alistair23-linux/fs/gfs2/sys.c
Steven Whitehouse 97cc1025b1 GFS2: Kill two daemons with one patch
This patch removes the two daemons, gfs2_scand and gfs2_glockd
and replaces them with a shrinker which is called from the VM.

The net result is that GFS2 responds better when there is memory
pressure, since it shrinks the glock cache at the same rate
as the VFS shrinks the dcache and icache. There are no longer
any time based criteria for shrinking glocks, they are kept
until such time as the VM asks for more memory and then we
demote just as many glocks as required.

There are potential future changes to this code, including the
possibility of sorting the glocks which are to be written back
into inode number order, to get a better I/O ordering. It would
be very useful to have an elevator based workqueue implementation
for this, as that would automatically deal with the read I/O cases
at the same time.

This patch is my answer to Andrew Morton's remark, made during
the initial review of GFS2, asking why GFS2 needs so many kernel
threads, the answer being that it doesn't :-) This patch is a
net loss of about 200 lines of code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-01-05 07:39:09 +00:00

480 lines
13 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/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>
#include <asm/uaccess.h>
#include "gfs2.h"
#include "incore.h"
#include "sys.h"
#include "super.h"
#include "glock.h"
#include "quota.h"
#include "util.h"
char *gfs2_sys_margs;
spinlock_t gfs2_sys_margs_lock;
static ssize_t id_show(struct gfs2_sbd *sdp, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%u:%u\n",
MAJOR(sdp->sd_vfs->s_dev), MINOR(sdp->sd_vfs->s_dev));
}
static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%s\n", sdp->sd_fsname);
}
static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
{
unsigned int count;
mutex_lock(&sdp->sd_freeze_lock);
count = sdp->sd_freeze_count;
mutex_unlock(&sdp->sd_freeze_lock);
return snprintf(buf, PAGE_SIZE, "%u\n", count);
}
static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
ssize_t ret = len;
int error = 0;
int n = simple_strtol(buf, NULL, 0);
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
switch (n) {
case 0:
gfs2_unfreeze_fs(sdp);
break;
case 1:
error = gfs2_freeze_fs(sdp);
break;
default:
ret = -EINVAL;
}
if (error)
fs_warn(sdp, "freeze %d error %d", n, error);
return ret;
}
static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)
{
unsigned int b = test_bit(SDF_SHUTDOWN, &sdp->sd_flags);
return snprintf(buf, PAGE_SIZE, "%u\n", b);
}
static ssize_t withdraw_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (simple_strtol(buf, NULL, 0) != 1)
return -EINVAL;
gfs2_lm_withdraw(sdp,
"GFS2: fsid=%s: withdrawing from cluster at user's request\n",
sdp->sd_fsname);
return len;
}
static ssize_t statfs_sync_store(struct gfs2_sbd *sdp, const char *buf,
size_t len)
{
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (simple_strtol(buf, NULL, 0) != 1)
return -EINVAL;
gfs2_statfs_sync(sdp);
return len;
}
static ssize_t quota_sync_store(struct gfs2_sbd *sdp, const char *buf,
size_t len)
{
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (simple_strtol(buf, NULL, 0) != 1)
return -EINVAL;
gfs2_quota_sync(sdp);
return len;
}
static ssize_t quota_refresh_user_store(struct gfs2_sbd *sdp, const char *buf,
size_t len)
{
u32 id;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
id = simple_strtoul(buf, NULL, 0);
gfs2_quota_refresh(sdp, 1, id);
return len;
}
static ssize_t quota_refresh_group_store(struct gfs2_sbd *sdp, const char *buf,
size_t len)
{
u32 id;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
id = simple_strtoul(buf, NULL, 0);
gfs2_quota_refresh(sdp, 0, id);
return len;
}
struct gfs2_attr {
struct attribute attr;
ssize_t (*show)(struct gfs2_sbd *, char *);
ssize_t (*store)(struct gfs2_sbd *, const char *, size_t);
