Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262108AbUJZF2N (ORCPT ); Tue, 26 Oct 2004 01:28:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261917AbUJZFZ3 (ORCPT ); Tue, 26 Oct 2004 01:25:29 -0400 Received: from peabody.ximian.com ([130.57.169.10]:64229 "EHLO peabody.ximian.com") by vger.kernel.org with ESMTP id S262146AbUJZFRo (ORCPT ); Tue, 26 Oct 2004 01:17:44 -0400 Subject: Re: [patch] make dnotify a configure-time option From: Robert Love To: Andrew Morton Cc: ttb@tentacle.dhs.org, linux-kernel@vger.kernel.org In-Reply-To: <20041025214947.63031519.akpm@osdl.org> References: <1098765164.6034.38.camel@localhost> <20041025214947.63031519.akpm@osdl.org> Content-Type: text/plain Date: Tue, 26 Oct 2004 01:18:11 -0400 Message-Id: <1098767891.6034.50.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.0.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6883 Lines: 219 On Mon, 2004-10-25 at 21:49 -0700, Andrew Morton wrote: > It's actually a sysctl and is also present in 2.4. I doubt if it's very > useful but it seems a bit random to be deleting it now. Well, let's not pretend that we care about interfaces outside of syscalls. Removing the sysctl simply results in a return of ENOTDIR from sysctl(2). Nothing should break. But, yah, it is a bit random. OK. How about keeping the sysctl, but only when CONFIG_DNOTIFY=y? Here is a version of the patch that leaves the sysctl in when dnotify is enabled, and removes it otherwise. Is this better? Thanks, Robert Love make dnotify configurable, via CONFIG_DNOTIFY. Documentation/dnotify.txt | 6 ++++++ fs/Kconfig | 11 +++++++++++ fs/Makefile | 13 +++++++------ include/linux/dnotify.h | 46 +++++++++++++++++++++++++++++++++++++++++----- include/linux/fs.h | 8 +++++++- kernel/sysctl.c | 2 ++ 6 files changed, 74 insertions(+), 12 deletions(-) diff -urN linux-2.6.9-mm1/Documentation/dnotify.txt linux/Documentation/dnotify.txt --- linux-2.6.9-mm1/Documentation/dnotify.txt 2004-10-18 17:54:32.000000000 -0400 +++ linux/Documentation/dnotify.txt 2004-10-26 01:03:44.120633208 -0400 @@ -54,6 +54,12 @@ Also, files that are unlinked, will still cause notifications in the last directory that they were linked to. +Configuration +------------- + +Dnotify is controlled via the CONFIG_DNOTIFY configuration option. When +disabled, fcntl(fd, F_NOTIFY, ...) will return -EINVAL. + Example ------- diff -urN linux-2.6.9-mm1/fs/Kconfig linux/fs/Kconfig --- linux-2.6.9-mm1/fs/Kconfig 2004-10-26 00:14:31.924435248 -0400 +++ linux/fs/Kconfig 2004-10-26 01:03:44.122632904 -0400 @@ -440,6 +440,17 @@ depends on XFS_QUOTA || QUOTA default y +config DNOTIFY + bool "Dnotify support" + default y + help + Dnotify is a directory-based per-fd file change notification system + that uses signals to communicate events to user-space. There exist + superior alternatives, but some applications may still rely on + dnotify. + + Because of this, if unsure, say Y. + config AUTOFS_FS tristate "Kernel automounter support" help diff -urN linux-2.6.9-mm1/fs/Makefile linux/fs/Makefile --- linux-2.6.9-mm1/fs/Makefile 2004-10-26 00:14:31.933433880 -0400 +++ linux/fs/Makefile 2004-10-26 01:03:44.123632752 -0400 @@ -5,12 +5,11 @@ # Rewritten to use lists instead of if-statements. # -obj-y := open.o read_write.o file_table.o buffer.o \ - bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \ - namei.o fcntl.o ioctl.o readdir.o select.o fifo.o locks.o \ - dcache.o inode.o attr.o bad_inode.o file.o dnotify.o \ - filesystems.o namespace.o seq_file.o xattr.o libfs.o \ - fs-writeback.o mpage.o direct-io.o aio.o +obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \ + block_dev.o