- 根目录:
- drivers
- block
- drbd
- drbd_actlog.c
/*
drbd_actlog.c
This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
Copyright (C) 2003-2008, LINBIT Information Technologies GmbH.
Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>.
Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
drbd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
drbd is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with drbd; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/slab.h>
#include <linux/crc32c.h>
#include <linux/drbd.h>
#include <linux/drbd_limits.h>
#include <linux/dynamic_debug.h>
#include "drbd_int.h"
#include "drbd_wrappers.h"
enum al_transaction_types {
AL_TR_UPDATE = 0,
AL_TR_INITIALIZED = 0xffff
};
/* all fields on disc in big endian */
struct __packed al_transaction_on_disk {
/* don't we all like magic */
__be32 magic;
/* to identify the most recent transaction block
* in the on disk ring buffer */
__be32 tr_number;
/* checksum on the full 4k block, with this field set to 0. */
__be32 crc32c;
/* type of transaction, special transaction types like:
* purge-all, set-all-idle, set-all-active, ... to-be-defined
* see also enum al_transaction_types */
__be16 transaction_type;
/* we currently allow only a few thousand extents,
* so 16bit will be enough for the slot number. */
/* how many updates in this transaction */
__be16 n_updates;
/* maximum slot number, "al-extents" in drbd.conf speak.
* Having this in each transaction should make reconfiguration
* of that parameter easier. */
__be16 context_size;
/* slot number the context starts with */
__be16 context_start_slot_nr;
/* Some reserved bytes. Expected usage is a 64bit counter of
* sectors-written since device creation, and other data generation tag
* supporting usage */
__be32 __reserved[4];
/* --- 36 byte used --- */
/* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes
* in one transaction, then use the remaining byte in the 4k block for
* context information. "Flexible" number of updates per transaction
* does not help, as we have to account for the case when all update
* slots are used anyways, so it would only complicate code without
* additional benefit.
*/
__be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION];
/* but the extent number is 32bit, which at an extent size of 4 MiB
* allows to cover device sizes of up to 2**54 Byte (16 PiB) */
__be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION];
/* --- 420 bytes used (36 + 64*6) --- */
/* 4096 - 420 = 3676 = 919 * 4 */
__be32 context[AL_CONTEXT_PER_TRANSACTION];
};
struct update_odbm_work {
struct drbd_work w;
unsigned int enr;
};
struct update_al_work {
struct drbd_work w;
struct completion event;
int err;
};
void *drbd_md_get_buffer(struct drbd_conf *mdev)
{
int r;
wait_event(mdev->misc_wait,
(r = atomic_cmpxchg(&mdev->md_io_in_use, 0, 1)) == 0 ||
mdev->state.disk <= D_FAILED);
return r ? NULL : page_address(mdev->md_io_page);
}
void drbd_md_put_buffer(struct drbd_conf *mdev)
{
if (atomic_dec_and_test(&mdev->md_io_in_use))
wake_up(&mdev->misc_wait);
}
void wait_until_done_or_force_detached(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
unsigned int *done)
{
long dt;
rcu_read_lock();
dt = rcu_dereference(bdev->disk_conf)->disk_timeout;
rcu_read_unlock();
dt = dt * HZ / 10;
if (dt == 0)
dt = MAX_SCHEDULE_TIMEOUT;
dt = wait_event_timeout(mdev->misc_wait,
*done || test_bit(FORCE_DETACH, &mdev->flags), dt);
if (dt == 0) {
dev_err(DEV, "meta-data IO operation timed out\n");
drbd_chk_io_error(mdev, 1, DRBD_FORCE_DETACH);
}
}
static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev,
struct page *page, sector_t sector,
int rw, int size)
{
struct bio *bio;
int err;
mdev->md_io.done = 0;
mdev->md_io.error = -ENODEV;
if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
rw |= REQ_FUA | REQ_FLUSH;
rw |= REQ_SYNC;
bio = bio_alloc_drbd(GFP_NOIO);
bio->bi_bdev = bdev->md_bdev;
bio->bi_sector = sector;
err = -EIO;
if (bio_add_page(bio, page, size, 0) != size)
goto out;
bio->bi_private = &mdev->md_io;
bio->bi_end_io = drbd_md_io_complete;
bio->bi_rw = rw;
if (!(rw & WRITE) && mdev->state.disk == D_DISKLESS && mdev->ldev == NULL)
/* special case, drbd_md_read() during drbd_adm_attach(): no get_ldev */
;
else if (!get_ldev_if_state(mdev, D_ATTACHING)) {
/* Corresponding put_ldev in drbd_md_io_complete() */
dev_err(DEV, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n");
err = -ENODEV;
goto out;
}
bio_get(bio); /* one bio_put() is in the completion handler */
atomic_inc(&mdev->md_io_in_use); /* drbd_md_put_buffer() is in the completion handler */
if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD))
bio_endio(bio, -EIO);
else
submit_bio(rw, bio);
wait_until_done_or_force_detached(mdev, bdev, &mdev->md_io.done);
if (bio_flagged(bio, BIO_UPTODATE))
err = mdev->md_io.error;
out:
bio_put(bio);
return err;
}
int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
sector_t sector, int rw)
{
int err;
struct page *iop = mdev->md_io_page;
D_ASSERT(atomic_read(&mdev->md_io_in_use) == 1);
BUG_ON(!bdev->md_bdev);
dev_dbg(DEV, "meta_data io: %s [%d]:%s(,%llus,%s) %pS\n",
current->comm, current->pid, __func__,
