android_kernel_motorola_sm6225/fs/gfs2/glops.c
Steven Whitehouse 6802e3400f [GFS2] Clean up the glock core
This patch implements a number of cleanups to the core of the
GFS2 glock code. As a result a lot of code is removed. It looks
like a really big change, but actually a large part of this patch
is either removing or moving existing code.

There are some new bits too though, such as the new run_queue()
function which is considerably streamlined. Highlights of this
patch include:

 o Fixes a cluster coherency bug during SH -> EX lock conversions
 o Removes the "glmutex" code in favour of a single bit lock
 o Removes the ->go_xmote_bh() for inodes since it was duplicating
   ->go_lock()
 o We now only use the ->lm_lock() function for both locks and
   unlocks (i.e. unlock is a lock with target mode LM_ST_UNLOCKED)
 o The fast path is considerably shortly, giving performance gains
   especially with lock_nolock
 o The glock_workqueue is now used for all the callbacks from the DLM
   which allows us to simplify the lock_dlm module (see following patch)
 o The way is now open to make further changes such as eliminating the two
   threads (gfs2_glockd and gfs2_scand) in favour of a more efficient
   scheme.

This patch has undergone extensive testing with various test suites
so it should be pretty stable by now.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
2008-06-27 09:39:22 +01:00

440 lines
9.7 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/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/bio.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "recovery.h"
#include "rgrp.h"
#include "util.h"
#include "trans.h"
/**
* ail_empty_gl - remove all buffers for a given lock from the AIL
* @gl: the glock
*
* None of the buffers should be dirty, locked, or pinned.
*/
static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
unsigned int blocks;
struct list_head *head = &gl->gl_ail_list;
struct gfs2_bufdata *bd;
struct buffer_head *bh;
int error;
blocks = atomic_read(&gl->gl_ail_count);
if (!blocks)
return;
error = gfs2_trans_begin(sdp, 0, blocks);
if (gfs2_assert_withdraw(sdp, !error))
return;
gfs2_log_lock(sdp);
while (!list_empty(head)) {
bd = list_entry(head->next, struct gfs2_bufdata,
bd_ail_gl_list);
bh = bd->bd_bh;
gfs2_remove_from_ail(bd);
bd->bd_bh = NULL;
bh->b_private = NULL;
bd->bd_blkno = bh->b_blocknr;
gfs2_assert_withdraw(sdp, !buffer_busy(bh));
gfs2_trans_add_revoke(sdp, bd);
}
gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
gfs2_log_unlock(sdp);
gfs2_trans_end(sdp);
gfs2_log_flush(sdp, NULL);
}
/**
* gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
* @gl: the glock
*
*/
static void gfs2_pte_inval(struct gfs2_glock *gl)
{
struct gfs2_inode *ip;
struct inode *inode;
ip = gl->gl_object;
inode = &ip->i_inode;
if (!ip || !S_ISREG(inode->i_mode))
return;
unmap_shared_mapping_range(inode->i_mapping, 0, 0);
if (test_bit(GIF_SW_PAGED, &ip->i_flags))
set_bit(GLF_DIRTY, &gl->gl_flags);
}
/**
* meta_go_sync - sync out the metadata for this glock
* @gl: the glock
*
* Called when demoting or unlocking an EX glock. We must flush
* to disk all dirty buffers/pages relating to this glock, and must not
* not return to caller to demote/unlock the glock until I/O is complete.
