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>

7 files changed, 57 insertions, 57 deletions

diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index a709d80..cc26f8f 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -64,7 +64,7 @@ static void writeseg_end_io(struct bio *bio)
 
 	bio_for_each_segment_all(bvec, bio, i) {
 		end_page_writeback(bvec->bv_page);
-		page_cache_release(bvec->bv_page);
+		put_page(bvec->bv_page);
 	}
 	bio_put(bio);
 	if (atomic_dec_and_test(&super->s_pending_writes))
diff --git a/fs/logfs/dev_mtd.c b/fs/logfs/dev_mtd.c
index 9c50144..b76a62b 100644
--- a/fs/logfs/dev_mtd.c
+++ b/fs/logfs/dev_mtd.c
@@ -46,9 +46,9 @@ static int loffs_mtd_write(struct super_block *sb, loff_t ofs, size_t len,
 
 	BUG_ON((ofs >= mtd->size) || (len > mtd->size - ofs));
 	BUG_ON(ofs != (ofs >> super->s_writeshift) << super->s_writeshift);
-	BUG_ON(len > PAGE_CACHE_SIZE);
-	page_start = ofs & PAGE_CACHE_MASK;
-	page_end = PAGE_CACHE_ALIGN(ofs + len) - 1;
+	BUG_ON(len > PAGE_SIZE);
+	page_start = ofs & PAGE_MASK;
+	page_end = PAGE_ALIGN(ofs + len) - 1;
 	ret = mtd_write(mtd, ofs, len, &retlen, buf);
 	if (ret || (retlen != len))
 		return -EIO;
@@ -82,7 +82,7 @@ static int logfs_mtd_erase_mapping(struct super_block *sb, loff_t ofs,
 		if (!page)
 			continue;
 		memset(page_address(page), 0xFF, PAGE_SIZE);
-		page_cache_release(page);
+		put_page(page);
 	}
 	return 0;
 }
@@ -195,7 +195,7 @@ static int __logfs_mtd_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
 		err = loffs_mtd_write(sb, page->index << PAGE_SHIFT, PAGE_SIZE,
 					page_address(page));
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		if (err)
 			return err;
 	}
diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index 542468e..ddbed2b 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -183,7 +183,7 @@ static struct page *logfs_get_dd_page(struct inode *dir, struct dentry *dentry)
 		if (name->len != be16_to_cpu(dd->namelen) ||
 				memcmp(name->name, dd->name, name->len)) {
 			kunmap_atomic(dd);
-			page_cache_release(page);
+			put_page(page);
 			continue;
 		}
 
@@ -238,7 +238,7 @@ static int logfs_unlink(struct inode *dir, struct dentry *dentry)
 		return PTR_ERR(page);
 	}
 	index = page->index;
-	page_cache_release(page);
+	put_page(page);
 
 	mutex_lock(&super->s_dirop_mutex);
 	logfs_add_transaction(dir, ta);
@@ -316,7 +316,7 @@ static int logfs_readdir(struct file *file, struct dir_context *ctx)
 				be16_to_cpu(dd->namelen),
 				be64_to_cpu(dd->ino), dd->type);
 		kunmap(page);
-		page_cache_release(page);
+		put_page(page);
 		if (full)
 			break;
 	}
@@ -349,7 +349,7 @@ static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry,
 	dd = kmap_atomic(page);
 	ino = be64_to_cpu(dd->ino);
 	kunmap_atomic(dd);
-	page_cache_release(page);
+	put_page(page);
 
 	inode = logfs_iget(dir->i_sb, ino);
 	if (IS_ERR(inode))
@@ -392,7 +392,7 @@ static int logfs_write_dir(struct inode *dir, struct dentry *dentry,
 
 		err = logfs_write_buf(dir, page, WF_LOCK);
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		if (!err)
 			grow_dir(dir, index);
 		return err;
@@ -561,7 +561,7 @@ static int logfs_get_dd(struct inode *dir, struct dentry *dentry,
 	map = kmap_atomic(page);
 	memcpy(dd, map, sizeof(*dd));
 	kunmap_atomic(map);
-	page_cache_release(page);
+	put_page(page);
 	return 0;
 }
 
