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>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 64026e5..d09cb4c 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -286,7 +286,7 @@
 		pg = virt_to_page(addr);
 		offset = offset_in_page(addr);
 		sg_set_page(&sg[i], pg, 0, offset);
-		remainder_of_page = PAGE_CACHE_SIZE - offset;
+		remainder_of_page = PAGE_SIZE - offset;
 		if (size >= remainder_of_page) {
 			sg[i].length = remainder_of_page;
 			addr += remainder_of_page;
@@ -400,7 +400,7 @@
 				    struct page *page)
 {
 	return ecryptfs_lower_header_size(crypt_stat) +
-	       ((loff_t)page->index << PAGE_CACHE_SHIFT);
+	       ((loff_t)page->index << PAGE_SHIFT);
 }
 
 /**
@@ -428,7 +428,7 @@
 	size_t extent_size = crypt_stat->extent_size;
 	int rc;
 
-	extent_base = (((loff_t)page_index) * (PAGE_CACHE_SIZE / extent_size));
+	extent_base = (((loff_t)page_index) * (PAGE_SIZE / extent_size));
 	rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
 				(extent_base + extent_offset));
 	if (rc) {
@@ -498,7 +498,7 @@
 	}
 
 	for (extent_offset = 0;
-	     extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
+	     extent_offset < (PAGE_SIZE / crypt_stat->extent_size);
 	     extent_offset++) {
 		rc = crypt_extent(crypt_stat, enc_extent_page, page,
 				  extent_offset, ENCRYPT);
@@ -512,7 +512,7 @@
 	lower_offset = lower_offset_for_page(crypt_stat, page);
 	enc_extent_virt = kmap(enc_extent_page);
 	rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset,
-				  PAGE_CACHE_SIZE);
+				  PAGE_SIZE);
 	kunmap(enc_extent_page);
 	if (rc < 0) {
 		ecryptfs_printk(KERN_ERR,
@@ -560,7 +560,7 @@
 
 	lower_offset = lower_offset_for_page(crypt_stat, page);
 	page_virt = kmap(page);
-	rc = ecryptfs_read_lower(page_virt, lower_offset, PAGE_CACHE_SIZE,
+	rc = ecryptfs_read_lower(page_virt, lower_offset, PAGE_SIZE,
 				 ecryptfs_inode);
 	kunmap(page);
 	if (rc < 0) {
@@ -571,7 +571,7 @@
 	}
 
 	for (extent_offset = 0;
-	     extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
+	     extent_offset < (PAGE_SIZE / crypt_stat->extent_size);
 	     extent_offset++) {
 		rc = crypt_extent(crypt_stat, page, page,
 				  extent_offset, DECRYPT);
@@ -659,11 +659,11 @@
 	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
 		crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 	else {
-		if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
+		if (PAGE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
 			crypt_stat->metadata_size =
 				ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 		else
-			crypt_stat->metadata_size = PAGE_CACHE_SIZE;
+			crypt_stat->metadata_size = PAGE_SIZE;
 	}
 }
 
@@ -1442,7 +1442,7 @@
 						ECRYPTFS_VALIDATE_HEADER_SIZE);
 	if (rc) {
 		/* metadata is not in the file header, so try xattrs */
-		memset(page_virt, 0, PAGE_CACHE_SIZE);
+		memset(page_virt, 0, PAGE_SIZE);
 		rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode);
 		if (rc) {
 			printk(KERN_DEBUG "Valid eCryptfs headers not found in "
@@ -1475,7 +1475,7 @@
 	}
 out:
 	if (page_virt) {
-		memset(page_virt, 0, PAGE_CACHE_SIZE);
+		memset(page_virt, 0, PAGE_SIZE);
 		kmem_cache_free(ecryptfs_header_cache, page_virt);
 	}
 	return rc;
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 121114e..2a988f3 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -765,8 +765,8 @@
 		 * in which ia->ia_size is located. Fill in the end of
 		 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
 		 * PAGE_CACHE_SIZE with zeros. */
-		size_t num_zeros = (PAGE_CACHE_SIZE
-				    - (ia->ia_size & ~PAGE_CACHE_MASK));
+		size_t num_zeros = (PAGE_SIZE
+				    - (ia->ia_size & ~PAGE_MASK));
 
