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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)

Kirill A. Shutemov committed 10 years ago

Commit 09cbfea1 parent c05c2ec381 files · +2722 −2721Browse files

Showing the changes to include/linux/buffer_head.h (1 of 381 files). Show all

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include/linux/buffer_head.h+2−2
@@ -43,7 +43,7 @@ enum bh_state_bits { · 42 unmodified lines
4343 */
4444 };
4545
46−#define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512)
46+#define MAX_BUF_PER_PAGE (PAGE_SIZE / 512)
4747
4848 struct page;
4949 struct buffer_head;
@@ -263,7 +263,7 @@ void buffer_init(void); · 213 unmodified lines
263263 static inline void attach_page_buffers(struct page *page,
264264 struct buffer_head *head)
265265 {
266− page_cache_get(page);
266+ get_page(page);
267267 SetPagePrivate(page);
268268 set_page_private(page, (unsigned long)head);
269269 }