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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-09-04 12:46:35 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-09-04 12:59:00 -0400 |
| commit | 334a8f37115bf35e38617315a360a91ac4f2b2c6 (patch) | |
| tree | b07b98d2a766ca6faa34d80e0e2ba778a74bcc77 /fs/nfs | |
| parent | 52ec7be2e27392201adf77892ba883f68df88c99 (diff) | |
| download | lwn-334a8f37115bf35e38617315a360a91ac4f2b2c6.tar.gz lwn-334a8f37115bf35e38617315a360a91ac4f2b2c6.zip | |
pNFS: Don't forget the layout stateid if there are outstanding LAYOUTGETs
If there are outstanding LAYOUTGET rpc calls, then we want to ensure that
we keep the layout stateid around so we that don't inadvertently pick up
an old/misordered sequence id.
The race is as follows:
Client Server
====== ======
LAYOUTGET(seqid)
LAYOUTGET(seqid)
return LAYOUTGET(seqid+1)
return LAYOUTGET(seqid+2)
process LAYOUTGET(seqid+2)
forget layout
process LAYOUTGET(seqid+1)
If it forgets the layout stateid before processing seqid+1, then
the client will not check the layout->plh_barrier, and so will set
the stateid with seqid+1.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/pnfs.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index cd8b5fca33f6..2c93a85eda51 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -365,7 +365,8 @@ pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo, /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */ atomic_dec(&lo->plh_refcount); if (list_empty(&lo->plh_segs)) { - set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags); + if (atomic_read(&lo->plh_outstanding) == 0) + set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags); clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags); } rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq); |