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>

13 files changed, 51 insertions, 51 deletions

diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 0cea9b9..2c26184 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -181,11 +181,11 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
 			in = min(bytes, msblk->devblksize - offset);
 			bytes -= in;
 			while (in) {
-				if (pg_offset == PAGE_CACHE_SIZE) {
+				if (pg_offset == PAGE_SIZE) {
 					data = squashfs_next_page(output);
 					pg_offset = 0;
 				}
-				avail = min_t(int, in, PAGE_CACHE_SIZE -
+				avail = min_t(int, in, PAGE_SIZE -
 						pg_offset);
 				memcpy(data + pg_offset, bh[k]->b_data + offset,
 						avail);
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c
index 1cb70a0..27e501a 100644
--- a/fs/squashfs/cache.c
+++ b/fs/squashfs/cache.c
@@ -255,7 +255,7 @@ struct squashfs_cache *squashfs_cache_init(char *name, int entries,
 	cache->unused = entries;
 	cache->entries = entries;
 	cache->block_size = block_size;
-	cache->pages = block_size >> PAGE_CACHE_SHIFT;
+	cache->pages = block_size >> PAGE_SHIFT;
 	cache->pages = cache->pages ? cache->pages : 1;
 	cache->name = name;
 	cache->num_waiters = 0;
@@ -275,7 +275,7 @@ struct squashfs_cache *squashfs_cache_init(char *name, int entries,
 		}
 
 		for (j = 0; j < cache->pages; j++) {
-			entry->data[j] = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+			entry->data[j] = kmalloc(PAGE_SIZE, GFP_KERNEL);
 			if (entry->data[j] == NULL) {
 				ERROR("Failed to allocate %s buffer\n", name);
 				goto cleanup;
@@ -314,10 +314,10 @@ int squashfs_copy_data(void *buffer, struct squashfs_cache_entry *entry,
 		return min(length, entry->length - offset);
 
 	while (offset < entry->length) {
-		void *buff = entry->data[offset / PAGE_CACHE_SIZE]
-				+ (offset % PAGE_CACHE_SIZE);
+		void *buff = entry->data[offset / PAGE_SIZE]
+				+ (offset % PAGE_SIZE);
 		int bytes = min_t(int, entry->length - offset,
-				PAGE_CACHE_SIZE - (offset % PAGE_CACHE_SIZE));
+				PAGE_SIZE - (offset % PAGE_SIZE));
 
 		if (bytes >= remaining) {
 			memcpy(buffer, buff, remaining);
@@ -415,7 +415,7 @@ struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *sb,
  */
 void *squashfs_read_table(struct super_block *sb, u64 block, int length)
 {
-	int pages = (length + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	int pages = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	int i, res;
 	void *table, *buffer, **data;
 	struct squashfs_page_actor *actor;
@@ -436,7 +436,7 @@ void *squashfs_read_table(struct super_block *sb, u64 block, int length)
 		goto failed2;
 	}
 
-	for (i = 0; i < pages; i++, buffer += PAGE_CACHE_SIZE)
+	for (i = 0; i < pages; i++, buffer += PAGE_SIZE)
 		data[i] = buffer;
 
 	res = squashfs_read_data(sb, block, length |
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index e9034bf..d2bc136 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -102,7 +102,7 @@ static void *get_comp_opts(struct super_block *sb, unsigned short flags)
 	 * Read decompressor specific options from file system if present
 	 */
 	if (SQUASHFS_COMP_OPTS(flags)) {
-		buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+		buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
 		if (buffer == NULL) {
 			comp_opts = ERR_PTR(-ENOMEM);
 			goto out;
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index e5c9689..437de9e 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -175,7 +175,7 @@ static long long read_indexes(struct super_block *sb, int n,
 {
 	int err, i;
 	long long block = 0;
-	__le32 *blist = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+	__le32 *blist = kmalloc(PAGE_SIZE, GFP_KERNEL);
 
 	if (blist == NULL) {
 		ERROR("read_indexes: Failed to allocate block_list\n");
@@ -183,7 +183,7 @@ static long long read_indexes(struct super_block *sb, int n,
 	}
 
 	while (n) {
-		int blocks = min_t(int, n, PAGE_CACHE_SIZE >> 2);
+		int blocks = min_t(int, n, PAGE_SIZE >> 2);
 
 		err = squashfs_read_metadata(sb, blist, start_block,
 				offset, blocks << 2);
@@ -377,7 +377,7 @@ void squashfs_copy_cache(struct page *page, struct squashfs_cache_entry *buffer,
 	struct inode *inode = page->mapping->host;
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
 	void *pageaddr;
-	int i, mask = (1 << (msblk->block_log - PAGE_CACHE_SHIFT)) - 1;
+	int i, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
 	int start_index = page->index & ~mask, end_index = start_index | mask;
 
