NFSD: Rework encoding and decoding of nfsd4_deviceid

[ Upstream commit 832738e4b325b742940761e10487403f9aad13e8 ]

Compilers may optimize the layout of C structures, so we should not rely
on sizeof struct and memcpy to encode and decode XDR structures. The byte
order of the fields should also be taken into account.

This patch adds the correct functions to handle the deviceid4 structure
and removes the pad field, which is currently not used by NFSD, from the
runtime state. The server's byte order is preserved because the deviceid4
blob on the wire is only used as a cookie by the client.

Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Stable-dep-of: d68886bae76a ("NFSD: Fix last write offset handling in layoutcommit")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfsd/blocklayoutxdr.c b/fs/nfsd/blocklayoutxdr.c
index bcf21fde9120776daf4a4fa8c19740499fdba4f7..18de37ff289166d2cb7b2bf61d290cfd450bcc2e 100644 (file)
--- a/fs/nfsd/blocklayoutxdr.c
+++ b/fs/nfsd/blocklayoutxdr.c
@@ -29,8 +29,7 @@ nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
        *p++ = cpu_to_be32(len);
        *p++ = cpu_to_be32(1);          /* we always return a single extent */
 
-       p = xdr_encode_opaque_fixed(p, &b->vol_id,
-                       sizeof(struct nfsd4_deviceid));
+       p = svcxdr_encode_deviceid4(p, &b->vol_id);
        p = xdr_encode_hyper(p, b->foff);
        p = xdr_encode_hyper(p, b->len);
        p = xdr_encode_hyper(p, b->soff);
@@ -156,9 +155,7 @@ nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
        for (i = 0; i < nr_iomaps; i++) {
                struct pnfs_block_extent bex;
 
-               memcpy(&bex.vol_id, p, sizeof(struct nfsd4_deviceid));
-               p += XDR_QUADLEN(sizeof(struct nfsd4_deviceid));
-
+               p = svcxdr_decode_deviceid4(p, &bex.vol_id);
                p = xdr_decode_hyper(p, &bex.foff);
                if (bex.foff & (block_size - 1)) {
                        goto fail;

diff --git a/fs/nfsd/flexfilelayoutxdr.c b/fs/nfsd/flexfilelayoutxdr.c
index aeb71c10ff1b963fdc3370a7d8f15cc14769c4d9..f9f7e38cba13fb53850cc57a4ad31c789dcb042d 100644 (file)
--- a/fs/nfsd/flexfilelayoutxdr.c
+++ b/fs/nfsd/flexfilelayoutxdr.c
@@ -54,8 +54,7 @@ nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
        *p++ = cpu_to_be32(1);                  /* single mirror */
        *p++ = cpu_to_be32(1);                  /* single data server */
 
-       p = xdr_encode_opaque_fixed(p, &fl->deviceid,
-                       sizeof(struct nfsd4_deviceid));
+       p = svcxdr_encode_deviceid4(p, &fl->deviceid);
 
        *p++ = cpu_to_be32(1);                  /* efficiency */
 

diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index fbfddd3c4c943c34aa3991328eacb5759e311cc4..fc5e82eddaa1af9620816fc16cb711968738aefd 100644 (file)
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -120,7 +120,6 @@ nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
 
        id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
        id->generation = device_generation;
-       id->pad = 0;
        return 0;
 }
 

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 90db900b346ce9e0915473a607eee87f3db2affb..bd5c8720ea7e365defdceb105a6f5e3073295d6c 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -566,18 +566,6 @@ nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
 }
 
 #ifdef CONFIG_NFSD_PNFS
-static __be32
-nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
-                      struct nfsd4_deviceid *devid)
-{
-       __be32 *p;
-
-       p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
-       if (!p)
-               return nfserr_bad_xdr;
-       memcpy(devid, p, sizeof(*devid));
-       return nfs_ok;
-}
 
 static __be32
 nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
@@ -1762,7 +1750,7 @@ nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
        __be32 status;
 
        memset(gdev, 0, sizeof(*gdev));
-       status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
+       status = nfsd4_decode_deviceid4(argp->xdr, &gdev->gd_devid);
        if (status)
                return status;
        if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)

diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 2a21a7662e030cbd0f54060edd2b91e4d8c86d7e..83263bff27dc61ea718c4d3cf74cdd0186c6af2b 100644 (file)
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -596,9 +596,43 @@ struct nfsd4_reclaim_complete {
 struct nfsd4_deviceid {
        u64                     fsid_idx;
        u32                     generation;
-       u32                     pad;
 };
 
+static inline __be32 *
+svcxdr_encode_deviceid4(__be32 *p, const struct nfsd4_deviceid *devid)
+{
+       __be64 *q = (__be64 *)p;
+
+       *q = (__force __be64)devid->fsid_idx;
+       p += 2;
+       *p++ = (__force __be32)devid->generation;
+       *p++ = xdr_zero;
+       return p;
+}
+
+static inline __be32 *
+svcxdr_decode_deviceid4(__be32 *p, struct nfsd4_deviceid *devid)
+{
+       __be64 *q = (__be64 *)p;
+
+       devid->fsid_idx = (__force u64)(*q);
+       p += 2;
+       devid->generation = (__force u32)(*p++);
+       p++; /* NFSD does not use the remaining octets */
+       return p;
+}
+
+static inline __be32
+nfsd4_decode_deviceid4(struct xdr_stream *xdr, struct nfsd4_deviceid *devid)
+{
+       __be32 *p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
+
+       if (unlikely(!p))
+               return nfserr_bad_xdr;
+       svcxdr_decode_deviceid4(p, devid);
+       return nfs_ok;
+}
+
 struct nfsd4_layout_seg {
        u32                     iomode;
        u64                     offset;