diff options
Diffstat (limited to 'fs/gfs2/glock.c')
| -rw-r--r-- | fs/gfs2/glock.c | 1611 |
1 files changed, 644 insertions, 967 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index d636b3e80f5d..519a54cc0b7b 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -45,21 +45,19 @@ struct gfs2_gl_hash_bucket { struct hlist_head hb_list; }; -struct glock_iter { - int hash; /* hash bucket index */ - struct gfs2_sbd *sdp; /* incore superblock */ - struct gfs2_glock *gl; /* current glock struct */ - struct seq_file *seq; /* sequence file for debugfs */ - char string[512]; /* scratch space */ +struct gfs2_glock_iter { + int hash; /* hash bucket index */ + struct gfs2_sbd *sdp; /* incore superblock */ + struct gfs2_glock *gl; /* current glock struct */ + char string[512]; /* scratch space */ }; typedef void (*glock_examiner) (struct gfs2_glock * gl); static int gfs2_dump_lockstate(struct gfs2_sbd *sdp); -static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl); -static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh); -static void gfs2_glock_drop_th(struct gfs2_glock *gl); -static void run_queue(struct gfs2_glock *gl); +static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); +#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0) +static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); static DECLARE_RWSEM(gfs2_umount_flush_sem); static struct dentry *gfs2_root; @@ -123,33 +121,6 @@ static inline rwlock_t *gl_lock_addr(unsigned int x) #endif /** - * relaxed_state_ok - is a requested lock compatible with the current lock mode? - * @actual: the current state of the lock - * @requested: the lock state that was requested by the caller - * @flags: the modifier flags passed in by the caller - * - * Returns: 1 if the locks are compatible, 0 otherwise - */ - -static inline int relaxed_state_ok(unsigned int actual, unsigned requested, - int flags) -{ - if (actual == requested) - return 1; - - if (flags & GL_EXACT) - return 0; - - if (actual == LM_ST_EXCLUSIVE && requested == LM_ST_SHARED) - return 1; - - if (actual != LM_ST_UNLOCKED && (flags & LM_FLAG_ANY)) - return 1; - - return 0; -} - -/** * gl_hash() - Turn glock number into hash bucket number * @lock: The glock number * @@ -211,17 +182,14 @@ static void gfs2_glock_hold(struct gfs2_glock *gl) int gfs2_glock_put(struct gfs2_glock *gl) { int rv = 0; - struct gfs2_sbd *sdp = gl->gl_sbd; write_lock(gl_lock_addr(gl->gl_hash)); if (atomic_dec_and_test(&gl->gl_ref)) { hlist_del(&gl->gl_list); write_unlock(gl_lock_addr(gl->gl_hash)); - gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED); - gfs2_assert(sdp, list_empty(&gl->gl_reclaim)); - gfs2_assert(sdp, list_empty(&gl->gl_holders)); - gfs2_assert(sdp, list_empty(&gl->gl_waiters1)); - gfs2_assert(sdp, list_empty(&gl->gl_waiters3)); + GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_UNLOCKED); + GLOCK_BUG_ON(gl, !list_empty(&gl->gl_reclaim)); + GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); glock_free(gl); rv = 1; goto out; @@ -281,16 +249,382 @@ static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp, return gl; } +/** + * may_grant - check if its ok to grant a new lock + * @gl: The glock + * @gh: The lock request which we wish to grant + * + * Returns: true if its ok to grant the lock + */ + +static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh) +{ + const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list); + if ((gh->gh_state == LM_ST_EXCLUSIVE || + gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head) + return 0; + if (gl->gl_state == gh->gh_state) + return 1; + if (gh->gh_flags & GL_EXACT) + return 0; + if (gh->gh_state == LM_ST_SHARED && gl->gl_state == LM_ST_EXCLUSIVE) + return 1; + if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY)) + return 1; + return 0; +} + +static void gfs2_holder_wake(struct gfs2_holder *gh) +{ + clear_bit(HIF_WAIT, &gh->gh_iflags); + smp_mb__after_clear_bit(); + wake_up_bit(&gh->gh_iflags, HIF_WAIT); +} + +/** + * do_promote - promote as many requests as possible on the current queue + * @gl: The glock + * + * Returns: true if there is a blocked holder at the head of the list + */ + +static int do_promote(struct gfs2_glock *gl) +{ + const struct gfs2_glock_operations *glops = gl->gl_ops; + struct gfs2_holder *gh, *tmp; + int ret; + +restart: + list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { + if (test_bit(HIF_HOLDER, &gh->gh_iflags)) + continue; + if (may_grant(gl, gh)) { + if (gh->gh_list.prev == &gl->gl_holders && + glops->go_lock) { + spin_unlock(&gl->gl_spin); + /* FIXME: eliminate this eventually */ + ret = glops->go_lock(gh); + spin_lock(&gl->gl_spin); + if (ret) { + gh->gh_error = ret; + list_del_init(&gh->gh_list); + gfs2_holder_wake(gh); + goto restart; + } + set_bit(HIF_HOLDER, &gh->gh_iflags); + gfs2_holder_wake(gh); + goto restart; + } + set_bit(HIF_HOLDER, &gh->gh_iflags); + gfs2_holder_wake(gh); + continue; + } + if (gh->gh_list.prev == &gl->gl_holders) + return 1; + break; + } + return 0; +} + +/** + * do_error - Something unexpected has happened during a lock request + * + */ + +static inline void do_error(struct gfs2_glock *gl, const int ret) +{ + struct gfs2_holder *gh, *tmp; + + list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { + if (test_bit(HIF_HOLDER, &gh->gh_iflags)) + continue; + if (ret & LM_OUT_ERROR) + gh->gh_error = -EIO; + else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) + gh->gh_error = GLR_TRYFAILED; + else + continue; + list_del_init(&gh->gh_list); + gfs2_holder_wake(gh); + } +} + +/** + * find_first_waiter - find the first gh that's waiting for the glock + * @gl: the glock + */ + +static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) +{ + struct gfs2_holder *gh; + + list_for_each_entry(gh, &gl->gl_holders, gh_list) { + if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) + return gh; + } + return NULL; +} + +/** + * state_change - record that the glock is now in a different state + * @gl: the glock + * @new_state the new state + * + */ + +static void state_change(struct gfs2_glock *gl, unsigned int new_state) +{ + int held1, held2; + + held1 = (gl->gl_state != LM_ST_UNLOCKED); + held2 = (new_state != LM_ST_UNLOCKED); + + if (held1 != held2) { + if (held2) + gfs2_glock_hold(gl); + else + gfs2_glock_put(gl); + } + + gl->gl_state = new_state; + gl->gl_tchange = jiffies; +} + +static void gfs2_demote_wake(struct