char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \ + ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \ + attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \ + seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \ obj-$(CONFIG_EPOLL) += eventpoll.o obj-$(CONFIG_COMPAT) += compat.o @@ -37,6 +36,8 @@ obj-$(CONFIG_QFMT_V2) += quota_v2.o obj-$(CONFIG_QUOTACTL) += quota.o +obj-$(CONFIG_DNOTIFY) += dnotify.o + obj-$(CONFIG_PROC_FS) += proc/ obj-y += partitions/ obj-$(CONFIG_SYSFS) += sysfs/ diff -urN linux-2.6.9-mm1/include/linux/dnotify.h linux/include/linux/dnotify.h --- linux-2.6.9-mm1/include/linux/dnotify.h 2004-10-18 17:53:06.000000000 -0400 +++ linux/include/linux/dnotify.h 2004-10-26 01:03:44.123632752 -0400 @@ -1,3 +1,5 @@ +#ifndef _LINUX_DNOTIFY_H +#define _LINUX_DNOTIFY_H /* * Directory notification for Linux * @@ -8,20 +10,54 @@ struct dnotify_struct { struct dnotify_struct * dn_next; - unsigned long dn_mask; /* Events to be notified - see linux/fcntl.h */ + unsigned long dn_mask; int dn_fd; struct file * dn_filp; fl_owner_t dn_owner; }; +#ifdef __KERNEL__ + +#include + +#ifdef CONFIG_DNOTIFY + extern void __inode_dir_notify(struct inode *, unsigned long); -extern void dnotify_flush(struct file *filp, fl_owner_t id); +extern void dnotify_flush(struct file *, fl_owner_t); extern int fcntl_dirnotify(int, struct file *, unsigned long); -void dnotify_parent(struct dentry *dentry, unsigned long event); +extern void dnotify_parent(struct dentry *, unsigned long); static inline void inode_dir_notify(struct inode *inode, unsigned long event) { - if ((inode)->i_dnotify_mask & (event)) + if (inode->i_dnotify_mask & (event)) __inode_dir_notify(inode, event); } + +#else + +static inline void __inode_dir_notify(struct inode *inode, unsigned long event) +{ +} + +static inline void dnotify_flush(struct file *filp, fl_owner_t id) +{ +} + +static inline int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg) +{ + return -EINVAL; +} + +static inline void dnotify_parent(struct dentry *dentry, unsigned long event) +{ +} + +static inline void inode_dir_notify(struct inode *inode, unsigned long event) +{ +} + +#endif /* CONFIG_DNOTIFY */ + +#endif /* __KERNEL __ */ + +#endif /* _LINUX_DNOTIFY_H */ diff -urN linux-2.6.9-mm1/include/linux/fs.h linux/include/linux/fs.h --- linux-2.6.9-mm1/include/linux/fs.h 2004-10-26 00:14:32.890288416 -0400 +++ linux/include/linux/fs.h 2004-10-26 01:04:12.726284488 -0400 @@ -61,7 +61,11 @@ }; extern struct inodes_stat_t inodes_stat; -extern int leases_enable, dir_notify_enable, lease_break_time; +extern int leases_enable, lease_break_time; + +#ifdef CONFIG_DNOTIFY +extern int dir_notify_enable; +#endif #define NR_FILE 8192 /* this can well be larger on a larger system */ #define NR_RESERVED_FILES 10 /* reserved for root */ @@ -464,8 +468,10 @@ __u32 i_generation; +#ifdef CONFIG_DNOTIFY unsigned long i_dnotify_mask; /* Directory notify events */ struct dnotify_struct *i_dnotify; /* for directory notifications */ +#endif unsigned long i_state; unsigned long dirtied_when; /* jiffies of first dirtying */ diff -urN linux-2.6.9-mm1/kernel/sysctl.c linux/kernel/sysctl.c --- linux-2.6.9-mm1/kernel/sysctl.c 2004-10-26 00:14:33.274230048 -0400 +++ linux/kernel/sysctl.c 2004-10-26 01:00:28.781329296 -0400 @@ -902,6 +902,7 @@ .mode = 0644, .proc_handler = &proc_dointvec, }, +#ifdef CONFIG_DNOTIFY { .ctl_name = FS_DIR_NOTIFY, .procname = "dir-notify-enable", @@ -910,6 +911,7 @@ .mode = 0644, .proc_handler = &proc_dointvec, }, +#endif { .ctl_name = FS_LEASE_TIME, .procname = "lease-break-time", - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/