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, 52 insertions, 52 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 41a5688ffdfe..2aaba58b4856 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -194,7 +194,7 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		while (compressed_size > 0) {
 			cpage = compressed_pages[i];
 			cur_size = min_t(unsigned long, compressed_size,
-				       PAGE_CACHE_SIZE);
+				       PAGE_SIZE);
 
 			kaddr = kmap_atomic(cpage);
 			write_extent_buffer(leaf, kaddr, ptr, cur_size);
@@ -208,13 +208,13 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 						  compress_type);
 	} else {
 		page = find_get_page(inode->i_mapping,
-				     start >> PAGE_CACHE_SHIFT);
+				     start >> PAGE_SHIFT);
 		btrfs_set_file_extent_compression(leaf, ei, 0);
 		kaddr = kmap_atomic(page);
-		offset = start & (PAGE_CACHE_SIZE - 1);
+		offset = start & (PAGE_SIZE - 1);
 		write_extent_buffer(leaf, kaddr + offset, ptr, size);
 		kunmap_atomic(kaddr);
-		page_cache_release(page);
+		put_page(page);
 	}
 	btrfs_mark_buffer_dirty(leaf);
 	btrfs_release_path(path);
@@ -322,7 +322,7 @@ out:
 	 * And at reserve time, it's always aligned to page size, so
 	 * just free one page here.
 	 */
-	btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE);
+	btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
 	btrfs_free_path(path);
 	btrfs_end_transaction(trans, root);
 	return ret;
@@ -435,8 +435,8 @@ static noinline void compress_file_range(struct inode *inode,
 	actual_end = min_t(u64, isize, end + 1);
 again:
 	will_compress = 0;
-	nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
-	nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_CACHE_SIZE);
+	nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
+	nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
 
 	/*
 	 * we don't want to send crud past the end of i_size through
@@ -514,7 +514,7 @@ again:
 
 		if (!ret) {
 			unsigned long offset = total_compressed &
-				(PAGE_CACHE_SIZE - 1);
+				(PAGE_SIZE - 1);
 			struct page *page = pages[nr_pages_ret - 1];
 			char *kaddr;
 
@@ -524,7 +524,7 @@ again:
 			if (offset) {
 				kaddr = kmap_atomic(page);
 				memset(kaddr + offset, 0,
-				       PAGE_CACHE_SIZE - offset);
+				       PAGE_SIZE - offset);
 				kunmap_atomic(kaddr);
 			}
 			will_compress = 1;
@@ -580,7 +580,7 @@ cont:
 		 * one last check to make sure the compression is really a
 		 * win, compare the page count read with the blocks on disk
 		 */
-		total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
+		total_in = ALIGN(total_in, PAGE_SIZE);
 		if (total_compressed >= total_in) {
 			will_compress = 0;
 		} else {
@@ -594,7 +594,7 @@ cont:
 		 */
 		for (i = 0; i < nr_pages_ret; i++) {
 			WARN_ON(pages[i]->mapping);
-			page_cache_release(pages[i]);
+			put_page(pages[i]);
 		}
 		kfree(pages);
 		pages = NULL;
@@ -650,7 +650,7 @@ cleanup_and_bail_uncompressed:
 free_pages_out:
 	for (i = 0; i < nr_pages_ret; i++) {
 		WARN_ON(pages[i]->mapping);
-		page_cache_release(pages[i]);
+		put_page(pages[i]);
 	}
 	kfree(pages);
 }
@@ -664,7 +664,7 @@ static void free_async_extent_pages(struct async_extent *async_extent)
 
 	for (i = 0; i < async_extent->nr_pages; i++) {
 		WARN_ON(async_extent->pages[i]->mapping);
-		page_cache_release(async_extent->pages[i]);
+		put_page(async_extent->pages[i]);
 	}
 	kfree(async_extent->pages);
 	async_extent->nr_pages = 0;
@@ -966,7 +966,7 @@ static noinline int cow_file_range(struct inode *inode,
 				     PAGE_END_WRITEBACK);
 
 			*nr_written = *nr_written +
-			     (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
+			     (end - start + PAGE_SIZE) / PAGE_SIZE;
 			*page_started = 1;
 			goto out;
 		} else if (ret < 0) {
@@ -1106,8 +1106,8 @@ static noinline void async_cow_submit(struct btrfs_work *work)
 	async_cow = container_of(work, struct async_cow, work);
 
 	root = async_cow->root;
-	nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
-		PAGE_CACHE_SHIFT;
+	nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
+		PAGE_SHIFT;
 
