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>

2 files changed, 22 insertions, 22 deletions

diff --git a/fs/btrfs/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c
index 669b582..ac3a06d 100644
--- a/fs/btrfs/tests/extent-io-tests.c
+++ b/fs/btrfs/tests/extent-io-tests.c
@@ -32,8 +32,8 @@ static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
 {
 	int ret;
 	struct page *pages[16];
-	unsigned long index = start >> PAGE_CACHE_SHIFT;
-	unsigned long end_index = end >> PAGE_CACHE_SHIFT;
+	unsigned long index = start >> PAGE_SHIFT;
+	unsigned long end_index = end >> PAGE_SHIFT;
 	unsigned long nr_pages = end_index - index + 1;
 	int i;
 	int count = 0;
@@ -49,9 +49,9 @@ static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
 				count++;
 			if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
 				unlock_page(pages[i]);
-			page_cache_release(pages[i]);
+			put_page(pages[i]);
 			if (flags & PROCESS_RELEASE)
-				page_cache_release(pages[i]);
+				put_page(pages[i]);
 		}
 		nr_pages -= ret;
 		index += ret;
@@ -93,7 +93,7 @@ static int test_find_delalloc(void)
 	 * everything to make sure our pages don't get evicted and screw up our
 	 * test.
 	 */
-	for (index = 0; index < (total_dirty >> PAGE_CACHE_SHIFT); index++) {
+	for (index = 0; index < (total_dirty >> PAGE_SHIFT); index++) {
 		page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
 		if (!page) {
 			test_msg("Failed to allocate test page\n");
@@ -104,7 +104,7 @@ static int test_find_delalloc(void)
 		if (index) {
 			unlock_page(page);
 		} else {
-			page_cache_get(page);
+			get_page(page);
 			locked_page = page;
 		}
 	}
@@ -129,7 +129,7 @@ static int test_find_delalloc(void)
 	}
 	unlock_extent(&tmp, start, end);
 	unlock_page(locked_page);
-	page_cache_release(locked_page);
+	put_page(locked_page);
 
 	/*
 	 * Test this scenario
@@ -139,7 +139,7 @@ static int test_find_delalloc(void)
 	 */
 	test_start = SZ_64M;
 	locked_page = find_lock_page(inode->i_mapping,
-				     test_start >> PAGE_CACHE_SHIFT);
+				     test_start >> PAGE_SHIFT);
 	if (!locked_page) {
 		test_msg("Couldn't find the locked page\n");
 		goto out_bits;
@@ -165,7 +165,7 @@ static int test_find_delalloc(void)
 	}
 	unlock_extent(&tmp, start, end);
 	/* locked_page was unlocked above */
-	page_cache_release(locked_page);
+	put_page(locked_page);
 
 	/*
 	 * Test this scenario
@@ -174,7 +174,7 @@ static int test_find_delalloc(void)
 	 */
 	test_start = max_bytes + 4096;
 	locked_page = find_lock_page(inode->i_mapping, test_start >>
-				     PAGE_CACHE_SHIFT);
+				     PAGE_SHIFT);
 	if (!locked_page) {
 		test_msg("Could'nt find the locked page\n");
 		goto out_bits;
@@ -225,13 +225,13 @@ static int test_find_delalloc(void)
 	 * range we want to find.
 	 */
 	page = find_get_page(inode->i_mapping,
-			     (max_bytes + SZ_1M) >> PAGE_CACHE_SHIFT);
+			     (max_bytes + SZ_1M) >> PAGE_SHIFT);
 	if (!page) {
 		test_msg("Couldn't find our page\n");
 		goto out_bits;
 	}
 	ClearPageDirty(page);
-	page_cache_release(page);
+	put_page(page);
 
 	/* We unlocked it in the previous test */
 	lock_page(locked_page);
@@ -249,9 +249,9 @@ static int test_find_delalloc(void)
 		test_msg("Didn't find our range\n");
 		goto out_bits;
 	}
-	if (start != test_start && end != test_start + PAGE_CACHE_SIZE - 1) {
+	if (start != test_start && end != test_start + PAGE_SIZE - 1) {
 		test_msg("Expected start %Lu end %Lu, got start %Lu end %Lu\n",
-			 test_start, test_start + PAGE_CACHE_SIZE - 1, start,
+			 test_start, test_start + PAGE_SIZE - 1, start,
 			 end);
 		goto out_bits;
 	}
@@ -265,7 +265,7 @@ out_bits:
 	clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_KERNEL);
 out:
 	if (locked_page)
-		page_cache_release(locked_page);
+		put_page(locked_page);
 	process_page_range(inode, 0, total_dirty - 1,
 			   PROCESS_UNLOCK | PROCESS_RELEASE);
 	iput(inode);
@@ -298,9 +298,9 @@ static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb,
 		return -EINVAL;
 	}
 
-	bitmap_set(bitmap, (PAGE_CACHE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
+	bitmap_set(bitmap, (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
 		   sizeof(long) * BITS_PER_BYTE);
-	extent_buffer_bitmap_set(eb, PAGE_CACHE_SIZE - sizeof(long) / 2, 0,
+	extent_buffer_bitmap_set(eb, PAGE_SIZE - sizeof(long) / 2, 0,
 				 sizeof(long) * BITS_PER_BYTE);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Setting straddling pages failed\n");
@@ -309,10 +309,10 @@ static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb,
 
 	bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
 	bitmap_clear(bitmap,
-		     (PAGE_CACHE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
+		     (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
 		     sizeof(long) * BITS_PER_BYTE);
 	extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
-	extent_buffer_bitmap_clear(eb, PAGE_CACHE_SIZE - sizeof(long) / 2, 0,
+	extent_buffer_bitmap_clear(eb, PAGE_SIZE - sizeof(long) / 2, 0,
 				   sizeof(long) * BITS_PER_BYTE);
 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 		test_msg("Clearing straddling pages failed\n");
@@ -353,7 +353,7 @@ static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb,
 
 static int test_eb_bitmaps(void)
 {
-	unsigned long len = PAGE_CACHE_SIZE * 4;
+	unsigned long len = PAGE_SIZE * 4;
 	unsigned long *bitmap;
 	struct extent_buffer *eb;
 	int ret;
@@ -379,7 +379,7 @@ static int test_eb_bitmaps(void)
 
 	/* Do it over again with an extent buffer which isn't page-aligned. */
 	free_extent_buffer(eb);
-	eb = __alloc_dummy_extent_buffer(NULL, PAGE_CACHE_SIZE / 2, len);
+	eb = __alloc_dummy_extent_buffer(NULL, PAGE_SIZE / 2, len);
 	if (!eb) {
 		test_msg("Couldn't allocate test extent buffer\n");
 		kfree(bitmap);
diff --git a/fs/btrfs/tests/free-space-tests.c b/fs/btrfs/tests/free-space-tests.c
index c9ad97b..5142475 100644
--- a/fs/btrfs/tests/free-space-tests.c
+++ b/fs/btrfs/tests/free-space-tests.c
@@ -22,7 +22,7 @@
 #include "../disk-io.h"
 #include "../free-space-cache.h"
 
-#define BITS_PER_BITMAP		(PAGE_CACHE_SIZE * 8)
+#define BITS_PER_BITMAP		(PAGE_SIZE * 8)
 
 /*
  * This test just does basic sanity checking, making sure we can add an exten