Merge tag '5.0-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "A set of cifs/smb3 fixes, 4 for stable, most from Pavel. His patches
  fix an important set of crediting (flow control) problems, and also
  two problems in cifs_writepages, ddressing some large i/o and also
  compounding issues"

* tag '5.0-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number
  CIFS: Fix error paths in writeback code
  CIFS: Move credit processing to mid callbacks for SMB3
  CIFS: Fix credits calculation for cancelled requests
  cifs: Fix potential OOB access of lock element array
  cifs: Limit memory used by lock request calls to a page
  cifs: move large array from stack to heap
  CIFS: Do not hide EINTR after sending network packets
  CIFS: Fix credit computation for compounded requests
  CIFS: Do not set credits to 1 if the server didn't grant anything
  CIFS: Fix adjustment of credits for MTU requests
  cifs: Fix a tiny potential memory leak
  cifs: Fix a debug message

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 */

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

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
@@ -2114,7 +2123,7 @@ 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 +2132,7 @@ 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 +2141,8 @@ 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);
 }
 

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));
 	}
 }
 

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;
 		}

fs/cifs/file.c

@@ -733,7 +733,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
 
 	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;
 
 	/*
@@ -2138,15 +2148,18 @@ static int cifs_writepages(struct address_space *mapping,
 
 		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;
 
 		wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
 						  &found_pages);
 		if (!wdata) {
 			rc = -ENOMEM;
+			done = true;
 			add_credits_and_wake_if(server, credits, 0);
 			break;
 		}
@@ -2175,15 +2188,15 @@ static int cifs_writepages(struct address_space *mapping,
 		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
 					SetPageError(wdata->pages[i]);
 				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 @@ static int cifs_writepages(struct address_space *mapping,
 			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 @@ static int cifs_writepages(struct address_space *mapping,
 		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) {

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;
 

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) {