From 80a40e439e5a3f30b0a6210a1add6d7c33392e54 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Wed, 11 Aug 2010 23:28:00 +0200 Subject: [PATCH] drbd: reduce code duplication when receiving data requests also canonicalize the return values of read_for_csum and drbd_rs_begin_io to return -ESOMETHING, or 0 for success. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_actlog.c | 12 +++++----- drivers/block/drbd/drbd_receiver.c | 46 ++++++++++---------------------------- drivers/block/drbd/drbd_worker.c | 22 ++++++++++-------- 3 files changed, 30 insertions(+), 50 deletions(-) diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index b895470..ac04ef9 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -1119,7 +1119,7 @@ static int _is_in_al(struct drbd_conf *mdev, unsigned int enr) * @mdev: DRBD device. * @sector: The sector number. * - * This functions sleeps on al_wait. Returns 1 on success, 0 if interrupted. + * 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) { @@ -1130,10 +1130,10 @@ int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector) sig = wait_event_interruptible(mdev->al_wait, (bm_ext = _bme_get(mdev, enr))); if (sig) - return 0; + return -EINTR; if (test_bit(BME_LOCKED, &bm_ext->flags)) - return 1; + return 0; for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { sig = wait_event_interruptible(mdev->al_wait, @@ -1146,13 +1146,11 @@ int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector) wake_up(&mdev->al_wait); } spin_unlock_irq(&mdev->al_lock); - return 0; + return -EINTR; } } - set_bit(BME_LOCKED, &bm_ext->flags); - - return 1; + return 0; } /** diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 2f9320b..346aed9 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -2068,21 +2068,12 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h) case P_DATA_REQUEST: e->w.cb = w_e_end_data_req; fault_type = DRBD_FAULT_DT_RD; - break; + /* application IO, don't drbd_rs_begin_io */ + goto submit; + case P_RS_DATA_REQUEST: e->w.cb = w_e_end_rsdata_req; fault_type = DRBD_FAULT_RS_RD; - /* Eventually this should become asynchronously. Currently it - * blocks the whole receiver just to delay the reading of a - * resync data block. - * the drbd_work_queue mechanism is made for this... - */ - if (!drbd_rs_begin_io(mdev, sector)) { - /* we have been interrupted, - * probably connection lost! */ - D_ASSERT(signal_pending(current)); - goto out_free_e; - } break; case P_OV_REPLY: @@ -2108,13 +2099,8 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h) } else if (h->command == P_OV_REPLY) { e->w.cb = w_e_end_ov_reply; dec_rs_pending(mdev); - break; - } - - if (!drbd_rs_begin_io(mdev, sector)) { - /* we have been interrupted, probably connection lost! */ - D_ASSERT(signal_pending(current)); - goto out_free_e; + /* drbd_rs_begin_io done when we sent this request */ + goto submit; } break; @@ -2133,31 +2119,23 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h) } e->w.cb = w_e_end_ov_req; fault_type = DRBD_FAULT_RS_RD; - /* Eventually this should become asynchronous. Currently it - * blocks the whole receiver just to delay the reading of a - * resync data block. - * the drbd_work_queue mechanism is made for this... - */ - if (!drbd_rs_begin_io(mdev, sector)) { - /* we have been interrupted, - * probably connection lost! */ - D_ASSERT(signal_pending(current)); - goto out_free_e; - } break; - default: dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n", cmdname(h->command)); fault_type = DRBD_FAULT_MAX; + goto out_free_e; } - spin_lock_irq(&mdev->req_lock); - list_add(&e->w.list, &mdev->read_ee); - spin_unlock_irq(&mdev->req_lock); + if (drbd_rs_begin_io(mdev, e->sector)) + goto out_free_e; +submit: inc_unacked(mdev); + spin_lock_irq(&mdev->req_lock); + list_add_tail(&e->w.list, &mdev->read_ee); + spin_unlock_irq(&mdev->req_lock); if (drbd_submit_ee(mdev, e, READ, fault_type) == 0) return TRUE; diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 53b7425..f5d779b 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -374,26 +374,26 @@ static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size) struct drbd_epoch_entry *e; if (!get_ldev(mdev)) - return 0; + 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. */ e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY); if (!e) - goto fail; + goto defer; + e->w.cb = w_e_send_csum; spin_lock_irq(&mdev->req_lock); list_add(&e->w.list, &mdev->read_ee); spin_unlock_irq(&mdev->req_lock); - e->w.cb = w_e_send_csum; if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0) - return 1; + return 0; drbd_free_ee(mdev, e); -fail: +defer: put_ldev(mdev); - return 2; + return -EAGAIN; } void resync_timer_fn(unsigned long data) @@ -649,15 +649,19 @@ next_sector: size = (capacity-sector)<<9; if (mdev->agreed_pro_version >= 89 && mdev->csums_tfm) { switch (read_for_csum(mdev, sector, size)) { - case 0: /* Disk failure*/ + case -EIO: /* Disk failure */ put_ldev(mdev); return 0; - case 2: /* Allocation failed */ + case -EAGAIN: /* allocation failed, or ldev busy */ drbd_rs_complete_io(mdev, sector); mdev->bm_resync_fo = BM_SECT_TO_BIT(sector); i = rollback_i; goto requeue; - /* case 1: everything ok */ + case 0: + /* everything ok */ + break; + default: + BUG(); } } else { inc_rs_pending(mdev); -- 2.7.4