diff options
| -rw-r--r-- | drivers/block/drbd/drbd_bitmap.c | 49 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_int.h | 13 |
2 files changed, 52 insertions, 10 deletions
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c index 4be737055718..bc89c4a30cbc 100644 --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -188,6 +188,9 @@ void drbd_bm_unlock(struct drbd_conf *mdev) /* to mark for lazy writeout once syncer cleared all clearable bits, * we if bits have been cleared since last IO. */ #define BM_PAGE_LAZY_WRITEOUT 28 +/* pages marked with this "HINT" will be considered for writeout + * on activity log transactions */ +#define BM_PAGE_HINT_WRITEOUT 27 /* store_page_idx uses non-atomic assignment. It is only used directly after * allocating the page. All other bm_set_page_* and bm_clear_page_* need to @@ -237,6 +240,27 @@ static void bm_set_page_need_writeout(struct page *page) set_bit(BM_PAGE_NEED_WRITEOUT, &page_private(page)); } +/** + * drbd_bm_mark_for_writeout() - mark a page with a "hint" to be considered for writeout + * @mdev: DRBD device. + * @page_nr: the bitmap page to mark with the "hint" flag + * + * From within an activity log transaction, we mark a few pages with these + * hints, then call drbd_bm_write_hinted(), which will only write out changed + * pages which are flagged with this mark. + */ +void drbd_bm_mark_for_writeout(struct drbd_conf *mdev, int page_nr) +{ + struct page *page; + if (page_nr >= mdev->bitmap->bm_number_of_pages) { + dev_warn(DEV, "BAD: page_nr: %u, number_of_pages: %u\n", + page_nr, (int)mdev->bitmap->bm_number_of_pages); + return; + } + page = mdev->bitmap->bm_pages[page_nr]; + set_bit(BM_PAGE_HINT_WRITEOUT, &page_private(page)); +} + static int bm_test_page_unchanged(struct page *page) { volatile const unsigned long *addr = &page_private(page); @@ -897,6 +921,7 @@ struct bm_aio_ctx { struct completion done; unsigned flags; #define BM_AIO_COPY_PAGES 1 +#define BM_AIO_WRITE_HINTED 2 int error; }; @@ -1007,13 +1032,13 @@ static void bm_page_io_async(struct bm_aio_ctx *ctx, int page_nr, int rw) __must /* * bm_rw: read/write the whole bitmap from/to its on disk location. */ -static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_idx) __must_hold(local) +static int bm_rw(struct drbd_conf *mdev, int rw, unsigned flags, unsigned lazy_writeout_upper_idx) __must_hold(local) { struct bm_aio_ctx ctx = { .mdev = mdev, .in_flight = ATOMIC_INIT(1), .done = COMPLETION_INITIALIZER_ONSTACK(ctx.done), - .flags = lazy_writeout_upper_idx ? BM_AIO_COPY_PAGES : 0, + .flags = flags, }; struct drbd_bitmap *b = mdev->bitmap; int num_pages, i, count = 0; @@ -1042,6 +1067,10 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_id if (lazy_writeout_upper_idx && i == lazy_writeout_upper_idx) break; if (rw & WRITE) { + if ((flags & BM_AIO_WRITE_HINTED) && + !test_and_clear_bit(BM_PAGE_HINT_WRITEOUT, + &page_private(b->bm_pages[i]))) + continue; if (bm_test_page_unchanged(b->bm_pages[i])) { dynamic_dev_dbg(DEV, "skipped bm write for idx %u\n", i); continue; @@ -1099,7 +1128,7 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_id */ int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local) { - return bm_rw(mdev, READ, 0); + return bm_rw(mdev, READ, 0, 0); } /** @@ -1110,7 +1139,7 @@ int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local) */ int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local) { - return bm_rw(mdev, WRITE, 0); + return bm_rw(mdev, WRITE, 0, 0); } /** @@ -1120,12 +1149,20 @@ int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local) */ int drbd_bm_write_lazy(struct drbd_conf *mdev, unsigned upper_idx) __must_hold(local) { - return bm_rw(mdev, WRITE, upper_idx); + return bm_rw(mdev, WRITE, BM_AIO_COPY_PAGES, upper_idx); } +/** + * drbd_bm_write_hinted() - Write bitmap pages with "hint" marks, if they have changed. + * @mdev: DRBD device. + */ +int drbd_bm_write_hinted(struct drbd_conf *mdev) __must_hold(local) +{ + return bm_rw(mdev, WRITE, BM_AIO_WRITE_HINTED | BM_AIO_COPY_PAGES, 0); +} /** - * drbd_bm_write_page: Writes a PAGE_SIZE aligned piece of bitmap + * drbd_bm_write_page() - Writes a PAGE_SIZE aligned piece of bitmap * @mdev: DRBD device. * @idx: bitmap page index * diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 93eb3a7ac711..edfdeb62c18f 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -1310,11 +1310,14 @@ struct bm_extent { #define SLEEP_TIME (HZ/10) -#define BM_BLOCK_SHIFT 12 /* 4k per bit */ +/* We do bitmap IO in units of 4k blocks. + * We also still have a hardcoded 4k per bit relation. */ +#define BM_BLOCK_SHIFT 12 /* 4k per bit */ #define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT) -/* (9+3) : 512 bytes @ 8 bits; representing 16M storage - * per sector of on disk bitmap */ -#define BM_EXT_SHIFT (BM_BLOCK_SHIFT + MD_SECTOR_SHIFT + 3) /* = 24 */ +/* mostly arbitrarily set the represented size of one bitmap extent, + * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap + * at 4k per bit resolution) */ +#define BM_EXT_SHIFT 24 /* 16 MiB per resync extent */ #define BM_EXT_SIZE (1<<BM_EXT_SHIFT) #if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12) @@ -1408,7 +1411,9 @@ extern int drbd_bm_test_bit(struct drbd_conf *mdev, unsigned long bitnr); extern int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr); extern int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(local); extern int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local); +extern void drbd_bm_mark_for_writeout(struct drbd_conf *mdev, int page_nr); extern int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local); +extern int drbd_bm_write_hinted(struct drbd_conf *mdev) __must_hold(local); extern unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, unsigned long al_enr); extern size_t drbd_bm_words(struct drbd_conf *mdev); |