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linux/fs/gfs2/log.c
Steven Whitehouse 254db57f9b GFS2: Support for I/O barriers 
This patch adds barrier support to GFS2. There is not a lot of change
really... we just add the barrier flag when we write journal header
blocks. If the underlying device refuses to support them, we fall back
to the previous way of doing things (wait for the I/O and hope) since
there is nothing else we can do. There is no user configuration,
barriers will always be on unless the device refuses to support them.
This seems a reasonable solution to me since this is a correctness
issue.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-09-26 10:23:22 +01:00

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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2007 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/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/bio.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "util.h"
#include "dir.h"
#define PULL 1
/**
* 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_ROUND_UP(nstruct - first, second);
}
return blks;
}
/**
* gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
* @mapping: The associated mapping (maybe NULL)
* @bd: The gfs2_bufdata to remove
*
* The log lock _must_ be held when calling this function
*
*/
void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
{
bd->bd_ail = NULL;
list_del_init(&bd->bd_ail_st_list);
list_del_init(&bd->bd_ail_gl_list);
atomic_dec(&bd->bd_gl->gl_ail_count);
brelse(bd->bd_bh);
}
/**
* gfs2_ail1_start_one - Start I/O on a part of the AIL
* @sdp: the filesystem
* @tr: the part of the AIL
*
*/
static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
__releases(&sdp->sd_log_lock)
__acquires(&sdp->sd_log_lock)
{
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
int retry;
do {
retry = 0;
list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
bd_ail_st_list) {
bh = bd->bd_bh;
gfs2_assert(sdp, bd->bd_ail == ai);
if (!buffer_busy(bh)) {
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
continue;
}
if (!buffer_dirty(bh))
continue;
list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
get_bh(bh);
gfs2_log_unlock(sdp);
lock_buffer(bh);
if (test_clear_buffer_dirty(bh)) {
bh->b_end_io = end_buffer_write_sync;
submit_bh(WRITE, bh);
} else {
unlock_buffer(bh);
brelse(bh);
}
gfs2_log_lock(sdp);
retry = 1;
break;
}
} while (retry);
}
/**
* gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
* @sdp: the filesystem
* @ai: the AIL entry
*
*/
static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
{
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
bd_ail_st_list) {
bh = bd->bd_bh;
gfs2_assert(sdp, bd->bd_ail == ai);
if (buffer_busy(bh)) {
if (flags & DIO_ALL)
continue;
else
break;
}
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
}
return list_empty(&ai->ai_ail1_list);
}
static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
{
struct list_head *head;
u64 sync_gen;
struct list_head *first;
struct gfs2_ail *first_ai, *ai, *tmp;
int done = 0;
gfs2_log_lock(sdp);
head = &sdp->sd_ail1_list;
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); /* This may drop log lock */
if (flags & DIO_ALL)
first = NULL;
while(!done) {
if (first && (head->prev != first ||
gfs2_ail1_empty_one(sdp, first_ai, 0)))
break;
done = 1;
list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
if (ai->ai_sync_gen >= sync_gen)
continue;
ai->ai_sync_gen = sync_gen;
gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
done = 0;
break;
}
}
gfs2_log_unlock(sdp);
}
static 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;
}
/**
* gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
* @sdp: the filesystem
* @ai: the AIL entry
*
*/
static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
struct list_head *head = &ai->ai_ail2_list;
struct gfs2_bufdata *bd;
while (!list_empty(head)) {
bd = list_entry(head->prev, struct gfs2_bufdata,
bd_ail_st_list);
gfs2_assert(sdp, bd->bd_ail == ai);
gfs2_remove_from_ail(bd);
}
}
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
*
* Note that we never give out the last few blocks of the journal. Thats
* due to the fact that there is a small number of header blocks
* associated with each log flush. The exact number can't be known until
* flush time, so we ensure that we have just enough free blocks at all
* times to avoid running out during a log flush.
*
* Returns: errno
*/
int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
{
unsigned int try = 0;
unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
if (gfs2_assert_warn(sdp, blks) ||
gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
return -EINVAL;
mutex_lock(&sdp->sd_log_reserve_mutex);
gfs2_log_lock(sdp);
while(atomic_read(&sdp->sd_log_blks_free) <= (blks + reserved_blks)) {
gfs2_log_unlock(sdp);
gfs2_ail1_empty(sdp, 0);
gfs2_log_flush(sdp, NULL);
if (try++)
gfs2_ail1_start(sdp, 0);
gfs2_log_lock(sdp);
}
atomic_sub(blks, &sdp->sd_log_blks_free);
gfs2_log_unlock(sdp);
mutex_unlock(&sdp->sd_log_reserve_mutex);
down_read(&sdp->sd_log_flush_lock);
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)
{
gfs2_log_lock(sdp);
atomic_add(blks, &sdp->sd_log_blks_free);
gfs2_assert_withdraw(sdp,
atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks);
gfs2_log_unlock(sdp);
up_read(&sdp->sd_log_flush_lock);
}
static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
{
struct gfs2_journal_extent *je;
list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) {
if (lbn >= je->lblock && lbn < je->lblock + je->blocks)
return je->dblock + lbn - je->lblock;
}
return -1;
}
/**
* 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;
}
/**
* calc_reserved - Calculate the number of blocks to reserve when
* refunding a transaction's unused buffers.
* @sdp: The GFS2 superblock
*
* This is complex. We need to reserve room for all our currently used
* metadata buffers (e.g. normal file I/O rewriting file time stamps) and
* all our journaled data buffers for journaled files (e.g. files in the
* meta_fs like rindex, or files for which chattr +j was done.)
* If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
* will count it as free space (sd_log_blks_free) and corruption will follow.
*
* We can have metadata bufs and jdata bufs in the same journal. So each
* type gets its own log header, for which we need to reserve a block.
* In fact, each type has the potential for needing more than one header
* in cases where we have more buffers than will fit on a journal page.
* Metadata journal entries take up half the space of journaled buffer entries.
* Thus, metadata entries have buf_limit (502) and journaled buffers have
* databuf_limit (251) before they cause a wrap around.
*
* Also, we need to reserve blocks for revoke journal entries and one for an
* overall header for the lot.
*
* Returns: the number of blocks reserved
*/
static unsigned int calc_reserved(struct gfs2_sbd *sdp)
{
unsigned int reserved = 0;
unsigned int mbuf_limit, metabufhdrs_needed;
unsigned int dbuf_limit, databufhdrs_needed;
unsigned int revokes = 0;
mbuf_limit = buf_limit(sdp);
metabufhdrs_needed = (sdp->sd_log_commited_buf +
(mbuf_limit - 1)) / mbuf_limit;
dbuf_limit = databuf_limit(sdp);
databufhdrs_needed = (sdp->sd_log_commited_databuf +
(dbuf_limit - 1)) / dbuf_limit;
if (sdp->sd_log_commited_revoke)
revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
sizeof(u64));
reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
sdp->sd_log_commited_databuf + databufhdrs_needed +
revokes;
/* One for the overall header */
if (reserved)
reserved++;
return reserved;
}
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;
}
void gfs2_log_incr_head(struct gfs2_sbd *sdp)
{
if (sdp->sd_log_flush_head == sdp->sd_log_tail)
BUG_ON(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_write_endio - End of I/O for a log buffer
* @bh: The buffer head
* @uptodate: I/O Status
*
*/
static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
{
struct gfs2_sbd *sdp = bh->b_private;
bh->b_private = NULL;
end_buffer_write_sync(bh, uptodate);
if (atomic_dec_and_test(&sdp->sd_log_in_flight))
wake_up(&sdp->sd_log_flush_wait);
}
/**
* 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)
{
u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
struct buffer_head *bh;
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);
gfs2_log_incr_head(sdp);
atomic_inc(&sdp->sd_log_in_flight);
bh->b_private = sdp;
bh->b_end_io = gfs2_log_write_endio;
return bh;
}
/**
* gfs2_fake_write_endio -
* @bh: The buffer head
* @uptodate: The I/O Status
*
*/
