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drbd: bitmap keep track of changes vs on-disk bitmap 

When we set or clear bits in a bitmap page,
also set a flag in the page->private pointer.

This allows us to skip writes of unchanged pages.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
hifive-unleashed-5.1
Lars Ellenberg 2010-12-15 08:59:11 +01:00 committed by Philipp Reisner
parent 95a0f10cdd
commit 19f843aa08
6 changed files with 374 additions and 221 deletions
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132
drivers/block/drbd/drbd_actlog.c
View File

@ -262,6 +262,33 @@ void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector)
spin_unlock_irqrestore(&mdev->al_lock, flags);
}
#if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)
/* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT
* are still coupled, or assume too much about their relation.
* Code below will not work if this is violated.
* Will be cleaned up with some followup patch.
*/
# error FIXME
#endif
static unsigned int al_extent_to_bm_page(unsigned int al_enr)
{
return al_enr >>
/* bit to page */
((PAGE_SHIFT + 3) -
/* al extent number to bit */
(AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));
}
static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
{
return rs_enr >>
/* bit to page */
((PAGE_SHIFT + 3) -
/* al extent number to bit */
(BM_EXT_SHIFT - BM_BLOCK_SHIFT));
}
int
w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
@ -289,7 +316,7 @@ w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused)
* For now, we must not write the transaction,
* if we cannot write out the bitmap of the evicted extent. */
if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE)
drbd_bm_write_sect(mdev, evicted/AL_EXT_PER_BM_SECT);
drbd_bm_write_page(mdev, al_extent_to_bm_page(evicted));
/* The bitmap write may have failed, causing a state change. */
if (mdev->state.disk < D_INCONSISTENT) {
@ -635,105 +662,6 @@ out_bio_put:
return err;
}
/**
* drbd_al_to_on_disk_bm() - * Writes bitmap parts covered by active AL extents
* @mdev: DRBD device.
*
* Called when we detach (unconfigure) local storage,
* or when we go from R_PRIMARY to R_SECONDARY role.
*/
void drbd_al_to_on_disk_bm(struct drbd_conf *mdev)
{
int i, nr_elements;
unsigned int enr;
struct bio **bios;
struct drbd_atodb_wait wc;
ERR_IF (!get_ldev_if_state(mdev, D_ATTACHING))
return; /* sorry, I don't have any act_log etc... */
wait_event(mdev->al_wait, lc_try_lock(mdev->act_log));
nr_elements = mdev->act_log->nr_elements;
/* GFP_KERNEL, we are not in anyone's write-out path */
bios = kzalloc(sizeof(struct bio *) * nr_elements, GFP_KERNEL);
if (!bios)
goto submit_one_by_one;
atomic_set(&wc.count, 0);
init_completion(&wc.io_done);
wc.mdev = mdev;
wc.error = 0;
for (i = 0; i < nr_elements; i++) {
enr = lc_element_by_index(mdev->act_log, i)->lc_number;
if (enr == LC_FREE)
continue;
/* next statement also does atomic_inc wc.count and local_cnt */
if (atodb_prepare_unless_covered(mdev, bios,
enr/AL_EXT_PER_BM_SECT,
&wc))
goto free_bios_submit_one_by_one;
}
/* unnecessary optimization? */
lc_unlock(mdev->act_log);
wake_up(&mdev->al_wait);
/* all prepared, submit them */
for (i = 0; i < nr_elements; i++) {
if (bios[i] == NULL)
break;
if (drbd_insert_fault(mdev, DRBD_FAULT_MD_WR)) {
bios[i]->bi_rw = WRITE;
bio_endio(bios[i], -EIO);
} else {
submit_bio(WRITE, bios[i]);
}
}
/* always (try to) flush bitmap to stable storage */
drbd_md_flush(mdev);
/* In case we did not submit a single IO do not wait for
* them to complete. ( Because we would wait forever here. )
*
* In case we had IOs and they are already complete, there
* is not point in waiting anyways.