gfs2_glock *gl) +{ + gl->gl_demote_state = LM_ST_EXCLUSIVE; + clear_bit(GLF_DEMOTE, &gl->gl_flags); + smp_mb__after_clear_bit(); + wake_up_bit(&gl->gl_flags, GLF_DEMOTE); +} + +/** + * finish_xmote - The DLM has replied to one of our lock requests + * @gl: The glock + * @ret: The status from the DLM + * + */ + +static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) +{ + const struct gfs2_glock_operations *glops = gl->gl_ops; + struct gfs2_holder *gh; + unsigned state = ret & LM_OUT_ST_MASK; + + spin_lock(&gl->gl_spin); + state_change(gl, state); + gh = find_first_waiter(gl); + + /* Demote to UN request arrived during demote to SH or DF */ + if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && + state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) + gl->gl_target = LM_ST_UNLOCKED; + + /* Check for state != intended state */ + if (unlikely(state != gl->gl_target)) { + if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { + /* move to back of queue and try next entry */ + if (ret & LM_OUT_CANCELED) { + if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0) + list_move_tail(&gh->gh_list, &gl->gl_holders); + gh = find_first_waiter(gl); + gl->gl_target = gh->gh_state; + goto retry; + } + /* Some error or failed "try lock" - report it */ + if ((ret & LM_OUT_ERROR) || + (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { + gl->gl_target = gl->gl_state; + do_error(gl, ret); + goto out; + } + } + switch(state) { + /* Unlocked due to conversion deadlock, try again */ + case LM_ST_UNLOCKED: +retry: + do_xmote(gl, gh, gl->gl_target); + break; + /* Conversion fails, unlock and try again */ + case LM_ST_SHARED: + case LM_ST_DEFERRED: + do_xmote(gl, gh, LM_ST_UNLOCKED); + break; + default: /* Everything else */ + printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state); + GLOCK_BUG_ON(gl, 1); + } + spin_unlock(&gl->gl_spin); + gfs2_glock_put(gl); + return; + } + + /* Fast path - we got what we asked for */ + if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) + gfs2_demote_wake(gl); + if (state != LM_ST_UNLOCKED) { + if (glops->go_xmote_bh) { + int rv; + spin_unlock(&gl->gl_spin); + rv = glops->go_xmote_bh(gl, gh); + if (rv == -EAGAIN) + return; + spin_lock(&gl->gl_spin); + if (rv) { + do_error(gl, rv); + goto out; + } + } + do_promote(gl); + } +out: + clear_bit(GLF_LOCK, &gl->gl_flags); + spin_unlock(&gl->gl_spin); + gfs2_glock_put(gl); +} + +static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, + unsigned int cur_state, unsigned int req_state, + unsigned int flags) +{ + int ret = LM_OUT_ERROR; + if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) + ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state, + req_state, flags); + return ret; +} + +/** + * do_xmote - Calls the DLM to change the state of a lock + * @gl: The lock state + * @gh: The holder (only for promotes) + * @target: The target lock state + * + */ + +static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) +{ + const struct gfs2_glock_operations *glops = gl->gl_ops; + struct gfs2_sbd *sdp = gl->gl_sbd; + unsigned int lck_flags = gh ? gh->gh_flags : 0; + int ret; + + lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | + LM_FLAG_PRIORITY); + BUG_ON(gl->gl_state == target); + BUG_ON(gl->gl_state == gl->gl_target); + if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && + glops->go_inval) { + set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); + do_error(gl, 0); /* Fail queued try locks */ + } + spin_unlock(&gl->gl_spin); + if (glops->go_xmote_th) + glops->go_xmote_th(gl); + if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) + glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); + clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); + + gfs2_glock_hold(gl); + if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED || + gl->gl_state == LM_ST_DEFERRED) && + !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) + lck_flags |= LM_FLAG_TRY_1CB; + ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, target, lck_flags); + + if (!(ret & LM_OUT_ASYNC)) { + finish_xmote(gl, ret); + gfs2_glock_hold(gl); + if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) + gfs2_glock_put(gl); + } else { + GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC); + } + spin_lock(&gl->gl_spin); +} + +/** + * find_first_holder - find the first "holder" gh + * @gl: the glock + */ + +static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) +{ + struct gfs2_holder *gh; + + if (!list_empty(&gl->gl_holders)) { + gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); + if (test_bit(HIF_HOLDER, &gh->gh_iflags)) + return gh; + } + return NULL; +} + +/** + * run_queue - do all outstanding tasks related to a glock + * @gl: The glock in question + * @nonblock: True if we must not block in run_queue + * + */ + +static void run_queue(struct gfs2_glock *gl, const int nonblock) +{ + struct gfs2_holder *gh = NULL; + + if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) + return; + + GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); + + if (test_bit(GLF_DEMOTE, &gl->gl_flags) && + gl->gl_demote_state != gl->gl_state) { + if (find_first_holder(gl)) + goto out; + if (nonblock) + goto out_sched; + set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); + gl->gl_target = gl->gl_demote_state; + } else { + if (test_bit(GLF_DEMOTE, &gl->gl_flags)) + gfs2_demote_wake(gl); + if (do_promote(gl) == 0) + goto out; + gh = find_first_waiter(gl); + gl->gl_target = gh->gh_state; + if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) + do_error(gl, 0); /* Fail queued try locks */ + } + do_xmote(gl, gh, gl->gl_target); + return; + +out_sched: + gfs2_glock_hold(gl); + if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) + gfs2_glock_put(gl); +out: + clear_bit(GLF_LOCK, &gl->gl_flags); +} + static void glock_work_func(struct work_struct *work) { + unsigned long delay = 0; struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); + if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) + finish_xmote(gl, gl->gl_reply); spin_lock(&gl->gl_spin); - if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags)) - set_bit(GLF_DEMOTE, &gl->gl_flags); - run_queue(gl); + if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags)) { + unsigned long holdtime, now = jiffies; + holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; + if (time_before(now, holdtime)) + delay = holdtime - now; + set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags); + } + run_queue(gl, 0); spin_unlock(&gl->gl_spin); - gfs2_glock_put(gl); + if (!delay || + queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) + gfs2_glock_put(gl); } static int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name, @@ -342,12 +676,10 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, gl->gl_name = name; atomic_set(&gl->gl_ref, 1); gl->gl_state = LM_ST_UNLOCKED; + gl->gl_target = LM_ST_UNLOCKED; gl->gl_demote_state = LM_ST_EXCLUSIVE; gl->gl_hash = hash; - gl->gl_owner_pid = NULL; - gl->gl_ip = 0; gl->gl_ops = glops; - gl->gl_req_gh = NULL; gl->gl_stamp = jiffies; gl->gl_tchange = jiffies; gl->gl_object = NULL; @@ -447,13 +779,6 @@ void gfs2_holder_uninit(struct gfs2_holder *gh) gh->gh_ip = 0; } -static void gfs2_holder_wake(struct gfs2_holder *gh) -{ - clear_bit(HIF_WAIT, &gh->gh_iflags); - smp_mb__after_clear_bit(); - wake_up_bit(&gh->gh_iflags, HIF_WAIT); -} - static int just_schedule(void *word) { schedule(); @@ -466,14 +791,6 @@ static void wait_on_holder(struct gfs2_holder *gh) wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE); } -static void gfs2_demote_wake(struct gfs2_glock *gl) -{ - gl->gl_demote_state = LM_ST_EXCLUSIVE; - clear_bit(GLF_DEMOTE, &gl->gl_flags); - smp_mb__after_clear_bit(); - wake_up_bit(&gl->gl_flags, GLF_DEMOTE); -} - static void wait_on_demote(struct gfs2_glock *gl) { might_sleep(); @@ -481,217 +798,6 @@ static void wait_on_demote(struct gfs2_glock *gl) } /** - * rq_mutex - process a mutex request in the queue - * @gh: the glock holder - * - * Returns: 1 if the queue is blocked - */ - -static int rq_mutex(struct gfs2_holder *gh) -{ - struct gfs2_glock *gl = gh->gh_gl; - - list_del_init(&gh->gh_list); - /* gh->gh_error never examined. */ - set_bit(GLF_LOCK, &gl->gl_flags); - clear_bit(HIF_WAIT, &gh->gh_iflags); - smp_mb(); - wake_up_bit(&gh->gh_iflags, HIF_WAIT); - - return 1; -} - -/** - * rq_promote - process a promote request in the queue - * @gh: the glock holder - * - * Acquire a new inter-node lock, or change a lock state to more restrictive. - * - * Returns: 1 if the queue is blocked - */ - -static int rq_promote(struct gfs2_holder *gh) -{ - struct gfs2_glock *gl = gh->gh_gl; - - if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { - if (list_empty(&gl->gl_holders)) { - gl->gl_req_gh = gh; - set_bit(GLF_LOCK, &gl->gl_flags); - spin_unlock(&gl->gl_spin); - gfs2_glock_xmote_th(gh->gh_gl, gh); - spin_lock(&gl->gl_spin); - } - return 1; - } - - if (list_empty(&gl->gl_holders)) { - set_bit(HIF_FIRST, &gh->gh_iflags); - set_bit(GLF_LOCK, &gl->gl_flags); - } else { - struct gfs2_holder *next_gh; - if (gh->gh_state == LM_ST_EXCLUSIVE) - return 1; - next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder, - gh_list); - if (next_gh->gh_state == LM_ST_EXCLUSIVE) - return 1; - } - - list_move_tail(&gh->gh_list, &gl->gl_holders); - gh->gh_error = 0; - set_bit(HIF_HOLDER, &gh->gh_iflags); - - gfs2_holder_wake(gh); - - return 0; -} - -/** - * rq_demote - process a demote request in the queue - * @gh: the glock holder - * - * Returns: 1 if the queue is blocked - */ - -static int rq_demote(struct gfs2_glock *gl) -{ - if (!list_empty(&gl->gl_holders)) - return 1; - - if (gl->gl_state == gl->gl_demote_state || - gl->gl_state == LM_ST_UNLOCKED) { - gfs2_demote_wake(gl); - return 0; - } - - set_bit(GLF_LOCK, &gl->gl_flags); - set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); - - if (gl->gl_demote_state == LM_ST_UNLOCKED || - gl->gl_state != LM_ST_EXCLUSIVE) { - spin_unlock(&gl->gl_spin); - gfs2_glock_drop_th(gl); - } else { - spin_unlock(&gl->gl_spin); - gfs2_glock_xmote_th(gl, NULL); - } - - spin_lock(&gl->gl_spin); - clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); - - return 0; -} - -/** - * run_queue - process holder structures on a glock - * @gl: the glock - * - */ -static void run_queue(struct gfs2_glock *gl) -{ - struct gfs2_holder *gh; - int blocked = 1; - - for (;;) { - if (test_bit(GLF_LOCK, &gl->gl_flags)) - break; - - if (!list_empty(&gl->gl_waiters1)) { - gh = list_entry(gl->gl_waiters1.next, - struct gfs2_holder, gh_list); - blocked = rq_mutex(gh); - } else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { - blocked = rq_demote(gl); - if (test_bit(GLF_WAITERS2, &gl->gl_flags) && - !blocked) { - set_bit(GLF_DEMOTE, &gl->gl_flags); - gl->gl_demote_state = LM_ST_UNLOCKED; - } - clear_bit(GLF_WAITERS2, &gl->gl_flags); - } else if (!list_empty(&gl->gl_waiters3)) { - gh = list_entry(gl->gl_waiters3.next, - struct gfs2_holder, gh_list); - blocked = rq_promote(gh); - } else - break; - - if (blocked) - break; - } -} - -/** - * gfs2_glmutex_lock - acquire a local lock on a glock - * @gl: the glock - * - * Gives caller exclusive access to manipulate a glock structure. - */ - -static void gfs2_glmutex_lock(struct gfs2_glock *gl) -{ - spin_lock(&gl->gl_spin); - if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { - struct gfs2_holder gh; - - gfs2_holder_init(gl, 0, 0, &gh); - set_bit(HIF_WAIT, &gh.gh_iflags); - list_add_tail(&gh.gh_list, &gl->gl_waiters1); - spin_unlock(&gl->gl_spin); - wait_on_holder(&gh); - gfs2_holder_uninit(&gh); - } else { - gl->gl_owner_pid = get_pid(task_pid(current)); - gl->gl_ip = (unsigned long)__builtin_return_address(0); - spin_unlock(&gl->gl_spin); - } -} - -/** - * gfs2_glmutex_trylock - try to acquire a local lock on a glock - * @gl: the glock - * - * Returns: 1 if the glock is acquired - */ - -static int gfs2_glmutex_trylock(struct gfs2_glock *gl) -{ - int acquired = 1; - - spin_lock(&gl->gl_spin); - if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { - acquired = 0; - } else { - gl->gl_owner_pid = get_pid(task_pid(current)); - gl->gl_ip = (unsigned long)__builtin_return_address(0); - } - spin_unlock(&gl->gl_spin); - - return acquired; -} - -/** - * gfs2_glmutex_unlock - release a local lock on a glock - * @gl: the glock - * - */ - -static void gfs2_glmutex_unlock(struct gfs2_glock *gl) -{ - struct pid *pid; - - spin_lock(&gl->gl_spin); - clear_bit(GLF_LOCK, &gl->gl_flags); - pid = gl->gl_owner_pid; - gl->gl_owner_pid = NULL; - gl->gl_ip = 0; - run_queue(gl); - spin_unlock(&gl->gl_spin); - - put_pid(pid); -} - -/** * handle_callback - process a demote request * @gl: the glock * @state: the state the caller wants us to change to @@ -705,398 +811,45 @@ static void