[PATCH 10/71] drivers/misc: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

From: Kirill A. Shutemov
Date: Sun Mar 20 2016 - 15:02:24 EST


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 <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/ibmasm/ibmasmfs.c | 4 ++--
drivers/misc/vmw_vmci/vmci_queue_pair.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/ibmasm/ibmasmfs.c b/drivers/misc/ibmasm/ibmasmfs.c
index e8b933111e0d..9c677f3f3c26 100644
--- a/drivers/misc/ibmasm/ibmasmfs.c
+++ b/drivers/misc/ibmasm/ibmasmfs.c
@@ -116,8 +116,8 @@ static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent)
{
struct inode *root;

- sb->s_blocksize = PAGE_CACHE_SIZE;
- sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_blocksize = PAGE_SIZE;
+ sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = IBMASMFS_MAGIC;
sb->s_op = &ibmasmfs_s_ops;
sb->s_time_gran = 1;
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index f42d9c4e4561..f84a4275ca29 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -728,7 +728,7 @@ static void qp_release_pages(struct page **pages,
if (dirty)
set_page_dirty(pages[i]);

- page_cache_release(pages[i]);
+ put_page(pages[i]);
pages[i] = NULL;
}
}
--
2.7.0