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

Pull Ceph updates from Sage Weil:
 "This has a mix of bug fixes and cleanups.

  Alex's patch fixes a rare race in RBD.  Ilya's patches fix an ENOENT
  check when a second rbd image is mapped and a couple memory leaks.
  Zheng fixes several issues with fragmented directories and multiple
  MDSs.  Josh fixes a spin/sleep issue, and Josh and Guangliang's
  patches fix setting and unsetting RBD images read-only.

  Naturally there are several other cleanups mixed in for good measure"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (23 commits)
  rbd: only set disk to read-only once
  rbd: move calls that may sleep out of spin lock range
  rbd: add ioctl for rbd
  ceph: use truncate_pagecache() instead of truncate_inode_pages()
  ceph: include time stamp in every MDS request
  rbd: fix ida/idr memory leak
  rbd: use reference counts for image requests
  rbd: fix osd_request memory leak in __rbd_dev_header_watch_sync()
  rbd: make sure we have latest osdmap on 'rbd map'
  libceph: add ceph_monc_wait_osdmap()
  libceph: mon_get_version request infrastructure
  libceph: recognize poolop requests in debugfs
  ceph: refactor readpage_nounlock() to make the logic clearer
  mds: check cap ID when handling cap export message
  ceph: remember subtree root dirfrag's auth MDS
  ceph: introduce ceph_fill_fragtree()
  ceph: handle cap import atomically
  ceph: pre-allocate ceph_cap struct for ceph_add_cap()
  ceph: update inode fields according to issued caps
  rbd: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  ...

14 files changed, 670 insertions, 286 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4c95b503b09e..bbeb404b3a07 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -541,7 +541,6 @@ static int rbd_open(struct block_device *bdev, fmode_t mode)
 		return -ENOENT;
 
 	(void) get_device(&rbd_dev->dev);
-	set_device_ro(bdev, rbd_dev->mapping.read_only);
 
 	return 0;
 }
@@ -559,10 +558,76 @@ static void rbd_release(struct gendisk *disk, fmode_t mode)
 	put_device(&rbd_dev->dev);
 }
 
+static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
+{
+	int ret = 0;
+	int val;
+	bool ro;
+	bool ro_changed = false;
+
+	/* get_user() may sleep, so call it before taking rbd_dev->lock */
+	if (get_user(val, (int __user *)(arg)))
+		return -EFAULT;
+
+	ro = val ? true : false;
+	/* Snapshot doesn't allow to write*/
+	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
+		return -EROFS;
+
+	spin_lock_irq(&rbd_dev->lock);
+	/* prevent others open this device */
+	if (rbd_dev->open_count > 1) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (rbd_dev->mapping.read_only != ro) {
+		rbd_dev->mapping.read_only = ro;
+		ro_changed = true;
+	}
+
+out:
+	spin_unlock_irq(&rbd_dev->lock);
+	/* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
+	if (ret == 0 && ro_changed)
+		set_disk_ro(rbd_dev->disk, ro ? 1 : 0);
+
+	return ret;
+}
+
+static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
+			unsigned int cmd, unsigned long arg)
+{
+	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
+	int ret = 0;
+
+	switch (cmd) {
+	case BLKROSET:
+		ret = rbd_ioctl_set_ro(rbd_dev, arg);
+		break;
+	default:
+		ret = -ENOTTY;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
+				unsigned int cmd, unsigned long arg)
+{
+	return rbd_ioctl(bdev, mode, cmd, arg);
+}
+#endif /* CONFIG_COMPAT */
+
 static const struct block_device_operations rbd_bd_ops = {
 	.owner			= THIS_MODULE,
 	.open			= rbd_open,
 	.release		= rbd_release,
+	.ioctl			= rbd_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl		= rbd_compat_ioctl,
+#endif
 };
 
 /*
@@ -1382,6 +1447,13 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
 	kref_put(&obj_request->kref, rbd_obj_request_destroy);
 }
 
+static void rbd_img_request_get(struct rbd_img_request *img_request)
+{
+	dout("%s: img %p (was %d)\n", __func__, img_request,
+	     atomic_read(&img_request->kref.refcount));
+	kref_get(&img_request->kref);
+}
+
 static bool img_request_child_test(struct rbd_img_request *img_request);
 static void rbd_parent_request_destroy(struct kref *kref);
 static void rbd_img_request_destroy(struct kref *kref);
@@ -2142,6 +2214,7 @@ static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
 	img_request->next_completion = which;
 out:
 	spin_unlock_irq(&img_request->completion_lock);
+	rbd_img_request_put(img_request);
 
 	if (!more)
 		rbd_img_request_complete(img_request);
@@ -2242,6 +2315,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
 			goto out_unwind;
 		obj_request->osd_req = osd_req;
 		obj_request->callback = rbd_img_obj_callback;
+		rbd_img_request_get(img_request);
 
 		if (write_request) {
 			osd_req_op_alloc_hint_init(osd_req, which,
@@ -2872,56 +2946,55 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
 }
 