* Therefore this if () ... */
if (atomic_read(&wc.count))
wait_for_completion(&wc.io_done);
put_ldev(mdev);
kfree(bios);
return;
free_bios_submit_one_by_one:
/* free everything by calling the endio callback directly. */
for (i = 0; i < nr_elements && bios[i]; i++)
bio_endio(bios[i], 0);
kfree(bios);
submit_one_by_one:
dev_warn(DEV, "Using the slow drbd_al_to_on_disk_bm()\n");
for (i = 0; i < mdev->act_log->nr_elements; i++) {
enr = lc_element_by_index(mdev->act_log, i)->lc_number;
if (enr == LC_FREE)
continue;
/* Really slow: if we have al-extents 16..19 active,
* sector 4 will be written four times! Synchronous! */
drbd_bm_write_sect(mdev, enr/AL_EXT_PER_BM_SECT);
}
lc_unlock(mdev->act_log);
wake_up(&mdev->al_wait);
put_ldev(mdev);
}
/**
* drbd_al_apply_to_bm() - Sets the bitmap to diry(1) where covered ba active AL extents
* @mdev: DRBD device.
@ -813,7 +741,7 @@ static int w_update_odbm(struct drbd_conf *mdev, struct drbd_work *w, int unused
return 1;
}
drbd_bm_write_sect(mdev, udw->enr);
drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr));
put_ldev(mdev);
kfree(udw);
@ -893,7 +821,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector,
dev_warn(DEV, "Kicking resync_lru element enr=%u "
"out with rs_failed=%d\n",
ext->lce.lc_number, ext->rs_failed);
set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags);
}
ext->rs_left = rs_left;
ext->rs_failed = success ? 0 : count;
@ -912,7 +839,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector,
drbd_queue_work_front(&mdev->data.work, &udw->w);
} else {
dev_warn(DEV, "Could not kmalloc an udw\n");
set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags);
}
}
} else {

411
drivers/block/drbd/drbd_bitmap.c
View File

@ -70,8 +70,7 @@ struct drbd_bitmap {
sector_t bm_dev_capacity;
struct mutex bm_change; /* serializes resize operations */
atomic_t bm_async_io;
wait_queue_head_t bm_io_wait;
wait_queue_head_t bm_io_wait; /* used to serialize IO of single pages */
unsigned long bm_flags;
@ -82,7 +81,7 @@ struct drbd_bitmap {
/* definition of bits in bm_flags */
#define BM_LOCKED 0
#define BM_MD_IO_ERROR 1
// #define BM_MD_IO_ERROR 1 unused now.
#define BM_P_VMALLOCED 2
static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
@ -155,26 +154,117 @@ void drbd_bm_unlock(struct drbd_conf *mdev)
mutex_unlock(&b->bm_change);
}
static unsigned int bm_bit_to_page_idx(struct drbd_bitmap *b, u64 bitnr)
/* we store some "meta" info about our pages in page->private */
/* at a granularity of 4k storage per bitmap bit:
* one peta byte storage: 1<<50 byte, 1<<38 * 4k storage blocks
* 1<<38 bits,
* 1<<23 4k bitmap pages.
* Use 24 bits as page index, covers 2 peta byte storage
* at a granularity of 4k per bit.
* Used to report the failed page idx on io error from the endio handlers.
*/
#define BM_PAGE_IDX_MASK ((1UL<<24)-1)
/* this page is currently read in, or written back */
#define BM_PAGE_IO_LOCK 31
/* if there has been an IO error for this page */
#define BM_PAGE_IO_ERROR 30
/* this is to be able to intelligently skip disk IO,
* set if bits have been set since last IO. */
#define BM_PAGE_NEED_WRITEOUT 29
/* 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
/* store_page_idx uses non-atomic assingment. It is only used directly after
* allocating the page. All other bm_set_page_* and bm_clear_page_* need to
* use atomic bit manipulation, as set_out_of_sync (and therefore bitmap
* changes) may happen from various contexts, and wait_on_bit/wake_up_bit
* requires it all to be atomic as well. */
static void bm_store_page_idx(struct page *page, unsigned long idx)
{
/* page_nr = (bitnr/8) >> PAGE_SHIFT; */
unsigned int page_nr = bitnr >> (PAGE_SHIFT + 3);
BUG_ON(page_nr >= b->bm_number_of_pages);
return page_nr;
BUG_ON(0 != (idx & ~BM_PAGE_IDX_MASK));
page_private(page) |= idx;
}
/* word offset to long pointer */
static unsigned long *__bm_map_paddr(struct drbd_bitmap *b, unsigned long offset, const enum km_type km)
static unsigned long bm_page_to_idx(struct page *page)
{
struct page *page;
unsigned long page_nr;
return page_private(page) & BM_PAGE_IDX_MASK;
}
/* As is very unlikely that the same page is under IO from more than one
* context, we can get away with a bit per page and one wait queue per bitmap.
