diff options
Diffstat (limited to 'drivers/block/drbd/drbd_actlog.c')
| -rw-r--r-- | drivers/block/drbd/drbd_actlog.c | 1261 |
1 files changed, 1261 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c new file mode 100644 index 00000000..cf0e63dd --- /dev/null +++ b/drivers/block/drbd/drbd_actlog.c @@ -0,0 +1,1261 @@ +/* + drbd_actlog.c + + This file is part of DRBD by Philipp Reisner and Lars Ellenberg. + + Copyright (C) 2003-2008, LINBIT Information Technologies GmbH. + Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>. + Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. + + drbd is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + drbd is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with drbd; see the file COPYING. If not, write to + the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + + */ + +#include <linux/slab.h> +#include <linux/drbd.h> +#include "drbd_int.h" +#include "drbd_wrappers.h" + +/* We maintain a trivial checksum in our on disk activity log. + * With that we can ensure correct operation even when the storage + * device might do a partial (last) sector write while losing power. + */ +struct __packed al_transaction { + u32 magic; + u32 tr_number; + struct __packed { + u32 pos; + u32 extent; } updates[1 + AL_EXTENTS_PT]; + u32 xor_sum; +}; + +struct update_odbm_work { + struct drbd_work w; + unsigned int enr; +}; + +struct update_al_work { + struct drbd_work w; + struct lc_element *al_ext; + struct completion event; + unsigned int enr; + /* if old_enr != LC_FREE, write corresponding bitmap sector, too */ + unsigned int old_enr; +}; + +struct drbd_atodb_wait { + atomic_t count; + struct completion io_done; + struct drbd_conf *mdev; + int error; +}; + + +int w_al_write_transaction(struct drbd_conf *, struct drbd_work *, int); + +static int _drbd_md_sync_page_io(struct drbd_conf *mdev, + struct drbd_backing_dev *bdev, + struct page *page, sector_t sector, + int rw, int size) +{ + struct bio *bio; + struct drbd_md_io md_io; + int ok; + + md_io.mdev = mdev; + init_completion(&md_io.event); + md_io.error = 0; + + if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags)) + rw |= REQ_FUA | REQ_FLUSH; + rw |= REQ_SYNC; + + bio = bio_alloc(GFP_NOIO, 1); + bio->bi_bdev = bdev->md_bdev; + bio->bi_sector = sector; + ok = (bio_add_page(bio, page, size, 0) == size); + if (!ok) + goto out; + bio->bi_private = &md_io; + bio->bi_end_io = drbd_md_io_complete; + bio->bi_rw = rw; + + if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) + bio_endio(bio, -EIO); + else + submit_bio(rw, bio); + wait_for_completion(&md_io.event); + ok = bio_flagged(bio, BIO_UPTODATE) && md_io.error == 0; + + out: + bio_put(bio); + return ok; +} + +int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, + sector_t sector, int rw) +{ + int logical_block_size, mask, ok; + int offset = 0; + struct page *iop = mdev->md_io_page; + + D_ASSERT(mutex_is_locked(&mdev->md_io_mutex)); + + BUG_ON(!bdev->md_bdev); + + logical_block_size = bdev_logical_block_size(bdev->md_bdev); + if (logical_block_size == 0) + logical_block_size = MD_SECTOR_SIZE; + + /* in case logical_block_size != 512 [ s390 only? ] */ + if (logical_block_size != MD_SECTOR_SIZE) { + mask = (logical_block_size / MD_SECTOR_SIZE) - 1; + D_ASSERT(mask == 1 || mask == 3 || mask == 7); + D_ASSERT(logical_block_size == (mask+1) * MD_SECTOR_SIZE); + offset = sector & mask; + sector = sector & ~mask; + iop = mdev->md_io_tmpp; + + if (rw & WRITE) { + /* these are GFP_KERNEL pages, pre-allocated + * on device initialization */ + void *p = page_address(mdev->md_io_page); + void *hp = page_address(mdev->md_io_tmpp); + + ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, + READ, logical_block_size); + + if (unlikely(!ok)) { + dev_err(DEV, "drbd_md_sync_page_io(,%llus," + "READ [logical_block_size!=512]) failed!\n", + (unsigned long long)sector); + return 0; + } + + memcpy(hp + offset*MD_SECTOR_SIZE, p, MD_SECTOR_SIZE); + } + } + + if (sector < drbd_md_first_sector(bdev) || + sector > drbd_md_last_sector(bdev)) + dev_alert(DEV, "%s [%d]:%s(,%llus,%s) out of range md access!\n", + current->comm, current->pid, __func__, + (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ"); + + ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, logical_block_size); + if (unlikely(!ok)) { + dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed!\n", + (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ"); + return 0; + } + + if (logical_block_size != MD_SECTOR_SIZE && !(rw & WRITE)) { + void *p = page_address(mdev->md_io_page); + void *hp = page_address(mdev->md_io_tmpp); + + memcpy(p, hp + offset*MD_SECTOR_SIZE, MD_SECTOR_SIZE); + } + + return ok; +} + +static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr) +{ + struct lc_element *al_ext; + struct lc_element *tmp; + unsigned long al_flags = 0; + int wake; + + spin_lock_irq(&mdev->al_lock); + tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT); + if (unlikely(tmp != NULL)) { + struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); + if (test_bit(BME_NO_WRITES, &bm_ext->flags)) { + wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags); + spin_unlock_irq(&mdev->al_lock); + if (wake) + wake_up(&mdev->al_wait); + return NULL; + } + } + al_ext = lc_get(mdev->act_log, enr); + al_flags = mdev->act_log->flags; + spin_unlock_irq(&mdev->al_lock); + + /* + if (!al_ext) { + if (al_flags & LC_STARVING) + dev_warn(DEV, "Have to wait for LRU element (AL too small?)\n"); + if (al_flags & LC_DIRTY) + dev_warn(DEV, "Ongoing AL update (AL device too slow?)\n"); + } + */ + + return al_ext; +} + +void drbd_al_begin_io(struct drbd_conf *mdev, sector_t sector) +{ + unsigned int enr = (sector >> (AL_EXTENT_SHIFT-9)); + struct lc_element *al_ext; + struct update_al_work al_work; + + D_ASSERT(atomic_read(&mdev->local_cnt) > 0); + + wait_event(mdev->al_wait, (al_ext = _al_get(mdev, enr))); + + if (al_ext->lc_number != enr) { + /* drbd_al_write_transaction(mdev,al_ext,enr); + * recurses into generic_make_request(), which + * disallows recursion, bios being serialized on the + * current->bio_tail list now. + * we have to delegate updates to the activity log + * to the worker thread. */ + init_completion(&al_work.event); + al_work.al_ext = al_ext; + al_work.enr = enr; + al_work.old_enr = al_ext->lc_number; + al_work.w.cb = w_al_write_transaction; + drbd_queue_work_front(&mdev->data.work, &al_work.w); + wait_for_completion(&al_work.event); + + mdev->al_writ_cnt++; + + spin_lock_irq(&mdev->al_lock); + lc_changed(mdev->act_log, al_ext); + spin_unlock_irq(&mdev->al_lock); + wake_up(&mdev->al_wait); + } +} + +void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector) +{ + unsigned int enr = (sector >> (AL_EXTENT_SHIFT-9)); + struct lc_element *extent; + unsigned long flags; + + spin_lock_irqsave(&mdev->al_lock, flags); + + extent = lc_find(mdev->act_log, enr); + + if (!extent) { + spin_unlock_irqrestore(&mdev->al_lock, flags); + dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr); + return; + } + + if (lc_put(mdev->act_log, extent) == 0) + wake_up(&mdev->al_wait); + + spin_unlock_irqrestore(&mdev->al_lock, flags); +} + +#if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT) +/* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT + * are still coupled, or assume too much about their relation. + * Code below will not work if this is violated. + * Will be cleaned up with some followup patch. + */ +# error FIXME +#endif + +static unsigned int al_extent_to_bm_page(unsigned int al_enr) +{ + return al_enr >> + /* bit to page */ + ((PAGE_SHIFT + 3) - + /* al extent number to bit */ + (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)); +} + +static unsigned int rs_extent_to_bm_page(unsigned int rs_enr) +{ + return rs_enr >> + /* bit to page */ + ((PAGE_SHIFT + 3) - + /* al extent number to bit */ + (BM_EXT_SHIFT - BM_BLOCK_SHIFT)); +} + +int +w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused) +{ + struct update_al_work *aw = container_of(w, struct update_al_work, w); + struct lc_element *updated = aw->al_ext; + const unsigned int new_enr = aw->enr; + const unsigned int evicted = aw->old_enr; + struct al_transaction *buffer; + sector_t sector; + int i, n, mx; + unsigned int extent_nr; + u32 xor_sum = 0; + + if (!get_ldev(mdev)) { + dev_err(DEV, + "disk is %s, cannot start al transaction (-%d +%d)\n", + drbd_disk_str(mdev->state.disk), evicted, new_enr); + complete(&((struct update_al_work *)w)->event); + return 1; + } + /* do we have to do a bitmap write, first? + * TODO reduce maximum latency: + * submit both bios, then wait for both, + * instead of doing two synchronous sector