kernel-fxtec-pro1x/fs/gfs2/trans.c
Steven Whitehouse 484adff8a0 [GFS2] Update locking in log.c
Replace the lock_for_trans()/lock_for_flush() functions with an rwsem.
In fact the sd_log_flush_lock becomes an rwsem (the write part of it)
and is extended slightly to cover everything that the lock_for_flush()
used to cover. The read part of the lock is instead of lock_for_trans().

This corrects the races in the original code and reduces the code size.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-03-29 09:12:12 -05:00

196 lines
4.3 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 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 v.2.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <asm/semaphore.h>
#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "trans.h"
#include "util.h"
int gfs2_trans_begin_i(struct gfs2_sbd *sdp, unsigned int blocks,
unsigned int revokes, char *file, unsigned int line)
{
struct gfs2_trans *tr;
int error;
if (gfs2_assert_warn(sdp, !current->journal_info) ||
gfs2_assert_warn(sdp, blocks || revokes)) {
fs_warn(sdp, "(%s, %u)\n", file, line);
return -EINVAL;
}
tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);
if (!tr)
return -ENOMEM;
tr->tr_file = file;
tr->tr_line = line;
tr->tr_blocks = blocks;
tr->tr_revokes = revokes;
tr->tr_reserved = 1;
if (blocks)
tr->tr_reserved += 1 + blocks;
if (revokes)
tr->tr_reserved += gfs2_struct2blk(sdp, revokes,
sizeof(uint64_t));
INIT_LIST_HEAD(&tr->tr_list_buf);
gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED,
GL_NEVER_RECURSE, &tr->tr_t_gh);
error = gfs2_glock_nq(&tr->tr_t_gh);
if (error)
goto fail_holder_uninit;
if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
tr->tr_t_gh.gh_flags |= GL_NOCACHE;
error = -EROFS;
goto fail_gunlock;
}
error = gfs2_log_reserve(sdp, tr->tr_reserved);
if (error)
goto fail_gunlock;
current->journal_info = tr;
return 0;
fail_gunlock:
gfs2_glock_dq(&tr->tr_t_gh);
fail_holder_uninit:
gfs2_holder_uninit(&tr->tr_t_gh);
kfree(tr);
return error;
}
void gfs2_trans_end(struct gfs2_sbd *sdp)
{
struct gfs2_trans *tr;
tr = current->journal_info;
current->journal_info = NULL;
if (gfs2_assert_warn(sdp, tr))
return;
if (!tr->tr_touched) {
gfs2_log_release(sdp, tr->tr_reserved);
gfs2_glock_dq(&tr->tr_t_gh);
gfs2_holder_uninit(&tr->tr_t_gh);
kfree(tr);
return;
}
if (gfs2_assert_withdraw(sdp, tr->tr_num_buf <= tr->tr_blocks))
fs_err(sdp, "tr_num_buf = %u, tr_blocks = %u "
"tr_file = %s, tr_line = %u\n",
tr->tr_num_buf, tr->tr_blocks,
tr->tr_file, tr->tr_line);
if (gfs2_assert_withdraw(sdp, tr->tr_num_revoke <= tr->tr_revokes))
fs_err(sdp, "tr_num_revoke = %u, tr_revokes = %u "
"tr_file = %s, tr_line = %u\n",
tr->tr_num_revoke, tr->tr_revokes,
tr->tr_file, tr->tr_line);
gfs2_log_commit(sdp, tr);
gfs2_glock_dq(&tr->tr_t_gh);
gfs2_holder_uninit(&tr->tr_t_gh);
kfree(tr);
if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
gfs2_log_flush(sdp);
}
void gfs2_trans_add_gl(struct gfs2_glock *gl)
{
lops_add(gl->gl_sbd, &gl->gl_le);
}
/**
* gfs2_trans_add_bh - Add a to-be-modified buffer to the current transaction
* @gl: the glock the buffer belongs to
* @bh: The buffer to add
* @meta: True in the case of adding metadata
*
*/
void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_bufdata *bd;
bd = bh->b_private;
if (bd)
gfs2_assert(sdp, bd->bd_gl == gl);
else {
gfs2_attach_bufdata(gl, bh, meta);
bd = bh->b_private;
}
lops_add(sdp, &bd->bd_le);
}
void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, uint64_t blkno)
{
struct gfs2_revoke *rv = kmalloc(sizeof(struct gfs2_revoke),
GFP_NOFS | __GFP_NOFAIL);
lops_init_le(&rv->rv_le, &gfs2_revoke_lops);
rv->rv_blkno = blkno;
lops_add(sdp, &rv->rv_le);
}
void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, uint64_t blkno)
{
struct gfs2_revoke *rv;
int found = 0;
gfs2_log_lock(sdp);
list_for_each_entry(rv, &sdp->sd_log_le_revoke, rv_le.le_list) {
if (rv->rv_blkno == blkno) {
list_del(&rv->rv_le.le_list);
gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
sdp->sd_log_num_revoke--;
found = 1;
break;
}
}
gfs2_log_unlock(sdp);
if (found) {
struct gfs2_trans *tr = current->journal_info;
kfree(rv);
tr->tr_num_revoke_rm++;
}
}
void gfs2_trans_add_rg(struct gfs2_rgrpd *rgd)
{
lops_add(rgd->rd_sbd, &rgd->rd_le);
}