Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (28 commits)
  ceph: update discussion list address in MAINTAINERS
  ceph: some documentations fixes
  ceph: fix use after free on mds __unregister_request
  ceph: avoid loaded term 'OSD' in documention
  ceph: fix possible double-free of mds request reference
  ceph: fix session check on mds reply
  ceph: handle kmalloc() failure
  ceph: propagate mds session allocation failures to caller
  ceph: make write_begin wait propagate ERESTARTSYS
  ceph: fix snap rebuild condition
  ceph: avoid reopening osd connections when address hasn't changed
  ceph: rename r_sent_stamp r_stamp
  ceph: fix connection fault con_work reentrancy problem
  ceph: prevent dup stale messages to console for restarting mds
  ceph: fix pg pool decoding from incremental osdmap update
  ceph: fix mds sync() race with completing requests
  ceph: only release unused caps with mds requests
  ceph: clean up handle_cap_grant, handle_caps wrt session mutex
  ceph: fix session locking in handle_caps, ceph_check_caps
  ceph: drop unnecessary WARN_ON in caps migration
  ...

12 files changed, 182 insertions, 91 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 23bb0ceabe31..ce8ef6107727 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -919,6 +919,10 @@ static int context_is_writeable_or_written(struct inode *inode,
 /*
  * We are only allowed to write into/dirty the page if the page is
  * clean, or already dirty within the same snap context.
+ *
+ * called with page locked.
+ * return success with page locked,
+ * or any failure (incl -EAGAIN) with page unlocked.
  */
 static int ceph_update_writeable_page(struct file *file,
                             loff_t pos, unsigned len,
@@ -961,9 +965,11 @@ retry_locked:
                         snapc = ceph_get_snap_context((void *)page->private);
                         unlock_page(page);
                         ceph_queue_writeback(inode);
-                        wait_event_interruptible(ci->i_cap_wq,
+                        r = wait_event_interruptible(ci->i_cap_wq,
                                context_is_writeable_or_written(inode, snapc));
                         ceph_put_snap_context(snapc);
+                        if (r == -ERESTARTSYS)
+                                return r;
                         return -EAGAIN;
                 }
 
@@ -1035,7 +1041,7 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
         int r;
 
         do {
-                /* get a page*/
+                /* get a page */
                 page = grab_cache_page_write_begin(mapping, index, 0);
                 if (!page)
                         return -ENOMEM;
diff --git a/fs/ceph/auth_x.c b/fs/ceph/auth_x.c
index f0318427b6da..8d8a84964763 100644
--- a/fs/ceph/auth_x.c
+++ b/fs/ceph/auth_x.c
@@ -28,6 +28,12 @@ static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
         return (ac->want_keys & xi->have_keys) == ac->want_keys;
 }
 
+static int ceph_x_encrypt_buflen(int ilen)
+{
+        return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
+                sizeof(u32);
+}
+
 static int ceph_x_encrypt(struct ceph_crypto_key *secret,
                           void *ibuf, int ilen, void *obuf, size_t olen)
 {
@@ -150,6 +156,11 @@ static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
                 struct timespec validity;
                 struct ceph_crypto_key old_key;
                 void *tp, *tpend;
+                struct ceph_timespec new_validity;
+                struct ceph_crypto_key new_session_key;
+                struct ceph_buffer *new_ticket_blob;
+                unsigned long new_expires, new_renew_after;
+                u64 new_secret_id;
 
                 ceph_decode_need(&p, end, sizeof(u32) + 1, bad);
 
@@ -182,16 +193,16 @@ static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
                         goto bad;
 
                 memcpy(&old_key, &th->session_key, sizeof(old_key));
-                ret = ceph_crypto_key_decode(&th->session_key, &dp, dend);
+                ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
                 if (ret)
                         goto out;
 
-                ceph_decode_copy(&dp, &th->validity, sizeof(th->validity));
-                ceph_decode_timespec(&validity, &th->validity);
-                th->expires = get_seconds() + validity.tv_sec;
-                th->renew_after = th->expires - (validity.tv_sec / 4);
-                dout(" expires=%lu renew_after=%lu\n", th->expires,
-                     th->renew_after);
+                ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
+                ceph_decode_timespec(&validity, &new_validity);
+                new_expires = get_seconds() + validity.tv_sec;
+                new_renew_after = new_expires - (validity.tv_sec / 4);
+                dout(" expires=%lu renew_after=%lu\n", new_expires,
+                     new_renew_after);
 
