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, 18 insertions, 18 deletions

diff --git a/fs/isofs/compress.c b/fs/isofs/compress.c
index f311bf084015..2e4e834d1a98 100644
--- a/fs/isofs/compress.c
+++ b/fs/isofs/compress.c
@@ -26,7 +26,7 @@
 #include "zisofs.h"
 
 /* This should probably be global. */
-static char zisofs_sink_page[PAGE_CACHE_SIZE];
+static char zisofs_sink_page[PAGE_SIZE];
 
 /*
  * This contains the zlib memory allocation and the mutex for the
@@ -70,11 +70,11 @@ static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start,
 		for ( i = 0 ; i < pcount ; i++ ) {
 			if (!pages[i])
 				continue;
-			memset(page_address(pages[i]), 0, PAGE_CACHE_SIZE);
+			memset(page_address(pages[i]), 0, PAGE_SIZE);
 			flush_dcache_page(pages[i]);
 			SetPageUptodate(pages[i]);
 		}
-		return ((loff_t)pcount) << PAGE_CACHE_SHIFT;
+		return ((loff_t)pcount) << PAGE_SHIFT;
 	}
 
 	/* Because zlib is not thread-safe, do all the I/O at the top. */
@@ -121,11 +121,11 @@ static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start,
 			if (pages[curpage]) {
 				stream.next_out = page_address(pages[curpage])
 						+ poffset;
-				stream.avail_out = PAGE_CACHE_SIZE - poffset;
+				stream.avail_out = PAGE_SIZE - poffset;
 				poffset = 0;
 			} else {
 				stream.next_out = (void *)&zisofs_sink_page;
-				stream.avail_out = PAGE_CACHE_SIZE;
+				stream.avail_out = PAGE_SIZE;
 			}
 		}
 		if (!stream.avail_in) {
@@ -220,14 +220,14 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
 	 * pages with the data we have anyway...
 	 */
 	start_off = page_offset(pages[full_page]);
-	end_off = min_t(loff_t, start_off + PAGE_CACHE_SIZE, inode->i_size);
+	end_off = min_t(loff_t, start_off + PAGE_SIZE, inode->i_size);
 
 	cstart_block = start_off >> zisofs_block_shift;
 	cend_block = (end_off + (1 << zisofs_block_shift) - 1)
 			>> zisofs_block_shift;
 
-	WARN_ON(start_off - (full_page << PAGE_CACHE_SHIFT) !=
-		((cstart_block << zisofs_block_shift) & PAGE_CACHE_MASK));
+	WARN_ON(start_off - (full_page << PAGE_SHIFT) !=
+		((cstart_block << zisofs_block_shift) & PAGE_MASK));
 
 	/* Find the pointer to this specific chunk */
 	/* Note: we're not using isonum_731() here because the data is known aligned */
@@ -260,10 +260,10 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
 		ret = zisofs_uncompress_block(inode, block_start, block_end,
 					      pcount, pages, poffset, &err);
 		poffset += ret;
-		pages += poffset >> PAGE_CACHE_SHIFT;
-		pcount -= poffset >> PAGE_CACHE_SHIFT;
-		full_page -= poffset >> PAGE_CACHE_SHIFT;
-		poffset &= ~PAGE_CACHE_MASK;
+		pages += poffset >> PAGE_SHIFT;
+		pcount -= poffset >> PAGE_SHIFT;
+		full_page -= poffset >> PAGE_SHIFT;
+		poffset &= ~PAGE_MASK;
 
 		if (err) {
 			brelse(bh);
@@ -282,7 +282,7 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
 
 	if (poffset && *pages) {
 		memset(page_address(*pages) + poffset, 0,
-		       PAGE_CACHE_SIZE - poffset);
+		       PAGE_SIZE - poffset);
 		flush_dcache_page(*pages);
 		SetPageUptodate(*pages);
 	}
@@ -302,12 +302,12 @@ static int zisofs_readpage(struct file *file, struct page *page)
 	int i, pcount, full_page;
 	unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
 	unsigned int zisofs_pages_per_cblock =
-		PAGE_CACHE_SHIFT <= zisofs_block_shift ?
-		(1 << (zisofs_block_shift - PAGE_CACHE_SHIFT)) : 0;
+		PAGE_SHIFT <= zisofs_block_shift ?
+		(1 << (zisofs_block_shift - PAGE_SHIFT)) : 0;
 	struct page *pages[max_t(unsigned, zisofs_pages_per_cblock, 1)];
 	pgoff_t index = page->index, end_index;
 
-	end_index = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	end_index = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	/*
 	 * If this page is wholly outside i_size we just return zero;
 	 * do_generic_file_read() will handle this for us
@@ -318,7 +318,7 @@ static int zisofs_readpage(struct file *file, struct page *page)
 		return 0;
 	}
 
-	if (PAGE_CACHE_SHIFT <= zisofs_block_shift) {
+	if (PAGE_SHIFT <= zisofs_block_shift) {
 		/* We have already been given one page, this is the one
 		   we must do. */
 		full_page = index & (zisofs_pages_per_cblock - 1);
@@ -351,7 +351,7 @@ static int zisofs_readpage(struct file *file, struct page *page)
 			kunmap(pages[i]);
 			unlock_page(pages[i]);
 			if (i != full_page)
-				page_cache_release(pages[i]);
+				put_page(pages[i]);
 		}
 	}