[PATCH 003 of 8] md/bitmap: Cleaner separation of page attribute handlers in md/bitmap.

NeilBrown
2006-05-12T06:08:17Z

md/bitmap has some attributes per-page. Handling of these
attributes in largely abstracted in set_page_attr and
clear_page_attr. However get_page_attr exposes the
format used to store them. So prior to changing that
format, introduce test_page_attr instead of get_page_attr,
and make appropriate usage changes.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./drivers/md/bitmap.c | 41 ++++++++++++++++++++++-------------------
1 file changed, 22 insertions(+), 19 deletions(-)

diff ./drivers/md/bitmap.c~current~ ./drivers/md/bitmap.c
--- ./drivers/md/bitmap.c~current~ 2006-05-12 15:55:37.000000000 +1000
+++ ./drivers/md/bitmap.c 2006-05-12 15:56:51.000000000 +1000
@@ -717,9 +717,10 @@ static inline void clear_page_attr(struc
bitmap->filemap_attr[page->index] &= ~attr;
}

-static inline unsigned long get_page_attr(struct bitmap *bitmap, struct page *page)
+static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
+ enum bitmap_page_attr attr)
{
- return bitmap->filemap_attr[page->index];
+ return bitmap->filemap_attr[page->index] & attr;
}

/*
@@ -745,7 +746,7 @@ static void bitmap_file_set_bit(struct b

/* make sure the page stays cached until it gets written out */
- if (! (get_page_attr(bitmap, page) & BITMAP_PAGE_DIRTY))
+ if (! test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY))
get_page(page);

/* set the bit */
@@ -769,7 +770,8 @@ static void bitmap_writeback(struct bitm
* sync the dirty pages of the bitmap file to disk */
int bitmap_unplug(struct bitmap *bitmap)
{
- unsigned long i, attr, flags;
+ unsigned long i, flags;
+ int dirty, need_write;
struct page *page;
int wait = 0;
int err;
@@ -786,17 +788,18 @@ int bitmap_unplug(struct bitmap *bitmap)
return 0;
}
page = bitmap->filemap[i];
- attr = get_page_attr(bitmap, page);
+ dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
+ need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
- if ((attr & BITMAP_PAGE_DIRTY))
+ if (dirty)
wait = 1;
spin_unlock_irqrestore(&bitmap->lock, flags);

- if (attr & (BITMAP_PAGE_DIRTY | BITMAP_PAGE_NEEDWRITE)) {
+ if (dirty | need_write) {
err = write_page(bitmap, page, 0);
if (err == -EAGAIN) {
- if (attr & BITMAP_PAGE_DIRTY)
+ if (dirty)
err = write_page(bitmap, page, 1);
else
err = 0;
@@ -961,12 +964,11 @@ void bitmap_write_all(struct bitmap *bit
/* We don't actually write all bitmap blocks here,
* just flag them as needing to be written
*/
+ int i;

- unsigned long chunks = bitmap->chunks;
- unsigned long bytes = (chunks+7)/8 + sizeof(bitmap_super_t);
- unsigned long num_pages = (bytes + PAGE_SIZE-1) / PAGE_SIZE;
- while (num_pages--)
- bitmap->filemap_attr[num_pages] |= BITMAP_PAGE_NEEDWRITE;
+ for (i=0; i < bitmap->file_pages; i++)
+ set_page_attr(bitmap, bitmap->filemap[i],
+ BITMAP_PAGE_NEEDWRITE);
}

@@ -997,7 +999,6 @@ int bitmap_daemon_work(struct bitmap *bi
struct page *page = NULL, *lastpage = NULL;
int err = 0;
int blocks;
- int attr;
void *paddr;

if (bitmap == NULL)
@@ -1019,13 +1020,15 @@ int bitmap_daemon_work(struct bitmap *bi

if (page != lastpage) {
/* skip this page unless it's marked as needing cleaning */
- if (!((attr=get_page_attr(bitmap, page)) & BITMAP_PAGE_CLEAN)) {
- if (attr & BITMAP_PAGE_NEEDWRITE) {
+ if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
+ int need_write = test_page_attr(bitmap, page,
+ BITMAP_PAGE_NEEDWRITE);
+ if (need_write) {
get_page(page);
clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
}
spin_unlock_irqrestore(&bitmap->lock, flags);
- if (attr & BITMAP_PAGE_NEEDWRITE) {
+ if (need_write) {
switch (write_page(bitmap, page, 0)) {
case -EAGAIN:
set_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
@@ -1043,7 +1046,7 @@ int bitmap_daemon_work(struct bitmap *bi
/* grab the new page, sync and release the old */
get_page(page);
if (lastpage != NULL) {
- if (get_page_attr(bitmap, lastpage) & BITMAP_PAGE_NEEDWRITE) {
+ if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
err = write_page(bitmap, lastpage, 0);
@@ -1097,7 +1100,7 @@ int bitmap_daemon_work(struct bitmap *bi
/* now sync the final page */
if (lastpage != NULL) {
spin_lock_irqsave(&bitmap->lock, flags);
- if (get_page_attr(bitmap, lastpage) &BITMAP_PAGE_NEEDWRITE) {
+ if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
err = write_page(bitmap, lastpage, 0);