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, 36 insertions, 36 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 9dde38f12c07..719924d6c706 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -348,7 +348,7 @@ static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from,
 		pgoff_t curr_index;
 
 		BUG_ON(req->inode != inode);
-		curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+		curr_index = req->misc.write.in.offset >> PAGE_SHIFT;
 		if (idx_from < curr_index + req->num_pages &&
 		    curr_index <= idx_to) {
 			found = true;
@@ -683,11 +683,11 @@ static void fuse_short_read(struct fuse_req *req, struct inode *inode,
 		 * present there.
 		 */
 		int i;
-		int start_idx = num_read >> PAGE_CACHE_SHIFT;
-		size_t off = num_read & (PAGE_CACHE_SIZE - 1);
+		int start_idx = num_read >> PAGE_SHIFT;
+		size_t off = num_read & (PAGE_SIZE - 1);
 
 		for (i = start_idx; i < req->num_pages; i++) {
-			zero_user_segment(req->pages[i], off, PAGE_CACHE_SIZE);
+			zero_user_segment(req->pages[i], off, PAGE_SIZE);
 			off = 0;
 		}
 	} else {
@@ -704,7 +704,7 @@ static int fuse_do_readpage(struct file *file, struct page *page)
 	struct fuse_req *req;
 	size_t num_read;
 	loff_t pos = page_offset(page);
-	size_t count = PAGE_CACHE_SIZE;
+	size_t count = PAGE_SIZE;
 	u64 attr_ver;
 	int err;
 
@@ -789,7 +789,7 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
 		else
 			SetPageError(page);
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 	}
 	if (req->ff)
 		fuse_file_put(req->ff, false);
@@ -800,7 +800,7 @@ static void fuse_send_readpages(struct fuse_req *req, struct file *file)
 	struct fuse_file *ff = file->private_data;
 	struct fuse_conn *fc = ff->fc;
 	loff_t pos = page_offset(req->pages[0]);
-	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
+	size_t count = req->num_pages << PAGE_SHIFT;
 
 	req->out.argpages = 1;
 	req->out.page_zeroing = 1;
@@ -836,7 +836,7 @@ static int fuse_readpages_fill(void *_data, struct page *page)
 
 	if (req->num_pages &&
 	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
-	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
+	     (req->num_pages + 1) * PAGE_SIZE > fc->max_read ||
 	     req->pages[req->num_pages - 1]->index + 1 != page->index)) {
 		int nr_alloc = min_t(unsigned, data->nr_pages,
 				     FUSE_MAX_PAGES_PER_REQ);
@@ -858,7 +858,7 @@ static int fuse_readpages_fill(void *_data, struct page *page)
 		return -EIO;
 	}
 
-	page_cache_get(page);
+	get_page(page);
 	req->pages[req->num_pages] = page;
 	req->page_descs[req->num_pages].length = PAGE_SIZE;
 	req->num_pages++;
@@ -1003,17 +1003,17 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
 	for (i = 0; i < req->num_pages; i++) {
 		struct page *page = req->pages[i];
 
-		if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
+		if (!req->out.h.error && !offset && count >= PAGE_SIZE)
 			SetPageUptodate(page);
 
-		if (count > PAGE_CACHE_SIZE - offset)
-			count -= PAGE_CACHE_SIZE - offset;
+		if (count > PAGE_SIZE - offset)
+			count -= PAGE_SIZE - offset;
 		else
 			count = 0;
 		offset = 0;
 
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 	}
 
 	return res;
@@ -1024,7 +1024,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
 			       struct iov_iter *ii, loff_t pos)
 {
 	struct fuse_conn *fc = get_fuse_conn(mapping->host);
-	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+	unsigned offset = pos & (PAGE_SIZE - 1);
 	size_t count = 0;
 	int err;
 
@@ -1034,8 +1034,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
 	do {
 		size_t tmp;
 		struct page *page;
-		pgoff_t index = pos >> PAGE_CACHE_SHIFT;
-		size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
+		pgoff_t index = pos >> PAGE_SHIFT;
+		size_t bytes = min_t(size_t, PAGE_SIZE - offset,
 				     iov_iter_count(ii));
 
 		bytes = min_t(size_t, bytes, fc->max_write - count);
@@ -1059,7 +1059,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
 		iov_iter_advance(ii, tmp);
 		if (!tmp) {
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 			bytes = min(bytes, iov_iter_single_seg_count(ii));
 			goto again;
 		}
@@ -1072,7 +1072,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
 		count += tmp;
 		pos += tmp;
 		offset += tmp;
-		if (offset == PAGE_CACHE_SIZE)
+		if (offset == PAGE_SIZE)
 			offset = 0;
 
 		if (!fc->big_writes)
@@ -1086,8 +1086,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req,
 static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
 {
 	return min_t(unsigned,
-		     ((pos + len - 1) >> PAGE_CACHE_SHIFT) -
-		     (pos >> PAGE_CACHE_SHIFT) + 1,
+		     ((pos + len - 1) >> PAGE_SHIFT) -
+		     (pos >> PAGE_SHIFT) + 1,
 		     FUSE_MAX_PAGES_PER_REQ);
 }
 
