Merge 5.0-rc4 into char-misc-next

We need the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

16 files changed, 337 insertions, 122 deletions

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 593fb422d0f3..e92a2fee3c57 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -252,6 +252,7 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
 	seq_printf(m, ",ACL");
 #endif
 	seq_putc(m, '\n');
+	seq_printf(m, "CIFSMaxBufSize: %d\n", CIFSMaxBufSize);
 	seq_printf(m, "Active VFS Requests: %d\n", GlobalTotalActiveXid);
 	seq_printf(m, "Servers:");
 
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 26776eddd85d..d1f9c2f3f575 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -150,5 +150,5 @@ extern long cifs_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
 extern const struct export_operations cifs_export_ops;
 #endif /* CONFIG_CIFS_NFSD_EXPORT */
 
-#define CIFS_VERSION   "2.15"
+#define CIFS_VERSION   "2.16"
 #endif				/* _CIFSFS_H */
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 01ded7038b19..94dbdbe5be34 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1438,6 +1438,7 @@ struct mid_q_entry {
 	int mid_state;	/* wish this were enum but can not pass to wait_event */
 	unsigned int mid_flags;
 	__le16 command;		/* smb command code */
+	unsigned int optype;	/* operation type */
 	bool large_buf:1;	/* if valid response, is pointer to large buf */
 	bool multiRsp:1;	/* multiple trans2 responses for one request  */
 	bool multiEnd:1;	/* both received */
@@ -1574,6 +1575,25 @@ static inline void free_dfs_info_array(struct dfs_info3_param *param,
 	kfree(param);
 }
 
+static inline bool is_interrupt_error(int error)
+{
+	switch (error) {
+	case -EINTR:
+	case -ERESTARTSYS:
+	case -ERESTARTNOHAND:
+	case -ERESTARTNOINTR:
+		return true;
+	}
+	return false;
+}
+
+static inline bool is_retryable_error(int error)
+{
+	if (is_interrupt_error(error) || error == -EAGAIN)
+		return true;
+	return false;
+}
+
 #define   MID_FREE 0
 #define   MID_REQUEST_ALLOCATED 1
 #define   MID_REQUEST_SUBMITTED 2
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index b1f49c1c543a..bb54ccf8481c 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -128,24 +128,31 @@ static int __cifs_reconnect_tcon(const struct nls_table *nlsc,
 	int rc;
 	struct dfs_cache_tgt_list tl;
 	struct dfs_cache_tgt_iterator *it = NULL;
-	char tree[MAX_TREE_SIZE + 1];
+	char *tree;
 	const char *tcp_host;
 	size_t tcp_host_len;
 	const char *dfs_host;
 	size_t dfs_host_len;
 
+	tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
+	if (!tree)
+		return -ENOMEM;
+
 	if (tcon->ipc) {
-		snprintf(tree, sizeof(tree), "\\\\%s\\IPC$",
+		snprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$",
 			 tcon->ses->server->hostname);
-		return CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
+		rc = CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
+		goto out;
 	}
 
-	if (!tcon->dfs_path)
-		return CIFSTCon(0, tcon->ses, tcon->treeName, tcon, nlsc);
+	if (!tcon->dfs_path) {
+		rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon, nlsc);
+		goto out;
+	}
 
 	rc = dfs_cache_noreq_find(tcon->dfs_path + 1, NULL, &tl);
 	if (rc)
-		return rc;
+		goto out;
 
 	extract_unc_hostname(tcon->ses->server->hostname, &tcp_host,
 			     &tcp_host_len);
@@ -165,7 +172,7 @@ static int __cifs_reconnect_tcon(const struct nls_table *nlsc,
 			continue;
 		}
 
-		snprintf(tree, sizeof(tree), "\\%s", tgt);
+		snprintf(tree, MAX_TREE_SIZE, "\\%s", tgt);
 
 		rc = CIFSTCon(0, tcon->ses, tree, tcon, nlsc);
 		if (!rc)
@@ -182,6 +189,8 @@ static int __cifs_reconnect_tcon(const struct nls_table *nlsc,
 			rc = -ENOENT;
 	}
 	dfs_cache_free_tgts(&tl);
+out:
+	kfree(tree);
 	return rc;
 }
 #else
@@ -1540,18 +1549,26 @@ cifs_discard_remaining_data(struct TCP_Server_Info *server)
 }
 
 static int
-cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+__cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid,
+		     bool malformed)
 {
 	int length;
-	struct cifs_readdata *rdata = mid->callback_data;
 
 	length = cifs_discard_remaining_data(server);
-	dequeue_mid(mid, rdata->result);
+	dequeue_mid(mid, malformed);
 	mid->resp_buf = server->smallbuf;
 	server->smallbuf = NULL;
 	return length;
 }
 
