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: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Aurelien Aptel 2021-04-09 16:31:37 +02:00 committed by Steve French
parent bb9cad1b49
commit b7fd0fa0ea
5 changed files with 33 additions and 33 deletions

View File

@ -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 @@ skip_rdma:
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;
}

View File

@ -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 */

View File

@ -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;
}

View File

@ -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
};
/*

View File

@ -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) {