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, 15 insertions, 15 deletions

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index b892914968c1..298631eaee78 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -226,7 +226,7 @@ int btree_readahead_hook(struct btrfs_fs_info *fs_info,
 	/* find extent */
 	spin_lock(&fs_info->reada_lock);
 	re = radix_tree_lookup(&fs_info->reada_tree,
-			       start >> PAGE_CACHE_SHIFT);
+			       start >> PAGE_SHIFT);
 	if (re)
 		re->refcnt++;
 	spin_unlock(&fs_info->reada_lock);
@@ -257,7 +257,7 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info,
 	zone = NULL;
 	spin_lock(&fs_info->reada_lock);
 	ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,
-				     logical >> PAGE_CACHE_SHIFT, 1);
+				     logical >> PAGE_SHIFT, 1);
 	if (ret == 1 && logical >= zone->start && logical <= zone->end) {
 		kref_get(&zone->refcnt);
 		spin_unlock(&fs_info->reada_lock);
@@ -294,13 +294,13 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info,
 
 	spin_lock(&fs_info->reada_lock);
 	ret = radix_tree_insert(&dev->reada_zones,
-				(unsigned long)(zone->end >> PAGE_CACHE_SHIFT),
+				(unsigned long)(zone->end >> PAGE_SHIFT),
 				zone);
 
 	if (ret == -EEXIST) {
 		kfree(zone);
 		ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,
-					     logical >> PAGE_CACHE_SHIFT, 1);
+					     logical >> PAGE_SHIFT, 1);
 		if (ret == 1 && logical >= zone->start && logical <= zone->end)
 			kref_get(&zone->refcnt);
 		else
@@ -326,7 +326,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
 	u64 length;
 	int real_stripes;
 	int nzones = 0;
-	unsigned long index = logical >> PAGE_CACHE_SHIFT;
+	unsigned long index = logical >> PAGE_SHIFT;
 	int dev_replace_is_ongoing;
 	int have_zone = 0;
 
@@ -495,7 +495,7 @@ static void reada_extent_put(struct btrfs_fs_info *fs_info,
 			     struct reada_extent *re)
 {
 	int i;
-	unsigned long index = re->logical >> PAGE_CACHE_SHIFT;
+	unsigned long index = re->logical >> PAGE_SHIFT;
 
 	spin_lock(&fs_info->reada_lock);
 	if (--re->refcnt) {
@@ -538,7 +538,7 @@ static void reada_zone_release(struct kref *kref)
 	struct reada_zone *zone = container_of(kref, struct reada_zone, refcnt);
 
 	radix_tree_delete(&zone->device->reada_zones,
-			  zone->end >> PAGE_CACHE_SHIFT);
+			  zone->end >> PAGE_SHIFT);
 
 	kfree(zone);
 }
@@ -587,7 +587,7 @@ static int reada_add_block(struct reada_control *rc, u64 logical,
 static void reada_peer_zones_set_lock(struct reada_zone *zone, int lock)
 {
 	int i;
-	unsigned long index = zone->end >> PAGE_CACHE_SHIFT;
+	unsigned long index = zone->end >> PAGE_SHIFT;
 
 	for (i = 0; i < zone->ndevs; ++i) {
 		struct reada_zone *peer;
@@ -622,7 +622,7 @@ static int reada_pick_zone(struct btrfs_device *dev)
 					     (void **)&zone, index, 1);
 		if (ret == 0)
 			break;
-		index = (zone->end >> PAGE_CACHE_SHIFT) + 1;
+		index = (zone->end >> PAGE_SHIFT) + 1;
 		if (zone->locked) {
 			if (zone->elems > top_locked_elems) {
 				top_locked_elems = zone->elems;
@@ -673,7 +673,7 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
 	 * plugging to speed things up
 	 */
 	ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re,
-				     dev->reada_next >> PAGE_CACHE_SHIFT, 1);
+				     dev->reada_next >> PAGE_SHIFT, 1);
 	if (ret == 0 || re->logical > dev->reada_curr_zone->end) {
 		ret = reada_pick_zone(dev);
 		if (!ret) {
@@ -682,7 +682,7 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
 		}
 		re = NULL;
 		ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re,
-					dev->reada_next >> PAGE_CACHE_SHIFT, 1);
+					dev->reada_next >> PAGE_SHIFT, 1);
 	}
 	if (ret == 0) {
 		spin_unlock(&fs_info->reada_lock);
@@ -838,7 +838,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
 				printk(KERN_CONT " curr off %llu",
 					device->reada_next - zone->start);
 			printk(KERN_CONT "\n");
-			index = (zone->end >> PAGE_CACHE_SHIFT) + 1;
+			index = (zone->end >> PAGE_SHIFT) + 1;
 		}
 		cnt = 0;
 		index = 0;
@@ -864,7 +864,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
 				}
 			}
 			printk(KERN_CONT "\n");
-			index = (re->logical >> PAGE_CACHE_SHIFT) + 1;
+			index = (re->logical >> PAGE_SHIFT) + 1;
 			if (++cnt > 15)
 				break;
 		}
@@ -880,7 +880,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
 		if (ret == 0)
 			break;
 		if (!re->scheduled) {
-			index = (re->logical >> PAGE_CACHE_SHIFT) + 1;
+			index = (re->logical >> PAGE_SHIFT) + 1;
 			continue;
 		}
 		printk(KERN_DEBUG
@@ -897,7 +897,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
 			}
 		}
 		printk(KERN_CONT "\n");
-		index = (re->logical >> PAGE_CACHE_SHIFT) + 1;
+		index = (re->logical >> PAGE_SHIFT) + 1;
 	}
 	spin_unlock(&fs_info->reada_lock);
 }