 	/*
@@ -387,9 +387,9 @@ void squashfs_copy_cache(struct page *page, struct squashfs_cache_entry *buffer,
 	 * been called to fill.
 	 */
 	for (i = start_index; i <= end_index && bytes > 0; i++,
-			bytes -= PAGE_CACHE_SIZE, offset += PAGE_CACHE_SIZE) {
+			bytes -= PAGE_SIZE, offset += PAGE_SIZE) {
 		struct page *push_page;
-		int avail = buffer ? min_t(int, bytes, PAGE_CACHE_SIZE) : 0;
+		int avail = buffer ? min_t(int, bytes, PAGE_SIZE) : 0;
 
 		TRACE("bytes %d, i %d, available_bytes %d\n", bytes, i, avail);
 
@@ -404,14 +404,14 @@ void squashfs_copy_cache(struct page *page, struct squashfs_cache_entry *buffer,
 
 		pageaddr = kmap_atomic(push_page);
 		squashfs_copy_data(pageaddr, buffer, offset, avail);
-		memset(pageaddr + avail, 0, PAGE_CACHE_SIZE - avail);
+		memset(pageaddr + avail, 0, PAGE_SIZE - avail);
 		kunmap_atomic(pageaddr);
 		flush_dcache_page(push_page);
 		SetPageUptodate(push_page);
 skip_page:
 		unlock_page(push_page);
 		if (i != page->index)
-			page_cache_release(push_page);
+			put_page(push_page);
 	}
 }
 
@@ -454,7 +454,7 @@ static int squashfs_readpage(struct file *file, struct page *page)
 {
 	struct inode *inode = page->mapping->host;
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
-	int index = page->index >> (msblk->block_log - PAGE_CACHE_SHIFT);
+	int index = page->index >> (msblk->block_log - PAGE_SHIFT);
 	int file_end = i_size_read(inode) >> msblk->block_log;
 	int res;
 	void *pageaddr;
@@ -462,8 +462,8 @@ static int squashfs_readpage(struct file *file, struct page *page)
 	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
 				page->index, squashfs_i(inode)->start);
 
-	if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
-					PAGE_CACHE_SHIFT))
+	if (page->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >>
+					PAGE_SHIFT))
 		goto out;
 
 	if (index < file_end || squashfs_i(inode)->fragment_block ==
@@ -487,7 +487,7 @@ error_out:
 	SetPageError(page);
 out:
 	pageaddr = kmap_atomic(page);
-	memset(pageaddr, 0, PAGE_CACHE_SIZE);
+	memset(pageaddr, 0, PAGE_SIZE);
 	kunmap_atomic(pageaddr);
 	flush_dcache_page(page);
 	if (!PageError(page))
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c
index 43e7a7e..cb485d8 100644
--- a/fs/squashfs/file_direct.c
+++ b/fs/squashfs/file_direct.c
@@ -30,8 +30,8 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize)
 	struct inode *inode = target_page->mapping->host;
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
 
-	int file_end = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
-	int mask = (1 << (msblk->block_log - PAGE_CACHE_SHIFT)) - 1;
+	int file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT;
+	int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
 	int start_index = target_page->index & ~mask;
 	int end_index = start_index | mask;
 	int i, n, pages, missing_pages, bytes, res = -ENOMEM;
@@ -68,7 +68,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize)
 
 		if (PageUptodate(page[i])) {
 			unlock_page(page[i]);
-			page_cache_release(page[i]);
+			put_page(page[i]);
 			page[i] = NULL;
 			missing_pages++;
 		}
@@ -96,10 +96,10 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize)
 		goto mark_errored;
 
 	/* Last page may have trailing bytes not filled */
-	bytes = res % PAGE_CACHE_SIZE;
+	bytes = res % PAGE_SIZE;
 	if (bytes) {
 		pageaddr = kmap_atomic(page[pages - 1]);
-		memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
+		memset(pageaddr + bytes, 0, PAGE_SIZE - bytes);
 		kunmap_atomic(pageaddr);
 	}
 