 		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
 			truncate_setsize(inode, ia->ia_size);
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 9893d15..3cf1546 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -1798,7 +1798,7 @@
 	 * added the our &auth_tok_list */
 	next_packet_is_auth_tok_packet = 1;
 	while (next_packet_is_auth_tok_packet) {
-		size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
+		size_t max_packet_size = ((PAGE_SIZE - 8) - i);
 
 		switch (src[i]) {
 		case ECRYPTFS_TAG_3_PACKET_TYPE:
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 8b0b4a7..1698132 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -695,12 +695,12 @@
 	{
 		.cache = &ecryptfs_header_cache,
 		.name = "ecryptfs_headers",
-		.size = PAGE_CACHE_SIZE,
+		.size = PAGE_SIZE,
 	},
 	{
 		.cache = &ecryptfs_xattr_cache,
 		.name = "ecryptfs_xattr_cache",
-		.size = PAGE_CACHE_SIZE,
+		.size = PAGE_SIZE,
 	},
 	{
 		.cache = &ecryptfs_key_record_cache,
@@ -818,7 +818,7 @@
 {
 	int rc;
 
-	if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
+	if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) {
 		rc = -EINVAL;
 		ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 				"larger than the host's page size, and so "
@@ -826,7 +826,7 @@
 				"default eCryptfs extent size is [%u] bytes; "
 				"the page size is [%lu] bytes.\n",
 				ECRYPTFS_DEFAULT_EXTENT_SIZE,
-				(unsigned long)PAGE_CACHE_SIZE);
+				(unsigned long)PAGE_SIZE);
 		goto out;
 	}
 	rc = ecryptfs_init_kmem_caches();
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 1f58652..e6b1d80 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -122,7 +122,7 @@
 				       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 @@
 			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 @@
 				 - 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 @@
 
 	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 @@
 
 		} 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 @@
 	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 @@
 			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 @@
 		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 @@
 				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 @@
 		} 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 @@
 	 * 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 @@
 	}
 	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 @@
 			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 @@
 		goto out;
 	}
 	if (!PageUptodate(page)) {
-		if (copied < PAGE_CACHE_SIZE) {
+		if (copied < PAGE_SIZE) {
 			rc = 0;
 			goto out;
 		}
@@ -533,7 +533,7 @@
 		rc = copied;
 out:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return rc;
 }
 
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 09fe622..158a3a3 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -74,7 +74,7 @@
 	loff_t offset;
 	int rc;
 
-	offset = ((((loff_t)page_for_lower->index) << PAGE_CACHE_SHIFT)
+	offset = ((((loff_t)page_for_lower->index) << PAGE_SHIFT)
 		  + offset_in_page);
 	virt = kmap(page_for_lower);
 	rc = ecryptfs_write_lower(ecryptfs_inode, virt, offset, size);
@@ -123,9 +123,9 @@
 	else
 		pos = offset;
 	while (pos < (offset + size)) {
-		pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT);
-		size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK);
-		size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page);
+		pgoff_t ecryptfs_page_idx = (pos >> PAGE_SHIFT);
+		size_t start_offset_in_page = (pos & ~PAGE_MASK);
+		size_t num_bytes = (PAGE_SIZE - start_offset_in_page);
 		loff_t total_remaining_bytes = ((offset + size) - pos);
 
 		if (fatal_signal_pending(current)) {
@@ -165,7 +165,7 @@
 			 * Fill in zero values to the end of the page */
 			memset(((char *)ecryptfs_page_virt
 				+ start_offset_in_page), 0,
-				PAGE_CACHE_SIZE - start_offset_in_page);
+				PAGE_SIZE - start_offset_in_page);
 		}
 
 		/* pos >= offset, we are now writing the data request */
@@ -186,7 +186,7 @@
 						ecryptfs_page,
 						start_offset_in_page,
 						data_offset);
-		page_cache_release(ecryptfs_page);
+		put_page(ecryptfs_page);
 		if (rc) {
 			printk(KERN_ERR "%s: Error encrypting "
 			       "page; rc = [%d]\n", __func__, rc);
@@ -262,7 +262,7 @@
 	loff_t offset;
 	int rc;
 
-	offset = ((((loff_t)page_index) << PAGE_CACHE_SHIFT) + offset_in_page);
+	offset = ((((loff_t)page_index) << PAGE_SHIFT) + offset_in_page);
 	virt = kmap(page_for_ecryptfs);
 	rc = ecryptfs_read_lower(virt, offset, size, ecryptfs_inode);
 	if (rc > 0)