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/fs/gfs2/aops.c b/fs/gfs2/aops.c
index aa016e4..1bbbee9 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -101,7 +101,7 @@
 	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 @@
 	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 @@
 {
 	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 @@
 			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 @@
 	 * 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 @@
 	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 @@
                        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 @@
 
 	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 @@
 	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 @@
 		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 @@
 		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 @@
 	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 @@
 	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 @@
 	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 @@
 {
 	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 @@
 	 * 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;
 
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 0860f0b..24ce1cd 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -75,7 +75,7 @@
 			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(page);
 
 		SetPageUptodate(page);
@@ -98,7 +98,7 @@
 
 	if (release) {
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 	}
 
 	return 0;
@@ -932,8 +932,8 @@
 {
 	struct inode *inode = mapping->host;
 	struct gfs2_inode *ip = GFS2_I(inode);
-	unsigned long index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	unsigned long index = from >> PAGE_SHIFT;
+	unsigned offset = from & (PAGE_SIZE-1);
 	unsigned blocksize, iblock, length, pos;
 	struct buffer_head *bh;
 	struct page *page;
@@ -945,7 +945,7 @@
 
 	blocksize = inode->i_sb->s_blocksize;
 	length = blocksize - (offset & (blocksize - 1));
-	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+	iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
 
 	if (!page_has_buffers(page))
 		create_empty_buffers(page, blocksize, 0);
@@ -989,7 +989,7 @@
 	mark_buffer_dirty(bh);
 unlock:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return err;
 }
 
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index c9384f9..208efc7 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -354,8 +354,8 @@
 {
 	struct inode *inode = page->mapping->host;
 	struct buffer_head bh;
-	unsigned long size = PAGE_CACHE_SIZE;
-	u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	unsigned long size = PAGE_SIZE;
+	u64 lblock = page->index << (PAGE_SHIFT - inode->i_blkbits);
 
 	do {
 		bh.b_state = 0;
@@ -386,7 +386,7 @@
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	struct gfs2_alloc_parms ap = { .aflags = 0, };
 	unsigned long last_index;
-	u64 pos = page->index << PAGE_CACHE_SHIFT;
+	u64 pos = page->index << PAGE_SHIFT;
 	unsigned int data_blocks, ind_blocks, rblocks;
 	struct gfs2_holder gh;
 	loff_t size;
@@ -401,7 +401,7 @@
 	if (ret)
 		goto out;
 
-	gfs2_size_hint(vma->vm_file, pos, PAGE_CACHE_SIZE);
+	gfs2_size_hint(vma->vm_file, pos, PAGE_SIZE);
 
 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 	ret = gfs2_glock_nq(&gh);
@@ -411,7 +411,7 @@
 	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
 	set_bit(GIF_SW_PAGED, &ip->i_flags);
 
-	if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE)) {
+	if (!gfs2_write_alloc_required(ip, pos, PAGE_SIZE)) {
 		lock_page(page);
 		if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
 			ret = -EAGAIN;
@@ -424,7 +424,7 @@
 	if (ret)
 		goto out_unlock;
 
-	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
+	gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
 	ap.target = data_blocks + ind_blocks;
 	ret = gfs2_quota_lock_check(ip, &ap);
 	if (ret)
@@ -447,7 +447,7 @@
 	lock_page(page);
 	ret = -EINVAL;
 	size = i_size_read(inode);
-	last_index = (size - 1) >> PAGE_CACHE_SHIFT;
+	last_index = (size - 1) >> PAGE_SHIFT;
 	/* Check page index against inode size */
 	if (size == 0 || (page->index > last_index))
 		goto out_trans_end;
@@ -873,7 +873,7 @@
 			rblocks += data_blocks ? data_blocks : 1;
 
 		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;
 
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index e137d96..0448524 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -124,7 +124,7 @@
 	if (mapping == NULL)
 		mapping = &sdp->sd_aspace;
 
-	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
+	shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 	index = blkno >> shift;             /* convert block to page */
 	bufnum = blkno - (index << shift);  /* block buf index within page */
 
@@ -154,7 +154,7 @@
 		map_bh(bh, sdp->sd_vfs, blkno);
 
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 
 	return bh;
 }
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index a398913..ce7d69a 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -701,7 +701,7 @@
 	unsigned to_write = bytes, pg_off = off;
 	int done = 0;
 
-	blk = index << (PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift);
+	blk = index << (PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift);
 	boff = off % bsize;
 
 	page = find_or_create_page(mapping, index, GFP_NOFS);
@@ -753,13 +753,13 @@
 	flush_dcache_page(page);
 	kunmap_atomic(kaddr);
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 
 	return 0;
 
 unlock_out:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return -EIO;
 }
 
@@ -773,13 +773,13 @@
 
 	nbytes = sizeof(struct gfs2_quota);
 
-	pg_beg = loc >> PAGE_CACHE_SHIFT;
-	pg_off = loc % PAGE_CACHE_SIZE;
+	pg_beg = loc >> PAGE_SHIFT;
+	pg_off = loc % PAGE_SIZE;
 
 	/* If the quota straddles a page boundary, split the write in two */
-	if ((pg_off + nbytes) > PAGE_CACHE_SIZE) {
+	if ((pg_off + nbytes) > PAGE_SIZE) {
 		pg_oflow = 1;
-		overflow = (pg_off + nbytes) - PAGE_CACHE_SIZE;
+		overflow = (pg_off + nbytes) - PAGE_SIZE;
 	}
 
 	ptr = qp;
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 07c0265..99a0bda 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -918,9 +918,8 @@
 		goto fail;
 
 	rgd->rd_gl->gl_object = rgd;
-	rgd->rd_gl->gl_vm.start = (rgd->rd_addr * bsize) & PAGE_CACHE_MASK;
-	rgd->rd_gl->gl_vm.end = PAGE_CACHE_ALIGN((rgd->rd_addr +
-						  rgd->rd_length) * bsize) - 1;
+	rgd->rd_gl->gl_vm.start = (rgd->rd_addr * bsize) & PAGE_MASK;
+	rgd->rd_gl->gl_vm.end = PAGE_ALIGN((rgd->rd_addr + rgd->rd_length) * bsize) - 1;
 	rgd->rd_rgl = (struct gfs2_rgrp_lvb *)rgd->rd_gl->gl_lksb.sb_lvbptr;
 	rgd->rd_flags &= ~(GFS2_RDF_UPTODATE | GFS2_RDF_PREFERRED);
 	if (rgd->rd_data > sdp->sd_max_rg_data)