linux/fs/gfs2/trans.c
Benjamin Marzinski 16ca9412d8 GFS2: replace gfs2_ail structure with gfs2_trans
In order to allow transactions and log flushes to happen at the same
time, gfs2 needs to move the transaction accounting and active items
list code into the gfs2_trans structure.  As a first step toward this,
this patch removes the gfs2_ail structure, and handles the active items
list in the gfs_trans structure.  This keeps gfs2 from allocating an ail
structure on log flushes, and gives us a struture that can later be used
to store the transaction accounting outside of the gfs2 superblock
structure.

With this patch, at the end of a transaction, gfs2 will add the
gfs2_trans structure to the superblock if there is not one already.
This structure now has the active items fields that were previously in
gfs2_ail.  This is not necessary in the case where the transaction was
simply used to add revokes, since these are never written outside of the
journal, and thus, don't need an active items list.

Also, in order to make sure that the transaction structure is not
removed while it's still in use by gfs2_trans_end, unlocking the
sd_log_flush_lock has to happen slightly later in ending the
transaction.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-04-08 08:46:22 +01:00

308 lines
8.1 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/kallsyms.h>
#include <linux/gfs2_ondisk.h>
#include "gfs2.h"
#include "incore.h"
#include "glock.h"
#include "inode.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "trans.h"
#include "util.h"
#include "trace_gfs2.h"
int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
unsigned int revokes)
{
struct gfs2_trans *tr;
int error;
BUG_ON(current->journal_info);
BUG_ON(blocks == 0 && revokes == 0);
if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
return -EROFS;
tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);
if (!tr)
return -ENOMEM;
tr->tr_ip = (unsigned long)__builtin_return_address(0);
tr->tr_blocks = blocks;
tr->tr_revokes = revokes;
tr->tr_reserved = 1;
if (blocks)
tr->tr_reserved += 6 + blocks;
if (revokes)
tr->tr_reserved += gfs2_struct2blk(sdp, revokes,
sizeof(u64));
sb_start_intwrite(sdp->sd_vfs);
gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &tr->tr_t_gh);
error = gfs2_glock_nq(&tr->tr_t_gh);
if (error)
goto fail_holder_uninit;
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:
sb_end_intwrite(sdp->sd_vfs);
gfs2_holder_uninit(&tr->tr_t_gh);
kfree(tr);
return error;
}
/**
* gfs2_log_release - Release a given number of log blocks
* @sdp: The GFS2 superblock
* @blks: The number of blocks
*
*/
static void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
{
atomic_add(blks, &sdp->sd_log_blks_free);
trace_gfs2_log_blocks(sdp, blks);
gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
sdp->sd_jdesc->jd_blocks);
up_read(&sdp->sd_log_flush_lock);
}
static void gfs2_print_trans(const struct gfs2_trans *tr)
{
print_symbol(KERN_WARNING "GFS2: Transaction created at: %s\n", tr->tr_ip);
printk(KERN_WARNING "GFS2: blocks=%u revokes=%u reserved=%u touched=%d\n",
tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
printk(KERN_WARNING "GFS2: Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
tr->tr_num_buf_new, tr->tr_num_buf_rm,
tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
tr->tr_num_revoke, tr->tr_num_revoke_rm);
}
void gfs2_trans_end(struct gfs2_sbd *sdp)
{
struct gfs2_trans *tr = current->journal_info;
s64 nbuf;
BUG_ON(!tr);
current->journal_info = NULL;
if (!tr->tr_touched) {
gfs2_log_release(sdp, tr->tr_reserved);
if (tr->tr_t_gh.gh_gl) {
gfs2_glock_dq(&tr->tr_t_gh);
gfs2_holder_uninit(&tr->tr_t_gh);
kfree(tr);
}
sb_end_intwrite(sdp->sd_vfs);
return;
}
nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
nbuf -= tr->tr_num_buf_rm;
nbuf -= tr->tr_num_databuf_rm;
if (gfs2_assert_withdraw(sdp, (nbuf <= tr->tr_blocks) &&
(tr->tr_num_revoke <= tr->tr_revokes)))
gfs2_print_trans(tr);
gfs2_log_commit(sdp, tr);
if (tr->tr_t_gh.gh_gl) {
gfs2_glock_dq(&tr->tr_t_gh);
gfs2_holder_uninit(&tr->tr_t_gh);
if (!tr->tr_attached)
kfree(tr);
}
up_read(&sdp->sd_log_flush_lock);
