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, 22 insertions, 22 deletions

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index aa016e4b8bec..1bbbee945f46 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -101,7 +101,7 @@ static int gfs2_writepage_common(struct page *page,
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	loff_t i_size = i_size_read(inode);
-	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	pgoff_t end_index = i_size >> PAGE_SHIFT;
 	unsigned offset;
 
 	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
@@ -109,9 +109,9 @@ static int gfs2_writepage_common(struct page *page,
 	if (current->journal_info)
 		goto redirty;
 	/* Is the page fully outside i_size? (truncate in progress) */
-	offset = i_size & (PAGE_CACHE_SIZE-1);
+	offset = i_size & (PAGE_SIZE-1);
 	if (page->index > end_index || (page->index == end_index && !offset)) {
-		page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE);
+		page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
 		goto out;
 	}
 	return 1;
@@ -238,7 +238,7 @@ static int gfs2_write_jdata_pagevec(struct address_space *mapping,
 {
 	struct inode *inode = mapping->host;
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
-	unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
+	unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
 	int i;
 	int ret;
 
@@ -366,8 +366,8 @@ static int gfs2_write_cache_jdata(struct address_space *mapping,
 			cycled = 0;
 		end = -1;
 	} else {
-		index = wbc->range_start >> PAGE_CACHE_SHIFT;
-		end = wbc->range_end >> PAGE_CACHE_SHIFT;
+		index = wbc->range_start >> PAGE_SHIFT;
+		end = wbc->range_end >> PAGE_SHIFT;
 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 			range_whole = 1;
 		cycled = 1; /* ignore range_cyclic tests */
@@ -458,7 +458,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 	 * so we need to supply one here. It doesn't happen often.
 	 */
 	if (unlikely(page->index)) {
-		zero_user(page, 0, PAGE_CACHE_SIZE);
+		zero_user(page, 0, PAGE_SIZE);
 		SetPageUptodate(page);
 		return 0;
 	}
@@ -471,7 +471,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 	if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
 		dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
 	memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
-	memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
+	memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
 	kunmap_atomic(kaddr);
 	flush_dcache_page(page);
 	brelse(dibh);
@@ -560,8 +560,8 @@ int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
                        unsigned size)
 {
 	struct address_space *mapping = ip->i_inode.i_mapping;
-	unsigned long index = *pos / PAGE_CACHE_SIZE;
-	unsigned offset = *pos & (PAGE_CACHE_SIZE - 1);
+	unsigned long index = *pos / PAGE_SIZE;
+	unsigned offset = *pos & (PAGE_SIZE - 1);
 	unsigned copied = 0;
 	unsigned amt;
 	struct page *page;
@@ -569,15 +569,15 @@ int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
 
 	do {
 		amt = size - copied;
-		if (offset + size > PAGE_CACHE_SIZE)
-			amt = PAGE_CACHE_SIZE - offset;
+		if (offset + size > PAGE_SIZE)
+			amt = PAGE_SIZE - offset;
 		page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
 		if (IS_ERR(page))
 			return PTR_ERR(page);
 		p = kmap_atomic(page);
 		memcpy(buf + copied, p + offset, amt);
 		kunmap_atomic(p);
-		page_cache_release(page);
+		put_page(page);
 		copied += amt;
 		index++;
 		offset = 0;
@@ -651,8 +651,8 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping,
 	unsigned requested = 0;
 	int alloc_required;
 	int error = 0;
-	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
-	unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+	pgoff_t index = pos >> PAGE_SHIFT;
+	unsigned from = pos & (PAGE_SIZE - 1);
 	struct page *page;
 
 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
@@ -697,7 +697,7 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping,
 		rblocks += gfs2_rg_blocks(ip, requested);
 
 	error = gfs2_trans_begin(sdp, rblocks,
-				 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
+				 PAGE_SIZE/sdp->sd_sb.sb_bsize);
 	if (error)
 		goto out_trans_fail;
 
@@ -727,7 +727,7 @@ out:
 		return 0;
 
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 
 	gfs2_trans_end(sdp);
 	if (pos + len > ip->i_inode.i_size)
@@ -827,7 +827,7 @@ static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
 	if (!PageUptodate(page))
 		SetPageUptodate(page);
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 
 	if (copied) {
 		if (inode->i_size < to)
@@ -877,7 +877,7 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 	struct buffer_head *dibh;
-	unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
+	unsigned int from = pos & (PAGE_SIZE - 1);
 	unsigned int to = from + len;
 	int ret;
 	struct gfs2_trans *tr = current->journal_info;
@@ -888,7 +888,7 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
 	ret = gfs2_meta_inode_buffer(ip, &dibh);
 	if (unlikely(ret)) {
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		goto failed;
 	}
 
@@ -992,7 +992,7 @@ static void gfs2_invalidatepage(struct page *page, unsigned int offset,
 {
 	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
 	unsigned int stop = offset + length;
-	int partial_page = (offset || length < PAGE_CACHE_SIZE);
+	int partial_page = (offset || length < PAGE_SIZE);
 	struct buffer_head *bh, *head;
 	unsigned long pos = 0;
 
@@ -1082,7 +1082,7 @@ static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	 * the first place, mapping->nr_pages will always be zero.
 	 */
 	if (mapping->nrpages) {
-		loff_t lstart = offset & ~(PAGE_CACHE_SIZE - 1);
+		loff_t lstart = offset & ~(PAGE_SIZE - 1);
 		loff_t len = iov_iter_count(iter);
 		loff_t end = PAGE_ALIGN(offset + len) - 1;