From 6850c4421481139dc2cf982358e79c833a50d73c Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Thu, 16 Dec 2010 00:32:38 +0100 Subject: [PATCH] drbd: get rid of unused debug code Long time ago, we had paranoia code in the bitmap that allocated one extra word, assigned a magic value, and checked on every occasion that the magic value was still unchanged. That debug code is unused, the extra long word complicates code a bit. Get rid of it. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_bitmap.c | 39 ++++++++------------------------ 1 file changed, 9 insertions(+), 30 deletions(-) diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c index 0e31e573af72..09d208b858e7 100644 --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -488,10 +488,7 @@ static int bm_clear_surplus(struct drbd_bitmap *b) * on disk and in core memory alike */ mask = cpu_to_lel(mask); - /* because of the "extra long to catch oob access" we allocate in - * drbd_bm_resize, bm_number_of_pages -1 is not necessarily the page - * containing the last _relevant_ bitmap word */ - p_addr = bm_map_pidx(b, bm_bit_to_page_idx(b, b->bm_bits - 1)); + p_addr = bm_map_pidx(b, b->bm_number_of_pages - 1); bm = p_addr + (tmp/BITS_PER_LONG); if (mask) { /* If mask != 0, we are not exactly aligned, so bm now points @@ -527,10 +524,7 @@ static void bm_set_surplus(struct drbd_bitmap *b) * on disk and in core memory alike */ mask = cpu_to_lel(mask); - /* because of the "extra long to catch oob access" we allocate in - * drbd_bm_resize, bm_number_of_pages -1 is not necessarily the page - * containing the last _relevant_ bitmap word */ - p_addr = bm_map_pidx(b, bm_bit_to_page_idx(b, b->bm_bits - 1)); + p_addr = bm_map_pidx(b, b->bm_number_of_pages - 1); bm = p_addr + (tmp/BITS_PER_LONG); if (mask) { /* If mask != 0, we are not exactly aligned, so bm now points @@ -556,15 +550,10 @@ static unsigned long bm_count_bits(struct drbd_bitmap *b) unsigned long *p_addr; unsigned long bits = 0; unsigned long mask = (1UL << (b->bm_bits & BITS_PER_LONG_MASK)) -1; - int idx, last_page, i, last_word; - - /* because of the "extra long to catch oob access" we allocate in - * drbd_bm_resize, bm_number_of_pages -1 is not necessarily the page - * containing the last _relevant_ bitmap word */ - last_page = bm_bit_to_page_idx(b, b->bm_bits-1); + int idx, i, last_word; /* all but last page */ - for (idx = 0; idx < last_page; idx++) { + for (idx = 0; idx < b->bm_number_of_pages - 1; idx++) { p_addr = __bm_map_pidx(b, idx, KM_USER0); for (i = 0; i < LWPP; i++) bits += hweight_long(p_addr[i]); @@ -627,7 +616,7 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len) int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits) { struct drbd_bitmap *b = mdev->bitmap; - unsigned long bits, words, owords, obits, *p_addr, *bm; + unsigned long bits, words, owords, obits; unsigned long want, have, onpages; /* number of pages */ struct page **npages, **opages = NULL; int err = 0, growing; @@ -681,8 +670,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits) } } - /* one extra long to catch off by one errors */ - want = ALIGN((words+1)*sizeof(long), PAGE_SIZE) >> PAGE_SHIFT; + want = ALIGN(words*sizeof(long), PAGE_SIZE) >> PAGE_SHIFT; have = b->bm_number_of_pages; if (want == have) { D_ASSERT(b->bm_pages != NULL); @@ -728,11 +716,6 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits) bm_free_pages(opages + want, have - want); } - p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, words)); - bm = p_addr + MLPP(words); - *bm = DRBD_MAGIC; - bm_unmap(p_addr); - (void)bm_clear_surplus(b); spin_unlock_irq(&b->bm_lock); @@ -845,7 +828,6 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, */ if (end == b->bm_words) b->bm_set -= bm_clear_surplus(b); - spin_unlock_irq(&b->bm_lock); } @@ -1030,7 +1012,7 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_id struct bm_aio_ctx ctx = { .flags = lazy_writeout_upper_idx ? BM_AIO_COPY_PAGES : 0 }; struct drbd_bitmap *b = mdev->bitmap; - int last_page, i, count = 0; + int num_pages, i, count = 0; unsigned long now; char ppb[10]; int err = 0; @@ -1046,10 +1028,7 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_id if (!ctx.flags) WARN_ON(!bm_is_locked(b)); - /* because of the "extra long to catch oob access" we allocate in - * drbd_bm_resize, bm_number_of_pages -1 is not necessarily the page - * containing the last _relevant_ bitmap word */ - last_page = bm_word_to_page_idx(b, b->bm_words - 1); + num_pages = b->bm_number_of_pages; now = jiffies; ctx.mdev = mdev; @@ -1058,7 +1037,7 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_id ctx.error = 0; /* let the layers below us try to merge these bios... */ - for (i = 0; i <= last_page; i++) { + for (i = 0; i < num_pages; i++) { /* ignore completely unchanged pages */ if (lazy_writeout_upper_idx && i == lazy_writeout_upper_idx) break; -- 2.39.2