                 /* ticket blob for service */
                 ceph_decode_8_safe(&p, end, is_enc, bad);
@@ -216,10 +227,21 @@ static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
                 dout(" ticket blob is %d bytes\n", dlen);
                 ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
                 struct_v = ceph_decode_8(&tp);
-                th->secret_id = ceph_decode_64(&tp);
-                ret = ceph_decode_buffer(&th->ticket_blob, &tp, tpend);
+                new_secret_id = ceph_decode_64(&tp);
+                ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
                 if (ret)
                         goto out;
+
+                /* all is well, update our ticket */
+                ceph_crypto_key_destroy(&th->session_key);
+                if (th->ticket_blob)
+                        ceph_buffer_put(th->ticket_blob);
+                th->session_key = new_session_key;
+                th->ticket_blob = new_ticket_blob;
+                th->validity = new_validity;
+                th->secret_id = new_secret_id;
+                th->expires = new_expires;
+                th->renew_after = new_renew_after;
                 dout(" got ticket service %d (%s) secret_id %lld len %d\n",
                      type, ceph_entity_type_name(type), th->secret_id,
                      (int)th->ticket_blob->vec.iov_len);
@@ -242,7 +264,7 @@ static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
                                    struct ceph_x_ticket_handler *th,
                                    struct ceph_x_authorizer *au)
 {
-        int len;
+        int maxlen;
         struct ceph_x_authorize_a *msg_a;
         struct ceph_x_authorize_b msg_b;
         void *p, *end;
@@ -253,15 +275,15 @@ static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
         dout("build_authorizer for %s %p\n",
              ceph_entity_type_name(th->service), au);
 
-        len = sizeof(*msg_a) + sizeof(msg_b) + sizeof(u32) +
-                ticket_blob_len + 16;
-        dout("  need len %d\n", len);
-        if (au->buf && au->buf->alloc_len < len) {
+        maxlen = sizeof(*msg_a) + sizeof(msg_b) +
+                ceph_x_encrypt_buflen(ticket_blob_len);
+        dout("  need len %d\n", maxlen);
+        if (au->buf && au->buf->alloc_len < maxlen) {
                 ceph_buffer_put(au->buf);
                 au->buf = NULL;
         }
         if (!au->buf) {
-                au->buf = ceph_buffer_new(len, GFP_NOFS);
+                au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
                 if (!au->buf)
                         return -ENOMEM;
         }
@@ -296,6 +318,7 @@ static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
         au->buf->vec.iov_len = p - au->buf->vec.iov_base;
         dout(" built authorizer nonce %llx len %d\n", au->nonce,
              (int)au->buf->vec.iov_len);
+        BUG_ON(au->buf->vec.iov_len > maxlen);
         return 0;
 
 out_buf:
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index db122bb357b8..7d0a0d0adc18 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1407,6 +1407,7 @@ static int try_nonblocking_invalidate(struct inode *inode)
  */
 void ceph_check_caps(struct ceph_inode_info *ci, int flags,
                      struct ceph_mds_session *session)
+        __releases(session->s_mutex)
 {
         struct ceph_client *client = ceph_inode_to_client(&ci->vfs_inode);
         struct ceph_mds_client *mdsc = &client->mdsc;
@@ -1414,7 +1415,6 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
         struct ceph_cap *cap;
         int file_wanted, used;
         int took_snap_rwsem = 0;             /* true if mdsc->snap_rwsem held */
-        int drop_session_lock = session ? 0 : 1;
         int issued, implemented, want, retain, revoking, flushing = 0;
         int mds = -1;   /* keep track of how far we've gone through i_caps list
                            to avoid an infinite loop on retry */
@@ -1639,7 +1639,7 @@ ack:
         if (queue_invalidate)
                 ceph_queue_invalidate(inode);
 
