diff --git a/fs/smb/client/cifs_fs_sb.h b/fs/smb/client/cifs_fs_sb.h
index 65175919228014001a7b5c0b0acc4df8c72ed8b2..5e8d163cb5f801eaa25a14e6745ea86311c5008e 100644
--- a/fs/smb/client/cifs_fs_sb.h
+++ b/fs/smb/client/cifs_fs_sb.h
@@ -49,6 +49,7 @@
 
 struct cifs_sb_info {
 	struct rb_root tlink_tree;
+	struct list_head tcon_sb_link;
 	spinlock_t tlink_tree_lock;
 	struct tcon_link *master_tlink;
 	struct nls_table *local_nls;
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 6992e1ec02e4169160e09bb3579b9581ddaab057..62c37cf3032660eb5ed1487b856f92113d92fbe6 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1284,7 +1284,8 @@ struct cifs_tcon {
 #endif
 	struct list_head pending_opens;	/* list of incomplete opens */
 	struct cached_fids *cfids;
-	/* BB add field for back pointer to sb struct(s)? */
+	struct list_head cifs_sb_list;
+	spinlock_t sb_list_lock;
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	struct delayed_work dfs_cache_work;
 #endif
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 8f381bd97142a95c2f4d0c492248ed7bd99bd62a..f7f619b13de1961a217920ed1814c58a0032ef88 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -3354,6 +3354,7 @@ int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
 	struct smb3_fs_context *ctx = cifs_sb->ctx;
 
 	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
+	INIT_LIST_HEAD(&cifs_sb->tcon_sb_link);
 
 	spin_lock_init(&cifs_sb->tlink_tree_lock);
 	cifs_sb->tlink_tree = RB_ROOT;
@@ -3591,6 +3592,10 @@ static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 	tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
 	spin_unlock(&cifs_sb->tlink_tree_lock);
 
+	spin_lock(&tcon->sb_list_lock);
+	list_add(&cifs_sb->tcon_sb_link, &tcon->cifs_sb_list);
+	spin_unlock(&tcon->sb_list_lock);
+
 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
 				TLINK_IDLE_EXPIRE);
 	return 0;
@@ -3933,9 +3938,19 @@ cifs_umount(struct cifs_sb_info *cifs_sb)
 	struct rb_root *root = &cifs_sb->tlink_tree;
 	struct rb_node *node;
 	struct tcon_link *tlink;
+	struct cifs_tcon *tcon = NULL;
 
 	cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
 
+	if (cifs_sb->master_tlink) {
+		tcon = cifs_sb->master_tlink->tl_tcon;
+		if (tcon) {
+			spin_lock(&tcon->sb_list_lock);
+			list_del_init(&cifs_sb->tcon_sb_link);
+			spin_unlock(&tcon->sb_list_lock);
+		}
+	}
+
 	spin_lock(&cifs_sb->tlink_tree_lock);
 	while ((node = rb_first(root))) {
 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index b3fb1db26eb3413a00a36e81cd7e39e381d90b0e..f5750fc6d7218a1f8be49e13e1f00307fd1a93ae 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -1245,6 +1245,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 	case Opt_rsize:
 		ctx->rsize = result.uint_32;
 		ctx->got_rsize = true;
+		ctx->vol_rsize = ctx->rsize;
 		break;
 	case Opt_wsize:
 		ctx->wsize = result.uint_32;
@@ -1260,6 +1261,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 					 ctx->wsize, PAGE_SIZE);
 			}
 		}
+		ctx->vol_wsize = ctx->wsize;
 		break;
 	case Opt_acregmax:
 		if (result.uint_32 > CIFS_MAX_ACTIMEO / HZ) {
diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h
index bbd2063ab838d34197021faceec72bf1043f369f..d0a2043ea44682fdcc46ccaf01141fcc8af674c3 100644
--- a/fs/smb/client/fs_context.h
+++ b/fs/smb/client/fs_context.h
@@ -253,6 +253,9 @@ struct smb3_fs_context {
 	bool use_client_guid:1;
 	/* reuse existing guid for multichannel */
 	u8 client_guid[SMB2_CLIENT_GUID_SIZE];
+	/* User-specified original r/wsize value */
+	unsigned int vol_rsize;
+	unsigned int vol_wsize;
 	unsigned int bsize;
 	unsigned int rasize;
 	unsigned int rsize;
diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c
index 65d4b72b4d51a9ef8b0bd6d52ac948f8bbf272ff..b0381c7dd15b2e0908466e1648575277e192b945 100644
--- a/fs/smb/client/misc.c
+++ b/fs/smb/client/misc.c
@@ -136,8 +136,10 @@ tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace)
 	spin_lock_init(&ret_buf->tc_lock);
 	INIT_LIST_HEAD(&ret_buf->openFileList);
 	INIT_LIST_HEAD(&ret_buf->tcon_list);
+	INIT_LIST_HEAD(&ret_buf->cifs_sb_list);
 	spin_lock_init(&ret_buf->open_file_lock);
 	spin_lock_init(&ret_buf->stat_lock);
+	spin_lock_init(&ret_buf->sb_list_lock);
 	atomic_set(&ret_buf->num_local_opens, 0);
 	atomic_set(&ret_buf->num_remote_opens, 0);
 	ret_buf->stats_from_time = ktime_get_real_seconds();
diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c
index bc1bac36c1b291f2f709cf5dc5944f20148bcaa0..740f9e4b43743fbe3251dd964fcfdf498fcdeef0 100644
--- a/fs/smb/client/smb1ops.c
+++ b/fs/smb/client/smb1ops.c
@@ -444,8 +444,8 @@ cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	unsigned int wsize;
 
