From 81c6aea5275eae453719d7f3924da07e668265c5 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Wed, 18 Sep 2013 09:44:13 +0800 Subject: [PATCH] ceph: handle frag mismatch between readdir request and reply If client has outdated directory fragments information, it may request readdir an non-existent directory fragment.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 Reviewed-by: Sage Weil --- fs/ceph/dir.c | 11 ++++++++++- fs/ceph/inode.c | 16 ++++++++++++++-- fs/ceph/mds_client.c | 3 +-- 3 files changed, 25 insertions(+), 5 deletions(-) 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 @@ more: } /* 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 @@ more: 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]); diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 1c9fea0..9a8e396 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1275,8 +1275,20 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, int err = 0, i; struct inode *snapdir = NULL; struct ceph_mds_request_head *rhead = req->r_request->front.iov_base; - u64 frag = le32_to_cpu(rhead->args.readdir.frag); struct ceph_dentry_info *di; + u64 r_readdir_offset = req->r_readdir_offset; + u32 frag = le32_to_cpu(rhead->args.readdir.frag); + + if (rinfo->dir_dir && + le32_to_cpu(rinfo->dir_dir->frag) != frag) { + dout("readdir_prepopulate got new frag %x -> %x\n", + frag, le32_to_cpu(rinfo->dir_dir->frag)); + frag = le32_to_cpu(rinfo->dir_dir->frag); + if (ceph_frag_is_leftmost(frag)) + r_readdir_offset = 2; + else + r_readdir_offset = 0; + } if (req->r_aborted) return readdir_prepopulate_inodes_only(req, session); @@ -1340,7 +1352,7 @@ retry_lookup: } di = dn->d_fsdata; - di->offset = ceph_make_fpos(frag, i + req->r_readdir_offset); + di->offset = ceph_make_fpos(frag, i + r_readdir_offset); /* inode */ if (dn->d_inode) { diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index b7bda5d..f51ab26 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -2238,8 +2238,7 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg) err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session); if (err == 0) { if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR || - req->r_op == CEPH_MDS_OP_LSSNAP) && - rinfo->dir_nr) + req->r_op == CEPH_MDS_OP_LSSNAP)) ceph_readdir_prepopulate(req, req->r_session); ceph_unreserve_caps(mdsc, &req->r_caps_reservation); } -- 2.7.4