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: (39 commits)
  ceph: generalize mon requests, add pool op support
  ceph: only queue async writeback on cap revocation if there is dirty data
  ceph: do not ignore osd_idle_ttl mount option
  ceph: constify dentry_operations
  ceph: whitespace cleanup
  ceph: add flock/fcntl lock support
  ceph: define on-wire types, constants for file locking support
  ceph: add CEPH_FEATURE_FLOCK to the supported feature bits
  ceph: support v2 reconnect encoding
  ceph: support v2 client_caps encoding
  ceph: move AES iv definition to shared header
  ceph: fix decoding of pool snap info
  ceph: make ->sync_fs not wait if wait==0
  ceph: warn on missing snap realm
  ceph: print useful error message when crush rule not found
  ceph: use %pU to print uuid (fsid)
  ceph: sync header defs with server code
  ceph: clean up header guards
  ceph: strip misleading/obsolete version, feature info
  ceph: specify supported features in super.h
  ...

39 files changed, 1162 insertions, 410 deletions

diff --git a/fs/ceph/Makefile b/fs/ceph/Makefile
index 6a660e610be..278e1172600 100644
--- a/fs/ceph/Makefile
+++ b/fs/ceph/Makefile
@@ -6,7 +6,7 @@ ifneq ($(KERNELRELEASE),)
 
 obj-$(CONFIG_CEPH_FS) += ceph.o
 
-ceph-objs := super.o inode.o dir.o file.o addr.o ioctl.o \
+ceph-objs := super.o inode.o dir.o file.o locks.o addr.o ioctl.o \
 	export.o caps.o snap.o xattr.o \
 	messenger.o msgpool.o buffer.o pagelist.o \
 	mds_client.o mdsmap.o \
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index d9c60b84949..5598a0d0229 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -309,7 +309,8 @@ static int ceph_readpages(struct file *file, struct address_space *mapping,
 			zero_user_segment(page, s, PAGE_CACHE_SIZE);
 		}
 
-		if (add_to_page_cache_lru(page, mapping, page->index, GFP_NOFS)) {
+		if (add_to_page_cache_lru(page, mapping, page->index,
+					  GFP_NOFS)) {
 			page_cache_release(page);
 			dout("readpages %p add_to_page_cache failed %p\n",
 			     inode, page);
@@ -552,7 +553,7 @@ static void writepages_finish(struct ceph_osd_request *req,
 		 * page truncation thread, possibly losing some data that
 		 * raced its way in
 		 */
-		if ((issued & CEPH_CAP_FILE_CACHE) == 0)
+		if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
 			generic_error_remove_page(inode->i_mapping, page);
 
 		unlock_page(page);
@@ -797,9 +798,12 @@ get_more_pages:
 			dout("%p will write page %p idx %lu\n",
 			     inode, page, page->index);
 
-			writeback_stat = atomic_long_inc_return(&client->writeback_count);
-			if (writeback_stat > CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) {
-				set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
+			writeback_stat =
+			       atomic_long_inc_return(&client->writeback_count);
+			if (writeback_stat > CONGESTION_ON_THRESH(
+				    client->mount_args->congestion_kb)) {
+				set_bdi_congested(&client->backing_dev_info,
+						  BLK_RW_ASYNC);
 			}
 
 			set_page_writeback(page);
@@ -1036,7 +1040,7 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
 		*pagep = page;
 
 		dout("write_begin file %p inode %p page %p %d~%d\n", file,
-	     	inode, page, (int)pos, (int)len);
+		     inode, page, (int)pos, (int)len);
 
 		r = ceph_update_writeable_page(file, pos, len, page);
 	} while (r == -EAGAIN);
diff --git a/fs/ceph/armor.c b/fs/ceph/armor.c
index 67b2c030924..eb2a666b0be 100644
--- a/fs/ceph/armor.c
+++ b/fs/ceph/armor.c
@@ -1,11 +1,15 @@
 
 #include <linux/errno.h>
 
+int ceph_armor(char *dst, const char *src, const char *end);
+int ceph_unarmor(char *dst, const char *src, const char *end);
+
 /*
  * base64 encode/decode.
  */
 
-const char *pem_key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+static const char *pem_key =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
 static int encode_bits(int c)
 {
diff --git a/fs/ceph/auth.c b/fs/ceph/auth.c
index 89490beaf53..6d2e3060062 100644
--- a/fs/ceph/auth.c
+++ b/fs/ceph/auth.c
@@ -20,7 +20,7 @@ static u32 supported_protocols[] = {
 	CEPH_AUTH_CEPHX
 };
 
-int ceph_auth_init_protocol(struct ceph_auth_client *ac, int protocol)
+static int ceph_auth_init_protocol(struct ceph_auth_client *ac, int protocol)
 {
 	switch (protocol) {
 	case CEPH_AUTH_NONE:
@@ -133,8 +133,8 @@ bad:
 	return -ERANGE;
 }
 
-int ceph_build_auth_request(struct ceph_auth_client *ac,
-			   void *msg_buf, size_t msg_len)
+static int ceph_build_auth_request(struct ceph_auth_client *ac,
+				   void *msg_buf, size_t msg_len)
 {
 	struct ceph_mon_request_header *monhdr = msg_buf;
 	void *p = monhdr + 1;
diff --git a/fs/ceph/auth_x.c b/fs/ceph/auth_x.c
index 6d44053ecff..582e0b2caf8 100644
--- a/fs/ceph/auth_x.c
+++ b/fs/ceph/auth_x.c
@@ -87,8 +87,8 @@ static int ceph_x_decrypt(struct ceph_crypto_key *secret,
 /*
  * get existing (or insert new) ticket handler
  */
-struct ceph_x_ticket_handler *get_ticket_handler(struct ceph_auth_client *ac,
-						 int service)
+static struct ceph_x_ticket_handler *
+get_ticket_handler(struct ceph_auth_client *ac, int service)
 {
 	struct ceph_x_ticket_handler *th;
 	struct ceph_x_info *xi = ac->private;
@@ -429,7 +429,7 @@ static int ceph_x_build_request(struct ceph_auth_client *ac,
 		auth->struct_v = 1;
 		auth->key = 0;
 		for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
-			auth->key ^= *u;
+			auth->key ^= *(__le64 *)u;
 		dout(" server_challenge %llx client_challenge %llx key %llx\n",
 		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
 		     le64_to_cpu(auth->key));
diff --git a/fs/ceph/buffer.c b/fs/ceph/buffer.c
index c67535d70aa..cd39f17021d 100644
--- a/fs/ceph/buffer.c
+++ b/fs/ceph/buffer.c
@@ -47,22 +47,6 @@ void ceph_buffer_release(struct kref *kref)
 	kfree(b);
 }
 
-int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp)
-{
-	b->vec.iov_base = kmalloc(len, gfp | __GFP_NOWARN);
-	if (b->vec.iov_base) {
-		b->is_vmalloc = false;
-	} else {
-		b->vec.iov_base = __vmalloc(len, gfp, PAGE_KERNEL);
-		b->is_vmalloc = true;
-	}
-	if (!b->vec.iov_base)
-		return -ENOMEM;
-	b->alloc_len = len;
-	b->vec.iov_len = len;
-	return 0;
-}
-
 int ceph_decode_buffer(struct ceph_buffer **b, void **p, void *end)
 {
 	size_t len;
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index b81be9a5648..7bf182b0397 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -113,58 +113,41 @@ const char *ceph_cap_string(int caps)
 	return cap_str[i];
 }
 
-/*
- * Cap reservations
- *
- * Maintain a global pool of preallocated struct ceph_caps, referenced
- * by struct ceph_caps_reservations.  This ensures that we preallocate
- * memory needed to successfully process an MDS response.  (If an MDS
- * sends us cap information and we fail to process it, we will have
- * problems due to the client and MDS being out of sync.)
- *
- * Reservations are 'owned' by a ceph_cap_reservation context.
- */
-static spinlock_t caps_list_lock;
-static struct list_head caps_list;  /* unused (reserved or unreserved) */
-static int caps_total_count;        /* total caps allocated */
-static int caps_use_count;          /* in use */
-static int caps_reserve_count;      /* unused, reserved */
-static int caps_avail_count;        /* unused, unreserved */
-static int caps_min_count;          /* keep at least this many (unreserved) */
-
-void __init ceph_caps_init(void)
+void ceph_caps_init(struct ceph_mds_client *mdsc)
 {
-	INIT_LIST_HEAD(&caps_list);
-	spin_lock_init(&caps_list_lock);
+	INIT_LIST_HEAD(&mdsc->caps_list);
+	spin_lock_init(&mdsc->caps_list_lock);
 }
 