 /*
- * Request sync osd watch/unwatch.  The value of "start" determines
- * whether a watch request is being initiated or torn down.
+ * Initiate a watch request, synchronously.
  */
-static int __rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start)
+static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev)
 {
 	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
 	struct rbd_obj_request *obj_request;
 	int ret;
 
-	rbd_assert(start ^ !!rbd_dev->watch_event);
-	rbd_assert(start ^ !!rbd_dev->watch_request);
+	rbd_assert(!rbd_dev->watch_event);
+	rbd_assert(!rbd_dev->watch_request);
 
-	if (start) {
-		ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
-						&rbd_dev->watch_event);
-		if (ret < 0)
-			return ret;
-		rbd_assert(rbd_dev->watch_event != NULL);
-	}
+	ret = ceph_osdc_create_event(osdc, rbd_watch_cb, rbd_dev,
+				     &rbd_dev->watch_event);
+	if (ret < 0)
+		return ret;
+
+	rbd_assert(rbd_dev->watch_event);
 
-	ret = -ENOMEM;
 	obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
-							OBJ_REQUEST_NODATA);
-	if (!obj_request)
+					     OBJ_REQUEST_NODATA);
+	if (!obj_request) {
+		ret = -ENOMEM;
 		goto out_cancel;
+	}
 
 	obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, 1,
 						  obj_request);
-	if (!obj_request->osd_req)
-		goto out_cancel;
+	if (!obj_request->osd_req) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
 
-	if (start)
-		ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
-	else
-		ceph_osdc_unregister_linger_request(osdc,
-					rbd_dev->watch_request->osd_req);
+	ceph_osdc_set_request_linger(osdc, obj_request->osd_req);
 
 	osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
-				rbd_dev->watch_event->cookie, 0, start ? 1 : 0);
+			      rbd_dev->watch_event->cookie, 0, 1);
 	rbd_osd_req_format_write(obj_request);
 
 	ret = rbd_obj_request_submit(osdc, obj_request);
 	if (ret)
-		goto out_cancel;
+		goto out_linger;
+
 	ret = rbd_obj_request_wait(obj_request);
 	if (ret)
-		goto out_cancel;
+		goto out_linger;
+
 	ret = obj_request->result;
 	if (ret)
-		goto out_cancel;
+		goto out_linger;
 
 	/*
 	 * A watch request is set to linger, so the underlying osd
@@ -2931,36 +3004,84 @@ static int __rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start)
 	 * it.  We'll drop that reference (below) after we've
 	 * unregistered it.
 	 */
-	if (start) {
-		rbd_dev->watch_request = obj_request;
+	rbd_dev->watch_request = obj_request;
 
-		return 0;
+	return 0;
+
+out_linger:
+	ceph_osdc_unregister_linger_request(osdc, obj_request->osd_req);
+out_put:
+	rbd_obj_request_put(obj_request);
+out_cancel:
+	ceph_osdc_cancel_event(rbd_dev->watch_event);
+	rbd_dev->watch_event = NULL;
+
+	return ret;
+}
+
+/*
+ * Tear down a watch request, synchronously.
+ */
+static int __rbd_dev_header_unwatch_sync(struct rbd_device *rbd_dev)
+{
+	struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+	struct rbd_obj_request *obj_request;
+	int ret;
+
+	rbd_assert(rbd_dev->watch_event);
+	rbd_assert(rbd_dev->watch_request);
+
+	obj_request = rbd_obj_request_create(rbd_dev->header_name, 0, 0,
+					     OBJ_REQUEST_NODATA);
+	if (!obj_request) {
+		ret = -ENOMEM;
+		goto out_cancel;
+	}
+
+	obj_request->osd_req = rbd_osd_req_create(rbd_dev, true, 1,
+						  obj_request);
+	if (!obj_request->osd_req) {
+		ret = -ENOMEM;
+		goto out_put;
 	}
 
+	osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH,
+			      rbd_dev->watch_event->cookie, 0, 0);
+	rbd_osd_req_format_write(obj_request);
+
+	ret = rbd_obj_request_submit(osdc, obj_request);
+	if (ret)
+		goto out_put;
+
+	ret = rbd_obj_request_wait(obj_request);
+	if (ret)
+		goto out_put;
+
+	ret = obj_request->result;
+	if (ret)
+		goto out_put;
+
 	/* We have successfully torn down the watch request */
 
