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, 42 insertions, 42 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 053e677839fe..94a0c8a3e871 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -898,7 +898,7 @@ static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 	u64 end;
 
 	read_lock(&em_tree->lock);
-	em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
+	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 	read_unlock(&em_tree->lock);
 
 	if (em) {
@@ -988,7 +988,7 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 	struct extent_map *em;
-	u64 len = PAGE_CACHE_SIZE;
+	u64 len = PAGE_SIZE;
 
 	/*
 	 * hopefully we have this extent in the tree already, try without
@@ -1124,15 +1124,15 @@ static int cluster_pages_for_defrag(struct inode *inode,
 	struct extent_io_tree *tree;
 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 
-	file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
+	file_end = (isize - 1) >> PAGE_SHIFT;
 	if (!isize || start_index > file_end)
 		return 0;
 
 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
 
 	ret = btrfs_delalloc_reserve_space(inode,
-			start_index << PAGE_CACHE_SHIFT,
-			page_cnt << PAGE_CACHE_SHIFT);
+			start_index << PAGE_SHIFT,
+			page_cnt << PAGE_SHIFT);
 	if (ret)
 		return ret;
 	i_done = 0;
@@ -1148,7 +1148,7 @@ again:
 			break;
 
 		page_start = page_offset(page);
-		page_end = page_start + PAGE_CACHE_SIZE - 1;
+		page_end = page_start + PAGE_SIZE - 1;
 		while (1) {
 			lock_extent_bits(tree, page_start, page_end,
 					 &cached_state);
@@ -1169,7 +1169,7 @@ again:
 			 */
 			if (page->mapping != inode->i_mapping) {
 				unlock_page(page);
-				page_cache_release(page);
+				put_page(page);
 				goto again;
 			}
 		}
@@ -1179,7 +1179,7 @@ again:
 			lock_page(page);
 			if (!PageUptodate(page)) {
 				unlock_page(page);
-				page_cache_release(page);
+				put_page(page);
 				ret = -EIO;
 				break;
 			}
@@ -1187,7 +1187,7 @@ again:
 
 		if (page->mapping != inode->i_mapping) {
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 			goto again;
 		}
 
@@ -1208,7 +1208,7 @@ again:
 		wait_on_page_writeback(pages[i]);
 
 	page_start = page_offset(pages[0]);
-	page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
+	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
 
 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
 			 page_start, page_end - 1, &cached_state);
@@ -1222,8 +1222,8 @@ again:
 		BTRFS_I(inode)->outstanding_extents++;
 		spin_unlock(&BTRFS_I(inode)->lock);
 		btrfs_delalloc_release_space(inode,
-				start_index << PAGE_CACHE_SHIFT,
-				(page_cnt - i_done) << PAGE_CACHE_SHIFT);
+				start_index << PAGE_SHIFT,
+				(page_cnt - i_done) << PAGE_SHIFT);
 	}
 
 
@@ -1240,17 +1240,17 @@ again:
 		set_page_extent_mapped(pages[i]);
 		set_page_dirty(pages[i]);
 		unlock_page(pages[i]);
-		page_cache_release(pages[i]);
+		put_page(pages[i]);
 	}
 	return i_done;
 out:
 	for (i = 0; i < i_done; i++) {
 		unlock_page(pages[i]);
-		page_cache_release(pages[i]);
+		put_page(pages[i]);
 	}
 	btrfs_delalloc_release_space(inode,
-			start_index << PAGE_CACHE_SHIFT,
-			page_cnt << PAGE_CACHE_SHIFT);
+			start_index << PAGE_SHIFT,
+			page_cnt << PAGE_SHIFT);
 	return ret;
 
 }
@@ -1273,7 +1273,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 	int defrag_count = 0;
 	int compress_type = BTRFS_COMPRESS_ZLIB;
 	u32 extent_thresh = range->extent_thresh;
-	unsigned long max_cluster = SZ_256K >> PAGE_CACHE_SHIFT;
+	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
 	unsigned long cluster = max_cluster;
 	u64 new_align = ~((u64)SZ_128K - 1);
 	struct page **pages = NULL;
@@ -1317,9 +1317,9 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 	/* find the last page to defrag */
 	if (range->start + range->len > range->start) {
 		last_index = min_t(u64, isize - 1,
-			 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
+			 range->start + range->len - 1) >> PAGE_SHIFT;
 	} else {
-		last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+		last_index = (isize - 1) >> PAGE_SHIFT;
 	}
 
 	if (newer_than) {
@@ -1331,11 +1331,11 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 			 * we always align our defrag to help keep
 			 * the extents in the file evenly spaced
 			 */
-			i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
+			i = (newer_off & new_align) >> PAGE_SHIFT;
 		} else
 			goto out_ra;
 	} else {
-		i = range->start >> PAGE_CACHE_SHIFT;
+		i = range->start >> PAGE_SHIFT;
 	}
 	if (!max_to_defrag)
 		max_to_defrag = last_index - i + 1;
@@ -1348,7 +1348,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 		inode->i_mapping->writeback_index = i;
 
 	while (i <= last_index && defrag_count < max_to_defrag &&
-	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE))) {
+	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
 		/*
 		 * make sure we stop running if someone unmounts
 		 * the FS
@@ -1362,7 +1362,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 			break;
 		}
 
