kernel-ark/fs/gfs2/ops_super.c
Steven Whitehouse 1bdad60633 [GFS2] Remove remote lock dropping code
There are several reasons why this is undesirable:

 1. It never happens during normal operation anyway
 2. If it does happen it causes performance to be very, very poor
 3. It isn't likely to solve the original problem (memory shortage
    on remote DLM node) it was supposed to solve
 4. It uses a bunch of arbitrary constants which are unlikely to be
    correct for any particular situation and for which the tuning seems
    to be a black art.
 5. In an N node cluster, only 1/N of the dropped locked will actually
    contribute to solving the problem on average.

So all in all we are better off without it. This also makes merging
the lock_dlm module into GFS2 a bit easier.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-06-27 09:39:44 +01:00

517 lines
12 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2008 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/statfs.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
#include "gfs2.h"
#include "incore.h"
#include "glock.h"
#include "inode.h"
#include "log.h"
#include "mount.h"
#include "ops_super.h"
#include "quota.h"
#include "recovery.h"
#include "rgrp.h"
#include "super.h"
#include "sys.h"
#include "util.h"
#include "trans.h"
#include "dir.h"
#include "eattr.h"
#include "bmap.h"
/**
* gfs2_write_inode - Make sure the inode is stable on the disk
* @inode: The inode
* @sync: synchronous write flag
*
* Returns: errno
*/
static int gfs2_write_inode(struct inode *inode, int sync)
{
struct gfs2_inode *ip = GFS2_I(inode);
/* Check this is a "normal" inode */
if (test_bit(GIF_USER, &ip->i_flags)) {
if (current->flags & PF_MEMALLOC)
return 0;
if (sync)
gfs2_log_flush(GFS2_SB(inode), ip->i_gl);
}
return 0;
}
/**
* gfs2_put_super - Unmount the filesystem
* @sb: The VFS superblock
*
*/
static void gfs2_put_super(struct super_block *sb)
{
struct gfs2_sbd *sdp = sb->s_fs_info;
int error;
if (!sdp)
return;
if (!strncmp(sb->s_type->name, "gfs2meta", 8))
return; /* Nothing to do */
/* Unfreeze the filesystem, if we need to */
mutex_lock(&sdp->sd_freeze_lock);
if (sdp->sd_freeze_count)
gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
mutex_unlock(&sdp->sd_freeze_lock);
kthread_stop(sdp->sd_quotad_process);
kthread_stop(sdp->sd_logd_process);
kthread_stop(sdp->sd_recoverd_process);
while (sdp->sd_glockd_num--)
kthread_stop(sdp->sd_glockd_process[sdp->sd_glockd_num]);
if (!(sb->s_flags & MS_RDONLY)) {
error = gfs2_make_fs_ro(sdp);
if (error)
gfs2_io_error(sdp);
}
/* At this point, we're through modifying the disk */
/* Release stuff */
iput(sdp->sd_master_dir);
iput(sdp->sd_jindex);
iput(sdp->sd_inum_inode);
iput(sdp->sd_statfs_inode);
iput(sdp->sd_rindex);
iput(sdp->sd_quota_inode);
gfs2_glock_put(sdp->sd_rename_gl);
gfs2_glock_put(sdp->sd_trans_gl);
if (!sdp->sd_args.ar_spectator) {
gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
gfs2_glock_dq_uninit(&sdp->sd_ir_gh);
gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
iput(sdp->sd_ir_inode);
iput(sdp->sd_sc_inode);
iput(sdp->sd_qc_inode);
}
gfs2_glock_dq_uninit(&sdp->sd_live_gh);
gfs2_clear_rgrpd(sdp);
gfs2_jindex_free(sdp);
/* Take apart glock structures and buffer lists */
gfs2_gl_hash_clear(sdp);
/* Unmount the locking protocol */
gfs2_lm_unmount(sdp);
/* At this point, we're through participating in the lockspace */
gfs2_sys_fs_del(sdp);
kfree(sdp);
}
/**
* gfs2_write_super
* @sb: the superblock
*
*/
static void gfs2_write_super(struct super_block *sb)
{
sb->s_dirt = 0;
}
/**
* gfs2_sync_fs - sync the filesystem
* @sb: the superblock
*
* Flushes the log to disk.
