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 <zyan@redhat.com>
This commit is contained in:
Yan, Zheng 2016-05-03 20:55:50 +08:00 committed by Ilya Dryomov
parent 209ae762a6
commit a407846ef7

View File

@ -10,6 +10,7 @@
#include <linux/vmalloc.h>
#include <linux/posix_acl.h>
#include <linux/random.h>
#include <linux/sort.h>
#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++) {