handle_callback(struct gfs2_glock *gl, unsigned int state, { int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE; - spin_lock(&gl->gl_spin); set_bit(bit, &gl->gl_flags); if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { gl->gl_demote_state = state; gl->gl_demote_time = jiffies; if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN && - gl->gl_object) { + gl->gl_object) gfs2_glock_schedule_for_reclaim(gl); - spin_unlock(&gl->gl_spin); - return; - } } else if (gl->gl_demote_state != LM_ST_UNLOCKED && gl->gl_demote_state != state) { - if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) - set_bit(GLF_WAITERS2, &gl->gl_flags); - else - gl->gl_demote_state = LM_ST_UNLOCKED; + gl->gl_demote_state = LM_ST_UNLOCKED; } - spin_unlock(&gl->gl_spin); } /** - * state_change - record that the glock is now in a different state - * @gl: the glock - * @new_state the new state - * - */ - -static void state_change(struct gfs2_glock *gl, unsigned int new_state) -{ - int held1, held2; - - held1 = (gl->gl_state != LM_ST_UNLOCKED); - held2 = (new_state != LM_ST_UNLOCKED); - - if (held1 != held2) { - if (held2) - gfs2_glock_hold(gl); - else - gfs2_glock_put(gl); - } - - gl->gl_state = new_state; - gl->gl_tchange = jiffies; -} - -/** - * drop_bh - Called after a lock module unlock completes - * @gl: the glock - * @ret: the return status - * - * Doesn't wake up the process waiting on the struct gfs2_holder (if any) - * Doesn't drop the reference on the glock the top half took out - * - */ - -static void drop_bh(struct gfs2_glock *gl, unsigned int ret) -{ - struct gfs2_sbd *sdp = gl->gl_sbd; - struct gfs2_holder *gh = gl->gl_req_gh; - - gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); - gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); - gfs2_assert_warn(sdp, !ret); - - state_change(gl, LM_ST_UNLOCKED); - - if (test_and_clear_bit(GLF_CONV_DEADLK, &gl->gl_flags)) { - spin_lock(&gl->gl_spin); - gh->gh_error = 0; - spin_unlock(&gl->gl_spin); - gfs2_glock_xmote_th(gl, gl->gl_req_gh); - gfs2_glock_put(gl); - return; - } - - spin_lock(&gl->gl_spin); - gfs2_demote_wake(gl); - clear_bit(GLF_LOCK, &gl->gl_flags); - spin_unlock(&gl->gl_spin); - gfs2_glock_put(gl); -} - -/** - * xmote_bh - Called after the lock module is done acquiring a lock - * @gl: The glock in question - * @ret: the int returned from the lock module - * - */ - -static void xmote_bh(struct gfs2_glock *gl, unsigned int ret) -{ - struct gfs2_sbd *sdp = gl->gl_sbd; - const struct gfs2_glock_operations *glops = gl->gl_ops; - struct gfs2_holder *gh = gl->gl_req_gh; - int op_done = 1; - - if (!gh && (ret & LM_OUT_ST_MASK) == LM_ST_UNLOCKED) { - drop_bh(gl, ret); - return; - } - - gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); - gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); - gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC)); - - state_change(gl, ret & LM_OUT_ST_MASK); - - /* Deal with each possible exit condition */ - - if (!gh) { - gl->gl_stamp = jiffies; - if (ret & LM_OUT_CANCELED) { - op_done = 0; - } else { - spin_lock(&gl->gl_spin); - if (gl->gl_state != gl->gl_demote_state) { - spin_unlock(&gl->gl_spin); - gfs2_glock_drop_th(gl); - gfs2_glock_put(gl); - return; - } - gfs2_demote_wake(gl); - spin_unlock(&gl->gl_spin); - } - } else { - spin_lock(&gl->gl_spin); - if (ret & LM_OUT_CONV_DEADLK) { - gh->gh_error = 0; - set_bit(GLF_CONV_DEADLK, &gl->gl_flags); - spin_unlock(&gl->gl_spin); - gfs2_glock_drop_th(gl); - gfs2_glock_put(gl); - return; - } - list_del_init(&gh->gh_list); - gh->gh_error = -EIO; - if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) - goto out; - gh->gh_error = GLR_CANCELED; - if (ret & LM_OUT_CANCELED) - goto out; - if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) { - list_add_tail(&gh->gh_list, &gl->gl_holders); - gh->gh_error = 0; - set_bit(HIF_HOLDER, &gh->gh_iflags); - set_bit(HIF_FIRST, &gh->gh_iflags); - op_done = 0; - goto out; - } - gh->gh_error = GLR_TRYFAILED; - if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) - goto out; - gh->gh_error = -EINVAL; - if (gfs2_assert_withdraw(sdp, 0) == -1) - fs_err(sdp, "ret = 0x%.8X\n", ret); -out: - spin_unlock(&gl->gl_spin); - } - - if (glops->go_xmote_bh) - glops->go_xmote_bh(gl); - - if (op_done) { - spin_lock(&gl->gl_spin); - gl->gl_req_gh = NULL; - clear_bit(GLF_LOCK, &gl->gl_flags); - spin_unlock(&gl->gl_spin); - } - - gfs2_glock_put(gl); - - if (gh) - gfs2_holder_wake(gh); -} - -static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock, - unsigned int cur_state, unsigned int req_state, - unsigned int flags) -{ - int ret = 0; - if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) - ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state, - req_state, flags); - return ret; -} - -/** - * gfs2_glock_xmote_th - Call into the lock module to acquire or change a glock - * @gl: The glock in question - * @state: the requested state - * @flags: modifier flags to the lock call - * - */ - -static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh) -{ - struct gfs2_sbd *sdp = gl->gl_sbd; - int flags = gh ? gh->gh_flags : 0; - unsigned state = gh ? gh->gh_state : gl->gl_demote_state; - const struct gfs2_glock_operations *glops = gl->gl_ops; - int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB | - LM_FLAG_NOEXP | LM_FLAG_ANY | - LM_FLAG_PRIORITY); - unsigned int lck_ret; - - if (glops->go_xmote_th) - glops->go_xmote_th(gl); - if (state == LM_ST_DEFERRED && glops->go_inval) - glops->go_inval(gl, DIO_METADATA); - - gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); - gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); - gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED); - gfs2_assert_warn(sdp, state != gl->gl_state); - - gfs2_glock_hold(gl); - - lck_ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, state, lck_flags); - - if (gfs2_assert_withdraw(sdp, !