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linux/drivers/block/drbd/drbd_worker.c
Philipp Reisner d0c3f60f36 drbd: Make sure we do not send state updates during an empty resync [Bugz 271] 
This is a race condition that existed for ages.
The previous commit reduces the window, this one closes it.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-03-11 16:10:40 +01:00

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/*
drbd_worker.c
This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
Copyright (C) 2002-2008, 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/module.h>
#include <linux/drbd.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <linux/mm_inline.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/scatterlist.h>
#include "drbd_int.h"
#include "drbd_req.h"
#define SLEEP_TIME (HZ/10)
static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel);
/* defined here:
drbd_md_io_complete
drbd_endio_write_sec
drbd_endio_read_sec
drbd_endio_pri
* more endio handlers:
atodb_endio in drbd_actlog.c
drbd_bm_async_io_complete in drbd_bitmap.c
* For all these callbacks, note the following:
* The callbacks will be called in irq context by the IDE drivers,
* and in Softirqs/Tasklets/BH context by the SCSI drivers.
* Try to get the locking right :)
*
*/
/* About the global_state_lock
Each state transition on an device holds a read lock. In case we have
to evaluate the sync after dependencies, we grab a write lock, because
we need stable states on all devices for that. */
rwlock_t global_state_lock;
/* used for synchronous meta data and bitmap IO
* submitted by drbd_md_sync_page_io()
*/
void drbd_md_io_complete(struct bio *bio, int error)
{
struct drbd_md_io *md_io;
md_io = (struct drbd_md_io *)bio->bi_private;
md_io->error = error;
complete(&md_io->event);
}
/* reads on behalf of the partner,
* "submitted" by the receiver
*/
void drbd_endio_read_sec(struct bio *bio, int error) __releases(local)
{
unsigned long flags = 0;
struct drbd_epoch_entry *e = NULL;
struct drbd_conf *mdev;
int uptodate = bio_flagged(bio, BIO_UPTODATE);
e = bio->bi_private;
mdev = e->mdev;
if (error)
dev_warn(DEV, "read: error=%d s=%llus\n", error,
(unsigned long long)e->sector);
if (!error && !uptodate) {
dev_warn(DEV, "read: setting error to -EIO s=%llus\n",
(unsigned long long)e->sector);
/* strange behavior of some lower level drivers...
* fail the request by clearing the uptodate flag,
* but do not return any error?! */
error = -EIO;
}
D_ASSERT(e->block_id != ID_VACANT);
spin_lock_irqsave(&mdev->req_lock, flags);
mdev->read_cnt += e->size >> 9;
list_del(&e->w.list);
if (list_empty(&mdev->read_ee))
wake_up(&mdev->ee_wait);
spin_unlock_irqrestore(&mdev->req_lock, flags);
drbd_chk_io_error(mdev, error, FALSE);
drbd_queue_work(&mdev->data.work, &e->w);
put_ldev(mdev);
}
/* writes on behalf of the partner, or resync writes,
* "submitted" by the receiver.
*/
void drbd_endio_write_sec(struct bio *bio, int error) __releases(local)
{
unsigned long flags = 0;
struct drbd_epoch_entry *e = NULL;
struct drbd_conf *mdev;
sector_t e_sector;
int do_wake;
int is_syncer_req;
int do_al_complete_io;
int uptodate = bio_flagged(bio, BIO_UPTODATE);
int is_barrier = bio_rw_flagged(bio, BIO_RW_BARRIER);
e = bio->bi_private;
mdev = e->mdev;
if (error)
dev_warn(DEV, "write: error=%d s=%llus\n", error,
(unsigned long long)e->sector);
if (!error && !uptodate) {
dev_warn(DEV, "write: setting error to -EIO s=%llus\n",
(unsigned long long)e->sector);
/* strange behavior of some lower level drivers...
* fail the request by clearing the uptodate flag,
* but do not return any error?! */
error = -EIO;
}
/* error == -ENOTSUPP would be a better test,
* alas it is not reliable */
if (error && is_barrier && e->flags & EE_IS_BARRIER) {
drbd_bump_write_ordering(mdev, WO_bdev_flush);
spin_lock_irqsave(&mdev->req_lock, flags);
list_del(&e->w.list);
e->w.cb = w_e_reissue;
/* put_ldev actually happens below, once we come here again. */
__release(local);
spin_unlock_irqrestore(&mdev->req_lock, flags);
drbd_queue_work(&mdev->data.work, &e->w);
return;
}
D_ASSERT(e->block_id != ID_VACANT);
spin_lock_irqsave(&mdev->req_lock, flags);
mdev->writ_cnt += e->size >> 9;
is_syncer_req = is_syncer_block_id(e->block_id);
/* after we moved e to done_ee,
* we may no longer access it,
* it may be freed/reused already!
* (as soon as we release the req_lock) */
e_sector = e->sector;
do_al_complete_io = e->flags & EE_CALL_AL_COMPLETE_IO;
list_del(&e->w.list); /* has been on active_ee or sync_ee */
list_add_tail(&e->w.list, &mdev->done_ee);
/* No hlist_del_init(&e->colision) here, we did not send the Ack yet,
* neither did we wake possibly waiting conflicting requests.
* done from "drbd_process_done_ee" within the appropriate w.cb
* (e_end_block/e_end_resync_block) or from _drbd_clear_done_ee */
do_wake = is_syncer_req
? list_empty(&mdev->sync_ee)
: list_empty(&mdev->active_ee);
if (error)
__drbd_chk_io_error(mdev, FALSE);
spin_unlock_irqrestore(&mdev->req_lock, flags);
if (is_syncer_req)
drbd_rs_complete_io(mdev, e_sector);
if (do_wake)
wake_up(&mdev->ee_wait);
if (do_al_complete_io)
drbd_al_complete_io(mdev, e_sector);
wake_asender(mdev);
put_ldev(mdev);
}
/* read, readA or write requests on R_PRIMARY coming from drbd_make_request
*/
void drbd_endio_pri(struct bio *bio, int error)
{
unsigned long flags;
struct drbd_request *req = bio->bi_private;
struct drbd_conf *mdev = req->mdev;
struct bio_and_error m;
enum drbd_req_event what;
int uptodate = bio_flagged(bio, BIO_UPTODATE);
if (error)
dev_warn(DEV, "p %s: error=%d\n",
bio_data_dir(bio) == WRITE ? "write" : "read", error);
if (!error && !uptodate) {
dev_warn(DEV, "p %s: setting error to -EIO\n",
bio_data_dir(bio) == WRITE ? "write" : "read");
/* strange behavior of some lower level drivers...
* fail the request by clearing the uptodate flag,
* but do not return any error?! */
error = -EIO;
}
/* to avoid recursion in __req_mod */
if (unlikely(error)) {
what = (bio_data_dir(bio) == WRITE)
? write_completed_with_error
: (bio_rw(bio) == READA)
? read_completed_with_error
: read_ahead_completed_with_error;
} else
what = completed_ok;
bio_put(req->private_bio);
req->private_bio = ERR_PTR(error);
spin_lock_irqsave(&mdev->req_lock, flags);
__req_mod(req, what, &m);
spin_unlock_irqrestore(&mdev->req_lock, flags);
if (m.bio)
complete_master_bio(mdev, &m);
}
int w_io_error(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_request *req = container_of(w, struct drbd_request, w);
/* NOTE: mdev->ldev can be NULL by the time we get here! */
/* D_ASSERT(mdev->ldev->dc.on_io_error != EP_PASS_ON); */
/* the only way this callback is scheduled is from _req_may_be_done,
* when it is done and had a local write error, see comments there */
drbd_req_free(req);
return TRUE;
}
int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_request *req = container_of(w, struct drbd_request, w);
/* We should not detach for read io-error,
* but try to WRITE the P_DATA_REPLY to the failed location,
* to give the disk the chance to relocate that block */
spin_lock_irq(&mdev->req_lock);
if (cancel ||
mdev->state.conn < C_CONNECTED ||
mdev->state.pdsk <= D_INCONSISTENT) {
_req_mod(req, send_canceled);
spin_unlock_irq(&mdev->req_lock);
dev_alert(DEV, "WE ARE LOST. Local IO failure, no peer.\n");
return 1;
}
spin_unlock_irq(&mdev->req_lock);
return w_send_read_req(mdev, w, 0);
}
int w_resync_inactive(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
ERR_IF(cancel) return 1;
dev_err(DEV, "resync inactive, but callback triggered??\n");
return 1; /* Simply ignore this! */
}
void drbd_csum(struct drbd_conf *mdev, struct crypto_hash *tfm, struct bio *bio, void *digest)
{
struct hash_desc desc;
struct scatterlist sg;
struct bio_vec *bvec;
int i;
desc.tfm = tfm;
desc.flags = 0;
sg_init_table(&sg, 1);
crypto_hash_init(&desc);
__bio_for_each_segment(bvec, bio, i, 0) {
sg_set_page(&sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset);
crypto_hash_update(&desc, &sg, sg.length);
}
crypto_hash_final(&desc, digest);
}
static int w_e_send_csum(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
int digest_size;
void *digest;
int ok;
D_ASSERT(e->block_id == DRBD_MAGIC + 0xbeef);
if (unlikely(cancel)) {
drbd_free_ee(mdev, e);
return 1;
}
if (likely(drbd_bio_uptodate(e->private_bio))) {
digest_size = crypto_hash_digestsize(mdev->csums_tfm);
digest = kmalloc(digest_size, GFP_NOIO);
if (digest) {
drbd_csum(mdev, mdev->csums_tfm, e->private_bio, digest);
inc_rs_pending(mdev);
ok = drbd_send_drequest_csum(mdev,
e->sector,
e->size,
digest,
digest_size,
P_CSUM_RS_REQUEST);
kfree(digest);
} else {
dev_err(DEV, "kmalloc() of digest failed.\n");
ok = 0;
}
} else
ok = 1;
drbd_free_ee(mdev, e);
if (unlikely(!ok))
dev_err(DEV, "drbd_send_drequest(..., csum) failed\n");
return ok;
}
#define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN)
static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size)
{
struct drbd_epoch_entry *e;
if (!get_ldev(mdev))
return 0;
/* GFP_TRY, because if there is no memory available right now, this may
* be rescheduled for later. It is "only" background resync, after all. */
e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY);
if (!e) {
put_ldev(mdev);
return 2;
}
spin_lock_irq(&mdev->req_lock);
list_add(&e->w.list, &mdev->read_ee);
spin_unlock_irq(&mdev->req_lock);
e->private_bio->bi_end_io = drbd_endio_read_sec;
e->private_bio->bi_rw = READ;
e->w.cb = w_e_send_csum;
mdev->read_cnt += size >> 9;
drbd_generic_make_request(mdev, DRBD_FAULT_RS_RD, e->private_bio);
return 1;
}
void resync_timer_fn(unsigned long data)
{
unsigned long flags;
struct drbd_conf *mdev = (struct drbd_conf *) data;
int queue;
spin_lock_irqsave(&mdev->req_lock, flags);
if (likely(!test_and_clear_bit(STOP_SYNC_TIMER, &mdev->flags))) {
queue = 1;
if (mdev->state.conn == C_VERIFY_S)
mdev->resync_work.cb = w_make_ov_request;
else
mdev->resync_work.cb = w_make_resync_request;
} else {
queue = 0;
mdev->resync_work.cb = w_resync_inactive;
}
spin_unlock_irqrestore(&mdev->req_lock, flags);
/* harmless race: list_empty outside data.work.q_lock */
if (list_empty(&mdev->resync_work.list) && queue)
drbd_queue_work(&mdev->data.work, &mdev->resync_work);
}
int w_make_resync_request(struct drbd_conf *mdev,
struct drbd_work *w, int cancel)
{
unsigned long bit;
sector_t sector;
const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
int max_segment_size = queue_max_segment_size(mdev->rq_queue);
int number, i, size, pe, mx;
int align, queued, sndbuf;
if (unlikely(cancel))
return 1;
if (unlikely(mdev->state.conn < C_CONNECTED)) {
dev_err(DEV, "Confused in w_make_resync_request()! cstate < Connected");
return 0;
}
if (mdev->state.conn != C_SYNC_TARGET)
dev_err(DEV, "%s in w_make_resync_request\n",
drbd_conn_str(mdev->state.conn));
if (!get_ldev(mdev)) {
/* Since we only need to access mdev->rsync a
get_ldev_if_state(mdev,D_FAILED) would be sufficient, but
to continue resync with a broken disk makes no sense at
all */
dev_err(DEV, "Disk broke down during resync!\n");
mdev->resync_work.cb = w_resync_inactive;
return 1;
}
number = SLEEP_TIME * mdev->sync_conf.rate / ((BM_BLOCK_SIZE/1024)*HZ);
pe = atomic_read(&mdev->rs_pending_cnt);
mutex_lock(&mdev->data.mutex);
if (mdev->data.socket)
mx = mdev->data.socket->sk->sk_rcvbuf / sizeof(struct p_block_req);
else
mx = 1;
mutex_unlock(&mdev->data.mutex);
/* For resync rates >160MB/sec, allow more pending RS requests */
if (number > mx)
mx = number;
/* Limit the number of pending RS requests to no more than the peer's receive buffer */
if ((pe + number) > mx) {
number = mx - pe;
}
for (i = 0; i < number; i++) {
/* Stop generating RS requests, when half of the send buffer is filled */
mutex_lock(&mdev->data.mutex);
if (mdev->data.socket) {
queued = mdev->data.socket->sk->sk_wmem_queued;
sndbuf = mdev->data.socket->sk->sk_sndbuf;
} else {
queued = 1;
sndbuf = 0;
}
mutex_unlock(&mdev->data.mutex);
if (queued > sndbuf / 2)
goto requeue;
next_sector:
size = BM_BLOCK_SIZE;
bit = drbd_bm_find_next(mdev, mdev->bm_resync_fo);
if (bit == -1UL) {
mdev->bm_resync_fo = drbd_bm_bits(mdev);
mdev->resync_work.cb = w_resync_inactive;
put_ldev(mdev);
return 1;
}
sector = BM_BIT_TO_SECT(bit);
if (drbd_try_rs_begin_io(mdev, sector)) {
mdev->bm_resync_fo = bit;
goto requeue;
}
mdev->bm_resync_fo = bit + 1;
if (unlikely(drbd_bm_test_bit(mdev, bit) == 0)) {
drbd_rs_complete_io(mdev, sector);
goto next_sector;
}
#if DRBD_MAX_SEGMENT_SIZE > BM_BLOCK_SIZE
/* try to find some adjacent bits.
* we stop if we have already the maximum req size.
*
* Additionally always align bigger requests, in order to
* be prepared for all stripe sizes of software RAIDs.
*
* we _do_ care about the agreed-upon q->max_segment_size
* here, as splitting up the requests on the other side is more
* difficult. the consequence is, that on lvm and md and other
* "indirect" devices, this is dead code, since
* q->max_segment_size will be PAGE_SIZE.
*/
align = 1;
for (;;) {
if (size + BM_BLOCK_SIZE > max_segment_size)
break;
/* Be always aligned */
if (sector & ((1<<(align+3))-1))
break;
/* do not cross extent boundaries */
if (((bit+1) & BM_BLOCKS_PER_BM_EXT_MASK) == 0)
break;
/* now, is it actually dirty, after all?
* caution, drbd_bm_test_bit is tri-state for some
* obscure reason; ( b == 0 ) would get the out-of-band
* only accidentally right because of the "oddly sized"
* adjustment below */
if (drbd_bm_test_bit(mdev, bit+1) != 1)
break;
bit++;
size += BM_BLOCK_SIZE;
if ((BM_BLOCK_SIZE << align) <= size)
align++;
i++;
}
/* if we merged some,
* reset the offset to start the next drbd_bm_find_next from */
if (size > BM_BLOCK_SIZE)
mdev->bm_resync_fo = bit + 1;
#endif
/* adjust very last sectors, in case we are oddly sized */
if (sector + (size>>9) > capacity)
size = (capacity-sector)<<9;
if (mdev->agreed_pro_version >= 89 && mdev->csums_tfm) {
switch (read_for_csum(mdev, sector, size)) {
case 0: /* Disk failure*/
put_ldev(mdev);
return 0;
case 2: /* Allocation failed */
drbd_rs_complete_io(mdev, sector);
mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
goto requeue;
/* case 1: everything ok */
}
} else {
inc_rs_pending(mdev);
if (!drbd_send_drequest(mdev, P_RS_DATA_REQUEST,
sector, size, ID_SYNCER)) {
dev_err(DEV, "drbd_send_drequest() failed, aborting...\n");
dec_rs_pending(mdev);
put_ldev(mdev);
return 0;
}
}
}
if (mdev->bm_resync_fo >= drbd_bm_bits(mdev)) {
/* last syncer _request_ was sent,
* but the P_RS_DATA_REPLY not yet received. sync will end (and
* next sync group will resume), as soon as we receive the last
* resync data block, and the last bit is cleared.
* until then resync "work" is "inactive" ...
*/
mdev->resync_work.cb = w_resync_inactive;
put_ldev(mdev);
return 1;
}
requeue:
mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME);
put_ldev(mdev);
return 1;
}
static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
int number, i, size;
sector_t sector;
const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
if (unlikely(cancel))
return 1;
if (unlikely(mdev->state.conn < C_CONNECTED)) {
dev_err(DEV, "Confused in w_make_ov_request()! cstate < Connected");
return 0;
}
number = SLEEP_TIME*mdev->sync_conf.rate / ((BM_BLOCK_SIZE/1024)*HZ);
if (atomic_read(&mdev->rs_pending_cnt) > number)
goto requeue;
number -= atomic_read(&mdev->rs_pending_cnt);
sector = mdev->ov_position;
for (i = 0; i < number; i++) {
if (sector >= capacity) {
mdev->resync_work.cb = w_resync_inactive;
return 1;
}
size = BM_BLOCK_SIZE;
if (drbd_try_rs_begin_io(mdev, sector)) {
mdev->ov_position = sector;
goto requeue;
}
if (sector + (size>>9) > capacity)
size = (capacity-sector)<<9;
inc_rs_pending(mdev);
if (!drbd_send_ov_request(mdev, sector, size)) {
dec_rs_pending(mdev);
return 0;
}
sector += BM_SECT_PER_BIT;
}
mdev->ov_position = sector;
requeue:
mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME);
return 1;
}
int w_ov_finished(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
kfree(w);
ov_oos_print(mdev);
drbd_resync_finished(mdev);
return 1;
}
static int w_resync_finished(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
kfree(w);
drbd_resync_finished(mdev);
return 1;
}
int drbd_resync_finished(struct drbd_conf *mdev)
{
unsigned long db, dt, dbdt;
unsigned long n_oos;
union drbd_state os, ns;
struct drbd_work *w;
char *khelper_cmd = NULL;
/* Remove all elements from the resync LRU. Since future actions
* might set bits in the (main) bitmap, then the entries in the
* resync LRU would be wrong. */
if (drbd_rs_del_all(mdev)) {
/* In case this is not possible now, most probably because
* there are P_RS_DATA_REPLY Packets lingering on the worker's
* queue (or even the read operations for those packets
* is not finished by now). Retry in 100ms. */
drbd_kick_lo(mdev);
__set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ / 10);
w = kmalloc(sizeof(struct drbd_work), GFP_ATOMIC);
if (w) {
w->cb = w_resync_finished;
drbd_queue_work(&mdev->data.work, w);
return 1;
}
dev_err(DEV, "Warn failed to drbd_rs_del_all() and to kmalloc(w).\n");
}
dt = (jiffies - mdev->rs_start - mdev->rs_paused) / HZ;
if (dt <= 0)
dt = 1;
db = mdev->rs_total;
dbdt = Bit2KB(db/dt);
mdev->rs_paused /= HZ;
if (!get_ldev(mdev))
goto out;
spin_lock_irq(&mdev->req_lock);
os = mdev->state;
/* This protects us against multiple calls (that can happen in the presence
of application IO), and against connectivity loss just before we arrive here. */
if (os.conn <= C_CONNECTED)
goto out_unlock;
ns = os;
ns.conn = C_CONNECTED;
dev_info(DEV, "%s done (total %lu sec; paused %lu sec; %lu K/sec)\n",
(os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) ?
"Online verify " : "Resync",
dt + mdev->rs_paused, mdev->rs_paused, dbdt);
n_oos = drbd_bm_total_weight(mdev);
if (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) {
if (n_oos) {
dev_alert(DEV, "Online verify found %lu %dk block out of sync!\n",
n_oos, Bit2KB(1));
khelper_cmd = "out-of-sync";
}
} else {
D_ASSERT((n_oos - mdev->rs_failed) == 0);
if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T)
khelper_cmd = "after-resync-target";
if (mdev->csums_tfm && mdev->rs_total) {
const unsigned long s = mdev->rs_same_csum;
const unsigned long t = mdev->rs_total;
const int ratio =
(t == 0) ? 0 :
(t < 100000) ? ((s*100)/t) : (s/(t/100));
dev_info(DEV, "%u %% had equal check sums, eliminated: %luK; "
"transferred %luK total %luK\n",
ratio,
Bit2KB(mdev->rs_same_csum),
Bit2KB(mdev->rs_total - mdev->rs_same_csum),
Bit2KB(mdev->rs_total));
}
}
if (mdev->rs_failed) {
dev_info(DEV, " %lu failed blocks\n", mdev->rs_failed);
if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) {
ns.disk = D_INCONSISTENT;
ns.pdsk = D_UP_TO_DATE;
} else {
ns.disk = D_UP_TO_DATE;
ns.pdsk = D_INCONSISTENT;
}
} else {
ns.disk = D_UP_TO_DATE;
ns.pdsk = D_UP_TO_DATE;
if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) {
if (mdev->p_uuid) {
int i;
for (i = UI_BITMAP ; i <= UI_HISTORY_END ; i++)
_drbd_uuid_set(mdev, i, mdev->p_uuid[i]);
drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_CURRENT]);
_drbd_uuid_set(mdev, UI_CURRENT, mdev->p_uuid[UI_CURRENT]);
} else {
dev_err(DEV, "mdev->p_uuid is NULL! BUG\n");
}
}
drbd_uuid_set_bm(mdev, 0UL);
if (mdev->p_uuid) {
/* Now the two UUID sets are equal, update what we
* know of the peer. */
int i;
for (i = UI_CURRENT ; i <= UI_HISTORY_END ; i++)
mdev->p_uuid[i] = mdev->ldev->md.uuid[i];
}
}
_drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
out_unlock:
spin_unlock_irq(&mdev->req_lock);
put_ldev(mdev);
out:
mdev->rs_total = 0;
mdev->rs_failed = 0;
mdev->rs_paused = 0;
mdev->ov_start_sector = 0;
if (test_and_clear_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags)) {
dev_warn(DEV, "Writing the whole bitmap, due to failed kmalloc\n");
drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished");
}
if (khelper_cmd)
drbd_khelper(mdev, khelper_cmd);
return 1;
}
/* helper */
static void move_to_net_ee_or_free(struct drbd_conf *mdev, struct drbd_epoch_entry *e)
{
if (drbd_bio_has_active_page(e->private_bio)) {
/* This might happen if sendpage() has not finished */
spin_lock_irq(&mdev->req_lock);
list_add_tail(&e->w.list, &mdev->net_ee);
spin_unlock_irq(&mdev->req_lock);
} else
drbd_free_ee(mdev, e);
}
/**
* w_e_end_data_req() - Worker callback, to send a P_DATA_REPLY packet in response to a P_DATA_REQUEST
* @mdev: DRBD device.
* @w: work object.
* @cancel: The connection will be closed anyways
*/
int w_e_end_data_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
int ok;
if (unlikely(cancel)) {
drbd_free_ee(mdev, e);
dec_unacked(mdev);
return 1;
}
if (likely(drbd_bio_uptodate(e->private_bio))) {
ok = drbd_send_block(mdev, P_DATA_REPLY, e);
} else {
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "Sending NegDReply. sector=%llus.\n",
(unsigned long long)e->sector);
ok = drbd_send_ack(mdev, P_NEG_DREPLY, e);
}
dec_unacked(mdev);
move_to_net_ee_or_free(mdev, e);
if (unlikely(!ok))
dev_err(DEV, "drbd_send_block() failed\n");
return ok;
}
/**
* w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUESTRS
* @mdev: DRBD device.
* @w: work object.
* @cancel: The connection will be closed anyways
*/
int w_e_end_rsdata_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
int ok;
if (unlikely(cancel)) {
drbd_free_ee(mdev, e);
dec_unacked(mdev);
return 1;
}
if (get_ldev_if_state(mdev, D_FAILED)) {
drbd_rs_complete_io(mdev, e->sector);
put_ldev(mdev);
}
if (likely(drbd_bio_uptodate(e->private_bio))) {
if (likely(mdev->state.pdsk >= D_INCONSISTENT)) {
inc_rs_pending(mdev);
ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e);
} else {
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "Not sending RSDataReply, "
"partner DISKLESS!\n");
ok = 1;
}
} else {
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "Sending NegRSDReply. sector %llus.\n",
(unsigned long long)e->sector);
ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e);
/* update resync data with failure */
drbd_rs_failed_io(mdev, e->sector, e->size);
}
dec_unacked(mdev);
move_to_net_ee_or_free(mdev, e);
if (unlikely(!ok))
dev_err(DEV, "drbd_send_block() failed\n");
return ok;
}
int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
struct digest_info *di;
int digest_size;
void *digest = NULL;
int ok, eq = 0;
if (unlikely(cancel)) {
drbd_free_ee(mdev, e);
dec_unacked(mdev);
return 1;
}
drbd_rs_complete_io(mdev, e->sector);
di = (struct digest_info *)(unsigned long)e->block_id;
if (likely(drbd_bio_uptodate(e->private_bio))) {
/* quick hack to try to avoid a race against reconfiguration.
* a real fix would be much more involved,
* introducing more locking mechanisms */
if (mdev->csums_tfm) {
digest_size = crypto_hash_digestsize(mdev->csums_tfm);
D_ASSERT(digest_size == di->digest_size);
digest = kmalloc(digest_size, GFP_NOIO);
}
if (digest) {
drbd_csum(mdev, mdev->csums_tfm, e->private_bio, digest);
eq = !memcmp(digest, di->digest, digest_size);
kfree(digest);
}
if (eq) {
drbd_set_in_sync(mdev, e->sector, e->size);
/* rs_same_csums unit is BM_BLOCK_SIZE */
mdev->rs_same_csum += e->size >> BM_BLOCK_SHIFT;
ok = drbd_send_ack(mdev, P_RS_IS_IN_SYNC, e);
} else {
inc_rs_pending(mdev);
e->block_id = ID_SYNCER;
ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e);
}
} else {
ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e);
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "Sending NegDReply. I guess it gets messy.\n");
}
dec_unacked(mdev);
kfree(di);
move_to_net_ee_or_free(mdev, e);
if (unlikely(!ok))
dev_err(DEV, "drbd_send_block/ack() failed\n");
return ok;
}
int w_e_end_ov_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
int digest_size;
void *digest;
int ok = 1;
if (unlikely(cancel))
goto out;
if (unlikely(!drbd_bio_uptodate(e->private_bio)))
goto out;
digest_size = crypto_hash_digestsize(mdev->verify_tfm);
/* FIXME if this allocation fails, online verify will not terminate! */
digest = kmalloc(digest_size, GFP_NOIO);
if (digest) {
drbd_csum(mdev, mdev->verify_tfm, e->private_bio, digest);
inc_rs_pending(mdev);
ok = drbd_send_drequest_csum(mdev, e->sector, e->size,
digest, digest_size, P_OV_REPLY);
if (!ok)
dec_rs_pending(mdev);
kfree(digest);
}
out:
drbd_free_ee(mdev, e);
dec_unacked(mdev);
return ok;
}
void drbd_ov_oos_found(struct drbd_conf *mdev, sector_t sector, int size)
{
if (mdev->ov_last_oos_start + mdev->ov_last_oos_size == sector) {
mdev->ov_last_oos_size += size>>9;
} else {
mdev->ov_last_oos_start = sector;
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)
{
struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w);
struct digest_info *di;
int digest_size;
void *digest;
int ok, eq = 0;
if (unlikely(cancel)) {
drbd_free_ee(mdev, e);
dec_unacked(mdev);
return 1;
}
/* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all
* the resync lru has been cleaned up already */
drbd_rs_complete_io(mdev, e->sector);
di = (struct digest_info *)(unsigned long)e->block_id;
if (likely(drbd_bio_uptodate(e->private_bio))) {
digest_size = crypto_hash_digestsize(mdev->verify_tfm);
digest = kmalloc(digest_size, GFP_NOIO);
if (digest) {
drbd_csum(mdev, mdev->verify_tfm, e->private_bio, digest);
D_ASSERT(digest_size == di->digest_size);
eq = !memcmp(digest, di->digest, digest_size);
kfree(digest);
}
} else {
ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e);
if (__ratelimit(&drbd_ratelimit_state))
dev_err(DEV, "Sending NegDReply. I guess it gets messy.\n");
}
dec_unacked(mdev);
kfree(di);
if (!eq)
drbd_ov_oos_found(mdev, e->sector, e->size);
else
ov_oos_print(mdev);
ok = drbd_send_ack_ex(mdev, P_OV_RESULT, e->sector, e->size,
eq ? ID_IN_SYNC : ID_OUT_OF_SYNC);
drbd_free_ee(mdev, e);
if (--mdev->ov_left == 0) {
ov_oos_print(mdev);
drbd_resync_finished(mdev);
}
return ok;
}
int w_prev_work_done(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_wq_barrier *b = container_of(w, struct drbd_wq_barrier, w);
complete(&b->done);
return 1;
}
int w_send_barrier(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_tl_epoch *b = container_of(w, struct drbd_tl_epoch, w);
struct p_barrier *p = &mdev->data.sbuf.barrier;
int ok = 1;
/* really avoid racing with tl_clear. w.cb may have been referenced
* just before it was reassigned and re-queued, so double check that.
* actually, this race was harmless, since we only try to send the
* barrier packet here, and otherwise do nothing with the object.
* but compare with the head of w_clear_epoch */
spin_lock_irq(&mdev->req_lock);
if (w->cb != w_send_barrier || mdev->state.conn < C_CONNECTED)
cancel = 1;
spin_unlock_irq(&mdev->req_lock);
if (cancel)
return 1;
if (!drbd_get_data_sock(mdev))
return 0;
p->barrier = b->br_number;
/* inc_ap_pending was done where this was queued.
* dec_ap_pending will be done in got_BarrierAck
* or (on connection loss) in w_clear_epoch. */
ok = _drbd_send_cmd(mdev, mdev->data.socket, P_BARRIER,
(struct p_header *)p, sizeof(*p), 0);
drbd_put_data_sock(mdev);
return ok;
}
int w_send_write_hint(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
if (cancel)
return 1;
return drbd_send_short_cmd(mdev, P_UNPLUG_REMOTE);
}
/**
* w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request
* @mdev: DRBD device.
* @w: work object.
* @cancel: The connection will be closed anyways
*/
int w_send_dblock(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_request *req = container_of(w, struct drbd_request, w);
int ok;
if (unlikely(cancel)) {
req_mod(req, send_canceled);
return 1;
}
ok = drbd_send_dblock(mdev, req);
req_mod(req, ok ? handed_over_to_network : send_failed);
return ok;
}
/**
* w_send_read_req() - Worker callback to send a read request (P_DATA_REQUEST) packet
* @mdev: DRBD device.
* @w: work object.
* @cancel: The connection will be closed anyways
*/
int w_send_read_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
struct drbd_request *req = container_of(w, struct drbd_request, w);
int ok;
if (unlikely(cancel)) {
req_mod(req, send_canceled);
return 1;
}
ok = drbd_send_drequest(mdev, P_DATA_REQUEST, req->sector, req->size,
(unsigned long)req);
if (!ok) {
/* ?? we set C_TIMEOUT or C_BROKEN_PIPE in drbd_send();
* so this is probably redundant */
if (mdev->state.conn >= C_CONNECTED)
drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE));
}
req_mod(req, ok ? handed_over_to_network : send_failed);
return ok;
}
static int _drbd_may_sync_now(struct drbd_conf *mdev)
{
struct drbd_conf *odev = mdev;
while (1) {
if (odev->sync_conf.after == -1)
return 1;
odev = minor_to_mdev(odev->sync_conf.after);
ERR_IF(!odev) return 1;
if ((odev->state.conn >= C_SYNC_SOURCE &&
odev->state.conn <= C_PAUSED_SYNC_T) ||
odev->state.aftr_isp || odev->state.peer_isp ||
odev->state.user_isp)
return 0;
}
}
/**
* _drbd_pause_after() - Pause resync on all devices that may not resync now
* @mdev: DRBD device.
*
* Called from process context only (admin command and after_state_ch).
*/
static int _drbd_pause_after(struct drbd_conf *mdev)
{
struct drbd_conf *odev;
int i, rv = 0;
for (i = 0; i < minor_count; i++) {
odev = minor_to_mdev(i);
if (!odev)
continue;
if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
continue;
if (!_drbd_may_sync_now(odev))
rv |= (__drbd_set_state(_NS(odev, aftr_isp, 1), CS_HARD, NULL)
!= SS_NOTHING_TO_DO);
}
return rv;
}
/**
* _drbd_resume_next() - Resume resync on all devices that may resync now
* @mdev: DRBD device.
*
* Called from process context only (admin command and worker).
*/
static int _drbd_resume_next(struct drbd_conf *mdev)
{
struct drbd_conf *odev;
int i, rv = 0;
for (i = 0; i < minor_count; i++) {
odev = minor_to_mdev(i);
if (!odev)
continue;
if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
continue;
if (odev->state.aftr_isp) {
if (_drbd_may_sync_now(odev))
rv |= (__drbd_set_state(_NS(odev, aftr_isp, 0),
CS_HARD, NULL)
!= SS_NOTHING_TO_DO) ;
}
}
return rv;
}
void resume_next_sg(struct drbd_conf *mdev)
{
write_lock_irq(&global_state_lock);
_drbd_resume_next(mdev);
write_unlock_irq(&global_state_lock);
}
void suspend_other_sg(struct drbd_conf *mdev)
{
write_lock_irq(&global_state_lock);
_drbd_pause_after(mdev);
write_unlock_irq(&global_state_lock);
}
static int sync_after_error(struct drbd_conf *mdev, int o_minor)
{
struct drbd_conf *odev;
if (o_minor == -1)
return NO_ERROR;
if (o_minor < -1 || minor_to_mdev(o_minor) == NULL)
return ERR_SYNC_AFTER;
/* check for loops */
odev = minor_to_mdev(o_minor);
while (1) {
if (odev == mdev)
return ERR_SYNC_AFTER_CYCLE;
/* dependency chain ends here, no cycles. */
if (odev->sync_conf.after == -1)
return NO_ERROR;
/* follow the dependency chain */
odev = minor_to_mdev(odev->sync_conf.after);
}
}
int drbd_alter_sa(struct drbd_conf *mdev, int na)
{
int changes;
int retcode;
write_lock_irq(&global_state_lock);
retcode = sync_after_error(mdev, na);
if (retcode == NO_ERROR) {
mdev->sync_conf.after = na;
do {
changes = _drbd_pause_after(mdev);
changes |= _drbd_resume_next(mdev);
} while (changes);
}
write_unlock_irq(&global_state_lock);
return retcode;
}
static void ping_peer(struct drbd_conf *mdev)
{
clear_bit(GOT_PING_ACK, &mdev->flags);
request_ping(mdev);
wait_event(mdev->misc_wait,
test_bit(GOT_PING_ACK, &mdev->flags) || mdev->state.conn < C_CONNECTED);
}
/**
* drbd_start_resync() - Start the resync process
* @mdev: DRBD device.
* @side: Either C_SYNC_SOURCE or C_SYNC_TARGET
*
* This function might bring you directly into one of the
* C_PAUSED_SYNC_* states.
*/
void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
{
union drbd_state ns;
int r;
if (mdev->state.conn >= C_SYNC_SOURCE) {
dev_err(DEV, "Resync already running!\n");
return;
}
/* In case a previous resync run was aborted by an IO error/detach on the peer. */
drbd_rs_cancel_all(mdev);
if (side == C_SYNC_TARGET) {
/* Since application IO was locked out during C_WF_BITMAP_T and
C_WF_SYNC_UUID we are still unmodified. Before going to C_SYNC_TARGET
we check that we might make the data inconsistent. */
r = drbd_khelper(mdev, "before-resync-target");
r = (r >> 8) & 0xff;
if (r > 0) {
dev_info(DEV, "before-resync-target handler returned %d, "
"dropping connection.\n", r);
drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
return;
}
}
drbd_state_lock(mdev);
if (!get_ldev_if_state(mdev, D_NEGOTIATING)) {
drbd_state_unlock(mdev);
return;
}
if (side == C_SYNC_TARGET) {
mdev->bm_resync_fo = 0;
} else /* side == C_SYNC_SOURCE */ {
u64 uuid;
get_random_bytes(&uuid, sizeof(u64));
drbd_uuid_set(mdev, UI_BITMAP, uuid);
drbd_send_sync_uuid(mdev, uuid);
D_ASSERT(mdev->state.disk == D_UP_TO_DATE);
}
write_lock_irq(&global_state_lock);
ns = mdev->state;
ns.aftr_isp = !_drbd_may_sync_now(mdev);
ns.conn = side;
if (side == C_SYNC_TARGET)
ns.disk = D_INCONSISTENT;
else /* side == C_SYNC_SOURCE */
ns.pdsk = D_INCONSISTENT;
r = __drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
ns = mdev->state;
if (ns.conn < C_CONNECTED)
r = SS_UNKNOWN_ERROR;
if (r == SS_SUCCESS) {
mdev->rs_total =
mdev->rs_mark_left = drbd_bm_total_weight(mdev);
mdev->rs_failed = 0;
mdev->rs_paused = 0;
mdev->rs_start =
mdev->rs_mark_time = jiffies;
mdev->rs_same_csum = 0;
_drbd_pause_after(mdev);
}
write_unlock_irq(&global_state_lock);
put_ldev(mdev);
if (r == SS_SUCCESS) {
dev_info(DEV, "Began resync as %s (will sync %lu KB [%lu bits set]).\n",
drbd_conn_str(ns.conn),
(unsigned long) mdev->rs_total << (BM_BLOCK_SHIFT-10),
(unsigned long) mdev->rs_total);
if (mdev->rs_total == 0) {
/* Peer still reachable? Beware of failing before-resync-target handlers! */
ping_peer(mdev);
drbd_resync_finished(mdev);
}
/* ns.conn may already be != mdev->state.conn,
* we may have been paused in between, or become paused until
* the timer triggers.
* No matter, that is handled in resync_timer_fn() */
if (ns.conn == C_SYNC_TARGET)
mod_timer(&mdev->resync_timer, jiffies);
drbd_md_sync(mdev);
}
drbd_state_unlock(mdev);
}
int drbd_worker(struct drbd_thread *thi)
{
struct drbd_conf *mdev = thi->mdev;
struct drbd_work *w = NULL;
LIST_HEAD(work_list);
int intr = 0, i;
sprintf(current->comm, "drbd%d_worker", mdev_to_minor(mdev));
while (get_t_state(thi) == Running) {
drbd_thread_current_set_cpu(mdev);
if (down_trylock(&mdev->data.work.s)) {
mutex_lock(&mdev->data.mutex);
if (mdev->data.socket && !mdev->net_conf->no_cork)
drbd_tcp_uncork(mdev->data.socket);
mutex_unlock(&mdev->data.mutex);
intr = down_interruptible(&mdev->data.work.s);
mutex_lock(&mdev->data.mutex);
if (mdev->data.socket && !mdev->net_conf->no_cork)
drbd_tcp_cork(mdev->data.socket);
mutex_unlock(&mdev->data.mutex);
}
if (intr) {
D_ASSERT(intr == -EINTR);
flush_signals(current);
ERR_IF (get_t_state(thi) == Running)
continue;
break;
}
if (get_t_state(thi) != Running)
break;
/* With this break, we have done a down() but not consumed
the entry from the list. The cleanup code takes care of
this... */
w = NULL;
spin_lock_irq(&mdev->data.work.q_lock);
ERR_IF(list_empty(&mdev->data.work.q)) {
/* something terribly wrong in our logic.
* we were able to down() the semaphore,
* but the list is empty... doh.
*
* what is the best thing to do now?
* try again from scratch, restarting the receiver,
* asender, whatnot? could break even more ugly,
* e.g. when we are primary, but no good local data.
*
* I'll try to get away just starting over this loop.
*/
spin_unlock_irq(&mdev->data.work.q_lock);
continue;
}
w = list_entry(mdev->data.work.q.next, struct drbd_work, list);
list_del_init(&w->list);
spin_unlock_irq(&mdev->data.work.q_lock);
if (!w->cb(mdev, w, mdev->state.conn < C_CONNECTED)) {
/* dev_warn(DEV, "worker: a callback failed! \n"); */
if (mdev->state.conn >= C_CONNECTED)
drbd_force_state(mdev,
NS(conn, C_NETWORK_FAILURE));
}
}
D_ASSERT(test_bit(DEVICE_DYING, &mdev->flags));
D_ASSERT(test_bit(CONFIG_PENDING, &mdev->flags));
spin_lock_irq(&mdev->data.work.q_lock);
i = 0;
while (!list_empty(&mdev->data.work.q)) {
list_splice_init(&mdev->data.work.q, &work_list);
spin_unlock_irq(&mdev->data.work.q_lock);
while (!list_empty(&work_list)) {
w = list_entry(work_list.next, struct drbd_work, list);
list_del_init(&w->list);
w->cb(mdev, w, 1);
i++; /* dead debugging code */
}
spin_lock_irq(&mdev->data.work.q_lock);
}
sema_init(&mdev->data.work.s, 0);
/* DANGEROUS race: if someone did queue his work within the spinlock,
* but up() ed outside the spinlock, we could get an up() on the
* semaphore without corresponding list entry.
* So don't do that.
*/
spin_unlock_irq(&mdev->data.work.q_lock);
D_ASSERT(mdev->state.disk == D_DISKLESS && mdev->state.conn == C_STANDALONE);
/* _drbd_set_state only uses stop_nowait.
* wait here for the Exiting receiver. */
drbd_thread_stop(&mdev->receiver);
drbd_mdev_cleanup(mdev);
dev_info(DEV, "worker terminated\n");
clear_bit(DEVICE_DYING, &mdev->flags);
clear_bit(CONFIG_PENDING, &mdev->flags);
wake_up(&mdev->state_wait);
return 0;
}
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