From: Andy Adamson <andros@xxxxxxxxxx> At the Bakeathon, Jorge noted that when the MDS and DS use the same struct nfs_client, umount would fail to free the nfs_client struct and the keep-alive SEQUENCE compound would continue ad infinitum. This was due to the fact that the DS reference to the MDS nfs_client would prevent the umount from dropping the cl_count to zero. Moreover, the DS refererence is only dropped by the deviceid dereference only called by nfs4_deviceid_purge_client from nfs_free_client when the nfs_client cl_count was zero. See the patch comments for the solution description. I've tested this solution against a 2-node C-mode filer where one node is an MDS/DS and the other node a standalone MDS but uses the first node as a DS. I tested all combinations, including mounting the MDS/DS node, and using pNFS for I/O. Then mounting the solo MDS node, and using pNFS for I/O (which uses the MDS/DS node as a DS), then umounting one of the mount points, doing pNFS I/O and then umount the other. In all cases, umount destroyed the appropriate nfs_client, and associated session. Andy Adamson (1): NFSv4.1 Fix umount when filelayout DS is also the MDS fs/nfs/client.c | 71 ++++++++++++++++++++++++++++++++++++++++++-- fs/nfs/internal.h | 1 + fs/nfs/nfs4filelayoutdev.c | 29 +++++++++++++++-- include/linux/nfs_fs_sb.h | 1 + 4 files changed, 95 insertions(+), 7 deletions(-) -- 1.7.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
