1 files changed, 45 insertions, 30 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index f3496db4bb3e..94c026bba2c2 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -657,6 +657,9 @@ void ceph_add_cap(struct inode *inode,
 		session->s_nr_caps++;
 		spin_unlock(&session->s_cap_lock);
 	} else {
+		if (cap->cap_gen < session->s_cap_gen)
+			cap->issued = cap->implemented = CEPH_CAP_PIN;
+
 		/*
 		 * auth mds of the inode changed. we received the cap export
 		 * message, but still haven't received the cap import message.
@@ -1855,14 +1858,17 @@ retry_locked:
 			retain |= CEPH_CAP_ANY;       /* be greedy */
 		} else if (S_ISDIR(inode->i_mode) &&
 			   (issued & CEPH_CAP_FILE_SHARED) &&
-			    __ceph_dir_is_complete(ci)) {
+			   __ceph_dir_is_complete(ci)) {
 			/*
 			 * If a directory is complete, we want to keep
 			 * the exclusive cap. So that MDS does not end up
 			 * revoking the shared cap on every create/unlink
 			 * operation.
 			 */
-			want = CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_EXCL;
+			if (IS_RDONLY(inode))
+				want = CEPH_CAP_ANY_SHARED;
+			else
+				want = CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_EXCL;
 			retain |= want;
 		} else {
 
@@ -1970,8 +1976,7 @@ retry_locked:
 			goto ack;
 
 		/* things we might delay */
-		if ((cap->issued & ~retain) == 0 &&
-		    cap->mds_wanted == want)
+		if ((cap->issued & ~retain) == 0)
 			continue;     /* nope, all good */
 
 		if (no_delay)
@@ -3048,7 +3053,8 @@ static void handle_cap_grant(struct inode *inode,
 	int used, wanted, dirty;
 	u64 size = le64_to_cpu(grant->size);
 	u64 max_size = le64_to_cpu(grant->max_size);
-	int check_caps = 0;
+	unsigned char check_caps = 0;
+	bool was_stale = cap->cap_gen < session->s_cap_gen;
 	bool wake = false;
 	bool writeback = false;
 	bool queue_trunc = false;
@@ -3063,21 +3069,6 @@ static void handle_cap_grant(struct inode *inode,
 
 
 	/*
-	 * auth mds of the inode changed. we received the cap export message,
-	 * but still haven't received the cap import message. handle_cap_export
-	 * updated the new auth MDS' cap.
-	 *
-	 * "ceph_seq_cmp(seq, cap->seq) <= 0" means we are processing a message
-	 * that was sent before the cap import message. So don't remove caps.
-	 */
-	if (ceph_seq_cmp(seq, cap->seq) <= 0) {
-		WARN_ON(cap != ci->i_auth_cap);
-		WARN_ON(cap->cap_id != le64_to_cpu(grant->cap_id));
-		seq = cap->seq;
-		newcaps |= cap->issued;
-	}
-
-	/*
 	 * If CACHE is being revoked, and we have no dirty buffers,
 	 * try to invalidate (once).  (If there are dirty buffers, we
 	 * will invalidate _after_ writeback.)
@@ -3096,6 +3087,24 @@ static void handle_cap_grant(struct inode *inode,
 		}
 	}
 
+	if (was_stale)
+		cap->issued = cap->implemented = CEPH_CAP_PIN;
+
+	/*
+	 * auth mds of the inode changed. we received the cap export message,
+	 * but still haven't received the cap import message. handle_cap_export
+	 * updated the new auth MDS' cap.
+	 *
+	 * "ceph_seq_cmp(seq, cap->seq) <= 0" means we are processing a message
+	 * that was sent before the cap import message. So don't remove caps.
+	 */
+	if (ceph_seq_cmp(seq, cap->seq) <= 0) {
+		WARN_ON(cap != ci->i_auth_cap);
+		WARN_ON(cap->cap_id != le64_to_cpu(grant->cap_id));
+		seq = cap->seq;
+		newcaps |= cap->issued;
+	}
+
 	/* side effects now are allowed */
 	cap->cap_gen = session->s_cap_gen;
 	cap->seq = seq;
@@ -3200,13 +3209,20 @@ static void handle_cap_grant(struct inode *inode,
 	     ceph_cap_string(wanted),
 	     ceph_cap_string(used),
 	     ceph_cap_string(dirty));
-	if (wanted != le32_to_cpu(grant->wanted)) {
-		dout("mds wanted %s -> %s\n",
-		     ceph_cap_string(le32_to_cpu(grant->wanted)),
-		     ceph_cap_string(wanted));
-		/* imported cap may not have correct mds_wanted */
-		if (le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT)
-			check_caps = 1;
+
+	if ((was_stale || le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT) &&
+	    (wanted & ~(cap->mds_wanted | newcaps))) {
+		/*
+		 * If mds is importing cap, prior cap messages that update
+		 * 'wanted' may get dropped by mds (migrate seq mismatch).
+		 *
+		 * We don't send cap message to update 'wanted' if what we
+		 * want are already issued. If mds revokes caps, cap message
+		 * that releases caps also tells mds what we want. But if
+		 * caps got revoked by mds forcedly (session stale). We may
+		 * haven't told mds what we want.
+		 */
+		check_caps = 1;
 	}
 
 	/* revocation, grant, or no-op? */
@@ -3539,9 +3555,9 @@ retry:
 		goto out_unlock;
 
 	if (target < 0) {
-		__ceph_remove_cap(cap, false);
-		if (!ci->i_auth_cap)
+		if (cap->mds_wanted | cap->issued)
 			ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
+		__ceph_remove_cap(cap, false);
 		goto out_unlock;
 	}
 
@@ -3569,7 +3585,6 @@ retry:
 			tcap->cap_id = t_cap_id;
 			tcap->seq = t_seq - 1;
 			tcap->issue_seq = t_seq - 1;
-			tcap->mseq = t_mseq;
 			tcap->issued |= issued;
 			tcap->implemented |= issued;
 			if (cap == ci->i_auth_cap)