+static int
+cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+{
+	struct cifs_readdata *rdata = mid->callback_data;
+
+	return  __cifs_readv_discard(server, mid, rdata->result);
+}
+
 int
 cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 {
@@ -1593,12 +1610,23 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 		return -1;
 	}
 
+	/* set up first two iov for signature check and to get credits */
+	rdata->iov[0].iov_base = buf;
+	rdata->iov[0].iov_len = 4;
+	rdata->iov[1].iov_base = buf + 4;
+	rdata->iov[1].iov_len = server->total_read - 4;
+	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
+	cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
+
 	/* Was the SMB read successful? */
 	rdata->result = server->ops->map_error(buf, false);
 	if (rdata->result != 0) {
 		cifs_dbg(FYI, "%s: server returned error %d\n",
 			 __func__, rdata->result);
-		return cifs_readv_discard(server, mid);
+		/* normal error on read response */
+		return __cifs_readv_discard(server, mid, false);
 	}
 
 	/* Is there enough to get to the rest of the READ_RSP header? */
@@ -1642,14 +1670,6 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 		server->total_read += length;
 	}
 
-	/* set up first iov for signature check */
-	rdata->iov[0].iov_base = buf;
-	rdata->iov[0].iov_len = 4;
-	rdata->iov[1].iov_base = buf + 4;
-	rdata->iov[1].iov_len = server->total_read - 4;
-	cifs_dbg(FYI, "0: iov_base=%p iov_len=%u\n",
-		 rdata->iov[0].iov_base, server->total_read);
-
 	/* how much data is in the response? */
 #ifdef CONFIG_CIFS_SMB_DIRECT
 	use_rdma_mr = rdata->mr;
@@ -2114,7 +2134,7 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 
 		for (j = 0; j < nr_pages; j++) {
 			unlock_page(wdata2->pages[j]);
-			if (rc != 0 && rc != -EAGAIN) {
+			if (rc != 0 && !is_retryable_error(rc)) {
 				SetPageError(wdata2->pages[j]);
 				end_page_writeback(wdata2->pages[j]);
 				put_page(wdata2->pages[j]);
@@ -2123,7 +2143,7 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 
 		if (rc) {
 			kref_put(&wdata2->refcount, cifs_writedata_release);
-			if (rc == -EAGAIN)
+			if (is_retryable_error(rc))
 				continue;
 			break;
 		}
@@ -2132,7 +2152,8 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 		i += nr_pages;
 	} while (i < wdata->nr_pages);
 
-	mapping_set_error(inode->i_mapping, rc);
+	if (rc != 0 && !is_retryable_error(rc))
+		mapping_set_error(inode->i_mapping, rc);
 	kref_put(&wdata->refcount, cifs_writedata_release);
 }
 
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index f66529679ca2..8463c940e0e5 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -433,9 +433,10 @@ static void reconn_inval_dfs_target(struct TCP_Server_Info *server,
 	kfree(server->hostname);
 
 	server->hostname = extract_hostname(name);
-	if (!server->hostname) {
-		cifs_dbg(FYI, "%s: failed to extract hostname from target: %d\n",
-			 __func__, -ENOMEM);
+	if (IS_ERR(server->hostname)) {
+		cifs_dbg(FYI,
+			 "%s: failed to extract hostname from target: %ld\n",
+			 __func__, PTR_ERR(server->hostname));
 	}
 }
 
@@ -719,6 +720,21 @@ server_unresponsive(struct TCP_Server_Info *server)
 	return false;
 }
 
+static inline bool
+zero_credits(struct TCP_Server_Info *server)
+{
+	int val;
+
+	spin_lock(&server->req_lock);
+	val = server->credits + server->echo_credits + server->oplock_credits;
+	if (server->in_flight == 0 && val == 0) {
+		spin_unlock(&server->req_lock);
+		return true;
+	}
+	spin_unlock(&server->req_lock);
+	return false;
+}
+
 static int
 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 {
@@ -731,6 +747,12 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 		try_to_freeze();
 