 	/* start with specified wsize, or default */
-	if (ctx->wsize)
-		wsize = ctx->wsize;
+	if (ctx->got_wsize)
+		wsize = ctx->vol_wsize;
 	else if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
 		wsize = CIFS_DEFAULT_IOSIZE;
 	else
@@ -497,7 +497,7 @@ cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	else
 		defsize = server->maxBuf - sizeof(READ_RSP);
 
-	rsize = ctx->rsize ? ctx->rsize : defsize;
+	rsize = ctx->got_rsize ? ctx->vol_rsize : defsize;
 
 	/*
 	 * no CAP_LARGE_READ_X? Then MS-CIFS states that we must limit this to
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index b809a616728f27c796197d332709832d9d6f1858..91dbf48de9d03f8b3a49c417b88d28504b7b8b6c 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -434,6 +434,17 @@ smb2_negotiate(const unsigned int xid,
 	return rc;
 }
 
+static inline unsigned int
+prevent_zero_iosize(unsigned int size, const char *type)
+{
+	if (size == 0) {
+		cifs_dbg(VFS, "SMB: Zero %ssize calculated, using minimum value %u\n",
+			 type, CIFS_MIN_DEFAULT_IOSIZE);
+		return CIFS_MIN_DEFAULT_IOSIZE;
+	}
+	return size;
+}
+
 static unsigned int
 smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 {
@@ -441,12 +452,12 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	unsigned int wsize;
 
 	/* start with specified wsize, or default */
-	wsize = ctx->wsize ? ctx->wsize : CIFS_DEFAULT_IOSIZE;
+	wsize = ctx->got_wsize ? ctx->vol_wsize : CIFS_DEFAULT_IOSIZE;
 	wsize = min_t(unsigned int, wsize, server->max_write);
 	if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
 		wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);
 
-	return wsize;
+	return prevent_zero_iosize(wsize, "w");
 }
 
 static unsigned int
@@ -456,7 +467,7 @@ smb3_negotiate_wsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	unsigned int wsize;
 
 	/* start with specified wsize, or default */
-	wsize = ctx->wsize ? ctx->wsize : SMB3_DEFAULT_IOSIZE;
+	wsize = ctx->got_wsize ? ctx->vol_wsize : SMB3_DEFAULT_IOSIZE;
 	wsize = min_t(unsigned int, wsize, server->max_write);
 #ifdef CONFIG_CIFS_SMB_DIRECT
 	if (server->rdma) {
@@ -478,7 +489,7 @@ smb3_negotiate_wsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
 		wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);
 
