From: Volker Lendecke <vl@samba.org>
Date: Sat, 2 May 2009 09:31:37 +0000 (+0200)
Subject: Fix bug 6302: Give the VFS a chance to read from 0-byte files
X-Git-Tag: tdb-1.1.5~728
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=386a5d99b32fa1296618f59f9a9072d9faf2c8ac;p=thirdparty%2Fsamba.git

Fix bug 6302: Give the VFS a chance to read from 0-byte files
---

diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c
index d2e1f8be5fa..418c8ba7884 100644
--- a/source3/smbd/reply.c
+++ b/source3/smbd/reply.c
@@ -3358,14 +3358,13 @@ static void send_file_readX(connection_struct *conn, struct smb_request *req,
 		return;
 	}
 
-	if (startpos > sbuf.st_size) {
-		smb_maxcnt = 0;
-	} else if (smb_maxcnt > (sbuf.st_size - startpos)) {
-		smb_maxcnt = (sbuf.st_size - startpos);
-	}
-
-	if (smb_maxcnt == 0) {
-		goto normal_read;
+	if (!S_ISREG(sbuf.st_mode) || (startpos > sbuf.st_size)
+	    || (smb_maxcnt > (sbuf.st_size - startpos))) {
+		/*
+		 * We already know that we would do a short read, so don't
+		 * try the sendfile() path.
+		 */
+		goto nosendfile_read;
 	}
 
 #if defined(WITH_SENDFILE)
@@ -3482,6 +3481,8 @@ normal_read:
 		return;
 	}
 
+nosendfile_read:
+
 	reply_outbuf(req, 12, smb_maxcnt);
 
 	nread = read_file(fsp, smb_buf(req->outbuf), startpos, smb_maxcnt);