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/ext4/mballoc.c b/fs/ext4/mballoc.c
index 50e05df28f66..c12174711ce2 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -839,7 +839,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 	sb = inode->i_sb;
 	ngroups = ext4_get_groups_count(sb);
 	blocksize = 1 << inode->i_blkbits;
-	blocks_per_page = PAGE_CACHE_SIZE / blocksize;
+	blocks_per_page = PAGE_SIZE / blocksize;
 
 	groups_per_page = blocks_per_page >> 1;
 	if (groups_per_page == 0)
@@ -993,7 +993,7 @@ static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
 	e4b->bd_buddy_page = NULL;
 	e4b->bd_bitmap_page = NULL;
 
-	blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+	blocks_per_page = PAGE_SIZE / sb->s_blocksize;
 	/*
 	 * the buddy cache inode stores the block bitmap
 	 * and buddy information in consecutive blocks.
@@ -1028,11 +1028,11 @@ static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
 {
 	if (e4b->bd_bitmap_page) {
 		unlock_page(e4b->bd_bitmap_page);
-		page_cache_release(e4b->bd_bitmap_page);
+		put_page(e4b->bd_bitmap_page);
 	}
 	if (e4b->bd_buddy_page) {
 		unlock_page(e4b->bd_buddy_page);
-		page_cache_release(e4b->bd_buddy_page);
+		put_page(e4b->bd_buddy_page);
 	}
 }
 
@@ -1125,7 +1125,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
 	might_sleep();
 	mb_debug(1, "load group %u\n", group);
 
-	blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+	blocks_per_page = PAGE_SIZE / sb->s_blocksize;
 	grp = ext4_get_group_info(sb, group);
 
 	e4b->bd_blkbits = sb->s_blocksize_bits;
@@ -1167,7 +1167,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
 			 * is yet to initialize the same. So
 			 * wait for it to initialize.
 			 */
-			page_cache_release(page);
+			put_page(page);
 		page = find_or_create_page(inode->i_mapping, pnum, gfp);
 		if (page) {
 			BUG_ON(page->mapping != inode->i_mapping);
@@ -1203,7 +1203,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
 	page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
 	if (page == NULL || !PageUptodate(page)) {
 		if (page)
-			page_cache_release(page);
+			put_page(page);
 		page = find_or_create_page(inode->i_mapping, pnum, gfp);
 		if (page) {
 			BUG_ON(page->mapping != inode->i_mapping);
@@ -1238,11 +1238,11 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
 
 err:
 	if (page)
-		page_cache_release(page);
+		put_page(page);
 	if (e4b->bd_bitmap_page)
-		page_cache_release(e4b->bd_bitmap_page);
+		put_page(e4b->bd_bitmap_page);
 	if (e4b->bd_buddy_page)
-		page_cache_release(e4b->bd_buddy_page);
+		put_page(e4b->bd_buddy_page);
 	e4b->bd_buddy = NULL;
 	e4b->bd_bitmap = NULL;
 	return ret;
@@ -1257,9 +1257,9 @@ static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
 {
 	if (e4b->bd_bitmap_page)
-		page_cache_release(e4b->bd_bitmap_page);
+		put_page(e4b->bd_bitmap_page);
 	if (e4b->bd_buddy_page)
-		page_cache_release(e4b->bd_buddy_page);
+		put_page(e4b->bd_buddy_page);
 }
 
 
@@ -2833,8 +2833,8 @@ static void ext4_free_data_callback(struct super_block *sb,
 		/* No more items in the per group rb tree
 		 * balance refcounts from ext4_mb_free_metadata()
 		 */
-		page_cache_release(e4b.bd_buddy_page);
-		page_cache_release(e4b.bd_bitmap_page);
+		put_page(e4b.bd_buddy_page);
+		put_page(e4b.bd_bitmap_page);
 	}
 	ext4_unlock_group(sb, entry->efd_group);
 	kmem_cache_free(ext4_free_data_cachep, entry);
@@ -4385,9 +4385,9 @@ static int ext4_mb_release_context(struct ext4_allocation_context *ac)
 		ext4_mb_put_pa(ac, ac->ac_sb, pa);
 	}
 	if (ac->ac_bitmap_page)
-		page_cache_release(ac->ac_bitmap_page);
+		put_page(ac->ac_bitmap_page);
 	if (ac->ac_buddy_page)
-		page_cache_release(ac->ac_buddy_page);
+		put_page(ac->ac_buddy_page);
 	if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
 		mutex_unlock(&ac->ac_lg->lg_mutex);
 	ext4_mb_collect_stats(ac);
@@ -4599,8 +4599,8 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
 		 * otherwise we'll refresh it from
 		 * on-disk bitmap and lose not-yet-available
 		 * blocks */
-		page_cache_get(e4b->bd_buddy_page);
-		page_cache_get(e4b->bd_bitmap_page);
+		get_page(e4b->bd_buddy_page);
+		get_page(e4b->bd_bitmap_page);
 	}
 	while (*n) {
 		parent = *n;