int
umount_fs(char *mntdir, const char *mnttabname, u_int unmount_flags)
{
int error;
eintr:
error = umount(mntdir, MNT_NOFORCE);
if (error < 0)
error = errno;
switch (error) {
case EINVAL:
case ENOTBLK:
plog(XLOG_WARNING, "unmount: %s is not mounted", mntdir);
error = 0; /* Not really an error */
break;
case ENOENT:
plog(XLOG_ERROR, "mount point %s: %m", mntdir);
break;
case EINTR:
/* not sure why this happens, but it does. ask kirk one day... */
dlog("%s: unmount: %m", mntdir);
goto eintr;
#ifdef MNT2_GEN_OPT_FORCE
case EBUSY:
case EIO:
case ESTALE:
/* caller determines if forced unmounts should be used */
if (unmount_flags & AMU_UMOUNT_FORCE) {
error = umount2_fs(mntdir, unmount_flags);
if ((error = umount2_fs(mntdir, unmount_flags)) < 0)
error = errno;
else
return error;
}
/* fallthrough */
#endif /* MNT2_GEN_OPT_FORCE */
default:
dlog("%s: unmount: %m", mntdir);
break;
}
return error;
}
/*
* Initialize a top-level mount. In our case, if the user asked for
* forced_unmounts, and the OS supports it, then we try forced/lazy unmounts
* on any previous toplvl mounts. This is useful if a previous Amd died and
* left behind toplvl mount points (this Amd will clean them up).
*
* WARNING: Don't use forced/lazy unmounts if you have another valid Amd
* running, because this code WILL force those valid toplvl mount points to
* be detached as well!
*/
static int
amfs_toplvl_init(mntfs *mf)
{
int error = 0;
#if (defined(MNT2_GEN_OPT_FORCE) || defined(MNT2_GEN_OPT_DETACH)) && (defined(HAVE_UVMOUNT) || defined(HAVE_UMOUNT2))
if (gopt.flags & CFM_FORCED_UNMOUNTS) {
plog(XLOG_INFO, "amfs_toplvl_init: trying forced/lazy unmount of %s",
mf->mf_mount);
error = umount2_fs(mf->mf_mount, AMU_UMOUNT_FORCE | AMU_UMOUNT_DETACH);
if (error)
plog(XLOG_INFO, "amfs_toplvl_init: forced/lazy unmount failed: %m");
else
dlog("amfs_toplvl_init: forced/lazy unmount succeeded");
}
#endif /* (MNT2_GEN_OPT_FORCE || MNT2_GEN_OPT_DETACH) && (HAVE_UVMOUNT || HAVE_UMOUNT2) */
return error;
}
int
umount_fs(char *mntdir, const char *mnttabname, u_int unmount_flags)
{
mntlist *mlist, *mp, *mp_save = NULL;
int error = 0;
#ifdef HAVE_LOOP_DEVICE
char *opt, *xopts = NULL;
char loopstr[] = "loop=";
char *loopdev;
#endif /* HAVE_LOOP_DEVICE */
unsigned int retries = 8;
mp = mlist = read_mtab(mntdir, mnttabname);
/*
* Search the mount table looking for
* the correct (ie last) matching entry
*/
while (mp) {
if (STREQ(mp->mnt->mnt_dir, mntdir))
mp_save = mp;
mp = mp->mnext;
}
if (!mp_save) {
plog(XLOG_ERROR, "Couldn't find how to unmount %s", mntdir);
/* Assume it is already unmounted */
error = 0;
goto out;
}
plog(XLOG_ERROR, "Trying unmount %s, umount_flags 0x%x", mp_save->mnt->mnt_dir, unmount_flags);
dlog("Trying unmount(%s)", mp_save->mnt->mnt_dir);
#ifdef MOUNT_TABLE_ON_FILE
/*
* This unmount may hang leaving this process with an exclusive lock on
* /etc/mtab. Therefore it is necessary to unlock mtab, do the unmount,
* then lock mtab (again) and reread it and finally update it.
