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authorNate Diller <nate.diller@gmail.com>2007-05-09 02:35:07 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 12:30:55 -0700
commit01f2705daf5a36208e69d7cf95db9c330f843af6 (patch)
tree2d2c7a042c2466ed985f6e0950450c099f02725f /mm
parent38a23e311b6cd389b9d8af2ea6c28c8cffbe581c (diff)
downloadlinux-01f2705daf5a36208e69d7cf95db9c330f843af6.tar.gz
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 'mm')
-rw-r--r--mm/filemap_xip.c7
-rw-r--r--mm/truncate.c3
2 files changed, 3 insertions, 7 deletions
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index cbb335813ec..1b49dab9b25 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -434,7 +434,6 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
unsigned blocksize;
unsigned length;
struct page *page;
- void *kaddr;
BUG_ON(!mapping->a_ops->get_xip_page);
@@ -458,11 +457,7 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
else
return PTR_ERR(page);
}
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, 0, length);
- kunmap_atomic(kaddr, KM_USER0);
-
- flush_dcache_page(page);
+ zero_user_page(page, offset, length, KM_USER0);
return 0;
}
EXPORT_SYMBOL_GPL(xip_truncate_page);
diff --git a/mm/truncate.c b/mm/truncate.c
index 0f4b6d18ab0..4fbe1a2da5f 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -12,6 +12,7 @@
#include <linux/swap.h>
#include <linux/module.h>
#include <linux/pagemap.h>
+#include <linux/highmem.h>
#include <linux/pagevec.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/buffer_head.h> /* grr. try_to_release_page,
@@ -46,7 +47,7 @@ void do_invalidatepage(struct page *page, unsigned long offset)
static inline void truncate_partial_page(struct page *page, unsigned partial)
{
- memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial);
+ zero_user_page(page, partial, PAGE_CACHE_SIZE - partial, KM_USER0);
if (PagePrivate(page))
do_invalidatepage(page, partial);
}