Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754957AbYK0PD7 (ORCPT ); Thu, 27 Nov 2008 10:03:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752288AbYK0PDs (ORCPT ); Thu, 27 Nov 2008 10:03:48 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:43777 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740AbYK0PDr (ORCPT ); Thu, 27 Nov 2008 10:03:47 -0500 Date: Thu, 27 Nov 2008 15:03:41 +0000 From: Matthew Garrett To: Randy Dunlap Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, mingo@redhat.com, val.henson@gmail.com, matthew@wil.cx Subject: [PATCH v2 2/2] relatime: Allow making relatime the default behaviour Message-ID: <20081127150341.GB20941@srcf.ucam.org> References: <20081126195457.GA3541@srcf.ucam.org> <20081126195824.GB3541@srcf.ucam.org> <492DD035.5020705@oracle.com> <20081127150126.GA20941@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081127150126.GA20941@srcf.ucam.org> User-Agent: Mutt/1.5.12-2006-07-14 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@codon.org.uk X-SA-Exim-Scanned: No (on vavatch.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6041 Lines: 197 Add support for defaulting to relatime Allow the kernel to enable relatime on all mounts by default. This can be configured at build time or by a kernel parameter or sysctl. Also add a MS_NORELATIME mount option to allow the default to be overridden for specific mount points. Signed-off-by: Matthew Garrett --- Incorporates Randy's suggestion to change default_relatime to relatime_default, along with a couple of typographical fixes diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e0f346d..1738be9 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1847,6 +1847,14 @@ and is between 256 and 4096 characters. It is defined in the file [KNL, SMP] Set scheduler's default relax_domain_level. See Documentation/cpusets.txt. + relatime_default= + [FS] mount all filesystems with relative atime + updates by default. + + relatime_interval= + [FS] relative atime update frequency, in seconds. + (default: 1 day: 86400 seconds) + reserve= [KNL,BUGS] Force the kernel to ignore some iomem area reservetop= [X86-32] diff --git a/fs/Kconfig b/fs/Kconfig index 522469a..fcd3d48 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -1546,6 +1546,29 @@ config 9P_FS endif # NETWORK_FILESYSTEMS +config DEFAULT_RELATIME + bool "Mount all filesystems with relatime by default" + default y + help + If you say Y here, all your filesystems will be mounted + with the "relatime" mount option. This eliminates many atime + ('file last accessed' timestamp) updates (which otherwise + is performed on every file access and generates a write + IO to the inode) and thus speeds up IO. Atime is still updated, + but only once per day. + + The mtime ('file last modified') and ctime ('file created') + timestamp are unaffected by this change. + + Use the "norelatime" kernel boot option to turn off this + feature. + +config DEFAULT_RELATIME_VAL + int + default "1" if DEFAULT_RELATIME + default "0" + + if BLOCK menu "Partition Types" diff --git a/fs/inode.c b/fs/inode.c index 348fa16..51e9ae1 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1185,6 +1185,17 @@ EXPORT_SYMBOL(bmap); int relatime_interval __read_mostly = 24*60*60; /* + * Allow overriding the default relatime value on the kernel command line + */ +static int __init set_relatime_interval(char *str) +{ + get_option(&str, &relatime_interval); + + return 1; +} +__setup("relatime_interval=", set_relatime_interval); + +/* * With relative atime, only update atime if the * previous atime is earlier than either the ctime or * mtime. diff --git a/fs/namespace.c b/fs/namespace.c index 65b3dc8..b7b72c2 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1883,6 +1883,24 @@ int copy_mount_options(const void __user * data, unsigned long *where) } /* + * Allow users to disable (or enable) atime updates via a .config + * option or via the boot line, or via /proc/sys/fs/relatime_default: + */ +int relatime_default __read_mostly = CONFIG_DEFAULT_RELATIME_VAL; + +static int __init set_relatime_default(char *str) +{ + get_option(&str, &relatime_default); + + printk(KERN_INFO "Mount all filesystems with " + "default relative atime updates: %s.\n", + relatime_default ? "enabled" : "disabled"); + + return 1; +} +__setup("relatime_default=", set_relatime_default); + +/* * Flags is a 32-bit value that allows up to 31 non-fs dependent flags to * be given to the mount() call (ie: read-only, no-dev, no-suid etc). * @@ -1930,6 +1948,11 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, mnt_flags |= MNT_NODIRATIME; if (flags & MS_RELATIME) mnt_flags |= MNT_RELATIME; + else if (relatime_default && + !(flags & (MS_NOATIME | MS_NODIRATIME | MS_NORELATIME))) { + mnt_flags |= MNT_RELATIME; + flags |= MS_RELATIME; + } if (flags & MS_RDONLY) mnt_flags |= MNT_READONLY; diff --git a/include/linux/fs.h b/include/linux/fs.h index 0dcdd94..0dfdce2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -135,6 +135,7 @@ extern int dir_notify_enable; #define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */ #define MS_KERNMOUNT (1<<22) /* this is a kern_mount call */ #define MS_I_VERSION (1<<23) /* Update inode I_version field */ +#define MS_NORELATIME (1<<24) /* Disable relatime even if the default */ #define MS_ACTIVE (1<<30) #define MS_NOUSER (1<<31) diff --git a/include/linux/mount.h b/include/linux/mount.h index cab2a85..2595882 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -112,4 +112,7 @@ extern void mark_mounts_for_expiry(struct list_head *mounts); extern spinlock_t vfsmount_lock; extern dev_t name_to_dev_t(char *name); +extern int relatime_default; +extern int relatime_interval; + #endif /* _LINUX_MOUNT_H */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 9d048fa..b570827 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -1334,6 +1335,22 @@ static struct ctl_table fs_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "relatime_default", + .data = &relatime_default, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "relatime_interval", + .data = &relatime_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE) { .ctl_name = CTL_UNNUMBERED, -- Matthew Garrett | mjg59@srcf.ucam.org -- 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/