+	ceph_osdc_unregister_linger_request(osdc,
+					    rbd_dev->watch_request->osd_req);
 	rbd_obj_request_put(rbd_dev->watch_request);
 	rbd_dev->watch_request = NULL;
+
+out_put:
+	rbd_obj_request_put(obj_request);
 out_cancel:
-	/* Cancel the event if we're tearing down, or on error */
 	ceph_osdc_cancel_event(rbd_dev->watch_event);
 	rbd_dev->watch_event = NULL;
-	if (obj_request)
-		rbd_obj_request_put(obj_request);
 
 	return ret;
 }
 
-static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev)
-{
-	return __rbd_dev_header_watch_sync(rbd_dev, true);
-}
-
 static void rbd_dev_header_unwatch_sync(struct rbd_device *rbd_dev)
 {
 	int ret;
 
-	ret = __rbd_dev_header_watch_sync(rbd_dev, false);
+	ret = __rbd_dev_header_unwatch_sync(rbd_dev);
 	if (ret) {
 		rbd_warn(rbd_dev, "unable to tear down watch request: %d\n",
 			 ret);
@@ -3058,7 +3179,6 @@ static void rbd_request_fn(struct request_queue *q)
 		__releases(q->queue_lock) __acquires(q->queue_lock)
 {
 	struct rbd_device *rbd_dev = q->queuedata;
-	bool read_only = rbd_dev->mapping.read_only;
 	struct request *rq;
 	int result;
 
@@ -3094,7 +3214,7 @@ static void rbd_request_fn(struct request_queue *q)
 
 		if (write_request) {
 			result = -EROFS;
-			if (read_only)
+			if (rbd_dev->mapping.read_only)
 				goto end_request;
 			rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
 		}
@@ -4683,6 +4803,38 @@ out_err:
 }
 
 /*
+ * Return pool id (>= 0) or a negative error code.
+ */
+static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
+{
+	u64 newest_epoch;
+	unsigned long timeout = rbdc->client->options->mount_timeout * HZ;
+	int tries = 0;
+	int ret;
+
+again:
+	ret = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, pool_name);
+	if (ret == -ENOENT && tries++ < 1) {
+		ret = ceph_monc_do_get_version(&rbdc->client->monc, "osdmap",
+					       &newest_epoch);
+		if (ret < 0)
+			return ret;
+
+		if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
+			ceph_monc_request_next_osdmap(&rbdc->client->monc);
+			(void) ceph_monc_wait_osdmap(&rbdc->client->monc,
+						     newest_epoch, timeout);
+			goto again;
+		} else {
+			/* the osdmap we have is new enough */
+			return -ENOENT;
+		}
+	}
+
+	return ret;
+}
+
+/*
  * An rbd format 2 image has a unique identifier, distinct from the
  * name given to it by the user.  Internally, that identifier is
  * what's used to specify the names of objects related to the image.
@@ -4752,7 +4904,7 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
 
 		image_id = ceph_extract_encoded_string(&p, p + ret,
 						NULL, GFP_NOIO);
-		ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
+		ret = PTR_ERR_OR_ZERO(image_id);
 		if (!ret)
 			rbd_dev->image_format = 2;
 	} else {
@@ -4907,6 +5059,7 @@ static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
 	if (ret)
 		goto err_out_disk;
 	set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
+	set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
 
 	ret = rbd_bus_add_dev(rbd_dev);
 	if (ret)
@@ -5053,7 +5206,6 @@ static ssize_t do_rbd_add(struct bus_type *bus,
 	struct rbd_options *rbd_opts = NULL;
 	struct rbd_spec *spec = NULL;
 	struct rbd_client *rbdc;
-	struct ceph_osd_client *osdc;
 	bool read_only;
 	int rc = -ENOMEM;
 
@@ -5075,8 +5227,7 @@ static ssize_t do_rbd_add(struct bus_type *bus,
 	}
 
 	/* pick the pool */
-	osdc = &rbdc->client->osdc;
-	rc = ceph_pg_poolid_by_name(osdc->osdmap, spec->pool_name);
+	rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
 	if (rc < 0)
 		goto err_out_client;
 	spec->pool_id = (u64)rc;
@@ -5387,6 +5538,7 @@ err_out_slab:
 
 static void __exit rbd_exit(void)
 {
+	ida_destroy(&rbd_dev_id_ida);
 	rbd_sysfs_cleanup();
 	if (single_major)
 		unregister_blkdev(rbd_major, RBD_DRV_NAME);
diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index 21887d63dad5..469f2e8657e8 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -104,12 +104,6 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 	umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
 	struct dentry *dentry;
 