static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
{
struct buffer_head *real_bh = bh->b_private;
struct gfs2_bufdata *bd = real_bh->b_private;
struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
end_buffer_write_sync(bh, uptodate);
free_buffer_head(bh);
unlock_buffer(real_bh);
brelse(real_bh);
if (atomic_dec_and_test(&sdp->sd_log_in_flight))
wake_up(&sdp->sd_log_flush_wait);
}
/**
* 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)
{
u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
struct buffer_head *bh;
bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
atomic_set(&bh->b_count, 1);
bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
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;
bh->b_private = real;
bh->b_end_io = gfs2_fake_write_endio;
gfs2_log_incr_head(sdp);
atomic_inc(&sdp->sd_log_in_flight);
return bh;
}
static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
{
unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
ail2_empty(sdp, new_tail);
gfs2_log_lock(sdp);
atomic_add(dist, &sdp->sd_log_blks_free);
gfs2_assert_withdraw(sdp, atomic_read(&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, u32 flags, int pull)
{
u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
struct buffer_head *bh;
struct gfs2_log_header *lh;
unsigned int tail;
u32 hash;
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);
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_be32(GFS2_METATYPE_LH);
lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
lh->lh_flags = cpu_to_be32(flags);
lh->lh_tail = cpu_to_be32(tail);
lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
lh->lh_hash = cpu_to_be32(hash);
bh->b_end_io = end_buffer_write_sync;
if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
goto skip_barrier;
get_bh(bh);
submit_bh(WRITE_BARRIER | (1 << BIO_RW_META), bh);
wait_on_buffer(bh);
if (buffer_eopnotsupp(bh)) {
clear_buffer_eopnotsupp(bh);
set_buffer_uptodate(bh);
set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
lock_buffer(bh);
skip_barrier:
get_bh(bh);
submit_bh(WRITE_SYNC | (1 << BIO_RW_META), bh);
wait_on_buffer(bh);
}
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
brelse(bh);
if (sdp->sd_log_tail != tail)
log_pull_tail(sdp, tail);
else
gfs2_assert_withdraw(sdp, !pull);
sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
gfs2_log_incr_head(sdp);
}
static void log_flush_commit(struct gfs2_sbd *sdp)
{
DEFINE_WAIT(wait);
if (atomic_read(&sdp->sd_log_in_flight)) {
do {
prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (atomic_read(&sdp->sd_log_in_flight))
io_schedule();
} while(atomic_read(&sdp->sd_log_in_flight));
finish_wait(&sdp->sd_log_flush_wait, &wait);
}
log_write_header(sdp, 0, 0);
}
static void gfs2_ordered_write(struct gfs2_sbd *sdp)
{
struct gfs2_bufdata *bd;
struct buffer_head *bh;
LIST_HEAD(written);
gfs2_log_lock(sdp);
while (!list_empty(&sdp->sd_log_le_ordered)) {
bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
list_move(&bd->bd_le.le_list, &written);
bh = bd->bd_bh;
if (!buffer_dirty(bh))
continue;
get_bh(bh);
gfs2_log_unlock(sdp);
lock_buffer(bh);
if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
bh->b_end_io = end_buffer_write_sync;
submit_bh(WRITE, bh);
} else {
unlock_buffer(bh);
brelse(bh);
}
gfs2_log_lock(sdp);
}
list_splice(&written, &sdp->sd_log_le_ordered);
gfs2_log_unlock(sdp);
}
static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
{
struct gfs2_bufdata *bd;
struct buffer_head *bh;
gfs2_log_lock(sdp);
while (!list_empty(&sdp->sd_log_le_ordered)) {
bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
bh = bd->bd_bh;
if (buffer_locked(bh)) {
get_bh(bh);
gfs2_log_unlock(sdp);
wait_on_buffer(bh);
brelse(bh);
gfs2_log_lock(sdp);
continue;
}
list_del_init(&bd->bd_le.le_list);
}
gfs2_log_unlock(sdp);
}
/**
* gfs2_log_flush - flush incore transaction(s)
* @sdp: the filesystem
* @gl: The glock structure to flush. If NULL, flush the whole incore log
*
*/
void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
{
struct gfs2_ail *ai;
down_write(&sdp->sd_log_flush_lock);
/* Log might have been flushed while we waited for the flush lock */
if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
