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>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Richard Weinberger <[email protected]>
---
 fs/hostfs/hostfs_kern.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index d1abbee281d1..7016653f3e41 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -410,12 +410,12 @@ static int hostfs_writepage(struct page *page, struct 
writeback_control *wbc)
        struct inode *inode = mapping->host;
        char *buffer;
        loff_t base = page_offset(page);
-       int count = PAGE_CACHE_SIZE;
-       int end_index = inode->i_size >> PAGE_CACHE_SHIFT;
+       int count = PAGE_SIZE;
+       int end_index = inode->i_size >> PAGE_SHIFT;
        int err;
 
        if (page->index >= end_index)
-               count = inode->i_size & (PAGE_CACHE_SIZE-1);
+               count = inode->i_size & (PAGE_SIZE-1);
 
        buffer = kmap(page);
 
@@ -447,7 +447,7 @@ static int hostfs_readpage(struct file *file, struct page 
*page)
 
        buffer = kmap(page);
        bytes_read = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer,
-                       PAGE_CACHE_SIZE);
+                       PAGE_SIZE);
        if (bytes_read < 0) {
                ClearPageUptodate(page);
                SetPageError(page);
@@ -455,7 +455,7 @@ static int hostfs_readpage(struct file *file, struct page 
*page)
                goto out;
        }
 
-       memset(buffer + bytes_read, 0, PAGE_CACHE_SIZE - bytes_read);
+       memset(buffer + bytes_read, 0, PAGE_SIZE - bytes_read);
 
        ClearPageError(page);
        SetPageUptodate(page);
@@ -471,7 +471,7 @@ static int hostfs_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;
 
        *pagep = grab_cache_page_write_begin(mapping, index, flags);
        if (!*pagep)
@@ -485,14 +485,14 @@ static int hostfs_write_end(struct file *file, struct 
address_space *mapping,
 {
        struct inode *inode = mapping->host;
        void *buffer;
-       unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+       unsigned from = pos & (PAGE_SIZE - 1);
        int err;
 
        buffer = kmap(page);
        err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied);
        kunmap(page);
 
-       if (!PageUptodate(page) && err == PAGE_CACHE_SIZE)
+       if (!PageUptodate(page) && err == PAGE_SIZE)
                SetPageUptodate(page);
 
        /*
@@ -502,7 +502,7 @@ static int hostfs_write_end(struct file *file, struct 
address_space *mapping,
        if (err > 0 && (pos > inode->i_size))
                inode->i_size = pos;
        unlock_page(page);
-       page_cache_release(page);
+       put_page(page);
 
        return err;
 }
-- 
2.7.0

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