*/
static int gfs2_sync_fs(struct super_block *sb, int wait)
{
sb->s_dirt = 0;
if (wait && sb->s_fs_info)
gfs2_log_flush(sb->s_fs_info, NULL);
return 0;
}
/**
* gfs2_write_super_lockfs - prevent further writes to the filesystem
* @sb: the VFS structure for the filesystem
*
*/
static void gfs2_write_super_lockfs(struct super_block *sb)
{
struct gfs2_sbd *sdp = sb->s_fs_info;
int error;
if (test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
return;
for (;;) {
error = gfs2_freeze_fs(sdp);
if (!error)
break;
switch (error) {
case -EBUSY:
fs_err(sdp, "waiting for recovery before freeze\n");
break;
default:
fs_err(sdp, "error freezing FS: %d\n", error);
break;
}
fs_err(sdp, "retrying...\n");
msleep(1000);
}
}
/**
* gfs2_unlockfs - reallow writes to the filesystem
* @sb: the VFS structure for the filesystem
*
*/
static void gfs2_unlockfs(struct super_block *sb)
{
gfs2_unfreeze_fs(sb->s_fs_info);
}
/**
* gfs2_statfs - Gather and return stats about the filesystem
* @sb: The superblock
* @statfsbuf: The buffer
*
* Returns: 0 on success or error code
*/
static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_inode->i_sb;
struct gfs2_sbd *sdp = sb->s_fs_info;
struct gfs2_statfs_change_host sc;
int error;
if (gfs2_tune_get(sdp, gt_statfs_slow))
error = gfs2_statfs_slow(sdp, &sc);
else
error = gfs2_statfs_i(sdp, &sc);
if (error)
return error;
buf->f_type = GFS2_MAGIC;
buf->f_bsize = sdp->sd_sb.sb_bsize;
buf->f_blocks = sc.sc_total;
buf->f_bfree = sc.sc_free;
buf->f_bavail = sc.sc_free;
buf->f_files = sc.sc_dinodes + sc.sc_free;
buf->f_ffree = sc.sc_free;
buf->f_namelen = GFS2_FNAMESIZE;
return 0;
}
/**
* gfs2_remount_fs - called when the FS is remounted
* @sb: the filesystem
* @flags: the remount flags
* @data: extra data passed in (not used right now)
*
* Returns: errno
*/
static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
{
struct gfs2_sbd *sdp = sb->s_fs_info;
int error;
error = gfs2_mount_args(sdp, data, 1);
if (error)
return error;
if (sdp->sd_args.ar_spectator)
*flags |= MS_RDONLY;
else {
if (*flags & MS_RDONLY) {
if (!(sb->s_flags & MS_RDONLY))
error = gfs2_make_fs_ro(sdp);
} else if (!(*flags & MS_RDONLY) &&
(sb->s_flags & MS_RDONLY)) {
error = gfs2_make_fs_rw(sdp);
}
}
if (*flags & (MS_NOATIME | MS_NODIRATIME))
set_bit(SDF_NOATIME, &sdp->sd_flags);
else
clear_bit(SDF_NOATIME, &sdp->sd_flags);
/* Don't let the VFS update atimes. GFS2 handles this itself. */
*flags |= MS_NOATIME | MS_NODIRATIME;
return error;
}
/**
* gfs2_drop_inode - Drop an inode (test for remote unlink)
* @inode: The inode to drop
*
* If we've received a callback on an iopen lock then its because a
* remote node tried to deallocate the inode but failed due to this node
* still having the inode open. Here we mark the link count zero
* since we know that it must have reached zero if the GLF_DEMOTE flag
* is set on the iopen glock. If we didn't do a disk read since the
* remote node removed the final link then we might otherwise miss
* this event. This check ensures that this node will deallocate the
* inode's blocks, or alternatively pass the baton on to another
* node for later deallocation.
*/
static void gfs2_drop_inode(struct inode *inode)
{
struct gfs2_inode *ip = GFS2_I(inode);
if (test_bit(GIF_USER, &ip->i_flags) && inode->i_nlink) {
struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
if (gl && test_bit(GLF_DEMOTE, &gl->gl_flags))
clear_nlink(inode);
}
generic_drop_inode(inode);
}
/**
* gfs2_clear_inode - Deallocate an inode when VFS is done with it
* @inode: The VFS inode
*
*/
static void gfs2_clear_inode(struct inode *inode)
{
struct gfs2_inode *ip = GFS2_I(inode);
/* This tells us its a "real" inode and not one which only
* serves to contain an address space (see rgrp.c, meta_io.c)
* which therefore doesn't have its own glocks.
