Commit b7fd0fa0 authored by Aurelien Aptel's avatar Aurelien Aptel Committed by Steve French
Browse files

cifs: simplify SWN code with dummy funcs instead of ifdefs 



This commit doesn't change the logic of SWN.

Add dummy implementation of SWN functions when SWN is disabled instead
of using ifdef sections.

The dummy functions get optimized out, this leads to clearer code and
compile time type-checking regardless of config options with no
runtime penalty.

Leave the simple ifdefs section as-is.

A single bitfield (bool foo:1) on its own will use up one int. Move
tcon->use_witness out of ifdefs with the other tcon bitfields.

Signed-off-by: default avatarAurelien Aptel <aaptel@suse.com>
Reviewed-by: default avatarSamuel Cabrero <scabrero@suse.de>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent bb9cad1b

fs/cifs/cifs_debug.c

+1 −7
Original line number Diff line number Diff line
@@ -23,9 +23,7 @@ 
#ifdef CONFIG_CIFS_SMB_DIRECT

#include "smbdirect.h"

#endif

#ifdef CONFIG_CIFS_SWN_UPCALL

#include "cifs_swn.h"

#endif



void

cifs_dump_mem(char *label, void *data, int length)
@@ -118,10 +116,8 @@ static void cifs_debug_tcon(struct seq_file *m, struct cifs_tcon *tcon) 
		seq_printf(m, " POSIX Extensions");

	if (tcon->ses->server->ops->dump_share_caps)

		tcon->ses->server->ops->dump_share_caps(m, tcon);

#ifdef CONFIG_CIFS_SWN_UPCALL

	if (tcon->use_witness)

		seq_puts(m, " Witness");

#endif



	if (tcon->need_reconnect)

		seq_puts(m, "\tDISCONNECTED ");
@@ -490,10 +486,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v) 


	spin_unlock(&cifs_tcp_ses_lock);

	seq_putc(m, '\n');



#ifdef CONFIG_CIFS_SWN_UPCALL

	cifs_swn_dump(m);

#endif



	/* BB add code to dump additional info such as TCP session info now */

	return 0;

}

fs/cifs/cifs_swn.h

+27 −0
Original line number Diff line number Diff line
@@ -7,11 +7,13 @@ 


#ifndef _CIFS_SWN_H

#define _CIFS_SWN_H

#include "cifsglob.h"



struct cifs_tcon;

struct sk_buff;

struct genl_info;



#ifdef CONFIG_CIFS_SWN_UPCALL

extern int cifs_swn_register(struct cifs_tcon *tcon);



extern int cifs_swn_unregister(struct cifs_tcon *tcon);
@@ -22,4 +24,29 @@ extern void cifs_swn_dump(struct seq_file *m); 


extern void cifs_swn_check(void);



static inline bool cifs_swn_set_server_dstaddr(struct TCP_Server_Info *server)

{

	if (server->use_swn_dstaddr) {

		server->dstaddr = server->swn_dstaddr;

		return true;

	}

	return false;

}



static inline void cifs_swn_reset_server_dstaddr(struct TCP_Server_Info *server)

{

	server->use_swn_dstaddr = false;

}



#else



static inline int cifs_swn_register(struct cifs_tcon *tcon) { return 0; }

static inline int cifs_swn_unregister(struct cifs_tcon *tcon) { return 0; }

static inline int cifs_swn_notify(struct sk_buff *s, struct genl_info *i) { return 0; }

static inline void cifs_swn_dump(struct seq_file *m) {}

static inline void cifs_swn_check(void) {}

static inline bool cifs_swn_set_server_dstaddr(struct TCP_Server_Info *server) { return false; }

static inline void cifs_swn_reset_server_dstaddr(struct TCP_Server_Info *server) {}



#endif /* CONFIG_CIFS_SWN_UPCALL */

#endif /* _CIFS_SWN_H */

fs/cifs/cifsfs.c

+0 −2
Original line number Diff line number Diff line
@@ -656,10 +656,8 @@ cifs_show_options(struct seq_file *s, struct dentry *root) 
		seq_printf(s, ",multichannel,max_channels=%zu",

			   tcon->ses->chan_max);



#ifdef CONFIG_CIFS_SWN_UPCALL

	if (tcon->use_witness)

		seq_puts(s, ",witness");

