1 files changed, 32 insertions, 2 deletions

diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index 75be4b46bc6f..fe453a4b3dc8 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -1943,15 +1943,24 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 	struct tcon_link *tlink;
 	struct cifs_tcon *tcon;
+	__u32 dosattr = 0, origattr = 0;
 	struct TCP_Server_Info *server;
 	struct iattr *attrs = NULL;
-	__u32 dosattr = 0, origattr = 0;
+	bool rehash = false;
 
 	cifs_dbg(FYI, "cifs_unlink, dir=0x%p, dentry=0x%p\n", dir, dentry);
 
 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
 		return -EIO;
 
+	/* Unhash dentry in advance to prevent any concurrent opens */
+	spin_lock(&dentry->d_lock);
+	if (!d_unhashed(dentry)) {
+		__d_drop(dentry);
+		rehash = true;
+	}
+	spin_unlock(&dentry->d_lock);
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -2003,7 +2012,8 @@ psx_del_no_retry:
 			cifs_drop_nlink(inode);
 		}
 	} else if (rc == -ENOENT) {
-		d_drop(dentry);
+		if (simple_positive(dentry))
+			d_delete(dentry);
 	} else if (rc == -EBUSY) {
 		if (server->ops->rename_pending_delete) {
 			rc = server->ops->rename_pending_delete(full_path,
@@ -2056,6 +2066,8 @@ unlink_out:
 	kfree(attrs);
 	free_xid(xid);
 	cifs_put_tlink(tlink);
+	if (rehash)
+		d_rehash(dentry);
 	return rc;
 }
 
@@ -2462,6 +2474,7 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	struct cifs_sb_info *cifs_sb;
 	struct tcon_link *tlink;
 	struct cifs_tcon *tcon;
+	bool rehash = false;
 	unsigned int xid;
 	int rc, tmprc;
 	int retry_count = 0;
@@ -2477,6 +2490,17 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
 		return -EIO;
 
+	/*
+	 * Prevent any concurrent opens on the target by unhashing the dentry.
+	 * VFS already unhashes the target when renaming directories.
+	 */
+	if (d_is_positive(target_dentry) && !d_is_dir(target_dentry)) {
+		if (!d_unhashed(target_dentry)) {
+			d_drop(target_dentry);
+			rehash = true;
+		}
+	}
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -2518,6 +2542,8 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 		}
 	}
 
+	if (!rc)
+		rehash = false;
 	/*
 	 * No-replace is the natural behavior for CIFS, so skip unlink hacks.
 	 */
@@ -2576,12 +2602,16 @@ unlink_target:
 			goto cifs_rename_exit;
 		rc = cifs_do_rename(xid, source_dentry, from_name,
 				    target_dentry, to_name);
+		if (!rc)
+			rehash = false;
 	}
 
 	/* force revalidate to go get info when needed */
 	CIFS_I(source_dir)->time = CIFS_I(target_dir)->time = 0;
 
 cifs_rename_exit:
+	if (rehash)
+		d_rehash(target_dentry);
 	kfree(info_buf_source);
 	free_dentry_path(page2);
 	free_dentry_path(page1);