-void ceph_caps_finalize(void)
+void ceph_caps_finalize(struct ceph_mds_client *mdsc)
 {
 	struct ceph_cap *cap;
 
-	spin_lock(&caps_list_lock);
-	while (!list_empty(&caps_list)) {
-		cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
+	spin_lock(&mdsc->caps_list_lock);
+	while (!list_empty(&mdsc->caps_list)) {
+		cap = list_first_entry(&mdsc->caps_list,
+				       struct ceph_cap, caps_item);
 		list_del(&cap->caps_item);
 		kmem_cache_free(ceph_cap_cachep, cap);
 	}
-	caps_total_count = 0;
-	caps_avail_count = 0;
-	caps_use_count = 0;
-	caps_reserve_count = 0;
-	caps_min_count = 0;
-	spin_unlock(&caps_list_lock);
+	mdsc->caps_total_count = 0;
+	mdsc->caps_avail_count = 0;
+	mdsc->caps_use_count = 0;
+	mdsc->caps_reserve_count = 0;
+	mdsc->caps_min_count = 0;
+	spin_unlock(&mdsc->caps_list_lock);
 }
 
-void ceph_adjust_min_caps(int delta)
+void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta)
 {
-	spin_lock(&caps_list_lock);
-	caps_min_count += delta;
-	BUG_ON(caps_min_count < 0);
-	spin_unlock(&caps_list_lock);
+	spin_lock(&mdsc->caps_list_lock);
+	mdsc->caps_min_count += delta;
+	BUG_ON(mdsc->caps_min_count < 0);
+	spin_unlock(&mdsc->caps_list_lock);
 }
 
-int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
+int ceph_reserve_caps(struct ceph_mds_client *mdsc,
+		      struct ceph_cap_reservation *ctx, int need)
 {
 	int i;
 	struct ceph_cap *cap;
@@ -176,16 +159,17 @@ int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
 	dout("reserve caps ctx=%p need=%d\n", ctx, need);
 
 	/* first reserve any caps that are already allocated */
-	spin_lock(&caps_list_lock);
-	if (caps_avail_count >= need)
+	spin_lock(&mdsc->caps_list_lock);
+	if (mdsc->caps_avail_count >= need)
 		have = need;
 	else
-		have = caps_avail_count;
-	caps_avail_count -= have;
-	caps_reserve_count += have;
-	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-	       caps_avail_count);
-	spin_unlock(&caps_list_lock);
+		have = mdsc->caps_avail_count;
+	mdsc->caps_avail_count -= have;
+	mdsc->caps_reserve_count += have;
+	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+					 mdsc->caps_reserve_count +
+					 mdsc->caps_avail_count);
+	spin_unlock(&mdsc->caps_list_lock);
 
 	for (i = have; i < need; i++) {
 		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
@@ -198,19 +182,20 @@ int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
 	}
 	BUG_ON(have + alloc != need);
 
-	spin_lock(&caps_list_lock);
-	caps_total_count += alloc;
-	caps_reserve_count += alloc;
-	list_splice(&newcaps, &caps_list);
+	spin_lock(&mdsc->caps_list_lock);
+	mdsc->caps_total_count += alloc;
+	mdsc->caps_reserve_count += alloc;
+	list_splice(&newcaps, &mdsc->caps_list);
 