+		/* reconnect if no credits and no requests in flight */
+		if (zero_credits(server)) {
+			cifs_reconnect(server);
+			return -ECONNABORTED;
+		}
+
 		if (server_unresponsive(server))
 			return -ECONNABORTED;
 		if (cifs_rdma_enabled(server) && server->smbd_conn)
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index cd63c4a70875..09b7d0d4f6e4 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -776,6 +776,7 @@ static int get_tgt_list(const struct dfs_cache_entry *ce,
 		it->it_name = kstrndup(t->t_name, strlen(t->t_name),
 				       GFP_KERNEL);
 		if (!it->it_name) {
+			kfree(it);
 			rc = -ENOMEM;
 			goto err_free_it;
 		}
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e3e3a7550205..2c7689f3998d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -733,7 +733,8 @@ reopen_success:
 
 	if (can_flush) {
 		rc = filemap_write_and_wait(inode->i_mapping);
-		mapping_set_error(inode->i_mapping, rc);
+		if (!is_interrupt_error(rc))
+			mapping_set_error(inode->i_mapping, rc);
 
 		if (tcon->unix_ext)
 			rc = cifs_get_inode_info_unix(&inode, full_path,
@@ -1132,14 +1133,18 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
 
 	/*
 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
-	 * and check it for zero before using.
+	 * and check it before using.
 	 */
 	max_buf = tcon->ses->server->maxBuf;
-	if (!max_buf) {
+	if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) {
 		free_xid(xid);
 		return -EINVAL;
 	}
 
+	BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >
+		     PAGE_SIZE);
+	max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr),
+			PAGE_SIZE);
 	max_num = (max_buf - sizeof(struct smb_hdr)) /
 						sizeof(LOCKING_ANDX_RANGE);
 	buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
@@ -1472,12 +1477,16 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 
 	/*
 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
-	 * and check it for zero before using.
+	 * and check it before using.
 	 */
 	max_buf = tcon->ses->server->maxBuf;
-	if (!max_buf)
+	if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE)))
 		return -EINVAL;
 
+	BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >
+		     PAGE_SIZE);
+	max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr),
+			PAGE_SIZE);
 	max_num = (max_buf - sizeof(struct smb_hdr)) /
 						sizeof(LOCKING_ANDX_RANGE);
 	buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
@@ -2110,6 +2119,7 @@ static int cifs_writepages(struct address_space *mapping,
 	pgoff_t end, index;
 	struct cifs_writedata *wdata;
 	int rc = 0;
+	int saved_rc = 0;
 	unsigned int xid;
 
 	/*
@@ -2138,8 +2148,10 @@ retry:
 
 		rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
 						   &wsize, &credits);
-		if (rc)
+		if (rc != 0) {
+			done = true;
 			break;
+		}
 
 		tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
 
@@ -2147,6 +2159,7 @@ retry:
 						  &found_pages);
 		if (!wdata) {
 			rc = -ENOMEM;
+			done = true;
 			add_credits_and_wake_if(server, credits, 0);
 			break;
 		}
@@ -2175,7 +2188,7 @@ retry:
 		if (rc != 0) {
 			add_credits_and_wake_if(server, wdata->credits, 0);
 			for (i = 0; i < nr_pages; ++i) {
-				if (rc == -EAGAIN)
+				if (is_retryable_error(rc))
 					redirty_page_for_writepage(wbc,
 							   wdata->pages[i]);
 				else
@@ -2183,7 +2196,7 @@ retry:
 				end_page_writeback(wdata->pages[i]);
 				put_page(wdata->pages[i]);
 			}
-			if (rc != -EAGAIN)
+			if (!is_retryable_error(rc))
 				mapping_set_error(mapping, rc);
 		}
 		kref_put(&wdata->refcount, cifs_writedata_release);
@@ -2193,6 +2206,15 @@ retry:
 			continue;
 		}
 
+		/* Return immediately if we received a signal during writing */
+		if (is_interrupt_error(rc)) {
+			done = true;
+			break;
+		}
+
+		if (rc != 0 && saved_rc == 0)
+			saved_rc = rc;
+
 		wbc->nr_to_write -= nr_pages;
 		if (wbc->nr_to_write <= 0)
 			done = true;
@@ -2210,6 +2232,9 @@ retry:
 		goto retry;
 	}
 
+	if (saved_rc != 0)
+		rc = saved_rc;
+
 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
 		mapping->writeback_index = index;
 
@@ -2242,8 +2267,8 @@ cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
 	set_page_writeback(page);
 retry_write:
 	rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
-	if (rc == -EAGAIN) {
-		if (wbc->sync_mode == WB_SYNC_ALL)
+	if (is_retryable_error(rc)) {
+		if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN)
 			goto retry_write;
 		redirty_page_for_writepage(wbc, page);
 	} else if (rc != 0) {
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 13fb59aadebc..478003644916 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2257,6 +2257,11 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 	 * the flush returns error?
 	 */
 	rc = filemap_write_and_wait(inode->i_mapping);
+	if (is_interrupt_error(rc)) {
+		rc = -ERESTARTSYS;
+		goto out;
+	}
+
 	mapping_set_error(inode->i_mapping, rc);
 	rc = 0;
 
@@ -2400,6 +2405,11 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 	 * the flush returns error?
 	 */
 	rc = filemap_write_and_wait(inode->i_mapping);
+	if (is_interrupt_error(rc)) {
+		rc = -ERESTARTSYS;
+		goto cifs_setattr_exit;
+	}
+
 	mapping_set_error(inode->i_mapping, rc);
 	rc = 0;
 
diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index 4ed10dd086e6..b204e84b87fb 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -122,12 +122,14 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 
 	/*
 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
-	 * and check it for zero before using.
+	 * and check it before using.
 	 */
 	max_buf = tcon->ses->server->maxBuf;
-	if (!max_buf)
+	if (max_buf < sizeof(struct smb2_lock_element))
 		return -EINVAL;
 
+	BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
+	max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 	max_num = max_buf / sizeof(struct smb2_lock_element);
 	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 	if (!buf)
@@ -264,6 +266,8 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 		return -EINVAL;
 	}
 
+	BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
+	max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 	max_num = max_buf / sizeof(struct smb2_lock_element);
 	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 	if (!buf) {
diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index f14533da3a93..01a76bccdb8d 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -293,6 +293,8 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
 	int rc;
 	struct smb2_file_all_info *smb2_data;
 	__u32 create_options = 0;
+	struct cifs_fid fid;
+	bool no_cached_open = tcon->nohandlecache;
 
 	*adjust_tz = false;
 	*symlink = false;
@@ -301,6 +303,21 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
 			    GFP_KERNEL);
 	if (smb2_data == NULL)
 		return -ENOMEM;
+
+	/* If it is a root and its handle is cached then use it */
+	if (!strlen(full_path) && !no_cached_open) {
+		rc = open_shroot(xid, tcon, &fid);
+		if (rc)
+			goto out;
+		rc = SMB2_query_info(xid, tcon, fid.persistent_fid,
+				     fid.volatile_fid, smb2_data);
+		close_shroot(&tcon->crfid);
+		if (rc)
+			goto out;
+		move_smb2_info_to_cifs(data, smb2_data);
+		goto out;
+	}
+
 	if (backup_cred(cifs_sb))
 		create_options |= CREATE_OPEN_BACKUP_INTENT;
 
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 6a9c47541c53..7b8b58fb4d3f 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -648,6 +648,13 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 	if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
 		return false;
 
+	if (rsp->sync_hdr.CreditRequest) {
+		spin_lock(&server->req_lock);
+		server->credits += le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		spin_unlock(&server->req_lock);
+		wake_up(&server->request_q);
+	}
+
 	if (rsp->StructureSize !=
 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 		if (le16_to_cpu(rsp->StructureSize) == 44)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index cf7eb891804f..153238fc4fa9 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -34,6 +34,7 @@
 #include "cifs_ioctl.h"
 #include "smbdirect.h"
 
+/* Change credits for different ops and return the total number of credits */
 static int
 change_conf(struct TCP_Server_Info *server)
 {
@@ -41,17 +42,15 @@ change_conf(struct TCP_Server_Info *server)
 	server->oplock_credits = server->echo_credits = 0;
 	switch (server->credits) {
 	case 0:
-		return -1;
+		return 0;
 	case 1:
 		server->echoes = false;
 		server->oplocks = false;
-		cifs_dbg(VFS, "disabling echoes and oplocks\n");
 		break;
 	case 2:
 		server->echoes = true;
 		server->oplocks = false;
 		server->echo_credits = 1;
-		cifs_dbg(FYI, "disabling oplocks\n");
 		break;
 	default:
 		server->echoes = true;
@@ -64,14 +63,15 @@ change_conf(struct TCP_Server_Info *server)
 		server->echo_credits = 1;
 	}
 	server->credits -= server->echo_credits + server->oplock_credits;
-	return 0;
+	return server->credits + server->echo_credits + server->oplock_credits;
 }
 
 static void
 smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
 		 const int optype)
 {
-	int *val, rc = 0;
+	int *val, rc = -1;
+
 	spin_lock(&server->req_lock);
 	val = server->ops->get_credits_field(server, optype);
 
