Attachment 155441 Details for Bug 241341 – Upstream Patch

[patch] Upstream Patch

rpc.patch (text/plain), 4.16 KB, created by Steve Dickson on 2007-05-25 10:28:50 UTC

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Creator: Steve Dickson

Created: 2007-05-25 10:28:50 UTC

Size: 4.16 KB

patch

obsolete

>commit cd123012d99fde4759500fee611e724e4f3016e3
>Author: Jeff Layton <jlayton@redhat.com>
>Date:   Wed May 9 02:34:50 2007 -0700
>
>    RPC: add wrapper for svc_reserve to account for checksum
>    
>    When the kernel calls svc_reserve to downsize the expected size of an RPC
>    reply, it fails to account for the possibility of a checksum at the end of
>    the packet.  If a client mounts a NFSv2/3 with sec=krb5i/p, and does I/O
>    then you'll generally see messages similar to this in the server's ring
>    buffer:
>    
>    RPC request reserved 164 but used 208
>    
>    While I was never able to verify it, I suspect that this problem is also
>    the root cause of some oopses I've seen under these conditions:
>    
>    https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=227726
>    
>    This is probably also a problem for other sec= types and for NFSv4.  The
>    large reserved size for NFSv4 compound packets seems to generally paper
>    over the problem, however.
>    
>    This patch adds a wrapper for svc_reserve that accounts for the possibility
>    of a checksum.  It also fixes up the appropriate callers of svc_reserve to
>    call the wrapper.  For now, it just uses a hardcoded value that I
>    determined via testing.  That value may need to be revised upward as things
>    change, or we may want to eventually add a new auth_op that attempts to
>    calculate this somehow.
>    
>    Unfortunately, there doesn't seem to be a good way to reliably determine
>    the expected checksum length prior to actually calculating it, particularly
>    with schemes like spkm3.
>    
>    Signed-off-by: Jeff Layton <jlayton@redhat.com>
>    Acked-by: Neil Brown <neilb@suse.de>
>    Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
>    Acked-by: J. Bruce Fields <bfields@citi.umich.edu>
>    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
>
>diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
>index 7f5bad0..eac8283 100644
>--- a/fs/nfsd/nfs3proc.c
>+++ b/fs/nfsd/nfs3proc.c
>@@ -177,7 +177,7 @@ nfsd3_proc_read(struct svc_rqst *rqstp, struct nfsd3_readargs *argp,
> 	if (max_blocksize < resp->count)
> 		resp->count = max_blocksize;
> 
>-	svc_reserve(rqstp, ((1 + NFS3_POST_OP_ATTR_WORDS + 3)<<2) + resp->count +4);
>+	svc_reserve_auth(rqstp, ((1 + NFS3_POST_OP_ATTR_WORDS + 3)<<2) + resp->count +4);
> 
> 	fh_copy(&resp->fh, &argp->fh);
> 	nfserr = nfsd_read(rqstp, &resp->fh, NULL,
>diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
>index 5cc2eec..b2c7147 100644
>--- a/fs/nfsd/nfsproc.c
>+++ b/fs/nfsd/nfsproc.c
>@@ -155,7 +155,7 @@ nfsd_proc_read(struct svc_rqst *rqstp, struct nfsd_readargs *argp,
> 				argp->count);
> 		argp->count = NFSSVC_MAXBLKSIZE_V2;
> 	}
>-	svc_reserve(rqstp, (19<<2) + argp->count + 4);
>+	svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
> 
> 	resp->count = argp->count;
> 	nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
>diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
>index 35fa4d5..4a7ae8a 100644
>--- a/include/linux/sunrpc/svc.h
>+++ b/include/linux/sunrpc/svc.h
>@@ -396,4 +396,23 @@ char *		   svc_print_addr(struct svc_rqst *, char *, size_t);
> 
> #define	RPC_MAX_ADDRBUFLEN	(63U)
> 
>+/*
>+ * When we want to reduce the size of the reserved space in the response
>+ * buffer, we need to take into account the size of any checksum data that
>+ * may be at the end of the packet. This is difficult to determine exactly
>+ * for all cases without actually generating the checksum, so we just use a
>+ * static value.
>+ */
>+static inline void
>+svc_reserve_auth(struct svc_rqst *rqstp, int space)
>+{
>+	int			added_space = 0;
>+
>+	switch(rqstp->rq_authop->flavour) {
>+		case RPC_AUTH_GSS:
>+			added_space = RPC_MAX_AUTH_SIZE;
>+	}
>+	return svc_reserve(rqstp, space + added_space);
>+}
>+
> #endif /* SUNRPC_SVC_H */
>diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
>index b7503c1..e673ef9 100644
>--- a/net/sunrpc/svc.c
>+++ b/net/sunrpc/svc.c
>@@ -907,7 +907,7 @@ svc_process(struct svc_rqst *rqstp)
> 	 * better idea of reply size
> 	 */
> 	if (procp->pc_xdrressize)
>-		svc_reserve(rqstp, procp->pc_xdrressize<<2);
>+		svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
> 
> 	/* Call the function that processes the request. */
> 	if (!versp->vs_dispatch) {

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Attachments on bug 241341: 155441