-	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-	       caps_avail_count);
-	spin_unlock(&caps_list_lock);
+	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+					 mdsc->caps_reserve_count +
+					 mdsc->caps_avail_count);
+	spin_unlock(&mdsc->caps_list_lock);
 
 	ctx->count = need;
 	dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
-	     ctx, caps_total_count, caps_use_count, caps_reserve_count,
-	     caps_avail_count);
+	     ctx, mdsc->caps_total_count, mdsc->caps_use_count,
+	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 	return 0;
 
 out_alloc_count:
@@ -220,26 +205,29 @@ out_alloc_count:
 	return ret;
 }
 
-int ceph_unreserve_caps(struct ceph_cap_reservation *ctx)
+int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
+			struct ceph_cap_reservation *ctx)
 {
 	dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
 	if (ctx->count) {
-		spin_lock(&caps_list_lock);
-		BUG_ON(caps_reserve_count < ctx->count);
-		caps_reserve_count -= ctx->count;
-		caps_avail_count += ctx->count;
+		spin_lock(&mdsc->caps_list_lock);
+		BUG_ON(mdsc->caps_reserve_count < ctx->count);
+		mdsc->caps_reserve_count -= ctx->count;
+		mdsc->caps_avail_count += ctx->count;
 		ctx->count = 0;
 		dout("unreserve caps %d = %d used + %d resv + %d avail\n",
-		     caps_total_count, caps_use_count, caps_reserve_count,
-		     caps_avail_count);
-		BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-		       caps_avail_count);
-		spin_unlock(&caps_list_lock);
+		     mdsc->caps_total_count, mdsc->caps_use_count,
+		     mdsc->caps_reserve_count, mdsc->caps_avail_count);
+		BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+						 mdsc->caps_reserve_count +
+						 mdsc->caps_avail_count);
+		spin_unlock(&mdsc->caps_list_lock);
 	}
 	return 0;
 }
 
-static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx)
+static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
+				struct ceph_cap_reservation *ctx)
 {
 	struct ceph_cap *cap = NULL;
 
@@ -247,71 +235,74 @@ static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx)
 	if (!ctx) {
 		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 		if (cap) {
-			caps_use_count++;
-			caps_total_count++;
+			mdsc->caps_use_count++;
+			mdsc->caps_total_count++;
 		}
 		return cap;
 	}
 
-	spin_lock(&caps_list_lock);
+	spin_lock(&mdsc->caps_list_lock);
 	dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
-	     ctx, ctx->count, caps_total_count, caps_use_count,
-	     caps_reserve_count, caps_avail_count);
+	     ctx, ctx->count, mdsc->caps_total_count, mdsc->caps_use_count,
+	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 	BUG_ON(!ctx->count);
-	BUG_ON(ctx->count > caps_reserve_count);
-	BUG_ON(list_empty(&caps_list));
+	BUG_ON(ctx->count > mdsc->caps_reserve_count);
+	BUG_ON(list_empty(&mdsc->caps_list));
 
 	ctx->count--;
-	caps_reserve_count--;
-	caps_use_count++;
+	mdsc->caps_reserve_count--;
+	mdsc->caps_use_count++;
 
-	cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
+	cap = list_first_entry(&mdsc->caps_list, struct ceph_cap, caps_item);
 	list_del(&cap->caps_item);
 
-	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-	       caps_avail_count);
-	spin_unlock(&caps_list_lock);
+	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
+	spin_unlock(&mdsc->caps_list_lock);
 	return cap;
 }
 
-void ceph_put_cap(struct ceph_cap *cap)
+void ceph_put_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap)
 {
-	spin_lock(&caps_list_lock);
+	spin_lock(&mdsc->caps_list_lock);
 	dout("put_cap %p %d = %d used + %d resv + %d avail\n",
-	     cap, caps_total_count, caps_use_count,
-	     caps_reserve_count, caps_avail_count);
-	caps_use_count--;
+	     cap, mdsc->caps_total_count, mdsc->caps_use_count,
+	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
+	mdsc->caps_use_count--;
 	/*
 	 * Keep some preallocated caps around (ceph_min_count), to
 	 * avoid lots of free/alloc churn.
 	 */
-	if (caps_avail_count >= caps_reserve_count + caps_min_count) {
-		caps_total_count--;
+	if (mdsc->caps_avail_count >= mdsc->caps_reserve_count +
+				      mdsc->caps_min_count) {
+		mdsc->caps_total_count--;
 		kmem_cache_free(ceph_cap_cachep, cap);
 	} else {
-		caps_avail_count++;
-		list_add(&cap->caps_item, &caps_list);
+		mdsc->caps_avail_count++;
+		list_add(&cap->caps_item, &mdsc->caps_list);
 	}
 
