From 39a1aa7f49dc8eae5c8d3a4bf759eb7abeabe6c0 Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Wed, 8 Aug 2012 21:19:09 +0200 Subject: [PATCH] drbd: Protect accesses to the uuid set with a spinlock There is at least the worker context, the receiver context, the context of receiving netlink packts. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_int.h | 4 +++- drivers/block/drbd/drbd_main.c | 33 +++++++++++++++++++++++++++------ drivers/block/drbd/drbd_nl.c | 12 +++++++++++- drivers/block/drbd/drbd_receiver.c | 11 ++++++++--- 4 files changed, 49 insertions(+), 11 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index d8b3c88..b83398d 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -747,6 +747,7 @@ struct drbd_md { u64 md_offset; /* sector offset to 'super' block */ u64 la_size_sect; /* last agreed size, unit sectors */ + spinlock_t uuid_lock; u64 uuid[UI_SIZE]; u64 device_uuid; u32 flags; @@ -1119,8 +1120,9 @@ extern int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev); extern void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); extern void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); extern void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local); -extern void _drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local); extern void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local); +extern void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local); +extern void __drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local); extern void drbd_md_set_flag(struct drbd_conf *mdev, int flags) __must_hold(local); extern void drbd_md_clear_flag(struct drbd_conf *mdev, int flags)__must_hold(local); extern int drbd_md_test_flag(struct drbd_backing_dev *, int); diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 328ce80..d831e85 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -838,8 +838,10 @@ int _drbd_send_uuids(struct drbd_conf *mdev, u64 uuid_flags) put_ldev(mdev); return -EIO; } + spin_lock_irq(&mdev->ldev->md.uuid_lock); for (i = UI_CURRENT; i < UI_SIZE; i++) p->uuid[i] = mdev->ldev ? cpu_to_be64(mdev->ldev->md.uuid[i]) : 0; + spin_unlock_irq(&mdev->ldev->md.uuid_lock); mdev->comm_bm_set = drbd_bm_total_weight(mdev); p->uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set); @@ -3015,7 +3017,7 @@ void drbd_md_mark_dirty(struct drbd_conf *mdev) } #endif -static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local) +void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local) { int i; @@ -3023,7 +3025,7 @@ static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local) mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i]; } -void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) +void __drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) { if (idx == UI_CURRENT) { if (mdev->state.role == R_PRIMARY) @@ -3038,14 +3040,24 @@ void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) drbd_md_mark_dirty(mdev); } +void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) +{ + unsigned long flags; + spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags); + __drbd_uuid_set(mdev, idx, val); + spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags); +} void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) { + unsigned long flags; + spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags); if (mdev->ldev->md.uuid[idx]) { drbd_uuid_move_history(mdev); mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx]; } - _drbd_uuid_set(mdev, idx, val); + __drbd_uuid_set(mdev, idx, val); + spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags); } /** @@ -3058,15 +3070,20 @@ void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local) { u64 val; - unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP]; + unsigned long long bm_uuid; + + get_random_bytes(&val, sizeof(u64)); + + spin_lock_irq(&mdev->ldev->md.uuid_lock); + bm_uuid = mdev->ldev->md.uuid[UI_BITMAP]; if (bm_uuid) dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid); mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT]; + __drbd_uuid_set(mdev, UI_CURRENT, val); + spin_unlock_irq(&mdev->ldev->md.uuid_lock); - get_random_bytes(&val, sizeof(u64)); - _drbd_uuid_set(mdev, UI_CURRENT, val); drbd_print_uuids(mdev, "new current UUID"); /* get it to stable storage _now_ */ drbd_md_sync(mdev); @@ -3074,9 +3091,11 @@ void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local) void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local) { + unsigned long flags; if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0) return; + spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags); if (val == 0) { drbd_uuid_move_history(mdev); mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP]; @@ -3088,6 +3107,8 @@ void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local) mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1); } + spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags); + drbd_md_mark_dirty(mdev); } diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index c02d526..d31a026 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1320,6 +1320,8 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) retcode = ERR_NOMEM; goto fail; } + spin_lock_init(&nbc->md.uuid_lock); + new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL); if (!new_disk_conf) { retcode = ERR_NOMEM; @@ -2679,8 +2681,16 @@ int nla_put_status_info(struct sk_buff *skb, struct drbd_conf *mdev, goto nla_put_failure; if (got_ldev) { + int err; + + spin_lock_irq(&mdev->ldev->md.uuid_lock); + err = nla_put(skb, T_uuids, sizeof(si->uuids), mdev->ldev->md.uuid); + spin_unlock_irq(&mdev->ldev->md.uuid_lock); + + if (err) + goto nla_put_failure; + if (nla_put_u32(skb, T_disk_flags, mdev->ldev->md.flags) || - nla_put(skb, T_uuids, sizeof(si->uuids), mdev->ldev->md.uuid) || nla_put_u64(skb, T_bits_total, drbd_bm_bits(mdev)) || nla_put_u64(skb, T_bits_oos, drbd_bm_total_weight(mdev))) goto nla_put_failure; diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 14df37c..0eefbeb 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -2796,7 +2796,9 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l if ((mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) && (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) { dev_info(DEV, "was SyncSource, missed the resync finished event, corrected myself:\n"); - drbd_uuid_set_bm(mdev, 0UL); + drbd_uuid_move_history(mdev); + mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP]; + mdev->ldev->md.uuid[UI_BITMAP] = 0; drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0); @@ -2904,8 +2906,8 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l if (mdev->tconn->agreed_pro_version < 91) return -1091; - _drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]); - _drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]); + __drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]); + __drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]); dev_info(DEV, "Last syncUUID did not get through, corrected:\n"); drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, @@ -2959,11 +2961,14 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol mydisk = mdev->new_state_tmp.disk; dev_info(DEV, "drbd_sync_handshake:\n"); + + spin_lock_irq(&mdev->ldev->md.uuid_lock); drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, mdev->comm_bm_set, 0); drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]); hg = drbd_uuid_compare(mdev, &rule_nr); + spin_unlock_irq(&mdev->ldev->md.uuid_lock); dev_info(DEV, "uuid_compare()=%d by rule %d\n", hg, rule_nr); -- 2.7.4