linux-sg2042/fs/gfs2/unlinked.c

454 lines
9.5 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/kthread.h>
#include <asm/semaphore.h>
#include "gfs2.h"
#include "bmap.h"
#include "inode.h"
#include "meta_io.h"
#include "trans.h"
#include "unlinked.h"
static int munge_ondisk(struct gfs2_sbd *sdp, unsigned int slot,
struct gfs2_unlinked_tag *ut)
{
struct gfs2_inode *ip = get_v2ip(sdp->sd_ut_inode);
unsigned int block, offset;
uint64_t dblock;
int new = 0;
struct buffer_head *bh;
int error;
block = slot / sdp->sd_ut_per_block;
offset = slot % sdp->sd_ut_per_block;
error = gfs2_block_map(ip, block, &new, &dblock, NULL);
if (error)
return error;
error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, &bh);
if (error)
return error;
if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) {
error = -EIO;
goto out;
}
mutex_lock(&sdp->sd_unlinked_mutex);
gfs2_trans_add_bh(ip->i_gl, bh, 1);
gfs2_unlinked_tag_out(ut, bh->b_data +
sizeof(struct gfs2_meta_header) +
offset * sizeof(struct gfs2_unlinked_tag));
mutex_unlock(&sdp->sd_unlinked_mutex);
out:
brelse(bh);
return error;
}
static void ul_hash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
{
spin_lock(&sdp->sd_unlinked_spin);
list_add(&ul->ul_list, &sdp->sd_unlinked_list);
gfs2_assert(sdp, ul->ul_count);
ul->ul_count++;
atomic_inc(&sdp->sd_unlinked_count);
spin_unlock(&sdp->sd_unlinked_spin);
}
static void ul_unhash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
{
spin_lock(&sdp->sd_unlinked_spin);
list_del_init(&ul->ul_list);
gfs2_assert(sdp, ul->ul_count > 1);
ul->ul_count--;
gfs2_assert_warn(sdp, atomic_read(&sdp->sd_unlinked_count) > 0);
atomic_dec(&sdp->sd_unlinked_count);
spin_unlock(&sdp->sd_unlinked_spin);
}
static struct gfs2_unlinked *ul_fish(struct gfs2_sbd *sdp)
{
struct list_head *head;
struct gfs2_unlinked *ul;
int found = 0;
if (sdp->sd_vfs->s_flags & MS_RDONLY)
return NULL;
spin_lock(&sdp->sd_unlinked_spin);
head = &sdp->sd_unlinked_list;
list_for_each_entry(ul, head, ul_list) {
if (test_bit(ULF_LOCKED, &ul->ul_flags))
continue;
list_move_tail(&ul->ul_list, head);
ul->ul_count++;
set_bit(ULF_LOCKED, &ul->ul_flags);
found = 1;
break;
}
if (!found)
ul = NULL;
spin_unlock(&sdp->sd_unlinked_spin);
return ul;
}
/**
* enforce_limit - limit the number of inodes waiting to be deallocated
* @sdp: the filesystem
*
* Returns: errno
*/
static void enforce_limit(struct gfs2_sbd *sdp)
{
unsigned int tries = 0, min = 0;
int error;
if (atomic_read(&sdp->sd_unlinked_count) >=
gfs2_tune_get(sdp, gt_ilimit)) {
tries = gfs2_tune_get(sdp, gt_ilimit_tries);
min = gfs2_tune_get(sdp, gt_ilimit_min);
}
while (tries--) {
struct gfs2_unlinked *ul = ul_fish(sdp);
if (!ul)
break;
error = gfs2_inode_dealloc(sdp, ul);
gfs2_unlinked_put(sdp, ul);
if (!error) {
if (!--min)
break;
} else if (error != 1)
break;
}
}
static struct gfs2_unlinked *ul_alloc(struct gfs2_sbd *sdp)
{
struct gfs2_unlinked *ul;
ul = kzalloc(sizeof(struct gfs2_unlinked), GFP_KERNEL);
if (ul) {
INIT_LIST_HEAD(&ul->ul_list);
ul->ul_count = 1;
set_bit(ULF_LOCKED, &ul->ul_flags);
}
return ul;
}
int gfs2_unlinked_get(struct gfs2_sbd *sdp, struct gfs2_unlinked **ul)
{
unsigned int c, o = 0, b;
unsigned char byte = 0;
enforce_limit(sdp);
*ul = ul_alloc(sdp);
if (!*ul)
return -ENOMEM;
spin_lock(&sdp->sd_unlinked_spin);
for (c = 0; c < sdp->sd_unlinked_chunks; c++)
for (o = 0; o < PAGE_SIZE; o++) {
byte = sdp->sd_unlinked_bitmap[c][o];
if (byte != 0xFF)
goto found;
}
goto fail;
found:
for (b = 0; b < 8; b++)
if (!(byte & (1 << b)))
break;
(*ul)->ul_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
if ((*ul)->ul_slot >= sdp->sd_unlinked_slots)
goto fail;
sdp->sd_unlinked_bitmap[c][o] |= 1 << b;
spin_unlock(&sdp->sd_unlinked_spin);
return 0;
fail:
spin_unlock(&sdp->sd_unlinked_spin);
kfree(*ul);
return -ENOSPC;
}
void gfs2_unlinked_put(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
{
gfs2_assert_warn(sdp, test_and_clear_bit(ULF_LOCKED, &ul->ul_flags));
spin_lock(&sdp->sd_unlinked_spin);
gfs2_assert(sdp, ul->ul_count);
ul->ul_count--;
if (!ul->ul_count) {
gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, ul->ul_slot, 0);
spin_unlock(&sdp->sd_unlinked_spin);
kfree(ul);
} else
spin_unlock(&sdp->sd_unlinked_spin);
}
int gfs2_unlinked_ondisk_add(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
{
int error;
gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
gfs2_assert_warn(sdp, list_empty(&ul->ul_list));
error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut);
if (!error)
ul_hash(sdp, ul);
return error;
}
int gfs2_unlinked_ondisk_munge(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
{
int error;
gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
gfs2_assert_warn(sdp, !list_empty(&ul->ul_list));
error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut);
return error;
}
int gfs2_unlinked_ondisk_rm(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
{
struct gfs2_unlinked_tag ut;
int error;
gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
gfs2_assert_warn(sdp, !list_empty(&ul->ul_list));
memset(&ut, 0, sizeof(struct gfs2_unlinked_tag));
error = munge_ondisk(sdp, ul->ul_slot, &ut);
if (error)
return error;
ul_unhash(sdp, ul);
return 0;
}
/**
* gfs2_unlinked_dealloc - Go through the list of inodes to be deallocated
* @sdp: the filesystem
*
* Returns: errno
*/
int gfs2_unlinked_dealloc(struct gfs2_sbd *sdp)
{
unsigned int hits, strikes;
int error;
for (;;) {
hits = 0;
strikes = 0;
for (;;) {
struct gfs2_unlinked *ul = ul_fish(sdp);
if (!ul)
return 0;
error = gfs2_inode_dealloc(sdp, ul);
gfs2_unlinked_put(sdp, ul);
if (!error) {
hits++;
if (strikes)
strikes--;
} else if (error == 1) {
strikes++;
if (strikes >=
atomic_read(&sdp->sd_unlinked_count)) {
error = 0;
break;
}
} else
return error;
}
if (!hits || kthread_should_stop())
break;
cond_resched();
}
return 0;
}
int gfs2_unlinked_init(struct gfs2_sbd *sdp)
{
struct gfs2_inode *ip = get_v2ip(sdp->sd_ut_inode);
unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
unsigned int x, slot = 0;
unsigned int found = 0;
uint64_t dblock;
uint32_t extlen = 0;
int error;
if (!ip->i_di.di_size ||
ip->i_di.di_size > (64 << 20) ||
ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
gfs2_consist_inode(ip);
return -EIO;
}
sdp->sd_unlinked_slots = blocks * sdp->sd_ut_per_block;
sdp->sd_unlinked_chunks = DIV_RU(sdp->sd_unlinked_slots, 8 * PAGE_SIZE);
error = -ENOMEM;
sdp->sd_unlinked_bitmap = kcalloc(sdp->sd_unlinked_chunks,
sizeof(unsigned char *),
GFP_KERNEL);
if (!sdp->sd_unlinked_bitmap)
return error;
for (x = 0; x < sdp->sd_unlinked_chunks; x++) {
sdp->sd_unlinked_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!sdp->sd_unlinked_bitmap[x])
goto fail;
}
for (x = 0; x < blocks; x++) {
struct buffer_head *bh;
unsigned int y;
if (!extlen) {
int new = 0;
error = gfs2_block_map(ip, x, &new, &dblock, &extlen);
if (error)
goto fail;
}
gfs2_meta_ra(ip->i_gl, dblock, extlen);
error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT,
&bh);
if (error)
goto fail;
error = -EIO;
if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) {
brelse(bh);
goto fail;
}
for (y = 0;
y < sdp->sd_ut_per_block && slot < sdp->sd_unlinked_slots;
y++, slot++) {
struct gfs2_unlinked_tag ut;
struct gfs2_unlinked *ul;
gfs2_unlinked_tag_in(&ut, bh->b_data +
sizeof(struct gfs2_meta_header) +
y * sizeof(struct gfs2_unlinked_tag));
if (!ut.ut_inum.no_addr)
continue;
error = -ENOMEM;
ul = ul_alloc(sdp);
if (!ul) {
brelse(bh);
goto fail;
}
ul->ul_ut = ut;
ul->ul_slot = slot;
spin_lock(&sdp->sd_unlinked_spin);
gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, slot, 1);
spin_unlock(&sdp->sd_unlinked_spin);
ul_hash(sdp, ul);
gfs2_unlinked_put(sdp, ul);
found++;
}
brelse(bh);
dblock++;
extlen--;
}
if (found)
fs_info(sdp, "found %u unlinked inodes\n", found);
return 0;
fail:
gfs2_unlinked_cleanup(sdp);
return error;
}
/**
* gfs2_unlinked_cleanup - get rid of any extra struct gfs2_unlinked structures
* @sdp: the filesystem
*
*/
void gfs2_unlinked_cleanup(struct gfs2_sbd *sdp)
{
struct list_head *head = &sdp->sd_unlinked_list;
struct gfs2_unlinked *ul;
unsigned int x;
spin_lock(&sdp->sd_unlinked_spin);
while (!list_empty(head)) {
ul = list_entry(head->next, struct gfs2_unlinked, ul_list);
if (ul->ul_count > 1) {
list_move_tail(&ul->ul_list, head);
spin_unlock(&sdp->sd_unlinked_spin);
schedule();
spin_lock(&sdp->sd_unlinked_spin);
continue;
}
list_del_init(&ul->ul_list);
atomic_dec(&sdp->sd_unlinked_count);
gfs2_assert_warn(sdp, ul->ul_count == 1);
gfs2_assert_warn(sdp, !test_bit(ULF_LOCKED, &ul->ul_flags));
kfree(ul);
}
spin_unlock(&sdp->sd_unlinked_spin);
gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_unlinked_count));
if (sdp->sd_unlinked_bitmap) {
for (x = 0; x < sdp->sd_unlinked_chunks; x++)
kfree(sdp->sd_unlinked_bitmap[x]);
kfree(sdp->sd_unlinked_bitmap);
}
}