Currently GETATTR conflict with a write delegation is handled by
recalling the delegation before replying to the GETATTR.
This patch series add supports for CB_GETATTR callback to get the latest
change_info and size information of the file from the client that holds
the delegation to reply to the GETATTR from the second client.
NOTE: this patch series is mostly the same as the previous patches which
were backed out when un unrelated problem of NFSD server hang on reboot
was reported.
The only difference is the wait_on_bit() in nfsd4_deleg_getattr_conflict was
replaced with wait_on_bit_timeout() with 30ms timeout to avoid a potential
DOS attack by exhausting NFSD kernel threads with GETATTR conflicts.
v2:
. update comments in nfsd4_deleg_getattr_conflict
fs/nfsd/nfs4callback.c | 97 +++++++++++++++++++++++++++++++++++-
fs/nfsd/nfs4state.c | 119 ++++++++++++++++++++++++++++++++++++++++----
fs/nfsd/nfs4xdr.c | 10 +++-
fs/nfsd/nfsd.h | 1 +
fs/nfsd/state.h | 24 ++++++++-
fs/nfsd/xdr4cb.h | 18 +++++++
6 files changed, 255 insertions(+), 14 deletions(-)
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 <[email protected]>
---
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 926c29879c6a..30aa241038eb 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 41bdc913fa71..0bbbe57e027d 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 0d39af1b00a0..e8b00309c449 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)
--
2.39.3