libceph: support for checking on status of watch

Implement ceph_osdc_watch_check() to be able to check on status of
watch.  Note that the time it takes for a watch/notify event to get
delivered through the notify_wq is taken into account.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Ilya Dryomov 2016-04-28 16:07:27 +02:00
parent 1907920324
commit b07d3c4bd7
2 changed files with 55 additions and 1 deletions

View File

@ -213,6 +213,8 @@ struct ceph_osd_linger_request {
struct ceph_osd_request *reg_req;
struct ceph_osd_request *ping_req;
unsigned long ping_sent;
unsigned long watch_valid_thru;
struct list_head pending_lworks;
struct ceph_osd_request_target t;
u32 last_force_resend;
@ -417,5 +419,7 @@ int ceph_osdc_notify(struct ceph_osd_client *osdc,
u32 timeout,
struct page ***preply_pages,
size_t *preply_len);
int ceph_osdc_watch_check(struct ceph_osd_client *osdc,
struct ceph_osd_linger_request *lreq);
#endif

View File

@ -1746,6 +1746,7 @@ static void linger_release(struct kref *kref)
WARN_ON(!RB_EMPTY_NODE(&lreq->node));
WARN_ON(!RB_EMPTY_NODE(&lreq->osdc_node));
WARN_ON(!list_empty(&lreq->scan_item));
WARN_ON(!list_empty(&lreq->pending_lworks));
WARN_ON(lreq->osd);
if (lreq->reg_req)
@ -1783,6 +1784,7 @@ linger_alloc(struct ceph_osd_client *osdc)
RB_CLEAR_NODE(&lreq->node);
RB_CLEAR_NODE(&lreq->osdc_node);
INIT_LIST_HEAD(&lreq->scan_item);
INIT_LIST_HEAD(&lreq->pending_lworks);
init_completion(&lreq->reg_commit_wait);
init_completion(&lreq->notify_finish_wait);
@ -1890,6 +1892,8 @@ static void cancel_linger_request(struct ceph_osd_request *req)
struct linger_work {
struct work_struct work;
struct ceph_osd_linger_request *lreq;
struct list_head pending_item;
unsigned long queued_stamp;
union {
struct {
@ -1916,6 +1920,7 @@ static struct linger_work *lwork_alloc(struct ceph_osd_linger_request *lreq,
return NULL;
INIT_WORK(&lwork->work, workfn);
INIT_LIST_HEAD(&lwork->pending_item);
lwork->lreq = linger_get(lreq);
return lwork;
@ -1925,6 +1930,10 @@ static void lwork_free(struct linger_work *lwork)
{
struct ceph_osd_linger_request *lreq = lwork->lreq;
mutex_lock(&lreq->lock);
list_del(&lwork->pending_item);
mutex_unlock(&lreq->lock);
linger_put(lreq);
kfree(lwork);
}
@ -1935,6 +1944,10 @@ static void lwork_queue(struct linger_work *lwork)
struct ceph_osd_client *osdc = lreq->osdc;
verify_lreq_locked(lreq);
WARN_ON(!list_empty(&lwork->pending_item));
lwork->queued_stamp = jiffies;
list_add_tail(&lwork->pending_item, &lreq->pending_lworks);
queue_work(osdc->notify_wq, &lwork->work);
}
@ -2116,7 +2129,9 @@ static void linger_ping_cb(struct ceph_osd_request *req)
__func__, lreq, lreq->linger_id, req->r_result, lreq->ping_sent,
lreq->last_error);
if (lreq->register_gen == req->r_ops[0].watch.gen) {
if (req->r_result && !lreq->last_error) {
if (!req->r_result) {
lreq->watch_valid_thru = lreq->ping_sent;
} else if (!lreq->last_error) {
lreq->last_error = normalize_watch_error(req->r_result);
queue_watch_error(lreq);
}
@ -3316,6 +3331,7 @@ ceph_osdc_watch(struct ceph_osd_client *osdc,
lreq->wcb = wcb;
lreq->errcb = errcb;
lreq->data = data;
lreq->watch_valid_thru = jiffies;
ceph_oid_copy(&lreq->t.base_oid, oid);
ceph_oloc_copy(&lreq->t.base_oloc, oloc);
@ -3577,6 +3593,40 @@ out_put_lreq:
}
EXPORT_SYMBOL(ceph_osdc_notify);
/*
* Return the number of milliseconds since the watch was last
* confirmed, or an error. If there is an error, the watch is no
* longer valid, and should be destroyed with ceph_osdc_unwatch().
*/
int ceph_osdc_watch_check(struct ceph_osd_client *osdc,
struct ceph_osd_linger_request *lreq)
{
unsigned long stamp, age;
int ret;
down_read(&osdc->lock);
mutex_lock(&lreq->lock);
stamp = lreq->watch_valid_thru;
if (!list_empty(&lreq->pending_lworks)) {
struct linger_work *lwork =
list_first_entry(&lreq->pending_lworks,
struct linger_work,
pending_item);
if (time_before(lwork->queued_stamp, stamp))
stamp = lwork->queued_stamp;
}
age = jiffies - stamp;
dout("%s lreq %p linger_id %llu age %lu last_error %d\n", __func__,
lreq, lreq->linger_id, age, lreq->last_error);
/* we are truncating to msecs, so return a safe upper bound */
ret = lreq->last_error ?: 1 + jiffies_to_msecs(age);
mutex_unlock(&lreq->lock);
up_read(&osdc->lock);
return ret;
}
/*
* Call all pending notify callbacks - for use after a watch is
* unregistered, to make sure no more callbacks for it will be invoked