We may now have to zero and flush higher order pages. Implement
clear_mapping_page and flush_mapping_page to do that job. Replace
the flushing and clearing at some key locations for the pagecache.
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>
---
fs/libfs.c | 4 ++--
include/linux/highmem.h | 31 +++++++++++++++++++++++++++++--
include/linux/pagemap.h | 1 +
mm/filemap.c | 8 ++++----
mm/filemap_xip.c | 4 ++--
5 files changed, 38 insertions(+), 10 deletions(-)
Index: linux-2.6.22-rc4-mm2/fs/libfs.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/fs/libfs.c 2007-06-19 20:10:05.000000000 -0700
+++ linux-2.6.22-rc4-mm2/fs/libfs.c 2007-06-19 20:10:45.000000000 -0700
@@ -330,8 +330,8 @@ int simple_rename(struct inode *old_dir,
int simple_readpage(struct file *file, struct page *page)
{
- clear_highpage(page);
- flush_dcache_page(page);
+ clear_mapping_page(page);
+ flush_mapping_page(page);
SetPageUptodate(page);
unlock_page(page);
return 0;
Index: linux-2.6.22-rc4-mm2/include/linux/highmem.h
===================================================================
--- linux-2.6.22-rc4-mm2.orig/include/linux/highmem.h 2007-06-19 20:06:06.000000000 -0700
+++ linux-2.6.22-rc4-mm2/include/linux/highmem.h 2007-06-19 20:30:06.000000000 -0700
@@ -124,14 +124,41 @@ static inline void clear_highpage(struct
kunmap_atomic(kaddr, KM_USER0);
}
+/*
+ * Clear a higher order page
+ */
+static inline void clear_mapping_page(struct page *page)
+{
+ int nr_pages = compound_pages(page);
+ int i;
+
+ for (i = 0; i < nr_pages; i++)
+ clear_highpage(page + i);
+}
+
+/*
+ * Primitive support for flushing higher order pages.
+ *
+ * A bit stupid: On many platforms flushing the first page
+ * will flush any TLB starting there
+ */
+static inline void flush_mapping_page(struct page *page)
+{
+ int nr_pages = compound_pages(page);
+ int i;
+
+ for (i = 0; i < nr_pages; i++)
+ flush_dcache_page(page + i);
+}
+
static inline void zero_user_segments(struct page *page,
unsigned start1, unsigned end1,
unsigned start2, unsigned end2)
{
void *kaddr = kmap_atomic(page, KM_USER0);
- BUG_ON(end1 > PAGE_SIZE ||
- end2 > PAGE_SIZE);
+ BUG_ON(end1 > compound_size(page) ||
+ end2 > compound_size(page));
if (end1 > start1)
memset(kaddr + start1, 0, end1 - start1);
Index: linux-2.6.22-rc4-mm2/mm/filemap.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/mm/filemap.c 2007-06-19 20:10:52.000000000 -0700
+++ linux-2.6.22-rc4-mm2/mm/filemap.c 2007-06-19 20:11:44.000000000 -0700
@@ -946,7 +946,7 @@ page_ok:
* before reading the page on the kernel side.
*/
if (mapping_writably_mapped(mapping))
- flush_dcache_page(page);
+ flush_mapping_page(page);
/*
* When a sequential read accesses a page several times,
@@ -2004,7 +2004,7 @@ int pagecache_write_end(struct file *fil
unsigned offset = page_cache_offset(mapping, pos);
struct inode *inode = mapping->host;
- flush_dcache_page(page);
+ flush_mapping_page(page);
ret = aops->commit_write(file, page, offset, offset+len);
unlock_page(page);
page_cache_release(page);
@@ -2216,7 +2216,7 @@ static ssize_t generic_perform_write_2co
kunmap_atomic(src, KM_USER0);
copied = bytes;
}
- flush_dcache_page(page);
+ flush_mapping_page(page);
status = a_ops->commit_write(file, page, offset, offset+bytes);
if (unlikely(status < 0 || status == AOP_TRUNCATED_PAGE))
@@ -2314,7 +2314,7 @@ again:
pagefault_disable();
copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
pagefault_enable();
- flush_dcache_page(page);
+ flush_mapping_page(page);
status = a_ops->write_end(file, mapping, pos, bytes, copied,
page, fsdata);
Index: linux-2.6.22-rc4-mm2/mm/filemap_xip.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/mm/filemap_xip.c 2007-06-19 20:12:10.000000000 -0700
+++ linux-2.6.22-rc4-mm2/mm/filemap_xip.c 2007-06-19 20:12:46.000000000 -0700
@@ -103,7 +103,7 @@ do_xip_mapping_read(struct address_space
* before reading the page on the kernel side.
*/
if (mapping_writably_mapped(mapping))
- flush_dcache_page(page);
+ flush_mapping_page(page);
/*
* Ok, we have the page, so now we can copy it to user space...
@@ -347,7 +347,7 @@ __xip_file_write(struct file *filp, cons
copied = bytes -
__copy_from_user_inatomic_nocache(kaddr, buf, bytes);
kunmap_atomic(kaddr, KM_USER0);
- flush_dcache_page(page);
+ flush_mapping_page(page);
if (likely(copied > 0)) {
status = copied;
--
-
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