[PATCH 6.8 020/336] NFSD: add support for CB_GETATTR callback

Greg Kroah-Hartman
2024-05-14T10:22:28Z

From: Dai Ngo <dai.ngo@oracle.com>

[ Upstream commit 6487a13b5c6bee2ca3fc931f8ad28c8ae887a41f ]

Includes:
. CB_GETATTR proc for nfs4_cb_procedures[]
. XDR encoding and decoding function for CB_GETATTR request/reply
. add nfs4_cb_fattr to nfs4_delegation for sending CB_GETATTR
and store file attributes from client's reply.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Stable-dep-of: 18180a4550d0 ("NFSD: Fix nfsd4_encode_fattr4() crasher")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfsd/nfs4callback.c | 97 +++++++++++++++++++++++++++++++++++++++++-
fs/nfsd/state.h | 14 ++++++
fs/nfsd/xdr4cb.h | 18 ++++++++
3 files changed, 128 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 926c29879c6ab..30aa241038eb4 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -85,7 +85,21 @@ static void encode_uint32(struct xdr_stream *xdr, u32 n)
static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
size_t len)
{
- WARN_ON_ONCE(xdr_stream_encode_uint32_array(xdr, bitmap, len) < 0);
+ xdr_stream_encode_uint32_array(xdr, bitmap, len);
+}
+
+static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
+ struct nfs4_cb_fattr *fattr)
+{
+ fattr->ncf_cb_change = 0;
+ fattr->ncf_cb_fsize = 0;
+ if (bitmap[0] & FATTR4_WORD0_CHANGE)
+ if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0)
+ return -NFSERR_BAD_XDR;
+ if (bitmap[0] & FATTR4_WORD0_SIZE)
+ if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0)
+ return -NFSERR_BAD_XDR;
+ return 0;
}

static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
@@ -333,6 +347,30 @@ encode_cb_recallany4args(struct xdr_stream *xdr,
hdr->nops++;
}

+/*
+ * CB_GETATTR4args
+ * struct CB_GETATTR4args {
+ * nfs_fh4 fh;
+ * bitmap4 attr_request;
+ * };
+ *
+ * The size and change attributes are the only one
+ * guaranteed to be serviced by the client.
+ */
+static void
+encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr,
+ struct nfs4_cb_fattr *fattr)
+{
+ struct nfs4_delegation *dp =
+ container_of(fattr, struct nfs4_delegation, dl_cb_fattr);
+ struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle;
+
+ encode_nfs_cb_opnum4(xdr, OP_CB_GETATTR);
+ encode_nfs_fh4(xdr, fh);
+ encode_bitmap4(xdr, fattr->ncf_cb_bmap, ARRAY_SIZE(fattr->ncf_cb_bmap));
+ hdr->nops++;
+}
+
/*
* CB_SEQUENCE4args
*
@@ -468,6 +506,26 @@ static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
xdr_reserve_space(xdr, 0);
}

+/*
+ * 20.1. Operation 3: CB_GETATTR - Get Attributes
+ */
+static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req,
+ struct xdr_stream *xdr, const void *data)
+{
+ const struct nfsd4_callback *cb = data;
+ struct nfs4_cb_fattr *ncf =
+ container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
+ struct nfs4_cb_compound_hdr hdr = {
+ .ident = cb->cb_clp->cl_cb_ident,
+ .minorversion = cb->cb_clp->cl_minorversion,
+ };
+
+ encode_cb_compound4args(xdr, &hdr);
+ encode_cb_sequence4args(xdr, cb, &hdr);
+ encode_cb_getattr4args(xdr, &hdr, ncf);
+ encode_cb_nops(&hdr);
+}
+
/*
* 20.2. Operation 4: CB_RECALL - Recall a Delegation
*/
@@ -523,6 +581,42 @@ static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
return 0;
}

+/*
+ * 20.1. Operation 3: CB_GETATTR - Get Attributes
+ */
+static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ void *data)
+{
+ struct nfsd4_callback *cb = data;
+ struct nfs4_cb_compound_hdr hdr;
+ int status;
+ u32 bitmap[3] = {0};
+ u32 attrlen;
+ struct nfs4_cb_fattr *ncf =
+ container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
+
+ status = decode_cb_compound4res(xdr, &hdr);
+ if (unlikely(status))
+ return status;
+
+ status = decode_cb_sequence4res(xdr, cb);
+ if (unlikely(status || cb->cb_seq_status))
+ return status;
+
+ status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status);
+ if (status)
+ return status;
+ if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0)
+ return -NFSERR_BAD_XDR;
+ if (xdr_stream_decode_u32(xdr, &attrlen) < 0)
+ return -NFSERR_BAD_XDR;
+ if (attrlen > (sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize)))
+ return -NFSERR_BAD_XDR;
+ status = decode_cb_fattr4(xdr, bitmap, ncf);
+ return status;
+}
+
/*
* 20.2. Operation 4: CB_RECALL - Recall a Delegation
*/
@@ -831,6 +925,7 @@ static const struct rpc_procinfo nfs4_cb_procedures[] = {
PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
+ PROC(CB_GETATTR, COMPOUND, cb_getattr, cb_getattr),
};

static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 41bdc913fa715..0bbbe57e027d3 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -117,6 +117,16 @@ struct nfs4_cpntf_state {
time64_t cpntf_time; /* last time stateid used */
};

+struct nfs4_cb_fattr {
+ struct nfsd4_callback ncf_getattr;
+ u32 ncf_cb_status;
+ u32 ncf_cb_bmap[1];
+
+ /* from CB_GETATTR reply */
+ u64 ncf_cb_change;
+ u64 ncf_cb_fsize;
+};
+
/*
* Represents a delegation stateid. The nfs4_client holds references to these
* and they are put when it is being destroyed or when the delegation is
@@ -150,6 +160,9 @@ struct nfs4_delegation {
int dl_retries;
struct nfsd4_callback dl_recall;
bool dl_recalled;
+
+ /* for CB_GETATTR */
+ struct nfs4_cb_fattr dl_cb_fattr;
};

#define cb_to_delegation(cb) \
@@ -640,6 +653,7 @@ enum nfsd4_cb_op {
NFSPROC4_CLNT_CB_SEQUENCE,
NFSPROC4_CLNT_CB_NOTIFY_LOCK,
NFSPROC4_CLNT_CB_RECALL_ANY,
+ NFSPROC4_CLNT_CB_GETATTR,
};

/* Returns true iff a is later than b: */
diff --git a/fs/nfsd/xdr4cb.h b/fs/nfsd/xdr4cb.h
index 0d39af1b00a0f..e8b00309c449f 100644
--- a/fs/nfsd/xdr4cb.h
+++ b/fs/nfsd/xdr4cb.h
@@ -54,3 +54,21 @@
#define NFS4_dec_cb_recall_any_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)
+
+/*
+ * 1: CB_GETATTR opcode (32-bit)
+ * N: file_handle
+ * 1: number of entry in attribute array (32-bit)
+ * 1: entry 0 in attribute array (32-bit)
+ */
+#define NFS4_enc_cb_getattr_sz (cb_compound_enc_hdr_sz + \
+ cb_sequence_enc_sz + \
+ 1 + enc_nfs4_fh_sz + 1 + 1)
+/*
+ * 4: fattr_bitmap_maxsz
+ * 1: attribute array len
+ * 2: change attr (64-bit)
+ * 2: size (64-bit)
+ */
+#define NFS4_dec_cb_getattr_sz (cb_compound_dec_hdr_sz + \
+ cb_sequence_dec_sz + 4 + 1 + 2 + 2 + op_dec_sz)
--
2.43.0