writes. + * For now, we must not write the transaction, + * if we cannot write out the bitmap of the evicted extent. */ + if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE) + drbd_bm_write_page(mdev, al_extent_to_bm_page(evicted)); + + /* The bitmap write may have failed, causing a state change. */ + if (mdev->state.disk < D_INCONSISTENT) { + dev_err(DEV, + "disk is %s, cannot write al transaction (-%d +%d)\n", + drbd_disk_str(mdev->state.disk), evicted, new_enr); + complete(&((struct update_al_work *)w)->event); + put_ldev(mdev); + return 1; + } + + mutex_lock(&mdev->md_io_mutex); /* protects md_io_buffer, al_tr_cycle, ... */ + buffer = (struct al_transaction *)page_address(mdev->md_io_page); + + buffer->magic = __constant_cpu_to_be32(DRBD_MAGIC); + buffer->tr_number = cpu_to_be32(mdev->al_tr_number); + + n = lc_index_of(mdev->act_log, updated); + + buffer->updates[0].pos = cpu_to_be32(n); + buffer->updates[0].extent = cpu_to_be32(new_enr); + + xor_sum ^= new_enr; + + mx = min_t(int, AL_EXTENTS_PT, + mdev->act_log->nr_elements - mdev->al_tr_cycle); + for (i = 0; i < mx; i++) { + unsigned idx = mdev->al_tr_cycle + i; + extent_nr = lc_element_by_index(mdev->act_log, idx)->lc_number; + buffer->updates[i+1].pos = cpu_to_be32(idx); + buffer->updates[i+1].extent = cpu_to_be32(extent_nr); + xor_sum ^= extent_nr; + } + for (; i < AL_EXTENTS_PT; i++) { + buffer->updates[i+1].pos = __constant_cpu_to_be32(-1); + buffer->updates[i+1].extent = __constant_cpu_to_be32(LC_FREE); + xor_sum ^= LC_FREE; + } + mdev->al_tr_cycle += AL_EXTENTS_PT; + if (mdev->al_tr_cycle >= mdev->act_log->nr_elements) + mdev->al_tr_cycle = 0; + + buffer->xor_sum = cpu_to_be32(xor_sum); + + sector = mdev->ldev->md.md_offset + + mdev->ldev->md.al_offset + mdev->al_tr_pos; + + if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) + drbd_chk_io_error(mdev, 1, true); + + if (++mdev->al_tr_pos > + div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT)) + mdev->al_tr_pos = 0; + + D_ASSERT(mdev->al_tr_pos < MD_AL_MAX_SIZE); + mdev->al_tr_number++; + + mutex_unlock(&mdev->md_io_mutex); + + complete(&((struct update_al_work *)w)->event); + put_ldev(mdev); + + return 1; +} + +/** + * drbd_al_read_tr() - Read a single transaction from the on disk activity log + * @mdev: DRBD device. + * @bdev: Block device to read form. + * @b: pointer to an al_transaction. + * @index: On disk slot of the transaction to read. + * + * Returns -1 on IO error, 0 on checksum error and 1 upon success. + */ +static int drbd_al_read_tr(struct drbd_conf *mdev, + struct drbd_backing_dev *bdev, + struct al_transaction *b, + int index) +{ + sector_t sector; + int rv, i; + u32 xor_sum = 0; + + sector = bdev->md.md_offset + bdev->md.al_offset + index; + + /* Dont process error normally, + * as this is done before disk is attached! */ + if (!drbd_md_sync_page_io(mdev, bdev, sector, READ)) + return -1; + + rv = (be32_to_cpu(b->magic) == DRBD_MAGIC); + + for (i = 0; i < AL_EXTENTS_PT + 1; i++) + xor_sum ^= be32_to_cpu(b->updates[i].extent); + rv &= (xor_sum == be32_to_cpu(b->xor_sum)); + + return rv; +} + +/** + * drbd_al_read_log() - Restores the activity log from its on disk representation. + * @mdev: DRBD device. + * @bdev: Block device to read form. + * + * Returns 1 on success, returns 0 when reading the log failed due to IO errors. + */ +int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev) +{ + struct al_transaction *buffer; + int i; + int rv; + int mx; + int active_extents = 0; + int transactions = 0; + int found_valid = 0; + int from = 0; + int to = 0; + u32 from_tnr = 0; + u32 to_tnr = 0; + u32 cnr; + + mx = div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT); + + /* lock out all other meta data io for now, + * and make sure the page is mapped. + */ + mutex_lock(&mdev->md_io_mutex); + buffer = page_address(mdev->md_io_page); + + /* Find the valid transaction in the log */ + for (i = 0; i <= mx; i++) { + rv = drbd_al_read_tr(mdev, bdev, buffer, i); + if (rv == 0) + continue; + if (rv == -1) { + mutex_unlock(&mdev->md_io_mutex); + return 0; + } + cnr = be32_to_cpu(buffer->tr_number); + + if (++found_valid == 1) { + from = i; + to = i; + from_tnr = cnr; + to_tnr = cnr; + continue; + } + if ((int)cnr - (int)from_tnr < 0) { + D_ASSERT(from_tnr - cnr + i - from == mx+1); + from = i; + from_tnr = cnr; + } + if ((int)cnr - (int)to_tnr > 0) { + D_ASSERT(cnr - to_tnr == i - to); + to = i; + to_tnr = cnr; + } + } + + if (!found_valid) { + dev_warn(DEV, "No usable activity log found.