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ",
(void*)_RET_IP_ );
if (sector < drbd_md_first_sector(bdev) ||
sector + 7 > drbd_md_last_sector(bdev))
dev_alert(DEV, "%s [%d]:%s(,%llus,%s) out of range md access!\n",
current->comm, current->pid, __func__,
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
/* we do all our meta data IO in aligned 4k blocks. */
err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, 4096);
if (err) {
dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n",
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ", err);
}
return err;
}
static struct bm_extent *find_active_resync_extent(struct drbd_conf *mdev, unsigned int enr)
{
struct lc_element *tmp;
tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
if (unlikely(tmp != NULL)) {
struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
if (test_bit(BME_NO_WRITES, &bm_ext->flags))
return bm_ext;
}
return NULL;
}
static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr, bool nonblock)
{
struct lc_element *al_ext;
struct bm_extent *bm_ext;
int wake;
spin_lock_irq(&mdev->al_lock);
bm_ext = find_active_resync_extent(mdev, enr);
if (bm_ext) {
wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
spin_unlock_irq(&mdev->al_lock);
if (wake)
wake_up(&mdev->al_wait);
return NULL;
}
if (nonblock)
al_ext = lc_try_get(mdev->act_log, enr);
else
al_ext = lc_get(mdev->act_log, enr);
spin_unlock_irq(&mdev->al_lock);
return al_ext;
}
bool drbd_al_begin_io_fastpath(struct drbd_conf *mdev, struct drbd_interval *i)
{
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
D_ASSERT((unsigned)(last - first) <= 1);
D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
/* FIXME figure out a fast path for bios crossing AL extent boundaries */
if (first != last)
return false;
return _al_get(mdev, first, true);
}
bool drbd_al_begin_io_prepare(struct drbd_conf *mdev, struct drbd_interval *i)
{
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
unsigned enr;
bool need_transaction = false;
D_ASSERT(first <= last);
D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
for (enr = first; enr <= last; enr++) {
struct lc_element *al_ext;
wait_event(mdev->al_wait,
(al_ext = _al_get(mdev, enr, false)) != NULL);
if (al_ext->lc_number != enr)
need_transaction = true;
}
return need_transaction;
}
static int al_write_transaction(struct drbd_conf *mdev, bool delegate);
/* When called through generic_make_request(), we must delegate
* activity log I/O to the worker thread: a further request
* submitted via generic_make_request() within the same task
* would be queued on current->bio_list, and would only start
* after this function returns (see generic_make_request()).
*
* However, if we *are* the worker, we must not delegate to ourselves.
*/
/*
* @delegate: delegate activity log I/O to the worker thread
*/
void drbd_al_begin_io_commit(struct drbd_conf *mdev, bool delegate)
{
bool locked = false;
BUG_ON(delegate && current == mdev->tconn->worker.task);
/* Serialize multiple transactions.
* This uses test_and_set_bit, memory barrier is implicit.
*/
wait_event(mdev->al_wait,
mdev->act_log->pending_changes == 0 ||
(locked = lc_try_lock_for_transaction(mdev->act_log)));
if (locked) {
/* Double check: it may have been committed by someone else,
* while we have been waiting for the lock. */
if (mdev->act_log->pending_changes) {
bool write_al_updates;
rcu_read_lock();
write_al_updates = rcu_dereference(mdev->ldev->disk_conf)->al_updates;
rcu_read_unlock();
if (write_al_updates)
al_write_transaction(mdev, delegate);
spin_lock_irq(&mdev->al_lock);
/* FIXME
if (err)
we need an "lc_cancel" here;
*/
lc_committed(mdev->act_log);
spin_unlock_irq(&mdev->al_lock);
}
lc_unlock(mdev->act_log);
wake_up(&mdev->al_wait);
}
}
/*
* @delegate: delegate activity log I/O to the worker thread
*/
void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i, bool delegate)
{
BUG_ON(delegate && current == mdev->tconn->worker.task);
if (drbd_al_begin_io_prepare(mdev, i))
drbd_al_begin_io_commit(mdev, delegate);
}
int drbd_al_begin_io_nonblock(struct drbd_conf *mdev, struct drbd_interval *i)
{
struct lru_cache *al = mdev->act_log;
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
unsigned nr_al_extents;
unsigned available_update_slots;
unsigned enr;
D_ASSERT(first <= last);
nr_al_extents = 1 + last - first; /* worst case: all touched extends are cold. */
available_update_slots = min(al->nr_elements - al->used,
al->max_pending_changes - al->pending_changes);
/* We want all necessary updates for a given request within the same transaction
* We could first check how many updates are *actually* needed,
* and use that instead of the worst-case nr_al_extents */
if (available_update_slots < nr_al_extents)
return -EWOULDBLOCK;
/* Is resync active in this area? */
for (enr = first; enr <= last; enr++) {
struct lc_element *tmp;
tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
if (unlikely(tmp != NULL)) {
struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
if (!test_and_set_bit(BME_PRIORITY, &bm_ext->flags))
return -EBUSY;
return -EWOULDBLOCK;
}
}
}
/* Checkout the refcounts.