 	/*
 	 * atomic_sub_return implies a barrier for waitqueue_active
@@ -1164,8 +1164,8 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
 				async_cow_start, async_cow_submit,
 				async_cow_free);
 
-		nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
-			PAGE_CACHE_SHIFT;
+		nr_pages = (cur_end - start + PAGE_SIZE) >>
+			PAGE_SHIFT;
 		atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
 
 		btrfs_queue_work(root->fs_info->delalloc_workers,
@@ -1960,7 +1960,7 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
 			      struct extent_state **cached_state)
 {
-	WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
+	WARN_ON((end & (PAGE_SIZE - 1)) == 0);
 	return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
 				   cached_state, GFP_NOFS);
 }
@@ -1993,7 +1993,7 @@ again:
 
 	inode = page->mapping->host;
 	page_start = page_offset(page);
-	page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
+	page_end = page_offset(page) + PAGE_SIZE - 1;
 
 	lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
 			 &cached_state);
@@ -2003,7 +2003,7 @@ again:
 		goto out;
 
 	ordered = btrfs_lookup_ordered_range(inode, page_start,
-					PAGE_CACHE_SIZE);
+					PAGE_SIZE);
 	if (ordered) {
 		unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
 				     page_end, &cached_state, GFP_NOFS);
@@ -2014,7 +2014,7 @@ again:
 	}
 
 	ret = btrfs_delalloc_reserve_space(inode, page_start,
-					   PAGE_CACHE_SIZE);
+					   PAGE_SIZE);
 	if (ret) {
 		mapping_set_error(page->mapping, ret);
 		end_extent_writepage(page, ret, page_start, page_end);
@@ -2030,7 +2030,7 @@ out:
 			     &cached_state, GFP_NOFS);
 out_page:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	kfree(fixup);
 }
 
@@ -2063,7 +2063,7 @@ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
 		return -EAGAIN;
 
 	SetPageChecked(page);
-	page_cache_get(page);
+	get_page(page);
 	btrfs_init_work(&fixup->work, btrfs_fixup_helper,
 			btrfs_writepage_fixup_worker, NULL, NULL);
 	fixup->page = page;
@@ -4247,7 +4247,7 @@ static int truncate_inline_extent(struct inode *inode,
 
 	if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
 		loff_t offset = new_size;
-		loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE);
+		loff_t page_end = ALIGN(offset, PAGE_SIZE);
 
 		/*
 		 * Zero out the remaining of the last page of our inline extent,
@@ -4633,7 +4633,7 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
 	struct extent_state *cached_state = NULL;
 	char *kaddr;
 	u32 blocksize = root->sectorsize;
-	pgoff_t index = from >> PAGE_CACHE_SHIFT;
+	pgoff_t index = from >> PAGE_SHIFT;
 	unsigned offset = from & (blocksize - 1);
 	struct page *page;
 	gfp_t mask = btrfs_alloc_write_mask(mapping);
@@ -4668,7 +4668,7 @@ again:
 		lock_page(page);
 		if (page->mapping != mapping) {
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 			goto again;
 		}
 		if (!PageUptodate(page)) {
@@ -4686,7 +4686,7 @@ again:
 		unlock_extent_cached(io_tree, block_start, block_end,
 				     &cached_state, GFP_NOFS);
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		btrfs_start_ordered_extent(inode, ordered, 1);
 		btrfs_put_ordered_extent(ordered);
 		goto again;
@@ -4728,7 +4728,7 @@ out_unlock:
 		btrfs_delalloc_release_space(inode, block_start,
 					     blocksize);
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 out:
 	return ret;
 }
@@ -6717,7 +6717,7 @@ static noinline int uncompress_inline(struct btrfs_path *path,
 
 	read_extent_buffer(leaf, tmp, ptr, inline_size);
 
-	max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
+	max_size = min_t(unsigned long, PAGE_SIZE, max_size);
 	ret = btrfs_decompress(compress_type, tmp, page,
 			       extent_offset, inline_size, max_size);
 	kfree(tmp);
@@ -6879,8 +6879,8 @@ next:
 
 		size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
 		extent_offset = page_offset(page) + pg_offset - extent_start;
-		copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
-				size - extent_offset);
+		copy_size = min_t(u64, PAGE_SIZE - pg_offset,
+				  size - extent_offset);
 		em->start = extent_start + extent_offset;
 		em->len = ALIGN(copy_size, root->sectorsize);
 		em->orig_block_len = em->len;
@@ -6899,9 +6899,9 @@ next:
 				map = kmap(page);
 				read_extent_buffer(leaf, map + pg_offset, ptr,
 						   copy_size);
-				if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
+				if (pg_offset + copy_size < PAGE_SIZE) {
 					memset(map + pg_offset + copy_size, 0,
-					       PAGE_CACHE_SIZE - pg_offset -
+					       PAGE_SIZE - pg_offset -
 					       copy_size);
 				}
 				kunmap(page);
@@ -7336,12 +7336,12 @@ bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
 	int start_idx;
 	int end_idx;
 
