android_kernel_xiaomi_sm8350/fs/gfs2/mount.c
Steven Whitehouse 9b8df98fc8 GFS2: Fix metafs mounts
This patch is intended to fix the issues reported in bz #457798. Instead
of having the metafs as a separate filesystem, it becomes a second root
of gfs2. As a result it will appear as type gfs2 in /proc/mounts, but it
is still possible (for backwards compatibility purposes) to mount it as
type gfs2meta. A new mount flag "meta" is introduced so that its possible
to tell the two cases apart in /proc/mounts.

As a result it becomes possible to mount type gfs2 with -o meta and
get the same result as mounting type gfs2meta. So it is possible to
mount just the metafs on its own. Currently if you do this, its then
impossible to mount the "normal" root of the gfs2 filesystem without
first unmounting the metafs root. I'm not sure if thats a feature or
a bug :-)

Either way, this is a great improvement on the previous scheme and I've
verified that it works ok with bind mounts on both the "normal" root
and the metafs root in various combinations.

There were also a bunch of functions in super.c which didn't belong there,
so this moves them into ops_fstype.c where they can be static. Hopefully
the mount/umount sequence is now more obvious as a result.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
2008-08-13 09:59:40 +01:00

271 lines
5.9 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 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 version 2.
*/
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>
#include <linux/parser.h>
#include "gfs2.h"
#include "incore.h"
#include "mount.h"
#include "sys.h"
#include "util.h"
enum {
Opt_lockproto,
Opt_locktable,
Opt_hostdata,
Opt_spectator,
Opt_ignore_local_fs,
Opt_localflocks,
Opt_localcaching,
Opt_debug,
Opt_nodebug,
Opt_upgrade,
Opt_num_glockd,
Opt_acl,
Opt_noacl,
Opt_quota_off,
Opt_quota_account,
Opt_quota_on,
Opt_suiddir,
Opt_nosuiddir,
Opt_data_writeback,
Opt_data_ordered,
Opt_meta,
Opt_err,
};
static match_table_t tokens = {
{Opt_lockproto, "lockproto=%s"},
{Opt_locktable, "locktable=%s"},
{Opt_hostdata, "hostdata=%s"},
{Opt_spectator, "spectator"},
{Opt_ignore_local_fs, "ignore_local_fs"},
{Opt_localflocks, "localflocks"},
{Opt_localcaching, "localcaching"},
{Opt_debug, "debug"},
{Opt_nodebug, "nodebug"},
{Opt_upgrade, "upgrade"},
{Opt_num_glockd, "num_glockd=%d"},
{Opt_acl, "acl"},
{Opt_noacl, "noacl"},
{Opt_quota_off, "quota=off"},
{Opt_quota_account, "quota=account"},
{Opt_quota_on, "quota=on"},
{Opt_suiddir, "suiddir"},
{Opt_nosuiddir, "nosuiddir"},
{Opt_data_writeback, "data=writeback"},
{Opt_data_ordered, "data=ordered"},
{Opt_meta, "meta"},
{Opt_err, NULL}
};
/**
* gfs2_mount_args - Parse mount options
* @sdp:
* @data:
*
* Return: errno
*/
int gfs2_mount_args(struct gfs2_sbd *sdp, char *data_arg, int remount)
{
struct gfs2_args *args = &sdp->sd_args;
char *data = data_arg;
char *options, *o, *v;
int error = 0;
if (!remount) {
/* If someone preloaded options, use those instead */
spin_lock(&gfs2_sys_margs_lock);
if (gfs2_sys_margs) {
data = gfs2_sys_margs;
gfs2_sys_margs = NULL;
}
spin_unlock(&gfs2_sys_margs_lock);
/* Set some defaults */
args->ar_num_glockd = GFS2_GLOCKD_DEFAULT;
args->ar_quota = GFS2_QUOTA_DEFAULT;
args->ar_data = GFS2_DATA_DEFAULT;
}