diff --git a/fs/logfs/file.c b/fs/logfs/file.c
index 61eaeb1..f01ddfb 100644
--- a/fs/logfs/file.c
+++ b/fs/logfs/file.c
@@ -15,21 +15,21 @@ static int logfs_write_begin(struct file *file, struct address_space *mapping,
 {
 	struct inode *inode = mapping->host;
 	struct page *page;
-	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+	pgoff_t index = pos >> PAGE_SHIFT;
 
 	page = grab_cache_page_write_begin(mapping, index, flags);
 	if (!page)
 		return -ENOMEM;
 	*pagep = page;
 
-	if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
+	if ((len == PAGE_SIZE) || PageUptodate(page))
 		return 0;
-	if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
-		unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+	if ((pos & PAGE_MASK) >= i_size_read(inode)) {
+		unsigned start = pos & (PAGE_SIZE - 1);
 		unsigned end = start + len;
 
 		/* Reading beyond i_size is simple: memset to zero */
-		zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
+		zero_user_segments(page, 0, start, end, PAGE_SIZE);
 		return 0;
 	}
 	return logfs_readpage_nolock(page);
@@ -41,11 +41,11 @@ static int logfs_write_end(struct file *file, struct address_space *mapping,
 {
 	struct inode *inode = mapping->host;
 	pgoff_t index = page->index;
-	unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+	unsigned start = pos & (PAGE_SIZE - 1);
 	unsigned end = start + copied;
 	int ret = 0;
 
-	BUG_ON(PAGE_CACHE_SIZE != inode->i_sb->s_blocksize);
+	BUG_ON(PAGE_SIZE != inode->i_sb->s_blocksize);
 	BUG_ON(page->index > I3_BLOCKS);
 
 	if (copied < len) {
@@ -61,8 +61,8 @@ static int logfs_write_end(struct file *file, struct address_space *mapping,
 	if (copied == 0)
 		goto out; /* FIXME: do we need to update inode? */
 
-	if (i_size_read(inode) < (index << PAGE_CACHE_SHIFT) + end) {
-		i_size_write(inode, (index << PAGE_CACHE_SHIFT) + end);
+	if (i_size_read(inode) < (index << PAGE_SHIFT) + end) {
+		i_size_write(inode, (index << PAGE_SHIFT) + end);
 		mark_inode_dirty_sync(inode);
 	}
 
@@ -75,7 +75,7 @@ static int logfs_write_end(struct file *file, struct address_space *mapping,
 	}
 out:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return ret ? ret : copied;
 }
 
@@ -118,7 +118,7 @@ static int logfs_writepage(struct page *page, struct writeback_control *wbc)
 {
 	struct inode *inode = page->mapping->host;
 	loff_t i_size = i_size_read(inode);
-	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	pgoff_t end_index = i_size >> PAGE_SHIFT;
 	unsigned offset;
 	u64 bix;
 	level_t level;
@@ -142,7 +142,7 @@ static int logfs_writepage(struct page *page, struct writeback_control *wbc)
 		return __logfs_writepage(page);
 
 	 /* Is the page fully outside i_size? (truncate in progress) */
-	offset = i_size & (PAGE_CACHE_SIZE-1);
+	offset = i_size & (PAGE_SIZE-1);
 	if (bix > end_index || offset == 0) {
 		unlock_page(page);
 		return 0; /* don't care */
@@ -155,7 +155,7 @@ static int logfs_writepage(struct page *page, struct writeback_control *wbc)
 	 * the  page size, the remaining memory is zeroed when mapped, and
 	 * writes to that region are not written out to the file."
 	 */
-	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+	zero_user_segment(page, offset, PAGE_SIZE);
 	return __logfs_writepage(page);
 }
 