@@ -109,7 +109,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize)
 		SetPageUptodate(page[i]);
 		unlock_page(page[i]);
 		if (page[i] != target_page)
-			page_cache_release(page[i]);
+			put_page(page[i]);
 	}
 
 	kfree(actor);
@@ -127,7 +127,7 @@ mark_errored:
 		flush_dcache_page(page[i]);
 		SetPageError(page[i]);
 		unlock_page(page[i]);
-		page_cache_release(page[i]);
+		put_page(page[i]);
 	}
 
 out:
@@ -153,21 +153,21 @@ static int squashfs_read_cache(struct page *target_page, u64 block, int bsize,
 	}
 
 	for (n = 0; n < pages && bytes > 0; n++,
-			bytes -= PAGE_CACHE_SIZE, offset += PAGE_CACHE_SIZE) {
-		int avail = min_t(int, bytes, PAGE_CACHE_SIZE);
+			bytes -= PAGE_SIZE, offset += PAGE_SIZE) {
+		int avail = min_t(int, bytes, PAGE_SIZE);
 
 		if (page[n] == NULL)
 			continue;
 
 		pageaddr = kmap_atomic(page[n]);
 		squashfs_copy_data(pageaddr, buffer, offset, avail);
-		memset(pageaddr + avail, 0, PAGE_CACHE_SIZE - avail);
+		memset(pageaddr + avail, 0, PAGE_SIZE - avail);
 		kunmap_atomic(pageaddr);
 		flush_dcache_page(page[n]);
 		SetPageUptodate(page[n]);
 		unlock_page(page[n]);
 		if (page[n] != target_page)
-			page_cache_release(page[n]);
+			put_page(page[n]);
 	}
 
 out:
diff --git a/fs/squashfs/lz4_wrapper.c b/fs/squashfs/lz4_wrapper.c
index c31e2bc..ff4468b 100644
--- a/fs/squashfs/lz4_wrapper.c
+++ b/fs/squashfs/lz4_wrapper.c
@@ -117,13 +117,13 @@ static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm,
 	data = squashfs_first_page(output);
 	buff = stream->output;
 	while (data) {
-		if (bytes <= PAGE_CACHE_SIZE) {
+		if (bytes <= PAGE_SIZE) {
 			memcpy(data, buff, bytes);
 			break;
 		}
-		memcpy(data, buff, PAGE_CACHE_SIZE);
-		buff += PAGE_CACHE_SIZE;
-		bytes -= PAGE_CACHE_SIZE;
+		memcpy(data, buff, PAGE_SIZE);
+		buff += PAGE_SIZE;
+		bytes -= PAGE_SIZE;
 		data = squashfs_next_page(output);
 	}
 	squashfs_finish_page(output);
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
index 244b9fb..934c17e 100644
--- a/fs/squashfs/lzo_wrapper.c
+++ b/fs/squashfs/lzo_wrapper.c
@@ -102,13 +102,13 @@ static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
 	data = squashfs_first_page(output);
 	buff = stream->output;
 	while (data) {
-		if (bytes <= PAGE_CACHE_SIZE) {
+		if (bytes <= PAGE_SIZE) {
 			memcpy(data, buff, bytes);
 			break;
 		} else {
-			memcpy(data, buff, PAGE_CACHE_SIZE);
-			buff += PAGE_CACHE_SIZE;
-			bytes -= PAGE_CACHE_SIZE;
+			memcpy(data, buff, PAGE_SIZE);
+			buff += PAGE_SIZE;
+			bytes -= PAGE_SIZE;
 			data = squashfs_next_page(output);
 		}
 	}
diff --git a/fs/squashfs/page_actor.c b/fs/squashfs/page_actor.c
index 5a1c11f..9b7b1b6 100644
--- a/fs/squashfs/page_actor.c
+++ b/fs/squashfs/page_actor.c
@@ -48,7 +48,7 @@ struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
 	if (actor == NULL)
 		return NULL;
 
-	actor->length = length ? : pages * PAGE_CACHE_SIZE;
+	actor->length = length ? : pages * PAGE_SIZE;
 	actor->buffer = buffer;
 	actor->pages = pages;
 	actor->next_page = 0;
@@ -88,7 +88,7 @@ struct squashfs_page_actor *squashfs_page_actor_init_special(struct page **page,
 	if (actor == NULL)
 		return NULL;
 
