE)
 		goto out_slow;
 
 	page = find_or_create_page(mapping, 0, GFP_KERNEL);
@@ -892,7 +892,7 @@
 	ret = cache_do_downcall(kaddr, buf, count, cd);
 	kunmap(page);
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return ret;
 out_slow:
 	return cache_slow_downcall(buf, count, cd);
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 31789ef..fc48eca 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -1390,8 +1390,8 @@
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	int err;
 
-	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 = RPCAUTH_GSSMAGIC;
 	sb->s_op = &s_ops;
 	sb->s_d_op = &simple_dentry_operations;
diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
index 2df87f7..de70c78 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -96,8 +96,8 @@
 	if (base || xdr->page_base) {
 		pglen -= base;
 		base += xdr->page_base;
-		ppage += base >> PAGE_CACHE_SHIFT;
-		base &= ~PAGE_CACHE_MASK;
+		ppage += base >> PAGE_SHIFT;
+		base &= ~PAGE_MASK;
 	}
 	do {
 		char *kaddr;
@@ -113,7 +113,7 @@
 			}
 		}
 
-		len = PAGE_CACHE_SIZE;
+		len = PAGE_SIZE;
 		kaddr = kmap_atomic(*ppage);
 		if (base) {
 			len -= base;
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 4439ac4..1e6aba0 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -181,20 +181,20 @@
 	pgto_base += len;
 	pgfrom_base += len;
 
-	pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT);
-	pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT);
+	pgto = pages + (pgto_base >> PAGE_SHIFT);
+	pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
 
-	pgto_base &= ~PAGE_CACHE_MASK;
-	pgfrom_base &= ~PAGE_CACHE_MASK;
+	pgto_base &= ~PAGE_MASK;
+	pgfrom_base &= ~PAGE_MASK;
 
 	do {
 		/* Are any pointers crossing a page boundary? */
 		if (pgto_base == 0) {
-			pgto_base = PAGE_CACHE_SIZE;
+			pgto_base = PAGE_SIZE;
 			pgto--;
 		}
 		if (pgfrom_base == 0) {
-			pgfrom_base = PAGE_CACHE_SIZE;
+			pgfrom_base = PAGE_SIZE;
 			pgfrom--;
 		}
 
@@ -236,11 +236,11 @@
 	char *vto;
 	size_t copy;
 
-	pgto = pages + (pgbase >> PAGE_CACHE_SHIFT);
-	pgbase &= ~PAGE_CACHE_MASK;
+	pgto = pages + (pgbase >> PAGE_SHIFT);
+	pgbase &= ~PAGE_MASK;
 
 	for (;;) {
-		copy = PAGE_CACHE_SIZE - pgbase;
+		copy = PAGE_SIZE - pgbase;
 		if (copy > len)
 			copy = len;
 
@@ -253,7 +253,7 @@
 			break;
 
 		pgbase += copy;
-		if (pgbase == PAGE_CACHE_SIZE) {
+		if (pgbase == PAGE_SIZE) {
 			flush_dcache_page(*pgto);
 			pgbase = 0;
 			pgto++;
@@ -280,11 +280,11 @@
 	char *vfrom;
 	size_t copy;
 
-	pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT);
-	pgbase &= ~PAGE_CACHE_MASK;
+	pgfrom = pages + (pgbase >> PAGE_SHIFT);
+	pgbase &= ~PAGE_MASK;
 
 	do {
-		copy = PAGE_CACHE_SIZE - pgbase;
+		copy = PAGE_SIZE - pgbase;
 		if (copy > len)
 			copy = len;
 
@@ -293,7 +293,7 @@
 		kunmap_atomic(vfrom);
 
 		pgbase += copy;
-		if (pgbase == PAGE_CACHE_SIZE) {
+		if (pgbase == PAGE_SIZE) {
 			pgbase = 0;
 			pgfrom++;
 		}
@@ -1038,8 +1038,8 @@
 	if (base < buf->page_len) {
 		subbuf->page_len = min(buf->page_len - base, len);
 		base += buf->page_base;
-		subbuf->page_base = base & ~PAGE_CACHE_MASK;
-		subbuf->pages = &buf->pages[base >> PAGE_CACHE_SHIFT];
+		subbuf->page_base = base & ~PAGE_MASK;
+		subbuf->pages = &buf->pages[base >> PAGE_SHIFT];
 		len -= subbuf->page_len;
 		base = 0;
 	} else {
@@ -1297,9 +1297,9 @@
 		todo -= avail_here;
 
 		base += buf->page_base;
-		ppages = buf->pages + (base >> PAGE_CACHE_SHIFT);
-		base &= ~PAGE_CACHE_MASK;
-		avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base,
+		ppages = buf->pages + (base >> PAGE_SHIFT);
+		base &= ~PAGE_MASK;
+		avail_page = min_t(unsigned int, PAGE_SIZE - base,
 					avail_here);
 		c = kmap(*ppages) + base;
 
@@ -1383,7 +1383,7 @@
 			}
 
 			avail_page = min(avail_here,
-				 (unsigned int) PAGE_CACHE_SIZE);
+				 (unsigned int) PAGE_SIZE);
 		}
 		base = buf->page_len;  /* align to start of tail */
 	}
@@ -1479,9 +1479,9 @@
 		if (page_len > len)
 			page_len = len;
 		len -= page_len;
-		page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
-		i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
-		thislen = PAGE_CACHE_SIZE - page_offset;
+		page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1);
+		i = (offset + buf->page_base) >> PAGE_SHIFT;
+		thislen = PAGE_SIZE - page_offset;
 		do {
 			if (thislen > page_len)
 				thislen = page_len;
@@ -1492,7 +1492,7 @@
 			page_len -= thislen;
 			i++;
 			page_offset = 0;
-			thislen = PAGE_CACHE_SIZE;
+			thislen = PAGE_SIZE;
 		} while (page_len != 0);
 		offset = 0;
 	}