Commit 52d60f8e authored by Jeff Layton's avatar Jeff Layton Committed by Ilya Dryomov
Browse files

ceph: eliminate session->s_gen_ttl_lock 



Turn s_cap_gen field into an atomic_t, and just rely on the fact that we
hold the s_mutex when changing the s_cap_ttl field.

Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarLuis Henriques <lhenriques@suse.de>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 7e65624d

fs/ceph/caps.c

+6 −9
Original line number Diff line number Diff line
@@ -645,9 +645,7 @@ void ceph_add_cap(struct inode *inode, 
	dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,

	     session->s_mds, cap_id, ceph_cap_string(issued), seq);



	spin_lock(&session->s_gen_ttl_lock);

	gen = session->s_cap_gen;

	spin_unlock(&session->s_gen_ttl_lock);

	gen = atomic_read(&session->s_cap_gen);



	cap = __get_cap_for_mds(ci, mds);

	if (!cap) {
@@ -785,10 +783,8 @@ static int __cap_is_valid(struct ceph_cap *cap) 
	unsigned long ttl;

	u32 gen;



	spin_lock(&cap->session->s_gen_ttl_lock);

	gen = cap->session->s_cap_gen;

	gen = atomic_read(&cap->session->s_cap_gen);

	ttl = cap->session->s_cap_ttl;

	spin_unlock(&cap->session->s_gen_ttl_lock);



	if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {

		dout("__cap_is_valid %p cap %p issued %s "
@@ -1182,7 +1178,8 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release) 
	 * s_cap_gen while session is in the reconnect state.

	 */

	if (queue_release &&

	    (!session->s_cap_reconnect || cap->cap_gen == session->s_cap_gen)) {

	    (!session->s_cap_reconnect ||

	     cap->cap_gen == atomic_read(&session->s_cap_gen))) {

		cap->queue_release = 1;

		if (removed) {

			__ceph_queue_cap_release(session, cap);
@@ -3288,7 +3285,7 @@ static void handle_cap_grant(struct inode *inode, 
	u64 size = le64_to_cpu(grant->size);

	u64 max_size = le64_to_cpu(grant->max_size);

	unsigned char check_caps = 0;

	bool was_stale = cap->cap_gen < session->s_cap_gen;

	bool was_stale = cap->cap_gen < atomic_read(&session->s_cap_gen);

	bool wake = false;

	bool writeback = false;

	bool queue_trunc = false;
@@ -3340,7 +3337,7 @@ static void handle_cap_grant(struct inode *inode, 
	}



	/* side effects now are allowed */

	cap->cap_gen = session->s_cap_gen;

	cap->cap_gen = atomic_read(&session->s_cap_gen);

	cap->seq = seq;



	__check_cap_issue(ci, cap, newcaps);

fs/ceph/dir.c

+1 −3
Original line number Diff line number Diff line
@@ -1548,10 +1548,8 @@ static bool __dentry_lease_is_valid(struct ceph_dentry_info *di) 
		u32 gen;

		unsigned long ttl;



		spin_lock(&session->s_gen_ttl_lock);

		gen = session->s_cap_gen;

		gen = atomic_read(&session->s_cap_gen);

		ttl = session->s_cap_ttl;

		spin_unlock(&session->s_gen_ttl_lock);



		if (di->lease_gen == gen &&

		    time_before(jiffies, ttl) &&

fs/ceph/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -1124,7 +1124,7 @@ static void __update_dentry_lease(struct inode *dir, struct dentry *dentry, 
		return;

	}



	if (di->lease_gen == session->s_cap_gen &&

	if (di->lease_gen == atomic_read(&session->s_cap_gen) &&

	    time_before(ttl, di->time))

		return;  /* we already have a newer lease. */
@@ -1135,7 +1135,7 @@ static void __update_dentry_lease(struct inode *dir, struct dentry *dentry, 


	if (!di->lease_session)

		di->lease_session = ceph_get_mds_session(session);

	di->lease_gen = session->s_cap_gen;

	di->lease_gen = atomic_read(&session->s_cap_gen);

	di->lease_seq = le32_to_cpu(lease->seq);

	di->lease_renew_after = half_ttl;

	di->lease_renew_from = 0;

fs/ceph/mds_client.c

+6 −11
Original line number Diff line number Diff line
@@ -749,8 +749,7 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc, 


	ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);



	spin_lock_init(&s->s_gen_ttl_lock);

	s->s_cap_gen = 1;

	atomic_set(&s->s_cap_gen, 1);

	s->s_cap_ttl = jiffies - 1;



	spin_lock_init(&s->s_cap_lock);
@@ -1763,7 +1762,7 @@ static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap, 
		ci->i_requested_max_size = 0;

		spin_unlock(&ci->i_ceph_lock);

	} else if (ev == RENEWCAPS) {

		if (cap->cap_gen < cap->session->s_cap_gen) {

		if (cap->cap_gen < atomic_read(&cap->session->s_cap_gen)) {

			/* mds did not re-issue stale cap */

			spin_lock(&ci->i_ceph_lock);

			cap->issued = cap->implemented = CEPH_CAP_PIN;
@@ -3501,10 +3500,8 @@ static void handle_session(struct ceph_mds_session *session, 
	case CEPH_SESSION_STALE:

		pr_info("mds%d caps went stale, renewing\n",

			session->s_mds);

		spin_lock(&session->s_gen_ttl_lock);

		session->s_cap_gen++;

		atomic_inc(&session->s_cap_gen);

		session->s_cap_ttl = jiffies - 1;

		spin_unlock(&session->s_gen_ttl_lock);

		send_renew_caps(mdsc, session);

		break;
@@ -3773,7 +3770,7 @@ static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap, 
	cap->seq = 0;        /* reset cap seq */

	cap->issue_seq = 0;  /* and issue_seq */

	cap->mseq = 0;       /* and migrate_seq */

	cap->cap_gen = cap->session->s_cap_gen;

	cap->cap_gen = atomic_read(&cap->session->s_cap_gen);



	/* These are lost when the session goes away */

	if (S_ISDIR(inode->i_mode)) {
@@ -4013,9 +4010,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, 
	dout("session %p state %s\n", session,

	     ceph_session_state_name(session->s_state));



	spin_lock(&session->s_gen_ttl_lock);

	session->s_cap_gen++;

	spin_unlock(&session->s_gen_ttl_lock);

	atomic_inc(&session->s_cap_gen);



	spin_lock(&session->s_cap_lock);

	/* don't know if session is readonly */
@@ -4346,7 +4341,7 @@ static void handle_lease(struct ceph_mds_client *mdsc, 


	case CEPH_MDS_LEASE_RENEW:

		if (di->lease_session == session &&

		    di->lease_gen == session->s_cap_gen &&

		    di->lease_gen == atomic_read(&session->s_cap_gen) &&

		    di->lease_renew_from &&

		    di->lease_renew_after == 0) {

			unsigned long duration =

fs/ceph/mds_client.h

+2 −4
Original line number Diff line number Diff line
@@ -186,10 +186,8 @@ struct ceph_mds_session { 


	struct ceph_auth_handshake s_auth;



	/* protected by s_gen_ttl_lock */

	spinlock_t        s_gen_ttl_lock;

	u32               s_cap_gen;  /* inc each time we get mds stale msg */

	unsigned long     s_cap_ttl;  /* when session caps expire */

	atomic_t          s_cap_gen;  /* inc each time we get mds stale msg */

	unsigned long     s_cap_ttl;  /* when session caps expire. protected by s_mutex */



	/* protected by s_cap_lock */

	spinlock_t        s_cap_lock;