-        if (session && drop_session_lock)
+        if (session)
                 mutex_unlock(&session->s_mutex);
         if (took_snap_rwsem)
                 up_read(&mdsc->snap_rwsem);
@@ -2195,18 +2195,19 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
  * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
  * actually be a revocation if it specifies a smaller cap set.)
  *
- * caller holds s_mutex.
+ * caller holds s_mutex and i_lock, we drop both.
+ *
  * return value:
  *  0 - ok
  *  1 - check_caps on auth cap only (writeback)
  *  2 - check_caps (ack revoke)
  */
-static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
-                            struct ceph_mds_session *session,
-                            struct ceph_cap *cap,
-                            struct ceph_buffer *xattr_buf)
+static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
+                             struct ceph_mds_session *session,
+                             struct ceph_cap *cap,
+                             struct ceph_buffer *xattr_buf)
         __releases(inode->i_lock)
-
+        __releases(session->s_mutex)
 {
         struct ceph_inode_info *ci = ceph_inode(inode);
         int mds = session->s_mds;
@@ -2216,7 +2217,7 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
         u64 size = le64_to_cpu(grant->size);
         u64 max_size = le64_to_cpu(grant->max_size);
         struct timespec mtime, atime, ctime;
-        int reply = 0;
+        int check_caps = 0;
         int wake = 0;
         int writeback = 0;
         int revoked_rdcache = 0;
@@ -2329,11 +2330,12 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                 if ((used & ~newcaps) & CEPH_CAP_FILE_BUFFER)
                         writeback = 1; /* will delay ack */
                 else if (dirty & ~newcaps)
-                        reply = 1;     /* initiate writeback in check_caps */
+                        check_caps = 1;  /* initiate writeback in check_caps */
                 else if (((used & ~newcaps) & CEPH_CAP_FILE_CACHE) == 0 ||
                            revoked_rdcache)
-                        reply = 2;     /* send revoke ack in check_caps */
+                        check_caps = 2;     /* send revoke ack in check_caps */
                 cap->issued = newcaps;
+                cap->implemented |= newcaps;
         } else if (cap->issued == newcaps) {
                 dout("caps unchanged: %s -> %s\n",
                      ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
@@ -2346,6 +2348,7 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                                               * pending revocation */
                 wake = 1;
         }
+        BUG_ON(cap->issued & ~cap->implemented);
 
         spin_unlock(&inode->i_lock);
         if (writeback)
@@ -2359,7 +2362,14 @@ static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                 ceph_queue_invalidate(inode);
         if (wake)
                 wake_up(&ci->i_cap_wq);
-        return reply;
+
+        if (check_caps == 1)
+                ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
+                                session);
+        else if (check_caps == 2)
+                ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
+        else
+                mutex_unlock(&session->s_mutex);
 }
 
 /*
@@ -2548,9 +2558,8 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
                         ci->i_cap_exporting_issued = cap->issued;
                 }
                 __ceph_remove_cap(cap);
-        } else {
-                WARN_ON(!cap);
         }
+        /* else, we already released it */
 
         spin_unlock(&inode->i_lock);
 }
@@ -2621,9 +2630,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
         u64 cap_id;
         u64 size, max_size;
         u64 tid;
-        int check_caps = 0;
         void *snaptrace;
-        int r;
 
         dout("handle_caps from mds%d\n", mds);
 
@@ -2668,8 +2675,9 @@ void ceph_handle_caps(struct ceph_mds_session *session,
         case CEPH_CAP_OP_IMPORT:
                 handle_cap_import(mdsc, inode, h, session,
                                   snaptrace, le32_to_cpu(h->snap_trace_len));
-                check_caps = 1; /* we may have sent a RELEASE to the old auth */
-                goto done;
+                ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY,
+                                session);
+                goto done_unlocked;
         }
 
         /* the rest require a cap */
@@ -2686,16 +2694,8 @@ void ceph_handle_caps(struct ceph_mds_session *session,
         switch (op) {
         case CEPH_CAP_OP_REVOKE:
         case CEPH_CAP_OP_GRANT:
-                r = handle_cap_grant(inode, h, session, cap, msg->middle);
-                if (r == 1)
-                        ceph_check_caps(ceph_inode(inode),
-                                        CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
-                                        session);
-                else if (r == 2)
-                        ceph_check_caps(ceph_inode(inode),
-                                        CHECK_CAPS_NODELAY,
-                                        session);
-                break;
+                handle_cap_grant(inode, h, session, cap, msg->middle);
+                goto done_unlocked;
 