*/
static void meta_go_sync(struct gfs2_glock *gl)
{
if (gl->gl_state != LM_ST_EXCLUSIVE)
return;
if (test_and_clear_bit(GLF_DIRTY, &gl->gl_flags)) {
gfs2_log_flush(gl->gl_sbd, gl);
gfs2_meta_sync(gl);
gfs2_ail_empty_gl(gl);
}
}
/**
* meta_go_inval - invalidate the metadata for this glock
* @gl: the glock
* @flags:
*
*/
static void meta_go_inval(struct gfs2_glock *gl, int flags)
{
if (!(flags & DIO_METADATA))
return;
gfs2_meta_inval(gl);
if (gl->gl_object == GFS2_I(gl->gl_sbd->sd_rindex))
gl->gl_sbd->sd_rindex_uptodate = 0;
else if (gl->gl_ops == &gfs2_rgrp_glops && gl->gl_object) {
struct gfs2_rgrpd *rgd = (struct gfs2_rgrpd *)gl->gl_object;
rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
}
}
/**
* inode_go_sync - Sync the dirty data and/or metadata for an inode glock
* @gl: the glock protecting the inode
*
*/
static void inode_go_sync(struct gfs2_glock *gl)
{
struct gfs2_inode *ip = gl->gl_object;
struct address_space *metamapping = gl->gl_aspace->i_mapping;
int error;
if (gl->gl_state != LM_ST_UNLOCKED)
gfs2_pte_inval(gl);
if (gl->gl_state != LM_ST_EXCLUSIVE)
return;
if (ip && !S_ISREG(ip->i_inode.i_mode))
ip = NULL;
if (test_bit(GLF_DIRTY, &gl->gl_flags)) {
gfs2_log_flush(gl->gl_sbd, gl);
filemap_fdatawrite(metamapping);
if (ip) {
struct address_space *mapping = ip->i_inode.i_mapping;
filemap_fdatawrite(mapping);
error = filemap_fdatawait(mapping);
mapping_set_error(mapping, error);
}
error = filemap_fdatawait(metamapping);
mapping_set_error(metamapping, error);
clear_bit(GLF_DIRTY, &gl->gl_flags);
gfs2_ail_empty_gl(gl);
}
}
/**
* inode_go_inval - prepare a inode glock to be released
* @gl: the glock
* @flags:
*
*/
static void inode_go_inval(struct gfs2_glock *gl, int flags)
{
struct gfs2_inode *ip = gl->gl_object;
int meta = (flags & DIO_METADATA);
if (meta) {
gfs2_meta_inval(gl);
if (ip)
set_bit(GIF_INVALID, &ip->i_flags);
}
if (ip && S_ISREG(ip->i_inode.i_mode))
truncate_inode_pages(ip->i_inode.i_mapping, 0);
}
/**
* inode_go_demote_ok - Check to see if it's ok to unlock an inode glock
* @gl: the glock
*
* Returns: 1 if it's ok
*/
static int inode_go_demote_ok(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
int demote = 0;
if (!gl->gl_object && !gl->gl_aspace->i_mapping->nrpages)
demote = 1;
else if (!sdp->sd_args.ar_localcaching &&
time_after_eq(jiffies, gl->gl_stamp +
gfs2_tune_get(sdp, gt_demote_secs) * HZ))
demote = 1;
return demote;
}
/**
* inode_go_lock - operation done after an inode lock is locked by a process
* @gl: the glock
* @flags:
*
* Returns: errno
*/
static int inode_go_lock(struct gfs2_holder *gh)
{
struct gfs2_glock *gl = gh->gh_gl;
struct gfs2_inode *ip = gl->gl_object;
int error = 0;
if (!ip || (gh->gh_flags & GL_SKIP))
return 0;
if (test_bit(GIF_INVALID, &ip->i_flags)) {
error = gfs2_inode_refresh(ip);
if (error)
return error;
}
if ((ip->i_di.di_flags & GFS2_DIF_TRUNC_IN_PROG) &&
(gl->gl_state == LM_ST_EXCLUSIVE) &&
(gh->gh_state == LM_ST_EXCLUSIVE))
error = gfs2_truncatei_resume(ip);
return error;
}
/**
* inode_go_dump - print information about an inode
* @seq: The iterator
* @ip: the inode
*
* Returns: 0 on success, -ENOBUFS when we run out of space
*/
static int inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
{
const struct gfs2_inode *ip = gl->gl_object;
if (ip == NULL)
return 0;
gfs2_print_dbg(seq, " I: n:%llu/%llu t:%u f:0x%08lx\n",
(unsigned long long)ip->i_no_formal_ino,
(unsigned long long)ip->i_no_addr,
IF2DT(ip->i_inode.i_mode), ip->i_flags);
return 0;
}
/**
* rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock
* @gl: the glock
*
* Returns: 1 if it's ok
*/
static int rgrp_go_demote_ok(struct gfs2_glock *gl)
{
return !gl->gl_aspace->i_mapping->nrpages;
}
/**
* rgrp_go_lock - operation done after an rgrp lock is locked by
* a first holder on this node.
