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authorChuck Lever <chuck.lever@oracle.com>2013-10-17 14:12:50 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2013-10-28 15:24:00 -0400
commitb03d735b4ca2375d2251195cd848713bc55e7d79 (patch)
tree5c351a0fbdc47022c74c7db5a9f80235f9105f6a /fs/nfs/nfs4xdr.c
parent9e6ee76dfb7cd747fac5679542a9b45930173eec (diff)
NFS: Add method to retrieve fs_locations during migration recovery
The nfs4_proc_fs_locations() function is invoked during referral processing to perform a GETATTR(fs_locations) on an object's parent directory in order to discover the target of the referral. It performs a LOOKUP in the compound, so the client needs to know the parent's file handle a priori. Unfortunately this function is not adequate for handling migration recovery. We need to probe fs_locations information on an FSID, but there's no parent directory available for many operations that can return NFS4ERR_MOVED. Another subtlety: recovering from NFS4ERR_LEASE_MOVED is a process of walking over a list of known FSIDs that reside on the server, and probing whether they have migrated. Once the server has detected that the client has probed all migrated file systems, it stops returning NFS4ERR_LEASE_MOVED. A minor version zero server needs to know what client ID is requesting fs_locations information so it can clear the flag that forces it to continue returning NFS4ERR_LEASE_MOVED. This flag is set per client ID and per FSID. However, the client ID is not an argument of either the PUTFH or GETATTR operations. Later minor versions have client ID information embedded in the compound's SEQUENCE operation. Therefore, by convention, minor version zero clients send a RENEW operation in the same compound as the GETATTR(fs_locations), since RENEW's one argument is a clientid4. This allows a minor version zero server to identify correctly the client that is probing for a migration. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4xdr.c')
-rw-r--r--fs/nfs/nfs4xdr.c46
1 files changed, 35 insertions, 11 deletions
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 79210d23f607..1854b04f828f 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -736,13 +736,15 @@ static int nfs4_stat_to_errno(int);
encode_sequence_maxsz + \
encode_putfh_maxsz + \
encode_lookup_maxsz + \
- encode_fs_locations_maxsz)
+ encode_fs_locations_maxsz + \
+ encode_renew_maxsz)
#define NFS4_dec_fs_locations_sz \
(compound_decode_hdr_maxsz + \
decode_sequence_maxsz + \
decode_putfh_maxsz + \
decode_lookup_maxsz + \
- decode_fs_locations_maxsz)
+ decode_fs_locations_maxsz + \
+ decode_renew_maxsz)
#define NFS4_enc_secinfo_sz (compound_encode_hdr_maxsz + \
encode_sequence_maxsz + \
encode_putfh_maxsz + \
@@ -2687,11 +2689,20 @@ static void nfs4_xdr_enc_fs_locations(struct rpc_rqst *req,
encode_compound_hdr(xdr, req, &hdr);
encode_sequence(xdr, &args->seq_args, &hdr);
- encode_putfh(xdr, args->dir_fh, &hdr);
- encode_lookup(xdr, args->name, &hdr);
- replen = hdr.replen; /* get the attribute into args->page */
- encode_fs_locations(xdr, args->bitmask, &hdr);
+ if (args->migration) {
+ encode_putfh(xdr, args->fh, &hdr);
+ replen = hdr.replen;
+ encode_fs_locations(xdr, args->bitmask, &hdr);
+ if (args->renew)
+ encode_renew(xdr, args->clientid, &hdr);
+ } else {
+ encode_putfh(xdr, args->dir_fh, &hdr);
+ encode_lookup(xdr, args->name, &hdr);
+ replen = hdr.replen;
+ encode_fs_locations(xdr, args->bitmask, &hdr);
+ }
+ /* Set up reply kvec to capture returned fs_locations array. */
xdr_inline_pages(&req->rq_rcv_buf, replen << 2, &args->page,
0, PAGE_SIZE);
encode_nops(&hdr);
@@ -6824,13 +6835,26 @@ static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req,
status = decode_putfh(xdr);
if (status)
goto out;
- status = decode_lookup(xdr);
- if (status)
- goto out;
- xdr_enter_page(xdr, PAGE_SIZE);
- status = decode_getfattr_generic(xdr, &res->fs_locations->fattr,
+ if (res->migration) {
+ xdr_enter_page(xdr, PAGE_SIZE);
+ status = decode_getfattr_generic(xdr,
+ &res->fs_locations->fattr,
NULL, res->fs_locations,
NULL, res->fs_locations->server);
+ if (status)
+ goto out;
+ if (res->renew)
+ status = decode_renew(xdr);
+ } else {
+ status = decode_lookup(xdr);
+ if (status)
+ goto out;
+ xdr_enter_page(xdr, PAGE_SIZE);
+ status = decode_getfattr_generic(xdr,
+ &res->fs_locations->fattr,
+ NULL, res->fs_locations,
+ NULL, res->fs_locations->server);
+ }
out:
return status;
}