         case CEPH_CAP_OP_FLUSH_ACK:
                 handle_cap_flush_ack(inode, tid, h, session, cap);
@@ -2713,9 +2713,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 
 done:
         mutex_unlock(&session->s_mutex);
-
-        if (check_caps)
-                ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY, NULL);
+done_unlocked:
         if (inode)
                 iput(inode);
         return;
@@ -2838,11 +2836,18 @@ int ceph_encode_inode_release(void **p, struct inode *inode,
         struct ceph_cap *cap;
         struct ceph_mds_request_release *rel = *p;
         int ret = 0;
-
-        dout("encode_inode_release %p mds%d drop %s unless %s\n", inode,
-             mds, ceph_cap_string(drop), ceph_cap_string(unless));
+        int used = 0;
 
         spin_lock(&inode->i_lock);
+        used = __ceph_caps_used(ci);
+
+        dout("encode_inode_release %p mds%d used %s drop %s unless %s\n", inode,
+             mds, ceph_cap_string(used), ceph_cap_string(drop),
+             ceph_cap_string(unless));
+
+        /* only drop unused caps */
+        drop &= ~used;
+
         cap = __get_cap_for_mds(ci, mds);
         if (cap && __cap_is_valid(cap)) {
                 if (force ||
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 5107384ee029..8a9116e15b70 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -288,8 +288,10 @@ more:
                         CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
 
                 /* discard old result, if any */
-                if (fi->last_readdir)
+                if (fi->last_readdir) {
                         ceph_mdsc_put_request(fi->last_readdir);
+                        fi->last_readdir = NULL;
+                }
 
                 /* requery frag tree, as the frag topology may have changed */
                 frag = ceph_choose_frag(ceph_inode(inode), frag, NULL, NULL);
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 7abe1aed819b..aca82d55cc53 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -378,6 +378,22 @@ void ceph_destroy_inode(struct inode *inode)
 
         ceph_queue_caps_release(inode);
 
+        /*
+         * we may still have a snap_realm reference if there are stray
+         * caps in i_cap_exporting_issued or i_snap_caps.
+         */
+        if (ci->i_snap_realm) {
+                struct ceph_mds_client *mdsc =
+                        &ceph_client(ci->vfs_inode.i_sb)->mdsc;
+                struct ceph_snap_realm *realm = ci->i_snap_realm;
+
+                dout(" dropping residual ref to snap realm %p\n", realm);
+                spin_lock(&realm->inodes_with_caps_lock);
+                list_del_init(&ci->i_snap_realm_item);
+                spin_unlock(&realm->inodes_with_caps_lock);
+                ceph_put_snap_realm(mdsc, realm);
+        }
+
         kfree(ci->i_symlink);
         while ((n = rb_first(&ci->i_fragtree)) != NULL) {
                 frag = rb_entry(n, struct ceph_inode_frag, node);
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index a2600101ec22..5c7920be6420 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -328,6 +328,8 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
         struct ceph_mds_session *s;
 
         s = kzalloc(sizeof(*s), GFP_NOFS);
+        if (!s)
+                return ERR_PTR(-ENOMEM);
         s->s_mdsc = mdsc;
         s->s_mds = mds;
         s->s_state = CEPH_MDS_SESSION_NEW;
@@ -529,7 +531,7 @@ static void __unregister_request(struct ceph_mds_client *mdsc,
 {
         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
         rb_erase(&req->r_node, &mdsc->request_tree);
-        ceph_mdsc_put_request(req);
+        RB_CLEAR_NODE(&req->r_node);
 
         if (req->r_unsafe_dir) {
                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
@@ -538,6 +540,8 @@ static void __unregister_request(struct ceph_mds_client *mdsc,
                 list_del_init(&req->r_unsafe_dir_item);
                 spin_unlock(&ci->i_unsafe_lock);
         }
+
+        ceph_mdsc_put_request(req);
 }
 
 /*
@@ -862,6 +866,7 @@ static int send_renew_caps(struct ceph_mds_client *mdsc,
         if (time_after_eq(jiffies, session->s_cap_ttl) &&
             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
                 pr_info("mds%d caps stale\n", session->s_mds);
+        session->s_renew_requested = jiffies;
 
         /* do not try to renew caps until a recovering mds has reconnected
          * with its clients. */
@@ -874,7 +879,6 @@ static int send_renew_caps(struct ceph_mds_client *mdsc,
 
         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
                 ceph_mds_state_name(state));
-        session->s_renew_requested = jiffies;
         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
                                  ++session->s_renew_seq);
         if (IS_ERR(msg))
@@ -1566,8 +1570,13 @@ static int __do_request(struct ceph_mds_client *mdsc,
 
