When ploop state-machine looks at preq first time, it suspends the preq if its cluster-block matches pbd->ppb_map -- the copy of CBT mask initially. To suspend preq we simply put it to pbd->pending_tree and plo->lockout_tree.
Later, when userspace reports that out-of-band processing is done, we set PLOOP_REQ_PUSH_BACKUP bit in preq->state, re-schedule the preq and wakeup ploop state-machine. This PLOOP_REQ_PUSH_BACKUP bit lets state-machine know that given preq is OK and we shouldn't suspend further preq-s for given cluster-block anymore. Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com> --- drivers/block/ploop/dev.c | 32 +++++++++++++++++++ drivers/block/ploop/push_backup.c | 62 +++++++++++++++++++++++++++++++++++++ drivers/block/ploop/push_backup.h | 6 ++++ include/linux/ploop/ploop.h | 1 + 4 files changed, 101 insertions(+) diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c index 2a77d2e..c7cc385 100644 --- a/drivers/block/ploop/dev.c +++ b/drivers/block/ploop/dev.c @@ -2021,6 +2021,38 @@ restart: return; } + /* push_backup special processing */ + if (!test_bit(PLOOP_REQ_LOCKOUT, &preq->state) && + (preq->req_rw & REQ_WRITE) && preq->req_size && + ploop_pb_check_bit(plo->pbd, preq->req_cluster)) { + if (ploop_pb_preq_add_pending(plo->pbd, preq)) { + /* already reported by userspace push_backup */ + ploop_pb_clear_bit(plo->pbd, preq->req_cluster); + } else { + spin_lock_irq(&plo->lock); + ploop_add_lockout(preq, 0); + spin_unlock_irq(&plo->lock); + /* + * preq IN: preq is in ppb_pending tree waiting for + * out-of-band push_backup processing by userspace ... + */ + return; + } + } else if (test_bit(PLOOP_REQ_LOCKOUT, &preq->state) && + test_and_clear_bit(PLOOP_REQ_PUSH_BACKUP, &preq->state)) { + /* + * preq OUT: out-of-band push_backup processing by + * userspace done; preq was re-scheduled + */ + ploop_pb_clear_bit(plo->pbd, preq->req_cluster); + + spin_lock_irq(&plo->lock); + del_lockout(preq); + if (!list_empty(&preq->delay_list)) + list_splice_init(&preq->delay_list, plo->ready_queue.prev); + spin_unlock_irq(&plo->lock); + } + if (plo->trans_map) { err = ploop_find_trans_map(plo->trans_map, preq); if (err) { diff --git a/drivers/block/ploop/push_backup.c b/drivers/block/ploop/push_backup.c index 477caf7..488b8fb 100644 --- a/drivers/block/ploop/push_backup.c +++ b/drivers/block/ploop/push_backup.c @@ -146,6 +146,32 @@ static void set_bit_in_map(struct page **map, u64 map_max, u64 blk) do_bit_in_map(map, map_max, blk, SET_BIT); } +static void clear_bit_in_map(struct page **map, u64 map_max, u64 blk) +{ + do_bit_in_map(map, map_max, blk, CLEAR_BIT); +} + +static bool check_bit_in_map(struct page **map, u64 map_max, u64 blk) +{ + return do_bit_in_map(map, map_max, blk, CHECK_BIT); +} + +/* intentionally lockless */ +void ploop_pb_clear_bit(struct ploop_pushbackup_desc *pbd, cluster_t clu) +{ + BUG_ON(!pbd); + clear_bit_in_map(pbd->ppb_map, pbd->ppb_block_max, clu); +} + +/* intentionally lockless */ +bool ploop_pb_check_bit(struct ploop_pushbackup_desc *pbd, cluster_t clu) +{ + if (!pbd) + return false; + + return check_bit_in_map(pbd->ppb_map, pbd->ppb_block_max, clu); +} + static int convert_map_to_map(struct ploop_pushbackup_desc *pbd) { struct page **from_map = pbd->cbt_map; @@ -278,6 +304,12 @@ static void ploop_pb_add_req_to_tree(struct ploop_request *preq, rb_insert_color(&preq->reloc_link, tree); } +static void ploop_pb_add_req_to_pending(struct ploop_pushbackup_desc *pbd, + struct ploop_request *preq) +{ + ploop_pb_add_req_to_tree(preq, &pbd->pending_tree); +} + static void ploop_pb_add_req_to_reported(struct ploop_pushbackup_desc *pbd, struct ploop_request *preq) { @@ -339,6 +371,33 @@ ploop_pb_get_req_from_reported(struct ploop_pushbackup_desc *pbd, return ploop_pb_get_req_from_tree(&pbd->reported_tree, clu); } +int ploop_pb_preq_add_pending(struct ploop_pushbackup_desc *pbd, + struct ploop_request *preq) +{ + BUG_ON(!pbd); + + spin_lock(&pbd->ppb_lock); + + if (!test_bit(PLOOP_S_PUSH_BACKUP, &pbd->plo->state)) { + spin_unlock(&pbd->ppb_lock); + return -EINTR; + } + + /* if (preq matches pbd->reported_map) return -EALREADY; */ + if (preq->req_cluster < pbd->ppb_offset) { + spin_unlock(&pbd->ppb_lock); + return -EALREADY; + } + + ploop_pb_add_req_to_pending(pbd, preq); + + if (pbd->ppb_waiting) + complete(&pbd->ppb_comp); + + spin_unlock(&pbd->ppb_lock); + return 0; +} + unsigned long ploop_pb_stop(struct ploop_pushbackup_desc *pbd) { if (pbd == NULL) @@ -428,6 +487,9 @@ void ploop_pb_put_reported(struct ploop_pushbackup_desc *pbd, else n_found++; + if (preq) + __set_bit(PLOOP_REQ_PUSH_BACKUP, &preq->state); + /* * If preq not found above, it's unsolicited report. Then it's * enough to have corresponding bit set in reported_map because if diff --git a/drivers/block/ploop/push_backup.h b/drivers/block/ploop/push_backup.h index 482e070..476ac53 100644 --- a/drivers/block/ploop/push_backup.h +++ b/drivers/block/ploop/push_backup.h @@ -11,3 +11,9 @@ int ploop_pb_get_pending(struct ploop_pushbackup_desc *pbd, cluster_t *clu_p, cluster_t *len_p, unsigned n_done); void ploop_pb_put_reported(struct ploop_pushbackup_desc *pbd, cluster_t clu, cluster_t len); + +void ploop_pb_clear_bit(struct ploop_pushbackup_desc *pbd, cluster_t clu); +bool ploop_pb_check_bit(struct ploop_pushbackup_desc *pbd, cluster_t clu); + +int ploop_pb_preq_add_pending(struct ploop_pushbackup_desc *pbd, + struct ploop_request *preq); diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h index 09f419d3..762d2fd 100644 --- a/include/linux/ploop/ploop.h +++ b/include/linux/ploop/ploop.h @@ -464,6 +464,7 @@ enum PLOOP_REQ_FORCE_FLUSH, /*force flush by engine */ PLOOP_REQ_KAIO_FSYNC, /*force image fsync by KAIO module */ PLOOP_REQ_POST_SUBMIT, /* preq needs post_submit processing */ + PLOOP_REQ_PUSH_BACKUP, /* preq was ACKed by userspace push_backup */ }; enum _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel