From: Hajime Taira Date: Thu, 13 May 2010 11:23:49 +0000 (+0200) Subject: fsfreeze: new command X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f0bef3ca0fed141eff28f972c03c3a10ae01fcaf;p=util-linux fsfreeze: new command [kzak@redhat.com: - cleanup - add long options - add note about DM to the man page - use err.h and nls.h] Signed-off-by: Hajime Taira Signed-off-by: Karel Zak --- diff --git a/include/blkdev.h b/include/blkdev.h index 34e4e924..0eea01cd 100644 --- a/include/blkdev.h +++ b/include/blkdev.h @@ -45,6 +45,11 @@ #define BLKPBSZGET _IO(0x12,123) #endif +#ifndef FIFREEZE +#define FIFREEZE _IOWR('X', 119, int) /* Freeze */ +#define FITHAW _IOWR('X', 120, int) /* Thaw */ +#endif + #ifndef HDIO_GETGEO # ifdef __linux__ # define HDIO_GETGEO 0x0301 diff --git a/sys-utils/.gitignore b/sys-utils/.gitignore index 7985d7a5..f82d1072 100644 --- a/sys-utils/.gitignore +++ b/sys-utils/.gitignore @@ -4,6 +4,7 @@ cytune dmesg fallocate flock +fsfreeze i386.8 ia64.8 ipcmk diff --git a/sys-utils/Makefile.am b/sys-utils/Makefile.am index 76828cc1..957fd6e8 100644 --- a/sys-utils/Makefile.am +++ b/sys-utils/Makefile.am @@ -10,12 +10,12 @@ dist_man_MANS = flock.1 ipcrm.1 ipcs.1 ipcmk.1 renice.1 setsid.1 \ if LINUX bin_PROGRAMS += dmesg -sbin_PROGRAMS += ctrlaltdel +sbin_PROGRAMS += ctrlaltdel fsfreeze usrbin_exec_PROGRAMS += cytune setarch lscpu usrsbin_exec_PROGRAMS += ldattach tunelp rtcwake dist_man_MANS += dmesg.1 ctrlaltdel.8 cytune.8 setarch.8 \ - ldattach.8 lscpu.1 tunelp.8 rtcwake.8 + ldattach.8 lscpu.1 tunelp.8 rtcwake.8 fsfreeze.8 endif cytune_SOURCES = cytune.c cyclades.h diff --git a/sys-utils/fsfreeze.8 b/sys-utils/fsfreeze.8 new file mode 100644 index 00000000..4408bddd --- /dev/null +++ b/sys-utils/fsfreeze.8 @@ -0,0 +1,75 @@ +.\" -*- nroff -*- +.TH FSFREEZE 8 "May 2010" +.SH NAME +fsfreeze \- suspend access to an filesystem (Linux Ext3/4, ReiserFS, JFS, XFS). +.SH SYNOPSIS +.B fsfreeze +.RB \-f +.I mountpoint + +.B fsfreeze +.RB \-u +.I mountpoint + +.SH DESCRIPTION +.B fsfreeze +suspends and resumes access to an filesystem +.PP +.B fsfreeze +halts new access to the filesystem and creates a stable image on disk. +.B fsfreeze +is intended to be used with hardware RAID devices that support the creation +of snapshots. +.PP +.B fsfreeze +is unncessary for +.B device-mapper +devices. The device-mapper (and LVM) +automatically freezes filesystem on the device when a snapshot creation is requested. +For more details see the +.BR dmsetup (8) +man page. +.PP +The +.I mount-point +argument is the pathname of the directory where the filesystem +is mounted. +The filesystem must be mounted to be frozen (see +.BR mount (8)). +.SH OPTIONS +.IP "\fB\-h, \-\-help\fP" +Print help and exit. +.IP "\fB\-f, \-\-freeze\fP" +This option requests the specified a filesystem to be frozen from new +modifications. When this is selected, all ongoing transactions in the +filesystem are allowed to complete, new write system calls are halted, other +calls which modify the filesystem are halted, and all dirty data, metadata, and +log information are written to disk. Any process attempting to write to the +frozen filesystem will block waiting for the filesystem to be unfrozen. + +Note that