cifs: simplify handling of cifs_sb/ctx->local_nls

Only load/unload local_nls from cifs_sb and just make the ctx
contain a pointer to cifs_sb->ctx.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsproto.h

@@ -598,9 +598,7 @@ extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
 				unsigned int *len, unsigned int *offset);
 struct cifs_chan *
 cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server);
-int cifs_try_adding_channels(struct cifs_ses *ses);
-int cifs_ses_add_channel(struct cifs_ses *ses,
-				struct cifs_server_iface *iface);
+int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses);
 bool is_server_using_iface(struct TCP_Server_Info *server,
 			   struct cifs_server_iface *iface);
 bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface);

fs/cifs/connect.c

@@ -2717,7 +2717,19 @@ int cifs_setup_cifs_sb(struct smb3_fs_context *ctx,
 	cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
 		 cifs_sb->ctx->file_mode, cifs_sb->ctx->dir_mode);
 
-	cifs_sb->local_nls = ctx->local_nls;
+	/* this is needed for ASCII cp to Unicode converts */
+	if (ctx->iocharset == NULL) {
+		/* load_nls_default cannot return null */
+		cifs_sb->local_nls = load_nls_default();
+	} else {
+		cifs_sb->local_nls = load_nls(ctx->iocharset);
+		if (cifs_sb->local_nls == NULL) {
+			cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
+				 ctx->iocharset);
+			return -ELIBACC;
+		}
+	}
+	ctx->local_nls = cifs_sb->local_nls;
 
 	if (ctx->nodfs)
 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_DFS;
@@ -3187,19 +3199,6 @@ cifs_setup_volume_info(struct smb3_fs_context *ctx)
 		return -EINVAL;
 	}
 
-	/* this is needed for ASCII cp to Unicode converts */
-	if (ctx->iocharset == NULL) {
-		/* load_nls_default cannot return null */
-		ctx->local_nls = load_nls_default();
-	} else {
-		ctx->local_nls = load_nls(ctx->iocharset);
-		if (ctx->local_nls == NULL) {
-			cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
-				 ctx->iocharset);
-			return -ELIBACC;
-		}
-	}
-
 	return rc;
 }
 
@@ -3521,7 +3520,7 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 
 out:
 	free_xid(xid);
-	cifs_try_adding_channels(ses);
+	cifs_try_adding_channels(cifs_sb, ses);
 	return mount_setup_tlink(cifs_sb, ses, tcon);
 
 error:

fs/cifs/fs_context.c

@@ -304,7 +304,6 @@ smb3_fs_context_dup(struct smb3_fs_context *new_ctx, struct smb3_fs_context *ctx
 	memcpy(new_ctx, ctx, sizeof(*ctx));
 	new_ctx->prepath = NULL;
 	new_ctx->mount_options = NULL;
-	new_ctx->local_nls = NULL;
 	new_ctx->nodename = NULL;
 	new_ctx->username = NULL;
 	new_ctx->password = NULL;
@@ -1350,9 +1349,6 @@ smb3_cleanup_fs_context_contents(struct smb3_fs_context *ctx)
 	ctx->iocharset = NULL;
 	kfree(ctx->prepath);
 	ctx->prepath = NULL;
-
-	unload_nls(ctx->local_nls);
-	ctx->local_nls = NULL;
 }
 
 void

fs/cifs/fs_context.h

@@ -237,7 +237,7 @@ struct smb3_fs_context {
 	char *prepath;
 	struct sockaddr_storage dstaddr; /* destination address */
 	struct sockaddr_storage srcaddr; /* allow binding to a local IP */
-	struct nls_table *local_nls;
+	struct nls_table *local_nls; /* This is a copy of the pointer in cifs_sb */
 	unsigned int echo_interval; /* echo interval in secs */
 	__u64 snapshot_time; /* needed for timewarp tokens */
 	__u32 handle_timeout; /* persistent and durable handle timeout in ms */

fs/cifs/sess.c

@@ -34,6 +34,10 @@
 #include "smb2proto.h"
 #include "fs_context.h"
 
+static int
+cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
+		     struct cifs_server_iface *iface);
+
 bool
 is_server_using_iface(struct TCP_Server_Info *server,
 		      struct cifs_server_iface *iface)
@@ -71,7 +75,7 @@ bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface)
 }
 
 /* returns number of channels added */
-int cifs_try_adding_channels(struct cifs_ses *ses)
+int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses)
 {
 	int old_chan_count = ses->chan_count;
 	int left = ses->chan_max - ses->chan_count;
@@ -134,7 +138,7 @@ int cifs_try_adding_channels(struct cifs_ses *ses)
 			continue;
 		}
 
-		rc = cifs_ses_add_channel(ses, iface);
+		rc = cifs_ses_add_channel(cifs_sb, ses, iface);
 		if (rc) {
 			cifs_dbg(FYI, "failed to open extra channel on iface#%d rc=%d\n",
 				 i, rc);
@@ -167,8 +171,9 @@ cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server)
 	return NULL;
 }
 
-int
-cifs_ses_add_channel(struct cifs_ses *ses, struct cifs_server_iface *iface)
+static int
+cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
+		     struct cifs_server_iface *iface)
 {
 	struct cifs_chan *chan;
 	struct smb3_fs_context ctx = {NULL};
@@ -229,13 +234,8 @@ cifs_ses_add_channel(struct cifs_ses *ses, struct cifs_server_iface *iface)
 	/*
 	 * This will be used for encoding/decoding user/domain/pw
 	 * during sess setup auth.
-	 *
-	 * XXX: We use the default for simplicity but the proper way
-	 * would be to use the one that ses used, which is not
-	 * stored. This might break when dealing with non-ascii
-	 * strings.
 	 */
-	ctx.local_nls = load_nls_default();
+	ctx.local_nls = cifs_sb->local_nls;
 
 	/* Use RDMA if possible */
 	ctx.rdma = iface->rdma_capable;
@@ -275,7 +275,7 @@ cifs_ses_add_channel(struct cifs_ses *ses, struct cifs_server_iface *iface)
 	if (rc)
 		goto out;
 
-	rc = cifs_setup_session(xid, ses, ctx.local_nls);
+	rc = cifs_setup_session(xid, ses, cifs_sb->local_nls);
 	if (rc)
 		goto out;
 
@@ -298,7 +298,6 @@ cifs_ses_add_channel(struct cifs_ses *ses, struct cifs_server_iface *iface)
 
 	if (rc && chan->server)
 		cifs_put_tcp_session(chan->server, 0);
-	unload_nls(ctx.local_nls);
 
 	return rc;
 }