nfsd41: try to check reply size before operation
For checking the size of reply before calling a operation,
we need try to get maxsize of the operation's reply.
v3: using new method as Bruce said,
"we could handle operations in two different ways:
- For operations that actually change something (write, rename,
open, close, ...), do it the way we're doing it now: be
very careful to estimate the size of the response before even
processing the operation.
- For operations that don't change anything (read, getattr, ...)
just go ahead and do the operation. If you realize after the
fact that the response is too large, then return the error at
that point.
So we'd add another flag to op_flags: say, OP_MODIFIES_SOMETHING. And for
operations with OP_MODIFIES_SOMETHING set, we'd do the first thing. For
operations without it set, we'd do the second."
Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
[bfields@redhat.com: crash, don't attempt to handle, undefined op_rsize_bop]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 460eeb3..752a367 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -35,6 +35,7 @@
#include <linux/file.h>
#include <linux/slab.h>
+#include "idmap.h"
#include "cache.h"
#include "xdr4.h"
#include "vfs.h"
@@ -1003,6 +1004,8 @@
typedef __be32(*nfsd4op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
void *);
+typedef u32(*nfsd4op_rsize)(struct svc_rqst *, struct nfsd4_op *op);
+
enum nfsd4_op_flags {
ALLOWED_WITHOUT_FH = 1 << 0, /* No current filehandle required */
ALLOWED_ON_ABSENT_FS = 1 << 1, /* ops processed on absent fs */
@@ -1010,6 +1013,7 @@
/* For rfc 5661 section 2.6.3.1.1: */
OP_HANDLES_WRONGSEC = 1 << 3,
OP_IS_PUTFH_LIKE = 1 << 4,
+ OP_MODIFIES_SOMETHING = 1 << 5, /* op is non-idempotent */
};
struct nfsd4_operation {
@@ -1025,6 +1029,8 @@
* the v4.0 case).
*/
bool op_cacheresult;
+ /* Try to get response size before operation */
+ nfsd4op_rsize op_rsize_bop;
};
static struct nfsd4_operation nfsd4_ops[];
@@ -1119,6 +1125,7 @@
struct nfsd4_operation *opdesc;
struct nfsd4_compound_state *cstate = &resp->cstate;
int slack_bytes;
+ u32 plen = 0;
__be32 status;
resp->xbuf = &rqstp->rq_res;
@@ -1197,6 +1204,15 @@
goto encode_op;
}
+ /* If op is non-idempotent */
+ if (opdesc->op_flags & OP_MODIFIES_SOMETHING) {
+ plen = opdesc->op_rsize_bop(rqstp, op);
+ op->status = nfsd4_check_resp_size(resp, plen);
+ }
+
+ if (op->status)
+ goto encode_op;
+
if (opdesc->op_func)
op->status = opdesc->op_func(rqstp, cstate, &op->u);
else
@@ -1247,6 +1263,144 @@
return status;
}
+#define op_encode_hdr_size (2)
+#define op_encode_stateid_maxsz (XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define op_encode_verifier_maxsz (XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define op_encode_change_info_maxsz (5)
+#define nfs4_fattr_bitmap_maxsz (4)
+
+#define op_encode_lockowner_maxsz (1 + XDR_QUADLEN(IDMAP_NAMESZ))
+#define op_encode_lock_denied_maxsz (8 + op_encode_lockowner_maxsz)
+
+#define nfs4_owner_maxsz (1 + XDR_QUADLEN(IDMAP_NAMESZ))
+
+#define op_encode_ace_maxsz (3 + nfs4_owner_maxsz)
+#define op_encode_delegation_maxsz (1 + op_encode_stateid_maxsz + 1 + \
+ op_encode_ace_maxsz)
+
+#define op_encode_channel_attrs_maxsz (6 + 1 + 1)
+
+static inline u32 nfsd4_only_status_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_status_stateid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_stateid_maxsz)* sizeof(__be32);
+}
+
+static inline u32 nfsd4_commit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_create_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_change_info_maxsz
+ + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_link_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_change_info_maxsz)
+ * sizeof(__be32);
+}
+
+static inline u32 nfsd4_lock_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_lock_denied_maxsz)
+ * sizeof(__be32);
+}
+
+static inline u32 nfsd4_open_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_stateid_maxsz
+ + op_encode_change_info_maxsz + 1
+ + nfs4_fattr_bitmap_maxsz
+ + op_encode_delegation_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_read_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ u32 maxcount = 0, rlen = 0;
+
+ maxcount = svc_max_payload(rqstp);
+ rlen = op->u.read.rd_length;
+
+ if (rlen > maxcount)
+ rlen = maxcount;
+
+ return (op_encode_hdr_size + 2) * sizeof(__be32) + rlen;
+}
+
+static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ u32 rlen = op->u.readdir.rd_maxcount;
+
+ if (rlen > PAGE_SIZE)
+ rlen = PAGE_SIZE;
+
+ return (op_encode_hdr_size + op_encode_verifier_maxsz)
+ * sizeof(__be32) + rlen;
