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![Philipp Reisner](/assets/img/avatar_default.png)
The "surplus" bits of the old (smaller) bitmap must be clean in case of online-grow without resync. Note: Reverted 67ae8b80d4a116ab3b7094eb3723506b20c06dff as well, since the lines added by this patch are redundant. The bits get set by the bm_set_surplus(b) call before that. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
1335 lines
35 KiB
C
1335 lines
35 KiB
C
/*
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drbd_bitmap.c
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This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
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Copyright (C) 2004-2008, LINBIT Information Technologies GmbH.
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Copyright (C) 2004-2008, Philipp Reisner <philipp.reisner@linbit.com>.
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Copyright (C) 2004-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
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drbd is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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drbd is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with drbd; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/bitops.h>
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#include <linux/vmalloc.h>
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#include <linux/string.h>
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#include <linux/drbd.h>
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#include <linux/slab.h>
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#include <asm/kmap_types.h>
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#include "drbd_int.h"
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/* OPAQUE outside this file!
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* interface defined in drbd_int.h
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* convention:
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* function name drbd_bm_... => used elsewhere, "public".
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* function name bm_... => internal to implementation, "private".
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* Note that since find_first_bit returns int, at the current granularity of
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* the bitmap (4KB per byte), this implementation "only" supports up to
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* 1<<(32+12) == 16 TB...
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*/
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/*
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* NOTE
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* Access to the *bm_pages is protected by bm_lock.
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* It is safe to read the other members within the lock.
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*
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* drbd_bm_set_bits is called from bio_endio callbacks,
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* We may be called with irq already disabled,
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* so we need spin_lock_irqsave().
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* And we need the kmap_atomic.
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*/
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struct drbd_bitmap {
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struct page **bm_pages;
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spinlock_t bm_lock;
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/* WARNING unsigned long bm_*:
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* 32bit number of bit offset is just enough for 512 MB bitmap.
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* it will blow up if we make the bitmap bigger...
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* not that it makes much sense to have a bitmap that large,
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* rather change the granularity to 16k or 64k or something.
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* (that implies other problems, however...)
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*/
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unsigned long bm_set; /* nr of set bits; THINK maybe atomic_t? */
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unsigned long bm_bits;
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size_t bm_words;
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size_t bm_number_of_pages;
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sector_t bm_dev_capacity;
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struct mutex bm_change; /* serializes resize operations */
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atomic_t bm_async_io;
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wait_queue_head_t bm_io_wait;
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unsigned long bm_flags;
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/* debugging aid, in case we are still racy somewhere */
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char *bm_why;
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struct task_struct *bm_task;
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};
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/* definition of bits in bm_flags */
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#define BM_LOCKED 0
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#define BM_MD_IO_ERROR 1
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#define BM_P_VMALLOCED 2
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static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
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unsigned long e, int val, const enum km_type km);
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static int bm_is_locked(struct drbd_bitmap *b)
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{
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return test_bit(BM_LOCKED, &b->bm_flags);
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}
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#define bm_print_lock_info(m) __bm_print_lock_info(m, __func__)
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static void __bm_print_lock_info(struct drbd_conf *mdev, const char *func)
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{
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struct drbd_bitmap *b = mdev->bitmap;
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if (!__ratelimit(&drbd_ratelimit_state))
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return;
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dev_err(DEV, "FIXME %s in %s, bitmap locked for '%s' by %s\n",
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current == mdev->receiver.task ? "receiver" :
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current == mdev->asender.task ? "asender" :
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current == mdev->worker.task ? "worker" : current->comm,
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func, b->bm_why ?: "?",
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b->bm_task == mdev->receiver.task ? "receiver" :
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b->bm_task == mdev->asender.task ? "asender" :
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b->bm_task == mdev->worker.task ? "worker" : "?");
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}
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void drbd_bm_lock(struct drbd_conf *mdev, char *why)
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{
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struct drbd_bitmap *b = mdev->bitmap;
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int trylock_failed;
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if (!b) {
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dev_err(DEV, "FIXME no bitmap in drbd_bm_lock!?\n");
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return;
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}
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trylock_failed = !mutex_trylock(&b->bm_change);
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if (trylock_failed) {
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dev_warn(DEV, "%s going to '%s' but bitmap already locked for '%s' by %s\n",
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current == mdev->receiver.task ? "receiver" :
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current == mdev->asender.task ? "asender" :
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current == mdev->worker.task ? "worker" : current->comm,
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why, b->bm_why ?: "?",
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b->bm_task == mdev->receiver.task ? "receiver" :
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b->bm_task == mdev->asender.task ? "asender" :
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b->bm_task == mdev->worker.task ? "worker" : "?");
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mutex_lock(&b->bm_change);
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}
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if (__test_and_set_bit(BM_LOCKED, &b->bm_flags))
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dev_err(DEV, "FIXME bitmap already locked in bm_lock\n");
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b->bm_why = why;
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b->bm_task = current;
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}
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void drbd_bm_unlock(struct drbd_conf *mdev)
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{
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struct drbd_bitmap *b = mdev->bitmap;
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if (!b) {
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dev_err(DEV, "FIXME no bitmap in drbd_bm_unlock!?\n");
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return;
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}
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if (!__test_and_clear_bit(BM_LOCKED, &mdev->bitmap->bm_flags))
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dev_err(DEV, "FIXME bitmap not locked in bm_unlock\n");
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b->bm_why = NULL;
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b->bm_task = NULL;
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mutex_unlock(&b->bm_change);
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}
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/* word offset to long pointer */
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static unsigned long *__bm_map_paddr(struct drbd_bitmap *b, unsigned long offset, const enum km_type km)
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{
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struct page *page;
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unsigned long page_nr;
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/* page_nr = (word*sizeof(long)) >> PAGE_SHIFT; */
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page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3);
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BUG_ON(page_nr >= b->bm_number_of_pages);
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page = b->bm_pages[page_nr];
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return (unsigned long *) kmap_atomic(page, km);
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}
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static unsigned long * bm_map_paddr(struct drbd_bitmap *b, unsigned long offset)
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{
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return __bm_map_paddr(b, offset, KM_IRQ1);
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}
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static void __bm_unmap(unsigned long *p_addr, const enum km_type km)
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{
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kunmap_atomic(p_addr, km);
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};
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static void bm_unmap(unsigned long *p_addr)
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{
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return __bm_unmap(p_addr, KM_IRQ1);
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}
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/* long word offset of _bitmap_ sector */
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#define S2W(s) ((s)<<(BM_EXT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL))
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/* word offset from start of bitmap to word number _in_page_
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* modulo longs per page
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#define MLPP(X) ((X) % (PAGE_SIZE/sizeof(long))
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hm, well, Philipp thinks gcc might not optimze the % into & (... - 1)
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so do it explicitly:
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*/
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#define MLPP(X) ((X) & ((PAGE_SIZE/sizeof(long))-1))
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/* Long words per page */
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#define LWPP (PAGE_SIZE/sizeof(long))
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/*
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* actually most functions herein should take a struct drbd_bitmap*, not a
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* struct drbd_conf*, but for the debug macros I like to have the mdev around
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* to be able to report device specific.
