From: Philipp Reisner Date: Wed, 9 Feb 2011 15:29:33 +0000 (+0100) Subject: drbd: Extracted is_valid_transition() out of sanitize_state() X-Git-Tag: next-20121112~60^2~1^2~3^2~471 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3509502dc88ce8226b29bea5e25edf066eca9a8a;p=karo-tx-linux.git drbd: Extracted is_valid_transition() out of sanitize_state() Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c index d5777159a2b1..3199bf92e46e 100644 --- a/drivers/block/drbd/drbd_state.c +++ b/drivers/block/drbd/drbd_state.c @@ -47,6 +47,7 @@ static void after_conn_state_ch(struct drbd_tconn *tconn, union drbd_state os, union drbd_state ns, enum chg_state_flags flags); static enum drbd_state_rv is_valid_state(struct drbd_conf *, union drbd_state); static enum drbd_state_rv is_valid_soft_transition(union drbd_state, union drbd_state); +static enum drbd_state_rv is_valid_transition(union drbd_state os, union drbd_state ns); static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state os, union drbd_state ns, const char **warn_sync_abort); @@ -112,15 +113,17 @@ _req_st_cond(struct drbd_conf *mdev, union drbd_state mask, if (test_and_clear_bit(CL_ST_CHG_FAIL, &mdev->flags)) return SS_CW_FAILED_BY_PEER; - rv = 0; spin_lock_irqsave(&mdev->tconn->req_lock, flags); os = mdev->state; ns.i = (os.i & ~mask.i) | val.i; ns = sanitize_state(mdev, os, ns, NULL); + rv = is_valid_transition(os, ns); + if (rv == SS_SUCCESS) + rv = SS_UNKNOWN_ERROR; /* cont waiting, otherwise fail. */ if (!cl_wide_st_chg(mdev, os, ns)) rv = SS_CW_NO_NEED; - if (!rv) { + if (rv == SS_UNKNOWN_ERROR) { rv = is_valid_state(mdev, ns); if (rv == SS_SUCCESS) { rv = is_valid_soft_transition(os, ns); @@ -160,8 +163,10 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask, spin_lock_irqsave(&mdev->tconn->req_lock, flags); os = mdev->state; ns.i = (os.i & ~mask.i) | val.i; - ns = sanitize_state(mdev, os, ns, NULL); + rv = is_valid_transition(os, ns); + if (rv < SS_SUCCESS) + goto abort; if (cl_wide_st_chg(mdev, os, ns)) { rv = is_valid_state(mdev, ns); @@ -340,6 +345,8 @@ is_valid_state(struct drbd_conf *mdev, union drbd_state ns) /** * is_valid_soft_transition() - Returns an SS_ error code if the state transition is not possible + * This function limits state transitions that may be declined by DRBD. I.e. + * user requests (aka soft transitions). * @mdev: DRBD device. * @ns: new state. * @os: old state. @@ -389,6 +396,40 @@ is_valid_soft_transition(union drbd_state os, union drbd_state ns) return rv; } +/** + * is_valid_transition() - Returns an SS_ error code if the state transition is not possible + * This limits hard state transitions. Hard state transitions are facts there are + * imposed on DRBD by the environment. E.g. disk broke or network broke down. + * But those hard state transitions are still not allowed to do everything. + * @ns: new state. + * @os: old state. + */ +static enum drbd_state_rv +is_valid_transition(union drbd_state os, union drbd_state ns) +{ + enum drbd_state_rv rv = SS_SUCCESS; + + /* Disallow Network errors to configure a device's network part */ + if ((ns.conn >= C_TIMEOUT && ns.conn <= C_TEAR_DOWN) && + os.conn <= C_DISCONNECTING) + rv = SS_NEED_CONNECTION; + + /* After a network error only C_UNCONNECTED or C_DISCONNECTING may follow. */ + if (os.conn >= C_TIMEOUT && os.conn <= C_TEAR_DOWN && + ns.conn != C_UNCONNECTED && ns.conn != C_DISCONNECTING) + rv = SS_IN_TRANSIENT_STATE; + + /* After C_DISCONNECTING only C_STANDALONE may follow */ + if (os.conn == C_DISCONNECTING && ns.conn != C_STANDALONE) + rv = SS_IN_TRANSIENT_STATE; + + /* we cannot fail (again) if we already detached */ + if (ns.disk == D_FAILED && os.disk == D_DISKLESS) + rv = SS_IS_DISKLESS; + + return rv; +} + /** * sanitize_state() - Resolves implicitly necessary additional changes to a state transition * @mdev: DRBD device. @@ -411,30 +452,12 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state put_ldev(mdev); } - /* Disallow Network errors to configure a device's network part */ - if ((ns.conn >= C_TIMEOUT && ns.conn <= C_TEAR_DOWN) && - os.conn <= C_DISCONNECTING) - ns.conn = os.conn; - - /* After a network error (+C_TEAR_DOWN) only C_UNCONNECTED or C_DISCONNECTING can follow. - * If you try to go into some Sync* state, that shall fail (elsewhere). */ - if (os.conn >= C_TIMEOUT && os.conn <= C_TEAR_DOWN && - ns.conn != C_UNCONNECTED && ns.conn != C_DISCONNECTING && ns.conn <= C_TEAR_DOWN) - ns.conn = os.conn; - - /* we cannot fail (again) if we already detached */ - if (ns.disk == D_FAILED && os.disk == D_DISKLESS) - ns.disk = D_DISKLESS; - /* if we are only D_ATTACHING yet, * we can (and should) go directly to D_DISKLESS. */ if (ns.disk == D_FAILED && os.disk == D_ATTACHING) ns.disk = D_DISKLESS; - /* After C_DISCONNECTING only C_STANDALONE may follow */ - if (os.conn == C_DISCONNECTING && ns.conn != C_STANDALONE) - ns.conn = os.conn; - + /* Implications from connection to peer and peer_isp */ if (ns.conn < C_CONNECTED) { ns.peer_isp = 0; ns.peer = R_UNKNOWN; @@ -641,6 +664,10 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns, if (ns.i == os.i) return SS_NOTHING_TO_DO; + rv = is_valid_transition(os, ns); + if (rv < SS_SUCCESS) + return rv; + if (!(flags & CS_HARD)) { /* pre-state-change checks ; only look at ns */ /* See drbd_state_sw_errors in drbd_strings.c */