};
#define GFS2_ATTR(name, mode, show, store) \
static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store)
GFS2_ATTR(id, 0444, id_show, NULL);
GFS2_ATTR(fsname, 0444, fsname_show, NULL);
GFS2_ATTR(freeze, 0644, freeze_show, freeze_store);
GFS2_ATTR(withdraw, 0644, withdraw_show, withdraw_store);
GFS2_ATTR(statfs_sync, 0200, NULL, statfs_sync_store);
GFS2_ATTR(quota_sync, 0200, NULL, quota_sync_store);
GFS2_ATTR(quota_refresh_user, 0200, NULL, quota_refresh_user_store);
GFS2_ATTR(quota_refresh_group, 0200, NULL, quota_refresh_group_store);
static struct attribute *gfs2_attrs[] = {
&gfs2_attr_id.attr,
&gfs2_attr_fsname.attr,
&gfs2_attr_freeze.attr,
&gfs2_attr_withdraw.attr,
&gfs2_attr_statfs_sync.attr,
&gfs2_attr_quota_sync.attr,
&gfs2_attr_quota_refresh_user.attr,
&gfs2_attr_quota_refresh_group.attr,
NULL,
};
static ssize_t gfs2_attr_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
return a->show ? a->show(sdp, buf) : 0;
}
static ssize_t gfs2_attr_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t len)
{
struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
return a->store ? a->store(sdp, buf, len) : len;
}
static struct sysfs_ops gfs2_attr_ops = {
.show = gfs2_attr_show,
.store = gfs2_attr_store,
};
static struct kobj_type gfs2_ktype = {
.default_attrs = gfs2_attrs,
.sysfs_ops = &gfs2_attr_ops,
};
static struct kset *gfs2_kset;
/*
* display struct lm_lockstruct fields
*/
struct lockstruct_attr {
struct attribute attr;
ssize_t (*show)(struct gfs2_sbd *, char *);
};
#define LOCKSTRUCT_ATTR(name, fmt) \
static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf) \
{ \
return snprintf(buf, PAGE_SIZE, fmt, sdp->sd_lockstruct.ls_##name); \
} \
static struct lockstruct_attr lockstruct_attr_##name = __ATTR_RO(name)
LOCKSTRUCT_ATTR(jid, "%u\n");
LOCKSTRUCT_ATTR(first, "%u\n");
LOCKSTRUCT_ATTR(lvb_size, "%u\n");
LOCKSTRUCT_ATTR(flags, "%d\n");
static struct attribute *lockstruct_attrs[] = {
&lockstruct_attr_jid.attr,
&lockstruct_attr_first.attr,
&lockstruct_attr_lvb_size.attr,
&lockstruct_attr_flags.attr,
NULL,
};
/*
* display struct gfs2_args fields
*/
struct args_attr {
struct attribute attr;
ssize_t (*show)(struct gfs2_sbd *, char *);
};
#define ARGS_ATTR(name, fmt) \
static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf) \
{ \
return snprintf(buf, PAGE_SIZE, fmt, sdp->sd_args.ar_##name); \
} \
static struct args_attr args_attr_##name = __ATTR_RO(name)
ARGS_ATTR(lockproto, "%s\n");
ARGS_ATTR(locktable, "%s\n");
ARGS_ATTR(hostdata, "%s\n");
ARGS_ATTR(spectator, "%d\n");
ARGS_ATTR(ignore_local_fs, "%d\n");
ARGS_ATTR(localcaching, "%d\n");
ARGS_ATTR(localflocks, "%d\n");
ARGS_ATTR(debug, "%d\n");
ARGS_ATTR(upgrade, "%d\n");
ARGS_ATTR(posix_acl, "%d\n");
ARGS_ATTR(quota, "%u\n");
ARGS_ATTR(suiddir, "%d\n");
ARGS_ATTR(data, "%d\n");
static struct attribute *args_attrs[] = {
&args_attr_lockproto.attr,
&args_attr_locktable.attr,
&args_attr_hostdata.attr,
&args_attr_spectator.attr,
&args_attr_ignore_local_fs.attr,
&args_attr_localcaching.attr,
&args_attr_localflocks.attr,
&args_attr_debug.attr,
&args_attr_upgrade.attr,
&args_attr_posix_acl.attr,
&args_attr_quota.attr,
&args_attr_suiddir.attr,
&args_attr_data.attr,
NULL,
};
/*
* get and set struct gfs2_tune fields
*/
static ssize_t quota_scale_show(struct gfs2_sbd *sdp, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%u %u\n",
sdp->sd_tune.gt_quota_scale_num,
sdp->sd_tune.gt_quota_scale_den);
}
static ssize_t quota_scale_store(struct gfs2_sbd *sdp, const char *buf,
size_t len)
{
struct gfs2_tune *gt = &sdp->sd_tune;
unsigned int x, y;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (sscanf(buf, "%u %u", &x, &y) != 2 || !y)
return -EINVAL;
spin_lock(&gt->gt_spin);
gt->gt_quota_scale_num = x;
gt->gt_quota_scale_den = y;
spin_unlock(&gt->gt_spin);
return len;
}
static ssize_t tune_set(struct gfs2_sbd *sdp, unsigned int *field,