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*/
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static void bm_free_pages(struct page **pages, unsigned long number)
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{
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unsigned long i;
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if (!pages)
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return;
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for (i = 0; i < number; i++) {
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if (!pages[i]) {
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printk(KERN_ALERT "drbd: bm_free_pages tried to free "
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"a NULL pointer; i=%lu n=%lu\n",
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i, number);
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continue;
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}
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__free_page(pages[i]);
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pages[i] = NULL;
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}
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}
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static void bm_vk_free(void *ptr, int v)
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{
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if (v)
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vfree(ptr);
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else
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kfree(ptr);
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}
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/*
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* "have" and "want" are NUMBER OF PAGES.
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*/
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static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want)
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{
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struct page **old_pages = b->bm_pages;
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struct page **new_pages, *page;
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unsigned int i, bytes, vmalloced = 0;
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unsigned long have = b->bm_number_of_pages;
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BUG_ON(have == 0 && old_pages != NULL);
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BUG_ON(have != 0 && old_pages == NULL);
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if (have == want)
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return old_pages;
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/* Trying kmalloc first, falling back to vmalloc.
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* GFP_KERNEL is ok, as this is done when a lower level disk is
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* "attached" to the drbd. Context is receiver thread or cqueue
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* thread. As we have no disk yet, we are not in the IO path,
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* not even the IO path of the peer. */
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bytes = sizeof(struct page *)*want;
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new_pages = kmalloc(bytes, GFP_KERNEL);
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if (!new_pages) {
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new_pages = vmalloc(bytes);
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if (!new_pages)
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return NULL;
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vmalloced = 1;
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}
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memset(new_pages, 0, bytes);
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if (want >= have) {
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for (i = 0; i < have; i++)
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new_pages[i] = old_pages[i];
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for (; i < want; i++) {
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page = alloc_page(GFP_HIGHUSER);
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if (!page) {
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bm_free_pages(new_pages + have, i - have);
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bm_vk_free(new_pages, vmalloced);
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return NULL;
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}
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new_pages[i] = page;
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}
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} else {
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for (i = 0; i < want; i++)
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new_pages[i] = old_pages[i];
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/* NOT HERE, we are outside the spinlock!
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bm_free_pages(old_pages + want, have - want);
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*/
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}
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if (vmalloced)
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set_bit(BM_P_VMALLOCED, &b->bm_flags);
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else
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clear_bit(BM_P_VMALLOCED, &b->bm_flags);
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return new_pages;
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}
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/*
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* called on driver init only. TODO call when a device is created.
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* allocates the drbd_bitmap, and stores it in mdev->bitmap.
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*/
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int drbd_bm_init(struct drbd_conf *mdev)
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{
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struct drbd_bitmap *b = mdev->bitmap;
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WARN_ON(b != NULL);
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b = kzalloc(sizeof(struct drbd_bitmap), GFP_KERNEL);
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if (!b)
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return -ENOMEM;
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spin_lock_init(&b->bm_lock);
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mutex_init(&b->bm_change);
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init_waitqueue_head(&b->bm_io_wait);
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mdev->bitmap = b;
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return 0;
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}
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sector_t drbd_bm_capacity(struct drbd_conf *mdev)
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{
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ERR_IF(!mdev->bitmap) return 0;
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return mdev->bitmap->bm_dev_capacity;
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}
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/* called on driver unload. TODO: call when a device is destroyed.
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*/
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void drbd_bm_cleanup(struct drbd_conf *mdev)
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{
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ERR_IF (!mdev->bitmap) return;
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bm_free_pages(mdev->bitmap->bm_pages, mdev->bitmap->bm_number_of_pages);
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bm_vk_free(mdev->bitmap->bm_pages, test_bit(BM_P_VMALLOCED, &mdev->bitmap->bm_flags));
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kfree(mdev->bitmap);
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mdev->bitmap = NULL;
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}
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/*
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* since (b->bm_bits % BITS_PER_LONG) != 0,
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* this masks out the remaining bits.
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* Returns the number of bits cleared.
