NFSv4/pNFS: Fix a layoutget livelock loop
If NFS_LAYOUT_RETURN_REQUESTED is set, but there is no value set for
the layout plh_return_seq, we can end up in a livelock loop in which
every layout segment retrieved by a new call to layoutget is immediately
invalidated by pnfs_layout_need_return().
To get around this, we should just set plh_return_seq to the current
value of the layout stateid's seqid.
Fixes: d474f96104
("NFS: Don't return layout segments that are in use")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
parent
71d3d0ebc8
commit
e20772cbdf
|
@ -347,11 +347,15 @@ pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
|
||||||
iomode = IOMODE_ANY;
|
iomode = IOMODE_ANY;
|
||||||
lo->plh_return_iomode = iomode;
|
lo->plh_return_iomode = iomode;
|
||||||
set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
|
set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
|
||||||
if (seq != 0) {
|
/*
|
||||||
WARN_ON_ONCE(lo->plh_return_seq != 0 && lo->plh_return_seq != seq);
|
* We must set lo->plh_return_seq to avoid livelocks with
|
||||||
|
* pnfs_layout_need_return()
|
||||||
|
*/
|
||||||
|
if (seq == 0)
|
||||||
|
seq = be32_to_cpu(lo->plh_stateid.seqid);
|
||||||
|
if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
|
||||||
lo->plh_return_seq = seq;
|
lo->plh_return_seq = seq;
|
||||||
pnfs_barrier_update(lo, seq);
|
pnfs_barrier_update(lo, seq);
|
||||||
}
|
|
||||||
}
|
}
|
||||||
|
|
||||||
static void
|
static void
|
||||||
|
|
Loading…
Reference in New Issue