* Given that we checked for available elements and update slots above,
* this has to be successful. */
for (enr = first; enr <= last; enr++) {
struct lc_element *al_ext;
al_ext = lc_get_cumulative(mdev->act_log, enr);
if (!al_ext)
dev_info(DEV, "LOGIC BUG for enr=%u\n", enr);
}
return 0;
}
void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i)
{
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
unsigned enr;
struct lc_element *extent;
unsigned long flags;
D_ASSERT(first <= last);
spin_lock_irqsave(&mdev->al_lock, flags);
for (enr = first; enr <= last; enr++) {
extent = lc_find(mdev->act_log, enr);
if (!extent) {
dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr);
continue;
}
lc_put(mdev->act_log, extent);
}
spin_unlock_irqrestore(&mdev->al_lock, flags);
wake_up(&mdev->al_wait);
}
#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) -
/* resync extent number to bit */
(BM_EXT_SHIFT - BM_BLOCK_SHIFT));
}
static sector_t al_tr_number_to_on_disk_sector(struct drbd_conf *mdev)
{
const unsigned int stripes = mdev->ldev->md.al_stripes;
const unsigned int stripe_size_4kB = mdev->ldev->md.al_stripe_size_4k;
/* transaction number, modulo on-disk ring buffer wrap around */
unsigned int t = mdev->al_tr_number % (mdev->ldev->md.al_size_4k);
/* ... to aligned 4k on disk block */
t = ((t % stripes) * stripe_size_4kB) + t/stripes;
/* ... to 512 byte sector in activity log */
t *= 8;
/* ... plus offset to the on disk position */
return mdev->ldev->md.md_offset + mdev->ldev->md.al_offset + t;
}
static int
_al_write_transaction(struct drbd_conf *mdev)
{
struct al_transaction_on_disk *buffer;
struct lc_element *e;
sector_t sector;
int i, mx;
unsigned extent_nr;
unsigned crc = 0;
int err = 0;
if (!get_ldev(mdev)) {
dev_err(DEV, "disk is %s, cannot start al transaction\n",
drbd_disk_str(mdev->state.disk));
return -EIO;
}
/* The bitmap write may have failed, causing a state change. */
if (mdev->state.disk < D_INCONSISTENT) {
dev_err(DEV,
"disk is %s, cannot write al transaction\n",
drbd_disk_str(mdev->state.disk));
put_ldev(mdev);
return -EIO;
}
buffer = drbd_md_get_buffer(mdev); /* protects md_io_buffer, al_tr_cycle, ... */
if (!buffer) {
dev_err(DEV, "disk failed while waiting for md_io buffer\n");
put_ldev(mdev);
return -ENODEV;
}
memset(buffer, 0, sizeof(*buffer));
buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);
buffer->tr_number = cpu_to_be32(mdev->al_tr_number);
i = 0;
/* Even though no one can start to change this list
* once we set the LC_LOCKED -- from drbd_al_begin_io(),
* lc_try_lock_for_transaction() --, someone may still
* be in the process of changing it. */
spin_lock_irq(&mdev->al_lock);
list_for_each_entry(e, &mdev->act_log->to_be_changed, list) {
if (i == AL_UPDATES_PER_TRANSACTION) {
i++;
break;
}
buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index);
buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number);
if (e->lc_number != LC_FREE)
drbd_bm_mark_for_writeout(mdev,
al_extent_to_bm_page(e->lc_number));
i++;
}
spin_unlock_irq(&mdev->al_lock);
BUG_ON(i > AL_UPDATES_PER_TRANSACTION);
buffer->n_updates = cpu_to_be16(i);
for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) {
buffer->update_slot_nr[i] = cpu_to_be16(-1);
buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE);
}
buffer->context_size = cpu_to_be16(mdev->act_log->nr_elements);
buffer->context_start_slot_nr = cpu_to_be16(mdev->al_tr_cycle);
mx = min_t(int, AL_CONTEXT_PER_TRANSACTION,
mdev->act_log->nr_elements - mdev->al_tr_cycle);
for (i = 0; i < mx; i++) {
unsigned idx = mdev->al_tr_cycle + i;