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 20973c9..3fb8c6d 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -281,7 +281,7 @@ static struct page *logfs_get_read_page(struct inode *inode, u64 bix,
 static void logfs_put_read_page(struct page *page)
 {
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 }
 
 static void logfs_lock_write_page(struct page *page)
@@ -323,7 +323,7 @@ repeat:
 			return NULL;
 		err = add_to_page_cache_lru(page, mapping, index, GFP_NOFS);
 		if (unlikely(err)) {
-			page_cache_release(page);
+			put_page(page);
 			if (err == -EEXIST)
 				goto repeat;
 			return NULL;
@@ -342,7 +342,7 @@ static void logfs_unlock_write_page(struct page *page)
 static void logfs_put_write_page(struct page *page)
 {
 	logfs_unlock_write_page(page);
-	page_cache_release(page);
+	put_page(page);
 }
 
 static struct page *logfs_get_page(struct inode *inode, u64 bix, level_t level,
@@ -562,7 +562,7 @@ static void indirect_free_block(struct super_block *sb,
 
 	if (PagePrivate(page)) {
 		ClearPagePrivate(page);
-		page_cache_release(page);
+		put_page(page);
 		set_page_private(page, 0);
 	}
 	__free_block(sb, block);
@@ -655,7 +655,7 @@ static void alloc_data_block(struct inode *inode, struct page *page)
 	block->page = page;
 
 	SetPagePrivate(page);
-	page_cache_get(page);
+	get_page(page);
 	set_page_private(page, (unsigned long) block);
 
 	block->ops = &indirect_block_ops;
@@ -709,7 +709,7 @@ static u64 block_get_pointer(struct page *page, int index)
 
 static int logfs_read_empty(struct page *page)
 {
-	zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+	zero_user_segment(page, 0, PAGE_SIZE);
 	return 0;
 }
 
@@ -1660,7 +1660,7 @@ static int truncate_data_block(struct inode *inode, struct page *page,
 	if (err)
 		return err;
 
-	zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE);
+	zero_user_segment(page, size - pageofs, PAGE_SIZE);
 	return logfs_segment_write(inode, page, shadow);
 }
 
@@ -1919,7 +1919,7 @@ static void move_page_to_inode(struct inode *inode, struct page *page)
 	block->page = NULL;
 	if (PagePrivate(page)) {
 		ClearPagePrivate(page);
-		page_cache_release(page);
+		put_page(page);
 		set_page_private(page, 0);
 	}
 }
@@ -1940,7 +1940,7 @@ static void move_inode_to_page(struct page *page, struct inode *inode)
 
 	if (!PagePrivate(page)) {
 		SetPagePrivate(page);
-		page_cache_get(page);
+		get_page(page);
 		set_page_private(page, (unsigned long) block);
 	}
 
@@ -1971,7 +1971,7 @@ int logfs_read_inode(struct inode *inode)
 	logfs_disk_to_inode(di, inode);
 	kunmap_atomic(di);
 	move_page_to_inode(inode, page);
-	page_cache_release(page);
+	put_page(page);
 	return 0;
 }
 
diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c
index d270e4b..1efd605 100644
--- a/fs/logfs/segment.c
+++ b/fs/logfs/segment.c
@@ -90,9 +90,9 @@ int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
 
 		if (!PagePrivate(page)) {
 			SetPagePrivate(page);
-			page_cache_get(page);
+			get_page(page);
 		}
-		page_cache_release(page);
+		put_page(page);
 
 		buf += copylen;
 		len -= copylen;
@@ -117,9 +117,9 @@ static void pad_partial_page(struct logfs_area *area)
 		memset(page_address(page) + offset, 0xff, len);
 		if (!PagePrivate(page)) {
 			SetPagePrivate(page);
-			page_cache_get(page);
+			get_page(page);
 		}
-		page_cache_release(page);
+		put_page(page);
 	}
 }
 