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*/
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static int bm_clear_surplus(struct drbd_bitmap *b)
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{
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const unsigned long mask = (1UL << (b->bm_bits & (BITS_PER_LONG-1))) - 1;
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size_t w = b->bm_bits >> LN2_BPL;
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int cleared = 0;
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unsigned long *p_addr, *bm;
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p_addr = bm_map_paddr(b, w);
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bm = p_addr + MLPP(w);
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if (w < b->bm_words) {
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cleared = hweight_long(*bm & ~mask);
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*bm &= mask;
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w++; bm++;
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}
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if (w < b->bm_words) {
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cleared += hweight_long(*bm);
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*bm = 0;
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}
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bm_unmap(p_addr);
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return cleared;
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}
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static void bm_set_surplus(struct drbd_bitmap *b)
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{
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const unsigned long mask = (1UL << (b->bm_bits & (BITS_PER_LONG-1))) - 1;
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size_t w = b->bm_bits >> LN2_BPL;
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unsigned long *p_addr, *bm;
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p_addr = bm_map_paddr(b, w);
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bm = p_addr + MLPP(w);
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if (w < b->bm_words) {
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*bm |= ~mask;
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bm++; w++;
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}
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if (w < b->bm_words) {
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*bm = ~(0UL);
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}
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bm_unmap(p_addr);
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}
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static unsigned long __bm_count_bits(struct drbd_bitmap *b, const int swap_endian)
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{
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unsigned long *p_addr, *bm, offset = 0;
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unsigned long bits = 0;
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unsigned long i, do_now;
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while (offset < b->bm_words) {
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i = do_now = min_t(size_t, b->bm_words-offset, LWPP);
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p_addr = __bm_map_paddr(b, offset, KM_USER0);
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bm = p_addr + MLPP(offset);
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while (i--) {
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#ifndef __LITTLE_ENDIAN
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if (swap_endian)
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*bm = lel_to_cpu(*bm);
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#endif
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bits += hweight_long(*bm++);
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}
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__bm_unmap(p_addr, KM_USER0);
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offset += do_now;
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cond_resched();
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}
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return bits;
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}
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static unsigned long bm_count_bits(struct drbd_bitmap *b)
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{
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return __bm_count_bits(b, 0);
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}
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static unsigned long bm_count_bits_swap_endian(struct drbd_bitmap *b)
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{
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return __bm_count_bits(b, 1);
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}
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/* offset and len in long words.*/
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static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
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{
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unsigned long *p_addr, *bm;
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size_t do_now, end;
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#define BM_SECTORS_PER_BIT (BM_BLOCK_SIZE/512)
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end = offset + len;
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if (end > b->bm_words) {
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printk(KERN_ALERT "drbd: bm_memset end > bm_words\n");
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return;
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}
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while (offset < end) {
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do_now = min_t(size_t, ALIGN(offset + 1, LWPP), end) - offset;
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p_addr = bm_map_paddr(b, offset);
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bm = p_addr + MLPP(offset);
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if (bm+do_now > p_addr + LWPP) {
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printk(KERN_ALERT "drbd: BUG BUG BUG! p_addr:%p bm:%p do_now:%d\n",
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p_addr, bm, (int)do_now);
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break; /* breaks to after catch_oob_access_end() only! */
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}
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memset(bm, c, do_now * sizeof(long));
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bm_unmap(p_addr);
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offset += do_now;
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}
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}
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|
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/*
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* make sure the bitmap has enough room for the attached storage,
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* if necessary, resize.
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* called whenever we may have changed the device size.
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* returns -ENOMEM if we could not allocate enough memory, 0 on success.
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* In case this is actually a resize, we copy the old bitmap into the new one.
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* Otherwise, the bitmap is initialized to all bits set.
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*/
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int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits)
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{
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struct drbd_bitmap *b = mdev->bitmap;
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unsigned long bits, words, owords, obits, *p_addr, *bm;
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unsigned long want, have, onpages; /* number of pages */
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struct page **npages, **opages = NULL;
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int err = 0, growing;
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int opages_vmalloced;
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ERR_IF(!b) return -ENOMEM;
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drbd_bm_lock(mdev, "resize");
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dev_info(DEV, "drbd_bm_resize called with capacity == %llu\n",
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(unsigned long long)capacity);
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if (capacity == b->bm_dev_capacity)
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goto out;
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opages_vmalloced = test_bit(BM_P_VMALLOCED, &b->bm_flags);
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if (capacity == 0) {
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spin_lock_irq(&b->bm_lock);
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opages = b->bm_pages;
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onpages = b->bm_number_of_pages;
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owords = b->bm_words;
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b->bm_pages = NULL;
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b->bm_number_of_pages =
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b->bm_set =
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b->bm_bits =
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b->bm_words =
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b->bm_dev_capacity = 0;
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spin_unlock_irq(&b->bm_lock);
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bm_free_pages(opages, onpages);
|
|
bm_vk_free(opages, opages_vmalloced);
|
|
goto out;
|
|
}
|
|
bits = BM_SECT_TO_BIT(ALIGN(capacity, BM_SECT_PER_BIT));
|
|
|
|
/* if we would use
|
|
words = ALIGN(bits,BITS_PER_LONG) >> LN2_BPL;
|
|
a 32bit host could present the wrong number of words
|
|
to a 64bit host.
|
|
*/
|
|
words = ALIGN(bits, 64) >> LN2_BPL;
|
|
|
|
if (get_ldev(mdev)) {
|
|
D_ASSERT((u64)bits <= (((u64)mdev->ldev->md.md_size_sect-MD_BM_OFFSET) << 12));
|
|
put_ldev(mdev);
|
|
}
|
|
|
|
/* one extra long to catch off by one errors */
|
|
want = ALIGN((words+1)*sizeof(long), PAGE_SIZE) >> PAGE_SHIFT;
|
|
have = b->bm_number_of_pages;
|
|
if (want == have) {
|
|
D_ASSERT(b->bm_pages != NULL);
|
|
npages = b->bm_pages;
|
|
} else {
|
|
if (FAULT_ACTIVE(mdev, DRBD_FAULT_BM_ALLOC))
|
|
npages = NULL;
|
|
else
|
|
npages = bm_realloc_pages(b, want);
|
|
}
|
|
|
|
if (!npages) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
opages = b->bm_pages;
|
|
owords = b->bm_words;
|
|
obits = b->bm_bits;
|
|
|
|
growing = bits > obits;
|
|
if (opages && growing && set_new_bits)
|
|
bm_set_surplus(b);
|
|
|
|
b->bm_pages = npages;
|
|
b->bm_number_of_pages = want;
|
|
b->bm_bits = bits;
|
|
b->bm_words = words;
|
|
b->bm_dev_capacity = capacity;
|
|
|
|
if (growing) {
|
|
if (set_new_bits) {
|
|
bm_memset(b, owords, 0xff, words-owords);
|
|
b->bm_set += bits - obits;
|
|
} else
|
|
bm_memset(b, owords, 0x00, words-owords);
|
|
|
|
}
|
|
|
|
if (want < have) {
|
|
/* implicit: (opages != NULL) && (opages != npages) */
|
|
bm_free_pages(opages + want, have - want);
|
|
}
|
|
|
|
p_addr = bm_map_paddr(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);
|
|
if (opages != npages)
|
|
bm_vk_free(opages, opages_vmalloced);
|
|
if (!growing)
|
|
b->bm_set = bm_count_bits(b);
|
|
dev_info(DEV, "resync bitmap: bits=%lu words=%lu\n", bits, words);
|
|
|
|
out:
|
|
drbd_bm_unlock(mdev);
|
|
return err;
|
|
}
|
|
|
|
/* inherently racy:
|
|
* if not protected by other means, return value may be out of date when
|
|
* leaving this function...