extent_nr = lc_element_by_index(mdev->act_log, idx)->lc_number;
buffer->context[i] = cpu_to_be32(extent_nr);
}
for (; i < AL_CONTEXT_PER_TRANSACTION; i++)
buffer->context[i] = cpu_to_be32(LC_FREE);
mdev->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION;
if (mdev->al_tr_cycle >= mdev->act_log->nr_elements)
mdev->al_tr_cycle = 0;
sector = al_tr_number_to_on_disk_sector(mdev);
crc = crc32c(0, buffer, 4096);
buffer->crc32c = cpu_to_be32(crc);
if (drbd_bm_write_hinted(mdev))
err = -EIO;
else {
bool write_al_updates;
rcu_read_lock();
write_al_updates = rcu_dereference(mdev->ldev->disk_conf)->al_updates;
rcu_read_unlock();
if (write_al_updates) {
if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
err = -EIO;
drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
} else {
mdev->al_tr_number++;
mdev->al_writ_cnt++;
}
}
}
drbd_md_put_buffer(mdev);
put_ldev(mdev);
return err;
}
static int w_al_write_transaction(struct drbd_work *w, int unused)
{
struct update_al_work *aw = container_of(w, struct update_al_work, w);
struct drbd_conf *mdev = w->mdev;
int err;
err = _al_write_transaction(mdev);
aw->err = err;
complete(&aw->event);
return err != -EIO ? err : 0;
}
/* Calls from worker context (see w_restart_disk_io()) need to write the
transaction directly. Others came through generic_make_request(),
those need to delegate it to the worker. */
static int al_write_transaction(struct drbd_conf *mdev, bool delegate)
{
if (delegate) {
struct update_al_work al_work;
init_completion(&al_work.event);
al_work.w.cb = w_al_write_transaction;
al_work.w.mdev = mdev;
drbd_queue_work_front(&mdev->tconn->sender_work, &al_work.w);
wait_for_completion(&al_work.event);
return al_work.err;
} else
return _al_write_transaction(mdev);
}
static int _try_lc_del(struct drbd_conf *mdev, struct lc_element *al_ext)
{
int rv;
spin_lock_irq(&mdev->al_lock);
rv = (al_ext->refcnt == 0);
if (likely(rv))
lc_del(mdev->act_log, al_ext);
spin_unlock_irq(&mdev->al_lock);
return rv;
}
/**
* drbd_al_shrink() - Removes all active extents form the activity log
* @mdev: DRBD device.
*
* Removes all active extents form the activity log, waiting until
* the reference count of each entry dropped to 0 first, of course.
*
* You need to lock mdev->act_log with lc_try_lock() / lc_unlock()
*/
void drbd_al_shrink(struct drbd_conf *mdev)
{
struct lc_element *al_ext;
int i;
D_ASSERT(test_bit(__LC_LOCKED, &mdev->act_log->flags));
for (i = 0; i < mdev->act_log->nr_elements; i++) {
al_ext = lc_element_by_index(mdev->act_log, i);
if (al_ext->lc_number == LC_FREE)
continue;
wait_event(mdev->al_wait, _try_lc_del(mdev, al_ext));
}
wake_up(&mdev->al_wait);
}
static int w_update_odbm(struct drbd_work *w, int unused)
{
struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w);
struct drbd_conf *mdev = w->mdev;
struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, };
if (!get_ldev(mdev)) {
if (__ratelimit(&drbd_ratelimit_state))
dev_warn(DEV, "Can not update on disk bitmap, local IO disabled.\n");
kfree(udw);
return 0;
}
drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr));
put_ldev(mdev);
kfree(udw);
if (drbd_bm_total_weight(mdev) <= mdev->rs_failed) {
switch (mdev->state.conn) {
case C_SYNC_SOURCE: case C_SYNC_TARGET:
case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T:
drbd_resync_finished(mdev);
default:
/* nothing to do */
break;
}
}
drbd_bcast_event(mdev, &sib);
return 0;
}
/* ATTENTION. The AL's extents are 4MB each, while the extents in the
* resync LRU-cache are 16MB each.
* The caller of this function has to hold an get_ldev() reference.