/* Split the options into tokens with the "," character and
process them */
for (options = data; (o = strsep(&options, ",")); ) {
int token, option;
substring_t tmp[MAX_OPT_ARGS];
if (!*o)
continue;
token = match_token(o, tokens, tmp);
switch (token) {
case Opt_lockproto:
v = match_strdup(&tmp[0]);
if (!v) {
fs_info(sdp, "no memory for lockproto\n");
error = -ENOMEM;
goto out_error;
}
if (remount && strcmp(v, args->ar_lockproto)) {
kfree(v);
goto cant_remount;
}
strncpy(args->ar_lockproto, v, GFS2_LOCKNAME_LEN);
args->ar_lockproto[GFS2_LOCKNAME_LEN - 1] = 0;
kfree(v);
break;
case Opt_locktable:
v = match_strdup(&tmp[0]);
if (!v) {
fs_info(sdp, "no memory for locktable\n");
error = -ENOMEM;
goto out_error;
}
if (remount && strcmp(v, args->ar_locktable)) {
kfree(v);
goto cant_remount;
}
strncpy(args->ar_locktable, v, GFS2_LOCKNAME_LEN);
args->ar_locktable[GFS2_LOCKNAME_LEN - 1] = 0;
kfree(v);
break;
case Opt_hostdata:
v = match_strdup(&tmp[0]);
if (!v) {
fs_info(sdp, "no memory for hostdata\n");
error = -ENOMEM;
goto out_error;
}
if (remount && strcmp(v, args->ar_hostdata)) {
kfree(v);
goto cant_remount;
}
strncpy(args->ar_hostdata, v, GFS2_LOCKNAME_LEN);
args->ar_hostdata[GFS2_LOCKNAME_LEN - 1] = 0;
kfree(v);
break;
case Opt_spectator:
if (remount && !args->ar_spectator)
goto cant_remount;
args->ar_spectator = 1;
sdp->sd_vfs->s_flags |= MS_RDONLY;
break;
case Opt_ignore_local_fs:
if (remount && !args->ar_ignore_local_fs)
goto cant_remount;
args->ar_ignore_local_fs = 1;
break;
case Opt_localflocks:
if (remount && !args->ar_localflocks)
goto cant_remount;
args->ar_localflocks = 1;
break;
case Opt_localcaching:
if (remount && !args->ar_localcaching)
goto cant_remount;
args->ar_localcaching = 1;
break;
case Opt_debug:
args->ar_debug = 1;
break;
case Opt_nodebug:
args->ar_debug = 0;
break;
case Opt_upgrade:
if (remount && !args->ar_upgrade)
goto cant_remount;
args->ar_upgrade = 1;
break;
case Opt_num_glockd:
if ((error = match_int(&tmp[0], &option))) {
fs_info(sdp, "problem getting num_glockd\n");
goto out_error;
}
if (remount && option != args->ar_num_glockd)
goto cant_remount;
if (!option || option > GFS2_GLOCKD_MAX) {
fs_info(sdp, "0 < num_glockd <= %u (not %u)\n",
GFS2_GLOCKD_MAX, option);
error = -EINVAL;
goto out_error;
}
args->ar_num_glockd = option;
break;
case Opt_acl:
args->ar_posix_acl = 1;
sdp->sd_vfs->s_flags |= MS_POSIXACL;
break;
case Opt_noacl:
args->ar_posix_acl = 0;
sdp->sd_vfs->s_flags &= ~MS_POSIXACL;
break;
case Opt_quota_off:
args->ar_quota = GFS2_QUOTA_OFF;
break;
case Opt_quota_account:
args->ar_quota = GFS2_QUOTA_ACCOUNT;
break;
case Opt_quota_on:
args->ar_quota = GFS2_QUOTA_ON;
break;
case Opt_suiddir:
args->ar_suiddir = 1;
break;
case Opt_nosuiddir:
args->ar_suiddir = 0;
break;
case Opt_data_writeback:
args->ar_data = GFS2_DATA_WRITEBACK;
break;
case Opt_data_ordered:
args->ar_data = GFS2_DATA_ORDERED;
break;
case Opt_meta:
if (remount && args->ar_meta != 1)
goto cant_remount;
args->ar_meta = 1;
break;
case Opt_err:
default:
fs_info(sdp, "unknown option: %s\n", o);
error = -EINVAL;
goto out_error;
}
}
out_error:
if (error)
fs_info(sdp, "invalid mount option(s)\n");
if (data != data_arg)
kfree(data);
return error;
cant_remount:
fs_info(sdp, "can't remount with option %s\n", o);
return -EINVAL;
}