> On Mar 3, 2025, at 11:08, Heming Zhao <heming.zhao@xxxxxxxx> wrote:
>
> Hi Glass,
>
> The code looks good to me.
> The commit log needs to be revised.
>
> On 3/2/25 12:39, Su Yue wrote:
>> In clustermd, Separate write-intent-bitmaps are used for each cluster
>> node:
>
> Change 'Separate' to lowercase 'separate'.
>> 0 4k 8k 12k
>> -------------------------------------------------------------------
>> | idle | md super | bm super [0] + bits |
>> | bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] |
>> | bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits |
>> | bm bits [3, contd] | | |
>> So in node 1, pg_index in __write_sb_page() could equal to
>> bitmap->storage.file_pages. Then bitmap_limit will be calculated to
>> 0. md_super_write() will be called with 0 size.
>> That means node the first 4k sb area of node 1 will never be updated
>> through filemap_write_page().
>
> "That means node the ...", should remove the word 'node'?
Thanks. Fixed in v3.
—
Su
>
> - Heming
>
>> This bug causes hang of mdadm/clustermd_tests/01r1_Grow_resize.
>> Here use (pg_index % bitmap->storage.file_pages) to calculation of
>> bitmap_limit correct.
>> Fixes: ab99a87542f1 ("md/md-bitmap: fix writing non bitmap pages")
>> Signed-off-by: Su Yue <glass.su@xxxxxxxx>
>> ---
>> drivers/md/md-bitmap.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>> diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
>> index 23c09d22fcdb..9ae6cc8e30cb 100644
>> --- a/drivers/md/md-bitmap.c
>> +++ b/drivers/md/md-bitmap.c
>> @@ -426,8 +426,8 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
>> struct block_device *bdev;
>> struct mddev *mddev = bitmap->mddev;
>> struct bitmap_storage *store = &bitmap->storage;
>> - unsigned int bitmap_limit = (bitmap->storage.file_pages - pg_index) <<
>> - PAGE_SHIFT;
>> + unsigned long num_pages = bitmap->storage.file_pages;
>> + unsigned int bitmap_limit = (num_pages - pg_index % num_pages) << PAGE_SHIFT;
>> loff_t sboff, offset = mddev->bitmap_info.offset;
>> sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE;
>> unsigned int size = PAGE_SIZE;
>> @@ -436,7 +436,7 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
>> bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
>> /* we compare length (page numbers), not page offset. */
>> - if ((pg_index - store->sb_index) == store->file_pages - 1) {
>> + if ((pg_index - store->sb_index) == num_pages - 1) {
>> unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
>> if (last_page_size == 0)
>
