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, 22 insertions, 22 deletions

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 1f5865263b3e..e6b1d80952b9 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -122,7 +122,7 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
 				       struct ecryptfs_crypt_stat *crypt_stat)
 {
 	loff_t extent_num_in_page = 0;
-	loff_t num_extents_per_page = (PAGE_CACHE_SIZE
+	loff_t num_extents_per_page = (PAGE_SIZE
 				       / crypt_stat->extent_size);
 	int rc = 0;
 
@@ -138,7 +138,7 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
 			char *page_virt;
 
 			page_virt = kmap_atomic(page);
-			memset(page_virt, 0, PAGE_CACHE_SIZE);
+			memset(page_virt, 0, PAGE_SIZE);
 			/* TODO: Support more than one header extent */
 			if (view_extent_num == 0) {
 				size_t written;
@@ -164,8 +164,8 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
 				 - crypt_stat->metadata_size);
 
 			rc = ecryptfs_read_lower_page_segment(
-				page, (lower_offset >> PAGE_CACHE_SHIFT),
-				(lower_offset & ~PAGE_CACHE_MASK),
+				page, (lower_offset >> PAGE_SHIFT),
+				(lower_offset & ~PAGE_MASK),
 				crypt_stat->extent_size, page->mapping->host);
 			if (rc) {
 				printk(KERN_ERR "%s: Error attempting to read "
@@ -198,7 +198,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
 
 	if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
 		rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
-						      PAGE_CACHE_SIZE,
+						      PAGE_SIZE,
 						      page->mapping->host);
 	} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
 		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
@@ -215,7 +215,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
 
 		} else {
 			rc = ecryptfs_read_lower_page_segment(
-				page, page->index, 0, PAGE_CACHE_SIZE,
+				page, page->index, 0, PAGE_SIZE,
 				page->mapping->host);
 			if (rc) {
 				printk(KERN_ERR "Error reading page; rc = "
@@ -250,12 +250,12 @@ static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
 	struct inode *inode = page->mapping->host;
 	int end_byte_in_page;
 
-	if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index)
+	if ((i_size_read(inode) / PAGE_SIZE) != page->index)
 		goto out;
-	end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
+	end_byte_in_page = i_size_read(inode) % PAGE_SIZE;
 	if (to > end_byte_in_page)
 		end_byte_in_page = to;
-	zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE);
+	zero_user_segment(page, end_byte_in_page, PAGE_SIZE);
 out:
 	return 0;
 }
@@ -279,7 +279,7 @@ static int ecryptfs_write_begin(struct file *file,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+	pgoff_t index = pos >> PAGE_SHIFT;
 	struct page *page;
 	loff_t prev_page_end_size;
 	int rc = 0;
@@ -289,14 +289,14 @@ static int ecryptfs_write_begin(struct file *file,
 		return -ENOMEM;
 	*pagep = page;
 
-	prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
+	prev_page_end_size = ((loff_t)index << PAGE_SHIFT);
 	if (!PageUptodate(page)) {
 		struct ecryptfs_crypt_stat *crypt_stat =
 			&ecryptfs_inode_to_private(mapping->host)->crypt_stat;
 
 		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
 			rc = ecryptfs_read_lower_page_segment(
-				page, index, 0, PAGE_CACHE_SIZE, mapping->host);
+				page, index, 0, PAGE_SIZE, mapping->host);
 			if (rc) {
 				printk(KERN_ERR "%s: Error attempting to read "
 				       "lower page segment; rc = [%d]\n",
@@ -322,7 +322,7 @@ static int ecryptfs_write_begin(struct file *file,
 				SetPageUptodate(page);
 			} else {
 				rc = ecryptfs_read_lower_page_segment(
-					page, index, 0, PAGE_CACHE_SIZE,
+					page, index, 0, PAGE_SIZE,
 					mapping->host);
 				if (rc) {
 					printk(KERN_ERR "%s: Error reading "
@@ -336,9 +336,9 @@ static int ecryptfs_write_begin(struct file *file,
 		} else {
 			if (prev_page_end_size
 			    >= i_size_read(page->mapping->host)) {
-				zero_user(page, 0, PAGE_CACHE_SIZE);
+				zero_user(page, 0, PAGE_SIZE);
 				SetPageUptodate(page);
-			} else if (len < PAGE_CACHE_SIZE) {
+			} else if (len < PAGE_SIZE) {
 				rc = ecryptfs_decrypt_page(page);
 				if (rc) {
 					printk(KERN_ERR "%s: Error decrypting "
@@ -371,11 +371,11 @@ static int ecryptfs_write_begin(struct file *file,
 	 * of page?  Zero it out. */
 	if ((i_size_read(mapping->host) == prev_page_end_size)
 	    && (pos != 0))
-		zero_user(page, 0, PAGE_CACHE_SIZE);
+		zero_user(page, 0, PAGE_SIZE);
 out:
 	if (unlikely(rc)) {
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		*pagep = NULL;
 	}
 	return rc;
@@ -437,7 +437,7 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
 	}
 	inode_lock(lower_inode);
 	size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
-					   xattr_virt, PAGE_CACHE_SIZE);
+					   xattr_virt, PAGE_SIZE);
 	if (size < 0)
 		size = 8;
 	put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
@@ -479,8 +479,8 @@ static int ecryptfs_write_end(struct file *file,
 			loff_t pos, unsigned len, unsigned copied,
 			struct page *page, void *fsdata)
 {
-	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
-	unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+	pgoff_t index = pos >> PAGE_SHIFT;
+	unsigned from = pos & (PAGE_SIZE - 1);
 	unsigned to = from + copied;
 	struct inode *ecryptfs_inode = mapping->host;
 	struct ecryptfs_crypt_stat *crypt_stat =
@@ -500,7 +500,7 @@ static int ecryptfs_write_end(struct file *file,
 		goto out;
 	}
 	if (!PageUptodate(page)) {
-		if (copied < PAGE_CACHE_SIZE) {
+		if (copied < PAGE_SIZE) {
 			rc = 0;
 			goto out;
 		}
@@ -533,7 +533,7 @@ static int ecryptfs_write_end(struct file *file,
 		rc = copied;
 out:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return rc;
 }