|
|
* we still need to lock it, since it is important that this returns
|
|
* bm_set == 0 precisely.
|
|
*
|
|
* maybe bm_set should be atomic_t ?
|
|
*/
|
|
static unsigned long _drbd_bm_total_weight(struct drbd_conf *mdev)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long s;
|
|
unsigned long flags;
|
|
|
|
ERR_IF(!b) return 0;
|
|
ERR_IF(!b->bm_pages) return 0;
|
|
|
|
spin_lock_irqsave(&b->bm_lock, flags);
|
|
s = b->bm_set;
|
|
spin_unlock_irqrestore(&b->bm_lock, flags);
|
|
|
|
return s;
|
|
}
|
|
|
|
unsigned long drbd_bm_total_weight(struct drbd_conf *mdev)
|
|
{
|
|
unsigned long s;
|
|
/* if I don't have a disk, I don't know about out-of-sync status */
|
|
if (!get_ldev_if_state(mdev, D_NEGOTIATING))
|
|
return 0;
|
|
s = _drbd_bm_total_weight(mdev);
|
|
put_ldev(mdev);
|
|
return s;
|
|
}
|
|
|
|
size_t drbd_bm_words(struct drbd_conf *mdev)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
ERR_IF(!b) return 0;
|
|
ERR_IF(!b->bm_pages) return 0;
|
|
|
|
return b->bm_words;
|
|
}
|
|
|
|
unsigned long drbd_bm_bits(struct drbd_conf *mdev)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
ERR_IF(!b) return 0;
|
|
|
|
return b->bm_bits;
|
|
}
|
|
|
|
/* merge number words from buffer into the bitmap starting at offset.
|
|
* buffer[i] is expected to be little endian unsigned long.
|
|
* bitmap must be locked by drbd_bm_lock.
|
|
* currently only used from receive_bitmap.
|
|
*/
|
|
void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number,
|
|
unsigned long *buffer)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long *p_addr, *bm;
|
|
unsigned long word, bits;
|
|
size_t end, do_now;
|
|
|
|
end = offset + number;
|
|
|
|
ERR_IF(!b) return;
|
|
ERR_IF(!b->bm_pages) return;
|
|
if (number == 0)
|
|
return;
|
|
WARN_ON(offset >= b->bm_words);
|
|
WARN_ON(end > b->bm_words);
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
while (offset < end) {
|
|
do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset;
|
|
p_addr = bm_map_paddr(b, offset);
|
|
bm = p_addr + MLPP(offset);
|
|
offset += do_now;
|
|
while (do_now--) {
|
|
bits = hweight_long(*bm);
|
|
word = *bm | lel_to_cpu(*buffer++);
|
|
*bm++ = word;
|
|
b->bm_set += hweight_long(word) - bits;
|
|
}
|
|
bm_unmap(p_addr);
|
|
}
|
|
/* with 32bit <-> 64bit cross-platform connect
|
|
* this is only correct for current usage,
|
|
* where we _know_ that we are 64 bit aligned,
|
|
* and know that this function is used in this way, too...
|
|
*/
|
|
if (end == b->bm_words)
|
|
b->bm_set -= bm_clear_surplus(b);
|
|
|
|
spin_unlock_irq(&b->bm_lock);
|
|
}
|
|
|
|
/* copy number words from the bitmap starting at offset into the buffer.
|
|
* buffer[i] will be little endian unsigned long.
|
|
*/
|
|
void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number,
|
|
unsigned long *buffer)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long *p_addr, *bm;
|
|
size_t end, do_now;
|
|
|
|
end = offset + number;
|
|
|
|
ERR_IF(!b) return;
|
|
ERR_IF(!b->bm_pages) return;
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
if ((offset >= b->bm_words) ||
|
|
(end > b->bm_words) ||
|
|
(number <= 0))
|
|
dev_err(DEV, "offset=%lu number=%lu bm_words=%lu\n",
|
|
(unsigned long) offset,
|
|
(unsigned long) number,
|
|
(unsigned long) b->bm_words);
|
|
else {
|
|
while (offset < end) {
|
|
do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset;
|
|
p_addr = bm_map_paddr(b, offset);
|
|
bm = p_addr + MLPP(offset);
|
|
offset += do_now;
|
|
while (do_now--)
|
|
*buffer++ = cpu_to_lel(*bm++);
|
|
bm_unmap(p_addr);
|
|
}
|
|
}
|
|
spin_unlock_irq(&b->bm_lock);
|
|
}
|
|
|
|
/* set all bits in the bitmap */
|
|
void drbd_bm_set_all(struct drbd_conf *mdev)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
ERR_IF(!b) return;
|
|
ERR_IF(!b->bm_pages) return;
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
bm_memset(b, 0, 0xff, b->bm_words);
|
|
(void)bm_clear_surplus(b);
|
|
b->bm_set = b->bm_bits;
|
|
spin_unlock_irq(&b->bm_lock);
|
|
}
|
|
|
|
/* clear all bits in the bitmap */
|
|
void drbd_bm_clear_all(struct drbd_conf *mdev)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
ERR_IF(!b) return;
|
|
ERR_IF(!b->bm_pages) return;
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
bm_memset(b, 0, 0, b->bm_words);
|
|
b->bm_set = 0;
|
|
spin_unlock_irq(&b->bm_lock);
|
|
}
|
|
|
|
static void bm_async_io_complete(struct bio *bio, int error)
|
|
{
|
|
struct drbd_bitmap *b = bio->bi_private;
|
|
int uptodate = bio_flagged(bio, BIO_UPTODATE);
|
|
|
|
|
|
/* strange behavior of some lower level drivers...
|
|
* fail the request by clearing the uptodate flag,
|
|
* but do not return any error?!
|
|
* do we want to WARN() on this? */
|
|
if (!error && !uptodate)
|
|
error = -EIO;
|
|
|
|
if (error) {
|
|
/* doh. what now?