*/
static void bm_page_lock_io(struct drbd_conf *mdev, int page_nr)
{
struct drbd_bitmap *b = mdev->bitmap;
void *addr = &page_private(b->bm_pages[page_nr]);
wait_event(b->bm_io_wait, !test_and_set_bit(BM_PAGE_IO_LOCK, addr));
}
static void bm_page_unlock_io(struct drbd_conf *mdev, int page_nr)
{
struct drbd_bitmap *b = mdev->bitmap;
void *addr = &page_private(b->bm_pages[page_nr]);
clear_bit(BM_PAGE_IO_LOCK, addr);
smp_mb__after_clear_bit();
wake_up(&mdev->bitmap->bm_io_wait);
}
/* set _before_ submit_io, so it may be reset due to being changed
* while this page is in flight... will get submitted later again */
static void bm_set_page_unchanged(struct page *page)
{
/* use cmpxchg? */
clear_bit(BM_PAGE_NEED_WRITEOUT, &page_private(page));
clear_bit(BM_PAGE_LAZY_WRITEOUT, &page_private(page));
}
static void bm_set_page_need_writeout(struct page *page)
{
set_bit(BM_PAGE_NEED_WRITEOUT, &page_private(page));
}
static int bm_test_page_unchanged(struct page *page)
{
volatile const unsigned long *addr = &page_private(page);
return (*addr & ((1UL<<BM_PAGE_NEED_WRITEOUT)|(1UL<<BM_PAGE_LAZY_WRITEOUT))) == 0;
}
static void bm_set_page_io_err(struct page *page)
{
set_bit(BM_PAGE_IO_ERROR, &page_private(page));
}
static void bm_clear_page_io_err(struct page *page)
{
clear_bit(BM_PAGE_IO_ERROR, &page_private(page));
}
static void bm_set_page_lazy_writeout(struct page *page)
{
set_bit(BM_PAGE_LAZY_WRITEOUT, &page_private(page));
}
static int bm_test_page_lazy_writeout(struct page *page)
{
return test_bit(BM_PAGE_LAZY_WRITEOUT, &page_private(page));
}
/* on a 32bit box, this would allow for exactly (2<<38) bits. */
static unsigned int bm_word_to_page_idx(struct drbd_bitmap *b, unsigned long long_nr)
{
/* page_nr = (word*sizeof(long)) >> PAGE_SHIFT; */
page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3);
unsigned int page_nr = long_nr >> (PAGE_SHIFT - LN2_BPL + 3);
BUG_ON(page_nr >= b->bm_number_of_pages);
page = b->bm_pages[page_nr];
return page_nr;
}
return (unsigned long *) kmap_atomic(page, km);
static unsigned int bm_bit_to_page_idx(struct drbd_bitmap *b, u64 bitnr)
{
/* page_nr = (bitnr/8) >> PAGE_SHIFT; */
unsigned int page_nr = bitnr >> (PAGE_SHIFT + 3);
BUG_ON(page_nr >= b->bm_number_of_pages);
return page_nr;
}
static unsigned long *__bm_map_pidx(struct drbd_bitmap *b, unsigned int idx, const enum km_type km)
@ -188,11 +278,6 @@ static unsigned long *bm_map_pidx(struct drbd_bitmap *b, unsigned int idx)
return __bm_map_pidx(b, idx, KM_IRQ1);
}
static unsigned long * bm_map_paddr(struct drbd_bitmap *b, unsigned long offset)
{
return __bm_map_paddr(b, offset, KM_IRQ1);
}
static void __bm_unmap(unsigned long *p_addr, const enum km_type km)
{
kunmap_atomic(p_addr, km);
@ -222,6 +307,7 @@ static void bm_unmap(unsigned long *p_addr)
* to be able to report device specific.