         /* get, open session */
         session = __ceph_lookup_mds_session(mdsc, mds);
-        if (!session)
+        if (!session) {
                 session = register_session(mdsc, mds);
+                if (IS_ERR(session)) {
+                        err = PTR_ERR(session);
+                        goto finish;
+                }
+        }
         dout("do_request mds%d session %p state %s\n", mds, session,
              session_state_name(session->s_state));
         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
@@ -1770,7 +1779,7 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
         dout("handle_reply %p\n", req);
 
         /* correct session? */
-        if (!req->r_session && req->r_session != session) {
+        if (req->r_session != session) {
                 pr_err("mdsc_handle_reply got %llu on session mds%d"
                        " not mds%d\n", tid, session->s_mds,
                        req->r_session ? req->r_session->s_mds : -1);
@@ -2682,29 +2691,41 @@ void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
  */
 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
 {
-        struct ceph_mds_request *req = NULL;
+        struct ceph_mds_request *req = NULL, *nextreq;
         struct rb_node *n;
 
         mutex_lock(&mdsc->mutex);
         dout("wait_unsafe_requests want %lld\n", want_tid);
+restart:
         req = __get_oldest_req(mdsc);
         while (req && req->r_tid <= want_tid) {
+                /* find next request */
+                n = rb_next(&req->r_node);
+                if (n)
+                        nextreq = rb_entry(n, struct ceph_mds_request, r_node);
+                else
+                        nextreq = NULL;
                 if ((req->r_op & CEPH_MDS_OP_WRITE)) {
                         /* write op */
                         ceph_mdsc_get_request(req);
+                        if (nextreq)
+                                ceph_mdsc_get_request(nextreq);
                         mutex_unlock(&mdsc->mutex);
                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
                              req->r_tid, want_tid);
                         wait_for_completion(&req->r_safe_completion);
                         mutex_lock(&mdsc->mutex);
-                        n = rb_next(&req->r_node);
                         ceph_mdsc_put_request(req);
-                } else {
-                        n = rb_next(&req->r_node);
+                        if (!nextreq)
+                                break;  /* next dne before, so we're done! */
+                        if (RB_EMPTY_NODE(&nextreq->r_node)) {
+                                /* next request was removed from tree */
+                                ceph_mdsc_put_request(nextreq);
+                                goto restart;
+                        }
+                        ceph_mdsc_put_request(nextreq);  /* won't go away */
                 }
-                if (!n)
-                        break;
-                req = rb_entry(n, struct ceph_mds_request, r_node);
+                req = nextreq;
         }
         mutex_unlock(&mdsc->mutex);
         dout("wait_unsafe_requests done\n");
diff --git a/fs/ceph/messenger.c b/fs/ceph/messenger.c
index 781656a49bf8..a32f0f896d9f 100644
--- a/fs/ceph/messenger.c
+++ b/fs/ceph/messenger.c
@@ -366,6 +366,14 @@ void ceph_con_open(struct ceph_connection *con, struct ceph_entity_addr *addr)
 }
 
 /*
+ * return true if this connection ever successfully opened
+ */
+bool ceph_con_opened(struct ceph_connection *con)
+{
+        return con->connect_seq > 0;
+}
+
+/*
  * generic get/put
  */
 struct ceph_connection *ceph_con_get(struct ceph_connection *con)
@@ -830,13 +838,6 @@ static void prepare_read_connect(struct ceph_connection *con)
         con->in_base_pos = 0;
 }
 
-static void prepare_read_connect_retry(struct ceph_connection *con)
-{
-        dout("prepare_read_connect_retry %p\n", con);
-        con->in_base_pos = strlen(CEPH_BANNER) + sizeof(con->actual_peer_addr)
-                + sizeof(con->peer_addr_for_me);
-}
-
 static void prepare_read_ack(struct ceph_connection *con)
 {
         dout("prepare_read_ack %p\n", con);
@@ -1146,7 +1147,7 @@ static int process_connect(struct ceph_connection *con)
                 }
                 con->auth_retry = 1;
                 prepare_write_connect(con->msgr, con, 0);
-                prepare_read_connect_retry(con);
+                prepare_read_connect(con);
                 break;
 
         case CEPH_MSGR_TAG_RESETSESSION:
@@ -1843,8 +1844,6 @@ static void ceph_fault(struct ceph_connection *con)
                 goto out;
         }
 