(lck_ret & LM_OUT_ERROR))) - return; - - if (lck_ret & LM_OUT_ASYNC) - gfs2_assert_warn(sdp, lck_ret == LM_OUT_ASYNC); - else - xmote_bh(gl, lck_ret); -} - -static unsigned int gfs2_lm_unlock(struct gfs2_sbd *sdp, void *lock, - unsigned int cur_state) -{ - int ret = 0; - if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) - ret = sdp->sd_lockstruct.ls_ops->lm_unlock(lock, cur_state); - return ret; -} - -/** - * gfs2_glock_drop_th - call into the lock module to unlock a lock - * @gl: the glock - * - */ - -static void gfs2_glock_drop_th(struct gfs2_glock *gl) -{ - struct gfs2_sbd *sdp = gl->gl_sbd; - const struct gfs2_glock_operations *glops = gl->gl_ops; - unsigned int ret; - - if (glops->go_xmote_th) - glops->go_xmote_th(gl); - if (glops->go_inval) - glops->go_inval(gl, DIO_METADATA); - - gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); - gfs2_assert_warn(sdp, list_empty(&gl->gl_holders)); - gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED); - - gfs2_glock_hold(gl); - - ret = gfs2_lm_unlock(sdp, gl->gl_lock, gl->gl_state); - - if (gfs2_assert_withdraw(sdp, !(ret & LM_OUT_ERROR))) - return; - - if (!ret) - drop_bh(gl, ret); - else - gfs2_assert_warn(sdp, ret == LM_OUT_ASYNC); -} - -/** - * do_cancels - cancel requests for locks stuck waiting on an expire flag - * @gh: the LM_FLAG_PRIORITY holder waiting to acquire the lock - * - * Don't cancel GL_NOCANCEL requests. - */ - -static void do_cancels(struct gfs2_holder *gh) -{ - struct gfs2_glock *gl = gh->gh_gl; - struct gfs2_sbd *sdp = gl->gl_sbd; - - spin_lock(&gl->gl_spin); - - while (gl->gl_req_gh != gh && - !test_bit(HIF_HOLDER, &gh->gh_iflags) && - !list_empty(&gh->gh_list)) { - if (!(gl->gl_req_gh && (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) { - spin_unlock(&gl->gl_spin); - if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) - sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock); - msleep(100); - spin_lock(&gl->gl_spin); - } else { - spin_unlock(&gl->gl_spin); - msleep(100); - spin_lock(&gl->gl_spin); - } - } - - spin_unlock(&gl->gl_spin); -} - -/** - * glock_wait_internal - wait on a glock acquisition + * gfs2_glock_wait - wait on a glock acquisition * @gh: the glock holder * * Returns: 0 on success */ -static int glock_wait_internal(struct gfs2_holder *gh) +int gfs2_glock_wait(struct gfs2_holder *gh) { - struct gfs2_glock *gl = gh->gh_gl; - struct gfs2_sbd *sdp = gl->gl_sbd; - const struct gfs2_glock_operations *glops = gl->gl_ops; - - if (test_bit(HIF_ABORTED, &gh->gh_iflags)) - return -EIO; - - if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { - spin_lock(&gl->gl_spin); - if (gl->gl_req_gh != gh && - !test_bit(HIF_HOLDER, &gh->gh_iflags) && - !list_empty(&gh->gh_list)) { - list_del_init(&gh->gh_list); - gh->gh_error = GLR_TRYFAILED; - run_queue(gl); - spin_unlock(&gl->gl_spin); - return gh->gh_error; - } - spin_unlock(&gl->gl_spin); - } - - if (gh->gh_flags & LM_FLAG_PRIORITY) - do_cancels(gh); - wait_on_holder(gh); - if (gh->gh_error) - return gh->gh_error; - - gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags)); - gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state, - gh->gh_flags)); - - if (test_bit(HIF_FIRST, &gh->gh_iflags)) { - gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags)); - - if (glops->go_lock) { - gh->gh_error = glops->go_lock(gh); - if (gh->gh_error) { - spin_lock(&gl->gl_spin); - list_del_init(&gh->gh_list); - spin_unlock(&gl->gl_spin); - } - } - - spin_lock(&gl->gl_spin); - gl->gl_req_gh = NULL; - clear_bit(GLF_LOCK, &gl->gl_flags); - run_queue(gl); - spin_unlock(&gl->gl_spin); - } - return gh->gh_error; } -static inline struct gfs2_holder * -find_holder_by_owner(struct list_head *head, struct pid *pid) -{ - struct gfs2_holder *gh; - - list_for_each_entry(gh, head, gh_list) { - if (gh->gh_owner_pid == pid) - return gh; - } - - return NULL; -} - -static void print_dbg(struct glock_iter *gi, const char *fmt, ...) +void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) { va_list args; va_start(args, fmt); - if (gi) { + if (seq) { + struct gfs2_glock_iter *gi = seq->private; vsprintf(gi->string, fmt, args); - seq_printf(gi->seq, gi->string); - } - else + seq_printf(seq, gi->string); + } else { + printk(KERN_ERR " "); vprintk(fmt, args); + } va_end(args); } @@ -1104,50 +857,75 @@ static void print_dbg(struct glock_iter *gi, const char *fmt, ...) * add_to_queue - Add a holder to the wait queue (but look for recursion) * @gh: the holder structure to add * + * Eventually we should move the recursive locking trap to a + * debugging option or something like that. This is the fast + * path and needs to have the minimum number of distractions. + * */ -static void add_to_queue(struct gfs2_holder *gh) +static inline void add_to_queue(struct gfs2_holder *gh) { struct gfs2_glock *gl = gh->gh_gl; - struct gfs2_holder *existing; + struct gfs2_sbd *sdp = gl->gl_sbd; + struct list_head *insert_pt = NULL; + struct gfs2_holder *gh2; + int try_lock = 0; BUG_ON(gh->gh_owner_pid == NULL); if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) BUG(); - if (!(gh->gh_flags & GL_FLOCK)) { - existing = find_holder_by_owner(&gl->gl_holders, - gh->gh_owner_pid); - if (existing) { - print_symbol(KERN_WARNING "original: %s\n", - existing->gh_ip); - printk(KERN_INFO "pid : %d\n", - pid_nr(existing->gh_owner_pid)); - printk(KERN_INFO "lock type : %d lock state : %d\n", - existing->gh_gl->gl_name.ln_type, - existing->gh_gl->gl_state); - print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); - printk(KERN_INFO "pid : %d\n", - pid_nr(gh->gh_owner_pid)); - printk(KERN_INFO "lock type : %d lock state : %d\n", - gl->gl_name.ln_type, gl->gl_state); - BUG(); - } - - existing = find_holder_by_owner(&gl->gl_waiters3, - gh->gh_owner_pid); - if (existing) { - print_symbol(KERN_WARNING "original: %s\n", - existing->gh_ip); - print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip); - BUG(); + if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { + if (test_bit(GLF_LOCK, &gl->gl_flags)) + try_lock = 1; + if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) + goto fail; + } + + list_for_each_entry(gh2, &gl->gl_holders, gh_list) { + if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && + (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK))) + goto trap_recursive; + if (try_lock && + !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) && + !may_grant(gl, gh)) { +fail: + gh->gh_error = GLR_TRYFAILED; + gfs2_holder_wake(gh); + return; } + if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) + continue; + if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt)) + insert_pt = &gh2->gh_list; + } + if (likely(insert_pt == NULL)) { + list_add_tail(&gh->gh_list, &gl->gl_holders); + if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY)) + goto do_cancel; + return; } + list_add_tail(&gh->gh_list, insert_pt); +do_cancel: + gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); + if (!