@@ -101,8 +101,26 @@ smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
 	}
 	spin_unlock(&server->req_lock);
 	wake_up(&server->request_q);
-	if (rc)
-		cifs_reconnect(server);
+
+	if (server->tcpStatus == CifsNeedReconnect)
+		return;
+
+	switch (rc) {
+	case -1:
+		/* change_conf hasn't been executed */
+		break;
+	case 0:
+		cifs_dbg(VFS, "Possible client or server bug - zero credits\n");
+		break;
+	case 1:
+		cifs_dbg(VFS, "disabling echoes and oplocks\n");
+		break;
+	case 2:
+		cifs_dbg(FYI, "disabling oplocks\n");
+		break;
+	default:
+		cifs_dbg(FYI, "add %u credits total=%d\n", add, rc);
+	}
 }
 
 static void
@@ -136,7 +154,11 @@ smb2_get_credits(struct mid_q_entry *mid)
 {
 	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)mid->resp_buf;
 
-	return le16_to_cpu(shdr->CreditRequest);
+	if (mid->mid_state == MID_RESPONSE_RECEIVED
+	    || mid->mid_state == MID_RESPONSE_MALFORMED)
+		return le16_to_cpu(shdr->CreditRequest);
+
+	return 0;
 }
 
 static int
@@ -165,14 +187,14 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
 
 			scredits = server->credits;
 			/* can deadlock with reopen */
-			if (scredits == 1) {
+			if (scredits <= 8) {
 				*num = SMB2_MAX_BUFFER_SIZE;
 				*credits = 0;
 				break;
 			}
 
-			/* leave one credit for a possible reopen */
-			scredits--;
+			/* leave some credits for reopen and other ops */
+			scredits -= 8;
 			*num = min_t(unsigned int, size,
 				     scredits * SMB2_MAX_BUFFER_SIZE);
 
@@ -3189,11 +3211,23 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 			server->ops->is_status_pending(buf, server, 0))
 		return -1;
 
-	rdata->result = server->ops->map_error(buf, false);
+	/* set up first two iov to get credits */
+	rdata->iov[0].iov_base = buf;
+	rdata->iov[0].iov_len = 4;
+	rdata->iov[1].iov_base = buf + 4;
+	rdata->iov[1].iov_len =
+		min_t(unsigned int, buf_len, server->vals->read_rsp_size) - 4;
+	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
+	cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
+		 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
+
+	rdata->result = server->ops->map_error(buf, true);
 	if (rdata->result != 0) {
 		cifs_dbg(FYI, "%s: server returned error %d\n",
 			 __func__, rdata->result);
-		dequeue_mid(mid, rdata->result);
+		/* normal error on read response */
+		dequeue_mid(mid, false);
 		return 0;
 	}
 
@@ -3266,14 +3300,6 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 		return 0;
 	}
 
-	/* set up first iov for signature check */
-	rdata->iov[0].iov_base = buf;
-	rdata->iov[0].iov_len = 4;
-	rdata->iov[1].iov_base = buf + 4;
-	rdata->iov[1].iov_len = server->vals->read_rsp_size - 4;
-	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
-		 rdata->iov[0].iov_base, server->vals->read_rsp_size);
-
 	length = rdata->copy_into_pages(server, rdata, &iter);
 
 	kfree(bvec);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e57f6aa1d638..2ff209ec4fab 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -162,24 +162,31 @@ static int __smb2_reconnect(const struct nls_table *nlsc,
 	int rc;
 	struct dfs_cache_tgt_list tl;
 	struct dfs_cache_tgt_iterator *it = NULL;
-	char tree[MAX_TREE_SIZE + 1];
+	char *tree;
 	const char *tcp_host;
 	size_t tcp_host_len;
 	const char *dfs_host;
 	size_t dfs_host_len;
 
+	tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
+	if (!tree)
+		return -ENOMEM;
+
 	if (tcon->ipc) {
-		snprintf(tree, sizeof(tree), "\\\\%s\\IPC$",
+		snprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$",
 			 tcon->ses->server->hostname);
-		return SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
+		rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
+		goto out;
 	}
 
