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authorChuck Lever <chuck.lever@oracle.com>2019-02-11 11:24:10 -0500
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2019-02-13 11:32:45 -0500
commit5582863f450ca44c472dbf4812a62f4e0e68b0c8 (patch)
tree858903c10475686c0c203d61bc8f1b41e9c472cc /net/sunrpc/xdr.c
parent0ccc61b1c76e5163c6fea6cf83bd18e7ea244c5b (diff)
SUNRPC: Add XDR overflow trace event
This can help field troubleshooting without needing the overhead of a full network capture (ie, tcpdump). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xdr.c')
-rw-r--r--net/sunrpc/xdr.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 345f08b634ee..6d0b615a02ae 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -16,6 +16,7 @@
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/bvec.h>
+#include <trace/events/sunrpc.h>
/*
* XDR functions for basic NFS types
@@ -554,9 +555,9 @@ static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
int frag1bytes, frag2bytes;
if (nbytes > PAGE_SIZE)
- return NULL; /* Bigger buffers require special handling */
+ goto out_overflow; /* Bigger buffers require special handling */
if (xdr->buf->len + nbytes > xdr->buf->buflen)
- return NULL; /* Sorry, we're totally out of space */
+ goto out_overflow; /* Sorry, we're totally out of space */
frag1bytes = (xdr->end - xdr->p) << 2;
frag2bytes = nbytes - frag1bytes;
if (xdr->iov)
@@ -585,6 +586,9 @@ static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
xdr->buf->page_len += frag2bytes;
xdr->buf->len += nbytes;
return p;
+out_overflow:
+ trace_rpc_xdr_overflow(xdr, nbytes);
+ return NULL;
}
/**
@@ -902,20 +906,23 @@ static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
size_t cplen = (char *)xdr->end - (char *)xdr->p;
if (nbytes > xdr->scratch.iov_len)
- return NULL;
+ goto out_overflow;
p = __xdr_inline_decode(xdr, cplen);
if (p == NULL)
return NULL;
memcpy(cpdest, p, cplen);
+ if (!xdr_set_next_buffer(xdr))
+ goto out_overflow;
cpdest += cplen;
nbytes -= cplen;
- if (!xdr_set_next_buffer(xdr))
- return NULL;
p = __xdr_inline_decode(xdr, nbytes);
if (p == NULL)
return NULL;
memcpy(cpdest, p, nbytes);
return xdr->scratch.iov_base;
+out_overflow:
+ trace_rpc_xdr_overflow(xdr, nbytes);
+ return NULL;
}
/**
@@ -932,14 +939,17 @@ __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
{
__be32 *p;
- if (nbytes == 0)
+ if (unlikely(nbytes == 0))
return xdr->p;
if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
- return NULL;
+ goto out_overflow;
p = __xdr_inline_decode(xdr, nbytes);
if (p != NULL)
return p;
return xdr_copy_to_scratch(xdr, nbytes);
+out_overflow:
+ trace_rpc_xdr_overflow(xdr, nbytes);
+ return NULL;
}
EXPORT_SYMBOL_GPL(xdr_inline_decode);