-	if (acl) {
-		ret = posix_acl_valid(acl);
-		if (ret < 0)
-			goto out;
-	}
-
 	switch (type) {
 	case ACL_TYPE_ACCESS:
 		name = POSIX_ACL_XATTR_ACCESS;
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 4f3f69079f36..90b3954d48ed 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -211,18 +211,15 @@ static int readpage_nounlock(struct file *filp, struct page *page)
 		SetPageError(page);
 		ceph_fscache_readpage_cancel(inode, page);
 		goto out;
-	} else {
-		if (err < PAGE_CACHE_SIZE) {
-		/* zero fill remainder of page */
-			zero_user_segment(page, err, PAGE_CACHE_SIZE);
-		} else {
-			flush_dcache_page(page);
-		}
 	}
-	SetPageUptodate(page);
+	if (err < PAGE_CACHE_SIZE)
+		/* zero fill remainder of page */
+		zero_user_segment(page, err, PAGE_CACHE_SIZE);
+	else
+		flush_dcache_page(page);
 
-	if (err >= 0)
-		ceph_readpage_to_fscache(inode, page);
+	SetPageUptodate(page);
+	ceph_readpage_to_fscache(inode, page);
 
 out:
 	return err < 0 ? err : 0;
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index c561b628ebce..1fde164b74b5 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -221,8 +221,8 @@ int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 	return 0;
 }
 
-static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
-				struct ceph_cap_reservation *ctx)
+struct ceph_cap *ceph_get_cap(struct ceph_mds_client *mdsc,
+			      struct ceph_cap_reservation *ctx)
 {
 	struct ceph_cap *cap = NULL;
 
@@ -508,15 +508,14 @@ static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
  * it is < 0.  (This is so we can atomically add the cap and add an
  * open file reference to it.)
  */
-int ceph_add_cap(struct inode *inode,
-		 struct ceph_mds_session *session, u64 cap_id,
-		 int fmode, unsigned issued, unsigned wanted,
-		 unsigned seq, unsigned mseq, u64 realmino, int flags,
-		 struct ceph_cap_reservation *caps_reservation)
+void ceph_add_cap(struct inode *inode,
+		  struct ceph_mds_session *session, u64 cap_id,
+		  int fmode, unsigned issued, unsigned wanted,
+		  unsigned seq, unsigned mseq, u64 realmino, int flags,
+		  struct ceph_cap **new_cap)
 {
 	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_cap *new_cap = NULL;
 	struct ceph_cap *cap;
 	int mds = session->s_mds;
 	int actual_wanted;
@@ -531,20 +530,10 @@ int ceph_add_cap(struct inode *inode,
 	if (fmode >= 0)
 		wanted |= ceph_caps_for_mode(fmode);
 
-retry:
-	spin_lock(&ci->i_ceph_lock);
 	cap = __get_cap_for_mds(ci, mds);
 	if (!cap) {
-		if (new_cap) {
-			cap = new_cap;
-			new_cap = NULL;
-		} else {
-			spin_unlock(&ci->i_ceph_lock);
-			new_cap = get_cap(mdsc, caps_reservation);
-			if (new_cap == NULL)
-				return -ENOMEM;
-			goto retry;
-		}
+		cap = *new_cap;
+		*new_cap = NULL;
 
 		cap->issued = 0;
 		cap->implemented = 0;
@@ -562,9 +551,6 @@ retry:
 		session->s_nr_caps++;
 		spin_unlock(&session->s_cap_lock);
 	} else {
-		if (new_cap)
-			ceph_put_cap(mdsc, new_cap);
-
 		/*
 		 * auth mds of the inode changed. we received the cap export
 		 * message, but still haven't received the cap import message.
@@ -626,7 +612,6 @@ retry:
 			ci->i_auth_cap = cap;
 			cap->mds_wanted = wanted;
 		}
-		ci->i_cap_exporting_issued = 0;
 	} else {
 		WARN_ON(ci->i_auth_cap == cap);
 	}
@@ -648,9 +633,6 @@ retry:
 
 	if (fmode >= 0)
 		__ceph_get_fmode(ci, fmode);
-	spin_unlock(&ci->i_ceph_lock);
-	wake_up_all(&ci->i_cap_wq);
-	return 0;
 }
 
 /*
@@ -685,7 +667,7 @@ static int __cap_is_valid(struct ceph_cap *cap)
  */
 int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
 {
-	int have = ci->i_snap_caps | ci->i_cap_exporting_issued;
+	int have = ci->i_snap_caps;
 	struct ceph_cap *cap;
 	struct rb_node *p;
 