(gh->gh_flags & LM_FLAG_PRIORITY)) { + spin_unlock(&gl->gl_spin); + sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock); + spin_lock(&gl->gl_spin); + } + return; - if (gh->gh_flags & LM_FLAG_PRIORITY) - list_add(&gh->gh_list, &gl->gl_waiters3); - else - list_add_tail(&gh->gh_list, &gl->gl_waiters3); +trap_recursive: + print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip); + printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid)); + printk(KERN_ERR "lock type: %d req lock state : %d\n", + gh2->gh_gl->gl_name.ln_type, gh2->gh_state); + print_symbol(KERN_ERR "new: %s\n", gh->gh_ip); + printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid)); + printk(KERN_ERR "lock type: %d req lock state : %d\n", + gh->gh_gl->gl_name.ln_type, gh->gh_state); + __dump_glock(NULL, gl); + BUG(); } /** @@ -1165,24 +943,16 @@ int gfs2_glock_nq(struct gfs2_holder *gh) struct gfs2_sbd *sdp = gl->gl_sbd; int error = 0; -restart: - if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { - set_bit(HIF_ABORTED, &gh->gh_iflags); + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) return -EIO; - } spin_lock(&gl->gl_spin); add_to_queue(gh); - run_queue(gl); + run_queue(gl, 1); spin_unlock(&gl->gl_spin); - if (!(gh->gh_flags & GL_ASYNC)) { - error = glock_wait_internal(gh); - if (error == GLR_CANCELED) { - msleep(100); - goto restart; - } - } + if (!(gh->gh_flags & GL_ASYNC)) + error = gfs2_glock_wait(gh); return error; } @@ -1196,48 +966,7 @@ restart: int gfs2_glock_poll(struct gfs2_holder *gh) { - struct gfs2_glock *gl = gh->gh_gl; - int ready = 0; - - spin_lock(&gl->gl_spin); - - if (test_bit(HIF_HOLDER, &gh->gh_iflags)) - ready = 1; - else if (list_empty(&gh->gh_list)) { - if (gh->gh_error == GLR_CANCELED) { - spin_unlock(&gl->gl_spin); - msleep(100); - if (gfs2_glock_nq(gh)) - return 1; - return 0; - } else - ready = 1; - } - - spin_unlock(&gl->gl_spin); - - return ready; -} - -/** - * gfs2_glock_wait - wait for a lock acquisition that ended in a GLR_ASYNC - * @gh: the holder structure - * - * Returns: 0, GLR_TRYFAILED, or errno on failure - */ - -int gfs2_glock_wait(struct gfs2_holder *gh) -{ - int error; - - error = glock_wait_internal(gh); - if (error == GLR_CANCELED) { - msleep(100); - gh->gh_flags &= ~GL_ASYNC; - error = gfs2_glock_nq(gh); - } - - return error; + return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; } /** @@ -1251,26 +980,30 @@ void gfs2_glock_dq(struct gfs2_holder *gh) struct gfs2_glock *gl = gh->gh_gl; const struct gfs2_glock_operations *glops = gl->gl_ops; unsigned delay = 0; + int fast_path = 0; + spin_lock(&gl->gl_spin); if (gh->gh_flags & GL_NOCACHE) handle_callback(gl, LM_ST_UNLOCKED, 0, 0); - gfs2_glmutex_lock(gl); - - spin_lock(&gl->gl_spin); list_del_init(&gh->gh_list); - - if (list_empty(&gl->gl_holders)) { + if (find_first_holder(gl) == NULL) { if (glops->go_unlock) { + GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags)); spin_unlock(&gl->gl_spin); glops->go_unlock(gh); spin_lock(&gl->gl_spin); + clear_bit(GLF_LOCK, &gl->gl_flags); } gl->gl_stamp = jiffies; + if (list_empty(&gl->gl_holders) && + !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && + !test_bit(GLF_DEMOTE, &gl->gl_flags)) + fast_path = 1; } - - clear_bit(GLF_LOCK, &gl->gl_flags); spin_unlock(&gl->gl_spin); + if (likely(fast_path)) + return; gfs2_glock_hold(gl); if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && @@ -1469,20 +1202,14 @@ int gfs2_lvb_hold(struct gfs2_glock *gl) { int error; - gfs2_glmutex_lock(gl); - if (!atomic_read(&gl->gl_lvb_count)) { error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb); - if (error) { - gfs2_glmutex_unlock(gl); + if (error) return error; - } gfs2_glock_hold(gl); } atomic_inc(&gl->gl_lvb_count); - gfs2_glmutex_unlock(gl); - return 0; } @@ -1497,8 +1224,6 @@ void gfs2_lvb_unhold(struct gfs2_glock *gl) struct gfs2_sbd *sdp = gl->gl_sbd; gfs2_glock_hold(gl); - gfs2_glmutex_lock(gl); - gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0); if (atomic_dec_and_test(&gl->gl_lvb_count)) { if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) @@ -1506,8 +1231,6 @@ void gfs2_lvb_unhold(struct gfs2_glock *gl) gl->gl_lvb = NULL; gfs2_glock_put(gl); } - - gfs2_glmutex_unlock(gl); gfs2_glock_put(gl); } @@ -1527,7 +1250,9 @@ static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name, if (time_before(now, holdtime)) delay = holdtime - now; + spin_lock(&gl->gl_spin); handle_callback(gl, state, 1, delay); + spin_unlock(&gl->gl_spin); if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0) gfs2_glock_put(gl); } @@ -1568,7 +1293,8 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data) gl = gfs2_glock_find(sdp, &async->lc_name); if (gfs2_assert_warn(sdp, gl)) return; - xmote_bh(gl, async->lc_ret); + gl->gl_reply = async->lc_ret; + set_bit(GLF_REPLY_PENDING, &gl->gl_flags); if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) gfs2_glock_put(gl); up_read(&gfs2_umount_flush_sem); @@ -1646,6 +1372,7 @@ void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl) void gfs2_reclaim_glock(struct gfs2_sbd *sdp) { struct gfs2_glock *gl; + int done_callback = 0; spin_lock(&sdp->sd_reclaim_lock); if (list_empty(&sdp->sd_reclaim_list)) { @@ -1660,14 +1387,16 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp) atomic_dec(&sdp->sd_reclaim_count); atomic_inc(&sdp->sd_reclaimed); - if (gfs2_glmutex_trylock(gl)) { - if (list_empty(&gl->gl_holders) && - gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) - handle_callback(gl, LM_ST_UNLOCKED, 0, 0); - gfs2_glmutex_unlock(gl); + spin_lock(&gl->gl_spin); + if (find_first_holder(gl) == NULL && + gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) { + handle_callback(gl, LM_ST_UNLOCKED, 0, 0); + done_callback = 1; } - - gfs2_glock_put(gl); + spin_unlock(&gl->gl_spin); + if (!done_callback || + queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) + gfs2_glock_put(gl); } /** @@ -1724,18 +1453,14 @@ static void scan_glock(struct gfs2_glock *gl) { if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) return; + if (test_bit(GLF_LOCK, &gl->gl_flags)) + return; - if (gfs2_glmutex_trylock(gl)) { - if (list_empty(&gl->gl_holders) && - gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) - goto out_schedule; - gfs2_glmutex_unlock(gl); - } - return; - -out_schedule: - gfs2_glmutex_unlock(gl); - gfs2_glock_schedule_for_reclaim(gl); + spin_lock(&gl->gl_spin); + if (find_first_holder(gl) == NULL && + gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) + gfs2_glock_schedule_for_reclaim(gl); + spin_unlock(&gl->gl_spin); } /** @@ -1760,12 +1485,13 @@ static void clear_glock(struct gfs2_glock *gl) spin_unlock(&sdp->sd_reclaim_lock); } - if (gfs2_glmutex_trylock(gl)) { - if (list_empty(&gl->gl_holders) && - gl->gl_state != LM_ST_UNLOCKED) - handle_callback(gl, LM_ST_UNLOCKED, 0, 0); - gfs2_glmutex_unlock(gl); - } + spin_lock(&gl->gl_spin); + if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED) + handle_callback(gl, LM_ST_UNLOCKED, 0, 0); + spin_unlock(&gl->gl_spin); + gfs2_glock_hold(gl); + if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) + gfs2_glock_put(gl); } /** @@ -1810,180 +1536,164 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait) } } -/* - * Diagnostic routines to help debug distributed deadlock - */ - -static void gfs2_print_symbol(struct glock_iter *gi, const char *fmt, - unsigned long address) +static const char *state2str(unsigned state) { - char buffer[KSYM_SYMBOL_LEN]; - - sprint_symbol(buffer, address); - print_dbg(gi, fmt, buffer); + switch(state) { + case LM_ST_UNLOCKED: + return "UN"; + case LM_ST_SHARED: + return "SH"; + case LM_ST_DEFERRED: + return "DF"; + case LM_ST_EXCLUSIVE: + return "EX"; + } + return "??"; +} + +static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags) +{ + char *p = buf; + if (flags & LM_FLAG_TRY) + *p++ = 't'; + if (flags & LM_FLAG_TRY_1CB) + *p++ = 'T'; + if (flags & LM_FLAG_NOEXP) + *p++ = 'e'; + if (flags & LM_FLAG_ANY) + *p++ = 'a'; + if (flags & LM_FLAG_PRIORITY) + *p++ = 'p'; + if (flags & GL_ASYNC) + *p++ = 'a'; + if (flags & GL_EXACT) + *p++ = 'E'; + if (flags & GL_ATIME) + *p++ = 'a'; + if (flags & GL_NOCACHE) + *p++ = 'c'; + if (test_bit(HIF_HOLDER, &iflags)) + *p++ = 'H'; + if (test_bit(HIF_WAIT, &iflags)) + *p++ = 'W'; + if (test_bit(HIF_FIRST, &iflags)) + *p++ = 'F'; + *p = 0; + return buf; } /** * dump_holder - print information about a glock holder - * @str: a string naming the type of holder + * @seq: the seq_file struct * @gh: the glock holder * * Returns: 0 on success, -ENOBUFS when we run out of space */ -static int dump_holder(struct glock_iter *gi, char *str, - struct gfs2_holder *gh) +static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh) { - unsigned int x; - struct task_struct *gh_owner; + struct task_struct *gh_owner = NULL; + char buffer[KSYM_SYMBOL_LEN]; + char flags_buf[32]; - print_dbg(gi, " %s\n", str); - if (gh->gh_owner_pid) { - print_dbg(gi, " owner = %ld ", - (long)pid_nr(gh->gh_owner_pid)); + sprint_symbol(buffer, gh->gh_ip); + if (gh->gh_owner_pid) gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); - if (gh_owner) - print_dbg(gi, "(%s)\n", gh_owner->comm); - else - print_dbg(gi, "(ended)\n"); - } else - print_dbg(gi, " owner = -1\n"); - print_dbg(gi, " gh_state = %u\n", gh->gh_state); - print_dbg(gi, " gh_flags ="); - for (x = 0; x < 32; x++) - if (gh->gh_flags & (1 << x)) - print_dbg(gi, " %u", x); - print_dbg(gi, " \n"); - print_dbg(gi, " error = %d\n", gh->gh_error); - print_dbg(gi, " gh_iflags ="); - for (x = 0; x < 32; x++) - if (test_bit(x, &gh->gh_iflags)) - print_dbg(gi, " %u", x); - print_dbg(gi, " \n"); - gfs2_print_symbol(gi, " initialized at: %s\n", gh->gh_ip); - + gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n", + state2str(gh->gh_state), + hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), + gh->gh_error, + gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, + gh_owner ? gh_owner->comm : "(ended)", buffer); return 0; } -/** - * dump_inode - print information about an inode - * @ip: the inode - * - * Returns: 0 on success, -ENOBUFS when we run out of space - */ - -static int dump_inode(struct glock_iter *gi, struct gfs2_inode *ip) -{ - unsigned int x; - - print_dbg(gi, " Inode:\n"); - print_dbg(gi, " num = %llu/%llu\n", - (unsigned long long)ip->i_no_formal_ino, - (unsigned long long)ip->i_no_addr); - print_dbg(gi, " type = %u\n", IF2DT(ip->i_inode.i_mode)); - print_dbg(gi, " i_flags ="); - for (x = 0; x < 32; x++) - if (test_bit(x, &ip->i_flags)) - print_dbg(gi, " %u", x); - print_dbg(gi, " \n"); - return 0; +static const char *gflags2str(char *buf, const unsigned long *gflags) +{ + char *p = buf; + if (test_bit(GLF_LOCK, gflags)) + *p++ = 'l'; + if (test_bit(GLF_STICKY, gflags)) + *p++ = 's'; + if (test_bit(GLF_DEMOTE, gflags)) + *p++ = 'D'; + if (test_bit(GLF_PENDING_DEMOTE, gflags)) + *p++ = 'd'; + if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) + *p++ = 'p'; + if (test_bit(GLF_DIRTY, gflags)) + *p++ = 'y'; + if (test_bit(GLF_LFLUSH, gflags)) + *p++ = 'f'; + if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) + *p++ = 'i'; + if (test_bit(GLF_REPLY_PENDING, gflags)) + *p++ = 'r'; + *p = 0; + return buf; } /** - * dump_glock - print information about a glock + * __dump_glock - print information about a glock + * @seq: The seq_file struct * @gl: the glock - * @count: where we are in the buffer + * + * The file format is as follows: + * One line per object, capital letters are used to indicate objects + * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, + * other objects are indented by a single space and follow the glock to + * which they are related. Fields are indicated by lower case letters + * followed by a colon and the field value, except for strings which are in + * [] so that its possible to see if they are composed of spaces for + * example. The field's are n = number (id of the object), f = flags, + * t = type, s = state, r = refcount, e = error, p = pid. * * Returns: 0 on success, -ENOBUFS when we run out of space */ -static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl) +static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl) { - struct gfs2_holder *gh; - unsigned int x; - int error = -ENOBUFS; - struct task_struct *gl_owner; + const struct gfs2_glock_operations *glops = gl->gl_ops; + unsigned long long dtime; + const struct gfs2_holder *gh; + char gflags_buf[32]; + int error = 0; - spin_lock(&gl->gl_spin); + dtime = jiffies - gl->gl_demote_time; + dtime *= 1000000/HZ; /* demote time in uSec */ + if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) + dtime = 0; + gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu l:%d a:%d r:%d\n", + state2str(gl->gl_state), + gl->gl_name.ln_type, + (unsigned long