*/
if (test_bit(GIF_USER, &ip->i_flags)) {
ip->i_gl->gl_object = NULL;
gfs2_glock_schedule_for_reclaim(ip->i_gl);
gfs2_glock_put(ip->i_gl);
ip->i_gl = NULL;
if (ip->i_iopen_gh.gh_gl) {
ip->i_iopen_gh.gh_gl->gl_object = NULL;
gfs2_glock_dq_uninit(&ip->i_iopen_gh);
}
}
}
/**
* gfs2_show_options - Show mount options for /proc/mounts
* @s: seq_file structure
* @mnt: vfsmount
*
* Returns: 0 on success or error code
*/
static int gfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
{
struct gfs2_sbd *sdp = mnt->mnt_sb->s_fs_info;
struct gfs2_args *args = &sdp->sd_args;
if (args->ar_lockproto[0])
seq_printf(s, ",lockproto=%s", args->ar_lockproto);
if (args->ar_locktable[0])
seq_printf(s, ",locktable=%s", args->ar_locktable);
if (args->ar_hostdata[0])
seq_printf(s, ",hostdata=%s", args->ar_hostdata);
if (args->ar_spectator)
seq_printf(s, ",spectator");
if (args->ar_ignore_local_fs)
seq_printf(s, ",ignore_local_fs");
if (args->ar_localflocks)
seq_printf(s, ",localflocks");
if (args->ar_localcaching)
seq_printf(s, ",localcaching");
if (args->ar_debug)
seq_printf(s, ",debug");
if (args->ar_upgrade)
seq_printf(s, ",upgrade");
if (args->ar_num_glockd != GFS2_GLOCKD_DEFAULT)
seq_printf(s, ",num_glockd=%u", args->ar_num_glockd);
if (args->ar_posix_acl)
seq_printf(s, ",acl");
if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
char *state;
switch (args->ar_quota) {
case GFS2_QUOTA_OFF:
state = "off";
break;
case GFS2_QUOTA_ACCOUNT:
state = "account";
break;
case GFS2_QUOTA_ON:
state = "on";
break;
default:
state = "unknown";
break;
}
seq_printf(s, ",quota=%s", state);
}
if (args->ar_suiddir)
seq_printf(s, ",suiddir");
if (args->ar_data != GFS2_DATA_DEFAULT) {
char *state;
switch (args->ar_data) {
case GFS2_DATA_WRITEBACK:
state = "writeback";
break;
case GFS2_DATA_ORDERED:
state = "ordered";
break;
default:
state = "unknown";
break;
}
seq_printf(s, ",data=%s", state);
}
return 0;
}
/*
* We have to (at the moment) hold the inodes main lock to cover
* the gap between unlocking the shared lock on the iopen lock and
* taking the exclusive lock. I'd rather do a shared -> exclusive
* conversion on the iopen lock, but we can change that later. This
* is safe, just less efficient.
*/
static void gfs2_delete_inode(struct inode *inode)
{
struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int error;
if (!test_bit(GIF_USER, &ip->i_flags))
goto out;
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
if (unlikely(error)) {
gfs2_glock_dq_uninit(&ip->i_iopen_gh);
goto out;
}
gfs2_glock_dq_wait(&ip->i_iopen_gh);
gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, &ip->i_iopen_gh);
error = gfs2_glock_nq(&ip->i_iopen_gh);
if (error)
goto out_uninit;
if (S_ISDIR(inode->i_mode) &&
(ip->i_di.di_flags & GFS2_DIF_EXHASH)) {
error = gfs2_dir_exhash_dealloc(ip);
if (error)
goto out_unlock;
}
if (ip->i_di.di_eattr) {
error = gfs2_ea_dealloc(ip);
if (error)
goto out_unlock;
}
if (!gfs2_is_stuffed(ip)) {
error = gfs2_file_dealloc(ip);
if (error)
goto out_unlock;
}
error = gfs2_dinode_dealloc(ip);
if (error)
goto out_unlock;
error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
if (error)
goto out_unlock;
/* Needs to be done before glock release & also in a transaction */
truncate_inode_pages(&inode->i_data, 0);
gfs2_trans_end(sdp);
out_unlock:
gfs2_glock_dq(&ip->i_iopen_gh);
out_uninit:
gfs2_holder_uninit(&ip->i_iopen_gh);
gfs2_glock_dq_uninit(&gh);
if (error && error != GLR_TRYFAILED)
fs_warn(sdp, "gfs2_delete_inode: %d\n", error);
out:
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
}
static struct inode *gfs2_alloc_inode(struct super_block *sb)
{
struct gfs2_inode *ip;
ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
if (ip) {
ip->i_flags = 0;
ip->i_gl = NULL;
}
return &ip->i_inode;
}
static void gfs2_destroy_inode(struct inode *inode)
{
kmem_cache_free(gfs2_inode_cachep, inode);
}
const struct super_operations gfs2_super_ops = {
.alloc_inode = gfs2_alloc_inode,
.destroy_inode = gfs2_destroy_inode,
.write_inode = gfs2_write_inode,
.delete_inode = gfs2_delete_inode,
.put_super = gfs2_put_super,
.write_super = gfs2_write_super,
.sync_fs = gfs2_sync_fs,
.write_super_lockfs = gfs2_write_super_lockfs,
.unlockfs = gfs2_unlockfs,
.statfs = gfs2_statfs,
.remount_fs = gfs2_remount_fs,
.clear_inode = gfs2_clear_inode,
.drop_inode = gfs2_drop_inode,
.show_options = gfs2_show_options,
};