ceph: handle frag mismatch between readdir request and reply
If client has outdated directory fragments information, it may request
readdir an non-existent directory fragment. In this case, the MDS finds
an approximate directory fragment and sends its contents back to the
client. When receiving a reply with fragment that is different than the
requested one, the client need to reset the 'readdir offset'.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 868b61d..2a0bcae 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -352,8 +352,18 @@
}
/* note next offset and last dentry name */
+ rinfo = &req->r_reply_info;
+ if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
+ frag = le32_to_cpu(rinfo->dir_dir->frag);
+ if (ceph_frag_is_leftmost(frag))
+ fi->next_offset = 2;
+ else
+ fi->next_offset = 0;
+ off = fi->next_offset;
+ }
fi->offset = fi->next_offset;
fi->last_readdir = req;
+ fi->frag = frag;
if (req->r_reply_info.dir_end) {
kfree(fi->last_name);
@@ -363,7 +373,6 @@
else
fi->next_offset = 0;
} else {
- rinfo = &req->r_reply_info;
err = note_last_dentry(fi,
rinfo->dir_dname[rinfo->dir_nr-1],
rinfo->dir_dname_len[rinfo->dir_nr-1]);