@@ -900,7 +882,7 @@ int __ceph_caps_mds_wanted(struct ceph_inode_info *ci)
  */
 static int __ceph_is_any_caps(struct ceph_inode_info *ci)
 {
-	return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_issued;
+	return !RB_EMPTY_ROOT(&ci->i_caps);
 }
 
 int ceph_is_any_caps(struct inode *inode)
@@ -2397,32 +2379,30 @@ static void invalidate_aliases(struct inode *inode)
  * actually be a revocation if it specifies a smaller cap set.)
  *
  * caller holds s_mutex and i_ceph_lock, we drop both.
- *
- * return value:
- *  0 - ok
- *  1 - check_caps on auth cap only (writeback)
- *  2 - check_caps (ack revoke)
  */
-static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
+static void handle_cap_grant(struct ceph_mds_client *mdsc,
+			     struct inode *inode, struct ceph_mds_caps *grant,
+			     void *snaptrace, int snaptrace_len,
+			     struct ceph_buffer *xattr_buf,
 			     struct ceph_mds_session *session,
-			     struct ceph_cap *cap,
-			     struct ceph_buffer *xattr_buf)
-		__releases(ci->i_ceph_lock)
+			     struct ceph_cap *cap, int issued)
+	__releases(ci->i_ceph_lock)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	int mds = session->s_mds;
 	int seq = le32_to_cpu(grant->seq);
 	int newcaps = le32_to_cpu(grant->caps);
-	int issued, implemented, used, wanted, dirty;
+	int used, wanted, dirty;
 	u64 size = le64_to_cpu(grant->size);
 	u64 max_size = le64_to_cpu(grant->max_size);
 	struct timespec mtime, atime, ctime;
 	int check_caps = 0;
-	int wake = 0;
-	int writeback = 0;
-	int queue_invalidate = 0;
-	int deleted_inode = 0;
-	int queue_revalidate = 0;
+	bool wake = 0;
+	bool writeback = 0;
+	bool queue_trunc = 0;
+	bool queue_invalidate = 0;
+	bool queue_revalidate = 0;
+	bool deleted_inode = 0;
 
 	dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
 	     inode, cap, mds, seq, ceph_cap_string(newcaps));
@@ -2466,16 +2446,13 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 	}
 
 	/* side effects now are allowed */
-
-	issued = __ceph_caps_issued(ci, &implemented);
-	issued |= implemented | __ceph_caps_dirty(ci);
-
 	cap->cap_gen = session->s_cap_gen;
 	cap->seq = seq;
 
 	__check_cap_issue(ci, cap, newcaps);
 
-	if ((issued & CEPH_CAP_AUTH_EXCL) == 0) {
+	if ((newcaps & CEPH_CAP_AUTH_SHARED) &&
+	    (issued & CEPH_CAP_AUTH_EXCL) == 0) {
 		inode->i_mode = le32_to_cpu(grant->mode);
 		inode->i_uid = make_kuid(&init_user_ns, le32_to_cpu(grant->uid));
 		inode->i_gid = make_kgid(&init_user_ns, le32_to_cpu(grant->gid));
@@ -2484,7 +2461,8 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 		     from_kgid(&init_user_ns, inode->i_gid));
 	}
 
-	if ((issued & CEPH_CAP_LINK_EXCL) == 0) {
+	if ((newcaps & CEPH_CAP_AUTH_SHARED) &&
+	    (issued & CEPH_CAP_LINK_EXCL) == 0) {
 		set_nlink(inode, le32_to_cpu(grant->nlink));
 		if (inode->i_nlink == 0 &&
 		    (newcaps & (CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL)))
@@ -2511,30 +2489,35 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 	if ((issued & CEPH_CAP_FILE_CACHE) && ci->i_rdcache_gen > 1)
 		queue_revalidate = 1;
 
