From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17670 invoked by alias); 29 Oct 2010 16:43:55 -0000 Received: (qmail 17651 invoked by uid 9699); 29 Oct 2010 16:43:53 -0000 Date: Fri, 29 Oct 2010 16:43:00 -0000 Message-ID: <20101029164353.17649.qmail@sourceware.org> From: mornfall@sourceware.org To: lvm-devel@redhat.com, lvm2-cvs@sourceware.org Subject: LVM2 daemons/dmeventd/plugins/snapshot/dmevent ... Mailing-List: contact lvm2-cvs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: lvm2-cvs-owner@sourceware.org X-SW-Source: 2010-10/txt/msg00105.txt.bz2 CVSROOT: /cvs/lvm2 Module name: LVM2 Changes by: mornfall@sourceware.org 2010-10-29 16:43:52 Modified files: daemons/dmeventd/plugins/snapshot: dmeventd_snapshot.c test : test-utils.sh Added files: test : t-snapshot-autoumount-dmeventd.sh Log message: Add code to the dmeventd snapshot plugin to automatically unmount snapshots that have been invalidated. Patches: http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c.diff?cvsroot=lvm2&r1=1.11&r2=1.12 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/test/t-snapshot-autoumount-dmeventd.sh.diff?cvsroot=lvm2&r1=NONE&r2=1.1 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/test/test-utils.sh.diff?cvsroot=lvm2&r1=1.54&r2=1.55 --- LVM2/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c 2010/10/15 16:28:14 1.11 +++ LVM2/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c 2010/10/29 16:43:51 1.12 @@ -21,6 +21,7 @@ #include "lvm-string.h" +#include #include /* FIXME Replace syslog with multilog */ /* FIXME Missing openlog? */ @@ -31,6 +32,8 @@ /* Do not bother checking snapshots less than 50% full. */ #define CHECK_MINIMUM 50 +#define UMOUNT_COMMAND "/bin/umount" + struct snap_status { int invalid; int used; @@ -71,6 +74,47 @@ status->max = atoi(p); } +static int _run(const char *cmd, ...) +{ + va_list ap; + int argc = 1; /* for argv[0], i.e. cmd */ + int i = 0; + const char **argv; + pid_t pid = fork(); + int status; + + if (pid == 0) { /* child */ + va_start(ap, cmd); + while (va_arg(ap, const char *)) + ++ argc; + va_end(ap); + + /* + 1 for the terminating NULL */ + argv = alloca(sizeof(const char *) * (argc + 1)); + + argv[0] = cmd; + va_start(ap, cmd); + while ((argv[++i] = va_arg(ap, const char *))); + va_end(ap); + + execvp(cmd, (char **)argv); + syslog(LOG_ERR, "Failed to execute %s: %s.\n", cmd, strerror(errno)); + exit(127); + } + + if (pid > 0) { /* parent */ + if (waitpid(pid, &status, 0) != pid) + return 0; /* waitpid failed */ + if (!WIFEXITED(status) || WEXITSTATUS(status)) + return 0; /* the child failed */ + } + + if (pid < 0) + return 0; /* fork failed */ + + return 1; /* all good */ +} + static int _extend(const char *device) { char *vg = NULL, *lv = NULL, *layer = NULL; @@ -93,6 +137,41 @@ return r == ECMD_PROCESSED; } +static void _umount(const char *device, int major, int minor) +{ + FILE *mounts; + char buffer[4096]; + char *words[3]; + struct stat st; + + if (!(mounts = fopen("/proc/mounts", "r"))) { + syslog(LOG_ERR, "Could not read /proc/mounts. Not umounting %s.\n", device); + return; + } + + while (!feof(mounts)) { + /* read a line of /proc/mounts */ + if (!fgets(buffer, sizeof(buffer), mounts)) + break; /* eof, likely */ + + /* words[0] is the mount point and words[1] is the device path */ + dm_split_words(buffer, 3, 0, words); + + /* find the major/minor of the device */ + if (stat(words[0], &st)) + continue; /* can't stat, skip this one */ + + if (S_ISBLK(st.st_mode) && + major(st.st_rdev) == major && + minor(st.st_rdev) == minor) { + syslog(LOG_ERR, "Unmounting invalid snapshot %s from %s.", device, words[1]); + if (!_run(UMOUNT_COMMAND, "-fl", words[1], NULL)) + syslog(LOG_ERR, "Failed to umount snapshot %s from %s: %s.", + device, words[1], strerror(errno)); + } + } +} + void process_event(struct dm_task *dmt, enum dm_event_mask event __attribute__((unused)), void **private) @@ -117,6 +196,16 @@ _parse_snapshot_params(params, &status); + if (status.invalid) { + syslog(LOG_ERR, "Trying to umount invalid snapshot %s...\n", device); + struct dm_info info; + if (dm_task_get_info(dmt, &info)) { + dmeventd_lvm2_unlock(); + _umount(device, info.major, info.minor); + return; + } /* else; too bad, but this is best-effort thing... */ + } + /* * If the snapshot has been invalidated or we failed to parse * the status string. Report the full status string to syslog. /cvs/lvm2/LVM2/test/t-snapshot-autoumount-dmeventd.sh,v --> standard output revision 1.1 --- LVM2/test/t-snapshot-autoumount-dmeventd.sh +++ - 2010-10-29 16:43:52.931121000 +0000 @@ -0,0 +1,41 @@ +#!/bin/bash +# Copyright (C) 2010 Red Hat, Inc. All rights reserved. +# +# This copyrighted material is made available to anyone wishing to use, +# modify, copy, or redistribute it subject to the terms and conditions +# of the GNU General Public License v.2. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software Foundation, +# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +# no automatic extensions please +LVM_TEST_CONFIG_SNAPSHOT_AUTOEXTEND=" + snapshot_autoextend_percent = 0 + snapshot_autoextend_threshold = 100" + +. ./test-utils.sh + +which mkfs.ext2 || exit 200 + +prepare_lvmconf + +aux prepare_vg 2 +aux prepare_dmeventd + +lvcreate -l 8 -n base $vg +mkfs.ext2 $DM_DEV_DIR/$vg/base + +lvcreate -s -l 4 -n snap $vg/base +lvchange --monitor y $vg/snap + +mkdir mnt +mount $DM_DEV_DIR/$vg/snap mnt +mount +cat /proc/mounts | grep $vg-snap + +dd if=/dev/zero of=mnt/file$1 bs=1M count=17 +sync +sleep 10 # dmeventd only checks every 10 seconds :( + +cat /proc/mounts | not grep $vg-snap --- LVM2/test/test-utils.sh 2010/10/26 01:25:46 1.54 +++ LVM2/test/test-utils.sh 2010/10/29 16:43:52 1.55 @@ -121,6 +121,7 @@ init_udev_transaction while dmsetup table | grep -q ^$PREFIX; do for s in `dmsetup info -c -o name --noheading | grep ^$PREFIX`; do + umount -fl $DM_DEV_DIR/mapper/$s || true dmsetup remove $s >& /dev/null || true done done @@ -360,6 +361,11 @@ test -z "$filter" && \ filter='[ "a/dev\/mirror/", "a/dev\/mapper\/.*pv[0-9_]*$/", "r/.*/" ]' locktype= + if test -z "$LVM_TEST_CONFIG_SNAPSHOT_AUTOEXTEND"; then + LVM_TEST_CONFIG_SNAPSHOT_AUTOEXTEND=" + snapshot_autoextend_percent = 50 + snapshot_autoextend_threshold = 50" + fi if test -n "$LVM_TEST_LOCKING"; then locktype="locking_type = $LVM_TEST_LOCKING"; fi cat > $TESTDIR/etc/lvm.conf.new <<-EOF $LVM_TEST_CONFIG @@ -395,8 +401,7 @@ udev_sync = 1 udev_rules = 1 polling_interval = 0 - snapshot_autoextend_percent = 50 - snapshot_autoextend_threshold = 50 + $LVM_TEST_CONFIG_SNAPSHOT_AUTOEXTEND } EOF # FIXME remove this workaround after mmap & truncating file problems solved