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Commit f72f9455 authored by Yan, Zheng's avatar Yan, Zheng Committed by Ilya Dryomov
Browse files

ceph: fix readdir vs fragmentation race 

following sequence of events tigger the race

- client readdir frag 0* -> got item 'A'
- MDS merges frag 0* and frag 1*
- client send readdir request (frag 1*, offset 2, readdir_start 'A')
- MDS reply items (that are after item 'A') in frag *

Link: http://tracker.ceph.com/issues/17286


Signed-off-by: default avatarYan, Zheng <zyan@redhat.com>
parent 0d7718f6

fs/ceph/inode.c

+2 −1
Original line number Diff line number Diff line
@@ -1511,7 +1511,8 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, 
			ceph_fill_dirfrag(d_inode(parent), rinfo->dir_dir);

	}



	if (ceph_frag_is_leftmost(frag) && req->r_readdir_offset == 2) {

	if (ceph_frag_is_leftmost(frag) && req->r_readdir_offset == 2 &&

	    !(rinfo->hash_order && req->r_path2)) {

		/* note dir version at start of readdir so we can tell

		 * if any dentries get dropped */

		req->r_dir_release_cnt = atomic64_read(&ci->i_release_count);