|
|
* for now, set all bits, and flag MD_IO_ERROR */
|
|
__set_bit(BM_MD_IO_ERROR, &b->bm_flags);
|
|
}
|
|
if (atomic_dec_and_test(&b->bm_async_io))
|
|
wake_up(&b->bm_io_wait);
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int page_nr, int rw) __must_hold(local)
|
|
{
|
|
/* we are process context. we always get a bio */
|
|
struct bio *bio = bio_alloc(GFP_KERNEL, 1);
|
|
unsigned int len;
|
|
sector_t on_disk_sector =
|
|
mdev->ldev->md.md_offset + mdev->ldev->md.bm_offset;
|
|
on_disk_sector += ((sector_t)page_nr) << (PAGE_SHIFT-9);
|
|
|
|
/* this might happen with very small
|
|
* flexible external meta data device */
|
|
len = min_t(unsigned int, PAGE_SIZE,
|
|
(drbd_md_last_sector(mdev->ldev) - on_disk_sector + 1)<<9);
|
|
|
|
bio->bi_bdev = mdev->ldev->md_bdev;
|
|
bio->bi_sector = on_disk_sector;
|
|
bio_add_page(bio, b->bm_pages[page_nr], len, 0);
|
|
bio->bi_private = b;
|
|
bio->bi_end_io = bm_async_io_complete;
|
|
|
|
if (FAULT_ACTIVE(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) {
|
|
bio->bi_rw |= rw;
|
|
bio_endio(bio, -EIO);
|
|
} else {
|
|
submit_bio(rw, bio);
|
|
}
|
|
}
|
|
|
|
# if defined(__LITTLE_ENDIAN)
|
|
/* nothing to do, on disk == in memory */
|
|
# define bm_cpu_to_lel(x) ((void)0)
|
|
# else
|
|
static void bm_cpu_to_lel(struct drbd_bitmap *b)
|
|
{
|
|
/* need to cpu_to_lel all the pages ...
|
|
* this may be optimized by using
|
|
* cpu_to_lel(-1) == -1 and cpu_to_lel(0) == 0;
|
|
* the following is still not optimal, but better than nothing */
|
|
unsigned int i;
|
|
unsigned long *p_addr, *bm;
|
|
if (b->bm_set == 0) {
|
|
/* no page at all; avoid swap if all is 0 */
|
|
i = b->bm_number_of_pages;
|
|
} else if (b->bm_set == b->bm_bits) {
|
|
/* only the last page */
|
|
i = b->bm_number_of_pages - 1;
|
|
} else {
|
|
/* all pages */
|
|
i = 0;
|
|
}
|
|
for (; i < b->bm_number_of_pages; i++) {
|
|
p_addr = kmap_atomic(b->bm_pages[i], KM_USER0);
|
|
for (bm = p_addr; bm < p_addr + PAGE_SIZE/sizeof(long); bm++)
|
|
*bm = cpu_to_lel(*bm);
|
|
kunmap_atomic(p_addr, KM_USER0);
|
|
}
|
|
}
|
|
# endif
|
|
/* lel_to_cpu == cpu_to_lel */
|
|
# define bm_lel_to_cpu(x) bm_cpu_to_lel(x)
|
|
|
|
/*
|
|
* bm_rw: read/write the whole bitmap from/to its on disk location.
|
|
*/
|
|
static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
/* sector_t sector; */
|
|
int bm_words, num_pages, i;
|
|
unsigned long now;
|
|
char ppb[10];
|
|
int err = 0;
|
|
|
|
WARN_ON(!bm_is_locked(b));
|
|
|
|
/* no spinlock here, the drbd_bm_lock should be enough! */
|
|
|
|
bm_words = drbd_bm_words(mdev);
|
|
num_pages = (bm_words*sizeof(long) + PAGE_SIZE-1) >> PAGE_SHIFT;
|
|
|
|
/* on disk bitmap is little endian */
|
|
if (rw == WRITE)
|
|
bm_cpu_to_lel(b);
|
|
|
|
now = jiffies;
|
|
atomic_set(&b->bm_async_io, num_pages);
|
|
__clear_bit(BM_MD_IO_ERROR, &b->bm_flags);
|
|
|
|
/* let the layers below us try to merge these bios... */
|
|
for (i = 0; i < num_pages; i++)
|
|
bm_page_io_async(mdev, b, i, rw);
|
|
|
|
drbd_blk_run_queue(bdev_get_queue(mdev->ldev->md_bdev));
|
|
wait_event(b->bm_io_wait, atomic_read(&b->bm_async_io) == 0);
|
|
|
|
if (test_bit(BM_MD_IO_ERROR, &b->bm_flags)) {
|
|
dev_alert(DEV, "we had at least one MD IO ERROR during bitmap IO\n");
|
|
drbd_chk_io_error(mdev, 1, TRUE);
|
|
err = -EIO;
|
|
}
|
|
|
|
now = jiffies;
|
|
if (rw == WRITE) {
|
|
/* swap back endianness */
|
|
bm_lel_to_cpu(b);
|
|
/* flush bitmap to stable storage */
|
|
drbd_md_flush(mdev);
|
|
} else /* rw == READ */ {
|
|
/* just read, if necessary adjust endianness */
|
|
b->bm_set = bm_count_bits_swap_endian(b);
|
|
dev_info(DEV, "recounting of set bits took additional %lu jiffies\n",
|
|
jiffies - now);
|
|
}
|
|
now = b->bm_set;
|
|
|
|
dev_info(DEV, "%s (%lu bits) marked out-of-sync by on disk bit-map.\n",
|
|
ppsize(ppb, now << (BM_BLOCK_SHIFT-10)), now);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* drbd_bm_read() - Read the whole bitmap from its on disk location.
|
|
* @mdev: DRBD device.
|
|
*/
|
|
int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local)
|
|
{
|
|
return bm_rw(mdev, READ);
|
|
}
|
|
|
|
/**
|
|
* drbd_bm_write() - Write the whole bitmap to its on disk location.
|
|
* @mdev: DRBD device.
|
|
*/
|
|
int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local)
|
|
{
|
|
return bm_rw(mdev, WRITE);
|
|
}
|
|
|
|
/**
|
|
* drbd_bm_write_sect: Writes a 512 (MD_SECTOR_SIZE) byte piece of the bitmap
|
|
* @mdev: DRBD device.
