From a407846ef7c6e7905ab0d1ebc0c86fbebb065b87 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Tue, 3 May 2016 20:55:50 +0800 Subject: [PATCH] ceph: don't assume frag tree splits in mds reply are sorted The algorithm that updates i_fragtree relies on that the frag tree splits in mds reply are of the same order of i_fragtree. This is not true because current MDS encodes frag tree splits in ascending order of (unsigned)frag_t. But nodes in i_fragtree are sorted according to ceph_frag_compare(). The fix is sort the frag tree splits first, then updates i_fragtree. Signed-off-by: Yan, Zheng --- fs/ceph/inode.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 4889aaa72acc..d91eb6b49259 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "super.h" #include "mds_client.h" @@ -299,6 +300,13 @@ out: return err; } +static int frag_tree_split_cmp(const void *l, const void *r) +{ + struct ceph_frag_tree_split *ls = (struct ceph_frag_tree_split*)l; + struct ceph_frag_tree_split *rs = (struct ceph_frag_tree_split*)r; + return ceph_frag_compare(ls->frag, rs->frag); +} + static int ceph_fill_fragtree(struct inode *inode, struct ceph_frag_tree_head *fragtree, struct ceph_mds_reply_dirfrag *dirinfo) @@ -331,6 +339,11 @@ static int ceph_fill_fragtree(struct inode *inode, if (!update) goto out_unlock; + if (nsplits > 1) { + sort(fragtree->splits, nsplits, sizeof(fragtree->splits[0]), + frag_tree_split_cmp, NULL); + } + dout("fill_fragtree %llx.%llx\n", ceph_vinop(inode)); rb_node = rb_first(&ci->i_fragtree); for (i = 0; i < nsplits; i++) { -- 2.20.1