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, 20 insertions, 20 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 15a09cb156ce..cf31a60c6284 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -414,11 +414,11 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
 	size_t copied = 0;
 	size_t total_copied = 0;
 	int pg = 0;
-	int offset = pos & (PAGE_CACHE_SIZE - 1);
+	int offset = pos & (PAGE_SIZE - 1);
 
 	while (write_bytes > 0) {
 		size_t count = min_t(size_t,
-				     PAGE_CACHE_SIZE - offset, write_bytes);
+				     PAGE_SIZE - offset, write_bytes);
 		struct page *page = prepared_pages[pg];
 		/*
 		 * Copy data from userspace to the current page
@@ -448,7 +448,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
 		if (unlikely(copied == 0))
 			break;
 
-		if (copied < PAGE_CACHE_SIZE - offset) {
+		if (copied < PAGE_SIZE - offset) {
 			offset += copied;
 		} else {
 			pg++;
@@ -473,7 +473,7 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
 		 */
 		ClearPageChecked(pages[i]);
 		unlock_page(pages[i]);
-		page_cache_release(pages[i]);
+		put_page(pages[i]);
 	}
 }
 
@@ -1297,7 +1297,7 @@ static int prepare_uptodate_page(struct inode *inode,
 {
 	int ret = 0;
 
-	if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
+	if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
 	    !PageUptodate(page)) {
 		ret = btrfs_readpage(NULL, page);
 		if (ret)
@@ -1323,7 +1323,7 @@ static noinline int prepare_pages(struct inode *inode, struct page **pages,
 				  size_t write_bytes, bool force_uptodate)
 {
 	int i;
-	unsigned long index = pos >> PAGE_CACHE_SHIFT;
+	unsigned long index = pos >> PAGE_SHIFT;
 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 	int err = 0;
 	int faili;
@@ -1345,7 +1345,7 @@ again:
 			err = prepare_uptodate_page(inode, pages[i],
 						    pos + write_bytes, false);
 		if (err) {
-			page_cache_release(pages[i]);
+			put_page(pages[i]);
 			if (err == -EAGAIN) {
 				err = 0;
 				goto again;
@@ -1360,7 +1360,7 @@ again:
 fail:
 	while (faili >= 0) {
 		unlock_page(pages[faili]);
-		page_cache_release(pages[faili]);
+		put_page(pages[faili]);
 		faili--;
 	}
 	return err;
@@ -1408,7 +1408,7 @@ lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
 					     cached_state, GFP_NOFS);
 			for (i = 0; i < num_pages; i++) {
 				unlock_page(pages[i]);
-				page_cache_release(pages[i]);
+				put_page(pages[i]);
 			}
 			btrfs_start_ordered_extent(inode, ordered, 1);
 			btrfs_put_ordered_extent(ordered);
@@ -1497,8 +1497,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 	bool force_page_uptodate = false;
 	bool need_unlock;
 
-	nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_CACHE_SIZE),
-			PAGE_CACHE_SIZE / (sizeof(struct page *)));
+	nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
+			PAGE_SIZE / (sizeof(struct page *)));
 	nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
 	nrptrs = max(nrptrs, 8);
 	pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
@@ -1506,13 +1506,13 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 		return -ENOMEM;
 
 	while (iov_iter_count(i) > 0) {
-		size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+		size_t offset = pos & (PAGE_SIZE - 1);
 		size_t sector_offset;
 		size_t write_bytes = min(iov_iter_count(i),
-					 nrptrs * (size_t)PAGE_CACHE_SIZE -
+					 nrptrs * (size_t)PAGE_SIZE -
 					 offset);
 		size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
-						PAGE_CACHE_SIZE);
+						PAGE_SIZE);
 		size_t reserve_bytes;
 		size_t dirty_pages;
 		size_t copied;
@@ -1547,7 +1547,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 			 * write_bytes, so scale down.
 			 */
 			num_pages = DIV_ROUND_UP(write_bytes + offset,
-						 PAGE_CACHE_SIZE);
+						 PAGE_SIZE);
 			reserve_bytes = round_up(write_bytes + sector_offset,
 					root->sectorsize);
 			goto reserve_metadata;
@@ -1609,7 +1609,7 @@ again:
 		} else {
 			force_page_uptodate = false;
 			dirty_pages = DIV_ROUND_UP(copied + offset,
-						   PAGE_CACHE_SIZE);
+						   PAGE_SIZE);
 		}
 
 		/*
@@ -1641,7 +1641,7 @@ again:
 				u64 __pos;
 
 				__pos = round_down(pos, root->sectorsize) +
-					(dirty_pages << PAGE_CACHE_SHIFT);
+					(dirty_pages << PAGE_SHIFT);
 				btrfs_delalloc_release_space(inode, __pos,
 							     release_bytes);
 			}
@@ -1682,7 +1682,7 @@ again:
 		cond_resched();
 
 		balance_dirty_pages_ratelimited(inode->i_mapping);
-		if (dirty_pages < (root->nodesize >> PAGE_CACHE_SHIFT) + 1)
+		if (dirty_pages < (root->nodesize >> PAGE_SHIFT) + 1)
 			btrfs_btree_balance_dirty(root);
 
 		pos += copied;
@@ -1738,8 +1738,8 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb,
 		goto out;
 	written += written_buffered;
 	iocb->ki_pos = pos + written_buffered;
-	invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
-				 endbyte >> PAGE_CACHE_SHIFT);
+	invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
+				 endbyte >> PAGE_SHIFT);
 out:
 	return written ? written : err;
 }