[PATCH 49/71] ncpfs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

From: Kirill A. Shutemov
Date: Sun Mar 20 2016 - 14:50:21 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: Petr Vandrovec <petr@xxxxxxxxxxxxxx>
---
fs/ncpfs/dir.c | 10 +++++-----
fs/ncpfs/ncplib_kernel.h | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index b7f8eaeea5d8..bfdad003ee56 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -510,7 +510,7 @@ static int ncp_readdir(struct file *file, struct dir_context *ctx)
kunmap(ctl.page);
SetPageUptodate(ctl.page);
unlock_page(ctl.page);
- page_cache_release(ctl.page);
+ put_page(ctl.page);
ctl.page = NULL;
}
ctl.idx = 0;
@@ -520,7 +520,7 @@ invalid_cache:
if (ctl.page) {
kunmap(ctl.page);
unlock_page(ctl.page);
- page_cache_release(ctl.page);
+ put_page(ctl.page);
ctl.page = NULL;
}
ctl.cache = cache;
@@ -554,14 +554,14 @@ finished:
kunmap(ctl.page);
SetPageUptodate(ctl.page);
unlock_page(ctl.page);
- page_cache_release(ctl.page);
+ put_page(ctl.page);
}
if (page) {
cache->head = ctl.head;
kunmap(page);
SetPageUptodate(page);
unlock_page(page);
- page_cache_release(page);
+ put_page(page);
}
out:
return result;
@@ -649,7 +649,7 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx,
kunmap(ctl.page);
SetPageUptodate(ctl.page);
unlock_page(ctl.page);
- page_cache_release(ctl.page);
+ put_page(ctl.page);
}
ctl.cache = NULL;
ctl.idx -= NCP_DIRCACHE_SIZE;
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index 5233fbc1747a..17cfb743b5bf 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -191,7 +191,7 @@ struct ncp_cache_head {
int eof;
};

-#define NCP_DIRCACHE_SIZE ((int)(PAGE_CACHE_SIZE/sizeof(struct dentry *)))
+#define NCP_DIRCACHE_SIZE ((int)(PAGE_SIZE/sizeof(struct dentry *)))
union ncp_dir_cache {
struct ncp_cache_head head;
struct dentry *dentry[NCP_DIRCACHE_SIZE];
--
2.7.0