@@ -1205,8 +1205,8 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 			goto out;
 
 		invalidate_mapping_pages(file->f_mapping,
-					 pos >> PAGE_CACHE_SHIFT,
-					 endbyte >> PAGE_CACHE_SHIFT);
+					 pos >> PAGE_SHIFT,
+					 endbyte >> PAGE_SHIFT);
 
 		written += written_buffered;
 		iocb->ki_pos = pos + written_buffered;
@@ -1315,8 +1315,8 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 	size_t nmax = write ? fc->max_write : fc->max_read;
 	loff_t pos = *ppos;
 	size_t count = iov_iter_count(iter);
-	pgoff_t idx_from = pos >> PAGE_CACHE_SHIFT;
-	pgoff_t idx_to = (pos + count - 1) >> PAGE_CACHE_SHIFT;
+	pgoff_t idx_from = pos >> PAGE_SHIFT;
+	pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT;
 	ssize_t res = 0;
 	struct fuse_req *req;
 	int err = 0;
@@ -1466,7 +1466,7 @@ __acquires(fc->lock)
 {
 	struct fuse_inode *fi = get_fuse_inode(req->inode);
 	struct fuse_write_in *inarg = &req->misc.write.in;
-	__u64 data_size = req->num_pages * PAGE_CACHE_SIZE;
+	__u64 data_size = req->num_pages * PAGE_SIZE;
 
 	if (!fc->connected)
 		goto out_free;
@@ -1727,7 +1727,7 @@ static bool fuse_writepage_in_flight(struct fuse_req *new_req,
 	list_del(&new_req->writepages_entry);
 	list_for_each_entry(old_req, &fi->writepages, writepages_entry) {
 		BUG_ON(old_req->inode != new_req->inode);
-		curr_index = old_req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+		curr_index = old_req->misc.write.in.offset >> PAGE_SHIFT;
 		if (curr_index <= page->index &&
 		    page->index < curr_index + old_req->num_pages) {
 			found = true;
@@ -1742,7 +1742,7 @@ static bool fuse_writepage_in_flight(struct fuse_req *new_req,
 	new_req->num_pages = 1;
 	for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) {
 		BUG_ON(tmp->inode != new_req->inode);
-		curr_index = tmp->misc.write.in.offset >> PAGE_CACHE_SHIFT;
+		curr_index = tmp->misc.write.in.offset >> PAGE_SHIFT;
 		if (tmp->num_pages == 1 &&
 		    curr_index == page->index) {
 			old_req = tmp;
@@ -1799,7 +1799,7 @@ static int fuse_writepages_fill(struct page *page,
 
 	if (req && req->num_pages &&
 	    (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
-	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write ||
+	     (req->num_pages + 1) * PAGE_SIZE > fc->max_write ||
 	     data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) {
 		fuse_writepages_send(data);
 		data->req = NULL;
@@ -1924,7 +1924,7 @@ static int fuse_write_begin(struct file *file, struct address_space *mapping,
 		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 fuse_conn *fc = get_fuse_conn(file_inode(file));
 	struct page *page;
 	loff_t fsize;
@@ -1938,15 +1938,15 @@ static int fuse_write_begin(struct file *file, struct address_space *mapping,
 
 	fuse_wait_on_page_writeback(mapping->host, page->index);
 
-	if (PageUptodate(page) || len == PAGE_CACHE_SIZE)
+	if (PageUptodate(page) || len == PAGE_SIZE)
 		goto success;
 	/*
 	 * Check if the start this page comes after the end of file, in which
 	 * case the readpage can be optimized away.
 	 */
 	fsize = i_size_read(mapping->host);
-	if (fsize <= (pos & PAGE_CACHE_MASK)) {
-		size_t off = pos & ~PAGE_CACHE_MASK;
+	if (fsize <= (pos & PAGE_MASK)) {
+		size_t off = pos & ~PAGE_MASK;
 		if (off)
 			zero_user_segment(page, 0, off);
 		goto success;
@@ -1960,7 +1960,7 @@ success:
 
 cleanup:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 error:
 	return err;
 }
@@ -1973,16 +1973,16 @@ static int fuse_write_end(struct file *file, struct address_space *mapping,
 
 	if (!PageUptodate(page)) {
 		/* Zero any unwritten bytes at the end of the page */
-		size_t endoff = (pos + copied) & ~PAGE_CACHE_MASK;
+		size_t endoff = (pos + copied) & ~PAGE_MASK;
 		if (endoff)
-			zero_user_segment(page, endoff, PAGE_CACHE_SIZE);
+			zero_user_segment(page, endoff, PAGE_SIZE);
 		SetPageUptodate(page);
 	}
 
 	fuse_write_update_size(inode, pos + copied);
 	set_page_dirty(page);
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 
 	return copied;
 }