From 475f230c6072fb2186f48b23943afcd0ee3a8343 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Thu, 2 Aug 2012 11:08:21 -0500 Subject: dlm: fix unlock balance warnings The in_recovery rw_semaphore has always been acquired and released by different threads by design. To work around the "BUG: bad unlock balance detected!" messages, adjust things so the dlm_recoverd thread always does both down_write and up_write. Signed-off-by: David Teigland --- fs/dlm/dlm_internal.h | 46 ++++++++++++++++++++++++++++++++++++---------- fs/dlm/lockspace.c | 15 ++++++++++++--- fs/dlm/member.c | 17 +++++++++++------ fs/dlm/rcom.c | 2 +- fs/dlm/recoverd.c | 27 ++++++++++++++++++--------- fs/dlm/recoverd.h | 1 - 6 files changed, 78 insertions(+), 30 deletions(-) (limited to 'fs/dlm') diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index 9d3e485f88c..871c1abf602 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -604,6 +604,7 @@ struct dlm_ls { struct idr ls_recover_idr; spinlock_t ls_recover_idr_lock; wait_queue_head_t ls_wait_general; + wait_queue_head_t ls_recover_lock_wait; struct mutex ls_clear_proc_locks; struct list_head ls_root_list; /* root resources */ @@ -616,15 +617,40 @@ struct dlm_ls { char ls_name[1]; }; -#define LSFL_WORK 0 -#define LSFL_RUNNING 1 -#define LSFL_RECOVERY_STOP 2 -#define LSFL_RCOM_READY 3 -#define LSFL_RCOM_WAIT 4 -#define LSFL_UEVENT_WAIT 5 -#define LSFL_TIMEWARN 6 -#define LSFL_CB_DELAY 7 -#define LSFL_NODIR 8 +/* + * LSFL_RECOVER_STOP - dlm_ls_stop() sets this to tell dlm recovery routines + * that they should abort what they're doing so new recovery can be started. + * + * LSFL_RECOVER_DOWN - dlm_ls_stop() sets this to tell dlm_recoverd that it + * should do down_write() on the in_recovery rw_semaphore. (doing down_write + * within dlm_ls_stop causes complaints about the lock acquired/released + * in different contexts.) + * + * LSFL_RECOVER_LOCK - dlm_recoverd holds the in_recovery rw_semaphore. + * It sets this after it is done with down_write() on the in_recovery + * rw_semaphore and clears it after it has released the rw_semaphore. + * + * LSFL_RECOVER_WORK - dlm_ls_start() sets this to tell dlm_recoverd that it + * should begin recovery of the lockspace. + * + * LSFL_RUNNING - set when normal locking activity is enabled. + * dlm_ls_stop() clears this to tell dlm locking routines that they should + * quit what they are doing so recovery can run. dlm_recoverd sets + * this after recovery is finished. + */ + +#define LSFL_RECOVER_STOP 0 +#define LSFL_RECOVER_DOWN 1 +#define LSFL_RECOVER_LOCK 2 +#define LSFL_RECOVER_WORK 3 +#define LSFL_RUNNING 4 + +#define LSFL_RCOM_READY 5 +#define LSFL_RCOM_WAIT 6 +#define LSFL_UEVENT_WAIT 7 +#define LSFL_TIMEWARN 8 +#define LSFL_CB_DELAY 9 +#define LSFL_NODIR 10 /* much of this is just saving user space pointers associated with the lock that we pass back to the user lib with an ast */ @@ -667,7 +693,7 @@ static inline int dlm_locking_stopped(struct dlm_ls *ls) static inline int dlm_recovery_stopped(struct dlm_ls *ls) { - return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags); + return test_bit(LSFL_RECOVER_STOP, &ls->ls_flags); } static inline int dlm_no_directory(struct dlm_ls *ls) diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index 952557d00cc..2e99fb0c973 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -582,8 +582,6 @@ static int new_lockspace(const char *name, const char *cluster, INIT_LIST_HEAD(&ls->ls_root_list); init_rwsem(&ls->ls_root_sem); - down_write(&ls->ls_in_recovery); - spin_lock(&lslist_lock); ls->ls_create_count = 1; list_add(&ls->ls_list, &lslist); @@ -597,13 +595,24 @@ static int new_lockspace(const char *name, const char *cluster, } } - /* needs to find ls in lslist */ + init_waitqueue_head(&ls->ls_recover_lock_wait); + + /* + * Once started, dlm_recoverd first looks for ls in lslist, then + * initializes ls_in_recovery as locked in "down" mode. We need + * to wait for the wakeup from dlm_recoverd because in_recovery + * has to start out in down mode. + */ + error = dlm_recoverd_start(ls); if (error) { log_error(ls, "can't start dlm_recoverd %d", error); goto out_callback; } + wait_event(ls->ls_recover_lock_wait, + test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags)); + ls->ls_kobj.kset = dlm_kset; error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL, "%s", ls->ls_name); diff --git a/fs/dlm/member.c b/fs/dlm/member.c index 862640a36d5..476557b5492 100644 --- a/fs/dlm/member.c +++ b/fs/dlm/member.c @@ -616,13 +616,13 @@ int dlm_ls_stop(struct dlm_ls *ls) down_write(&ls->ls_recv_active); /* - * Abort any recovery that's in progress (see RECOVERY_STOP, + * Abort any recovery that's in progress (see RECOVER_STOP, * dlm_recovery_stopped()) and tell any other threads running in the * dlm to quit any processing (see RUNNING, dlm_locking_stopped()). */ spin_lock(&ls->ls_recover_lock); - set_bit(LSFL_RECOVERY_STOP, &ls->ls_flags); + set_bit(LSFL_RECOVER_STOP, &ls->ls_flags); new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags); ls->ls_recover_seq++; spin_unlock(&ls->ls_recover_lock); @@ -642,12 +642,16 @@ int dlm_ls_stop(struct dlm_ls *ls) * when recovery is complete. */ - if (new) - down_write(&ls->ls_in_recovery); + if (new) { + set_bit(LSFL_RECOVER_DOWN, &ls->ls_flags); + wake_up_process(ls->ls_recoverd_task); + wait_event(ls->ls_recover_lock_wait, + test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags)); + } /* * The recoverd suspend/resume makes sure that dlm_recoverd (if - * running) has noticed RECOVERY_STOP above and quit processing the + * running) has noticed RECOVER_STOP above and quit processing the * previous recovery. */ @@ -709,7 +713,8 @@ int dlm_ls_start(struct dlm_ls *ls) kfree(rv_old); } - dlm_recoverd_kick(ls); + set_bit(LSFL_RECOVER_WORK, &ls->ls_flags); + wake_up_process(ls->ls_recoverd_task); return 0; fail: diff --git a/fs/dlm/rcom.c b/fs/dlm/rcom.c index 87f1a56eab3..9d61947d473 100644 --- a/fs/dlm/rcom.c +++ b/fs/dlm/rcom.c @@ -581,7 +581,7 @@ void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid) spin_lock(&ls->ls_recover_lock); status = ls->ls_recover_status; - stop = test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags); + stop = test_bit(LSFL_RECOVER_STOP, &ls->ls_flags); seq = ls->ls_recover_seq; spin_unlock(&ls->ls_recover_lock); diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c index 88ce65ff021..32f9f8926ec 100644 --- a/fs/dlm/recoverd.c +++ b/fs/dlm/recoverd.c @@ -41,6 +41,7 @@ static int enable_locking(struct dlm_ls *ls, uint64_t seq) set_bit(LSFL_RUNNING, &ls->ls_flags); /* unblocks processes waiting to enter the dlm */ up_write(&ls->ls_in_recovery); + clear_bit(LSFL_RECOVER_LOCK, &ls->ls_flags); error = 0; } spin_unlock(&ls->ls_recover_lock); @@ -262,7 +263,7 @@ static void do_ls_recovery(struct dlm_ls *ls) rv = ls->ls_recover_args; ls->ls_recover_args = NULL; if (rv && ls->ls_recover_seq == rv->seq) - clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags); + clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags); spin_unlock(&ls->ls_recover_lock); if (rv) { @@ -282,26 +283,34 @@ static int dlm_recoverd(void *arg) return -1; } + down_write(&ls->ls_in_recovery); + set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags); + wake_up(&ls->ls_recover_lock_wait); + while (!kthread_should_stop()) { set_current_state(TASK_INTERRUPTIBLE); - if (!test_bit(LSFL_WORK, &ls->ls_flags)) + if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) && + !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) schedule(); set_current_state(TASK_RUNNING); - if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags)) + if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) { + down_write(&ls->ls_in_recovery); + set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags); + wake_up(&ls->ls_recover_lock_wait); + } + + if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags)) do_ls_recovery(ls); } + if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags)) + up_write(&ls->ls_in_recovery); + dlm_put_lockspace(ls); return 0; } -void dlm_recoverd_kick(struct dlm_ls *ls) -{ - set_bit(LSFL_WORK, &ls->ls_flags); - wake_up_process(ls->ls_recoverd_task); -} - int dlm_recoverd_start(struct dlm_ls *ls) { struct task_struct *p; diff --git a/fs/dlm/recoverd.h b/fs/dlm/recoverd.h index 866657c5d69..8856079733f 100644 --- a/fs/dlm/recoverd.h +++ b/fs/dlm/recoverd.h @@ -14,7 +14,6 @@ #ifndef __RECOVERD_DOT_H__ #define __RECOVERD_DOT_H__ -void dlm_recoverd_kick(struct dlm_ls *ls); void dlm_recoverd_stop(struct dlm_ls *ls); int dlm_recoverd_start(struct dlm_ls *ls); void dlm_recoverd_suspend(struct dlm_ls *ls); -- cgit v1.2.3