*/
static void bm_free_pages(struct page **pages, unsigned long number)
{
unsigned long i;
@ -289,6 +375,9 @@ static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want)
bm_vk_free(new_pages, vmalloced);
return NULL;
}
/* we want to know which page it is
* from the endio handlers */
bm_store_page_idx(page, i);
new_pages[i] = page;
}
} else {
@ -443,7 +532,7 @@ static unsigned long bm_count_bits(struct drbd_bitmap *b)
while (offset < words) {
i = do_now = min_t(size_t, words-offset, LWPP);
p_addr = __bm_map_paddr(b, offset, KM_USER0);
p_addr = __bm_map_pidx(b, bm_word_to_page_idx(b, offset), KM_USER0);
bm = p_addr + MLPP(offset);
while (i--) {
bits += hweight_long(*bm++);
@ -472,6 +561,7 @@ static unsigned long bm_count_bits(struct drbd_bitmap *b)
static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
{
unsigned long *p_addr, *bm;
unsigned int idx;
size_t do_now, end;
#define BM_SECTORS_PER_BIT (BM_BLOCK_SIZE/512)
@ -485,7 +575,8 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
while (offset < end) {
do_now = min_t(size_t, ALIGN(offset + 1, LWPP), end) - offset;
p_addr = bm_map_paddr(b, offset);
idx = bm_word_to_page_idx(b, offset);
p_addr = bm_map_pidx(b, idx);
bm = p_addr + MLPP(offset);
if (bm+do_now > p_addr + LWPP) {
printk(KERN_ALERT "drbd: BUG BUG BUG! p_addr:%p bm:%p do_now:%d\n",
@ -494,6 +585,7 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
}
memset(bm, c, do_now * sizeof(long));
bm_unmap(p_addr);
bm_set_page_need_writeout(b->bm_pages[idx]);
offset += do_now;
}
}
@ -604,7 +696,7 @@ 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_paddr(b, words);
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);
@ -616,7 +708,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits)
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);
dev_info(DEV, "resync bitmap: bits=%lu words=%lu pages=%lu\n", bits, words, want);
out:
drbd_bm_unlock(mdev);
@ -686,6 +778,7 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number,
struct drbd_bitmap *b = mdev->bitmap;
unsigned long *p_addr, *bm;
unsigned long word, bits;
unsigned int idx;
size_t end, do_now;
end = offset + number;
@ -700,7 +793,8 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number,
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);
idx = bm_word_to_page_idx(b, offset);
p_addr = bm_map_pidx(b, idx);
bm = p_addr + MLPP(offset);
offset += do_now;
while (do_now--) {
@ -710,6 +804,7 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number,
b->bm_set += hweight_long(word) - bits;
}
bm_unmap(p_addr);
bm_set_page_need_writeout(b->bm_pages[idx]);
}
/* with 32bit <-> 64bit cross-platform connect
* this is only correct for current usage,
@ -748,7 +843,7 @@ void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number,
else {
while (offset < end) {
do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset;
p_addr = bm_map_paddr(b, offset);
p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, offset));
bm = p_addr + MLPP(offset);
offset += do_now;
while (do_now--)
@ -786,9 +881,22 @@ void drbd_bm_clear_all(struct drbd_conf *mdev)
spin_unlock_irq(&b->bm_lock);
}
struct bm_aio_ctx {
struct drbd_conf *mdev;
atomic_t in_flight;
wait_queue_head_t io_wait;
unsigned flags;
#define BM_AIO_COPY_PAGES 1
int error;
};
/* bv_page may be a copy, or may be the original */
static void bm_async_io_complete(struct bio *bio, int error)
{
struct drbd_bitmap *b = bio->bi_private;
struct bm_aio_ctx *ctx = bio->bi_private;
struct drbd_conf *mdev = ctx->mdev;
struct drbd_bitmap *b = mdev->bitmap;
unsigned int idx = bm_page_to_idx(bio->bi_io_vec[0].bv_page);
int uptodate = bio_flagged(bio, BIO_UPTODATE);
@ -799,35 +907,79 @@ static void bm_async_io_complete(struct bio *bio, int error)
if (!error && !uptodate)
error = -EIO;
if (!bm_test_page_unchanged(b->bm_pages[idx]))
dev_info(DEV, "bitmap page idx %u changed during IO!\n", idx);
if (error) {
/* doh. what now?