*
* TODO will be obsoleted once we have a caching lru of the on disk bitmap
*/
static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector,
int count, int success)
{
struct lc_element *e;
struct update_odbm_work *udw;
unsigned int enr;
D_ASSERT(atomic_read(&mdev->local_cnt));
/* I simply assume that a sector/size pair never crosses
* a 16 MB extent border. (Currently this is true...) */
enr = BM_SECT_TO_EXT(sector);
e = lc_get(mdev->resync, enr);
if (e) {
struct bm_extent *ext = lc_entry(e, struct bm_extent, lce);
if (ext->lce.lc_number == enr) {
if (success)
ext->rs_left -= count;
else
ext->rs_failed += count;
if (ext->rs_left < ext->rs_failed) {
dev_warn(DEV, "BAD! sector=%llus enr=%u rs_left=%d "
"rs_failed=%d count=%d cstate=%s\n",
(unsigned long long)sector,
ext->lce.lc_number, ext->rs_left,
ext->rs_failed, count,
drbd_conn_str(mdev->state.conn));
/* We don't expect to be able to clear more bits
* than have been set when we originally counted
* the set bits to cache that value in ext->rs_left.
* Whatever the reason (disconnect during resync,
* delayed local completion of an application write),
* try to fix it up by recounting here. */
ext->rs_left = drbd_bm_e_weight(mdev, enr);
}
} else {
/* Normally this element should be in the cache,
* since drbd_rs_begin_io() pulled it already in.
*
* But maybe an application write finished, and we set
* something outside the resync lru_cache in sync.
*/
int rs_left = drbd_bm_e_weight(mdev, enr);
if (ext->flags != 0) {
dev_warn(DEV, "changing resync lce: %d[%u;%02lx]"
" -> %d[%u;00]\n",
ext->lce.lc_number, ext->rs_left,
ext->flags, enr, rs_left);
ext->flags = 0;
}
if (ext->rs_failed) {
dev_warn(DEV, "Kicking resync_lru element enr=%u "
"out with rs_failed=%d\n",
ext->lce.lc_number, ext->rs_failed);
}
ext->rs_left = rs_left;
ext->rs_failed = success ? 0 : count;
/* we don't keep a persistent log of the resync lru,
* we can commit any change right away. */
lc_committed(mdev->resync);
}
lc_put(mdev->resync, &ext->lce);
/* no race, we are within the al_lock! */
if (ext->rs_left == ext->rs_failed) {
ext->rs_failed = 0;
udw = kmalloc(sizeof(*udw), GFP_ATOMIC);
if (udw) {
udw->enr = ext->lce.lc_number;
udw->w.cb = w_update_odbm;
udw->w.mdev = mdev;
drbd_queue_work_front(&mdev->tconn->sender_work, &udw->w);
} else {
dev_warn(DEV, "Could not kmalloc an udw\n");
}
}
} else {
dev_err(DEV, "lc_get() failed! locked=%d/%d flags=%lu\n",
mdev->resync_locked,
mdev->resync->nr_elements,
mdev->resync->flags);
}
}
void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go)
{
unsigned long now = jiffies;
unsigned long last = mdev->rs_mark_time[mdev->rs_last_mark];
int next = (mdev->rs_last_mark + 1) % DRBD_SYNC_MARKS;
if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) {
if (mdev->rs_mark_left[mdev->rs_last_mark] != still_to_go &&
mdev->state.conn != C_PAUSED_SYNC_T &&
mdev->state.conn != C_PAUSED_SYNC_S) {
mdev->rs_mark_time[next] = now;
mdev->rs_mark_left[next] = still_to_go;
mdev->rs_last_mark = next;
}
}
}
/* clear the bit corresponding to the piece of storage in question:
* size byte of data starting from sector. Only clear a bits of the affected
* one ore more _aligned_ BM_BLOCK_SIZE blocks.
*
* called by worker on C_SYNC_TARGET and receiver on SyncSource.
*
*/
void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size,
const char *file, const unsigned int line)
{
/* Is called from worker and receiver context _only_ */
unsigned long sbnr, ebnr, lbnr;
unsigned long count = 0;
sector_t esector, nr_sectors;
int wake_up = 0;
unsigned long flags;
if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
dev_err(DEV, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n",
(unsigned long long)sector, size);
return;
}
if (!get_ldev(mdev))
return; /* no disk, no metadata, no bitmap to clear bits in */
nr_sectors = drbd_get_capacity(mdev->this_bdev);
esector = sector + (size >> 9) - 1;
if (!expect(sector < nr_sectors))
goto out;
if (!expect(esector < nr_sectors))
esector = nr_sectors - 1;
lbnr = BM_SECT_TO_BIT(nr_sectors-1);
/* we clear it (in sync).
* round up start sector, round down end sector. we make sure we only
* clear full, aligned, BM_BLOCK_SIZE (4K) blocks */
if (unlikely(esector < BM_SECT_PER_BIT-1))
goto out;
if (unlikely(esector == (nr_sectors-1)))
ebnr = lbnr;
else
ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
if (sbnr > ebnr)
goto out;
/*
* ok, (capacity & 7) != 0 sometimes, but who cares...
