> On 4 Feb 2017, at 02:03, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > v3: Squash bool to flag change patches, and better explain why we need > to use atomic *_bit calls. Vet target and parent inodes when updating > lease. Update lease properly on negative dentries (when is_target is 0). > Also, update dentry leases even when call that triggered the request > is cancelled. > > v2: Fix a hang that would occasionally occur under fsstress > > Zheng mentioned that he had gotten a report that testing with vdbench on > a v4.8 kernel showed a large increase in the number of GETATTR calls > being made. Since we had changed the d_revalidate code to use a GETATTR > call and not set r_locked_dir in the request, the dentry lease wasn't > getting updated from the traces, even when the MDS had granted one. > > We need to use a LOOKUP when revalidating dentries so we can update > the dentry lease if things look ok. That currently depends however on > having r_locked_dir set to the parent directory. > > In d_revalidate though, we may very well not hold the parent's i_rwsem. > Manipulating the dcache is not allowed without it, but we can update the > inode and the dentry leases. > > The basic approach here is to separate r_locked_dir into an inode > pointer representing the parent, and a flag indicating whether we > know that it's locked (note that it _may_ still be locked even if > that flag isn't set). > > In ceph_fill_trace, we can then do all of the parts that don't require a > locked parent whenever the parent pointer is set, but avoid the > dcache manipulation when it isn't. > > With this, dentry leases are again being updated as a result of > d_revalidate lookups. The switch to using a flags fields instead > of bools also shrinks the request size slightly. > > Jeff Layton (8): > ceph: remove "Debugging hook" from ceph_fill_trace > ceph: drop session argument to ceph_fill_trace > ceph: convert bools in ceph_mds_request to a new r_req_flags field > ceph: add a new flag to indicate whether parent is locked > ceph: don't update_dentry_lease unless we actually got one > ceph: vet the target and parent inodes before updating dentry lease > ceph: call update_dentry_lease even when r_locked dir is not set > ceph: do a LOOKUP in d_revalidate instead of GETATTR > > fs/ceph/debugfs.c | 2 +- > fs/ceph/dir.c | 30 ++++++---- > fs/ceph/export.c | 3 +- > fs/ceph/file.c | 3 +- > fs/ceph/inode.c | 164 ++++++++++++++++++++++++++++----------------------- > fs/ceph/mds_client.c | 73 ++++++++++++----------- > fs/ceph/mds_client.h | 15 +++-- > fs/ceph/super.h | 3 +- > 8 files changed, 162 insertions(+), 131 deletions(-) Besides few minor comments. This series looks good in general. Regards Yan, Zheng > > -- > 2.9.3 > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