up_write(&sdp->sd_log_flush_lock);
return;
}
ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
INIT_LIST_HEAD(&ai->ai_ail1_list);
INIT_LIST_HEAD(&ai->ai_ail2_list);
if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
sdp->sd_log_commited_buf);
gfs2_assert_withdraw(sdp, 0);
}
if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
printk(KERN_INFO "GFS2: log databuf %u %u\n",
sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
gfs2_assert_withdraw(sdp, 0);
}
gfs2_assert_withdraw(sdp,
sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
sdp->sd_log_flush_head = sdp->sd_log_head;
sdp->sd_log_flush_wrapped = 0;
ai->ai_first = sdp->sd_log_flush_head;
gfs2_ordered_write(sdp);
lops_before_commit(sdp);
gfs2_ordered_wait(sdp);
if (sdp->sd_log_head != sdp->sd_log_flush_head)
log_flush_commit(sdp);
else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
gfs2_log_lock(sdp);
atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
gfs2_log_unlock(sdp);
log_write_header(sdp, 0, PULL);
}
lops_after_commit(sdp, ai);
gfs2_log_lock(sdp);
sdp->sd_log_head = sdp->sd_log_flush_head;
sdp->sd_log_blks_reserved = 0;
sdp->sd_log_commited_buf = 0;
sdp->sd_log_commited_databuf = 0;
sdp->sd_log_commited_revoke = 0;
if (!list_empty(&ai->ai_ail1_list)) {
list_add(&ai->ai_list, &sdp->sd_ail1_list);
ai = NULL;
}
gfs2_log_unlock(sdp);
sdp->sd_vfs->s_dirt = 0;
up_write(&sdp->sd_log_flush_lock);
kfree(ai);
}
static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
unsigned int reserved;
unsigned int unused;
gfs2_log_lock(sdp);
sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
tr->tr_num_databuf_rm;
gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
(((int)sdp->sd_log_commited_databuf) >= 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);
reserved = calc_reserved(sdp);
gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
atomic_add(unused, &sdp->sd_log_blks_free);
gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
sdp->sd_jdesc->jd_blocks);
sdp->sd_log_blks_reserved = reserved;
gfs2_log_unlock(sdp);
}
static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
struct list_head *head = &tr->tr_list_buf;
struct gfs2_bufdata *bd;
gfs2_log_lock(sdp);
while (!list_empty(head)) {
bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
list_del_init(&bd->bd_list_tr);
tr->tr_num_buf--;
}
gfs2_log_unlock(sdp);
gfs2_assert_warn(sdp, !tr->tr_num_buf);
}
/**
* 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);
buf_lo_incore_commit(sdp, tr);
sdp->sd_vfs->s_dirt = 1;
up_read(&sdp->sd_log_flush_lock);
gfs2_log_lock(sdp);
if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
wake_up_process(sdp->sd_logd_process);
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_write(&sdp->sd_log_flush_lock);
gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
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,
(sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
sdp->sd_log_head = sdp->sd_log_flush_head;
sdp->sd_log_tail = sdp->sd_log_head;
up_write(&sdp->sd_log_flush_lock);
}
/**
* gfs2_meta_syncfs - sync all the buffers in a filesystem
* @sdp: the filesystem
*
*/
void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
{
gfs2_log_flush(sdp, NULL);
for (;;) {
gfs2_ail1_start(sdp, DIO_ALL);
if (gfs2_ail1_empty(sdp, DIO_ALL))
break;
msleep(10);
}
}
/**
* gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
* @sdp: Pointer to GFS2 superblock
*
* Also, periodically check to make sure that we're using the most recent
* journal index.
*/
int gfs2_logd(void *data)
{
struct gfs2_sbd *sdp = data;
unsigned long t;
int need_flush;
while (!kthread_should_stop()) {
/* Advance the log tail */
t = sdp->sd_log_flush_time +
gfs2_tune_get(sdp, gt_log_flush_secs) * HZ;
gfs2_ail1_empty(sdp, DIO_ALL);
gfs2_log_lock(sdp);
need_flush = sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks);
gfs2_log_unlock(sdp);
if (need_flush || time_after_eq(jiffies, t)) {
gfs2_log_flush(sdp, NULL);
sdp->sd_log_flush_time = jiffies;
}
t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
if (freezing(current))
refrigerator();
schedule_timeout_interruptible(t);
}
return 0;
}
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