* we count rs_{total,left} in bits, not sectors.
*/
count = drbd_bm_clear_bits(mdev, sbnr, ebnr);
if (count) {
drbd_advance_rs_marks(mdev, drbd_bm_total_weight(mdev));
spin_lock_irqsave(&mdev->al_lock, flags);
drbd_try_clear_on_disk_bm(mdev, sector, count, true);
spin_unlock_irqrestore(&mdev->al_lock, flags);
/* just wake_up unconditional now, various lc_chaged(),
* lc_put() in drbd_try_clear_on_disk_bm(). */
wake_up = 1;
}
out:
put_ldev(mdev);
if (wake_up)
wake_up(&mdev->al_wait);
}
/*
* this is intended to set one request worth of data out of sync.
* affects at least 1 bit,
* and at most 1+DRBD_MAX_BIO_SIZE/BM_BLOCK_SIZE bits.
*
* called by tl_clear and drbd_send_dblock (==drbd_make_request).
* so this can be _any_ process.
*/
int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
const char *file, const unsigned int line)
{
unsigned long sbnr, ebnr, flags;
sector_t esector, nr_sectors;
unsigned int enr, count = 0;
struct lc_element *e;
/* this should be an empty REQ_FLUSH */
if (size == 0)
return 0;
if (size < 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
dev_err(DEV, "sector: %llus, size: %d\n",
(unsigned long long)sector, size);
return 0;
}
if (!get_ldev(mdev))
return 0; /* no disk, no metadata, no bitmap to set bits in */
nr_sectors = drbd_get_capacity(mdev->this_bdev);
esector = sector + (size >> 9) - 1;
if (!expect(sector < nr_sectors))
goto out;
if (!expect(esector < nr_sectors))
esector = nr_sectors - 1;
/* we set it out of sync,
* we do not need to round anything here */
sbnr = BM_SECT_TO_BIT(sector);
ebnr = BM_SECT_TO_BIT(esector);
/* ok, (capacity & 7) != 0 sometimes, but who cares...
* we count rs_{total,left} in bits, not sectors. */
spin_lock_irqsave(&mdev->al_lock, flags);
count = drbd_bm_set_bits(mdev, sbnr, ebnr);
enr = BM_SECT_TO_EXT(sector);
e = lc_find(mdev->resync, enr);
if (e)
lc_entry(e, struct bm_extent, lce)->rs_left += count;
spin_unlock_irqrestore(&mdev->al_lock, flags);
out:
put_ldev(mdev);
return count;
}
static
struct bm_extent *_bme_get(struct drbd_conf *mdev, unsigned int enr)
{
struct lc_element *e;
struct bm_extent *bm_ext;
int wakeup = 0;
unsigned long rs_flags;
spin_lock_irq(&mdev->al_lock);
if (mdev->resync_locked > mdev->resync->nr_elements/2) {
spin_unlock_irq(&mdev->al_lock);
return NULL;
}
e = lc_get(mdev->resync, enr);
bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
if (bm_ext) {
if (bm_ext->lce.lc_number != enr) {
bm_ext->rs_left = drbd_bm_e_weight(mdev, enr);
bm_ext->rs_failed = 0;
lc_committed(mdev->resync);
wakeup = 1;
}
if (bm_ext->lce.refcnt == 1)
mdev->resync_locked++;
set_bit(BME_NO_WRITES, &bm_ext->flags);
}
rs_flags = mdev->resync->flags;
spin_unlock_irq(&mdev->al_lock);
if (wakeup)
wake_up(&mdev->al_wait);
if (!bm_ext) {
if (rs_flags & LC_STARVING)
dev_warn(DEV, "Have to wait for element"
" (resync LRU too small?)\n");
BUG_ON(rs_flags & LC_LOCKED);
}
return bm_ext;
}
static int _is_in_al(struct drbd_conf *mdev, unsigned int enr)
{
int rv;
spin_lock_irq(&mdev->al_lock);
rv = lc_is_used(mdev->act_log, enr);
spin_unlock_irq(&mdev->al_lock);
return rv;
}
/**
* drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED
* @mdev: DRBD device.
* @sector: The sector number.
*
* This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted.
*/
int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector)
{
unsigned int enr = BM_SECT_TO_EXT(sector);
struct bm_extent *bm_ext;
int i, sig;
int sa = 200; /* Step aside 200 times, then grab the extent and let app-IO wait.