#endif



	return 0;

}

fs/cifs/cifsglob.h

+1 −3
Original line number Diff line number Diff line
@@ -1070,6 +1070,7 @@ struct cifs_tcon { 
	bool use_resilient:1; /* use resilient instead of durable handles */

	bool use_persistent:1; /* use persistent instead of durable handles */

	bool no_lease:1;    /* Do not request leases on files or directories */

	bool use_witness:1; /* use witness protocol */

	__le32 capabilities;

	__u32 share_flags;

	__u32 maximal_access;
@@ -1094,9 +1095,6 @@ struct cifs_tcon { 
	int remap:2;

	struct list_head ulist; /* cache update list */

#endif

#ifdef CONFIG_CIFS_SWN_UPCALL

	bool use_witness:1; /* use witness protocol */

#endif

};



/*

fs/cifs/connect.c

+4 −21
Original line number Diff line number Diff line
@@ -62,9 +62,7 @@ 
#include "dfs_cache.h"

#endif

#include "fs_context.h"

#ifdef CONFIG_CIFS_SWN_UPCALL

#include "cifs_swn.h"

#endif



extern mempool_t *cifs_req_poolp;

extern bool disable_legacy_dialects;
@@ -314,12 +312,8 @@ cifs_reconnect(struct TCP_Server_Info *server) 


		mutex_lock(&server->srv_mutex);



#ifdef CONFIG_CIFS_SWN_UPCALL

		if (server->use_swn_dstaddr) {

			server->dstaddr = server->swn_dstaddr;

		} else {

#endif



		if (!cifs_swn_set_server_dstaddr(server)) {

#ifdef CONFIG_CIFS_DFS_UPCALL

		if (cifs_sb && cifs_sb->origin_fullpath)

			/*
@@ -344,9 +338,7 @@ cifs_reconnect(struct TCP_Server_Info *server) 
#endif





#ifdef CONFIG_CIFS_SWN_UPCALL

		}

#endif



		if (cifs_rdma_enabled(server))

			rc = smbd_reconnect(server);
@@ -363,9 +355,7 @@ cifs_reconnect(struct TCP_Server_Info *server) 
			if (server->tcpStatus != CifsExiting)

				server->tcpStatus = CifsNeedNegotiate;

			spin_unlock(&GlobalMid_Lock);

#ifdef CONFIG_CIFS_SWN_UPCALL

			server->use_swn_dstaddr = false;

#endif

			cifs_swn_reset_server_dstaddr(server);

			mutex_unlock(&server->srv_mutex);

		}

	} while (server->tcpStatus == CifsNeedReconnect);
@@ -430,10 +420,8 @@ cifs_echo_request(struct work_struct *work) 
		cifs_dbg(FYI, "Unable to send echo request to server: %s\n",

			 server->hostname);



#ifdef CONFIG_CIFS_SWN_UPCALL

	/* Check witness registrations */

	cifs_swn_check();

#endif



requeue_echo:

	queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
@@ -2009,7 +1997,6 @@ cifs_put_tcon(struct cifs_tcon *tcon) 
		return;

	}



#ifdef CONFIG_CIFS_SWN_UPCALL

	if (tcon->use_witness) {

		int rc;
@@ -2019,7 +2006,6 @@ cifs_put_tcon(struct cifs_tcon *tcon) 
					__func__, rc);

		}

	}

#endif



	list_del_init(&tcon->tcon_list);

	spin_unlock(&cifs_tcp_ses_lock);
@@ -2181,9 +2167,9 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx) 
		}

		tcon->use_resilient = true;

	}

#ifdef CONFIG_CIFS_SWN_UPCALL



	tcon->use_witness = false;

	if (ctx->witness) {

	if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {

		if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {

			if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {

				/*
@@ -2209,7 +2195,6 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx) 
			goto out_fail;

		}

	}

#endif



	/* If the user really knows what they are doing they can override */

	if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
@@ -3877,9 +3862,7 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid) 
	ctx->sectype = master_tcon->ses->sectype;

	ctx->sign = master_tcon->ses->sign;

	ctx->seal = master_tcon->seal;

#ifdef CONFIG_CIFS_SWN_UPCALL

	ctx->witness = master_tcon->use_witness;

#endif



	rc = cifs_set_vol_auth(ctx, master_tcon->ses);

	if (rc) {