\n"); + mutex_unlock(&mdev->md_io_mutex); + return 1; + } + + /* Read the valid transactions. + * dev_info(DEV, "Reading from %d to %d.\n",from,to); */ + i = from; + while (1) { + int j, pos; + unsigned int extent_nr; + unsigned int trn; + + rv = drbd_al_read_tr(mdev, bdev, buffer, i); + ERR_IF(rv == 0) goto cancel; + if (rv == -1) { + mutex_unlock(&mdev->md_io_mutex); + return 0; + } + + trn = be32_to_cpu(buffer->tr_number); + + spin_lock_irq(&mdev->al_lock); + + /* This loop runs backwards because in the cyclic + elements there might be an old version of the + updated element (in slot 0). So the element in slot 0 + can overwrite old versions. */ + for (j = AL_EXTENTS_PT; j >= 0; j--) { + pos = be32_to_cpu(buffer->updates[j].pos); + extent_nr = be32_to_cpu(buffer->updates[j].extent); + + if (extent_nr == LC_FREE) + continue; + + lc_set(mdev->act_log, extent_nr, pos); + active_extents++; + } + spin_unlock_irq(&mdev->al_lock); + + transactions++; + +cancel: + if (i == to) + break; + i++; + if (i > mx) + i = 0; + } + + mdev->al_tr_number = to_tnr+1; + mdev->al_tr_pos = to; + if (++mdev->al_tr_pos > + div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT)) + mdev->al_tr_pos = 0; + + /* ok, we are done with it */ + mutex_unlock(&mdev->md_io_mutex); + + dev_info(DEV, "Found %d transactions (%d active extents) in activity log.\n", + transactions, active_extents); + + return 1; +} + +/** + * drbd_al_apply_to_bm() - Sets the bitmap to diry(1) where covered ba active AL extents + * @mdev: DRBD device. + */ +void drbd_al_apply_to_bm(struct drbd_conf *mdev) +{ + unsigned int enr; + unsigned long add = 0; + char ppb[10]; + int i, tmp; + + wait_event(mdev->al_wait, lc_try_lock(mdev->act_log)); + + for (i = 0; i < mdev->act_log->nr_elements; i++) { + enr = lc_element_by_index(mdev->act_log, i)->lc_number; + if (enr == LC_FREE) + continue; + tmp = drbd_bm_ALe_set_all(mdev, enr); + dynamic_dev_dbg(DEV, "AL: set %d bits in extent %u\n", tmp, enr); + add += tmp; + } + + lc_unlock(mdev->act_log); + wake_up(&mdev->al_wait); + + dev_info(DEV, "Marked additional %s as out-of-sync based on AL.\n", + ppsize(ppb, Bit2KB(add))); +} + +static int _try_lc_del(struct drbd_conf *mdev, struct lc_element *al_ext) +{ + int rv; + + spin_lock_irq(&mdev->al_lock); + rv = (al_ext->refcnt == 0); + if (likely(rv)) + lc_del(mdev->act_log, al_ext); + spin_unlock_irq(&mdev->al_lock); + + return rv; +} + +/** + * drbd_al_shrink() - Removes all active extents form the activity log + * @mdev: DRBD device. + * + * Removes all active extents form the activity log, waiting until + * the reference count of each entry dropped to 0 first, of course. + * + * You need to lock mdev->act_log with lc_try_lock() / lc_unlock() + */ +void drbd_al_shrink(struct drbd_conf *mdev) +{ + struct lc_element *al_ext; + int i; + + D_ASSERT(test_bit(__LC_DIRTY, &mdev->act_log->flags)); + + for (i = 0; i < mdev->act_log->nr_elements; i++) { + al_ext = lc_element_by_index(mdev->act_log, i); + if (al_ext->lc_number == LC_FREE) + continue; + wait_event(mdev->al_wait, _try_lc_del(mdev, al_ext)); + } + + wake_up(&mdev->al_wait); +} + +static int w_update_odbm(struct drbd_conf *mdev, struct drbd_work *w, int unused) +{ + struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w); + + if (!get_ldev(mdev)) { + if (__ratelimit(&drbd_ratelimit_state)) + dev_warn(DEV, "Can not update on disk bitmap, local IO disabled.\n"); + kfree(udw); + return 1; + } + + drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr)); + put_ldev(mdev); + + kfree(udw); + + if (drbd_bm_total_weight(mdev) <= mdev->rs_failed) { + switch (mdev->state.conn) { + case C_SYNC_SOURCE: case C_SYNC_TARGET: + case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T: + drbd_resync_finished(mdev); + default: + /* nothing to do */ + break; + } + } + drbd_bcast_sync_progress(mdev); + + return 1; +} + + +/* ATTENTION. The AL's extents are 4MB each, while the extents in the + * resync LRU-cache are 16MB each. + * The caller of this function has to hold an get_ldev() reference. + * + * TODO will be obsoleted once we have a caching lru of the on disk bitmap + */ +static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector, + int count, int success) +{ + struct lc_element *e; + struct update_odbm_work *udw; + + unsigned int enr; + + D_ASSERT(atomic_read(&mdev->local_cnt)); + + /* I simply assume that a sector/size pair never crosses + * a 16 MB extent border. (Currently this is true...) */ + enr = BM_SECT_TO_EXT(sector); + + e = lc_get(mdev->resync, enr); + if (e) { + struct bm_extent *ext = lc_entry(e, struct bm_extent, lce); + if (ext->lce.lc_number == enr) { + if (success) + ext->rs_left -= count; + else + ext->rs_failed += count; + if (ext->rs_left < ext->rs_failed) { + dev_err(DEV, "BAD! sector=%llus enr=%u rs_left=%d " + "rs_failed=%d count=%d\n", + (unsigned long long)sector, + ext->lce.lc_number, ext->rs_left, + ext->rs_failed, count); + dump_stack(); + + lc_put(mdev->resync, &ext->lce); + drbd_force_state(mdev, NS(conn, C_DISCONNECTING)); + return; + } + } else { + /* Normally this element should be in the cache, + * since drbd_rs_begin_io() pulled it already in. + * + * But maybe an application write finished, and we set + * something outside the resync lru_cache in sync. + */ + int rs_left = drbd_bm_e_weight(mdev, enr); + if (ext->flags != 0) { + dev_warn(DEV, "changing resync lce: %d[%u;%02lx]" + " -> %d[%u;00]\n", + ext->lce.lc_number, ext->rs_left, + ext->flags, enr, rs_left); + ext->flags = 0; + } + if (ext->rs_failed) { + dev_warn(DEV, "Kicking resync_lru element enr=%u " + "out with rs_failed=%d\n", + ext->lce.lc_number, ext->rs_failed); + } + ext->rs_left = rs_left; + ext->rs_failed = success ? 0 : count; + lc_changed(mdev->resync, &ext->lce); + } + lc_put(mdev->resync, &ext->lce); + /* no race, we are within the al_lock! */ + + if (ext->rs_left == ext->rs_failed) { + ext->rs_failed = 0; + + udw = kmalloc(sizeof(*udw), GFP_ATOMIC); + if (udw) { + udw->enr = ext->lce.lc_number; + udw->w.cb = w_update_odbm; + drbd_queue_work_front(&mdev->data.work, &udw->w); + } else { + dev_warn(DEV, "Could not kmalloc an udw\n"); + } + } + } else { + dev_err(DEV, "lc_get() failed! locked=%d/%d flags=%lu\n", + mdev->resync_locked, + mdev->resync->nr_elements, + mdev->resync->flags); + } +} + +void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go) +{ + unsigned long now = jiffies; + unsigned long last = mdev->rs_mark_time[mdev->rs_last_mark]; + int next = (mdev->rs_last_mark + 1) % DRBD_SYNC_MARKS; + if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) { + if (mdev->rs_mark_left[mdev->rs_last_mark] != still_to_go && + mdev->state.conn != C_PAUSED_SYNC_T && + mdev->state.conn != C_PAUSED_SYNC_S) { + mdev->rs_mark_time[next] = now; + mdev->rs_mark_left[next] = still_to_go; + mdev->rs_last_mark = next; + } + } +} + +/* clear the bit corresponding to the piece of storage in question: + * size byte of data starting from sector. Only clear a bits of the affected + * one ore more _aligned_ BM_BLOCK_SIZE blocks. + * + * called by worker on C_SYNC_TARGET and receiver on SyncSource. + * + */ +void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size, + const char *file, const unsigned int line) +{ + /* Is called from worker and receiver context _only_ */ + unsigned long sbnr, ebnr, lbnr; + unsigned long count = 0; + sector_t esector, nr_sectors; + int wake_up = 0; + unsigned long flags; + + if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) { + dev_err(DEV, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n", + (unsigned long long)sector, size); + return; + } + nr_sectors = drbd_get_capacity(mdev->this_bdev); + esector = sector + (size >> 9) - 1; + + ERR_IF(sector >= nr_sectors) return; + ERR_IF(esector >= nr_sectors) esector = (nr_sectors-1); + + lbnr = BM_SECT_TO_BIT(nr_sectors-1); + + /* we clear it (in sync). + * round up start sector, round down end sector. we make sure we only + * clear full, aligned, BM_BLOCK_SIZE (4K) blocks */ + if (unlikely(esector < BM_SECT_PER_BIT-1)) + return; + if (unlikely(esector == (nr_sectors-1))) + ebnr = lbnr; + else + ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); + sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); + + if (sbnr > ebnr) + return; + + /* + * ok, (capacity & 7) != 0 sometimes, but who cares... + * we count rs_{total,left} in bits, not sectors. + */ + count = drbd_bm_clear_bits(mdev, sbnr, ebnr); + if (count && get_ldev(mdev)) { + drbd_advance_rs_marks(mdev, drbd_bm_total_weight(mdev)); + spin_lock_irqsave(&mdev->al_lock, flags); + drbd_try_clear_on_disk_bm(mdev, sector, count, true); + spin_unlock_irqrestore(&mdev->al_lock, flags); + + /* just wake_up unconditional now, various lc_chaged(), + * lc_put() in drbd_try_clear_on_disk_bm(). */ + wake_up = 1; + put_ldev(mdev); + } + if (wake_up) + wake_up(&mdev->al_wait); +} + +/* + * this is intended to set one request worth of data out of sync. + * affects at least 1 bit, + * and at most 1+DRBD_MAX_BIO_SIZE/BM_BLOCK_SIZE bits. + * + * called by tl_clear and drbd_send_dblock (==drbd_make_request). + * so this can be _any_ process. + */ +int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size, + const char *file, const unsigned int line) +{ + unsigned long sbnr, ebnr, lbnr, flags; + sector_t esector, nr_sectors; + unsigned int enr, count = 0; + struct lc_element *e; + + if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) { + dev_err(DEV, "sector: %llus, size: %d\n", + (unsigned long long)sector, size); + return 0; + } + + if (!get_ldev(mdev)) + return 0; /* no disk, no metadata, no bitmap to set bits in */ + + nr_sectors = drbd_get_capacity(mdev->this_bdev); + esector = sector + (size >> 9) - 1; + + ERR_IF(sector >= nr_sectors) + goto out; + ERR_IF(esector >= nr_sectors) + esector = (nr_sectors-1); + + lbnr = BM_SECT_TO_BIT(nr_sectors-1); + + /* we set it out of sync, + * we do not need to round anything here */ + sbnr = BM_SECT_TO_BIT(sector); + ebnr = BM_SECT_TO_BIT(esector); + + /* ok, (capacity & 7) != 0 sometimes, but who cares... + * we count rs_{total,left} in bits, not sectors. */ + spin_lock_irqsave(&mdev->al_lock, flags); + count = drbd_bm_set_bits(mdev, sbnr, ebnr); + + enr = BM_SECT_TO_EXT(sector); + e = lc_find(mdev->resync, enr); + if (e) + lc_entry(e, struct bm_extent, lce)->rs_left += count; + spin_unlock_irqrestore(&mdev->al_lock, flags); + +out: + put_ldev(mdev); + + return count; +} + +static +struct bm_extent *_bme_get(struct drbd_conf *mdev, unsigned int enr) +{ + struct lc_element *e; + struct bm_extent *bm_ext; + int wakeup = 0; + unsigned long rs_flags; + + spin_lock_irq(&mdev->al_lock); + if (mdev->resync_locked > mdev->resync->nr_elements/2) { + spin_unlock_irq(&mdev->al_lock); + return NULL; + } + e = lc_get(mdev->resync, enr); + bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; + if (bm_ext) { + if (bm_ext->lce.lc_number != enr) { + bm_ext->rs_left = drbd_bm_e_weight(mdev, enr); + bm_ext->rs_failed = 0; + lc_changed(mdev->resync, &bm_ext->lce); + wakeup = 1; + } + if (bm_ext->lce.refcnt == 1) + mdev->resync_locked++; + set_bit(BME_NO_WRITES, &bm_ext->flags); + } + rs_flags = mdev->resync->flags; + spin_unlock_irq(&mdev->al_lock); + if (wakeup) + wake_up(&mdev->al_wait); + + if (!bm_ext) { + if (rs_flags & LC_STARVING) + dev_warn(DEV, "Have to wait for element" + " (resync LRU too small?)\n"); + BUG_ON(rs_flags & LC_DIRTY); + } + + return bm_ext; +} + +static int _is_in_al(struct drbd_conf *mdev, unsigned int enr) +{ + struct lc_element *al_ext; + int rv = 0; + + spin_lock_irq(&mdev->al_lock); + if (unlikely(enr == mdev->act_log->new_number)) + rv = 1; + else { + al_ext = lc_find(mdev->act_log, enr); + if (al_ext) { + if (al_ext->refcnt) + rv = 1; + } + } + spin_unlock_irq(&mdev->al_lock); + + /* + if (unlikely(rv)) { + dev_info(DEV, "Delaying sync read until app's write is done\n"); + } + */ + return rv; +} + +/** + * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED + * @mdev: DRBD device. + * @sector: The sector number. + * + * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted. + */ +int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector) +{ + unsigned int enr = BM_SECT_TO_EXT(sector); + struct bm_extent *bm_ext; + int i, sig; + int sa = 200; /* Step aside 200 times, then grab the extent and let app-IO wait. + 200 times -> 20 seconds. */ + +retry: + sig = wait_event_interruptible(mdev->al_wait, + (bm_ext = _bme_get(mdev, enr))); + if (sig) + return -EINTR; + + if (test_bit(BME_LOCKED, &bm_ext->flags)) + return 0; + + for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { + sig = wait_event_interruptible(mdev->al_wait, + !