-	BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-	       caps_avail_count);
-	spin_unlock(&caps_list_lock);
+	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
+	spin_unlock(&mdsc->caps_list_lock);
 }
 
 void ceph_reservation_status(struct ceph_client *client,
 			     int *total, int *avail, int *used, int *reserved,
 			     int *min)
 {
+	struct ceph_mds_client *mdsc = &client->mdsc;
+
 	if (total)
-		*total = caps_total_count;
+		*total = mdsc->caps_total_count;
 	if (avail)
-		*avail = caps_avail_count;
+		*avail = mdsc->caps_avail_count;
 	if (used)
-		*used = caps_use_count;
+		*used = mdsc->caps_use_count;
 	if (reserved)
-		*reserved = caps_reserve_count;
+		*reserved = mdsc->caps_reserve_count;
 	if (min)
-		*min = caps_min_count;
+		*min = mdsc->caps_min_count;
 }
 
 /*
@@ -336,22 +327,29 @@ static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 	return NULL;
 }
 
+struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci, int mds)
+{
+	struct ceph_cap *cap;
+
+	spin_lock(&ci->vfs_inode.i_lock);
+	cap = __get_cap_for_mds(ci, mds);
+	spin_unlock(&ci->vfs_inode.i_lock);
+	return cap;
+}
+
 /*
- * Return id of any MDS with a cap, preferably FILE_WR|WRBUFFER|EXCL, else
- * -1.
+ * Return id of any MDS with a cap, preferably FILE_WR|BUFFER|EXCL, else -1.
  */
-static int __ceph_get_cap_mds(struct ceph_inode_info *ci, u32 *mseq)
+static int __ceph_get_cap_mds(struct ceph_inode_info *ci)
 {
 	struct ceph_cap *cap;
 	int mds = -1;
 	struct rb_node *p;
 
-	/* prefer mds with WR|WRBUFFER|EXCL caps */
+	/* prefer mds with WR|BUFFER|EXCL caps */
 	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 		cap = rb_entry(p, struct ceph_cap, ci_node);
 		mds = cap->mds;
-		if (mseq)
-			*mseq = cap->mseq;
 		if (cap->issued & (CEPH_CAP_FILE_WR |
 				   CEPH_CAP_FILE_BUFFER |
 				   CEPH_CAP_FILE_EXCL))
@@ -364,7 +362,7 @@ int ceph_get_cap_mds(struct inode *inode)
 {
 	int mds;
 	spin_lock(&inode->i_lock);
-	mds = __ceph_get_cap_mds(ceph_inode(inode), NULL);
+	mds = __ceph_get_cap_mds(ceph_inode(inode));
 	spin_unlock(&inode->i_lock);
 	return mds;
 }
@@ -483,8 +481,8 @@ static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
 	 * Each time we receive FILE_CACHE anew, we increment
 	 * i_rdcache_gen.
 	 */
-	if ((issued & CEPH_CAP_FILE_CACHE) &&
-	    (had & CEPH_CAP_FILE_CACHE) == 0)
+	if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
+	    (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
 		ci->i_rdcache_gen++;
 
 	/*
@@ -543,7 +541,7 @@ retry:
 			new_cap = NULL;
 		} else {
 			spin_unlock(&inode->i_lock);
-			new_cap = get_cap(caps_reservation);
+			new_cap = get_cap(mdsc, caps_reservation);
 			if (new_cap == NULL)
 				return -ENOMEM;
 			goto retry;
@@ -588,6 +586,7 @@ retry:
 		} else {
 			pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
 			       realmino);
+			WARN_ON(!realm);
 		}
 	}
 