int check_zero, const char *buf, size_t len)
{
struct gfs2_tune *gt = &sdp->sd_tune;
unsigned int x;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
x = simple_strtoul(buf, NULL, 0);
if (check_zero && !x)
return -EINVAL;
spin_lock(&gt->gt_spin);
*field = x;
spin_unlock(&gt->gt_spin);
return len;
}
struct tune_attr {
struct attribute attr;
ssize_t (*show)(struct gfs2_sbd *, char *);
ssize_t (*store)(struct gfs2_sbd *, const char *, size_t);
};
#define TUNE_ATTR_3(name, show, store) \
static struct tune_attr tune_attr_##name = __ATTR(name, 0644, show, store)
#define TUNE_ATTR_2(name, store) \
static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf) \
{ \
return snprintf(buf, PAGE_SIZE, "%u\n", sdp->sd_tune.gt_##name); \
} \
TUNE_ATTR_3(name, name##_show, store)
#define TUNE_ATTR(name, check_zero) \
static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
{ \
return tune_set(sdp, &sdp->sd_tune.gt_##name, check_zero, buf, len); \
} \
TUNE_ATTR_2(name, name##_store)
#define TUNE_ATTR_DAEMON(name, process) \
static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
{ \
ssize_t r = tune_set(sdp, &sdp->sd_tune.gt_##name, 1, buf, len); \
wake_up_process(sdp->sd_##process); \
return r; \
} \
TUNE_ATTR_2(name, name##_store)
TUNE_ATTR(incore_log_blocks, 0);
TUNE_ATTR(log_flush_secs, 0);
TUNE_ATTR(quota_warn_period, 0);
TUNE_ATTR(quota_quantum, 0);
TUNE_ATTR(max_readahead, 0);
TUNE_ATTR(complain_secs, 0);
TUNE_ATTR(statfs_slow, 0);
TUNE_ATTR(new_files_jdata, 0);
TUNE_ATTR(quota_simul_sync, 1);
TUNE_ATTR(quota_cache_secs, 1);
TUNE_ATTR(stall_secs, 1);
TUNE_ATTR(statfs_quantum, 1);
TUNE_ATTR_DAEMON(recoverd_secs, recoverd_process);
TUNE_ATTR_DAEMON(logd_secs, logd_process);
TUNE_ATTR_3(quota_scale, quota_scale_show, quota_scale_store);
static struct attribute *tune_attrs[] = {
&tune_attr_incore_log_blocks.attr,
&tune_attr_log_flush_secs.attr,
&tune_attr_quota_warn_period.attr,
&tune_attr_quota_quantum.attr,
&tune_attr_max_readahead.attr,
&tune_attr_complain_secs.attr,
&tune_attr_statfs_slow.attr,
&tune_attr_quota_simul_sync.attr,
&tune_attr_quota_cache_secs.attr,
&tune_attr_stall_secs.attr,
&tune_attr_statfs_quantum.attr,
&tune_attr_recoverd_secs.attr,
&tune_attr_logd_secs.attr,
&tune_attr_quota_scale.attr,
&tune_attr_new_files_jdata.attr,
NULL,
};
static struct attribute_group lockstruct_group = {
.name = "lockstruct",
.attrs = lockstruct_attrs,
};
static struct attribute_group args_group = {
.name = "args",
.attrs = args_attrs,
};
static struct attribute_group tune_group = {
.name = "tune",
.attrs = tune_attrs,
};
int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
{
int error;
sdp->sd_kobj.kset = gfs2_kset;
error = kobject_init_and_add(&sdp->sd_kobj, &gfs2_ktype, NULL,
"%s", sdp->sd_table_name);
if (error)
goto fail;
error = sysfs_create_group(&sdp->sd_kobj, &lockstruct_group);
if (error)
goto fail_reg;
error = sysfs_create_group(&sdp->sd_kobj, &args_group);
if (error)
goto fail_lockstruct;
error = sysfs_create_group(&sdp->sd_kobj, &tune_group);
if (error)
goto fail_args;
kobject_uevent(&sdp->sd_kobj, KOBJ_ADD);
return 0;
fail_args:
sysfs_remove_group(&sdp->sd_kobj, &args_group);
fail_lockstruct:
sysfs_remove_group(&sdp->sd_kobj, &lockstruct_group);
fail_reg:
kobject_put(&sdp->sd_kobj);
fail:
fs_err(sdp, "error %d adding sysfs files", error);
return error;
}
void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
{
sysfs_remove_group(&sdp->sd_kobj, &tune_group);
sysfs_remove_group(&sdp->sd_kobj, &args_group);
sysfs_remove_group(&sdp->sd_kobj, &lockstruct_group);
kobject_put(&sdp->sd_kobj);
}
int gfs2_sys_init(void)
{
gfs2_sys_margs = NULL;
spin_lock_init(&gfs2_sys_margs_lock);
gfs2_kset = kset_create_and_add("gfs2", NULL, fs_kobj);
if (!gfs2_kset)
return -ENOMEM;
return 0;
}
void gfs2_sys_uninit(void)
{
kfree(gfs2_sys_margs);
kset_unregister(gfs2_kset);
}