-	return wsize;
+	return prevent_zero_iosize(wsize, "w");
 }
 
 static unsigned int
@@ -488,13 +499,13 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	unsigned int rsize;
 
 	/* start with specified rsize, or default */
-	rsize = ctx->rsize ? ctx->rsize : CIFS_DEFAULT_IOSIZE;
+	rsize = ctx->got_rsize ? ctx->vol_rsize : CIFS_DEFAULT_IOSIZE;
 	rsize = min_t(unsigned int, rsize, server->max_read);
 
 	if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
 		rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);
 
-	return rsize;
+	return prevent_zero_iosize(rsize, "r");
 }
 
 static unsigned int
@@ -504,7 +515,7 @@ smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	unsigned int rsize;
 
 	/* start with specified rsize, or default */
-	rsize = ctx->rsize ? ctx->rsize : SMB3_DEFAULT_IOSIZE;
+	rsize = ctx->got_rsize ? ctx->vol_rsize : SMB3_DEFAULT_IOSIZE;
 	rsize = min_t(unsigned int, rsize, server->max_read);
 #ifdef CONFIG_CIFS_SMB_DIRECT
 	if (server->rdma) {
@@ -527,7 +538,7 @@ smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
 		rsize = min_t(unsigned int, rsize, SMB2_MAX_BUFFER_SIZE);
 
-	return rsize;
+	return prevent_zero_iosize(rsize, "r");
 }
 
 /*
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 24b1738a35a155080577d269b7ecb8e7a2293f5e..0e84197916ac905303019193023f17c27d783d36 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -40,6 +40,7 @@
 #include "dfs_cache.h"
 #endif
 #include "cached_dir.h"
+#include "fs_context.h"
 
 /*
  *  The following table defines the expected "StructureSize" of SMB2 requests
@@ -4105,6 +4106,24 @@ smb2_echo_callback(struct mid_q_entry *mid)
 	add_credits(server, &credits, CIFS_ECHO_OP);
 }
 
+static void cifs_renegotiate_iosize(struct TCP_Server_Info *server,
+				    struct cifs_tcon *tcon)
+{
+	struct cifs_sb_info *cifs_sb;
+
+	if (server == NULL || tcon == NULL)
+		return;
+
+	spin_lock(&tcon->sb_list_lock);
+	list_for_each_entry(cifs_sb, &tcon->cifs_sb_list, tcon_sb_link) {
+		cifs_sb->ctx->rsize =
+			server->ops->negotiate_rsize(tcon, cifs_sb->ctx);
+		cifs_sb->ctx->wsize =
+			server->ops->negotiate_wsize(tcon, cifs_sb->ctx);
+	}
+	spin_unlock(&tcon->sb_list_lock);
+}
+
 void smb2_reconnect_server(struct work_struct *work)
 {
 	struct TCP_Server_Info *server = container_of(work,
@@ -4190,9 +4209,10 @@ void smb2_reconnect_server(struct work_struct *work)
 
 	list_for_each_entry_safe(tcon, tcon2, &tmp_list, rlist) {
 		rc = smb2_reconnect(SMB2_INTERNAL_CMD, tcon, server, true);
-		if (!rc)
+		if (!rc) {
+			cifs_renegotiate_iosize(server, tcon);
 			cifs_reopen_persistent_handles(tcon);
-		else
+		} else
 			resched = true;
 		list_del_init(&tcon->rlist);
 		if (tcon->ipc)
diff --git a/fs/smb/common/smb2pdu.h b/fs/smb/common/smb2pdu.h
index c3ee42188d252ecb851e3c9fa64a7ba34d4f5278..1af827ae757e0d9d0e384306d0abb89925adee46 100644
--- a/fs/smb/common/smb2pdu.h
+++ b/fs/smb/common/smb2pdu.h
@@ -95,6 +95,9 @@
  */
 #define SMB3_DEFAULT_IOSIZE (4 * 1024 * 1024)
 
+/* According to MS-SMB2 specification The minimum recommended value is 65536.*/
+#define CIFS_MIN_DEFAULT_IOSIZE (65536)
+
 /*
  * SMB2 Header Definition
  *