-	/* size/ctime/mtime/atime? */
-	ceph_fill_file_size(inode, issued,
-			    le32_to_cpu(grant->truncate_seq),
-			    le64_to_cpu(grant->truncate_size), size);
-	ceph_decode_timespec(&mtime, &grant->mtime);
-	ceph_decode_timespec(&atime, &grant->atime);
-	ceph_decode_timespec(&ctime, &grant->ctime);
-	ceph_fill_file_time(inode, issued,
-			    le32_to_cpu(grant->time_warp_seq), &ctime, &mtime,
-			    &atime);
-
-
-	/* file layout may have changed */
-	ci->i_layout = grant->layout;
-
-	/* max size increase? */
-	if (ci->i_auth_cap == cap && max_size != ci->i_max_size) {
-		dout("max_size %lld -> %llu\n", ci->i_max_size, max_size);
-		ci->i_max_size = max_size;
-		if (max_size >= ci->i_wanted_max_size) {
-			ci->i_wanted_max_size = 0;  /* reset */
-			ci->i_requested_max_size = 0;
+	if (newcaps & CEPH_CAP_ANY_RD) {
+		/* ctime/mtime/atime? */
+		ceph_decode_timespec(&mtime, &grant->mtime);
+		ceph_decode_timespec(&atime, &grant->atime);
+		ceph_decode_timespec(&ctime, &grant->ctime);
+		ceph_fill_file_time(inode, issued,
+				    le32_to_cpu(grant->time_warp_seq),
+				    &ctime, &mtime, &atime);
+	}
+
+	if (newcaps & (CEPH_CAP_ANY_FILE_RD | CEPH_CAP_ANY_FILE_WR)) {
+		/* file layout may have changed */
+		ci->i_layout = grant->layout;
+		/* size/truncate_seq? */
+		queue_trunc = ceph_fill_file_size(inode, issued,
+					le32_to_cpu(grant->truncate_seq),
+					le64_to_cpu(grant->truncate_size),
+					size);
+		/* max size increase? */
+		if (ci->i_auth_cap == cap && max_size != ci->i_max_size) {
+			dout("max_size %lld -> %llu\n",
+			     ci->i_max_size, max_size);
+			ci->i_max_size = max_size;
+			if (max_size >= ci->i_wanted_max_size) {
+				ci->i_wanted_max_size = 0;  /* reset */
+				ci->i_requested_max_size = 0;
+			}
+			wake = 1;
 		}
-		wake = 1;
 	}
 
 	/* check cap bits */
@@ -2595,6 +2578,23 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 
 	spin_unlock(&ci->i_ceph_lock);
 
+	if (le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT) {
+		down_write(&mdsc->snap_rwsem);
+		ceph_update_snap_trace(mdsc, snaptrace,
+				       snaptrace + snaptrace_len, false);
+		downgrade_write(&mdsc->snap_rwsem);
+		kick_flushing_inode_caps(mdsc, session, inode);
+		up_read(&mdsc->snap_rwsem);
+		if (newcaps & ~issued)
+			wake = 1;
+	}
+
+	if (queue_trunc) {
+		ceph_queue_vmtruncate(inode);
+		ceph_queue_revalidate(inode);
+	} else if (queue_revalidate)
+		ceph_queue_revalidate(inode);
+
 	if (writeback)
 		/*
 		 * queue inode for writeback: we can't actually call
@@ -2606,8 +2606,6 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 		ceph_queue_invalidate(inode);
 	if (deleted_inode)
 		invalidate_aliases(inode);
-	if (queue_revalidate)
-		ceph_queue_revalidate(inode);
 	if (wake)
 		wake_up_all(&ci->i_cap_wq);
 
@@ -2784,7 +2782,7 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 {
 	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 	struct ceph_mds_session *tsession = NULL;
-	struct ceph_cap *cap, *tcap;
+	struct ceph_cap *cap, *tcap, *new_cap = NULL;
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	u64 t_cap_id;
 	unsigned mseq = le32_to_cpu(ex->migrate_seq);
@@ -2807,7 +2805,7 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 retry:
 	spin_lock(&ci->i_ceph_lock);
 	cap = __get_cap_for_mds(ci, mds);
-	if (!cap)
+	if (!cap || cap->cap_id != le64_to_cpu(ex->cap_id))
 		goto out_unlock;
 
 	if (target < 0) {
@@ -2846,15 +2844,14 @@ retry:
 		}
 		__ceph_remove_cap(cap, false);
 		goto out_unlock;
-	}
-
-	if (tsession) {
-		int flag = (cap == ci->i_auth_cap) ? CEPH_CAP_FLAG_AUTH : 0;
-		spin_unlock(&ci->i_ceph_lock);
+	} else if (tsession) {
 		/* add placeholder for the export tagert */
+		int flag = (cap == ci->i_auth_cap) ? CEPH_CAP_FLAG_AUTH : 0;
 		ceph_add_cap(inode, tsession, t_cap_id, -1, issued, 0,
-			     t_seq - 1, t_mseq, (u64)-1, flag, NULL);
-		goto retry;
+			     t_seq - 1, t_mseq, (u64)-1, flag, &new_cap);
+
+		__ceph_remove_cap(cap, false);
+		goto out_unlock;
 	}
 
 	spin_unlock(&ci->i_ceph_lock);
@@ -2873,6 +2870,7 @@ retry:
 					  SINGLE_DEPTH_NESTING);
 		}
 		ceph_add_cap_releases(mdsc, tsession);
+		new_cap = ceph_get_cap(mdsc, NULL);
 	} else {
 		WARN_ON(1);
 		tsession = NULL;
@@ -2887,24 +2885,27 @@ out_unlock:
 		mutex_unlock(&tsession->s_mutex);
 		ceph_put_mds_session(tsession);
 	}
+	if (new_cap)
+		ceph_put_cap(mdsc, new_cap);
 }
 