_is_in_al(mdev, enr * AL_EXT_PER_BM_SECT + i) || + test_bit(BME_PRIORITY, &bm_ext->flags)); + + if (sig || (test_bit(BME_PRIORITY, &bm_ext->flags) && sa)) { + spin_lock_irq(&mdev->al_lock); + if (lc_put(mdev->resync, &bm_ext->lce) == 0) { + bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */ + mdev->resync_locked--; + wake_up(&mdev->al_wait); + } + spin_unlock_irq(&mdev->al_lock); + if (sig) + return -EINTR; + if (schedule_timeout_interruptible(HZ/10)) + return -EINTR; + if (sa && --sa == 0) + dev_warn(DEV,"drbd_rs_begin_io() stepped aside for 20sec." + "Resync stalled?\n"); + goto retry; + } + } + set_bit(BME_LOCKED, &bm_ext->flags); + return 0; +} + +/** + * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep + * @mdev: DRBD device. + * @sector: The sector number. + * + * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then + * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN + * if there is still application IO going on in this area. + */ +int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector) +{ + unsigned int enr = BM_SECT_TO_EXT(sector); + const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT; + struct lc_element *e; + struct bm_extent *bm_ext; + int i; + + spin_lock_irq(&mdev->al_lock); + if (mdev->resync_wenr != LC_FREE && mdev->resync_wenr != enr) { + /* in case you have very heavy scattered io, it may + * stall the syncer undefined if we give up the ref count + * when we try again and requeue. + * + * if we don't give up the refcount, but the next time + * we are scheduled this extent has been "synced" by new + * application writes, we'd miss the lc_put on the + * extent we keep the refcount on. + * so we remembered which extent we had to try again, and + * if the next requested one is something else, we do + * the lc_put here... + * we also have to wake_up + */ + e = lc_find(mdev->resync, mdev->resync_wenr); + bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; + if (bm_ext) { + D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags)); + D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags)); + clear_bit(BME_NO_WRITES, &bm_ext->flags); + mdev->resync_wenr = LC_FREE; + if (lc_put(mdev->resync, &bm_ext->lce) == 0) + mdev->resync_locked--; + wake_up(&mdev->al_wait); + } else { + dev_alert(DEV, "LOGIC BUG\n"); + } + } + /* TRY. */ + e = lc_try_get(mdev->resync, enr); + bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; + if (bm_ext) { + if (test_bit(BME_LOCKED, &bm_ext->flags)) + goto proceed; + if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) { + mdev->resync_locked++; + } else { + /* we did set the BME_NO_WRITES, + * but then could not set BME_LOCKED, + * so we tried again. + * drop the extra reference. */ + bm_ext->lce.refcnt--; + D_ASSERT(bm_ext->lce.refcnt > 0); + } + goto check_al; + } else { + /* do we rather want to try later? */ + if (mdev->resync_locked > mdev->resync->nr_elements-3) + goto try_again; + /* Do or do not. There is no try. -- Yoda */ + e = lc_get(mdev->resync, enr); + bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; + if (!bm_ext) { + const unsigned long rs_flags = mdev->resync->flags; + if (rs_flags & LC_STARVING) + dev_warn(DEV, "Have to wait for element" + " (resync LRU too small?)\n"); + BUG_ON(rs_flags & LC_DIRTY); + goto try_again; + } + if (bm_ext->lce.lc_number != enr) { + bm_ext->rs_left = drbd_bm_e_weight(mdev, enr); + bm_ext->rs_failed = 0; + lc_changed(mdev->resync, &bm_ext->lce); + wake_up(&mdev->al_wait); + D_ASSERT(test_bit(BME_LOCKED, &bm_ext->flags) == 0); + } + set_bit(BME_NO_WRITES, &bm_ext->flags); + D_ASSERT(bm_ext->lce.refcnt == 1); + mdev->resync_locked++; + goto check_al; + } +check_al: + for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { + if (unlikely(al_enr+i == mdev->act_log->new_number)) + goto try_again; + if (lc_is_used(mdev->act_log, al_enr+i)) + goto try_again; + } + set_bit(BME_LOCKED, &bm_ext->flags); +proceed: + mdev->resync_wenr = LC_FREE; + spin_unlock_irq(&mdev->al_lock); + return 0; + +try_again: + if (bm_ext) + mdev->resync_wenr = enr; + spin_unlock_irq(&mdev->al_lock); + return -EAGAIN; +} + +void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector) +{ + unsigned int enr = BM_SECT_TO_EXT(sector); + struct lc_element *e; + struct bm_extent *bm_ext; + unsigned long flags; + + spin_lock_irqsave(&mdev->al_lock, flags); + e = lc_find(mdev->resync, enr); + bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; + if (!bm_ext) { + spin_unlock_irqrestore(&mdev->al_lock, flags); + if (__ratelimit(&drbd_ratelimit_state)) + dev_err(DEV, "drbd_rs_complete_io() called, but extent not found\n"); + return; + } + + if (bm_ext->lce.refcnt == 0) { + spin_unlock_irqrestore(&mdev->al_lock, flags); + dev_err(DEV, "drbd_rs_complete_io(,%llu [=%u]) called, " + "but refcnt is 0!?