-	start_idx = start >> PAGE_CACHE_SHIFT;
+	start_idx = start >> PAGE_SHIFT;
 
 	/*
 	 * end is the last byte in the last page.  end == start is legal
 	 */
-	end_idx = end >> PAGE_CACHE_SHIFT;
+	end_idx = end >> PAGE_SHIFT;
 
 	rcu_read_lock();
 
@@ -7382,7 +7382,7 @@ bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
 		 * include/linux/pagemap.h for details.
 		 */
 		if (unlikely(page != *pagep)) {
-			page_cache_release(page);
+			put_page(page);
 			page = NULL;
 		}
 	}
@@ -7390,7 +7390,7 @@ bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
 	if (page) {
 		if (page->index <= end_idx)
 			found = true;
-		page_cache_release(page);
+		put_page(page);
 	}
 
 	rcu_read_unlock();
@@ -8719,7 +8719,7 @@ static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
 	if (ret == 1) {
 		ClearPagePrivate(page);
 		set_page_private(page, 0);
-		page_cache_release(page);
+		put_page(page);
 	}
 	return ret;
 }
@@ -8739,7 +8739,7 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 	struct btrfs_ordered_extent *ordered;
 	struct extent_state *cached_state = NULL;
 	u64 page_start = page_offset(page);
-	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
+	u64 page_end = page_start + PAGE_SIZE - 1;
 	u64 start;
 	u64 end;
 	int inode_evicting = inode->i_state & I_FREEING;
@@ -8822,7 +8822,7 @@ again:
 	 * 2) Not written to disk
 	 *    This means the reserved space should be freed here.
 	 */
-	btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
+	btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
 	if (!inode_evicting) {
 		clear_extent_bit(tree, page_start, page_end,
 				 EXTENT_LOCKED | EXTENT_DIRTY |
@@ -8837,7 +8837,7 @@ again:
 	if (PagePrivate(page)) {
 		ClearPagePrivate(page);
 		set_page_private(page, 0);
-		page_cache_release(page);
+		put_page(page);
 	}
 }
 
@@ -8874,11 +8874,11 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	u64 page_end;
 	u64 end;
 
-	reserved_space = PAGE_CACHE_SIZE;
+	reserved_space = PAGE_SIZE;
 
 	sb_start_pagefault(inode->i_sb);
 	page_start = page_offset(page);
-	page_end = page_start + PAGE_CACHE_SIZE - 1;
+	page_end = page_start + PAGE_SIZE - 1;
 	end = page_end;
 
 	/*
@@ -8934,15 +8934,15 @@ again:
 		goto again;
 	}
 
-	if (page->index == ((size - 1) >> PAGE_CACHE_SHIFT)) {
+	if (page->index == ((size - 1) >> PAGE_SHIFT)) {
 		reserved_space = round_up(size - page_start, root->sectorsize);
-		if (reserved_space < PAGE_CACHE_SIZE) {
+		if (reserved_space < PAGE_SIZE) {
 			end = page_start + reserved_space - 1;
 			spin_lock(&BTRFS_I(inode)->lock);
 			BTRFS_I(inode)->outstanding_extents++;
 			spin_unlock(&BTRFS_I(inode)->lock);
 			btrfs_delalloc_release_space(inode, page_start,
-						PAGE_CACHE_SIZE - reserved_space);
+						PAGE_SIZE - reserved_space);
 		}
 	}
 
@@ -8969,14 +8969,14 @@ again:
 	ret = 0;
 
 	/* page is wholly or partially inside EOF */
-	if (page_start + PAGE_CACHE_SIZE > size)
-		zero_start = size & ~PAGE_CACHE_MASK;
+	if (page_start + PAGE_SIZE > size)
+		zero_start = size & ~PAGE_MASK;
 	else
-		zero_start = PAGE_CACHE_SIZE;
+		zero_start = PAGE_SIZE;
 
-	if (zero_start != PAGE_CACHE_SIZE) {
+	if (zero_start != PAGE_SIZE) {
 		kaddr = kmap(page);
-		memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
+		memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
 		flush_dcache_page(page);
 		kunmap(page);
 	}