4.9-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trond.myklebust@hammerspace.com
commit 943cff67b842839f4f35364ba2db5c2d3f025d94 upstream.
The intention of nfs4_session_set_rwsize() was to cap the r/wsize to the buffer sizes negotiated by the CREATE_SESSION. The initial code had a bug whereby we would not check the values negotiated by nfs_probe_fsinfo() (the assumption being that CREATE_SESSION will always negotiate buffer values that are sane w.r.t. the server's preferred r/wsizes) but would only check values set by the user in the 'mount' command.
The code was changed in 4.11 to _always_ set the r/wsize, meaning that we now never use the server preferred r/wsizes. This is the regression that this patch fixes. Also rename the function to nfs4_session_limit_rwsize() in order to avoid future confusion.
Fixes: 033853325fe3 (NFSv4.1 respect server's max size in CREATE_SESSION") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/nfs/nfs4client.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
--- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -988,10 +988,10 @@ EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
/* * Session has been established, and the client marked ready. - * Set the mount rsize and wsize with negotiated fore channel - * attributes which will be bound checked in nfs_server_set_fsinfo. + * Limit the mount rsize, wsize and dtsize using negotiated fore + * channel attributes. */ -static void nfs4_session_set_rwsize(struct nfs_server *server) +static void nfs4_session_limit_rwsize(struct nfs_server *server) { #ifdef CONFIG_NFS_V4_1 struct nfs4_session *sess; @@ -1004,9 +1004,11 @@ static void nfs4_session_set_rwsize(stru server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead; server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
- if (!server->rsize || server->rsize > server_resp_sz) + if (server->dtsize > server_resp_sz) + server->dtsize = server_resp_sz; + if (server->rsize > server_resp_sz) server->rsize = server_resp_sz; - if (!server->wsize || server->wsize > server_rqst_sz) + if (server->wsize > server_rqst_sz) server->wsize = server_rqst_sz; #endif /* CONFIG_NFS_V4_1 */ } @@ -1053,12 +1055,12 @@ static int nfs4_server_common_setup(stru (unsigned long long) server->fsid.minor); nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
- nfs4_session_set_rwsize(server); - error = nfs_probe_fsinfo(server, mntfh, fattr); if (error < 0) goto out;
+ nfs4_session_limit_rwsize(server); + if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN) server->namelen = NFS4_MAXNAMLEN;