 /*
- * Handle cap IMPORT.  If there are temp bits from an older EXPORT,
- * clean them up.
+ * Handle cap IMPORT.
  *
- * caller holds s_mutex.
+ * caller holds s_mutex. acquires i_ceph_lock
  */
 static void handle_cap_import(struct ceph_mds_client *mdsc,
 			      struct inode *inode, struct ceph_mds_caps *im,
 			      struct ceph_mds_cap_peer *ph,
 			      struct ceph_mds_session *session,
-			      void *snaptrace, int snaptrace_len)
+			      struct ceph_cap **target_cap, int *old_issued)
+	__acquires(ci->i_ceph_lock)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_cap *cap;
+	struct ceph_cap *cap, *ocap, *new_cap = NULL;
 	int mds = session->s_mds;
-	unsigned issued = le32_to_cpu(im->caps);
+	int issued;
+	unsigned caps = le32_to_cpu(im->caps);
 	unsigned wanted = le32_to_cpu(im->wanted);
 	unsigned seq = le32_to_cpu(im->seq);
 	unsigned mseq = le32_to_cpu(im->migrate_seq);
@@ -2924,40 +2925,52 @@ static void handle_cap_import(struct ceph_mds_client *mdsc,
 	dout("handle_cap_import inode %p ci %p mds%d mseq %d peer %d\n",
 	     inode, ci, mds, mseq, peer);
 
+retry:
 	spin_lock(&ci->i_ceph_lock);
-	cap = peer >= 0 ? __get_cap_for_mds(ci, peer) : NULL;
-	if (cap && cap->cap_id == p_cap_id) {
+	cap = __get_cap_for_mds(ci, mds);
+	if (!cap) {
+		if (!new_cap) {
+			spin_unlock(&ci->i_ceph_lock);
+			new_cap = ceph_get_cap(mdsc, NULL);
+			goto retry;
+		}
+		cap = new_cap;
+	} else {
+		if (new_cap) {
+			ceph_put_cap(mdsc, new_cap);
+			new_cap = NULL;
+		}
+	}
+
+	__ceph_caps_issued(ci, &issued);
+	issued |= __ceph_caps_dirty(ci);
+
+	ceph_add_cap(inode, session, cap_id, -1, caps, wanted, seq, mseq,
+		     realmino, CEPH_CAP_FLAG_AUTH, &new_cap);
+
+	ocap = peer >= 0 ? __get_cap_for_mds(ci, peer) : NULL;
+	if (ocap && ocap->cap_id == p_cap_id) {
 		dout(" remove export cap %p mds%d flags %d\n",
-		     cap, peer, ph->flags);
+		     ocap, peer, ph->flags);
 		if ((ph->flags & CEPH_CAP_FLAG_AUTH) &&
-		    (cap->seq != le32_to_cpu(ph->seq) ||
-		     cap->mseq != le32_to_cpu(ph->mseq))) {
+		    (ocap->seq != le32_to_cpu(ph->seq) ||
+		     ocap->mseq != le32_to_cpu(ph->mseq))) {
 			pr_err("handle_cap_import: mismatched seq/mseq: "
 			       "ino (%llx.%llx) mds%d seq %d mseq %d "
 			       "importer mds%d has peer seq %d mseq %d\n",
-			       ceph_vinop(inode), peer, cap->seq,
-			       cap->mseq, mds, le32_to_cpu(ph->seq),
+			       ceph_vinop(inode), peer, ocap->seq,
+			       ocap->mseq, mds, le32_to_cpu(ph->seq),
 			       le32_to_cpu(ph->mseq));
 		}
-		ci->i_cap_exporting_issued = cap->issued;
-		__ceph_remove_cap(cap, (ph->flags & CEPH_CAP_FLAG_RELEASE));
+		__ceph_remove_cap(ocap, (ph->flags & CEPH_CAP_FLAG_RELEASE));
 	}
 