@@ -129,20 +129,20 @@ static void pad_full_pages(struct logfs_area *area)
 	struct logfs_super *super = logfs_super(sb);
 	u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes);
 	u32 len = super->s_segsize - area->a_used_bytes;
-	pgoff_t index = PAGE_CACHE_ALIGN(ofs) >> PAGE_CACHE_SHIFT;
-	pgoff_t no_indizes = len >> PAGE_CACHE_SHIFT;
+	pgoff_t index = PAGE_ALIGN(ofs) >> PAGE_SHIFT;
+	pgoff_t no_indizes = len >> PAGE_SHIFT;
 	struct page *page;
 
 	while (no_indizes) {
 		page = get_mapping_page(sb, index, 0);
 		BUG_ON(!page); /* FIXME: reserve a pool */
 		SetPageUptodate(page);
-		memset(page_address(page), 0xff, PAGE_CACHE_SIZE);
+		memset(page_address(page), 0xff, PAGE_SIZE);
 		if (!PagePrivate(page)) {
 			SetPagePrivate(page);
-			page_cache_get(page);
+			get_page(page);
 		}
-		page_cache_release(page);
+		put_page(page);
 		index++;
 		no_indizes--;
 	}
@@ -411,7 +411,7 @@ int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf)
 		if (IS_ERR(page))
 			return PTR_ERR(page);
 		memcpy(buf, page_address(page) + offset, copylen);
-		page_cache_release(page);
+		put_page(page);
 
 		buf += copylen;
 		len -= copylen;
@@ -499,7 +499,7 @@ static void move_btree_to_page(struct inode *inode, struct page *page,
 
 	if (!PagePrivate(page)) {
 		SetPagePrivate(page);
-		page_cache_get(page);
+		get_page(page);
 		set_page_private(page, (unsigned long) block);
 	}
 	block->ops = &indirect_block_ops;
@@ -554,7 +554,7 @@ void move_page_to_btree(struct page *page)
 
 	if (PagePrivate(page)) {
 		ClearPagePrivate(page);
-		page_cache_release(page);
+		put_page(page);
 		set_page_private(page, 0);
 	}
 	block->ops = &btree_block_ops;
@@ -723,9 +723,9 @@ void freeseg(struct super_block *sb, u32 segno)
 			continue;
 		if (PagePrivate(page)) {
 			ClearPagePrivate(page);
-			page_cache_release(page);
+			put_page(page);
 		}
-		page_cache_release(page);
+		put_page(page);
 	}
 }
 
diff --git a/fs/logfs/super.c b/fs/logfs/super.c
index 5436029..5751082 100644
--- a/fs/logfs/super.c
+++ b/fs/logfs/super.c
@@ -48,7 +48,7 @@ void emergency_read_end(struct page *page)
 	if (page == emergency_page)
 		mutex_unlock(&emergency_mutex);
 	else
-		page_cache_release(page);
+		put_page(page);
 }
 
 static void dump_segfile(struct super_block *sb)
@@ -206,7 +206,7 @@ static int write_one_sb(struct super_block *sb,
 	logfs_set_segment_erased(sb, segno, ec, 0);
 	logfs_write_ds(sb, ds, segno, ec);
 	err = super->s_devops->write_sb(sb, page);
-	page_cache_release(page);
+	put_page(page);
 	return err;
 }
 
@@ -366,24 +366,24 @@ static struct page *find_super_block(struct super_block *sb)
 		return NULL;
 	last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]);
 	if (!last || IS_ERR(last)) {
-		page_cache_release(first);
+		put_page(first);
 		return NULL;
 	}
 
 	if (!logfs_check_ds(page_address(first))) {
-		page_cache_release(last);
+		put_page(last);
 		return first;
 	}
 
 	/* First one didn't work, try the second superblock */
 	if (!logfs_check_ds(page_address(last))) {
-		page_cache_release(first);
+		put_page(first);
 		return last;
 	}
 
 	/* Neither worked, sorry folks */
-	page_cache_release(first);
-	page_cache_release(last);
+	put_page(first);
+	put_page(last);
 	return NULL;
 }
 
@@ -425,7 +425,7 @@ static int __logfs_read_sb(struct super_block *sb)
 	super->s_data_levels = ds->ds_data_levels;
 	super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels
 		+ super->s_data_levels;
-	page_cache_release(page);
+	put_page(page);
 	return 0;
 }