200 times -> 20 seconds. */
retry:
sig = wait_event_interruptible(mdev->al_wait,
(bm_ext = _bme_get(mdev, enr)));
if (sig)
return -EINTR;
if (test_bit(BME_LOCKED, &bm_ext->flags))
return 0;
for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
sig = wait_event_interruptible(mdev->al_wait,
!_is_in_al(mdev, enr * AL_EXT_PER_BM_SECT + i) ||
test_bit(BME_PRIORITY, &bm_ext->flags));
if (sig || (test_bit(BME_PRIORITY, &bm_ext->flags) && sa)) {
spin_lock_irq(&mdev->al_lock);
if (lc_put(mdev->resync, &bm_ext->lce) == 0) {
bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */
mdev->resync_locked--;
wake_up(&mdev->al_wait);
}
spin_unlock_irq(&mdev->al_lock);
if (sig)
return -EINTR;
if (schedule_timeout_interruptible(HZ/10))
return -EINTR;
if (sa && --sa == 0)
dev_warn(DEV,"drbd_rs_begin_io() stepped aside for 20sec."
"Resync stalled?\n");
goto retry;
}
}
set_bit(BME_LOCKED, &bm_ext->flags);
return 0;
}
/**
* drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep
* @mdev: DRBD device.
* @sector: The sector number.
*
* Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then
* tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN
* if there is still application IO going on in this area.
*/
int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector)
{
unsigned int enr = BM_SECT_TO_EXT(sector);
const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT;
struct lc_element *e;
struct bm_extent *bm_ext;
int i;
spin_lock_irq(&mdev->al_lock);
if (mdev->resync_wenr != LC_FREE && mdev->resync_wenr != enr) {
/* in case you have very heavy scattered io, it may
* stall the syncer undefined if we give up the ref count
* when we try again and requeue.
*
* if we don't give up the refcount, but the next time
* we are scheduled this extent has been "synced" by new
* application writes, we'd miss the lc_put on the
* extent we keep the refcount on.
* so we remembered which extent we had to try again, and
* if the next requested one is something else, we do
* the lc_put here...
* we also have to wake_up
*/
e = lc_find(mdev->resync, mdev->resync_wenr);
bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
if (bm_ext) {
D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags));
clear_bit(BME_NO_WRITES, &bm_ext->flags);
mdev->resync_wenr = LC_FREE;
if (lc_put(mdev->resync, &bm_ext->lce) == 0)
mdev->resync_locked--;
wake_up(&mdev->al_wait);
} else {
dev_alert(DEV, "LOGIC BUG\n");
}
}
/* TRY. */
e = lc_try_get(mdev->resync, enr);
bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
if (bm_ext) {
if (test_bit(BME_LOCKED, &bm_ext->flags))
goto proceed;
if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) {
mdev->resync_locked++;
} else {
/* we did set the BME_NO_WRITES,
* but then could not set BME_LOCKED,
* so we tried again.
* drop the extra reference. */
bm_ext->lce.refcnt--;
D_ASSERT(bm_ext->lce.refcnt > 0);
}
goto check_al;
} else {
/* do we rather want to try later? */
if (mdev->resync_locked > mdev->resync->nr_elements-3)
goto try_again;
/* Do or do not. There is no try. -- Yoda */
e = lc_get(mdev->resync, enr);
bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
if (!bm_ext) {
const unsigned long rs_flags = mdev->resync->flags;
if (rs_flags & LC_STARVING)
dev_warn(DEV, "Have to wait for element"
" (resync LRU too small?)\n");
BUG_ON(rs_flags & LC_LOCKED);
goto try_again;
}
if (bm_ext->lce.lc_number != enr) {
bm_ext->rs_left = drbd_bm_e_weight(mdev, enr);
bm_ext->rs_failed = 0;
lc_committed(mdev->resync);
wake_up(&mdev->al_wait);
D_ASSERT(test_bit(BME_LOCKED, &bm_ext->flags) == 0);
}
set_bit(BME_NO_WRITES, &bm_ext->flags);
D_ASSERT(bm_ext->lce.refcnt == 1);
mdev->resync_locked++;
goto check_al;
}
check_al:
for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
if (lc_is_used(mdev->act_log, al_enr+i))
goto try_again;
}
set_bit(BME_LOCKED, &bm_ext->flags);
proceed:
mdev->resync_wenr = LC_FREE;
spin_unlock_irq(&mdev->al_lock);
return 0;
try_again:
if (bm_ext)
mdev->resync_wenr = enr;
spin_unlock_irq(&mdev->al_lock);
return -EAGAIN;
}
void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector)
{
unsigned int enr = BM_SECT_TO_EXT(sector);
struct lc_element *e;
struct bm_extent *bm_ext;
unsigned long flags;
spin_lock_irqsave(&mdev->al_lock, flags);
e = lc_find(mdev->resync, enr);
bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
if (!bm_ext) {
spin_unlock_irqrestore(&mdev->al_lock, flags);
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "drbd_rs_complete_io() called, but extent not found\n");
return;
}
if (bm_ext->lce.refcnt == 0) {
spin_unlock_irqrestore(&mdev->al_lock, flags);
dev_err(DEV, "drbd_rs_complete_io(,%llu [=%u]) called, "
"but refcnt is 0!?\n",
(unsigned long long)sector, enr);
return;
}
if (lc_put(mdev->resync, &bm_ext->lce) == 0) {
bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */
mdev->resync_locked--;
wake_up(&mdev->al_wait);
}
spin_unlock_irqrestore(&mdev->al_lock, flags);
}
/**
* drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED)
* @mdev: DRBD device.
