Clamp the layout barrier sequence id to the current sequence id
minus the maximum number of outstanding layoutget requests.
Also ensure that we correctly initialise lo->plh_barrier if there are
no layout segments associated to this layout header.
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
fs/nfs/pnfs.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 42613bd..861dd97 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -563,28 +563,23 @@ void
pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
bool update_barrier)
{
- u32 oldseq, newseq;
+ u32 oldseq, newseq, new_barrier;
+ int empty = list_empty(&lo->plh_segs);
oldseq = be32_to_cpu(lo->plh_stateid.seqid);
newseq = be32_to_cpu(new->seqid);
- if (list_empty(&lo->plh_segs) || pnfs_seqid_is_newer(newseq, oldseq)) {
+ if (empty || pnfs_seqid_is_newer(newseq, oldseq)) {
nfs4_stateid_copy(&lo->plh_stateid, new);
if (update_barrier) {
- u32 new_barrier = be32_to_cpu(new->seqid);
-
- if (pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
- lo->plh_barrier = new_barrier;
+ new_barrier = be32_to_cpu(new->seqid);
} else {
/* Because of wraparound, we want to keep the barrier
- * "close" to the current seqids. It needs to be
- * within 2**31 to count as "behind", so if it
- * gets too near that limit, give us a litle leeway
- * and bring it to within 2**30.
- * NOTE - and yes, this is all unsigned arithmetic.
+ * "close" to the current seqids.
*/
- if (unlikely((newseq - lo->plh_barrier) > (3 << 29)))
- lo->plh_barrier = newseq - (1 << 30);
+ new_barrier = newseq - atomic_read(&lo->plh_outstanding);
}
+ if (empty || pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
+ lo->plh_barrier = new_barrier;
}
}
--
1.7.11.4
--
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