|
|
* @enr: Extent number in the resync lru (happens to be sector offset)
|
|
*
|
|
* The BM_EXT_SIZE is on purpose exactly the amount of the bitmap covered
|
|
* by a single sector write. Therefore enr == sector offset from the
|
|
* start of the bitmap.
|
|
*/
|
|
int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local)
|
|
{
|
|
sector_t on_disk_sector = enr + mdev->ldev->md.md_offset
|
|
+ mdev->ldev->md.bm_offset;
|
|
int bm_words, num_words, offset;
|
|
int err = 0;
|
|
|
|
mutex_lock(&mdev->md_io_mutex);
|
|
bm_words = drbd_bm_words(mdev);
|
|
offset = S2W(enr); /* word offset into bitmap */
|
|
num_words = min(S2W(1), bm_words - offset);
|
|
if (num_words < S2W(1))
|
|
memset(page_address(mdev->md_io_page), 0, MD_SECTOR_SIZE);
|
|
drbd_bm_get_lel(mdev, offset, num_words,
|
|
page_address(mdev->md_io_page));
|
|
if (!drbd_md_sync_page_io(mdev, mdev->ldev, on_disk_sector, WRITE)) {
|
|
int i;
|
|
err = -EIO;
|
|
dev_err(DEV, "IO ERROR writing bitmap sector %lu "
|
|
"(meta-disk sector %llus)\n",
|
|
enr, (unsigned long long)on_disk_sector);
|
|
drbd_chk_io_error(mdev, 1, TRUE);
|
|
for (i = 0; i < AL_EXT_PER_BM_SECT; i++)
|
|
drbd_bm_ALe_set_all(mdev, enr*AL_EXT_PER_BM_SECT+i);
|
|
}
|
|
mdev->bm_writ_cnt++;
|
|
mutex_unlock(&mdev->md_io_mutex);
|
|
return err;
|
|
}
|
|
|
|
/* NOTE
|
|
* find_first_bit returns int, we return unsigned long.
|
|
* should not make much difference anyways, but ...
|
|
*
|
|
* this returns a bit number, NOT a sector!
|
|
*/
|
|
#define BPP_MASK ((1UL << (PAGE_SHIFT+3)) - 1)
|
|
static unsigned long __bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo,
|
|
const int find_zero_bit, const enum km_type km)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long i = -1UL;
|
|
unsigned long *p_addr;
|
|
unsigned long bit_offset; /* bit offset of the mapped page. */
|
|
|
|
if (bm_fo > b->bm_bits) {
|
|
dev_err(DEV, "bm_fo=%lu bm_bits=%lu\n", bm_fo, b->bm_bits);
|
|
} else {
|
|
while (bm_fo < b->bm_bits) {
|
|
unsigned long offset;
|
|
bit_offset = bm_fo & ~BPP_MASK; /* bit offset of the page */
|
|
offset = bit_offset >> LN2_BPL; /* word offset of the page */
|
|
p_addr = __bm_map_paddr(b, offset, km);
|
|
|
|
if (find_zero_bit)
|
|
i = find_next_zero_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK);
|
|
else
|
|
i = find_next_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK);
|
|
|
|
__bm_unmap(p_addr, km);
|
|
if (i < PAGE_SIZE*8) {
|
|
i = bit_offset + i;
|
|
if (i >= b->bm_bits)
|
|
break;
|
|
goto found;
|
|
}
|
|
bm_fo = bit_offset + PAGE_SIZE*8;
|
|
}
|
|
i = -1UL;
|
|
}
|
|
found:
|
|
return i;
|
|
}
|
|
|
|
static unsigned long bm_find_next(struct drbd_conf *mdev,
|
|
unsigned long bm_fo, const int find_zero_bit)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long i = -1UL;
|
|
|
|
ERR_IF(!b) return i;
|
|
ERR_IF(!b->bm_pages) return i;
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
if (bm_is_locked(b))
|
|
bm_print_lock_info(mdev);
|
|
|
|
i = __bm_find_next(mdev, bm_fo, find_zero_bit, KM_IRQ1);
|
|
|
|
spin_unlock_irq(&b->bm_lock);
|
|
return i;
|
|
}
|
|
|
|
unsigned long drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo)
|
|
{
|
|
return bm_find_next(mdev, bm_fo, 0);
|
|
}
|
|
|
|
#if 0
|
|
/* not yet needed for anything. */
|
|
unsigned long drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo)
|
|
{
|
|
return bm_find_next(mdev, bm_fo, 1);
|
|
}
|
|
#endif
|
|
|
|
/* does not spin_lock_irqsave.
|
|
* you must take drbd_bm_lock() first */
|
|
unsigned long _drbd_bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo)
|
|
{
|
|
/* WARN_ON(!bm_is_locked(mdev)); */
|
|
return __bm_find_next(mdev, bm_fo, 0, KM_USER1);
|
|
}
|
|
|
|
unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_fo)
|
|
{
|
|
/* WARN_ON(!bm_is_locked(mdev)); */
|
|
return __bm_find_next(mdev, bm_fo, 1, KM_USER1);
|
|
}
|
|
|
|
/* returns number of bits actually changed.
|
|
* for val != 0, we change 0 -> 1, return code positive
|
|
* for val == 0, we change 1 -> 0, return code negative
|
|
* wants bitnr, not sector.
|
|
* expected to be called for only a few bits (e - s about BITS_PER_LONG).
