From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936594AbXFFWbu (ORCPT ); Wed, 6 Jun 2007 18:31:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936290AbXFFWan (ORCPT ); Wed, 6 Jun 2007 18:30:43 -0400 Received: from x35.xmailserver.org ([64.71.152.41]:1333 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936051AbXFFWaj (ORCPT ); Wed, 6 Jun 2007 18:30:39 -0400 X-AuthUser: davidel@xmailserver.org From: Davide Libenzi To: Linux Kernel Mailing List Cc: Linus Torvalds , Andrew Morton , Ulrich Drepper , Ingo Molnar , Eric Dumazet Date: Wed, 06 Jun 2007 15:30:31 -0700 Subject: [patch 4/8] fdmap v2 - add a new O_NONSEQFD flag to sys_open MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Message-ID: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces a new O_NONSEQFD flag for the sys_open() system call. Using such flag, the caller can ask the kernel to allocate the file descriptor inside the non-sequential area. Signed-off-by: Davide Libenzi - Davide Index: linux-2.6.mod/fs/open.c =================================================================== --- linux-2.6.mod.orig/fs/open.c 2007-06-06 12:48:03.000000000 -0700 +++ linux-2.6.mod/fs/open.c 2007-06-06 12:48:37.000000000 -0700 @@ -978,6 +978,23 @@ return FDMAP_NONSEQ_BASE + (rndb & ((1U << FDMAP_RANDOM_BITS) - 1)); } +/** + * allocate_fd - Allocates a new file descriptor + * + * @flags: [in] Flags to control the allocation type and the new descriptor + * characteristics + * + * Returns the newly allocated file descriptor, or a negative value in + * case of error. + */ +int allocate_fd(unsigned long flags) +{ + if (flags & O_NONSEQFD) + return alloc_nonseq_fd(current->files, flags); + else + return get_unused_fd(); +} + /* * Install a file pointer in the fd array. * @@ -1011,7 +1028,7 @@ int fd = PTR_ERR(tmp); if (!IS_ERR(tmp)) { - fd = get_unused_fd(); + fd = allocate_fd((unsigned int) flags); if (fd >= 0) { struct file *f = do_filp_open(dfd, tmp, flags, mode); if (IS_ERR(f)) { Index: linux-2.6.mod/include/asm-generic/fcntl.h =================================================================== --- linux-2.6.mod.orig/include/asm-generic/fcntl.h 2007-06-06 12:38:27.000000000 -0700 +++ linux-2.6.mod/include/asm-generic/fcntl.h 2007-06-06 12:48:37.000000000 -0700 @@ -48,6 +48,9 @@ #ifndef O_NOATIME #define O_NOATIME 01000000 #endif +#ifndef O_NONSEQFD +#define O_NONSEQFD 02000000 +#endif #ifndef O_NDELAY #define O_NDELAY O_NONBLOCK #endif Index: linux-2.6.mod/include/linux/file.h =================================================================== --- linux-2.6.mod.orig/include/linux/file.h 2007-06-06 12:48:28.000000000 -0700 +++ linux-2.6.mod/include/linux/file.h 2007-06-06 12:48:37.000000000 -0700 @@ -85,6 +85,7 @@ extern int __alloc_nonseq_fd(struct files_struct *files, unsigned long flags); extern int alloc_nonseq_fd(struct files_struct *files, unsigned long flags); extern unsigned int gen_nonseqfd_base(void); +extern int allocate_fd(unsigned long flags); /** * nonseq_files_fdmap - Must be called with @files->file_lock held. It forces