ceph: pre-allocate ceph_cap struct for ceph_add_cap()

So that ceph_add_cap() can be used while i_ceph_lock is locked.
This simplifies the code that handle cap import/export.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

1 files changed, 39 insertions, 31 deletions

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index f9e7399877d6..8ad50a30808e 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -341,7 +341,6 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	INIT_LIST_HEAD(&ci->i_cap_snaps);
 	ci->i_head_snapc = NULL;
 	ci->i_snap_caps = 0;
-	ci->i_cap_exporting_issued = 0;
 
 	for (i = 0; i < CEPH_FILE_MODE_NUM; i++)
 		ci->i_nr_by_mode[i] = 0;
@@ -407,7 +406,7 @@ void ceph_destroy_inode(struct inode *inode)
 
 	/*
 	 * we may still have a snap_realm reference if there are stray
-	 * caps in i_cap_exporting_issued or i_snap_caps.
+	 * caps in i_snap_caps.
 	 */
 	if (ci->i_snap_realm) {
 		struct ceph_mds_client *mdsc =
@@ -582,6 +581,7 @@ static int fill_inode(struct inode *inode,
 		      unsigned long ttl_from, int cap_fmode,
 		      struct ceph_cap_reservation *caps_reservation)
 {
+	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 	struct ceph_mds_reply_inode *info = iinfo->in;
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	int i;
@@ -591,7 +591,9 @@ static int fill_inode(struct inode *inode,
 	struct ceph_inode_frag *frag;
 	struct rb_node *rb_node;
 	struct ceph_buffer *xattr_blob = NULL;
+	struct ceph_cap *new_cap = NULL;
 	int err = 0;
+	bool wake = false;
 	bool queue_trunc = false;
 	bool new_version = false;
 
@@ -599,6 +601,10 @@ static int fill_inode(struct inode *inode,
 	     inode, ceph_vinop(inode), le64_to_cpu(info->version),
 	     ci->i_version);
 
+	/* prealloc new cap struct */
+	if (info->cap.caps && ceph_snap(inode) == CEPH_NOSNAP)
+		new_cap = ceph_get_cap(mdsc, caps_reservation);
+
 	/*
 	 * prealloc xattr data, if it looks like we'll need it.  only
 	 * if len > 4 (meaning there are actually xattrs; the first 4
@@ -762,8 +768,37 @@ static int fill_inode(struct inode *inode,
 		dout(" marking %p complete (empty)\n", inode);
 		__ceph_dir_set_complete(ci, atomic_read(&ci->i_release_count));
 	}
+
+	/* were we issued a capability? */
+	if (info->cap.caps) {
+		if (ceph_snap(inode) == CEPH_NOSNAP) {
+			ceph_add_cap(inode, session,
+				     le64_to_cpu(info->cap.cap_id),
+				     cap_fmode,
+				     le32_to_cpu(info->cap.caps),
+				     le32_to_cpu(info->cap.wanted),
+				     le32_to_cpu(info->cap.seq),
+				     le32_to_cpu(info->cap.mseq),
+				     le64_to_cpu(info->cap.realm),
+				     info->cap.flags, &new_cap);
+			wake = true;
+		} else {
+			dout(" %p got snap_caps %s\n", inode,
+			     ceph_cap_string(le32_to_cpu(info->cap.caps)));
+			ci->i_snap_caps |= le32_to_cpu(info->cap.caps);
+			if (cap_fmode >= 0)
+				__ceph_get_fmode(ci, cap_fmode);
+		}
+	} else if (cap_fmode >= 0) {
+		pr_warning("mds issued no caps on %llx.%llx\n",
+			   ceph_vinop(inode));
+		__ceph_get_fmode(ci, cap_fmode);
+	}
 	spin_unlock(&ci->i_ceph_lock);
 
+	if (wake)
+		wake_up_all(&ci->i_cap_wq);
+
 	/* queue truncate if we saw i_size decrease */
 	if (queue_trunc)
 		ceph_queue_vmtruncate(inode);
@@ -806,41 +841,14 @@ static int fill_inode(struct inode *inode,
 	}
 	mutex_unlock(&ci->i_fragtree_mutex);
 
-	/* were we issued a capability? */
-	if (info->cap.caps) {
-		if (ceph_snap(inode) == CEPH_NOSNAP) {
-			ceph_add_cap(inode, session,
-				     le64_to_cpu(info->cap.cap_id),
-				     cap_fmode,
-				     le32_to_cpu(info->cap.caps),
-				     le32_to_cpu(info->cap.wanted),
-				     le32_to_cpu(info->cap.seq),
-				     le32_to_cpu(info->cap.mseq),
-				     le64_to_cpu(info->cap.realm),
-				     info->cap.flags,
-				     caps_reservation);
-		} else {
-			spin_lock(&ci->i_ceph_lock);
-			dout(" %p got snap_caps %s\n", inode,
-			     ceph_cap_string(le32_to_cpu(info->cap.caps)));
-			ci->i_snap_caps |= le32_to_cpu(info->cap.caps);
-			if (cap_fmode >= 0)
-				__ceph_get_fmode(ci, cap_fmode);
-			spin_unlock(&ci->i_ceph_lock);
-		}
-	} else if (cap_fmode >= 0) {
-		pr_warning("mds issued no caps on %llx.%llx\n",
-			   ceph_vinop(inode));
-		__ceph_get_fmode(ci, cap_fmode);
-	}
-
 	/* update delegation info? */
 	if (dirinfo)
 		ceph_fill_dirfrag(inode, dirinfo);
 
 	err = 0;
-
 out:
+	if (new_cap)
+		ceph_put_cap(mdsc, new_cap);
 	if (xattr_blob)
 		ceph_buffer_put(xattr_blob);
 	return err;