* for now, set all bits, and flag MD_IO_ERROR */
__set_bit(BM_MD_IO_ERROR, &b->bm_flags);
/* ctx error will hold the completed-last non-zero error code,
* in case error codes differ. */
ctx->error = error;
bm_set_page_io_err(b->bm_pages[idx]);
/* Not identical to on disk version of it.
* Is BM_PAGE_IO_ERROR enough? */
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "IO ERROR %d on bitmap page idx %u\n",
error, idx);
} else {
bm_clear_page_io_err(b->bm_pages[idx]);
dynamic_dev_dbg(DEV, "bitmap page idx %u completed\n", idx);
}
if (atomic_dec_and_test(&b->bm_async_io))
wake_up(&b->bm_io_wait);
bm_page_unlock_io(mdev, idx);
/* FIXME give back to page pool */
if (ctx->flags & BM_AIO_COPY_PAGES)
put_page(bio->bi_io_vec[0].bv_page);
bio_put(bio);
if (atomic_dec_and_test(&ctx->in_flight))
wake_up(&ctx->io_wait);
}
static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int page_nr, int rw) __must_hold(local)
static void bm_page_io_async(struct bm_aio_ctx *ctx, 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);
struct drbd_conf *mdev = ctx->mdev;
struct drbd_bitmap *b = mdev->bitmap;
struct page *page;
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 */
* flexible external meta data device,
* or with PAGE_SIZE > 4k */
len = min_t(unsigned int, PAGE_SIZE,
(drbd_md_last_sector(mdev->ldev) - on_disk_sector + 1)<<9);
/* serialize IO on this page */
bm_page_lock_io(mdev, page_nr);
/* before memcpy and submit,
* so it can be redirtied any time */
bm_set_page_unchanged(b->bm_pages[page_nr]);
if (ctx->flags & BM_AIO_COPY_PAGES) {
/* FIXME alloc_page is good enough for now, but actually needs
* to use pre-allocated page pool */
void *src, *dest;
page = alloc_page(__GFP_HIGHMEM|__GFP_WAIT);
dest = kmap_atomic(page, KM_USER0);
src = kmap_atomic(b->bm_pages[page_nr], KM_USER1);
memcpy(dest, src, PAGE_SIZE);
kunmap_atomic(src, KM_USER1);
kunmap_atomic(dest, KM_USER0);
bm_store_page_idx(page, page_nr);
} else
page = b->bm_pages[page_nr];
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_add_page(bio, page, len, 0);
bio->bi_private = ctx;
bio->bi_end_io = bm_async_io_complete;
if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) {
@ -841,36 +993,72 @@ static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int
/*
* 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)
static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_idx) __must_hold(local)
{
struct bm_aio_ctx ctx =
{ .flags = lazy_writeout_upper_idx ? BM_AIO_COPY_PAGES : 0 };
struct drbd_bitmap *b = mdev->bitmap;
/* sector_t sector; */
int bm_words, num_pages, i;
int last_page, i, count = 0;
unsigned long now;
char ppb[10];
int err = 0;
WARN_ON(!bm_is_locked(b));
/*
* We are protected against bitmap disappearing/resizing by holding an
* ldev reference (caller must have called get_ldev()).
* For read/write, we are protected against changes to the bitmap by
* the bitmap lock (see drbd_bitmap_io).
* For lazy writeout, we don't care for ongoing changes to the bitmap,
* as we submit copies of pages anyways.
