Commit 5405fc44 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

NFSv4.x: Add kernel parameter to control the callback server 



Add support for the kernel parameter nfs.callback_nr_threads to set
the number of threads that will be assigned to the callback channel.

Add support for the kernel parameter nfs.nfs.max_session_cb_slots
to set the maximum size of the callback channel slot table.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent bb6aeba7

Documentation/kernel-parameters.txt

+12 −0
Original line number Diff line number Diff line
@@ -2420,6 +2420,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
	nfsrootdebug	[NFS] enable nfsroot debugging messages.

			See Documentation/filesystems/nfs/nfsroot.txt.



	nfs.callback_nr_threads=

			[NFSv4] set the total number of threads that the

			NFS client will assign to service NFSv4 callback

			requests.



	nfs.callback_tcpport=

			[NFS] set the TCP port on which the NFSv4 callback

			channel should listen.
@@ -2443,6 +2448,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			of returning the full 64-bit number.

			The default is to return 64-bit inode numbers.



	nfs.max_session_cb_slots=

			[NFSv4.1] Sets the maximum number of session

			slots the client will assign to the callback

			channel. This determines the maximum number of

			callbacks the client will process in parallel for

			a particular server.



	nfs.max_session_slots=

			[NFSv4.1] Sets the maximum number of session slots

			the client will attempt to negotiate with the server.

fs/nfs/callback.c

+4 −1
Original line number Diff line number Diff line
@@ -148,11 +148,14 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, 
static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,

				  struct svc_serv *serv)

{

	const int nrservs = NFS4_NR_CALLBACK_THREADS;

	int nrservs = nfs_callback_nr_threads;

	int ret;



	nfs_callback_bc_serv(minorversion, xprt, serv);



	if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)

		nrservs = NFS4_MIN_NR_CALLBACK_THREADS;



	if (serv->sv_nrthreads-1 == nrservs)

		return 0;

fs/nfs/callback.h

+2 −1
Original line number Diff line number Diff line
@@ -198,8 +198,9 @@ extern void nfs_callback_down(int minorversion, struct net *net); 
#define NFS41_BC_MIN_CALLBACKS 1

#define NFS41_BC_MAX_CALLBACKS 1



#define NFS4_NR_CALLBACK_THREADS 1

#define NFS4_MIN_NR_CALLBACK_THREADS 1



extern unsigned int nfs_callback_set_tcpport;

extern unsigned short nfs_callback_nr_threads;



#endif /* __LINUX_FS_NFS_CALLBACK_H */

fs/nfs/nfs4_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -471,6 +471,7 @@ extern struct nfs_subversion nfs_v4; 
struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *);

extern bool nfs4_disable_idmapping;

extern unsigned short max_session_slots;

extern unsigned short max_session_cb_slots;

extern unsigned short send_implementation_id;

extern bool recover_lost_locks;

fs/nfs/nfs4proc.c

+3 −4
Original line number Diff line number Diff line
@@ -7463,7 +7463,7 @@ static void nfs4_init_channel_attrs(struct nfs41_create_session_args *args, 
	args->bc_attrs.max_resp_sz = max_bc_payload;

	args->bc_attrs.max_resp_sz_cached = 0;

	args->bc_attrs.max_ops = NFS4_MAX_BACK_CHANNEL_OPS;

	args->bc_attrs.max_reqs = NFS41_BC_MAX_CALLBACKS;

	args->bc_attrs.max_reqs = min_t(unsigned short, max_session_cb_slots, 1);



	dprintk("%s: Back Channel : max_rqst_sz=%u max_resp_sz=%u "

		"max_resp_sz_cached=%u max_ops=%u max_reqs=%u\n",
@@ -7510,10 +7510,9 @@ static int nfs4_verify_back_channel_attrs(struct nfs41_create_session_args *args 
		return -EINVAL;

	if (rcvd->max_resp_sz_cached > sent->max_resp_sz_cached)

		return -EINVAL;

	/* These would render the backchannel useless: */

	if (rcvd->max_ops != sent->max_ops)

	if (rcvd->max_ops > sent->max_ops)

		return -EINVAL;

	if (rcvd->max_reqs != sent->max_reqs)

	if (rcvd->max_reqs > sent->max_reqs)

		return -EINVAL;

out:

	return 0;