linux/fs/gfs2/log.c
Steven Whitehouse 7359a19cc7 [GFS2] Fix for root inode ref count bug
Umount is now working correctly again. The bug was due to
not getting an extra ref count when mounting the fs. We
should have bumped it by two (once for the internal pointer
to the root inode from the super block and once for the
inode hanging off the dcache entry for root).

Also this patch tidys up the code dealing with looking up
and creating inodes. We now pass Linux inodes (with gfs2_inodes
attached) rather than the other way around and this reduces code
duplication in various places.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-02-13 12:27:43 +00:00

660 lines
16 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 <asm/semaphore.h>
#include "gfs2.h"
#include "bmap.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#define PULL 1
static inline int is_done(struct gfs2_sbd *sdp, atomic_t *a)
{
int done;
gfs2_log_lock(sdp);
done = atomic_read(a) ? 0 : 1;
gfs2_log_unlock(sdp);
return done;
}
static void do_lock_wait(struct gfs2_sbd *sdp, wait_queue_head_t *wq,
atomic_t *a)
{
gfs2_log_unlock(sdp);
wait_event(*wq, is_done(sdp, a));
gfs2_log_lock(sdp);
}
static void lock_for_trans(struct gfs2_sbd *sdp)
{
gfs2_log_lock(sdp);
do_lock_wait(sdp, &sdp->sd_log_trans_wq, &sdp->sd_log_flush_count);
atomic_inc(&sdp->sd_log_trans_count);
gfs2_log_unlock(sdp);
}
static void unlock_from_trans(struct gfs2_sbd *sdp)
{
gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_trans_count));
if (atomic_dec_and_test(&sdp->sd_log_trans_count))
wake_up(&sdp->sd_log_flush_wq);
}
void gfs2_lock_for_flush(struct gfs2_sbd *sdp)
{
gfs2_log_lock(sdp);
atomic_inc(&sdp->sd_log_flush_count);
do_lock_wait(sdp, &sdp->sd_log_flush_wq, &sdp->sd_log_trans_count);
gfs2_log_unlock(sdp);
}
void gfs2_unlock_from_flush(struct gfs2_sbd *sdp)
{
gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_flush_count));
if (atomic_dec_and_test(&sdp->sd_log_flush_count))
wake_up(&sdp->sd_log_trans_wq);
}
/**
* gfs2_struct2blk - compute stuff
* @sdp: the filesystem
* @nstruct: the number of structures
* @ssize: the size of the structures
*
* Compute the number of log descriptor blocks needed to hold a certain number
* of structures of a certain size.
*
* Returns: the number of blocks needed (minimum is always 1)
*/
unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
unsigned int ssize)
{
unsigned int blks;
unsigned int first, second;
blks = 1;
first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
if (nstruct > first) {
second = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / ssize;
blks += DIV_RU(nstruct - first, second);
}
return blks;
}
void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
{
struct list_head *head = &sdp->sd_ail1_list;
uint64_t sync_gen;
struct list_head *first, *tmp;
struct gfs2_ail *first_ai, *ai;
gfs2_log_lock(sdp);
if (list_empty(head)) {
gfs2_log_unlock(sdp);
return;
}
sync_gen = sdp->sd_ail_sync_gen++;
first = head->prev;
first_ai = list_entry(first, struct gfs2_ail, ai_list);
first_ai->ai_sync_gen = sync_gen;
gfs2_ail1_start_one(sdp, first_ai);
if (flags & DIO_ALL)
first = NULL;
for (;;) {
if (first &&
(head->prev != first ||
gfs2_ail1_empty_one(sdp, first_ai, 0)))
break;
for (tmp = head->prev; tmp != head; tmp = tmp->prev) {
ai = list_entry(tmp, struct gfs2_ail, ai_list);
if (ai->ai_sync_gen >= sync_gen)
continue;
ai->ai_sync_gen = sync_gen;
gfs2_ail1_start_one(sdp, ai);
break;
}
if (tmp == head)
break;
}
gfs2_log_unlock(sdp);
}
int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
{
struct gfs2_ail *ai, *s;
int ret;
gfs2_log_lock(sdp);
list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