if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
gfs2_log_flush(sdp, NULL);
sb_end_intwrite(sdp->sd_vfs);
}
static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl,
struct buffer_head *bh,
const struct gfs2_log_operations *lops)
{
struct gfs2_bufdata *bd;
bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
bd->bd_bh = bh;
bd->bd_gl = gl;
bd->bd_ops = lops;
INIT_LIST_HEAD(&bd->bd_list);
bh->b_private = bd;
return bd;
}
/**
* gfs2_trans_add_data - Add a databuf to the transaction.
* @gl: The inode glock associated with the buffer
* @bh: The buffer to add
*
* This is used in two distinct cases:
* i) In ordered write mode
* We put the data buffer on a list so that we can ensure that its
* synced to disk at the right time
* ii) In journaled data mode
* We need to journal the data block in the same way as metadata in
* the functions above. The difference is that here we have a tag
* which is two __be64's being the block number (as per meta data)
* and a flag which says whether the data block needs escaping or
* not. This means we need a new log entry for each 251 or so data
* blocks, which isn't an enormous overhead but twice as much as
* for normal metadata blocks.
*/
void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
{
struct gfs2_trans *tr = current->journal_info;
struct gfs2_sbd *sdp = gl->gl_sbd;
struct address_space *mapping = bh->b_page->mapping;
struct gfs2_inode *ip = GFS2_I(mapping->host);
struct gfs2_bufdata *bd;
if (!gfs2_is_jdata(ip)) {
gfs2_ordered_add_inode(ip);
return;
}
lock_buffer(bh);
gfs2_log_lock(sdp);
bd = bh->b_private;
if (bd == NULL) {
gfs2_log_unlock(sdp);
unlock_buffer(bh);
if (bh->b_private == NULL)
bd = gfs2_alloc_bufdata(gl, bh, &gfs2_databuf_lops);
lock_buffer(bh);
gfs2_log_lock(sdp);
}
gfs2_assert(sdp, bd->bd_gl == gl);
tr->tr_touched = 1;
if (list_empty(&bd->bd_list)) {
set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
gfs2_pin(sdp, bd->bd_bh);
tr->tr_num_databuf_new++;
sdp->sd_log_num_databuf++;
list_add_tail(&bd->bd_list, &sdp->sd_log_le_databuf);
}
gfs2_log_unlock(sdp);
unlock_buffer(bh);
}
static void meta_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
{
struct gfs2_meta_header *mh;
struct gfs2_trans *tr;
tr = current->journal_info;
tr->tr_touched = 1;
if (!list_empty(&bd->bd_list))
return;
set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) {
printk(KERN_ERR
"Attempting to add uninitialised block to journal (inplace block=%lld)\n",
(unsigned long long)bd->bd_bh->b_blocknr);
BUG();
}
gfs2_pin(sdp, bd->bd_bh);
mh->__pad0 = cpu_to_be64(0);
mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
sdp->sd_log_num_buf++;
list_add(&bd->bd_list, &sdp->sd_log_le_buf);
tr->tr_num_buf_new++;
}
void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_bufdata *bd;
lock_buffer(bh);
gfs2_log_lock(sdp);
bd = bh->b_private;
if (bd == NULL) {
gfs2_log_unlock(sdp);
unlock_buffer(bh);
lock_page(bh->b_page);
if (bh->b_private == NULL)
bd = gfs2_alloc_bufdata(gl, bh, &gfs2_buf_lops);
unlock_page(bh->b_page);
lock_buffer(bh);
gfs2_log_lock(sdp);
}
gfs2_assert(sdp, bd->bd_gl == gl);
meta_lo_add(sdp, bd);
gfs2_log_unlock(sdp);
unlock_buffer(bh);
}
void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
{
struct gfs2_glock *gl = bd->bd_gl;
struct gfs2_trans *tr = current->journal_info;
BUG_ON(!list_empty(&bd->bd_list));
BUG_ON(!list_empty(&bd->bd_ail_st_list));
BUG_ON(!list_empty(&bd->bd_ail_gl_list));
bd->bd_ops = &gfs2_revoke_lops;
tr->tr_touched = 1;
tr->tr_num_revoke++;
sdp->sd_log_num_revoke++;
atomic_inc(&gl->gl_revokes);
set_bit(GLF_LFLUSH, &gl->gl_flags);
list_add(&bd->bd_list, &sdp->sd_log_le_revoke);
}
void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
{
struct gfs2_bufdata *bd, *tmp;
struct gfs2_trans *tr = current->journal_info;
unsigned int n = len;
gfs2_log_lock(sdp);
list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_list) {
if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
list_del_init(&bd->bd_list);
gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
sdp->sd_log_num_revoke--;
kmem_cache_free(gfs2_bufdata_cachep, bd);
tr->tr_num_revoke_rm++;
if (--n == 0)
break;
}
}
gfs2_log_unlock(sdp);
}