From 01f2705daf5a36208e69d7cf95db9c330f843af6 Mon Sep 17 00:00:00 2001 From: Nate Diller Date: Wed, 9 May 2007 02:35:07 -0700 Subject: fs: convert core functions to zero_user_page It's very common for file systems to need to zero part or all of a page, the simplist way is just to use kmap_atomic() and memset(). There's actually a library function in include/linux/highmem.h that does exactly that, but it's confusingly named memclear_highpage_flush(), which is descriptive of *how* it does the work rather than what the *purpose* is. So this patchset renames the function to zero_user_page(), and calls it from the various places that currently open code it. This first patch introduces the new function call, and converts all the core kernel callsites, both the open-coded ones and the old memclear_highpage_flush() ones. Following this patch is a series of conversions for each file system individually, per AKPM, and finally a patch deprecating the old call. The diffstat below shows the entire patchset. [akpm@linux-foundation.org: fix a few things] Signed-off-by: Nate Diller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/highmem.h | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) (limited to 'include/linux/highmem.h') diff --git a/include/linux/highmem.h b/include/linux/highmem.h index a515eb0afdf..b5f2ab42d98 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -94,17 +94,27 @@ static inline void clear_highpage(struct page *page) /* * Same but also flushes aliased cache contents to RAM. + * + * This must be a macro because KM_USER0 and friends aren't defined if + * !CONFIG_HIGHMEM */ -static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) +#define zero_user_page(page, offset, size, km_type) \ + do { \ + void *kaddr; \ + \ + BUG_ON((offset) + (size) > PAGE_SIZE); \ + \ + kaddr = kmap_atomic(page, km_type); \ + memset((char *)kaddr + (offset), 0, (size)); \ + flush_dcache_page(page); \ + kunmap_atomic(kaddr, (km_type)); \ + } while (0) + + +static inline void memclear_highpage_flush(struct page *page, + unsigned int offset, unsigned int size) { - void *kaddr; - - BUG_ON(offset + size > PAGE_SIZE); - - kaddr = kmap_atomic(page, KM_USER0); - memset((char *)kaddr + offset, 0, size); - flush_dcache_page(page); - kunmap_atomic(kaddr, KM_USER0); + zero_user_page(page, offset, size, KM_USER0); } #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE -- cgit v1.2.3