-        clear_bit(BUSY, &con->state);  /* to avoid an improbable race */
-
         mutex_lock(&con->mutex);
         if (test_bit(CLOSED, &con->state))
                 goto out_unlock;
diff --git a/fs/ceph/messenger.h b/fs/ceph/messenger.h
index 4caaa5911110..a343dae73cdc 100644
--- a/fs/ceph/messenger.h
+++ b/fs/ceph/messenger.h
@@ -223,6 +223,7 @@ extern void ceph_con_init(struct ceph_messenger *msgr,
                           struct ceph_connection *con);
 extern void ceph_con_open(struct ceph_connection *con,
                           struct ceph_entity_addr *addr);
+extern bool ceph_con_opened(struct ceph_connection *con);
 extern void ceph_con_close(struct ceph_connection *con);
 extern void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg);
 extern void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg);
diff --git a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
index dbe63db9762f..c7b4dedaace6 100644
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -413,11 +413,22 @@ static void remove_old_osds(struct ceph_osd_client *osdc, int remove_all)
  */
 static int __reset_osd(struct ceph_osd_client *osdc, struct ceph_osd *osd)
 {
+        struct ceph_osd_request *req;
         int ret = 0;
 
         dout("__reset_osd %p osd%d\n", osd, osd->o_osd);
         if (list_empty(&osd->o_requests)) {
                 __remove_osd(osdc, osd);
+        } else if (memcmp(&osdc->osdmap->osd_addr[osd->o_osd],
+                          &osd->o_con.peer_addr,
+                          sizeof(osd->o_con.peer_addr)) == 0 &&
+                   !ceph_con_opened(&osd->o_con)) {
+                dout(" osd addr hasn't changed and connection never opened,"
+                     " letting msgr retry");
+                /* touch each r_stamp for handle_timeout()'s benfit */
+                list_for_each_entry(req, &osd->o_requests, r_osd_item)
+                        req->r_stamp = jiffies;
+                ret = -EAGAIN;
         } else {
                 ceph_con_close(&osd->o_con);
                 ceph_con_open(&osd->o_con, &osdc->osdmap->osd_addr[osd->o_osd]);
@@ -633,7 +644,7 @@ static int __send_request(struct ceph_osd_client *osdc,
         reqhead->flags |= cpu_to_le32(req->r_flags);  /* e.g., RETRY */
         reqhead->reassert_version = req->r_reassert_version;
 
-        req->r_sent_stamp = jiffies;
+        req->r_stamp = jiffies;
         list_move_tail(&osdc->req_lru, &req->r_req_lru_item);
 
         ceph_msg_get(req->r_request); /* send consumes a ref */
@@ -660,7 +671,7 @@ static void handle_timeout(struct work_struct *work)
         unsigned long timeout = osdc->client->mount_args->osd_timeout * HZ;
         unsigned long keepalive =
                 osdc->client->mount_args->osd_keepalive_timeout * HZ;
-        unsigned long last_sent = 0;
+        unsigned long last_stamp = 0;
         struct rb_node *p;
         struct list_head slow_osds;
 
@@ -697,12 +708,12 @@ static void handle_timeout(struct work_struct *work)
                 req = list_entry(osdc->req_lru.next, struct ceph_osd_request,
                                  r_req_lru_item);
 
-                if (time_before(jiffies, req->r_sent_stamp + timeout))
+                if (time_before(jiffies, req->r_stamp + timeout))
                         break;
 
-                BUG_ON(req == last_req && req->r_sent_stamp == last_sent);
+                BUG_ON(req == last_req && req->r_stamp == last_stamp);
                 last_req = req;
-                last_sent = req->r_sent_stamp;
+                last_stamp = req->r_stamp;
 
                 osd = req->r_osd;
                 BUG_ON(!osd);
@@ -718,7 +729,7 @@ static void handle_timeout(struct work_struct *work)
          */
         INIT_LIST_HEAD(&slow_osds);
         list_for_each_entry(req, &osdc->req_lru, r_req_lru_item) {
-                if (time_before(jiffies, req->r_sent_stamp + keepalive))
+                if (time_before(jiffies, req->r_stamp + keepalive))
                         break;
 
                 osd = req->r_osd;
@@ -862,7 +873,9 @@ static int __kick_requests(struct ceph_osd_client *osdc,
 