-		if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
+		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
 					 extent_thresh, &last_len, &skip,
 					 &defrag_end, range->flags &
 					 BTRFS_DEFRAG_RANGE_COMPRESS)) {
@@ -1371,14 +1371,14 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 			 * the should_defrag function tells us how much to skip
 			 * bump our counter by the suggested amount
 			 */
-			next = DIV_ROUND_UP(skip, PAGE_CACHE_SIZE);
+			next = DIV_ROUND_UP(skip, PAGE_SIZE);
 			i = max(i + 1, next);
 			continue;
 		}
 
 		if (!newer_than) {
-			cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
-				   PAGE_CACHE_SHIFT) - i;
+			cluster = (PAGE_ALIGN(defrag_end) >>
+				   PAGE_SHIFT) - i;
 			cluster = min(cluster, max_cluster);
 		} else {
 			cluster = max_cluster;
@@ -1412,20 +1412,20 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 				i += ret;
 
 			newer_off = max(newer_off + 1,
-					(u64)i << PAGE_CACHE_SHIFT);
+					(u64)i << PAGE_SHIFT);
 
 			ret = find_new_extents(root, inode, newer_than,
 					       &newer_off, SZ_64K);
 			if (!ret) {
 				range->start = newer_off;
-				i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
+				i = (newer_off & new_align) >> PAGE_SHIFT;
 			} else {
 				break;
 			}
 		} else {
 			if (ret > 0) {
 				i += ret;
-				last_len += ret << PAGE_CACHE_SHIFT;
+				last_len += ret << PAGE_SHIFT;
 			} else {
 				i++;
 				last_len = 0;
@@ -1722,7 +1722,7 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
 		readonly = true;
 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
-		if (vol_args->size > PAGE_CACHE_SIZE) {
+		if (vol_args->size > PAGE_SIZE) {
 			ret = -EINVAL;
 			goto free_args;
 		}
@@ -2806,12 +2806,12 @@ static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
 		lock_page(page);
 		if (!PageUptodate(page)) {
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 			return ERR_PTR(-EIO);
 		}
 		if (page->mapping != inode->i_mapping) {
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 			return ERR_PTR(-EAGAIN);
 		}
 	}
@@ -2823,7 +2823,7 @@ static int gather_extent_pages(struct inode *inode, struct page **pages,
 			       int num_pages, u64 off)
 {
 	int i;
-	pgoff_t index = off >> PAGE_CACHE_SHIFT;
+	pgoff_t index = off >> PAGE_SHIFT;
 
 	for (i = 0; i < num_pages; i++) {
 again:
@@ -2932,12 +2932,12 @@ static void btrfs_cmp_data_free(struct cmp_pages *cmp)
 		pg = cmp->src_pages[i];
 		if (pg) {
 			unlock_page(pg);
-			page_cache_release(pg);
+			put_page(pg);
 		}
 		pg = cmp->dst_pages[i];
 		if (pg) {
 			unlock_page(pg);
-			page_cache_release(pg);
+			put_page(pg);
 		}
 	}
 	kfree(cmp->src_pages);
@@ -2949,7 +2949,7 @@ static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
 				  u64 len, struct cmp_pages *cmp)
 {
 	int ret;
-	int num_pages = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT;
+	int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
 	struct page **src_pgarr, **dst_pgarr;
 
 	/*
@@ -2987,12 +2987,12 @@ static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
 	int ret = 0;
 	int i;
 	struct page *src_page, *dst_page;
-	unsigned int cmp_len = PAGE_CACHE_SIZE;
+	unsigned int cmp_len = PAGE_SIZE;
 	void *addr, *dst_addr;
 
 	i = 0;
 	while (len) {
-		if (len < PAGE_CACHE_SIZE)
+		if (len < PAGE_SIZE)
 			cmp_len = len;
 
 		BUG_ON(i >= cmp->num_pages);
@@ -3191,7 +3191,7 @@ ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
 	if (olen > BTRFS_MAX_DEDUPE_LEN)
 		olen = BTRFS_MAX_DEDUPE_LEN;
 
-	if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) {
+	if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
 		/*
 		 * Btrfs does not support blocksize < page_size. As a
 		 * result, btrfs_cmp_data() won't correctly handle
@@ -3891,8 +3891,8 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
 	 * data immediately and not the previous data.
 	 */
 	truncate_inode_pages_range(&inode->i_data,
-				round_down(destoff, PAGE_CACHE_SIZE),
-				round_up(destoff + len, PAGE_CACHE_SIZE) - 1);
+				round_down(destoff, PAGE_SIZE),
+				round_up(destoff + len, PAGE_SIZE) - 1);
 out_unlock:
 	if (!same_inode)
 		btrfs_double_inode_unlock(src, inode);
@@ -4124,7 +4124,7 @@ static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
 	/* we generally have at most 6 or so space infos, one for each raid
 	 * level.  So, a whole page should be more than enough for everyone
 	 */
-	if (alloc_size > PAGE_CACHE_SIZE)
+	if (alloc_size > PAGE_SIZE)
 		return -ENOMEM;
 
 	space_args.total_spaces = 0;