diff options
| author | Nate Diller <nate.diller@gmail.com> | 2007-05-09 02:35:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:55 -0700 |
| commit | 01f2705daf5a36208e69d7cf95db9c330f843af6 (patch) | |
| tree | 2d2c7a042c2466ed985f6e0950450c099f02725f /include/linux | |
| parent | 38a23e311b6cd389b9d8af2ea6c28c8cffbe581c (diff) | |
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 <nate.diller@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/highmem.h | 28 |
1 files changed, 19 insertions, 9 deletions
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 |