*/
unlock_mntlist();
#endif /* MOUNT_TABLE_ON_FILE */
again:
#if defined(HAVE_UMOUNT2) && defined(MNT2_GEN_OPT_DETACH)
/*
* If user asked to try forced unmounts, then do a quick check to see if
* the mount point is hung badly. If so, then try to detach it by
* force; if the latter works, we're done.
*/
if (unmount_flags & AMU_UMOUNT_DETACH) {
/*
* Note: we pass both DETACH and FORCE flags, because umount2_fs below
* (on Linux), should try FORCE before DETACH (the latter always
* succeeds).
*/
error = umount2_fs(mp_save->mnt->mnt_dir,
unmount_flags & (AMU_UMOUNT_DETACH|AMU_UMOUNT_FORCE));
} else
#endif /* defined(HAVE_UMOUNT2) && defined(MNT2_GEN_OPT_DETACH) */
error = UNMOUNT_TRAP(mp_save->mnt);
/* Linux kernel can be sluggish for some reason */
if (error == EBUSY && retries--) {
struct timespec tm = {0, 200000000};
nanosleep(&tm, NULL);
goto again;
}
if (error < 0) {
plog(XLOG_WARNING, "unmount(%s) failed: %m", mp_save->mnt->mnt_dir);
switch ((error = errno)) {
case EINVAL:
case ENOTBLK:
plog(XLOG_WARNING, "unmount: %s is not mounted", mp_save->mnt->mnt_dir);
error = 0; /* Not really an error */
break;
case ENOENT:
/*
* This could happen if the kernel insists on following symlinks
* when we try to unmount a direct mountpoint. We need to propagate
* the error up so that the top layers know it failed and don't
* try to rmdir() the mountpoint or other silly things.
*/
plog(XLOG_ERROR, "mount point %s: %m", mp_save->mnt->mnt_dir);
break;
#if defined(HAVE_UMOUNT2) && defined(MNT2_GEN_OPT_FORCE)
case EBUSY:
/*
* Caller determines if forced unmounts should be used now (for
* EBUSY). If caller asked to force an unmount, *and* the above
* "trivial" unmount attempt failed with EBUSY, then try to force
* the unmount.
*/
if (unmount_flags & AMU_UMOUNT_FORCE) {
error = umount2_fs(mp_save->mnt->mnt_dir,
unmount_flags & AMU_UMOUNT_FORCE);
if (error < 0) {
plog(XLOG_WARNING, "%s: unmount/force: %m",
mp_save->mnt->mnt_dir);
error = errno;
}
}
break;
#endif /* defined(HAVE_UMOUNT2) && defined(MNT2_GEN_OPT_FORCE) */
default:
dlog("%s: unmount: %m", mp_save->mnt->mnt_dir);
break;
}
} else {
dlog("unmount(%s) succeeded", mp_save->mnt->mnt_dir);
}
dlog("Finished unmount(%s)", mp_save->mnt->mnt_dir);
/*
* If we are successful or there was an ENOENT, remove
* the mount entry from the mtab file.
