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>

7 files changed, 38 insertions, 38 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 8c6bc795f060..15612ffa8d57 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1728,8 +1728,8 @@ alloc_enc_pages(struct rpc_rqst *rqstp)
 		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 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 	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 d94a8e1e9f05..045e11ecd332 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -465,7 +465,7 @@ encryptor(struct scatterlist *sg, void *data)
 	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 765088e4ad84..a737c2da0837 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -79,9 +79,9 @@ gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
 		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 008c25d1b9f9..553bf95f7003 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -881,7 +881,7 @@ static ssize_t cache_downcall(struct address_space *mapping,
 	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 @@ static ssize_t cache_downcall(struct address_space *mapping,
 	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 31789ef3e614..fc48eca21fd2 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -1390,8 +1390,8 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
 	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 2df87f78e518..de70c78025d7 100644
--- a/net/sunrpc/socklib.c
+++ b/net/sunrpc/socklib.c
@@ -96,8 +96,8 @@ ssize_t xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, struct
 	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 @@ ssize_t xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, struct
 			}
 		}
 
-		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 4439ac4c1b53..1e6aba0501a1 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -181,20 +181,20 @@ _shift_data_right_pages(struct page **pages, size_t pgto_base,
 	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 @@ _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
 	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 @@ _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
 			break;
 
 		pgbase += copy;
-		if (pgbase == PAGE_CACHE_SIZE) {
+		if (pgbase == PAGE_SIZE) {
 			flush_dcache_page(*pgto);
 			pgbase = 0;
 			pgto++;
@@ -280,11 +280,11 @@ _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
 	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 @@ _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
 		kunmap_atomic(vfrom);
 
 		pgbase += copy;
-		if (pgbase == PAGE_CACHE_SIZE) {
+		if (pgbase == PAGE_SIZE) {
 			pgbase = 0;
 			pgfrom++;
 		}
@@ -1038,8 +1038,8 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
 	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 @@ xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
 		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 @@ xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
 			}
 
 			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 @@ xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
 		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 @@ xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
 			page_len -= thislen;
 			i++;
 			page_offset = 0;
-			thislen = PAGE_CACHE_SIZE;
+			thislen = PAGE_SIZE;
 		} while (page_len != 0);
 		offset = 0;
 	}