09cbfeaf1a
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>
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
#ifndef PAGE_ACTOR_H
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#define PAGE_ACTOR_H
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/*
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* Copyright (c) 2013
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* Phillip Lougher <phillip@squashfs.org.uk>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*/
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#ifndef CONFIG_SQUASHFS_FILE_DIRECT
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struct squashfs_page_actor {
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void **page;
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int pages;
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int length;
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int next_page;
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};
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static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
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int pages, int length)
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{
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struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
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if (actor == NULL)
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return NULL;
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actor->length = length ? : pages * PAGE_SIZE;
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actor->page = page;
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actor->pages = pages;
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actor->next_page = 0;
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return actor;
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}
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static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
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{
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actor->next_page = 1;
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return actor->page[0];
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}
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static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
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{
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return actor->next_page == actor->pages ? NULL :
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actor->page[actor->next_page++];
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}
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static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
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{
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/* empty */
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}
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#else
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struct squashfs_page_actor {
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union {
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void **buffer;
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struct page **page;
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};
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void *pageaddr;
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void *(*squashfs_first_page)(struct squashfs_page_actor *);
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void *(*squashfs_next_page)(struct squashfs_page_actor *);
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void (*squashfs_finish_page)(struct squashfs_page_actor *);
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int pages;
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int length;
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int next_page;
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};
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extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int);
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extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page
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**, int, int);
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static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
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{
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return actor->squashfs_first_page(actor);
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}
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static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
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{
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return actor->squashfs_next_page(actor);
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}
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static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
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{
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actor->squashfs_finish_page(actor);
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}
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#endif
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#endif
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