*/
if (error && error != ENOENT)
goto out;
#ifdef HAVE_LOOP_DEVICE
/* look for loop=/dev/loopX in mnt_opts */
xopts = xstrdup(mp_save->mnt->mnt_opts); /* b/c strtok is destructive */
for (opt = strtok(xopts, ","); opt; opt = strtok(NULL, ","))
if (NSTREQ(opt, loopstr, sizeof(loopstr) - 1)) {
loopdev = opt + sizeof(loopstr) - 1;
if (delete_loop_device(loopdev) < 0)
plog(XLOG_WARNING, "unmount() failed to release loop device %s: %m", loopdev);
else
plog(XLOG_INFO, "unmount() released loop device %s OK", loopdev);
break;
}
if (xopts)
XFREE(xopts);
#endif /* HAVE_LOOP_DEVICE */
#ifdef MOUNT_TABLE_ON_FILE
free_mntlist(mlist);
mp = mlist = read_mtab(mntdir, mnttabname);
/*
* Search the mount table looking for
* the correct (ie last) matching entry
*/
mp_save = NULL;
while (mp) {
if (STREQ(mp->mnt->mnt_dir, mntdir))
mp_save = mp;
mp = mp->mnext;
}
if (mp_save) {
mnt_free(mp_save->mnt);
mp_save->mnt = NULL;
rewrite_mtab(mlist, mnttabname);
}
#endif /* MOUNT_TABLE_ON_FILE */
out:
free_mntlist(mlist);
return error;
}
int
umount_fs(char *mntdir, const char *mnttabname, u_int unmount_flags)
{
mntlist *mlist, *mp, *mp_save = NULL;
int error = 0;
mp = mlist = read_mtab(mntdir, mnttabname);
/*
* Search the mount table looking for
* the correct (ie last) matching entry
*/
while (mp) {
if (STREQ(mp->mnt->mnt_dir, mntdir))
mp_save = mp;
mp = mp->mnext;
}
if (mp_save) {
dlog("Trying unmount(%s)", mp_save->mnt->mnt_dir);
#ifdef MOUNT_TABLE_ON_FILE
/*
* This unmount may hang leaving this process with an exclusive lock on
* /etc/mtab. Therefore it is necessary to unlock mtab, do the unmount,
* then lock mtab (again) and reread it and finally update it.
*/
unlock_mntlist();
#endif /* MOUNT_TABLE_ON_FILE */
#ifdef NEED_AUTOFS_SPACE_HACK
if (unmount_flags & AMU_UMOUNT_AUTOFS) {
char *mnt_dir_save = mp_save->mnt->mnt_dir;
mp_save->mnt->mnt_dir = autofs_strdup_space_hack(mnt_dir_save);
error = UNMOUNT_TRAP(mp_save->mnt);
XFREE(mp_save->mnt->mnt_dir);
mp_save->mnt->mnt_dir = mnt_dir_save;
} else
#endif /* NEED_AUTOFS_SPACE_HACK */
error = UNMOUNT_TRAP(mp_save->mnt);
if (error < 0) {
switch ((error = errno)) {
case EINVAL:
case ENOTBLK:
plog(XLOG_WARNING, "unmount: %s is not mounted", mp_save->mnt->mnt_dir);
error = 0; /* Not really an error */
break;
case ENOENT:
/*
* This could happen if the kernel insists on following symlinks
* when we try to unmount a direct mountpoint. We need to propagate
* the error up so that the top layers know it failed and don't
* try to rmdir() the mountpoint or other silly things.
*/
plog(XLOG_ERROR, "mount point %s: %m", mp_save->mnt->mnt_dir);
break;
#if defined(MNT2_GEN_OPT_FORCE) && defined(HAVE_UVMOUNT)
case EBUSY:
case EIO:
case ESTALE:
/* caller determines if forced unmounts should be used */
if (unmount_flags & AMU_UMOUNT_FORCE) {
error = umount2_fs(mntdir, unmount_flags);
if (error < 0)
error = errno;
else
break; /* all is OK */
}
/* fallthrough */
#endif /* MNT2_GEN_OPT_FORCE && HAVE_UVMOUNT */
default:
dlog("%s: unmount: %m", mp_save->mnt->mnt_dir);
break;
}
}
dlog("Finished unmount(%s)", mp_save->mnt->mnt_dir);
if (!error) {
#ifdef MOUNT_TABLE_ON_FILE
free_mntlist(mlist);
mp = mlist = read_mtab(mntdir, mnttabname);
/*
* Search the mount table looking for
* the correct (ie last) matching entry
*/
mp_save = NULL;
while (mp) {
if (STREQ(mp->mnt->mnt_dir, mntdir))
mp_save = mp;
mp = mp->mnext;
}
if (mp_save) {
mnt_free(mp_save->mnt);
mp_save->mnt = NULL;
rewrite_mtab(mlist, mnttabname);
}
#endif /* MOUNT_TABLE_ON_FILE */
}
} else {
plog(XLOG_ERROR, "Couldn't find how to unmount %s", mntdir);
/*
* Assume it is already unmounted
*/
error = 0;
} /* end of "if (mp_save)" statement */
free_mntlist(mlist);
return error;
}