-	if (!tcon->dfs_path)
-		return SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
+	if (!tcon->dfs_path) {
+		rc = SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
+		goto out;
+	}
 
 	rc = dfs_cache_noreq_find(tcon->dfs_path + 1, NULL, &tl);
 	if (rc)
-		return rc;
+		goto out;
 
 	extract_unc_hostname(tcon->ses->server->hostname, &tcp_host,
 			     &tcp_host_len);
@@ -199,7 +206,7 @@ static int __smb2_reconnect(const struct nls_table *nlsc,
 			continue;
 		}
 
-		snprintf(tree, sizeof(tree), "\\%s", tgt);
+		snprintf(tree, MAX_TREE_SIZE, "\\%s", tgt);
 
 		rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
 		if (!rc)
@@ -216,6 +223,8 @@ static int __smb2_reconnect(const struct nls_table *nlsc,
 			rc = -ENOENT;
 	}
 	dfs_cache_free_tgts(&tl);
+out:
+	kfree(tree);
 	return rc;
 }
 #else
@@ -2807,6 +2816,7 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon,
 	int resp_buftype = CIFS_NO_BUFFER;
 	struct cifs_ses *ses = tcon->ses;
 	int flags = 0;
+	bool allocated = false;
 
 	cifs_dbg(FYI, "Query Info\n");
 
@@ -2846,14 +2856,21 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon,
 					"Error %d allocating memory for acl\n",
 					rc);
 				*dlen = 0;
+				rc = -ENOMEM;
 				goto qinf_exit;
 			}
+			allocated = true;
 		}
 	}
 
 	rc = smb2_validate_and_copy_iov(le16_to_cpu(rsp->OutputBufferOffset),
 					le32_to_cpu(rsp->OutputBufferLength),
 					&rsp_iov, min_len, *data);
+	if (rc && allocated) {
+		kfree(*data);
+		*data = NULL;
+		*dlen = 0;
+	}
 
 qinf_exit:
 	SMB2_query_info_free(&rqst);
@@ -2907,9 +2924,10 @@ smb2_echo_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->callback_data;
 	struct smb2_echo_rsp *rsp = (struct smb2_echo_rsp *)mid->resp_buf;
-	unsigned int credits_received = 1;
+	unsigned int credits_received = 0;
 
-	if (mid->mid_state == MID_RESPONSE_RECEIVED)
+	if (mid->mid_state == MID_RESPONSE_RECEIVED
+	    || mid->mid_state == MID_RESPONSE_MALFORMED)
 		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
 
 	DeleteMidQEntry(mid);
@@ -3166,7 +3184,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
 	struct TCP_Server_Info *server = tcon->ses->server;
 	struct smb2_sync_hdr *shdr =
 				(struct smb2_sync_hdr *)rdata->iov[0].iov_base;
-	unsigned int credits_received = 1;
+	unsigned int credits_received = 0;
 	struct smb_rqst rqst = { .rq_iov = rdata->iov,
 				 .rq_nvec = 2,
 				 .rq_pages = rdata->pages,
@@ -3205,6 +3223,9 @@ smb2_readv_callback(struct mid_q_entry *mid)
 		task_io_account_read(rdata->got_bytes);
 		cifs_stats_bytes_read(tcon, rdata->got_bytes);
 		break;
+	case MID_RESPONSE_MALFORMED:
+		credits_received = le16_to_cpu(shdr->CreditRequest);
+		/* fall through */
 	default:
 		if (rdata->result != -ENODATA)
 			rdata->result = -EIO;
@@ -3278,12 +3299,14 @@ smb2_async_readv(struct cifs_readdata *rdata)
 	if (rdata->credits) {
 		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
 						SMB2_MAX_BUFFER_SIZE));
-		shdr->CreditRequest = shdr->CreditCharge;
+		shdr->CreditRequest =
+			cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
 		spin_lock(&server->req_lock);
 		server->credits += rdata->credits -
 						le16_to_cpu(shdr->CreditCharge);
 		spin_unlock(&server->req_lock);
 		wake_up(&server->request_q);
+		rdata->credits = le16_to_cpu(shdr->CreditCharge);
 		flags |= CIFS_HAS_CREDITS;
 	}
 