|
|
* Must hold bitmap lock already. */
|
|
static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
|
|
unsigned long e, int val, const enum km_type km)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long *p_addr = NULL;
|
|
unsigned long bitnr;
|
|
unsigned long last_page_nr = -1UL;
|
|
int c = 0;
|
|
|
|
if (e >= b->bm_bits) {
|
|
dev_err(DEV, "ASSERT FAILED: bit_s=%lu bit_e=%lu bm_bits=%lu\n",
|
|
s, e, b->bm_bits);
|
|
e = b->bm_bits ? b->bm_bits -1 : 0;
|
|
}
|
|
for (bitnr = s; bitnr <= e; bitnr++) {
|
|
unsigned long offset = bitnr>>LN2_BPL;
|
|
unsigned long page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3);
|
|
if (page_nr != last_page_nr) {
|
|
if (p_addr)
|
|
__bm_unmap(p_addr, km);
|
|
p_addr = __bm_map_paddr(b, offset, km);
|
|
last_page_nr = page_nr;
|
|
}
|
|
if (val)
|
|
c += (0 == __test_and_set_bit(bitnr & BPP_MASK, p_addr));
|
|
else
|
|
c -= (0 != __test_and_clear_bit(bitnr & BPP_MASK, p_addr));
|
|
}
|
|
if (p_addr)
|
|
__bm_unmap(p_addr, km);
|
|
b->bm_set += c;
|
|
return c;
|
|
}
|
|
|
|
/* returns number of bits actually changed.
|
|
* for val != 0, we change 0 -> 1, return code positive
|
|
* for val == 0, we change 1 -> 0, return code negative
|
|
* wants bitnr, not sector */
|
|
static int bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
|
|
const unsigned long e, int val)
|
|
{
|
|
unsigned long flags;
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
int c = 0;
|
|
|
|
ERR_IF(!b) return 1;
|
|
ERR_IF(!b->bm_pages) return 0;
|
|
|
|
spin_lock_irqsave(&b->bm_lock, flags);
|
|
if (bm_is_locked(b))
|
|
bm_print_lock_info(mdev);
|
|
|
|
c = __bm_change_bits_to(mdev, s, e, val, KM_IRQ1);
|
|
|
|
spin_unlock_irqrestore(&b->bm_lock, flags);
|
|
return c;
|
|
}
|
|
|
|
/* returns number of bits changed 0 -> 1 */
|
|
int drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e)
|
|
{
|
|
return bm_change_bits_to(mdev, s, e, 1);
|
|
}
|
|
|
|
/* returns number of bits changed 1 -> 0 */
|
|
int drbd_bm_clear_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e)
|
|
{
|
|
return -bm_change_bits_to(mdev, s, e, 0);
|
|
}
|
|
|
|
/* sets all bits in full words,
|
|
* from first_word up to, but not including, last_word */
|
|
static inline void bm_set_full_words_within_one_page(struct drbd_bitmap *b,
|
|
int page_nr, int first_word, int last_word)
|
|
{
|
|
int i;
|
|
int bits;
|
|
unsigned long *paddr = kmap_atomic(b->bm_pages[page_nr], KM_USER0);
|
|
for (i = first_word; i < last_word; i++) {
|
|
bits = hweight_long(paddr[i]);
|
|
paddr[i] = ~0UL;
|
|
b->bm_set += BITS_PER_LONG - bits;
|
|
}
|
|
kunmap_atomic(paddr, KM_USER0);
|
|
}
|
|
|
|
/* Same thing as drbd_bm_set_bits, but without taking the spin_lock_irqsave.
|
|
* You must first drbd_bm_lock().
|
|
* Can be called to set the whole bitmap in one go.
|
|
* Sets bits from s to e _inclusive_. */
|
|
void _drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e)
|
|
{
|
|
/* First set_bit from the first bit (s)
|
|
* up to the next long boundary (sl),
|
|
* then assign full words up to the last long boundary (el),
|
|
* then set_bit up to and including the last bit (e).
|
|
*
|
|
* Do not use memset, because we must account for changes,
|
|
* so we need to loop over the words with hweight() anyways.
|
|
*/
|
|
unsigned long sl = ALIGN(s,BITS_PER_LONG);
|
|
unsigned long el = (e+1) & ~((unsigned long)BITS_PER_LONG-1);
|
|
int first_page;
|
|
int last_page;
|
|
int page_nr;
|
|
int first_word;
|
|
int last_word;
|
|
|
|
if (e - s <= 3*BITS_PER_LONG) {
|
|
/* don't bother; el and sl may even be wrong. */
|
|
__bm_change_bits_to(mdev, s, e, 1, KM_USER0);
|
|
return;
|
|
}
|
|
|
|
/* difference is large enough that we can trust sl and el */
|
|
|
|
/* bits filling the current long */
|
|
if (sl)
|
|
__bm_change_bits_to(mdev, s, sl-1, 1, KM_USER0);
|
|
|
|
first_page = sl >> (3 + PAGE_SHIFT);
|
|
last_page = el >> (3 + PAGE_SHIFT);
|
|
|
|
/* MLPP: modulo longs per page */
|
|
/* LWPP: long words per page */
|
|
first_word = MLPP(sl >> LN2_BPL);
|
|
last_word = LWPP;
|
|
|
|
/* first and full pages, unless first page == last page */
|
|
for (page_nr = first_page; page_nr < last_page; page_nr++) {
|
|
bm_set_full_words_within_one_page(mdev->bitmap, page_nr, first_word, last_word);
|
|
cond_resched();
|
|
first_word = 0;
|
|
}
|
|
|
|
/* last page (respectively only page, for first page == last page) */
|
|
last_word = MLPP(el >> LN2_BPL);
|
|
bm_set_full_words_within_one_page(mdev->bitmap, last_page, first_word, last_word);
|
|
|
|
/* possibly trailing bits.
|
|
* example: (e & 63) == 63, el will be e+1.
|
|
* if that even was the very last bit,
|
|
* it would trigger an assert in __bm_change_bits_to()
|
|
*/
|
|
if (el <= e)
|
|
__bm_change_bits_to(mdev, el, e, 1, KM_USER0);
|
|
}
|
|
|
|
/* returns bit state
|
|
* wants bitnr, NOT sector.
|
|
* inherently racy... area needs to be locked by means of {al,rs}_lru
|
|
* 1 ... bit set
|
|
* 0 ... bit not set
|
|
* -1 ... first out of bounds access, stop testing for bits!
