The attached patch makes the page-becoming-writable notification a VMA
operation only - it removes the equivalent address-space operation and the
chaining of the call.
Furthermore, it fixes the kAFS filesystem to take account of this.
Signed-Off-By: David Howells <[email protected]>
---
warthog>diffstat -p1 cachefs-2612rc1mm3.diff
fs/afs/file.c | 30 ++++++++++++++++++++++++++----
include/linux/fs.h | 3 ---
mm/filemap.c | 19 +------------------
3 files changed, 27 insertions(+), 25 deletions(-)
diff -uNr linux-2.6.12-rc1-mm3/fs/afs/file.c linux-2.6.12-rc1-mm3-cachefs/fs/afs/file.c
--- linux-2.6.12-rc1-mm3/fs/afs/file.c 2005-03-29 15:42:00.000000000 +0100
+++ linux-2.6.12-rc1-mm3-cachefs/fs/afs/file.c 2005-03-29 18:31:43.000000000 +0100
@@ -33,8 +33,10 @@
static ssize_t afs_file_write(struct file *file, const char __user *buf,
size_t size, loff_t *off);
+static int afs_file_mmap(struct file * file, struct vm_area_struct * vma);
+
#ifdef CONFIG_AFS_FSCACHE
-static int afs_file_page_mkwrite(struct page *page);
+static int afs_file_page_mkwrite(struct vm_area_struct *vma, struct page *page);
#endif
struct inode_operations afs_file_inode_operations = {
@@ -44,7 +46,7 @@
struct file_operations afs_file_file_operations = {
.read = generic_file_read,
.write = afs_file_write,
- .mmap = generic_file_mmap,
+ .mmap = afs_file_mmap,
#if 0
.open = afs_file_open,
.release = afs_file_release,
@@ -58,6 +60,11 @@
.set_page_dirty = __set_page_dirty_nobuffers,
.releasepage = afs_file_releasepage,
.invalidatepage = afs_file_invalidatepage,
+};
+
+struct vm_operations_struct afs_fs_vm_operations = {
+ .nopage = filemap_nopage,
+ .populate = filemap_populate,
#ifdef CONFIG_AFS_FSCACHE
.page_mkwrite = afs_file_page_mkwrite,
#endif
@@ -81,6 +88,20 @@
/*****************************************************************************/
/*
+ * set up a memory mapping on an AFS file
+ * - we set our own VMA ops so that we can catch the page becoming writable for
+ * userspace for shared-writable mmap
+ */
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ file_accessed(file);
+ vma->vm_ops = &afs_fs_vm_operations;
+ return 0;
+
+} /* end afs_file_mmap() */
+
+/*****************************************************************************/
+/*
* deal with notification that a page was read from the cache
*/
#ifdef CONFIG_AFS_FSCACHE
@@ -318,10 +339,11 @@
/*****************************************************************************/
/*
- * wait for the disc cache to finish writing before permitting
+ * wait for the disc cache to finish writing before permitting modification of
+ * our page in the page cache
*/
#ifdef CONFIG_AFS_FSCACHE
-static int afs_file_page_mkwrite(struct page *page)
+static int afs_file_page_mkwrite(struct vm_area_struct *vma, struct page *page)
{
wait_on_page_fs_misc(page);
return 0;
diff -uNr linux-2.6.12-rc1-mm3/include/linux/fs.h linux-2.6.12-rc1-mm3-cachefs/include/linux/fs.h
--- linux-2.6.12-rc1-mm3/include/linux/fs.h 2005-03-29 15:42:08.000000000 +0100
+++ linux-2.6.12-rc1-mm3-cachefs/include/linux/fs.h 2005-03-29 18:16:39.000000000 +0100
@@ -332,9 +332,6 @@
int (*releasepage) (struct page *, int);
ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
loff_t offset, unsigned long nr_segs);
-
- /* notification that a page is about to become writable */
- int (*page_mkwrite)(struct page *page);
};
struct backing_dev_info;
diff -uNr linux-2.6.12-rc1-mm3/mm/filemap.c linux-2.6.12-rc1-mm3-cachefs/mm/filemap.c
--- linux-2.6.12-rc1-mm3/mm/filemap.c 2005-03-29 15:42:11.000000000 +0100
+++ linux-2.6.12-rc1-mm3-cachefs/mm/filemap.c 2005-03-29 18:24:22.000000000 +0100
@@ -1535,25 +1535,11 @@
return 0;
}
-/*
- * pass notification that a page is becoming writable up to the filesystem
- */
-static int filemap_page_mkwrite(struct vm_area_struct *vma, struct page *page)
-{
- return page->mapping->a_ops->page_mkwrite(page);
-}
-
struct vm_operations_struct generic_file_vm_ops = {
.nopage = filemap_nopage,
.populate = filemap_populate,
};
-struct vm_operations_struct generic_file_vm_mkwr_ops = {
- .nopage = filemap_nopage,
- .populate = filemap_populate,
- .page_mkwrite = filemap_page_mkwrite,
-};
-
/* This is used for a general mmap of a disk file */
int generic_file_mmap(struct file * file, struct vm_area_struct * vma)
@@ -1563,10 +1549,7 @@
if (!mapping->a_ops->readpage)
return -ENOEXEC;
file_accessed(file);
- if (!mapping->a_ops->page_mkwrite)
- vma->vm_ops = &generic_file_vm_ops;
- else
- vma->vm_ops = &generic_file_vm_mkwr_ops;
+ vma->vm_ops = &generic_file_vm_ops;
return 0;
}
EXPORT_SYMBOL(filemap_populate);
-
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