         dout("kick_requests osd%d\n", kickosd ? kickosd->o_osd : -1);
         if (kickosd) {
-                __reset_osd(osdc, kickosd);
+                err = __reset_osd(osdc, kickosd);
+                if (err == -EAGAIN)
+                        return 1;
         } else {
                 for (p = rb_first(&osdc->osds); p; p = n) {
                         struct ceph_osd *osd =
@@ -913,7 +926,7 @@ static int __kick_requests(struct ceph_osd_client *osdc,
 
 kick:
                 dout("kicking %p tid %llu osd%d\n", req, req->r_tid,
-                     req->r_osd->o_osd);
+                     req->r_osd ? req->r_osd->o_osd : -1);
                 req->r_flags |= CEPH_OSD_FLAG_RETRY;
                 err = __send_request(osdc, req);
                 if (err) {
diff --git a/fs/ceph/osd_client.h b/fs/ceph/osd_client.h
index 1b1a3ca43afc..b0759911e7c3 100644
--- a/fs/ceph/osd_client.h
+++ b/fs/ceph/osd_client.h
@@ -70,7 +70,7 @@ struct ceph_osd_request {
 
         char              r_oid[40];          /* object name */
         int               r_oid_len;
-        unsigned long     r_sent_stamp;
+        unsigned long     r_stamp;            /* send OR check time */
         bool              r_resend;           /* msg send failed, needs retry */
 
         struct ceph_file_layout r_file_layout;
diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index b83f2692b835..d82fe87c2a6e 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -480,6 +480,14 @@ static struct ceph_pg_pool_info *__lookup_pg_pool(struct rb_root *root, int id)
         return NULL;
 }
 
+void __decode_pool(void **p, struct ceph_pg_pool_info *pi)
+{
+        ceph_decode_copy(p, &pi->v, sizeof(pi->v));
+        calc_pg_masks(pi);
+        *p += le32_to_cpu(pi->v.num_snaps) * sizeof(u64);
+        *p += le32_to_cpu(pi->v.num_removed_snap_intervals) * sizeof(u64) * 2;
+}
+
 /*
  * decode a full map.
  */
@@ -526,12 +534,8 @@ struct ceph_osdmap *osdmap_decode(void **p, void *end)
                                    ev, CEPH_PG_POOL_VERSION);
                         goto bad;
                 }
-                ceph_decode_copy(p, &pi->v, sizeof(pi->v));
+                __decode_pool(p, pi);
                 __insert_pg_pool(&map->pg_pools, pi);
-                calc_pg_masks(pi);
-                *p += le32_to_cpu(pi->v.num_snaps) * sizeof(u64);
-                *p += le32_to_cpu(pi->v.num_removed_snap_intervals)
-                        * sizeof(u64) * 2;
         }
         ceph_decode_32_safe(p, end, map->pool_max, bad);
 
@@ -714,8 +718,7 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
                         pi->id = pool;
                         __insert_pg_pool(&map->pg_pools, pi);
                 }
-                ceph_decode_copy(p, &pi->v, sizeof(pi->v));
-                calc_pg_masks(pi);
+                __decode_pool(p, pi);
         }
 
         /* old_pool */
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index bf2a5f3846a4..df04e210a055 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -314,9 +314,9 @@ static int build_snap_context(struct ceph_snap_realm *realm)
            because we rebuild_snap_realms() works _downward_ in
            hierarchy after each update.) */
         if (realm->cached_context &&
-            realm->cached_context->seq <= realm->seq &&
+            realm->cached_context->seq == realm->seq &&
             (!parent ||
-             realm->cached_context->seq <= parent->cached_context->seq)) {
+             realm->cached_context->seq >= parent->cached_context->seq)) {
                 dout("build_snap_context %llx %p: %p seq %lld (%d snaps)"
                      " (unchanged)\n",
                      realm->ino, realm, realm->cached_context,
@@ -818,7 +818,9 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
                          * queued (again) by ceph_update_snap_trace()
                          * below.  Queue it _now_, under the old context.
                          */
+                        spin_lock(&realm->inodes_with_caps_lock);
                         list_del_init(&ci->i_snap_realm_item);
+                        spin_unlock(&realm->inodes_with_caps_lock);
                         spin_unlock(&inode->i_lock);
 
                         ceph_queue_cap_snap(ci,