 	/* make sure we re-request max_size, if necessary */
 	ci->i_wanted_max_size = 0;
 	ci->i_requested_max_size = 0;
-	spin_unlock(&ci->i_ceph_lock);
-
-	down_write(&mdsc->snap_rwsem);
-	ceph_update_snap_trace(mdsc, snaptrace, snaptrace+snaptrace_len,
-			       false);
-	downgrade_write(&mdsc->snap_rwsem);
-	ceph_add_cap(inode, session, cap_id, -1,
-		     issued, wanted, seq, mseq, realmino, CEPH_CAP_FLAG_AUTH,
-		     NULL /* no caps context */);
-	kick_flushing_inode_caps(mdsc, session, inode);
-	up_read(&mdsc->snap_rwsem);
 
+	*old_issued = issued;
+	*target_cap = cap;
 }
 
 /*
@@ -2977,7 +2990,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 	struct ceph_mds_caps *h;
 	struct ceph_mds_cap_peer *peer = NULL;
 	int mds = session->s_mds;
-	int op;
+	int op, issued;
 	u32 seq, mseq;
 	struct ceph_vino vino;
 	u64 cap_id;
@@ -3069,7 +3082,10 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 
 	case CEPH_CAP_OP_IMPORT:
 		handle_cap_import(mdsc, inode, h, peer, session,
-				  snaptrace, snaptrace_len);
+				  &cap, &issued);
+		handle_cap_grant(mdsc, inode, h,  snaptrace, snaptrace_len,
+				 msg->middle, session, cap, issued);
+		goto done_unlocked;
 	}
 
 	/* the rest require a cap */
@@ -3086,8 +3102,10 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 	switch (op) {
 	case CEPH_CAP_OP_REVOKE:
 	case CEPH_CAP_OP_GRANT:
-	case CEPH_CAP_OP_IMPORT:
-		handle_cap_grant(inode, h, session, cap, msg->middle);
+		__ceph_caps_issued(ci, &issued);
+		issued |= __ceph_caps_dirty(ci);
+		handle_cap_grant(mdsc, inode, h, NULL, 0, msg->middle,
+				 session, cap, issued);
 		goto done_unlocked;
 
 	case CEPH_CAP_OP_FLUSH_ACK:
diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index 00d6af6a32ec..8d7d782f4382 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -169,7 +169,7 @@ static struct dentry *__get_parent(struct super_block *sb,
 	return dentry;
 }
 
-struct dentry *ceph_get_parent(struct dentry *child)
+static struct dentry *ceph_get_parent(struct dentry *child)
 {
 	/* don't re-export snaps */
 	if (ceph_snap(child->d_inode) != CEPH_NOSNAP)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index e4fff9ff1c27..04c89c266cec 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -10,6 +10,7 @@
 #include <linux/writeback.h>
 #include <linux/vmalloc.h>
 #include <linux/posix_acl.h>
+#include <linux/random.h>
 
 #include "super.h"
 #include "mds_client.h"
@@ -179,9 +180,8 @@ struct ceph_inode_frag *__ceph_find_frag(struct ceph_inode_info *ci, u32 f)
  * specified, copy the frag delegation info to the caller if
  * it is present.
  */
-u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
-		     struct ceph_inode_frag *pfrag,
-		     int *found)
+static u32 __ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
+			      struct ceph_inode_frag *pfrag, int *found)
 {
 	u32 t = ceph_frag_make(0, 0);
 	struct ceph_inode_frag *frag;
@@ -191,7 +191,6 @@ u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
 	if (found)
 		*found = 0;
 
-	mutex_lock(&ci->i_fragtree_mutex);
 	while (1) {
 		WARN_ON(!ceph_frag_contains_value(t, v));
 		frag = __ceph_find_frag(ci, t);
@@ -220,10 +219,19 @@ u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
 	}
 	dout("choose_frag(%x) = %x\n", v, t);
 
-	mutex_unlock(&ci->i_fragtree_mutex);
 	return t;
 }
 
+u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
+		     struct ceph_inode_frag *pfrag, int *found)
+{
+	u32 ret;
+	mutex_lock(&ci->i_fragtree_mutex);
+	ret = __ceph_choose_frag(ci, v, pfrag, found);
+	mutex_unlock(&ci->i_fragtree_mutex);
+	return ret;
+}
+
 /*
  * Process dirfrag (delegation) info from the mds.  Include leaf
  * fragment in tree ONLY if ndist > 0.  Otherwise, only
@@ -237,11 +245,17 @@ static int ceph_fill_dirfrag(struct inode *inode,
 	u32 id = le32_to_cpu(dirinfo->frag);
 	int mds = le32_to_cpu(dirinfo->aut