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>

6 files changed, 27 insertions, 27 deletions

diff --git a/fs/ufs/balloc.c b/fs/ufs/balloc.c
index dc5fae6..0447b94 100644
--- a/fs/ufs/balloc.c
+++ b/fs/ufs/balloc.c
@@ -237,7 +237,7 @@ static void ufs_change_blocknr(struct inode *inode, sector_t beg,
 			       sector_t newb, struct page *locked_page)
 {
 	const unsigned blks_per_page =
-		1 << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+		1 << (PAGE_SHIFT - inode->i_blkbits);
 	const unsigned mask = blks_per_page - 1;
 	struct address_space * const mapping = inode->i_mapping;
 	pgoff_t index, cur_index, last_index;
@@ -255,9 +255,9 @@ static void ufs_change_blocknr(struct inode *inode, sector_t beg,
 
 	cur_index = locked_page->index;
 	end = count + beg;
-	last_index = end >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	last_index = end >> (PAGE_SHIFT - inode->i_blkbits);
 	for (i = beg; i < end; i = (i | mask) + 1) {
-		index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+		index = i >> (PAGE_SHIFT - inode->i_blkbits);
 
 		if (likely(cur_index != index)) {
 			page = ufs_get_locked_page(mapping, index);
diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
index 74f2e80..0b14572 100644
--- a/fs/ufs/dir.c
+++ b/fs/ufs/dir.c
@@ -62,7 +62,7 @@ static int ufs_commit_chunk(struct page *page, loff_t pos, unsigned len)
 static inline void ufs_put_page(struct page *page)
 {
 	kunmap(page);
-	page_cache_release(page);
+	put_page(page);
 }
 
 ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
@@ -111,13 +111,13 @@ static void ufs_check_page(struct page *page)
 	struct super_block *sb = dir->i_sb;
 	char *kaddr = page_address(page);
 	unsigned offs, rec_len;
-	unsigned limit = PAGE_CACHE_SIZE;
+	unsigned limit = PAGE_SIZE;
 	const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
 	struct ufs_dir_entry *p;
 	char *error;
 
-	if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
-		limit = dir->i_size & ~PAGE_CACHE_MASK;
+	if ((dir->i_size >> PAGE_SHIFT) == page->index) {
+		limit = dir->i_size & ~PAGE_MASK;
 		if (limit & chunk_mask)
 			goto Ebadsize;
 		if (!limit)
@@ -170,7 +170,7 @@ Einumber:
 bad_entry:
 	ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
 		   "offset=%lu, rec_len=%d, name_len=%d",
-		   dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+		   dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs,
 		   rec_len, ufs_get_de_namlen(sb, p));
 	goto fail;
 Eend:
@@ -178,7 +178,7 @@ Eend:
 	ufs_error(sb, __func__,
 		   "entry in directory #%lu spans the page boundary"
 		   "offset=%lu",
-		   dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
+		   dir->i_ino, (page->index<<PAGE_SHIFT)+offs);
 fail:
 	SetPageChecked(page);
 	SetPageError(page);
@@ -211,9 +211,9 @@ ufs_last_byte(struct inode *inode, unsigned long page_nr)
 {
 	unsigned last_byte = inode->i_size;
 
-	last_byte -= page_nr << PAGE_CACHE_SHIFT;
-	if (last_byte > PAGE_CACHE_SIZE)
-		last_byte = PAGE_CACHE_SIZE;
+	last_byte -= page_nr << PAGE_SHIFT;
+	if (last_byte > PAGE_SIZE)
+		last_byte = PAGE_SIZE;
 	return last_byte;
 }
 
