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authorTrond Myklebust <trond.myklebust@hammerspace.com>2022-07-27 19:27:54 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-08-25 12:09:29 +0300
commit6d8453df84f1488798b1d39a467de6349fdf3ccb (patch)
treed9aadfd600cc43347cf9bc8c22335c0583b166ed
parentd908b2604ec9e769ae275dbbf066f7dba93e92a5 (diff)
downloadlinux-6d8453df84f1488798b1d39a467de6349fdf3ccb.tar.xz
SUNRPC: Reinitialise the backchannel request buffers before reuse
commit 6622e3a73112fc336c1c2c582428fb5ef18e456a upstream. When we're reusing the backchannel requests instead of freeing them, then we should reinitialise any values of the send/receive xdr_bufs so that they reflect the available space. Fixes: 0d2a970d0ae5 ("SUNRPC: Fix a backchannel race") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/sunrpc/backchannel_rqst.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index ac701c28f44f..a441dd119533 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -69,6 +69,17 @@ static void xprt_free_allocation(struct rpc_rqst *req)
kfree(req);
}
+static void xprt_bc_reinit_xdr_buf(struct xdr_buf *buf)
+{
+ buf->head[0].iov_len = PAGE_SIZE;
+ buf->tail[0].iov_len = 0;
+ buf->pages = NULL;
+ buf->page_len = 0;
+ buf->flags = 0;
+ buf->len = 0;
+ buf->buflen = PAGE_SIZE;
+}
+
static int xprt_alloc_xdr_buf(struct xdr_buf *buf, gfp_t gfp_flags)
{
struct page *page;
@@ -291,6 +302,9 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
*/
spin_lock_bh(&xprt->bc_pa_lock);
if (xprt_need_to_requeue(xprt)) {
+ xprt_bc_reinit_xdr_buf(&req->rq_snd_buf);
+ xprt_bc_reinit_xdr_buf(&req->rq_rcv_buf);
+ req->rq_rcv_buf.len = PAGE_SIZE;
list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
xprt->bc_alloc_count++;
req = NULL;