@@ -3388,7 +3411,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
 	struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
 	unsigned int written;
 	struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf;
-	unsigned int credits_received = 1;
+	unsigned int credits_received = 0;
 
 	switch (mid->mid_state) {
 	case MID_RESPONSE_RECEIVED:
@@ -3416,6 +3439,9 @@ smb2_writev_callback(struct mid_q_entry *mid)
 	case MID_RETRY_NEEDED:
 		wdata->result = -EAGAIN;
 		break;
+	case MID_RESPONSE_MALFORMED:
+		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		/* fall through */
 	default:
 		wdata->result = -EIO;
 		break;
@@ -3555,12 +3581,14 @@ smb2_async_writev(struct cifs_writedata *wdata,
 	if (wdata->credits) {
 		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
 						    SMB2_MAX_BUFFER_SIZE));
-		shdr->CreditRequest = shdr->CreditCharge;
+		shdr->CreditRequest =
+			cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
 		spin_lock(&server->req_lock);
 		server->credits += wdata->credits -
 						le16_to_cpu(shdr->CreditCharge);
 		spin_unlock(&server->req_lock);
 		wake_up(&server->request_q);
+		wdata->credits = le16_to_cpu(shdr->CreditCharge);
 		flags |= CIFS_HAS_CREDITS;
 	}
 
diff --git a/fs/cifs/trace.c b/fs/cifs/trace.c
index bd4a546feec1..465483787193 100644
--- a/fs/cifs/trace.c
+++ b/fs/cifs/trace.c
@@ -3,16 +3,6 @@
  *   Copyright (C) 2018, Microsoft Corporation.
  *
  *   Author(s): Steve French <stfrench@microsoft.com>
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
  */
 #define CREATE_TRACE_POINTS
 #include "trace.h"
diff --git a/fs/cifs/trace.h b/fs/cifs/trace.h
index fb049809555f..59be48206932 100644
--- a/fs/cifs/trace.h
+++ b/fs/cifs/trace.h
@@ -3,16 +3,6 @@
  *   Copyright (C) 2018, Microsoft Corporation.
  *
  *   Author(s): Steve French <stfrench@microsoft.com>
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
  */
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM cifs
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 5be7302853b6..53532bd3f50d 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -387,7 +387,7 @@ smbd_done:
 	if (rc < 0 && rc != -EINTR)
 		cifs_dbg(VFS, "Error %d sending data on socket to server\n",
 			 rc);
-	else
+	else if (rc > 0)
 		rc = 0;
 
 	return rc;
@@ -783,8 +783,25 @@ cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 }
 
 static void
-cifs_noop_callback(struct mid_q_entry *mid)
+cifs_compound_callback(struct mid_q_entry *mid)
+{
+	struct TCP_Server_Info *server = mid->server;
+
+	add_credits(server, server->ops->get_credits(mid), mid->optype);
+}
+
+static void
+cifs_compound_last_callback(struct mid_q_entry *mid)
 {
+	cifs_compound_callback(mid);
+	cifs_wake_up_task(mid);
+}
+
+static void
+cifs_cancelled_callback(struct mid_q_entry *mid)
+{
+	cifs_compound_callback(mid);
+	DeleteMidQEntry(mid);
 }
 
 int
@@ -795,7 +812,8 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	int i, j, rc = 0;
 	int timeout, optype;
 	struct mid_q_entry *midQ[MAX_COMPOUND];
-	unsigned int credits = 0;
+	bool cancelled_mid[MAX_COMPOUND] = {false};
+	unsigned int credits[MAX_COMPOUND] = {0};
 	char *buf;
 
 	timeout = flags & CIFS_TIMEOUT_MASK;
@@ -813,13 +831,31 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		return -ENOENT;
 
 	/*
-	 * Ensure that we do not send more than 50 overlapping requests
-	 * to the same server. We may make this configurable later or
-	 * use ses->maxReq.
+	 * Ensure we obtain 1 credit per request in the compound chain.
+	 * It can be optimized further by waiting for all the credits
+	 * at once but this can wait long enough if we don't have enough
+	 * credits due to some heavy operations in progress or the server
+	 * not granting us much, so a fallback to the current approach is
+	 * needed anyway.
 	 */
-	rc = wait_for_free_request(ses->server, timeout, optype);
-	if (rc)
-		return rc;
+	for (i = 0; i < num_rqst; i++) {
+		rc = wait_for_free_request(ses->server, timeout, optype);
+		if (rc) {
+			/*
+			 * We haven't sent an SMB packet to the server yet but
+			 * we already obtained credits for i requests in the
+			 * compound chain - need to return those credits back
+			 * for future use. Note that we need to call add_credits
+			 * multiple times to match the way we obtained credits
+			 * in the first place and to account for in flight
+			 * requests correctly.
+			 */
+			for (j = 0; j < i; j++)
+				add_credits(ses->server, 1, optype);
+			return rc;
+		}
+		credits[i] = 1;
+	}
 