if (gfs2_ail1_empty_one(sdp, ai, flags))
list_move(&ai->ai_list, &sdp->sd_ail2_list);
else if (!(flags & DIO_ALL))
break;
}
ret = list_empty(&sdp->sd_ail1_list);
gfs2_log_unlock(sdp);
return ret;
}
static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
{
struct gfs2_ail *ai, *safe;
unsigned int old_tail = sdp->sd_log_tail;
int wrap = (new_tail < old_tail);
int a, b, rm;
gfs2_log_lock(sdp);
list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
a = (old_tail <= ai->ai_first);
b = (ai->ai_first < new_tail);
rm = (wrap) ? (a || b) : (a && b);
if (!rm)
continue;
gfs2_ail2_empty_one(sdp, ai);
list_del(&ai->ai_list);
gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
kfree(ai);
}
gfs2_log_unlock(sdp);
}
/**
* gfs2_log_reserve - Make a log reservation
* @sdp: The GFS2 superblock
* @blks: The number of blocks to reserve
*
* Returns: errno
*/
int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
{
LIST_HEAD(list);
unsigned int try = 0;
if (gfs2_assert_warn(sdp, blks) ||
gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
return -EINVAL;
for (;;) {
gfs2_log_lock(sdp);
if (list_empty(&list)) {
list_add_tail(&list, &sdp->sd_log_blks_list);
while (sdp->sd_log_blks_list.next != &list) {
DECLARE_WAITQUEUE(__wait_chan, current);
set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&sdp->sd_log_blks_wait,
&__wait_chan);
gfs2_log_unlock(sdp);
schedule();
gfs2_log_lock(sdp);
remove_wait_queue(&sdp->sd_log_blks_wait,
&__wait_chan);
set_current_state(TASK_RUNNING);
}
}
/* Never give away the last block so we can
always pull the tail if we need to. */
if (sdp->sd_log_blks_free > blks) {
sdp->sd_log_blks_free -= blks;
list_del(&list);
gfs2_log_unlock(sdp);
wake_up(&sdp->sd_log_blks_wait);
break;
}
gfs2_log_unlock(sdp);
gfs2_ail1_empty(sdp, 0);
gfs2_log_flush(sdp);
if (try++)
gfs2_ail1_start(sdp, 0);
}
lock_for_trans(sdp);
return 0;
}
/**
* gfs2_log_release - Release a given number of log blocks
* @sdp: The GFS2 superblock
* @blks: The number of blocks
*
*/
void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
{
unlock_from_trans(sdp);
gfs2_log_lock(sdp);
sdp->sd_log_blks_free += blks;
gfs2_assert_withdraw(sdp,
sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
gfs2_log_unlock(sdp);
}
static uint64_t log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
{
int new = 0;
uint64_t dbn;
int error;
error = gfs2_block_map(get_v2ip(sdp->sd_jdesc->jd_inode), lbn, &new, &dbn, NULL);
gfs2_assert_withdraw(sdp, !error && dbn);
return dbn;
}
/**
* log_distance - Compute distance between two journal blocks
* @sdp: The GFS2 superblock
* @newer: The most recent journal block of the pair
* @older: The older journal block of the pair
*
* Compute the distance (in the journal direction) between two
* blocks in the journal
*
* Returns: the distance in blocks
*/
static inline unsigned int log_distance(struct gfs2_sbd *sdp,
unsigned int newer,
unsigned int older)
{
int dist;
dist = newer - older;
if (dist < 0)
dist += sdp->sd_jdesc->jd_blocks;
return dist;
}
static unsigned int current_tail(struct gfs2_sbd *sdp)
{
struct gfs2_ail *ai;
unsigned int tail;
gfs2_log_lock(sdp);
if (list_empty(&sdp->sd_ail1_list))
tail = sdp->sd_log_head;
else {
ai = list_entry(sdp->sd_ail1_list.prev,
struct gfs2_ail, ai_list);
tail = ai->ai_first;
}
gfs2_log_unlock(sdp);
return tail;
}
static inline void log_incr_head(struct gfs2_sbd *sdp)
{
if (sdp->sd_log_flush_head == sdp->sd_log_tail)
gfs2_assert_withdraw(sdp,
sdp->sd_log_flush_head == sdp->sd_log_head);
if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
sdp->sd_log_flush_head = 0;
sdp->sd_log_flush_wrapped = 1;
}
}
/**
