From 960994f5d1883b6a293f66a886cf2e42be7b8669 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Tue, 20 Oct 2026 12:13:46 -0400 Subject: [PATCH] xprtrdma: fix up the nfs/nfs-anna merge of the Write chunk head trim Two fixes for the same Write chunk payload corruption meet in linux-next. In the nfs tree, commit a0db57fee35e ("xprtrdma: Fix Write chunk payload corruption on a short reply header") trims head[0].iov_len in rpcrdma_decode_msg(). In the nfs-anna tree, commit 9ee534a75912 ("xprtrdma: trim head iovec when the payload arrives via a Write chunk") trims it in rpcrdma_inline_fixup() and reduces buflen by the same amount. The merge resolution keeps the caller-side trim. By the time rpcrdma_inline_fixup() runs, head[0].iov_len already equals copy_len, so the block added by the nfs-anna commit never runs and its buflen reduction in rq_rcv_buf and rq_private_buf is lost. The helper is also still passed xdr_pad_size(writelist), while its kernel-doc now describes @writelist as the number of bytes conveyed by the Write chunk. Drop the caller-side trim and pass the full Write chunk length, so that rpcrdma_inline_fixup() is the only place that trims head[0] and reduces buflen. Compute the pad with xdr_pad_size() in the helper, so the padding from the nfs commit stays correct for lengths that are not a multiple of four. Its rpclen calculation and empty reply check stay in rpcrdma_decode_msg(). Fixes: 53ab189bdc14 ("Merge branch 'linux-next' of git://git.linux-nfs.org/projects/anna/linux-nfs.git") Link: https://lore.kernel.org/all/as4aacUf2Q78FMvY@sirena.org.uk/ Signed-off-by: Sasha Levin Tested-by: Tim Menninger Reviewed-by: Tim Menninger Signed-off-by: Linus Torvalds --- net/sunrpc/xprtrdma/rpc_rdma.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index c0d5042f3b66..69d4e35d49ef 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1010,7 +1010,7 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, char *destp; struct page **ppages; int page_base; - int pad = writelist & 3; + int pad = xdr_pad_size(writelist); unsigned int delta; /* The head iovec is redirected to the RPC reply message @@ -1267,14 +1267,9 @@ rpcrdma_decode_msg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep, rpclen &= ~3; if (unlikely(!rpclen)) return -EIO; - if (writelist && rpclen < rqst->rq_rcv_buf.head[0].iov_len) { - rqst->rq_rcv_buf.head[0].iov_len = rpclen; - rqst->rq_private_buf.head[0].iov_len = rpclen; - } r_xprt->rx_stats.fixup_copy_count += - rpcrdma_inline_fixup(rqst, base, rpclen, - xdr_pad_size(writelist)); + rpcrdma_inline_fixup(rqst, base, rpclen, writelist); r_xprt->rx_stats.total_rdma_reply += writelist; return rpclen + xdr_align_size(writelist);