+}
+
+static inline u32 nfsd4_remove_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_change_info_maxsz)
+ * sizeof(__be32);
+}
+
+static inline u32 nfsd4_rename_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_change_info_maxsz
+ + op_encode_change_info_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_setattr_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_setclientid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + 2 + 1024) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_write_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_exchange_id_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + 2 + 1 + /* eir_clientid, eir_sequenceid */\
+ 1 + 1 + 0 + /* eir_flags, spr_how, SP4_NONE (for now) */\
+ 2 + /*eir_server_owner.so_minor_id */\
+ /* eir_server_owner.so_major_id<> */\
+ XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
+ /* eir_server_scope<> */\
+ XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
+ 1 + /* eir_server_impl_id array length */\
+ 0 /* ignored eir_server_impl_id contents */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_bind_conn_to_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + \
+ XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* bctsr_sessid */\
+ 2 /* bctsr_dir, use_conn_in_rdma_mode */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_create_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+ return (op_encode_hdr_size + \
+ XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* sessionid */\
+ 2 + /* csr_sequence, csr_flags */\
+ op_encode_channel_attrs_maxsz + \
+ op_encode_channel_attrs_maxsz) * sizeof(__be32);
+}
+
static struct nfsd4_operation nfsd4_ops[] = {
[OP_ACCESS] = {
.op_func = (nfsd4op_func)nfsd4_access,
@@ -1254,20 +1408,28 @@
},
[OP_CLOSE] = {
.op_func = (nfsd4op_func)nfsd4_close,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_CLOSE",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
},
[OP_COMMIT] = {
.op_func = (nfsd4op_func)nfsd4_commit,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_COMMIT",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_commit_rsize,
},
[OP_CREATE] = {
.op_func = (nfsd4op_func)nfsd4_create,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_CREATE",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_create_rsize,
},
[OP_DELEGRETURN] = {
.op_func = (nfsd4op_func)nfsd4_delegreturn,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_DELEGRETURN",
+ .op_rsize_bop = nfsd4_only_status_rsize,
},
[OP_GETATTR] = {
.op_func = (nfsd4op_func)nfsd4_getattr,
@@ -1280,12 +1442,16 @@
},
[OP_LINK] = {
.op_func = (nfsd4op_func)nfsd4_link,
+ .op_flags = ALLOWED_ON_ABSENT_FS | OP_MODIFIES_SOMETHING,
.op_name = "OP_LINK",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_link_rsize,
},
[OP_LOCK] = {
.op_func = (nfsd4op_func)nfsd4_lock,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_LOCK",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_lock_rsize,
},
[OP_LOCKT] = {
.op_func = (nfsd4op_func)nfsd4_lockt,
@@ -1293,7 +1459,9 @@
},
[OP_LOCKU] = {
.op_func = (nfsd4op_func)nfsd4_locku,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_LOCKU",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
},
[OP_LOOKUP] = {
.op_func = (nfsd4op_func)nfsd4_lookup,
@@ -1311,42 +1479,54 @@
},
[OP_OPEN] = {
.op_func = (nfsd4op_func)nfsd4_open,
- .op_flags = OP_HANDLES_WRONGSEC,
+ .op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
.op_name = "OP_OPEN",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_open_rsize,
},
[OP_OPEN_CONFIRM] = {
.op_func = (nfsd4op_func)nfsd4_open_confirm,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_OPEN_CONFIRM",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
},
[OP_OPEN_DOWNGRADE] = {
.op_func = (nfsd4op_func)nfsd4_open_downgrade,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_OPEN_DOWNGRADE",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
},
[OP_PUTFH] = {
.op_func = (nfsd4op_func)nfsd4_putfh,
.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
- | OP_IS_PUTFH_LIKE,
+ | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
.op_name = "OP_PUTFH",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_PUTPUBFH] = {
.op_func = (nfsd4op_func)nfsd4_putrootfh,
.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
- | OP_IS_PUTFH_LIKE,
+ | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
.op_name = "OP_PUTPUBFH",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_PUTROOTFH] = {
.op_func = (nfsd4op_func)nfsd4_putrootfh,
.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
- | OP_IS_PUTFH_LIKE,
+ | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
.op_name = "OP_PUTROOTFH",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_READ] = {
.op_func = (nfsd4op_func)nfsd4_read,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_READ",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_read_rsize,
},
[OP_READDIR] = {
.op_func = (nfsd4op_func)nfsd4_readdir,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_READDIR",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_readdir_rsize,
},
[OP_READLINK] = {
.op_func = (nfsd4op_func)nfsd4_readlink,
@@ -1354,29 +1534,38 @@
},
[OP_REMOVE] = {
.op_func = (nfsd4op_func)nfsd4_remove,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_REMOVE",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_remove_rsize,
},
[OP_RENAME] = {
- .op_name = "OP_RENAME",
.op_func = (nfsd4op_func)nfsd4_rename,
+ .op_flags = OP_MODIFIES_SOMETHING,
+ .op_name = "OP_RENAME",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_rename_rsize,
},
[OP_RENEW] = {
.op_func = (nfsd4op_func)nfsd4_renew,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_RENEW",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
+
},
[OP_RESTOREFH] = {
.op_func = (nfsd4op_func)nfsd4_restorefh,
.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
- | OP_IS_PUTFH_LIKE,
+ | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
.op_name = "OP_RESTOREFH",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_SAVEFH] = {
.op_func = (nfsd4op_func)nfsd4_savefh,
- .op_flags = OP_HANDLES_WRONGSEC,
+ .op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
.op_name = "OP_SAVEFH",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_SECINFO] = {
.op_func = (nfsd4op_func)nfsd4_secinfo,
@@ -1386,19 +1575,25 @@
[OP_SETATTR] = {
.op_func = (nfsd4op_func)nfsd4_setattr,
.op_name = "OP_SETATTR",
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_setattr_rsize,
},
[OP_SETCLIENTID] = {
.op_func = (nfsd4op_func)nfsd4_setclientid,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_SETCLIENTID",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_setclientid_rsize,
},
[OP_SETCLIENTID_CONFIRM] = {
.op_func = (nfsd4op_func)nfsd4_setclientid_confirm,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_SETCLIENTID_CONFIRM",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_VERIFY] = {
.op_func = (nfsd4op_func)nfsd4_verify,
@@ -1406,35 +1601,47 @@
},
[OP_WRITE] = {
.op_func = (nfsd4op_func)nfsd4_write,
+ .op_flags = OP_MODIFIES_SOMETHING,
.op_name = "OP_WRITE",
.op_cacheresult = true,
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_write_rsize,
},
[OP_RELEASE_LOCKOWNER] = {
.op_func = (nfsd4op_func)nfsd4_release_lockowner,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_RELEASE_LOCKOWNER",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
/* NFSv4.1 operations */
[OP_EXCHANGE_ID] = {
.op_func = (nfsd4op_func)nfsd4_exchange_id,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_EXCHANGE_ID",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_exchange_id_rsize,
},
[OP_BIND_CONN_TO_SESSION] = {
.op_func = (nfsd4op_func)nfsd4_bind_conn_to_session,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_BIND_CONN_TO_SESSION",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_bind_conn_to_session_rsize,
},
[OP_CREATE_SESSION] = {
.op_func = (nfsd4op_func)nfsd4_create_session,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_CREATE_SESSION",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_create_session_rsize,
},
[OP_DESTROY_SESSION] = {
.op_func = (nfsd4op_func)nfsd4_destroy_session,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_DESTROY_SESSION",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_SEQUENCE] = {
.op_func = (nfsd4op_func)nfsd4_sequence,
@@ -1443,13 +1650,16 @@
},
[OP_DESTROY_CLIENTID] = {
.op_func = NULL,
- .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+ .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+ | OP_MODIFIES_SOMETHING,
.op_name = "OP_DESTROY_CLIENTID",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_RECLAIM_COMPLETE] = {
.op_func = (nfsd4op_func)nfsd4_reclaim_complete,
- .op_flags = ALLOWED_WITHOUT_FH,
+ .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
.op_name = "OP_RECLAIM_COMPLETE",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
[OP_SECINFO_NO_NAME] = {
.op_func = (nfsd4op_func)nfsd4_secinfo_no_name,
@@ -1463,8 +1673,9 @@
},
[OP_FREE_STATEID] = {
.op_func = (nfsd4op_func)nfsd4_free_stateid,
- .op_flags = ALLOWED_WITHOUT_FH,
+ .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
.op_name = "OP_FREE_STATEID",
+ .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
};