*/
if (!ctx.flags)
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;
/* 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);
now = jiffies;
atomic_set(&b->bm_async_io, num_pages);
__clear_bit(BM_MD_IO_ERROR, &b->bm_flags);
ctx.mdev = mdev;
atomic_set(&ctx.in_flight, 1); /* one extra ref */
init_waitqueue_head(&ctx.io_wait);
ctx.error = 0;
/* 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);
for (i = 0; i <= last_page; i++) {
/* ignore completely unchanged pages */
if (lazy_writeout_upper_idx && i == lazy_writeout_upper_idx)
break;
if (rw & WRITE) {
if (bm_test_page_unchanged(b->bm_pages[i])) {
dynamic_dev_dbg(DEV, "skipped bm write for idx %u\n", i);
continue;
}
/* during lazy writeout,
* ignore those pages not marked for lazy writeout. */
if (lazy_writeout_upper_idx &&
!bm_test_page_lazy_writeout(b->bm_pages[i])) {
dynamic_dev_dbg(DEV, "skipped bm lazy write for idx %u\n", i);
continue;
}
}
atomic_inc(&ctx.in_flight);
bm_page_io_async(&ctx, i, rw);
++count;
cond_resched();
}
wait_event(b->bm_io_wait, atomic_read(&b->bm_async_io) == 0);
atomic_dec(&ctx.in_flight); /* drop the extra ref */
wait_event(ctx.io_wait, atomic_read(&ctx.in_flight) == 0);
dev_info(DEV, "bitmap %s of %u pages took %lu jiffies\n",
rw == WRITE ? "WRITE" : "READ",
count, jiffies - now);
if (test_bit(BM_MD_IO_ERROR, &b->bm_flags)) {
if (ctx.error) {
dev_alert(DEV, "we had at least one MD IO ERROR during bitmap IO\n");
drbd_chk_io_error(mdev, 1, true);
err = -EIO;
err = -EIO; /* ctx.error ? */
}
now = jiffies;
@ -895,55 +1083,63 @@ static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local)
*/
int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local)
{
return bm_rw(mdev, READ);
return bm_rw(mdev, READ, 0);
}
/**
* drbd_bm_write() - Write the whole bitmap to its on disk location.
* @mdev: DRBD device.
*
* Will only write pages that have changed since last IO.
*/
int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local)
{
return bm_rw(mdev, WRITE);
return bm_rw(mdev, WRITE, 0);
}
/**
* drbd_bm_write_sect: Writes a 512 (MD_SECTOR_SIZE) byte piece of the bitmap
* drbd_bm_lazy_write_out() - Write bitmap pages 0 to @upper_idx-1, if they have changed.
* @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.
* @upper_idx: 0: write all changed pages; +ve: page index to stop scanning for changed pages
*/
int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local)
int drbd_bm_write_lazy(struct drbd_conf *mdev, unsigned upper_idx) __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;
return bm_rw(mdev, WRITE, upper_idx);
}
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);
/**
* drbd_bm_write_page: Writes a PAGE_SIZE aligned piece of bitmap
* @mdev: DRBD device.
* @idx: bitmap page index
*
* We don't want to special case on logical_block_size of the underlaying
* device, so we submit PAGE_SIZE aligned pieces containing the requested enr.
* Note that on "most" systems, PAGE_SIZE is 4k.