|
|
*/
|
|
int drbd_bm_test_bit(struct drbd_conf *mdev, const unsigned long bitnr)
|
|
{
|
|
unsigned long flags;
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long *p_addr;
|
|
int i;
|
|
|
|
ERR_IF(!b) return 0;
|
|
ERR_IF(!b->bm_pages) return 0;
|
|
|
|
spin_lock_irqsave(&b->bm_lock, flags);
|
|
if (bm_is_locked(b))
|
|
bm_print_lock_info(mdev);
|
|
if (bitnr < b->bm_bits) {
|
|
unsigned long offset = bitnr>>LN2_BPL;
|
|
p_addr = bm_map_paddr(b, offset);
|
|
i = test_bit(bitnr & BPP_MASK, p_addr) ? 1 : 0;
|
|
bm_unmap(p_addr);
|
|
} else if (bitnr == b->bm_bits) {
|
|
i = -1;
|
|
} else { /* (bitnr > b->bm_bits) */
|
|
dev_err(DEV, "bitnr=%lu > bm_bits=%lu\n", bitnr, b->bm_bits);
|
|
i = 0;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&b->bm_lock, flags);
|
|
return i;
|
|
}
|
|
|
|
/* returns number of bits set in the range [s, e] */
|
|
int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e)
|
|
{
|
|
unsigned long flags;
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long *p_addr = NULL, page_nr = -1;
|
|
unsigned long bitnr;
|
|
int c = 0;
|
|
size_t w;
|
|
|
|
/* If this is called without a bitmap, that is a bug. But just to be
|
|
* robust in case we screwed up elsewhere, in that case pretend there
|
|
* was one dirty bit in the requested area, so we won't try to do a
|
|
* local read there (no bitmap probably implies no disk) */
|
|
ERR_IF(!b) return 1;
|
|
ERR_IF(!b->bm_pages) return 1;
|
|
|
|
spin_lock_irqsave(&b->bm_lock, flags);
|
|
if (bm_is_locked(b))
|
|
bm_print_lock_info(mdev);
|
|
for (bitnr = s; bitnr <= e; bitnr++) {
|
|
w = bitnr >> LN2_BPL;
|
|
if (page_nr != w >> (PAGE_SHIFT - LN2_BPL + 3)) {
|
|
page_nr = w >> (PAGE_SHIFT - LN2_BPL + 3);
|
|
if (p_addr)
|
|
bm_unmap(p_addr);
|
|
p_addr = bm_map_paddr(b, w);
|
|
}
|
|
ERR_IF (bitnr >= b->bm_bits) {
|
|
dev_err(DEV, "bitnr=%lu bm_bits=%lu\n", bitnr, b->bm_bits);
|
|
} else {
|
|
c += (0 != test_bit(bitnr - (page_nr << (PAGE_SHIFT+3)), p_addr));
|
|
}
|
|
}
|
|
if (p_addr)
|
|
bm_unmap(p_addr);
|
|
spin_unlock_irqrestore(&b->bm_lock, flags);
|
|
return c;
|
|
}
|
|
|
|
|
|
/* inherently racy...
|
|
* return value may be already out-of-date when this function returns.
|
|
* but the general usage is that this is only use during a cstate when bits are
|
|
* only cleared, not set, and typically only care for the case when the return
|
|
* value is zero, or we already "locked" this "bitmap extent" by other means.
|
|
*
|
|
* enr is bm-extent number, since we chose to name one sector (512 bytes)
|
|
* worth of the bitmap a "bitmap extent".
|
|
*
|
|
* TODO
|
|
* I think since we use it like a reference count, we should use the real
|
|
* reference count of some bitmap extent element from some lru instead...
|
|
*
|
|
*/
|
|
int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
int count, s, e;
|
|
unsigned long flags;
|
|
unsigned long *p_addr, *bm;
|
|
|
|
ERR_IF(!b) return 0;
|
|
ERR_IF(!b->bm_pages) return 0;
|
|
|
|
spin_lock_irqsave(&b->bm_lock, flags);
|
|
if (bm_is_locked(b))
|
|
bm_print_lock_info(mdev);
|
|
|
|
s = S2W(enr);
|
|
e = min((size_t)S2W(enr+1), b->bm_words);
|
|
count = 0;
|
|
if (s < b->bm_words) {
|
|
int n = e-s;
|
|
p_addr = bm_map_paddr(b, s);
|
|
bm = p_addr + MLPP(s);
|
|
while (n--)
|
|
count += hweight_long(*bm++);
|
|
bm_unmap(p_addr);
|
|
} else {
|
|
dev_err(DEV, "start offset (%d) too large in drbd_bm_e_weight\n", s);
|
|
}
|
|
spin_unlock_irqrestore(&b->bm_lock, flags);
|
|
return count;
|
|
}
|
|
|
|
/* set all bits covered by the AL-extent al_enr */
|
|
unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, unsigned long al_enr)
|
|
{
|
|
struct drbd_bitmap *b = mdev->bitmap;
|
|
unsigned long *p_addr, *bm;
|
|
unsigned long weight;
|
|
int count, s, e, i, do_now;
|
|
ERR_IF(!b) return 0;
|
|
ERR_IF(!b->bm_pages) return 0;
|
|
|
|
spin_lock_irq(&b->bm_lock);
|
|
if (bm_is_locked(b))
|
|
bm_print_lock_info(mdev);
|
|
weight = b->bm_set;
|
|
|
|
s = al_enr * BM_WORDS_PER_AL_EXT;
|
|
e = min_t(size_t, s + BM_WORDS_PER_AL_EXT, b->bm_words);
|
|
/* assert that s and e are on the same page */
|
|
D_ASSERT((e-1) >> (PAGE_SHIFT - LN2_BPL + 3)
|
|
== s >> (PAGE_SHIFT - LN2_BPL + 3));
|
|
count = 0;
|
|
if (s < b->bm_words) {
|
|
i = do_now = e-s;
|
|
p_addr = bm_map_paddr(b, s);
|
|
bm = p_addr + MLPP(s);
|
|
while (i--) {
|
|
count += hweight_long(*bm);
|
|
*bm = -1UL;
|
|
bm++;
|
|
}
|
|
bm_unmap(p_addr);
|
|
b->bm_set += do_now*BITS_PER_LONG - count;
|
|
if (e == b->bm_words)
|
|
b->bm_set -= bm_clear_surplus(b);
|
|
} else {
|
|
dev_err(DEV, "start offset (%d) too large in drbd_bm_ALe_set_all\n", s);
|
|
}
|
|
weight = b->bm_set - weight;
|
|
spin_unlock_irq(&b->bm_lock);
|
|
return weight;
|
|
}
|