-	actor->length = length ? : pages * PAGE_CACHE_SIZE;
+	actor->length = length ? : pages * PAGE_SIZE;
 	actor->page = page;
 	actor->pages = pages;
 	actor->next_page = 0;
diff --git a/fs/squashfs/page_actor.h b/fs/squashfs/page_actor.h
index 26dd820..98537ea 100644
--- a/fs/squashfs/page_actor.h
+++ b/fs/squashfs/page_actor.h
@@ -24,7 +24,7 @@ static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
 	if (actor == NULL)
 		return NULL;
 
-	actor->length = length ? : pages * PAGE_CACHE_SIZE;
+	actor->length = length ? : pages * PAGE_SIZE;
 	actor->page = page;
 	actor->pages = pages;
 	actor->next_page = 0;
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 5e79bfa..cf01e15 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -152,7 +152,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 	 * Check the system page size is not larger than the filesystem
 	 * block size (by default 128K).  This is currently not supported.
 	 */
-	if (PAGE_CACHE_SIZE > msblk->block_size) {
+	if (PAGE_SIZE > msblk->block_size) {
 		ERROR("Page size > filesystem block size (%d).  This is "
 			"currently not supported!\n", msblk->block_size);
 		goto failed_mount;
diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c
index dbcc2f5..d688ef4 100644
--- a/fs/squashfs/symlink.c
+++ b/fs/squashfs/symlink.c
@@ -48,10 +48,10 @@ static int squashfs_symlink_readpage(struct file *file, struct page *page)
 	struct inode *inode = page->mapping->host;
 	struct super_block *sb = inode->i_sb;
 	struct squashfs_sb_info *msblk = sb->s_fs_info;
-	int index = page->index << PAGE_CACHE_SHIFT;
+	int index = page->index << PAGE_SHIFT;
 	u64 block = squashfs_i(inode)->start;
 	int offset = squashfs_i(inode)->offset;
-	int length = min_t(int, i_size_read(inode) - index, PAGE_CACHE_SIZE);
+	int length = min_t(int, i_size_read(inode) - index, PAGE_SIZE);
 	int bytes, copied;
 	void *pageaddr;
 	struct squashfs_cache_entry *entry;
@@ -94,7 +94,7 @@ static int squashfs_symlink_readpage(struct file *file, struct page *page)
 		copied = squashfs_copy_data(pageaddr + bytes, entry, offset,
 								length - bytes);
 		if (copied == length - bytes)
-			memset(pageaddr + length, 0, PAGE_CACHE_SIZE - length);
+			memset(pageaddr + length, 0, PAGE_SIZE - length);
 		else
 			block = entry->next_index;
 		kunmap_atomic(pageaddr);
diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c
index c609624..6bfaef7 100644
--- a/fs/squashfs/xz_wrapper.c
+++ b/fs/squashfs/xz_wrapper.c
@@ -141,7 +141,7 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
 	stream->buf.in_pos = 0;
 	stream->buf.in_size = 0;
 	stream->buf.out_pos = 0;
-	stream->buf.out_size = PAGE_CACHE_SIZE;
+	stream->buf.out_size = PAGE_SIZE;
 	stream->buf.out = squashfs_first_page(output);
 
 	do {
@@ -158,7 +158,7 @@ static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
 			stream->buf.out = squashfs_next_page(output);
 			if (stream->buf.out != NULL) {
 				stream->buf.out_pos = 0;
-				total += PAGE_CACHE_SIZE;
+				total += PAGE_SIZE;
 			}
 		}
 
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 8727cab..2ec24d1 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -69,7 +69,7 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
 	int zlib_err, zlib_init = 0, k = 0;
 	z_stream *stream = strm;
 
-	stream->avail_out = PAGE_CACHE_SIZE;
+	stream->avail_out = PAGE_SIZE;
 	stream->next_out = squashfs_first_page(output);
 	stream->avail_in = 0;
 
@@ -85,7 +85,7 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm,
 		if (stream->avail_out == 0) {
 			stream->next_out = squashfs_next_page(output);
 			if (stream->next_out != NULL)
-				stream->avail_out = PAGE_CACHE_SIZE;
+				stream->avail_out = PAGE_SIZE;
 		}
 
 		if (!zlib_init) {