 	/*
 	 * Make sure that we sign in the same order that we send on this socket
@@ -835,18 +871,24 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 			for (j = 0; j < i; j++)
 				cifs_delete_mid(midQ[j]);
 			mutex_unlock(&ses->server->srv_mutex);
+
 			/* Update # of requests on wire to server */
-			add_credits(ses->server, 1, optype);
+			for (j = 0; j < num_rqst; j++)
+				add_credits(ses->server, credits[j], optype);
 			return PTR_ERR(midQ[i]);
 		}
 
 		midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
+		midQ[i]->optype = optype;
 		/*
-		 * We don't invoke the callback compounds unless it is the last
-		 * request.
+		 * Invoke callback for every part of the compound chain
+		 * to calculate credits properly. Wake up this thread only when
+		 * the last element is received.
 		 */
 		if (i < num_rqst - 1)
-			midQ[i]->callback = cifs_noop_callback;
+			midQ[i]->callback = cifs_compound_callback;
+		else
+			midQ[i]->callback = cifs_compound_last_callback;
 	}
 	cifs_in_send_inc(ses->server);
 	rc = smb_send_rqst(ses->server, num_rqst, rqst, flags);
@@ -860,8 +902,20 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	mutex_unlock(&ses->server->srv_mutex);
 
-	if (rc < 0)
+	if (rc < 0) {
+		/* Sending failed for some reason - return credits back */
+		for (i = 0; i < num_rqst; i++)
+			add_credits(ses->server, credits[i], optype);
 		goto out;
+	}
+
+	/*
+	 * At this point the request is passed to the network stack - we assume
+	 * that any credits taken from the server structure on the client have
+	 * been spent and we can't return them back. Once we receive responses
+	 * we will collect credits granted by the server in the mid callbacks
+	 * and add those credits to the server structure.
+	 */
 
 	/*
 	 * Compounding is never used during session establish.
@@ -875,36 +929,34 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	for (i = 0; i < num_rqst; i++) {
 		rc = wait_for_response(ses->server, midQ[i]);
-		if (rc != 0) {
+		if (rc != 0)
+			break;
+	}
+	if (rc != 0) {
+		for (; i < num_rqst; i++) {
 			cifs_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n",
 				 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
 			send_cancel(ses->server, &rqst[i], midQ[i]);
 			spin_lock(&GlobalMid_Lock);
 			if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
 				midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
-				midQ[i]->callback = DeleteMidQEntry;
-				spin_unlock(&GlobalMid_Lock);
-				add_credits(ses->server, 1, optype);
-				return rc;
+				midQ[i]->callback = cifs_cancelled_callback;
+				cancelled_mid[i] = true;
+				credits[i] = 0;
 			}
 			spin_unlock(&GlobalMid_Lock);
 		}
 	}
 
-	for (i = 0; i < num_rqst; i++)
-		if (midQ[i]->resp_buf)
-			credits += ses->server->ops->get_credits(midQ[i]);
-	if (!credits)
-		credits = 1;
-
 	for (i = 0; i < num_rqst; i++) {
 		if (rc < 0)
 			goto out;
 
 		rc = cifs_sync_mid_result(midQ[i], ses->server);
 		if (rc != 0) {
-			add_credits(ses->server, credits, optype);
-			return rc;
+			/* mark this mid as cancelled to not free it below */
+			cancelled_mid[i] = true;
+			goto out;
 		}
 
 		if (!midQ[i]->resp_buf ||
@@ -951,9 +1003,10 @@ out:
 	 * This is prevented above by using a noop callback that will not
 	 * wake this thread except for the very last PDU.
 	 */
-	for (i = 0; i < num_rqst; i++)
-		cifs_delete_mid(midQ[i]);
-	add_credits(ses->server, credits, optype);
+	for (i = 0; i < num_rqst; i++) {
+		if (!cancelled_mid[i])
+			cifs_delete_mid(midQ[i]);
+	}
 
 	return rc;
 }