@@ -831,7 +830,7 @@ int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
 {
 	int want = 0;
 	int mode;
-	for (mode = 0; mode < 4; mode++)
+	for (mode = 0; mode < CEPH_FILE_MODE_NUM; mode++)
 		if (ci->i_nr_by_mode[mode])
 			want |= ceph_caps_for_mode(mode);
 	return want;
@@ -901,7 +900,7 @@ void __ceph_remove_cap(struct ceph_cap *cap)
 		ci->i_auth_cap = NULL;
 
 	if (removed)
-		ceph_put_cap(cap);
+		ceph_put_cap(mdsc, cap);
 
 	if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
 		struct ceph_snap_realm *realm = ci->i_snap_realm;
@@ -1197,6 +1196,8 @@ static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
  */
 void __ceph_flush_snaps(struct ceph_inode_info *ci,
 			struct ceph_mds_session **psession)
+		__releases(ci->vfs_inode->i_lock)
+		__acquires(ci->vfs_inode->i_lock)
 {
 	struct inode *inode = &ci->vfs_inode;
 	int mds;
@@ -1232,7 +1233,13 @@ retry:
 		BUG_ON(capsnap->dirty == 0);
 
 		/* pick mds, take s_mutex */
-		mds = __ceph_get_cap_mds(ci, &mseq);
+		if (ci->i_auth_cap == NULL) {
+			dout("no auth cap (migrating?), doing nothing\n");
+			goto out;
+		}
+		mds = ci->i_auth_cap->session->s_mds;
+		mseq = ci->i_auth_cap->mseq;
+
 		if (session && session->s_mds != mds) {
 			dout("oops, wrong session %p mutex\n", session);
 			mutex_unlock(&session->s_mutex);
@@ -1251,8 +1258,8 @@ retry:
 			}
 			/*
 			 * if session == NULL, we raced against a cap
-			 * deletion.  retry, and we'll get a better
-			 * @mds value next time.
+			 * deletion or migration.  retry, and we'll
+			 * get a better @mds value next time.
 			 */
 			spin_lock(&inode->i_lock);
 			goto retry;
@@ -1290,6 +1297,7 @@ retry:
 	list_del_init(&ci->i_snap_flush_item);
 	spin_unlock(&mdsc->snap_flush_lock);
 