@@ -341,7 +341,7 @@ int ufs_add_link(struct dentry *dentry, struct inode *inode)
 		kaddr = page_address(page);
 		dir_end = kaddr + ufs_last_byte(dir, n);
 		de = (struct ufs_dir_entry *)kaddr;
-		kaddr += PAGE_CACHE_SIZE - reclen;
+		kaddr += PAGE_SIZE - reclen;
 		while ((char *)de <= kaddr) {
 			if ((char *)de == dir_end) {
 				/* We hit i_size */
@@ -432,8 +432,8 @@ ufs_readdir(struct file *file, struct dir_context *ctx)
 	loff_t pos = ctx->pos;
 	struct inode *inode = file_inode(file);
 	struct super_block *sb = inode->i_sb;
-	unsigned int offset = pos & ~PAGE_CACHE_MASK;
-	unsigned long n = pos >> PAGE_CACHE_SHIFT;
+	unsigned int offset = pos & ~PAGE_MASK;
+	unsigned long n = pos >> PAGE_SHIFT;
 	unsigned long npages = dir_pages(inode);
 	unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
 	int need_revalidate = file->f_version != inode->i_version;
@@ -454,14 +454,14 @@ ufs_readdir(struct file *file, struct dir_context *ctx)
 			ufs_error(sb, __func__,
 				  "bad page in #%lu",
 				  inode->i_ino);
-			ctx->pos += PAGE_CACHE_SIZE - offset;
+			ctx->pos += PAGE_SIZE - offset;
 			return -EIO;
 		}
 		kaddr = page_address(page);
 		if (unlikely(need_revalidate)) {
 			if (offset) {
 				offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
-				ctx->pos = (n<<PAGE_CACHE_SHIFT) + offset;
+				ctx->pos = (n<<PAGE_SHIFT) + offset;
 			}
 			file->f_version = inode->i_version;
 			need_revalidate = 0;
@@ -574,7 +574,7 @@ int ufs_make_empty(struct inode * inode, struct inode *dir)
 
 	kmap(page);
 	base = (char*)page_address(page);
-	memset(base, 0, PAGE_CACHE_SIZE);
+	memset(base, 0, PAGE_SIZE);
 
 	de = (struct ufs_dir_entry *) base;
 
@@ -594,7 +594,7 @@ int ufs_make_empty(struct inode * inode, struct inode *dir)
 
 	err = ufs_commit_chunk(page, 0, chunk_size);
 fail:
-	page_cache_release(page);
+	put_page(page);
 	return err;
 }
 
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index d897e16..9f49431 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -1051,13 +1051,13 @@ static int ufs_alloc_lastblock(struct inode *inode, loff_t size)
 	lastfrag--;
 
 	lastpage = ufs_get_locked_page(mapping, lastfrag >>
-				       (PAGE_CACHE_SHIFT - inode->i_blkbits));
+				       (PAGE_SHIFT - inode->i_blkbits));
        if (IS_ERR(lastpage)) {
                err = -EIO;
                goto out;
        }
 
-       end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
+       end = lastfrag & ((1 << (PAGE_SHIFT - inode->i_blkbits)) - 1);
        bh = page_buffers(lastpage);
        for (i = 0; i < end; ++i)
                bh = bh->b_this_page;
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index acf4a3b..a1559f7 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -305,7 +305,7 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0);
 		else {
 			kunmap(dir_page);
-			page_cache_release(dir_page);
+			put_page(dir_page);
 		}
 		inode_dec_link_count(old_dir);
 	}
@@ -315,11 +315,11 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 out_dir:
 	if (dir_de) {
 		kunmap(dir_page);
-		page_cache_release(dir_page);
+		put_page(dir_page);
 	}
 out_old:
 	kunmap(old_page);
-	page_cache_release(old_page);
+	put_page(old_page);
 out:
 	return err;
 }
diff --git a/fs/ufs/util.c b/fs/ufs/util.c
index b6c2f94..a409e3e 100644
--- a/fs/ufs/util.c
+++ b/fs/ufs/util.c
@@ -261,14 +261,14 @@ struct page *ufs_get_locked_page(struct address_space *mapping,
 		if (unlikely(page->mapping == NULL)) {
 			/* Truncate got there first */
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 			page = NULL;
 			goto out;
 		}
 
 		if (!PageUptodate(page) || PageError(page)) {
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 
 			printk(KERN_ERR "ufs_change_blocknr: "
 			       "can not read page: ino %lu, index: %lu\n",
diff --git a/fs/ufs/util.h b/fs/ufs/util.h
index 9541759..b7fbf53 100644
--- a/fs/ufs/util.h
+++ b/fs/ufs/util.h
@@ -283,7 +283,7 @@ extern struct page *ufs_get_locked_page(struct address_space *mapping,
 static inline void ufs_put_locked_page(struct page *page)
 {
        unlock_page(page);
-       page_cache_release(page);
+       put_page(page);
 }