long)gl->gl_name.ln_number, + gflags2str(gflags_buf, &gl->gl_flags), + state2str(gl->gl_target), + state2str(gl->gl_demote_state), dtime, + atomic_read(&gl->gl_lvb_count), + atomic_read(&gl->gl_ail_count), + atomic_read(&gl->gl_ref)); - print_dbg(gi, "Glock 0x%p (%u, 0x%llx)\n", gl, gl->gl_name.ln_type, - (unsigned long long)gl->gl_name.ln_number); - print_dbg(gi, " gl_flags ="); - for (x = 0; x < 32; x++) { - if (test_bit(x, &gl->gl_flags)) - print_dbg(gi, " %u", x); - } - if (!test_bit(GLF_LOCK, &gl->gl_flags)) - print_dbg(gi, " (unlocked)"); - print_dbg(gi, " \n"); - print_dbg(gi, " gl_ref = %d\n", atomic_read(&gl->gl_ref)); - print_dbg(gi, " gl_state = %u\n", gl->gl_state); - if (gl->gl_owner_pid) { - gl_owner = pid_task(gl->gl_owner_pid, PIDTYPE_PID); - if (gl_owner) - print_dbg(gi, " gl_owner = pid %d (%s)\n", - pid_nr(gl->gl_owner_pid), gl_owner->comm); - else - print_dbg(gi, " gl_owner = %d (ended)\n", - pid_nr(gl->gl_owner_pid)); - } else - print_dbg(gi, " gl_owner = -1\n"); - print_dbg(gi, " gl_ip = %lu\n", gl->gl_ip); - print_dbg(gi, " req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no"); - print_dbg(gi, " lvb_count = %d\n", atomic_read(&gl->gl_lvb_count)); - print_dbg(gi, " object = %s\n", (gl->gl_object) ? "yes" : "no"); - print_dbg(gi, " reclaim = %s\n", - (list_empty(&gl->gl_reclaim)) ? "no" : "yes"); - if (gl->gl_aspace) - print_dbg(gi, " aspace = 0x%p nrpages = %lu\n", gl->gl_aspace, - gl->gl_aspace->i_mapping->nrpages); - else - print_dbg(gi, " aspace = no\n"); - print_dbg(gi, " ail = %d\n", atomic_read(&gl->gl_ail_count)); - if (gl->gl_req_gh) { - error = dump_holder(gi, "Request", gl->gl_req_gh); - if (error) - goto out; - } list_for_each_entry(gh, &gl->gl_holders, gh_list) { - error = dump_holder(gi, "Holder", gh); - if (error) - goto out; - } - list_for_each_entry(gh, &gl->gl_waiters1, gh_list) { - error = dump_holder(gi, "Waiter1", gh); - if (error) - goto out; - } - list_for_each_entry(gh, &gl->gl_waiters3, gh_list) { - error = dump_holder(gi, "Waiter3", gh); + error = dump_holder(seq, gh); if (error) goto out; } - if (test_bit(GLF_DEMOTE, &gl->gl_flags)) { - print_dbg(gi, " Demotion req to state %u (%llu uS ago)\n", - gl->gl_demote_state, (unsigned long long) - (jiffies - gl->gl_demote_time)*(1000000/HZ)); - } - if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object) { - if (!test_bit(GLF_LOCK, &gl->gl_flags) && - list_empty(&gl->gl_holders)) { - error = dump_inode(gi, gl->gl_object); - if (error) - goto out; - } else { - error = -ENOBUFS; - print_dbg(gi, " Inode: busy\n"); - } - } - - error = 0; - + if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) + error = glops->go_dump(seq, gl); out: - spin_unlock(&gl->gl_spin); return error; } +static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl) +{ + int ret; + spin_lock(&gl->gl_spin); + ret = __dump_glock(seq, gl); + spin_unlock(&gl->gl_spin); + return ret; +} + /** * gfs2_dump_lockstate - print out the current lockstate * @sdp: the filesystem @@ -2086,7 +1796,7 @@ void gfs2_glock_exit(void) module_param(scand_secs, uint, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs"); -static int gfs2_glock_iter_next(struct glock_iter *gi) +static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi) { struct gfs2_glock *gl; @@ -2104,7 +1814,7 @@ restart: gfs2_glock_put(gl); if (gl && gi->gl == NULL) gi->hash++; - while(gi->gl == NULL) { + while (gi->gl == NULL) { if (gi->hash >= GFS2_GL_HASH_SIZE) return 1; read_lock(gl_lock_addr(gi->hash)); @@ -2122,58 +1832,34 @@ restart: return 0; } -static void gfs2_glock_iter_free(struct glock_iter *gi) +static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi) { if (gi->gl) gfs2_glock_put(gi->gl); - kfree(gi); -} - -static struct glock_iter *gfs2_glock_iter_init(struct gfs2_sbd *sdp) -{ - struct glock_iter *gi; - - gi = kmalloc(sizeof (*gi), GFP_KERNEL); - if (!gi) - return NULL; - - gi->sdp = sdp; - gi->hash = 0; - gi->seq = NULL; gi->gl = NULL; - memset(gi->string, 0, sizeof(gi->string)); - - if (gfs2_glock_iter_next(gi)) { - gfs2_glock_iter_free(gi); - return NULL; - } - - return gi; } -static void *gfs2_glock_seq_start(struct seq_file *file, loff_t *pos) +static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) { - struct glock_iter *gi; + struct gfs2_glock_iter *gi = seq->private; loff_t n = *pos; - gi = gfs2_glock_iter_init(file->private); - if (!gi) - return NULL; + gi->hash = 0; - while(n--) { + do { if (gfs2_glock_iter_next(gi)) { gfs2_glock_iter_free(gi); return NULL; } - } + } while (n--); - return gi; + return gi->gl; } -static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr, +static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos) { - struct glock_iter *gi = iter_ptr; + struct gfs2_glock_iter *gi = seq->private; (*pos)++; @@ -2182,24 +1868,18 @@ static void *gfs2_glock_seq_next(struct seq_file *file, void *iter_ptr, return NULL; } - return gi; + return gi->gl; } -static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr) +static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) { - struct glock_iter *gi = iter_ptr; - if (gi) - gfs2_glock_iter_free(gi); + struct gfs2_glock_iter *gi = seq->private; + gfs2_glock_iter_free(gi); } -static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr) +static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) { - struct glock_iter *gi = iter_ptr; - - gi->seq = file; - dump_glock(gi, gi->gl); - - return 0; + return dump_glock(seq, iter_ptr); } static const struct seq_operations gfs2_glock_seq_ops = { @@ -2211,17 +1891,14 @@ static const struct seq_operations gfs2_glock_seq_ops = { static int gfs2_debugfs_open(struct inode *inode, struct file *file) { - struct seq_file *seq; - int ret; - - ret = seq_open(file, &gfs2_glock_seq_ops); - if (ret) - return ret; - - seq = file->private_data; - seq->private = inode->i_private; - - return 0; + int ret = seq_open_private(file, &gfs2_glock_seq_ops, + sizeof(struct gfs2_glock_iter)); + if (ret == 0) { + struct seq_file *seq = file->private_data; + struct gfs2_glock_iter *gi = seq->private; + gi->sdp = inode->i_private; + } + return ret; } static const struct file_operations gfs2_debug_fops = { @@ -2229,7 +1906,7 @@ static const struct file_operations gfs2_debug_fops = { .open = gfs2_debugfs_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release + .release = seq_release_private, }; int gfs2_create_debugfs_file(struct gfs2_sbd *sdp) |