*/
int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(local)
{
struct bm_aio_ctx ctx = { .flags = BM_AIO_COPY_PAGES, };
if (bm_test_page_unchanged(mdev->bitmap->bm_pages[idx])) {
dev_info(DEV, "skipped bm page write for idx %u\n", idx);
return 0;
}
ctx.mdev = mdev;
atomic_set(&ctx.in_flight, 1);
init_waitqueue_head(&ctx.io_wait);
bm_page_io_async(&ctx, idx, WRITE_SYNC);
wait_event(ctx.io_wait, atomic_read(&ctx.in_flight) == 0);
if (ctx.error)
drbd_chk_io_error(mdev, 1, true);
/* that should force detach, so the in memory bitmap will be
* gone in a moment as well. */
mdev->bm_writ_cnt++;
mutex_unlock(&mdev->md_io_mutex);
return err;
return ctx.error;
}
/* NOTE
@ -965,10 +1161,9 @@ static unsigned long __bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo,
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);
/* bit offset of the first bit in the page */
bit_offset = bm_fo & ~BPP_MASK;
p_addr = __bm_map_pidx(b, bm_bit_to_page_idx(b, bm_fo), km);
if (find_zero_bit)
i = generic_find_next_zero_le_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK);
@ -1048,8 +1243,9 @@ static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
struct drbd_bitmap *b = mdev->bitmap;
unsigned long *p_addr = NULL;
unsigned long bitnr;
unsigned long last_page_nr = -1UL;
unsigned int last_page_nr = -1U;
int c = 0;
int changed_total = 0;
if (e >= b->bm_bits) {
dev_err(DEV, "ASSERT FAILED: bit_s=%lu bit_e=%lu bm_bits=%lu\n",
@ -1057,12 +1253,17 @@ static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
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);
unsigned int page_nr = bm_bit_to_page_idx(b, bitnr);
if (page_nr != last_page_nr) {
if (p_addr)
__bm_unmap(p_addr, km);
p_addr = __bm_map_paddr(b, offset, km);
if (c < 0)
bm_set_page_lazy_writeout(b->bm_pages[last_page_nr]);
else if (c > 0)
bm_set_page_need_writeout(b->bm_pages[last_page_nr]);
changed_total += c;
c = 0;
p_addr = __bm_map_pidx(b, page_nr, km);
last_page_nr = page_nr;
}
if (val)
@ -1072,8 +1273,13 @@ static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
}
if (p_addr)
__bm_unmap(p_addr, km);
b->bm_set += c;
return c;
if (c < 0)
bm_set_page_lazy_writeout(b->bm_pages[last_page_nr]);
else if (c > 0)
bm_set_page_need_writeout(b->bm_pages[last_page_nr]);
changed_total += c;
b->bm_set += changed_total;
return changed_total;
}
/* returns number of bits actually changed.
@ -1211,8 +1417,7 @@ int drbd_bm_test_bit(struct drbd_conf *mdev, const unsigned long bitnr)
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);
p_addr = bm_map_pidx(b, bm_bit_to_page_idx(b, bitnr));
i = generic_test_le_bit(bitnr & BPP_MASK, p_addr) ? 1 : 0;
bm_unmap(p_addr);
} else if (bitnr == b->bm_bits) {
@ -1231,10 +1436,10 @@ int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsi
{
unsigned long flags;
struct drbd_bitmap *b = mdev->bitmap;
unsigned long *p_addr = NULL, page_nr = -1;
unsigned long *p_addr = NULL;
unsigned long bitnr;
unsigned int page_nr = -1U;
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
@ -1247,12 +1452,12 @@ int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsi
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);
unsigned int idx = bm_bit_to_page_idx(b, bitnr);
if (page_nr != idx) {
page_nr = idx;
if (p_addr)
bm_unmap(p_addr);
p_addr = bm_map_paddr(b, w);
p_addr = bm_map_pidx(b, idx);
}
ERR_IF (bitnr >= b->bm_bits) {
dev_err(DEV, "bitnr=%lu bm_bits=%lu\n", bitnr, b->bm_bits);
@ -1300,7 +1505,7 @@ int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr)
count = 0;
if (s < b->bm_words) {
int n = e-s;
p_addr = bm_map_paddr(b, s);
p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, s));
bm = p_addr + MLPP(s);
while (n--)
count += hweight_long(*bm++);
@ -1335,7 +1540,7 @@ unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, unsigned long al_enr)
count = 0;
if (s < b->bm_words) {
i = do_now = e-s;
p_addr = bm_map_paddr(b, s);
p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, s));
bm = p_addr + MLPP(s);
while (i--) {
count += hweight_long(*bm);

7
drivers/block/drbd/drbd_int.h
View File

@ -833,7 +833,7 @@ enum {
CRASHED_PRIMARY, /* This node was a crashed primary.
* Gets cleared when the state.conn
* goes into C_CONNECTED state. */
WRITE_BM_AFTER_RESYNC, /* A kmalloc() during resync failed */
NO_BARRIER_SUPP, /* underlying block device doesn't implement barriers */
CONSIDER_RESYNC,
MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */
@ -1428,7 +1428,7 @@ extern void _drbd_bm_set_bits(struct drbd_conf *mdev,
const unsigned long s, const unsigned long e);
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_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local);
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 int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local);
extern unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev,
@ -1446,7 +1446,7 @@ extern int drbd_bm_rs_done(struct drbd_conf *mdev);
/* for receive_bitmap */
extern void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset,
size_t number, unsigned long *buffer);
/* for _drbd_send_bitmap and drbd_bm_write_sect */
/* for _drbd_send_bitmap */
extern void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset,
size_t number, unsigned long *buffer);
@ -1641,7 +1641,6 @@ extern int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector,
#define drbd_set_out_of_sync(mdev, sector, size) \
__drbd_set_out_of_sync(mdev, sector, size, __FILE__, __LINE__)
extern void drbd_al_apply_to_bm(struct drbd_conf *mdev);
extern void drbd_al_to_on_disk_bm(struct drbd_conf *mdev);
extern void drbd_al_shrink(struct drbd_conf *mdev);

27
drivers/block/drbd/drbd_main.c
View File

@ -1289,6 +1289,26 @@ static void abw_start_sync(struct drbd_conf *mdev, int rv)
}
}
int drbd_bitmap_io_from_worker(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), char *why)
{
int rv;
D_ASSERT(current == mdev->worker.task);
/* open coded non-blocking drbd_suspend_io(mdev); */
set_bit(SUSPEND_IO, &mdev->flags);
if (!is_susp(mdev->state))
D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0);
drbd_bm_lock(mdev, why);
rv = io_fn(mdev);
drbd_bm_unlock(mdev);
drbd_resume_io(mdev);
return rv;
}
/**
* after_state_ch() - Perform after state change actions that may sleep
* @mdev: DRBD device.
@ -1404,7 +1424,12 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
/* D_DISKLESS Peer becomes secondary */
if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY)
drbd_al_to_on_disk_bm(mdev);
drbd_bitmap_io_from_worker(mdev, &drbd_bm_write, "demote diskless peer");
put_ldev(mdev);
}
if (os.role == R_PRIMARY && ns.role == R_SECONDARY && get_ldev(mdev)) {
drbd_bitmap_io_from_worker(mdev, &drbd_bm_write, "demote");
put_ldev(mdev);
}

11
drivers/block/drbd/drbd_nl.c
View File

@ -407,10 +407,8 @@ drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force)
}
}
if ((new_role == R_SECONDARY) && get_ldev(mdev)) {
drbd_al_to_on_disk_bm(mdev);
put_ldev(mdev);
}
/* writeout of activity log covered areas of the bitmap
* to stable storage done in after state change already */
if (mdev->state.conn >= C_WF_REPORT_PARAMS) {
/* if this was forced, we should consider sync */
@ -1174,7 +1172,10 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
if (cp_discovered) {
drbd_al_apply_to_bm(mdev);
drbd_al_to_on_disk_bm(mdev);
if (drbd_bitmap_io(mdev, &drbd_bm_write, "crashed primary apply AL")) {
retcode = ERR_IO_MD_DISK;
goto force_diskless_dec;
}
}
if (_drbd_bm_total_weight(mdev) == drbd_bm_bits(mdev))

7
drivers/block/drbd/drbd_worker.c
View File

@ -907,10 +907,8 @@ out:
drbd_md_sync(mdev);
if (test_and_clear_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags)) {
dev_info(DEV, "Writing the whole bitmap\n");
drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished");
}
dev_info(DEV, "Writing changed bitmap pages\n");
drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished");
if (khelper_cmd)
drbd_khelper(mdev, khelper_cmd);
@ -1127,7 +1125,6 @@ void drbd_ov_oos_found(struct drbd_conf *mdev, sector_t sector, int size)
mdev->ov_last_oos_size = size>>9;
}
drbd_set_out_of_sync(mdev, sector, size);
set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags);
}
int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel)