diff options
Diffstat (limited to 'drivers/block/drbd/drbd_worker.c')
| -rw-r--r-- | drivers/block/drbd/drbd_worker.c | 2156 |
1 files changed, 2156 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c new file mode 100644 index 000000000..d0fae55d8 --- /dev/null +++ b/drivers/block/drbd/drbd_worker.c @@ -0,0 +1,2156 @@ +/* + 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/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_protocol.h" +#include "drbd_req.h" + +static int make_ov_request(struct drbd_device *, int); +static int make_resync_request(struct drbd_device *, int); + +/* endio handlers: + * drbd_md_endio (defined here) + * drbd_request_endio (defined here) + * drbd_peer_request_endio (defined here) + * drbd_bm_endio (defined 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 resync 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_endio(struct bio *bio, int error) +{ + struct drbd_device *device; + + device = bio->bi_private; + device->md_io.error = error; + + /* We grabbed an extra reference in _drbd_md_sync_page_io() to be able + * to timeout on the lower level device, and eventually detach from it. + * If this io completion runs after that timeout expired, this + * drbd_md_put_buffer() may allow us to finally try and re-attach. + * During normal operation, this only puts that extra reference + * down to 1 again. + * Make sure we first drop the reference, and only then signal + * completion, or we may (in drbd_al_read_log()) cycle so fast into the + * next drbd_md_sync_page_io(), that we trigger the + * ASSERT(atomic_read(&device->md_io_in_use) == 1) there. + */ + drbd_md_put_buffer(device); + device->md_io.done = 1; + wake_up(&device->misc_wait); + bio_put(bio); + if (device->ldev) /* special case: drbd_md_read() during drbd_adm_attach() */ + put_ldev(device); +} + +/* reads on behalf of the partner, + * "submitted" by the receiver + */ +static void drbd_endio_read_sec_final(struct drbd_peer_request *peer_req) __releases(local) +{ + unsigned long flags = 0; + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + + spin_lock_irqsave(&device->resource->req_lock, flags); + device->read_cnt += peer_req->i.size >> 9; + list_del(&peer_req->w.list); + if (list_empty(&device->read_ee)) + wake_up(&device->ee_wait); + if (test_bit(__EE_WAS_ERROR, &peer_req->flags)) + __drbd_chk_io_error(device, DRBD_READ_ERROR); + spin_unlock_irqrestore(&device->resource->req_lock, flags); + + drbd_queue_work(&peer_device->connection->sender_work, &peer_req->w); + put_ldev(device); +} + +/* writes on behalf of the partner, or resync writes, + * "submitted" by the receiver, final stage. */ +void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req) __releases(local) +{ + unsigned long flags = 0; + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + struct drbd_interval i; + int do_wake; + u64 block_id; + int do_al_complete_io; + + /* after we moved peer_req to done_ee, + * we may no longer access it, + * it may be freed/reused already! + * (as soon as we release the req_lock) */ + i = peer_req->i; + do_al_complete_io = peer_req->flags & EE_CALL_AL_COMPLETE_IO; + block_id = peer_req->block_id; + peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO; + + spin_lock_irqsave(&device->resource->req_lock, flags); + device->writ_cnt += peer_req->i.size >> 9; + list_move_tail(&peer_req->w.list, &device->done_ee); + + /* + * Do not remove from the write_requests tree here: we did not send the + * Ack yet and did not wake possibly waiting conflicting requests. + * Removed from the tree from "drbd_process_done_ee" within the + * appropriate dw.cb (e_end_block/e_end_resync_block) or from + * _drbd_clear_done_ee. + */ + + do_wake = list_empty(block_id == ID_SYNCER ? &device->sync_ee : &device->active_ee); + + /* FIXME do we want to detach for failed REQ_DISCARD? + * ((peer_req->flags & (EE_WAS_ERROR|EE_IS_TRIM)) == EE_WAS_ERROR) */ + if (peer_req->flags & EE_WAS_ERROR) + __drbd_chk_io_error(device, DRBD_WRITE_ERROR); + spin_unlock_irqrestore(&device->resource->req_lock, flags); + + if (block_id == ID_SYNCER) + drbd_rs_complete_io(device, i.sector); + + if (do_wake) + wake_up(&device->ee_wait); + + if (do_al_complete_io) + drbd_al_complete_io(device, &i); + + wake_asender(peer_device->connection); + put_ldev(device); +} + +/* writes on behalf of the partner, or resync writes, + * "submitted" by the receiver. + */ +void drbd_peer_request_endio(struct bio *bio, int error) +{ + struct drbd_peer_request *peer_req = bio->bi_private; + struct drbd_device *device = peer_req->peer_device->device; + int uptodate = bio_flagged(bio, BIO_UPTODATE); + int is_write = bio_data_dir(bio) == WRITE; + int is_discard = !!(bio->bi_rw & REQ_DISCARD); + + if (error && __ratelimit(&drbd_ratelimit_state)) + drbd_warn(device, "%s: error=%d s=%llus\n", + is_write ? (is_discard ? "discard" : "write") + : "read", error, + (unsigned long long)peer_req->i.sector); + if (!error && !uptodate) { + if (__ratelimit(&drbd_ratelimit_state)) + drbd_warn(device, "%s: setting error to -EIO s=%llus\n", + is_write ? "write" : "read", + (unsigned long long)peer_req->i.sector); + /* strange behavior of some lower level drivers... + * fail the request by clearing the uptodate flag, + * but do not return any error?! */ + error = -EIO; + } + + if (error) + set_bit(__EE_WAS_ERROR, &peer_req->flags); + + bio_put(bio); /* no need for the bio anymore */ + if (atomic_dec_and_test(&peer_req->pending_bios)) { + if (is_write) + drbd_endio_write_sec_final(peer_req); + else + drbd_endio_read_sec_final(peer_req); + } +} + +/* read, readA or write requests on R_PRIMARY coming from drbd_make_request + */ +void drbd_request_endio(struct bio *bio, int error) +{ + unsigned long flags; + struct drbd_request *req = bio->bi_private; + struct drbd_device *device = req->device; + struct bio_and_error m; + enum drbd_req_event what; + int uptodate = bio_flagged(bio, BIO_UPTODATE); + + if (!error && !uptodate) { + drbd_warn(device, "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; + } + + + /* If this request was aborted locally before, + * but now was completed "successfully", + * chances are that this caused arbitrary data corruption. + * + * "aborting" requests, or force-detaching the disk, is intended for + * completely blocked/hung local backing devices which do no longer + * complete requests at all, not even do error completions. In this + * situation, usually a hard-reset and failover is the only way out. + * + * By "aborting", basically faking a local error-completion, + * we allow for a more graceful swichover by cleanly migrating services. + * Still the affected node has to be rebooted "soon". + * + * By completing these requests, we allow the upper layers to re-use + * the associated data pages. + * + * If later the local backing device "recovers", and now DMAs some data + * from disk into the original request pages, in the best case it will + * just put random data into unused pages; but typically it will corrupt + * meanwhile completely unrelated data, causing all sorts of damage. + * + * Which means delayed successful completion, + * especially for READ requests, + * is a reason to panic(). + * + * We assume that a delayed *error* completion is OK, + * though we still will complain noisily about it. + */ + if (unlikely(req->rq_state & RQ_LOCAL_ABORTED)) { + if (__ratelimit(&drbd_ratelimit_state)) + drbd_emerg(device, "delayed completion of aborted local request; disk-timeout may be too aggressive\n"); + + if (!error) + panic("possible random memory corruption caused by delayed completion of aborted local request\n"); + } + + /* to avoid recursion in __req_mod */ + if (unlikely(error)) { + if (bio->bi_rw & REQ_DISCARD) + what = (error == -EOPNOTSUPP) + ? DISCARD_COMPLETED_NOTSUPP + : DISCARD_COMPLETED_WITH_ERROR; + else + what = (bio_data_dir(bio) == WRITE) + ? WRITE_COMPLETED_WITH_ERROR + : (bio_rw(bio) == READ) + ? READ_COMPLETED_WITH_ERROR + : READ_AHEAD_COMPLETED_WITH_ERROR; + } else + what = COMPLETED_OK; + + bio_put(req->private_bio); + req->private_bio = ERR_PTR(error); + + /* not req_mod(), we need irqsave here! */ + spin_lock_irqsave(&device->resource->req_lock, flags); + __req_mod(req, what, &m); + spin_unlock_irqrestore(&device->resource->req_lock, flags); + put_ldev(device); + + if (m.bio) + complete_master_bio(device, &m); +} + +void drbd_csum_ee(struct crypto_hash *tfm, struct drbd_peer_request *peer_req, void *digest) +{ + struct hash_desc desc; + struct scatterlist sg; + struct page *page = peer_req->pages; + struct page *tmp; + unsigned len; + + desc.tfm = tfm; + desc.flags = 0; + + sg_init_table(&sg, 1); + crypto_hash_init(&desc); + + while ((tmp = page_chain_next(page))) { + /* all but the last page will be fully used */ + sg_set_page(&sg, page, PAGE_SIZE, 0); + crypto_hash_update(&desc, &sg, sg.length); + page = tmp; + } + /* and now the last, possibly only partially used page */ + len = peer_req->i.size & (PAGE_SIZE - 1); + sg_set_page(&sg, page, len ?: PAGE_SIZE, 0); + crypto_hash_update(&desc, &sg, sg.length); + crypto_hash_final(&desc, digest); +} + +void drbd_csum_bio(struct crypto_hash *tfm, struct bio *bio, void *digest) +{ + struct hash_desc desc; + struct scatterlist sg; + struct bio_vec bvec; + struct bvec_iter iter; + + desc.tfm = tfm; + desc.flags = 0; + + sg_init_table(&sg, 1); + crypto_hash_init(&desc); + + bio_for_each_segment(bvec, bio, iter) { + 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); +} + +/* MAYBE merge common code with w_e_end_ov_req */ +static int w_e_send_csum(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + int digest_size; + void *digest; + int err = 0; + + if (unlikely(cancel)) + goto out; + + if (unlikely((peer_req->flags & EE_WAS_ERROR) != 0)) + goto out; + + digest_size = crypto_hash_digestsize(peer_device->connection->csums_tfm); + digest = kmalloc(digest_size, GFP_NOIO); + if (digest) { + sector_t sector = peer_req->i.sector; + unsigned int size = peer_req->i.size; + drbd_csum_ee(peer_device->connection->csums_tfm, peer_req, digest); + /* Free peer_req and pages before send. + * In case we block on congestion, we could otherwise run into + * some distributed deadlock, if the other side blocks on + * congestion as well, because our receiver blocks in + * drbd_alloc_pages due to pp_in_use > max_buffers. */ + drbd_free_peer_req(device, peer_req); + peer_req = NULL; + inc_rs_pending(device); + err = drbd_send_drequest_csum(peer_device, sector, size, + digest, digest_size, + P_CSUM_RS_REQUEST); + kfree(digest); + } else { + drbd_err(device, "kmalloc() of digest failed.\n"); + err = -ENOMEM; + } + +out: + if (peer_req) + drbd_free_peer_req(device, peer_req); + + if (unlikely(err)) + drbd_err(device, "drbd_send_drequest(..., csum) failed\n"); + return err; +} + +#define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN) + +static int read_for_csum(struct drbd_peer_device *peer_device, sector_t sector, int size) +{ + struct drbd_device *device = peer_device->device; + struct drbd_peer_request *peer_req; + + if (!get_ldev(device)) + return -EIO; + + /* GFP_TRY, because if there is no memory available right now, this may + * be rescheduled for later. It is "only" background resync, after all. */ + peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER /* unused */, sector, + size, true /* has real payload */, GFP_TRY); + if (!peer_req) + goto defer; + + peer_req->w.cb = w_e_send_csum; + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&peer_req->w.list, &device->read_ee); + spin_unlock_irq(&device->resource->req_lock); + + atomic_add(size >> 9, &device->rs_sect_ev); + if (drbd_submit_peer_request(device, peer_req, READ, DRBD_FAULT_RS_RD) == 0) + return 0; + + /* If it failed because of ENOMEM, retry should help. If it failed + * because bio_add_page failed (probably broken lower level driver), + * retry may or may not help. + * If it does not, you may need to force disconnect. */ + spin_lock_irq(&device->resource->req_lock); + list_del(&peer_req->w.list); + spin_unlock_irq(&device->resource->req_lock); + + drbd_free_peer_req(device, peer_req); +defer: + put_ldev(device); + return -EAGAIN; +} + +int w_resync_timer(struct drbd_work *w, int cancel) +{ + struct drbd_device *device = + container_of(w, struct drbd_device, resync_work); + + switch (device->state.conn) { + case C_VERIFY_S: + make_ov_request(device, cancel); + break; + case C_SYNC_TARGET: + make_resync_request(device, cancel); + break; + } + + return 0; +} + +void resync_timer_fn(unsigned long data) +{ + struct drbd_device *device = (struct drbd_device *) data; + + drbd_queue_work_if_unqueued( + &first_peer_device(device)->connection->sender_work, + &device->resync_work); +} + +static void fifo_set(struct fifo_buffer *fb, int value) +{ + int i; + + for (i = 0; i < fb->size; i++) + fb->values[i] = value; +} + +static int fifo_push(struct fifo_buffer *fb, int value) +{ + int ov; + + ov = fb->values[fb->head_index]; + fb->values[fb->head_index++] = value; + + if (fb->head_index >= fb->size) + fb->head_index = 0; + + return ov; +} + +static void fifo_add_val(struct fifo_buffer *fb, int value) +{ + int i; + + for (i = 0; i < fb->size; i++) + fb->values[i] += value; +} + +struct fifo_buffer *fifo_alloc(int fifo_size) +{ + struct fifo_buffer *fb; + + fb = kzalloc(sizeof(struct fifo_buffer) + sizeof(int) * fifo_size, GFP_NOIO); + if (!fb) + return NULL; + + fb->head_index = 0; + fb->size = fifo_size; + fb->total = 0; + + return fb; +} + +static int drbd_rs_controller(struct drbd_device *device, unsigned int sect_in) +{ + struct disk_conf *dc; + unsigned int want; /* The number of sectors we want in-flight */ + int req_sect; /* Number of sectors to request in this turn */ + int correction; /* Number of sectors more we need in-flight */ + int cps; /* correction per invocation of drbd_rs_controller() */ + int steps; /* Number of time steps to plan ahead */ + int curr_corr; + int max_sect; + struct fifo_buffer *plan; + + dc = rcu_dereference(device->ldev->disk_conf); + plan = rcu_dereference(device->rs_plan_s); + + steps = plan->size; /* (dc->c_plan_ahead * 10 * SLEEP_TIME) / HZ; */ + + if (device->rs_in_flight + sect_in == 0) { /* At start of resync */ + want = ((dc->resync_rate * 2 * SLEEP_TIME) / HZ) * steps; + } else { /* normal path */ + want = dc->c_fill_target ? dc->c_fill_target : + sect_in * dc->c_delay_target * HZ / (SLEEP_TIME * 10); + } + + correction = want - device->rs_in_flight - plan->total; + + /* Plan ahead */ + cps = correction / steps; + fifo_add_val(plan, cps); + plan->total += cps * steps; + + /* What we do in this step */ + curr_corr = fifo_push(plan, 0); + plan->total -= curr_corr; + + req_sect = sect_in + curr_corr; + if (req_sect < 0) + req_sect = 0; + + max_sect = (dc->c_max_rate * 2 * SLEEP_TIME) / HZ; + if (req_sect > max_sect) + req_sect = max_sect; + + /* + drbd_warn(device, "si=%u if=%d wa=%u co=%d st=%d cps=%d pl=%d cc=%d rs=%d\n", + sect_in, device->rs_in_flight, want, correction, + steps, cps, device->rs_planed, curr_corr, req_sect); + */ + + return req_sect; +} + +static int drbd_rs_number_requests(struct drbd_device *device) +{ + unsigned int sect_in; /* Number of sectors that came in since the last turn */ + int number, mxb; + + sect_in = atomic_xchg(&device->rs_sect_in, 0); + device->rs_in_flight -= sect_in; + + rcu_read_lock(); + mxb = drbd_get_max_buffers(device) / 2; + if (rcu_dereference(device->rs_plan_s)->size) { + number = drbd_rs_controller(device, sect_in) >> (BM_BLOCK_SHIFT - 9); + device->c_sync_rate = number * HZ * (BM_BLOCK_SIZE / 1024) / SLEEP_TIME; + } else { + device->c_sync_rate = rcu_dereference(device->ldev->disk_conf)->resync_rate; + number = SLEEP_TIME * device->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ); + } + rcu_read_unlock(); + + /* Don't have more than "max-buffers"/2 in-flight. + * Otherwise we may cause the remote site to stall on drbd_alloc_pages(), + * potentially causing a distributed deadlock on congestion during + * online-verify or (checksum-based) resync, if max-buffers, + * socket buffer sizes and resync rate settings are mis-configured. */ + + /* note that "number" is in units of "BM_BLOCK_SIZE" (which is 4k), + * mxb (as used here, and in drbd_alloc_pages on the peer) is + * "number of pages" (typically also 4k), + * but "rs_in_flight" is in "sectors" (512 Byte). */ + if (mxb - device->rs_in_flight/8 < number) + number = mxb - device->rs_in_flight/8; + + return number; +} + +static int make_resync_request(struct drbd_device *const device, int cancel) +{ + struct drbd_peer_device *const peer_device = first_peer_device(device); + struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL; + unsigned long bit; + sector_t sector; + const sector_t capacity = drbd_get_capacity(device->this_bdev); + int max_bio_size; + int number, rollback_i, size; + int align, requeue = 0; + int i = 0; + + if (unlikely(cancel)) + return 0; + + if (device->rs_total == 0) { + /* empty resync? */ + drbd_resync_finished(device); + return 0; + } + + if (!get_ldev(device)) { + /* Since we only need to access device->rsync a + get_ldev_if_state(device,D_FAILED) would be sufficient, but + to continue resync with a broken disk makes no sense at + all */ + drbd_err(device, "Disk broke down during resync!\n"); + return 0; + } + + max_bio_size = queue_max_hw_sectors(device->rq_queue) << 9; + number = drbd_rs_number_requests(device); + if (number <= 0) + goto requeue; + + for (i = 0; i < number; i++) { + /* Stop generating RS requests when half of the send buffer is filled, + * but notify TCP that we'd like to have more space. */ + mutex_lock(&connection->data.mutex); + if (connection->data.socket) { + struct sock *sk = connection->data.socket->sk; + int queued = sk->sk_wmem_queued; + int sndbuf = sk->sk_sndbuf; + if (queued > sndbuf / 2) { + requeue = 1; + if (sk->sk_socket) + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + } + } else + requeue = 1; + mutex_unlock(&connection->data.mutex); + if (requeue) + goto requeue; + +next_sector: + size = BM_BLOCK_SIZE; + bit = drbd_bm_find_next(device, device->bm_resync_fo); + + if (bit == DRBD_END_OF_BITMAP) { + device->bm_resync_fo = drbd_bm_bits(device); + put_ldev(device); + return 0; + } + + sector = BM_BIT_TO_SECT(bit); + + if (drbd_try_rs_begin_io(device, sector)) { + device->bm_resync_fo = bit; + goto requeue; + } + device->bm_resync_fo = bit + 1; + + if (unlikely(drbd_bm_test_bit(device, bit) == 0)) { + drbd_rs_complete_io(device, sector); + goto next_sector; + } + +#if DRBD_MAX_BIO_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. + */ + align = 1; + rollback_i = i; + while (i < number) { + if (size + BM_BLOCK_SIZE > max_bio_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(device, 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) + device->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 (device->use_csums) { + switch (read_for_csum(peer_device, sector, size)) { + case -EIO: /* Disk failure */ + put_ldev(device); + return -EIO; + case -EAGAIN: /* allocation failed, or ldev busy */ + drbd_rs_complete_io(device, sector); + device->bm_resync_fo = BM_SECT_TO_BIT(sector); + i = rollback_i; + goto requeue; + case 0: + /* everything ok */ + break; + default: + BUG(); + } + } else { + int err; + + inc_rs_pending(device); + err = drbd_send_drequest(peer_device, P_RS_DATA_REQUEST, + sector, size, ID_SYNCER); + if (err) { + drbd_err(device, "drbd_send_drequest() failed, aborting...\n"); + dec_rs_pending(device); + put_ldev(device); + return err; + } + } + } + + if (device->bm_resync_fo >= drbd_bm_bits(device)) { + /* 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" ... + */ + put_ldev(device); + return 0; + } + + requeue: + device->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9)); + mod_timer(&device->resync_timer, jiffies + SLEEP_TIME); + put_ldev(device); + return 0; +} + +static int make_ov_request(struct drbd_device *device, int cancel) +{ + int number, i, size; + sector_t sector; + const sector_t capacity = drbd_get_capacity(device->this_bdev); + bool stop_sector_reached = false; + + if (unlikely(cancel)) + return 1; + + number = drbd_rs_number_requests(device); + + sector = device->ov_position; + for (i = 0; i < number; i++) { + if (sector >= capacity) + return 1; + + /* We check for "finished" only in the reply path: + * w_e_end_ov_reply(). + * We need to send at least one request out. */ + stop_sector_reached = i > 0 + && verify_can_do_stop_sector(device) + && sector >= device->ov_stop_sector; + if (stop_sector_reached) + break; + + size = BM_BLOCK_SIZE; + + if (drbd_try_rs_begin_io(device, sector)) { + device->ov_position = sector; + goto requeue; + } + + if (sector + (size>>9) > capacity) + size = (capacity-sector)<<9; + + inc_rs_pending(device); + if (drbd_send_ov_request(first_peer_device(device), sector, size)) { + dec_rs_pending(device); + return 0; + } + sector += BM_SECT_PER_BIT; + } + device->ov_position = sector; + + requeue: + device->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9)); + if (i == 0 || !stop_sector_reached) + mod_timer(&device->resync_timer, jiffies + SLEEP_TIME); + return 1; +} + +int w_ov_finished(struct drbd_work *w, int cancel) +{ + struct drbd_device_work *dw = + container_of(w, struct drbd_device_work, w); + struct drbd_device *device = dw->device; + kfree(dw); + ov_out_of_sync_print(device); + drbd_resync_finished(device); + + return 0; +} + +static int w_resync_finished(struct drbd_work *w, int cancel) +{ + struct drbd_device_work *dw = + container_of(w, struct drbd_device_work, w); + struct drbd_device *device = dw->device; + kfree(dw); + + drbd_resync_finished(device); + + return 0; +} + +static void ping_peer(struct drbd_device *device) +{ + struct drbd_connection *connection = first_peer_device(device)->connection; + + clear_bit(GOT_PING_ACK, &connection->flags); + request_ping(connection); + wait_event(connection->ping_wait, + test_bit(GOT_PING_ACK, &connection->flags) || device->state.conn < C_CONNECTED); +} + +int drbd_resync_finished(struct drbd_device *device) +{ + unsigned long db, dt, dbdt; + unsigned long n_oos; + union drbd_state os, ns; + struct drbd_device_work *dw; + char *khelper_cmd = NULL; + int verify_done = 0; + + /* 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(device)) { + /* 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. */ + + schedule_timeout_interruptible(HZ / 10); + dw = kmalloc(sizeof(struct drbd_device_work), GFP_ATOMIC); + if (dw) { + dw->w.cb = w_resync_finished; + dw->device = device; + drbd_queue_work(&first_peer_device(device)->connection->sender_work, + &dw->w); + return 1; + } + drbd_err(device, "Warn failed to drbd_rs_del_all() and to kmalloc(dw).\n"); + } + + dt = (jiffies - device->rs_start - device->rs_paused) / HZ; + if (dt <= 0) + dt = 1; + + db = device->rs_total; + /* adjust for verify start and stop sectors, respective reached position */ + if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T) + db -= device->ov_left; + + dbdt = Bit2KB(db/dt); + device->rs_paused /= HZ; + + if (!get_ldev(device)) + goto out; + + ping_peer(device); + + spin_lock_irq(&device->resource->req_lock); + os = drbd_read_state(device); + + verify_done = (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T); + + /* 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; + + drbd_info(device, "%s done (total %lu sec; paused %lu sec; %lu K/sec)\n", + verify_done ? "Online verify" : "Resync", + dt + device->rs_paused, device->rs_paused, dbdt); + + n_oos = drbd_bm_total_weight(device); + + if (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) { + if (n_oos) { + drbd_alert(device, "Online verify found %lu %dk block out of sync!\n", + n_oos, Bit2KB(1)); + khelper_cmd = "out-of-sync"; + } + } else { + D_ASSERT(device, (n_oos - device->rs_failed) == 0); + + if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) + khelper_cmd = "after-resync-target"; + + if (device->use_csums && device->rs_total) { + const unsigned long s = device->rs_same_csum; + const unsigned long t = device->rs_total; + const int ratio = + (t == 0) ? 0 : + (t < 100000) ? ((s*100)/t) : (s/(t/100)); + drbd_info(device, "%u %% had equal checksums, eliminated: %luK; " + "transferred %luK total %luK\n", + ratio, + Bit2KB(device->rs_same_csum), + Bit2KB(device->rs_total - device->rs_same_csum), + Bit2KB(device->rs_total)); + } + } + + if (device->rs_failed) { + drbd_info(device, " %lu failed blocks\n", device->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 (device->p_uuid) { + int i; + for (i = UI_BITMAP ; i <= UI_HISTORY_END ; i++) + _drbd_uuid_set(device, i, device->p_uuid[i]); + drbd_uuid_set(device, UI_BITMAP, device->ldev->md.uuid[UI_CURRENT]); + _drbd_uuid_set(device, UI_CURRENT, device->p_uuid[UI_CURRENT]); + } else { + drbd_err(device, "device->p_uuid is NULL! BUG\n"); + } + } + + if (!(os.conn == C_VERIFY_S || os.conn == C_VERIFY_T)) { + /* for verify runs, we don't update uuids here, + * so there would be nothing to report. */ + drbd_uuid_set_bm(device, 0UL); + drbd_print_uuids(device, "updated UUIDs"); + if (device->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++) + device->p_uuid[i] = device->ldev->md.uuid[i]; + } + } + } + + _drbd_set_state(device, ns, CS_VERBOSE, NULL); +out_unlock: + spin_unlock_irq(&device->resource->req_lock); + put_ldev(device); +out: + device->rs_total = 0; + device->rs_failed = 0; + device->rs_paused = 0; + + /* reset start sector, if we reached end of device */ + if (verify_done && device->ov_left == 0) + device->ov_start_sector = 0; + + drbd_md_sync(device); + + if (khelper_cmd) + drbd_khelper(device, khelper_cmd); + + return 1; +} + +/* helper */ +static void move_to_net_ee_or_free(struct drbd_device *device, struct drbd_peer_request *peer_req) +{ + if (drbd_peer_req_has_active_page(peer_req)) { + /* This might happen if sendpage() has not finished */ + int i = (peer_req->i.size + PAGE_SIZE -1) >> PAGE_SHIFT; + atomic_add(i, &device->pp_in_use_by_net); + atomic_sub(i, &device->pp_in_use); + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&peer_req->w.list, &device->net_ee); + spin_unlock_irq(&device->resource->req_lock); + wake_up(&drbd_pp_wait); + } else + drbd_free_peer_req(device, peer_req); +} + +/** + * w_e_end_data_req() - Worker callback, to send a P_DATA_REPLY packet in response to a P_DATA_REQUEST + * @device: DRBD device. + * @w: work object. + * @cancel: The connection will be closed anyways + */ +int w_e_end_data_req(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + int err; + + if (unlikely(cancel)) { + drbd_free_peer_req(device, peer_req); + dec_unacked(device); + return 0; + } + + if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { + err = drbd_send_block(peer_device, P_DATA_REPLY, peer_req); + } else { + if (__ratelimit(&drbd_ratelimit_state)) + drbd_err(device, "Sending NegDReply. sector=%llus.\n", + (unsigned long long)peer_req->i.sector); + + err = drbd_send_ack(peer_device, P_NEG_DREPLY, peer_req); + } + + dec_unacked(device); + + move_to_net_ee_or_free(device, peer_req); + + if (unlikely(err)) + drbd_err(device, "drbd_send_block() failed\n"); + return err; +} + +/** + * w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUEST + * @w: work object. + * @cancel: The connection will be closed anyways + */ +int w_e_end_rsdata_req(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + int err; + + if (unlikely(cancel)) { + drbd_free_peer_req(device, peer_req); + dec_unacked(device); + return 0; + } + + if (get_ldev_if_state(device, D_FAILED)) { + drbd_rs_complete_io(device, peer_req->i.sector); + put_ldev(device); + } + + if (device->state.conn == C_AHEAD) { + err = drbd_send_ack(peer_device, P_RS_CANCEL, peer_req); + } else if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { + if (likely(device->state.pdsk >= D_INCONSISTENT)) { + inc_rs_pending(device); + err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req); + } else { + if (__ratelimit(&drbd_ratelimit_state)) + drbd_err(device, "Not sending RSDataReply, " + "partner DISKLESS!\n"); + err = 0; + } + } else { + if (__ratelimit(&drbd_ratelimit_state)) + drbd_err(device, "Sending NegRSDReply. sector %llus.\n", + (unsigned long long)peer_req->i.sector); + + err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req); + + /* update resync data with failure */ + drbd_rs_failed_io(device, peer_req->i.sector, peer_req->i.size); + } + + dec_unacked(device); + + move_to_net_ee_or_free(device, peer_req); + + if (unlikely(err)) + drbd_err(device, "drbd_send_block() failed\n"); + return err; +} + +int w_e_end_csum_rs_req(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + struct digest_info *di; + int digest_size; + void *digest = NULL; + int err, eq = 0; + + if (unlikely(cancel)) { + drbd_free_peer_req(device, peer_req); + dec_unacked(device); + return 0; + } + + if (get_ldev(device)) { + drbd_rs_complete_io(device, peer_req->i.sector); + put_ldev(device); + } + + di = peer_req->digest; + + if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { + /* quick hack to try to avoid a race against reconfiguration. + * a real fix would be much more involved, + * introducing more locking mechanisms */ + if (peer_device->connection->csums_tfm) { + digest_size = crypto_hash_digestsize(peer_device->connection->csums_tfm); + D_ASSERT(device, digest_size == di->digest_size); + digest = kmalloc(digest_size, GFP_NOIO); + } + if (digest) { + drbd_csum_ee(peer_device->connection->csums_tfm, peer_req, digest); + eq = !memcmp(digest, di->digest, digest_size); + kfree(digest); + } + + if (eq) { + drbd_set_in_sync(device, peer_req->i.sector, peer_req->i.size); + /* rs_same_csums unit is BM_BLOCK_SIZE */ + device->rs_same_csum += peer_req->i.size >> BM_BLOCK_SHIFT; + err = drbd_send_ack(peer_device, P_RS_IS_IN_SYNC, peer_req); + } else { + inc_rs_pending(device); + peer_req->block_id = ID_SYNCER; /* By setting block_id, digest pointer becomes invalid! */ + peer_req->flags &= ~EE_HAS_DIGEST; /* This peer request no longer has a digest pointer */ + kfree(di); + err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req); + } + } else { + err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req); + if (__ratelimit(&drbd_ratelimit_state)) + drbd_err(device, "Sending NegDReply. I guess it gets messy.\n"); + } + + dec_unacked(device); + move_to_net_ee_or_free(device, peer_req); + + if (unlikely(err)) + drbd_err(device, "drbd_send_block/ack() failed\n"); + return err; +} + +int w_e_end_ov_req(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + sector_t sector = peer_req->i.sector; + unsigned int size = peer_req->i.size; + int digest_size; + void *digest; + int err = 0; + + if (unlikely(cancel)) + goto out; + + digest_size = crypto_hash_digestsize(peer_device->connection->verify_tfm); + digest = kmalloc(digest_size, GFP_NOIO); + if (!digest) { + err = 1; /* terminate the connection in case the allocation failed */ + goto out; + } + + if (likely(!(peer_req->flags & EE_WAS_ERROR))) + drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest); + else + memset(digest, 0, digest_size); + + /* Free e and pages before send. + * In case we block on congestion, we could otherwise run into + * some distributed deadlock, if the other side blocks on + * congestion as well, because our receiver blocks in + * drbd_alloc_pages due to pp_in_use > max_buffers. */ + drbd_free_peer_req(device, peer_req); + peer_req = NULL; + inc_rs_pending(device); + err = drbd_send_drequest_csum(peer_device, sector, size, digest, digest_size, P_OV_REPLY); + if (err) + dec_rs_pending(device); + kfree(digest); + +out: + if (peer_req) + drbd_free_peer_req(device, peer_req); + dec_unacked(device); + return err; +} + +void drbd_ov_out_of_sync_found(struct drbd_device *device, sector_t sector, int size) +{ + if (device->ov_last_oos_start + device->ov_last_oos_size == sector) { + device->ov_last_oos_size += size>>9; + } else { + device->ov_last_oos_start = sector; + device->ov_last_oos_size = size>>9; + } + drbd_set_out_of_sync(device, sector, size); +} + +int w_e_end_ov_reply(struct drbd_work *w, int cancel) +{ + struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); + struct drbd_peer_device *peer_device = peer_req->peer_device; + struct drbd_device *device = peer_device->device; + struct digest_info *di; + void *digest; + sector_t sector = peer_req->i.sector; + unsigned int size = peer_req->i.size; + int digest_size; + int err, eq = 0; + bool stop_sector_reached = false; + + if (unlikely(cancel)) { + drbd_free_peer_req(device, peer_req); + dec_unacked(device); + return 0; + } + + /* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all + * the resync lru has been cleaned up already */ + if (get_ldev(device)) { + drbd_rs_complete_io(device, peer_req->i.sector); + put_ldev(device); + } + + di = peer_req->digest; + + if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { + digest_size = crypto_hash_digestsize(peer_device->connection->verify_tfm); + digest = kmalloc(digest_size, GFP_NOIO); + if (digest) { + drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest); + + D_ASSERT(device, digest_size == di->digest_size); + eq = !memcmp(digest, di->digest, digest_size); + kfree(digest); + } + } + + /* Free peer_req and pages before send. + * In case we block on congestion, we could otherwise run into + * some distributed deadlock, if the other side blocks on + * congestion as well, because our receiver blocks in + * drbd_alloc_pages due to pp_in_use > max_buffers. */ + drbd_free_peer_req(device, peer_req); + if (!eq) + drbd_ov_out_of_sync_found(device, sector, size); + else + ov_out_of_sync_print(device); + + err = drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size, + eq ? ID_IN_SYNC : ID_OUT_OF_SYNC); + + dec_unacked(device); + + --device->ov_left; + + /* let's advance progress step marks only for every other megabyte */ + if ((device->ov_left & 0x200) == 0x200) + drbd_advance_rs_marks(device, device->ov_left); + + stop_sector_reached = verify_can_do_stop_sector(device) && + (sector + (size>>9)) >= device->ov_stop_sector; + + if (device->ov_left == 0 || stop_sector_reached) { + ov_out_of_sync_print(device); + drbd_resync_finished(device); + } + + return err; +} + +/* FIXME + * We need to track the number of pending barrier acks, + * and to be able to wait for them. + * See also comment in drbd_adm_attach before drbd_suspend_io. + */ +static int drbd_send_barrier(struct drbd_connection *connection) +{ + struct p_barrier *p; + struct drbd_socket *sock; + + sock = &connection->data; + p = conn_prepare_command(connection, sock); + if (!p) + return -EIO; + p->barrier = connection->send.current_epoch_nr; + p->pad = 0; + connection->send.current_epoch_writes = 0; + + return conn_send_command(connection, sock, P_BARRIER, sizeof(*p), NULL, 0); +} + +int w_send_write_hint(struct drbd_work *w, int cancel) +{ + struct drbd_device *device = + container_of(w, struct drbd_device, unplug_work); + struct drbd_socket *sock; + + if (cancel) + return 0; + sock = &first_peer_device(device)->connection->data; + if (!drbd_prepare_command(first_peer_device(device), sock)) + return -EIO; + return drbd_send_command(first_peer_device(device), sock, P_UNPLUG_REMOTE, 0, NULL, 0); +} + +static void re_init_if_first_write(struct drbd_connection *connection, unsigned int epoch) +{ + if (!connection->send.seen_any_write_yet) { + connection->send.seen_any_write_yet = true; + connection->send.current_epoch_nr = epoch; + connection->send.current_epoch_writes = 0; + } +} + +static void maybe_send_barrier(struct drbd_connection *connection, unsigned int epoch) +{ + /* re-init if first write on this connection */ + if (!connection->send.seen_any_write_yet) + return; + if (connection->send.current_epoch_nr != epoch) { + if (connection->send.current_epoch_writes) + drbd_send_barrier(connection); + connection->send.current_epoch_nr = epoch; + } +} + +int w_send_out_of_sync(struct drbd_work *w, int cancel) +{ + struct drbd_request *req = container_of(w, struct drbd_request, w); + struct drbd_device *device = req->device; + struct drbd_peer_device *const peer_device = first_peer_device(device); + struct drbd_connection *const connection = peer_device->connection; + int err; + + if (unlikely(cancel)) { + req_mod(req, SEND_CANCELED); + return 0; + } + req->pre_send_jif = jiffies; + + /* this time, no connection->send.current_epoch_writes++; + * If it was sent, it was the closing barrier for the last + * replicated epoch, before we went into AHEAD mode. + * No more barriers will be sent, until we leave AHEAD mode again. */ + maybe_send_barrier(connection, req->epoch); + + err = drbd_send_out_of_sync(peer_device, req); + req_mod(req, OOS_HANDED_TO_NETWORK); + + return err; +} + +/** + * w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request + * @w: work object. + * @cancel: The connection will be closed anyways + */ +int w_send_dblock(struct drbd_work *w, int cancel) +{ + struct drbd_request *req = container_of(w, struct drbd_request, w); + struct drbd_device *device = req->device; + struct drbd_peer_device *const peer_device = first_peer_device(device); + struct drbd_connection *connection = peer_device->connection; + int err; + + if (unlikely(cancel)) { + req_mod(req, SEND_CANCELED); + return 0; + } + req->pre_send_jif = jiffies; + + re_init_if_first_write(connection, req->epoch); + maybe_send_barrier(connection, req->epoch); + connection->send.current_epoch_writes++; + + err = drbd_send_dblock(peer_device, req); + req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK); + + return err; +} + +/** + * w_send_read_req() - Worker callback to send a read request (P_DATA_REQUEST) packet + * @w: work object. + * @cancel: The connection will be closed anyways + */ +int w_send_read_req(struct drbd_work *w, int cancel) +{ + struct drbd_request *req = container_of(w, struct drbd_request, w); + struct drbd_device *device = req->device; + struct drbd_peer_device *const peer_device = first_peer_device(device); + struct drbd_connection *connection = peer_device->connection; + int err; + + if (unlikely(cancel)) { + req_mod(req, SEND_CANCELED); + return 0; + } + req->pre_send_jif = jiffies; + + /* Even read requests may close a write epoch, + * if there was any yet. */ + maybe_send_barrier(connection, req->epoch); + + err = drbd_send_drequest(peer_device, P_DATA_REQUEST, req->i.sector, req->i.size, + (unsigned long)req); + + req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK); + + return err; +} + +int w_restart_disk_io(struct drbd_work *w, int cancel) +{ + struct drbd_request *req = container_of(w, struct drbd_request, w); + struct drbd_device *device = req->device; + + if (bio_data_dir(req->master_bio) == WRITE && req->rq_state & RQ_IN_ACT_LOG) + drbd_al_begin_io(device, &req->i); + + drbd_req_make_private_bio(req, req->master_bio); + req->private_bio->bi_bdev = device->ldev->backing_bdev; + generic_make_request(req->private_bio); + + return 0; +} + +static int _drbd_may_sync_now(struct drbd_device *device) +{ + struct drbd_device *odev = device; + int resync_after; + + while (1) { + if (!odev->ldev || odev->state.disk == D_DISKLESS) + return 1; + rcu_read_lock(); + resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after; + rcu_read_unlock(); + if (resync_after == -1) + return 1; + odev = minor_to_device(resync_after); + 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 + * @device: DRBD device. + * + * Called from process context only (admin command and after_state_ch). + */ +static int _drbd_pause_after(struct drbd_device *device) +{ + struct drbd_device *odev; + int i, rv = 0; + + rcu_read_lock(); + idr_for_each_entry(&drbd_devices, odev, i) { + 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); + } + rcu_read_unlock(); + + return rv; +} + +/** + * _drbd_resume_next() - Resume resync on all devices that may resync now + * @device: DRBD device. + * + * Called from process context only (admin command and worker). + */ +static int _drbd_resume_next(struct drbd_device *device) +{ + struct drbd_device *odev; + int i, rv = 0; + + rcu_read_lock(); + idr_for_each_entry(&drbd_devices, odev, i) { + 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) ; + } + } + rcu_read_unlock(); + return rv; +} + +void resume_next_sg(struct drbd_device *device) +{ + write_lock_irq(&global_state_lock); + _drbd_resume_next(device); + write_unlock_irq(&global_state_lock); +} + +void suspend_other_sg(struct drbd_device *device) +{ + write_lock_irq(&global_state_lock); + _drbd_pause_after(device); + write_unlock_irq(&global_state_lock); +} + +/* caller must hold global_state_lock */ +enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor) +{ + struct drbd_device *odev; + int resync_after; + + if (o_minor == -1) + return NO_ERROR; + if (o_minor < -1 || o_minor > MINORMASK) + return ERR_RESYNC_AFTER; + + /* check for loops */ + odev = minor_to_device(o_minor); + while (1) { + if (odev == device) + return ERR_RESYNC_AFTER_CYCLE; + + /* You are free to depend on diskless, non-existing, + * or not yet/no longer existing minors. + * We only reject dependency loops. + * We cannot follow the dependency chain beyond a detached or + * missing minor. + */ + if (!odev || !odev->ldev || odev->state.disk == D_DISKLESS) + return NO_ERROR; + + rcu_read_lock(); + resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after; + rcu_read_unlock(); + /* dependency chain ends here, no cycles. */ + if (resync_after == -1) + return NO_ERROR; + + /* follow the dependency chain */ + odev = minor_to_device(resync_after); + } +} + +/* caller must hold global_state_lock */ +void drbd_resync_after_changed(struct drbd_device *device) +{ + int changes; + + do { + changes = _drbd_pause_after(device); + changes |= _drbd_resume_next(device); + } while (changes); +} + +void drbd_rs_controller_reset(struct drbd_device *device) +{ + struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk; + struct fifo_buffer *plan; + + atomic_set(&device->rs_sect_in, 0); + atomic_set(&device->rs_sect_ev, 0); + device->rs_in_flight = 0; + device->rs_last_events = + (int)part_stat_read(&disk->part0, sectors[0]) + + (int)part_stat_read(&disk->part0, sectors[1]); + + /* Updating the RCU protected object in place is necessary since + this function gets called from atomic context. + It is valid since all other updates also lead to an completely + empty fifo */ + rcu_read_lock(); + plan = rcu_dereference(device->rs_plan_s); + plan->total = 0; + fifo_set(plan, 0); + rcu_read_unlock(); +} + +void start_resync_timer_fn(unsigned long data) +{ + struct drbd_device *device = (struct drbd_device *) data; + drbd_device_post_work(device, RS_START); +} + +static void do_start_resync(struct drbd_device *device) +{ + if (atomic_read(&device->unacked_cnt) || atomic_read(&device->rs_pending_cnt)) { + drbd_warn(device, "postponing start_resync ...\n"); + device->start_resync_timer.expires = jiffies + HZ/10; + add_timer(&device->start_resync_timer); + return; + } + + drbd_start_resync(device, C_SYNC_SOURCE); + clear_bit(AHEAD_TO_SYNC_SOURCE, &device->flags); +} + +static bool use_checksum_based_resync(struct drbd_connection *connection, struct drbd_device *device) +{ + bool csums_after_crash_only; + rcu_read_lock(); + csums_after_crash_only = rcu_dereference(connection->net_conf)->csums_after_crash_only; + rcu_read_unlock(); + return connection->agreed_pro_version >= 89 && /* supported? */ + connection->csums_tfm && /* configured? */ + (csums_after_crash_only == 0 /* use for each resync? */ + || test_bit(CRASHED_PRIMARY, &device->flags)); /* or only after Primary crash? */ +} + +/** + * drbd_start_resync() - Start the resync process + * @device: 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_device *device, enum drbd_conns side) +{ + struct drbd_peer_device *peer_device = first_peer_device(device); + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + union drbd_state ns; + int r; + + if (device->state.conn >= C_SYNC_SOURCE && device->state.conn < C_AHEAD) { + drbd_err(device, "Resync already running!\n"); + return; + } + + if (!test_bit(B_RS_H_DONE, &device->flags)) { + 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(device, "before-resync-target"); + r = (r >> 8) & 0xff; + if (r > 0) { + drbd_info(device, "before-resync-target handler returned %d, " + "dropping connection.\n", r); + conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); + return; + } + } else /* C_SYNC_SOURCE */ { + r = drbd_khelper(device, "before-resync-source"); + r = (r >> 8) & 0xff; + if (r > 0) { + if (r == 3) { + drbd_info(device, "before-resync-source handler returned %d, " + "ignoring. Old userland tools?", r); + } else { + drbd_info(device, "before-resync-source handler returned %d, " + "dropping connection.\n", r); + conn_request_state(connection, + NS(conn, C_DISCONNECTING), CS_HARD); + return; + } + } + } + } + + if (current == connection->worker.task) { + /* The worker should not sleep waiting for state_mutex, + that can take long */ + if (!mutex_trylock(device->state_mutex)) { + set_bit(B_RS_H_DONE, &device->flags); + device->start_resync_timer.expires = jiffies + HZ/5; + add_timer(&device->start_resync_timer); + return; + } + } else { + mutex_lock(device->state_mutex); + } + clear_bit(B_RS_H_DONE, &device->flags); + + /* req_lock: serialize with drbd_send_and_submit() and others + * global_state_lock: for stable sync-after dependencies */ + spin_lock_irq(&device->resource->req_lock); + write_lock(&global_state_lock); + /* Did some connection breakage or IO error race with us? */ + if (device->state.conn < C_CONNECTED + || !get_ldev_if_state(device, D_NEGOTIATING)) { + write_unlock(&global_state_lock); + spin_unlock_irq(&device->resource->req_lock); + mutex_unlock(device->state_mutex); + return; + } + + ns = drbd_read_state(device); + + ns.aftr_isp = !_drbd_may_sync_now(device); + + 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(device, ns, CS_VERBOSE, NULL); + ns = drbd_read_state(device); + + if (ns.conn < C_CONNECTED) + r = SS_UNKNOWN_ERROR; + + if (r == SS_SUCCESS) { + unsigned long tw = drbd_bm_total_weight(device); + unsigned long now = jiffies; + int i; + + device->rs_failed = 0; + device->rs_paused = 0; + device->rs_same_csum = 0; + device->rs_last_sect_ev = 0; + device->rs_total = tw; + device->rs_start = now; + for (i = 0; i < DRBD_SYNC_MARKS; i++) { + device->rs_mark_left[i] = tw; + device->rs_mark_time[i] = now; + } + _drbd_pause_after(device); + /* Forget potentially stale cached per resync extent bit-counts. + * Open coded drbd_rs_cancel_all(device), we already have IRQs + * disabled, and know the disk state is ok. */ + spin_lock(&device->al_lock); + lc_reset(device->resync); + device->resync_locked = 0; + device->resync_wenr = LC_FREE; + spin_unlock(&device->al_lock); + } + write_unlock(&global_state_lock); + spin_unlock_irq(&device->resource->req_lock); + + if (r == SS_SUCCESS) { + wake_up(&device->al_wait); /* for lc_reset() above */ + /* reset rs_last_bcast when a resync or verify is started, + * to deal with potential jiffies wrap. */ + device->rs_last_bcast = jiffies - HZ; + + drbd_info(device, "Began resync as %s (will sync %lu KB [%lu bits set]).\n", + drbd_conn_str(ns.conn), + (unsigned long) device->rs_total << (BM_BLOCK_SHIFT-10), + (unsigned long) device->rs_total); + if (side == C_SYNC_TARGET) { + device->bm_resync_fo = 0; + device->use_csums = use_checksum_based_resync(connection, device); + } else { + device->use_csums = 0; + } + + /* Since protocol 96, we must serialize drbd_gen_and_send_sync_uuid + * with w_send_oos, or the sync target will get confused as to + * how much bits to resync. We cannot do that always, because for an + * empty resync and protocol < 95, we need to do it here, as we call + * drbd_resync_finished from here in that case. + * We drbd_gen_and_send_sync_uuid here for protocol < 96, + * and from after_state_ch otherwise. */ + if (side == C_SYNC_SOURCE && connection->agreed_pro_version < 96) + drbd_gen_and_send_sync_uuid(peer_device); + + if (connection->agreed_pro_version < 95 && device->rs_total == 0) { + /* This still has a race (about when exactly the peers + * detect connection loss) that can lead to a full sync + * on next handshake. In 8.3.9 we fixed this with explicit + * resync-finished notifications, but the fix + * introduces a protocol change. Sleeping for some + * time longer than the ping interval + timeout on the + * SyncSource, to give the SyncTarget the chance to + * detect connection loss, then waiting for a ping + * response (implicit in drbd_resync_finished) reduces + * the race considerably, but does not solve it. */ + if (side == C_SYNC_SOURCE) { + struct net_conf *nc; + int timeo; + + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + timeo = nc->ping_int * HZ + nc->ping_timeo * HZ / 9; + rcu_read_unlock(); + schedule_timeout_interruptible(timeo); + } + drbd_resync_finished(device); + } + + drbd_rs_controller_reset(device); + /* ns.conn may already be != device->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(&device->resync_timer, jiffies); + + drbd_md_sync(device); + } + put_ldev(device); + mutex_unlock(device->state_mutex); +} + +static void update_on_disk_bitmap(struct drbd_device *device, bool resync_done) +{ + struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, }; + device->rs_last_bcast = jiffies; + + if (!get_ldev(device)) + return; + + drbd_bm_write_lazy(device, 0); + if (resync_done && is_sync_state(device->state.conn)) + drbd_resync_finished(device); + + drbd_bcast_event(device, &sib); + /* update timestamp, in case it took a while to write out stuff */ + device->rs_last_bcast = jiffies; + put_ldev(device); +} + +static void drbd_ldev_destroy(struct drbd_device *device) +{ + lc_destroy(device->resync); + device->resync = NULL; + lc_destroy(device->act_log); + device->act_log = NULL; + + __acquire(local); + drbd_free_ldev(device->ldev); + device->ldev = NULL; + __release(local); + + clear_bit(GOING_DISKLESS, &device->flags); + wake_up(&device->misc_wait); +} + +static void go_diskless(struct drbd_device *device) +{ + D_ASSERT(device, device->state.disk == D_FAILED); + /* we cannot assert local_cnt == 0 here, as get_ldev_if_state will + * inc/dec it frequently. Once we are D_DISKLESS, no one will touch + * the protected members anymore, though, so once put_ldev reaches zero + * again, it will be safe to free them. */ + + /* Try to write changed bitmap pages, read errors may have just + * set some bits outside the area covered by the activity log. + * + * If we have an IO error during the bitmap writeout, + * we will want a full sync next time, just in case. + * (Do we want a specific meta data flag for this?) + * + * If that does not make it to stable storage either, + * we cannot do anything about that anymore. + * + * We still need to check if both bitmap and ldev are present, we may + * end up here after a failed attach, before ldev was even assigned. + */ + if (device->bitmap && device->ldev) { + /* An interrupted resync or similar is allowed to recounts bits + * while we detach. + * Any modifications would not be expected anymore, though. + */ + if (drbd_bitmap_io_from_worker(device, drbd_bm_write, + "detach", BM_LOCKED_TEST_ALLOWED)) { + if (test_bit(WAS_READ_ERROR, &device->flags)) { + drbd_md_set_flag(device, MDF_FULL_SYNC); + drbd_md_sync(device); + } + } + } + + drbd_force_state(device, NS(disk, D_DISKLESS)); +} + +static int do_md_sync(struct drbd_device *device) +{ + drbd_warn(device, "md_sync_timer expired! Worker calls drbd_md_sync().\n"); + drbd_md_sync(device); + return 0; +} + +/* only called from drbd_worker thread, no locking */ +void __update_timing_details( + struct drbd_thread_timing_details *tdp, + unsigned int *cb_nr, + void *cb, + const char *fn, const unsigned int line) +{ + unsigned int i = *cb_nr % DRBD_THREAD_DETAILS_HIST; + struct drbd_thread_timing_details *td = tdp + i; + + td->start_jif = jiffies; + td->cb_addr = cb; + td->caller_fn = fn; + td->line = line; + td->cb_nr = *cb_nr; + + i = (i+1) % DRBD_THREAD_DETAILS_HIST; + td = tdp + i; + memset(td, 0, sizeof(*td)); + + ++(*cb_nr); +} + +static void do_device_work(struct drbd_device *device, const unsigned long todo) +{ + if (test_bit(MD_SYNC, &todo)) + do_md_sync(device); + if (test_bit(RS_DONE, &todo) || + test_bit(RS_PROGRESS, &todo)) + update_on_disk_bitmap(device, test_bit(RS_DONE, &todo)); + if (test_bit(GO_DISKLESS, &todo)) + go_diskless(device); + if (test_bit(DESTROY_DISK, &todo)) + drbd_ldev_destroy(device); + if (test_bit(RS_START, &todo)) + do_start_resync(device); +} + +#define DRBD_DEVICE_WORK_MASK \ + ((1UL << GO_DISKLESS) \ + |(1UL << DESTROY_DISK) \ + |(1UL << MD_SYNC) \ + |(1UL << RS_START) \ + |(1UL << RS_PROGRESS) \ + |(1UL << RS_DONE) \ + ) + +static unsigned long get_work_bits(unsigned long *flags) +{ + unsigned long old, new; + do { + old = *flags; + new = old & ~DRBD_DEVICE_WORK_MASK; + } while (cmpxchg(flags, old, new) != old); + return old & DRBD_DEVICE_WORK_MASK; +} + +static void do_unqueued_work(struct drbd_connection *connection) +{ + struct drbd_peer_device *peer_device; + int vnr; + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + unsigned long todo = get_work_bits(&device->flags); + if (!todo) + continue; + + kref_get(&device->kref); + rcu_read_unlock(); + do_device_work(device, todo); + kref_put(&device->kref, drbd_destroy_device); + rcu_read_lock(); + } + rcu_read_unlock(); +} + +static bool dequeue_work_batch(struct drbd_work_queue *queue, struct list_head *work_list) +{ + spin_lock_irq(&queue->q_lock); + list_splice_tail_init(&queue->q, work_list); + spin_unlock_irq(&queue->q_lock); + return !list_empty(work_list); +} + +static void wait_for_work(struct drbd_connection *connection, struct list_head *work_list) +{ + DEFINE_WAIT(wait); + struct net_conf *nc; + int uncork, cork; + + dequeue_work_batch(&connection->sender_work, work_list); + if (!list_empty(work_list)) + return; + + /* Still nothing to do? + * Maybe we still need to close the current epoch, + * even if no new requests are queued yet. + * + * Also, poke TCP, just in case. + * Then wait for new work (or signal). */ + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + uncork = nc ? nc->tcp_cork : 0; + rcu_read_unlock(); + if (uncork) { + mutex_lock(&connection->data.mutex); + if (connection->data.socket) + drbd_tcp_uncork(connection->data.socket); + mutex_unlock(&connection->data.mutex); + } + + for (;;) { + int send_barrier; + prepare_to_wait(&connection->sender_work.q_wait, &wait, TASK_INTERRUPTIBLE); + spin_lock_irq(&connection->resource->req_lock); + spin_lock(&connection->sender_work.q_lock); /* FIXME get rid of this one? */ + if (!list_empty(&connection->sender_work.q)) + list_splice_tail_init(&connection->sender_work.q, work_list); + spin_unlock(&connection->sender_work.q_lock); /* FIXME get rid of this one? */ + if (!list_empty(work_list) || signal_pending(current)) { + spin_unlock_irq(&connection->resource->req_lock); + break; + } + + /* We found nothing new to do, no to-be-communicated request, + * no other work item. We may still need to close the last + * epoch. Next incoming request epoch will be connection -> + * current transfer log epoch number. If that is different + * from the epoch of the last request we communicated, it is + * safe to send the epoch separating barrier now. + */ + send_barrier = + atomic_read(&connection->current_tle_nr) != + connection->send.current_epoch_nr; + spin_unlock_irq(&connection->resource->req_lock); + + if (send_barrier) + maybe_send_barrier(connection, + connection->send.current_epoch_nr + 1); + + if (test_bit(DEVICE_WORK_PENDING, &connection->flags)) + break; + + /* drbd_send() may have called flush_signals() */ + if (get_t_state(&connection->worker) != RUNNING) + break; + + schedule(); + /* may be woken up for other things but new work, too, + * e.g. if the current epoch got closed. + * In which case we send the barrier above. */ + } + finish_wait(&connection->sender_work.q_wait, &wait); + + /* someone may have changed the config while we have been waiting above. */ + rcu_read_lock(); + nc = rcu_dereference(connection->net_conf); + cork = nc ? nc->tcp_cork : 0; + rcu_read_unlock(); + mutex_lock(&connection->data.mutex); + if (connection->data.socket) { + if (cork) + drbd_tcp_cork(connection->data.socket); + else if (!uncork) + drbd_tcp_uncork(connection->data.socket); + } + mutex_unlock(&connection->data.mutex); +} + +int drbd_worker(struct drbd_thread *thi) +{ + struct drbd_connection *connection = thi->connection; + struct drbd_work *w = NULL; + struct drbd_peer_device *peer_device; + LIST_HEAD(work_list); + int vnr; + + while (get_t_state(thi) == RUNNING) { + drbd_thread_current_set_cpu(thi); + + if (list_empty(&work_list)) { + update_worker_timing_details(connection, wait_for_work); + wait_for_work(connection, &work_list); + } + + if (test_and_clear_bit(DEVICE_WORK_PENDING, &connection->flags)) { + update_worker_timing_details(connection, do_unqueued_work); + do_unqueued_work(connection); + } + + if (signal_pending(current)) { + flush_signals(current); + if (get_t_state(thi) == RUNNING) { + drbd_warn(connection, "Worker got an unexpected signal\n"); + continue; + } + break; + } + + if (get_t_state(thi) != RUNNING) + break; + + if (!list_empty(&work_list)) { + w = list_first_entry(&work_list, struct drbd_work, list); + list_del_init(&w->list); + update_worker_timing_details(connection, w->cb); + if (w->cb(w, connection->cstate < C_WF_REPORT_PARAMS) == 0) + continue; + if (connection->cstate >= C_WF_REPORT_PARAMS) + conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD); + } + } + + do { + if (test_and_clear_bit(DEVICE_WORK_PENDING, &connection->flags)) { + update_worker_timing_details(connection, do_unqueued_work); + do_unqueued_work(connection); + } + if (!list_empty(&work_list)) { + w = list_first_entry(&work_list, struct drbd_work, list); + list_del_init(&w->list); + update_worker_timing_details(connection, w->cb); + w->cb(w, 1); + } else + dequeue_work_batch(&connection->sender_work, &work_list); + } while (!list_empty(&work_list) || test_bit(DEVICE_WORK_PENDING, &connection->flags)); + + rcu_read_lock(); + idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { + struct drbd_device *device = peer_device->device; + D_ASSERT(device, device->state.disk == D_DISKLESS && device->state.conn == C_STANDALONE); + kref_get(&device->kref); + rcu_read_unlock(); + drbd_device_cleanup(device); + kref_put(&device->kref, drbd_destroy_device); + rcu_read_lock(); + } + rcu_read_unlock(); + + return 0; +} |