* gfs2_log_get_buf - Get and initialize a buffer to use for log control data
* @sdp: The GFS2 superblock
*
* Returns: the buffer_head
*/
struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
{
uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
struct gfs2_log_buf *lb;
struct buffer_head *bh;
lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
list_add(&lb->lb_list, &sdp->sd_log_flush_list);
bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
lock_buffer(bh);
memset(bh->b_data, 0, bh->b_size);
set_buffer_uptodate(bh);
clear_buffer_dirty(bh);
unlock_buffer(bh);
log_incr_head(sdp);
return bh;
}
/**
* gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
* @sdp: the filesystem
* @data: the data the buffer_head should point to
*
* Returns: the log buffer descriptor
*/
struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
struct buffer_head *real)
{
uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
struct gfs2_log_buf *lb;
struct buffer_head *bh;
lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
list_add(&lb->lb_list, &sdp->sd_log_flush_list);
lb->lb_real = real;
bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
atomic_set(&bh->b_count, 1);
bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
set_bh_page(bh, real->b_page, bh_offset(real));
bh->b_blocknr = blkno;
bh->b_size = sdp->sd_sb.sb_bsize;
bh->b_bdev = sdp->sd_vfs->s_bdev;
log_incr_head(sdp);
return bh;
}
static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull)
{
unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
ail2_empty(sdp, new_tail);
gfs2_log_lock(sdp);
sdp->sd_log_blks_free += dist - ((pull) ? 1 : 0);
gfs2_assert_withdraw(sdp,
sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
gfs2_log_unlock(sdp);
sdp->sd_log_tail = new_tail;
}
/**
* log_write_header - Get and initialize a journal header buffer
* @sdp: The GFS2 superblock
*
* Returns: the initialized log buffer descriptor
*/
static void log_write_header(struct gfs2_sbd *sdp, uint32_t flags, int pull)
{
uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
struct buffer_head *bh;
struct gfs2_log_header *lh;
unsigned int tail;
uint32_t hash;
atomic_inc(&sdp->sd_log_flush_ondisk);
bh = sb_getblk(sdp->sd_vfs, blkno);
lock_buffer(bh);
memset(bh->b_data, 0, bh->b_size);
set_buffer_uptodate(bh);
clear_buffer_dirty(bh);
unlock_buffer(bh);
gfs2_ail1_empty(sdp, 0);
tail = current_tail(sdp);
lh = (struct gfs2_log_header *)bh->b_data;
memset(lh, 0, sizeof(struct gfs2_log_header));
lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
lh->lh_header.mh_type = cpu_to_be16(GFS2_METATYPE_LH);
lh->lh_header.mh_format = cpu_to_be16(GFS2_FORMAT_LH);
lh->lh_sequence = be64_to_cpu(sdp->sd_log_sequence++);
lh->lh_flags = be32_to_cpu(flags);
lh->lh_tail = be32_to_cpu(tail);
lh->lh_blkno = be32_to_cpu(sdp->sd_log_flush_head);
hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
lh->lh_hash = cpu_to_be32(hash);
set_buffer_dirty(bh);
if (sync_dirty_buffer(bh))
gfs2_io_error_bh(sdp, bh);
brelse(bh);
if (sdp->sd_log_tail != tail)
log_pull_tail(sdp, tail, pull);
else
gfs2_assert_withdraw(sdp, !pull);
sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
log_incr_head(sdp);
}
static void log_flush_commit(struct gfs2_sbd *sdp)
{
struct list_head *head = &sdp->sd_log_flush_list;
struct gfs2_log_buf *lb;
struct buffer_head *bh;
unsigned int d;
d = log_distance(sdp, sdp->sd_log_flush_head, sdp->sd_log_head);
gfs2_assert_withdraw(sdp, d + 1 == sdp->sd_log_blks_reserved);
while (!list_empty(head)) {
lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
list_del(&lb->lb_list);
bh = lb->lb_bh;
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
if (lb->lb_real) {