+out:
 	if (psession)
 		*psession = session;
 	else if (session) {
@@ -1435,7 +1443,6 @@ 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;
@@ -1510,11 +1517,13 @@ retry_locked:
 	    ci->i_wrbuffer_ref == 0 &&               /* no dirty pages... */
 	    ci->i_rdcache_gen &&                     /* may have cached pages */
 	    (file_wanted == 0 ||                     /* no open files */
-	     (revoking & CEPH_CAP_FILE_CACHE)) &&     /*  or revoking cache */
+	     (revoking & (CEPH_CAP_FILE_CACHE|
+			  CEPH_CAP_FILE_LAZYIO))) && /*  or revoking cache */
 	    !tried_invalidate) {
 		dout("check_caps trying to invalidate on %p\n", inode);
 		if (try_nonblocking_invalidate(inode) < 0) {
-			if (revoking & CEPH_CAP_FILE_CACHE) {
+			if (revoking & (CEPH_CAP_FILE_CACHE|
+					CEPH_CAP_FILE_LAZYIO)) {
 				dout("check_caps queuing invalidate\n");
 				queue_invalidate = 1;
 				ci->i_rdcache_revoking = ci->i_rdcache_gen;
@@ -2250,8 +2259,7 @@ 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)
+		__releases(inode->i_lock)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	int mds = session->s_mds;
@@ -2278,6 +2286,7 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 	 * will invalidate _after_ writeback.)
 	 */
 	if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
+	    (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
 	    !ci->i_wrbuffer_ref) {
 		if (try_nonblocking_invalidate(inode) == 0) {
 			revoked_rdcache = 1;
@@ -2369,15 +2378,22 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 
 	/* revocation, grant, or no-op? */
 	if (cap->issued & ~newcaps) {
-		dout("revocation: %s -> %s\n", ceph_cap_string(cap->issued),
-		     ceph_cap_string(newcaps));
-		if ((used & ~newcaps) & CEPH_CAP_FILE_BUFFER)
-			writeback = 1; /* will delay ack */
-		else if (dirty & ~newcaps)
-			check_caps = 1;  /* initiate writeback in check_caps */
-		else if (((used & ~newcaps) & CEPH_CAP_FILE_CACHE) == 0 ||
-			   revoked_rdcache)
-			check_caps = 2;     /* send revoke ack in check_caps */
+		int revoking = cap->issued & ~newcaps;
+
+		dout("revocation: %s -> %s (revoking %s)\n",
+		     ceph_cap_string(cap->issued),
+		     ceph_cap_string(newcaps),
+		     ceph_cap_string(revoking));
+		if (revoking & used & CEPH_CAP_FILE_BUFFER)
+			writeback = 1;  /* initiate writeback; will delay ack */
+		else if (revoking == CEPH_CAP_FILE_CACHE &&
+			 (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
+			 queue_invalidate)
+			; /* do nothing yet, invalidation will be queued */
+		else if (cap == ci->i_auth_cap)
+			check_caps = 1; /* check auth cap only */
+		else
+			check_caps = 2; /* check all caps */
 		cap->issued = newcaps;
 		cap->implemented |= newcaps;
 	} else if (cap->issued == newcaps) {
@@ -2568,7 +2584,8 @@ static void handle_cap_trunc(struct inode *inode,
  * caller holds s_mutex
  */
 static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
-			      struct ceph_mds_session *session)
+			      struct ceph_mds_session *session,
+			      int *open_target_sessions)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	int mds = session->s_mds;
@@ -2600,6 +2617,12 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
 			ci->i_cap_exporting_mds = mds;
 			ci->i_cap_exporting_mseq = mseq;
 			ci->i_cap_exporting_issued = cap->issued;
+
+			/*
+			 * make sure we have open sessions with all possible
+			 * export targets, so that we get the matching IMPORT
+			 */
+			*open_target_sessions = 1;
 		}
 		__ceph_remove_cap(cap);
 	}
@@ -2675,6 +2698,10 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 	u64 size, max_size;
 	u64 tid;
 	void *snaptrace;
+	size_t snaptrace_len;
+	void *flock;
+	u32 flock_len;
+	int open_target_sessions = 0;
 
 	dout("handle_caps from mds%d\n", mds);
 
@@ -2683,7 +2710,6 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 	if (msg->front.iov_len < sizeof(*h))
 		goto bad;
 	h = msg->front.iov_base;
-	snaptrace = h + 1;
 	op = le32_to_cpu(h->op);
 	vino.ino = le64_to_cpu(h->ino);
 	vino.snap = CEPH_NOSNAP;
@@ -2693,6 +2719,21 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 	size = le64_to_cpu(h->size);
 	max_size = le64_to_cpu(h->max_size);
 
+	snaptrace = h + 1;
+	snaptrace_len = le32_to_cpu(h->snap_trace_len);
+
+	if (le16_to_cpu(msg->hdr.version) >= 2) {
+		void *p, *end;
+
+		p = snaptrace + snaptrace_len;
+		end = msg->front.iov_base + msg->front.iov_len;
+		ceph_decode_32_safe(&p, end, flock_len, bad);
+		flock = p;
+	} else {
+		flock = NULL;
+		flock_len = 0;
+	}
+
 	mutex_lock(&session->s_mutex);
 	session->s_seq++;
 	dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
@@ -2714,7 +2755,7 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 		 * along for the mds (who clearly thinks we still have this
 		 * cap).
 		 */
-		ceph_add_cap_releases(mdsc, session, -1);
+		ceph_add_cap_releases(mdsc, session);
 		ceph_send_cap_releases(mdsc, session);
 		goto done;
 	}
@@ -2726,12 +2767,12 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 		goto done;
 
 	case CEPH_CAP_OP_EXPORT:
-		handle_cap_export(inode, h, session);
+		handle_cap_export(inode, h, session, &open_target_sessions);
 		goto done;
 
 	case CEPH_CAP_OP_IMPORT:
 		handle_cap_import(mdsc, inode, h, session,
-				  snaptrace, le32_to_cpu(h->snap_trace_