\n", + (unsigned long long)sector, enr); + return; + } + + if (lc_put(mdev->resync, &bm_ext->lce) == 0) { + bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */ + mdev->resync_locked--; + wake_up(&mdev->al_wait); + } + + spin_unlock_irqrestore(&mdev->al_lock, flags); +} + +/** + * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED) + * @mdev: DRBD device. + */ +void drbd_rs_cancel_all(struct drbd_conf *mdev) +{ + spin_lock_irq(&mdev->al_lock); + + if (get_ldev_if_state(mdev, D_FAILED)) { /* Makes sure ->resync is there. */ + lc_reset(mdev->resync); + put_ldev(mdev); + } + mdev->resync_locked = 0; + mdev->resync_wenr = LC_FREE; + spin_unlock_irq(&mdev->al_lock); + wake_up(&mdev->al_wait); +} + +/** + * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU + * @mdev: DRBD device. + * + * Returns 0 upon success, -EAGAIN if at least one reference count was + * not zero. + */ +int drbd_rs_del_all(struct drbd_conf *mdev) +{ + struct lc_element *e; + struct bm_extent *bm_ext; + int i; + + spin_lock_irq(&mdev->al_lock); + + if (get_ldev_if_state(mdev, D_FAILED)) { + /* ok, ->resync is there. */ + for (i = 0; i < mdev->resync->nr_elements; i++) { + e = lc_element_by_index(mdev->resync, i); + bm_ext = lc_entry(e, struct bm_extent, lce); + if (bm_ext->lce.lc_number == LC_FREE) + continue; + if (bm_ext->lce.lc_number == mdev->resync_wenr) { + dev_info(DEV, "dropping %u in drbd_rs_del_all, apparently" + " got 'synced' by application io\n", + mdev->resync_wenr); + D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags)); + D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags)); + clear_bit(BME_NO_WRITES, &bm_ext->flags); + mdev->resync_wenr = LC_FREE; + lc_put(mdev->resync, &bm_ext->lce); + } + if (bm_ext->lce.refcnt != 0) { + dev_info(DEV, "Retrying drbd_rs_del_all() later. " + "refcnt=%d\n", bm_ext->lce.refcnt); + put_ldev(mdev); + spin_unlock_irq(&mdev->al_lock); + return -EAGAIN; + } + D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags)); + D_ASSERT(!test_bit(BME_NO_WRITES, &bm_ext->flags)); + lc_del(mdev->resync, &bm_ext->lce); + } + D_ASSERT(mdev->resync->used == 0); + put_ldev(mdev); + } + spin_unlock_irq(&mdev->al_lock); + + return 0; +} + +/** + * drbd_rs_failed_io() - Record information on a failure to resync the specified blocks + * @mdev: DRBD device. + * @sector: The sector number. + * @size: Size of failed IO operation, in byte. + */ +void drbd_rs_failed_io(struct drbd_conf *mdev, sector_t sector, int size) +{ + /* Is called from worker and receiver context _only_ */ + unsigned long sbnr, ebnr, lbnr; + unsigned long count; + sector_t esector, nr_sectors; + int wake_up = 0; + + if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) { + dev_err(DEV, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n", + (unsigned long long)sector, size); + return; + } + nr_sectors = drbd_get_capacity(mdev->this_bdev); + esector = sector + (size >> 9) - 1; + + ERR_IF(sector >= nr_sectors) return; + ERR_IF(esector >= nr_sectors) esector = (nr_sectors-1); + + lbnr = BM_SECT_TO_BIT(nr_sectors-1); + + /* + * round up start sector, round down end sector. we make sure we only + * handle full, aligned, BM_BLOCK_SIZE (4K) blocks */ + if (unlikely(esector < BM_SECT_PER_BIT-1)) + return; + if (unlikely(esector == (nr_sectors-1))) + ebnr = lbnr; + else + ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); + sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); + + if (sbnr > ebnr) + return; + + /* + * ok, (capacity & 7) != 0 sometimes, but who cares... + * we count rs_{total,left} in bits, not sectors. + */ + spin_lock_irq(&mdev->al_lock); + count = drbd_bm_count_bits(mdev, sbnr, ebnr); + if (count) { + mdev->rs_failed += count; + + if (get_ldev(mdev)) { + drbd_try_clear_on_disk_bm(mdev, sector, count, false); + put_ldev(mdev); + } + + /* just wake_up unconditional now, various lc_chaged(), + * lc_put() in drbd_try_clear_on_disk_bm(). */ + wake_up = 1; + } + spin_unlock_irq(&mdev->al_lock); + if (wake_up) + wake_up(&mdev->al_wait); +} |