while (atomic_read(&bh->b_count) != 1) /* Grrrr... */
schedule();
free_buffer_head(bh);
} else
brelse(bh);
kfree(lb);
}
log_write_header(sdp, 0, 0);
}
/**
* gfs2_log_flush_i - flush incore transaction(s)
* @sdp: the filesystem
* @gl: The glock structure to flush. If NULL, flush the whole incore log
*
*/
void gfs2_log_flush_i(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
{
struct gfs2_ail *ai;
atomic_inc(&sdp->sd_log_flush_incore);
ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
INIT_LIST_HEAD(&ai->ai_ail1_list);
INIT_LIST_HEAD(&ai->ai_ail2_list);
gfs2_lock_for_flush(sdp);
down(&sdp->sd_log_flush_lock);
gfs2_assert_withdraw(sdp,
sdp->sd_log_num_buf == sdp->sd_log_commited_buf);
gfs2_assert_withdraw(sdp,
sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
if (gl && list_empty(&gl->gl_le.le_list)) {
up(&sdp->sd_log_flush_lock);
gfs2_unlock_from_flush(sdp);
kfree(ai);
return;
}
sdp->sd_log_flush_head = sdp->sd_log_head;
sdp->sd_log_flush_wrapped = 0;
ai->ai_first = sdp->sd_log_flush_head;
lops_before_commit(sdp);
if (!list_empty(&sdp->sd_log_flush_list))
log_flush_commit(sdp);
else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle)
log_write_header(sdp, 0, PULL);
lops_after_commit(sdp, ai);
sdp->sd_log_head = sdp->sd_log_flush_head;
if (sdp->sd_log_flush_wrapped)
sdp->sd_log_wraps++;
sdp->sd_log_blks_reserved =
sdp->sd_log_commited_buf =
sdp->sd_log_commited_revoke = 0;
gfs2_log_lock(sdp);
if (!list_empty(&ai->ai_ail1_list)) {
list_add(&ai->ai_list, &sdp->sd_ail1_list);
ai = NULL;
}
gfs2_log_unlock(sdp);
up(&sdp->sd_log_flush_lock);
sdp->sd_vfs->s_dirt = 0;
gfs2_unlock_from_flush(sdp);
kfree(ai);
}
static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
unsigned int reserved = 1;
unsigned int old;
gfs2_log_lock(sdp);
sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0);
sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
if (sdp->sd_log_commited_buf)
reserved += 1 + sdp->sd_log_commited_buf + sdp->sd_log_commited_buf/503;
if (sdp->sd_log_commited_revoke)
reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
sizeof(uint64_t));
old = sdp->sd_log_blks_free;
sdp->sd_log_blks_free += tr->tr_reserved -
(reserved - sdp->sd_log_blks_reserved);
gfs2_assert_withdraw(sdp,
sdp->sd_log_blks_free >= old);
gfs2_assert_withdraw(sdp,
sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
sdp->sd_log_blks_reserved = reserved;
gfs2_log_unlock(sdp);
}
/**
* gfs2_log_commit - Commit a transaction to the log
* @sdp: the filesystem
* @tr: the transaction
*
* Returns: errno
*/
void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
log_refund(sdp, tr);
lops_incore_commit(sdp, tr);
sdp->sd_vfs->s_dirt = 1;
unlock_from_trans(sdp);
kfree(tr);
gfs2_log_lock(sdp);
if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) {
gfs2_log_unlock(sdp);
gfs2_log_flush(sdp);
} else
gfs2_log_unlock(sdp);
}
/**
* gfs2_log_shutdown - write a shutdown header into a journal
* @sdp: the filesystem
*
*/
void gfs2_log_shutdown(struct gfs2_sbd *sdp)
{
down(&sdp->sd_log_flush_lock);
gfs2_assert_withdraw(sdp, !atomic_read(&sdp->sd_log_trans_count));
gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
sdp->sd_log_flush_head = sdp->sd_log_head;
sdp->sd_log_flush_wrapped = 0;
log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0);
gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free ==
sdp->sd_jdesc->jd_blocks);
gfs2_assert_withdraw(sdp, sdp->sd_log_head == sdp->sd_log_tail);
gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail2_list));
sdp->sd_log_head = sdp->sd_log_flush_head;
if (sdp->sd_log_flush_wrapped)
sdp->sd_log_wraps++;
sdp->sd_log_tail = sdp->sd_log_head;
up(&sdp->sd_log_flush_lock);
}