*/
void drbd_rs_cancel_all(struct drbd_conf *mdev)
{
spin_lock_irq(&mdev->al_lock);
if (get_ldev_if_state(mdev, D_FAILED)) { /* Makes sure ->resync is there. */
lc_reset(mdev->resync);
put_ldev(mdev);
}
mdev->resync_locked = 0;
mdev->resync_wenr = LC_FREE;
spin_unlock_irq(&mdev->al_lock);
wake_up(&mdev->al_wait);
}
/**
* drbd_rs_del_all() - Gracefully remove all extents from the resync LRU
* @mdev: DRBD device.
*
* Returns 0 upon success, -EAGAIN if at least one reference count was
* not zero.
*/
int drbd_rs_del_all(struct drbd_conf *mdev)
{
struct lc_element *e;
struct bm_extent *bm_ext;
int i;
spin_lock_irq(&mdev->al_lock);
if (get_ldev_if_state(mdev, D_FAILED)) {
/* ok, ->resync is there. */
for (i = 0; i < mdev->resync->nr_elements; i++) {
e = lc_element_by_index(mdev->resync, i);
bm_ext = lc_entry(e, struct bm_extent, lce);
if (bm_ext->lce.lc_number == LC_FREE)
continue;
if (bm_ext->lce.lc_number == mdev->resync_wenr) {
dev_info(DEV, "dropping %u in drbd_rs_del_all, apparently"
" got 'synced' by application io\n",
mdev->resync_wenr);
D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags));
clear_bit(BME_NO_WRITES, &bm_ext->flags);
mdev->resync_wenr = LC_FREE;
lc_put(mdev->resync, &bm_ext->lce);
}
if (bm_ext->lce.refcnt != 0) {
dev_info(DEV, "Retrying drbd_rs_del_all() later. "
"refcnt=%d\n", bm_ext->lce.refcnt);
put_ldev(mdev);
spin_unlock_irq(&mdev->al_lock);
return -EAGAIN;
}
D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
D_ASSERT(!test_bit(BME_NO_WRITES, &bm_ext->flags));
lc_del(mdev->resync, &bm_ext->lce);
}
D_ASSERT(mdev->resync->used == 0);
put_ldev(mdev);
}
spin_unlock_irq(&mdev->al_lock);
wake_up(&mdev->al_wait);
return 0;
}
/**
* drbd_rs_failed_io() - Record information on a failure to resync the specified blocks
* @mdev: DRBD device.
* @sector: The sector number.
* @size: Size of failed IO operation, in byte.
*/
void drbd_rs_failed_io(struct drbd_conf *mdev, sector_t sector, int size)
{
/* Is called from worker and receiver context _only_ */
unsigned long sbnr, ebnr, lbnr;
unsigned long count;
sector_t esector, nr_sectors;
int wake_up = 0;
if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
dev_err(DEV, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n",
(unsigned long long)sector, size);
return;
}
nr_sectors = drbd_get_capacity(mdev->this_bdev);
esector = sector + (size >> 9) - 1;
if (!expect(sector < nr_sectors))
return;
if (!expect(esector < nr_sectors))
esector = nr_sectors - 1;
lbnr = BM_SECT_TO_BIT(nr_sectors-1);
/*
* round up start sector, round down end sector. we make sure we only
* handle full, aligned, BM_BLOCK_SIZE (4K) blocks */
if (unlikely(esector < BM_SECT_PER_BIT-1))
return;
if (unlikely(esector == (nr_sectors-1)))
ebnr = lbnr;
else
ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
if (sbnr > ebnr)
return;
/*
* ok, (capacity & 7) != 0 sometimes, but who cares...
* we count rs_{total,left} in bits, not sectors.
*/
spin_lock_irq(&mdev->al_lock);
count = drbd_bm_count_bits(mdev, sbnr, ebnr);
if (count) {
mdev->rs_failed += count;
if (get_ldev(mdev)) {
drbd_try_clear_on_disk_bm(mdev, sector, count, false);
put_ldev(mdev);
}
/* just wake_up unconditional now, various lc_chaged(),
* lc_put() in drbd_try_clear_on_disk_bm(). */
wake_up = 1;
}
spin_unlock_irq(&mdev->al_lock);
if (wake_up)
wake_up(&mdev->al_wait);
}