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, 16 insertions, 16 deletions

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index a2f051347731..1adfbe7be6b8 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -55,8 +55,8 @@ static struct list_head *lzo_alloc_workspace(void)
 		return ERR_PTR(-ENOMEM);
 
 	workspace->mem = vmalloc(LZO1X_MEM_COMPRESS);
-	workspace->buf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
-	workspace->cbuf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
+	workspace->buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
+	workspace->cbuf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
 	if (!workspace->mem || !workspace->buf || !workspace->cbuf)
 		goto fail;
 
@@ -116,7 +116,7 @@ static int lzo_compress_pages(struct list_head *ws,
 	*total_out = 0;
 	*total_in = 0;
 
-	in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+	in_page = find_get_page(mapping, start >> PAGE_SHIFT);
 	data_in = kmap(in_page);
 
 	/*
@@ -133,10 +133,10 @@ static int lzo_compress_pages(struct list_head *ws,
 	tot_out = LZO_LEN;
 	pages[0] = out_page;
 	nr_pages = 1;
-	pg_bytes_left = PAGE_CACHE_SIZE - LZO_LEN;
+	pg_bytes_left = PAGE_SIZE - LZO_LEN;
 
 	/* compress at most one page of data each time */
-	in_len = min(len, PAGE_CACHE_SIZE);
+	in_len = min(len, PAGE_SIZE);
 	while (tot_in < len) {
 		ret = lzo1x_1_compress(data_in, in_len, workspace->cbuf,
 				       &out_len, workspace->mem);
@@ -201,7 +201,7 @@ static int lzo_compress_pages(struct list_head *ws,
 				cpage_out = kmap(out_page);
 				pages[nr_pages++] = out_page;
 
-				pg_bytes_left = PAGE_CACHE_SIZE;
+				pg_bytes_left = PAGE_SIZE;
 				out_offset = 0;
 			}
 		}
@@ -221,12 +221,12 @@ static int lzo_compress_pages(struct list_head *ws,
 
 		bytes_left = len - tot_in;
 		kunmap(in_page);
-		page_cache_release(in_page);
+		put_page(in_page);
 
-		start += PAGE_CACHE_SIZE;
-		in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+		start += PAGE_SIZE;
+		in_page = find_get_page(mapping, start >> PAGE_SHIFT);
 		data_in = kmap(in_page);
-		in_len = min(bytes_left, PAGE_CACHE_SIZE);
+		in_len = min(bytes_left, PAGE_SIZE);
 	}
 
 	if (tot_out > tot_in)
@@ -248,7 +248,7 @@ out:
 
 	if (in_page) {
 		kunmap(in_page);
-		page_cache_release(in_page);
+		put_page(in_page);
 	}
 
 	return ret;
@@ -266,7 +266,7 @@ static int lzo_decompress_biovec(struct list_head *ws,
 	char *data_in;
 	unsigned long page_in_index = 0;
 	unsigned long page_out_index = 0;
-	unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_CACHE_SIZE);
+	unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
 	unsigned long buf_start;
 	unsigned long buf_offset = 0;
 	unsigned long bytes;
@@ -289,7 +289,7 @@ static int lzo_decompress_biovec(struct list_head *ws,
 	tot_in = LZO_LEN;
 	in_offset = LZO_LEN;
 	tot_len = min_t(size_t, srclen, tot_len);
-	in_page_bytes_left = PAGE_CACHE_SIZE - LZO_LEN;
+	in_page_bytes_left = PAGE_SIZE - LZO_LEN;
 
 	tot_out = 0;
 	pg_offset = 0;
@@ -345,12 +345,12 @@ cont:
 
 				data_in = kmap(pages_in[++page_in_index]);
 
-				in_page_bytes_left = PAGE_CACHE_SIZE;
+				in_page_bytes_left = PAGE_SIZE;
 				in_offset = 0;
 			}
 		}
 
-		out_len = lzo1x_worst_compress(PAGE_CACHE_SIZE);
+		out_len = lzo1x_worst_compress(PAGE_SIZE);
 		ret = lzo1x_decompress_safe(buf, in_len, workspace->buf,
 					    &out_len);
 		if (need_unmap)
@@ -399,7 +399,7 @@ static int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	in_len = read_compress_length(data_in);
 	data_in += LZO_LEN;
 
-	out_len = PAGE_CACHE_SIZE;
+	out_len = PAGE_SIZE;
 	ret = lzo1x_decompress_safe(data_in, in_len, workspace->buf, &out_len);
 	if (ret != LZO_E_OK) {
 		printk(KERN_WARNING "BTRFS: decompress failed!\n");