2021-07-23 12:58:45

by trondmy

[permalink] [raw]
Subject: [PATCH 1/2] NFSv4/pNFS: Always allow update of a zero valued layout barrier

From: Trond Myklebust <[email protected]>

A zero value for the layout barrier indicates that it has been cleared
(since seqid '0' is an illegal value), so we should always allow it to
be updated.

Fixes: d29b468da4f9 ("pNFS/NFSv4: Improve rejection of out-of-order layouts")
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pnfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index ef14ea0b6ab8..4e69e4e6c416 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -335,7 +335,7 @@ static bool pnfs_seqid_is_newer(u32 s1, u32 s2)

static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
{
- if (pnfs_seqid_is_newer(newseq, lo->plh_barrier))
+ if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
lo->plh_barrier = newseq;
}

--
2.31.1


2021-07-23 12:59:43

by trondmy

[permalink] [raw]
Subject: [PATCH 2/2] NFSv4/pnfs: The layout barrier indicate a minimal value for the seqid

From: Trond Myklebust <[email protected]>

The intention of the layout barrier is to ensure that we do not update
the layout to match an older value than the current expectation. Fix the
test in pnfs_layout_stateid_blocked() to reflect that it is legal for
the seqid of the stateid to match that of the barrier.

Fixes: aa95edf309ef ("NFSv4/pnfs: Fix the layout barrier update")
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pnfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 4e69e4e6c416..4ed4586bc1a2 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1000,7 +1000,7 @@ pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
{
u32 seqid = be32_to_cpu(stateid->seqid);

- return !pnfs_seqid_is_newer(seqid, lo->plh_barrier) && lo->plh_barrier;
+ return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
}

/* lget is set to 1 if called from inside send_layoutget call chain */
--
2.31.1