* @gl: the glock
* @flags:
*
* Returns: errno
*/
static int rgrp_go_lock(struct gfs2_holder *gh)
{
return gfs2_rgrp_bh_get(gh->gh_gl->gl_object);
}
/**
* rgrp_go_unlock - operation done before an rgrp lock is unlocked by
* a last holder on this node.
* @gl: the glock
* @flags:
*
*/
static void rgrp_go_unlock(struct gfs2_holder *gh)
{
gfs2_rgrp_bh_put(gh->gh_gl->gl_object);
}
/**
* rgrp_go_dump - print out an rgrp
* @seq: The iterator
* @gl: The glock in question
*
*/
static int rgrp_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
{
const struct gfs2_rgrpd *rgd = gl->gl_object;
if (rgd == NULL)
return 0;
gfs2_print_dbg(seq, " R: n:%llu\n", (unsigned long long)rgd->rd_addr);
return 0;
}
/**
* trans_go_sync - promote/demote the transaction glock
* @gl: the glock
* @state: the requested state
* @flags:
*
*/
static void trans_go_sync(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
if (gl->gl_state != LM_ST_UNLOCKED &&
test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
gfs2_meta_syncfs(sdp);
gfs2_log_shutdown(sdp);
}
}
/**
* trans_go_xmote_bh - After promoting/demoting the transaction glock
* @gl: the glock
*
*/
static int trans_go_xmote_bh(struct gfs2_glock *gl, struct gfs2_holder *gh)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
struct gfs2_glock *j_gl = ip->i_gl;
struct gfs2_log_header_host head;
int error;
if (test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
error = gfs2_find_jhead(sdp->sd_jdesc, &head);
if (error)
gfs2_consist(sdp);
if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
gfs2_consist(sdp);
/* Initialize some head of the log stuff */
if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
sdp->sd_log_sequence = head.lh_sequence + 1;
gfs2_log_pointers_init(sdp, head.lh_blkno);
}
}
return 0;
}
/**
* quota_go_demote_ok - Check to see if it's ok to unlock a quota glock
* @gl: the glock
*
* Returns: 1 if it's ok
*/
static int quota_go_demote_ok(struct gfs2_glock *gl)
{
return !atomic_read(&gl->gl_lvb_count);
}
const struct gfs2_glock_operations gfs2_meta_glops = {
.go_xmote_th = meta_go_sync,
.go_type = LM_TYPE_META,
};
const struct gfs2_glock_operations gfs2_inode_glops = {
.go_xmote_th = inode_go_sync,
.go_inval = inode_go_inval,
.go_demote_ok = inode_go_demote_ok,
.go_lock = inode_go_lock,
.go_dump = inode_go_dump,
.go_type = LM_TYPE_INODE,
.go_min_hold_time = HZ / 5,
};
const struct gfs2_glock_operations gfs2_rgrp_glops = {
.go_xmote_th = meta_go_sync,
.go_inval = meta_go_inval,
.go_demote_ok = rgrp_go_demote_ok,
.go_lock = rgrp_go_lock,
.go_unlock = rgrp_go_unlock,
.go_dump = rgrp_go_dump,
.go_type = LM_TYPE_RGRP,
.go_min_hold_time = HZ / 5,
};
const struct gfs2_glock_operations gfs2_trans_glops = {
.go_xmote_th = trans_go_sync,
.go_xmote_bh = trans_go_xmote_bh,
.go_type = LM_TYPE_NONDISK,
};
const struct gfs2_glock_operations gfs2_iopen_glops = {
.go_type = LM_TYPE_IOPEN,
};
const struct gfs2_glock_operations gfs2_flock_glops = {
.go_type = LM_TYPE_FLOCK,
};
const struct gfs2_glock_operations gfs2_nondisk_glops = {
.go_type = LM_TYPE_NONDISK,
};
const struct gfs2_glock_operations gfs2_quota_glops = {
.go_demote_ok = quota_go_demote_ok,
.go_type = LM_TYPE_QUOTA,
};
const struct gfs2_glock_operations gfs2_journal_glops = {
.go_type = LM_TYPE_JOURNAL,
};