even after freezing, the on-disk filesystem can contain +information on files that are still in the process of unlinking. +These files will not be unlinked until the filesystem is unfrozen +or a clean mount of the snapshot is complete. +.IP "\fB\-u, \-\-unfreeze\fP +This option is used to un-freeze the filesystem and allow operations to +continue. Any filesystem modifications that were blocked by the freeze are +unblocked and allowed to complete. +.SH AUTHOR +.PP +Written by Hajime Taira. +.SH NOTES +.PP +This man page based on xfs_freeze. +One of +.B \-f +or +.B \-u +must be supplied to +.BR fsfreeze . +.SH SEE ALSO +.BR mount (8) +.SH AVAILABILITY +The fsfreeze command is part of the util-linux-ng package and is available from +ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/. + diff --git a/sys-utils/fsfreeze.c b/sys-utils/fsfreeze.c new file mode 100644 index 00000000..4ca6e5e2 --- /dev/null +++ b/sys-utils/fsfreeze.c @@ -0,0 +1,132 @@ +/* + * fsfreeze.c -- Filesystem freeze/unfreeze IO for Linux + * + * Copyright (C) 2010 Hajime Taira + * Masatake Yamato + * + * This program is free software. You can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation: either version 1 or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "blkdev.h" +#include "nls.h" +#include "c.h" + +static int freeze_f(int fd) +{ + return ioctl(fd, FIFREEZE, 0); +} + +static int unfreeze_f(int fd) +{ + return ioctl(fd, FITHAW, 0); +} + +static void __attribute__((__noreturn__)) usage(FILE *out) +{ + fprintf(out, _("Usage: %s [options] \n\nOptions:\n"), + program_invocation_short_name); + + fprintf(out, _( + " -h, --help this help\n" + " -f, --freeze freeze the filesystem\n" + " -u, --unfreeze unfreeze the filesystem\n")); + + fprintf(out, _("\nFor more information see fsfreeze(8).\n")); + + exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); +} + +int main(int argc, char **argv) +{ + int fd = -1, c; + int freeze = -1, rc = EXIT_FAILURE; + char *path; + struct stat sb; + + struct option longopts[] = { + { "help", 0, 0, 'h' }, + { "freeze", 0, 0, 'f' }, + { "unfreeze", 0, 0, 'u' }, + { NULL, 0, 0, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + + while ((c = getopt_long(argc, argv, "hfu", longopts, NULL)) != -1) { + switch(c) { + case 'h': + usage(stdout); + break; + case 'f': + freeze = TRUE; + break; + case 'u': + freeze = FALSE; + break; + default: + usage(stderr); + break; + } + } + + if (freeze == -1) + errx(EXIT_FAILURE, _("no action specified")); + if (optind == argc) + errx(EXIT_FAILURE, _("no filename specified")); + path = argv[optind++]; + + if (optind != argc) { + warnx(_("unexpected number of arguments")); + usage(stderr); + } + + fd = open(path, O_RDONLY); + if (fd < 0) + err(EXIT_FAILURE, _("%s: open failed"), path); + + if (fstat(fd, &sb) == -1) { + warn(_("%s: fstat failed"), path); + goto done; + } + + if (!S_ISDIR(sb.st_mode)) { + warnx(_("%s: is not a directory"), path); + goto done; + } + + if (freeze) { + if (freeze_f(fd)) { + warn(_("%s: freeze failed"), path); + goto done; + } + } else { + if (unfreeze_f(fd)) { + warn(_("%s: unfreeze failed"), path); + goto done; + } + } + + rc = EXIT_SUCCESS; +done: + if (fd >= 0) + close(fd); + return rc; +} +