Commit 4baa75ef authored by Yehuda Sadeh's avatar Yehuda Sadeh Committed by Sage Weil
Browse files

ceph: change dentry offset and position after splice_dentry 



This fixes a bug, where we had the parent list have dentries with
offsets that are not monotonically increasing, which caused the ceph
dcache_readdir to skip entries.

Signed-off-by: default avatarYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent 6a4ef481

fs/ceph/inode.c

+29 −0
Original line number Diff line number Diff line
@@ -816,6 +816,33 @@ static struct dentry *splice_dentry(struct dentry *dn, struct inode *in, 
	return dn;

}



/*

 * Set dentry's directory position based on the current dir's max, and

 * order it in d_subdirs, so that dcache_readdir behaves.

 */

static void ceph_set_dentry_offset(struct dentry *dn)

{

	struct dentry *dir = dn->d_parent;

	struct inode *inode = dn->d_parent->d_inode;

	struct ceph_dentry_info *di;



	BUG_ON(!inode);



	di = ceph_dentry(dn);



	spin_lock(&inode->i_lock);

	di->offset = ceph_inode(inode)->i_max_offset++;

	spin_unlock(&inode->i_lock);



	spin_lock(&dcache_lock);

	spin_lock(&dn->d_lock);

	list_move_tail(&dir->d_subdirs, &dn->d_u.d_child);

	dout("set_dentry_offset %p %lld (%p %p)\n", dn, di->offset,

	     dn->d_u.d_child.prev, dn->d_u.d_child.next);

	spin_unlock(&dn->d_lock);

	spin_unlock(&dcache_lock);

}



/*

 * Incorporate results into the local cache.  This is either just

 * one inode, or a directory, dentry, and possibly linked-to inode (e.g.,
@@ -987,6 +1014,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, 
				goto done;

			}

			req->r_dentry = dn;  /* may have spliced */

			ceph_set_dentry_offset(dn);

			igrab(in);

		} else if (ceph_ino(in) == vino.ino &&

			   ceph_snap(in) == vino.snap) {
@@ -1029,6 +1057,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, 
			err = PTR_ERR(dn);

			goto done;

		}

		ceph_set_dentry_offset(dn);

		req->r_dentry = dn;  /* may have spliced */

		igrab(in);

		rinfo->head->is_dentry = 1;  /* fool notrace handlers */