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
  ...

1 files changed, 39 insertions, 34 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index db122bb..7d0a0d0 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 ||