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linux/fs/gfs2/super.c
Steven Whitehouse f45b7ddd2b [GFS2] Use a bio to read the superblock 
This means that we don't need to create a special inode just to contain
a struct address_space in order to read a single disk block. Instead
we read the disk block directly. Its slightly faster, and uses slightly
less memory, but the real reason for doing this is that it removes a
special case from the glock code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-27 13:53:53 -04:00

978 lines
22 KiB
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/*
* 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 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/crc32.h>
#include <linux/gfs2_ondisk.h>
#include <linux/bio.h>
#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "dir.h"
#include "format.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "quota.h"
#include "recovery.h"
#include "rgrp.h"
#include "super.h"
#include "trans.h"
#include "util.h"
/**
* gfs2_tune_init - Fill a gfs2_tune structure with default values
* @gt: tune
*
*/
void gfs2_tune_init(struct gfs2_tune *gt)
{
spin_lock_init(&gt->gt_spin);
gt->gt_ilimit = 100;
gt->gt_ilimit_tries = 3;
gt->gt_ilimit_min = 1;
gt->gt_demote_secs = 300;
gt->gt_incore_log_blocks = 1024;
gt->gt_log_flush_secs = 60;
gt->gt_jindex_refresh_secs = 60;
gt->gt_scand_secs = 15;
gt->gt_recoverd_secs = 60;
gt->gt_logd_secs = 1;
gt->gt_quotad_secs = 5;
gt->gt_quota_simul_sync = 64;
gt->gt_quota_warn_period = 10;
gt->gt_quota_scale_num = 1;
gt->gt_quota_scale_den = 1;
gt->gt_quota_cache_secs = 300;
gt->gt_quota_quantum = 60;
gt->gt_atime_quantum = 3600;
gt->gt_new_files_jdata = 0;
gt->gt_new_files_directio = 0;
gt->gt_max_atomic_write = 4 << 20;
gt->gt_max_readahead = 1 << 18;
gt->gt_lockdump_size = 131072;
gt->gt_stall_secs = 600;
gt->gt_complain_secs = 10;
gt->gt_reclaim_limit = 5000;
gt->gt_entries_per_readdir = 32;
gt->gt_prefetch_secs = 10;
gt->gt_greedy_default = HZ / 10;
gt->gt_greedy_quantum = HZ / 40;
gt->gt_greedy_max = HZ / 4;
gt->gt_statfs_quantum = 30;
gt->gt_statfs_slow = 0;
}
/**
* gfs2_check_sb - Check superblock
* @sdp: the filesystem
* @sb: The superblock
* @silent: Don't print a message if the check fails
*
* Checks the version code of the FS is one that we understand how to
* read and that the sizes of the various on-disk structures have not
* changed.
*/
int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb *sb, int silent)
{
unsigned int x;
if (sb->sb_header.mh_magic != GFS2_MAGIC ||
sb->sb_header.mh_type != GFS2_METATYPE_SB) {
if (!silent)
printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
return -EINVAL;
}
/* If format numbers match exactly, we're done. */
if (sb->sb_fs_format == GFS2_FORMAT_FS &&
sb->sb_multihost_format == GFS2_FORMAT_MULTI)
return 0;
if (sb->sb_fs_format != GFS2_FORMAT_FS) {
for (x = 0; gfs2_old_fs_formats[x]; x++)
if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
break;
if (!gfs2_old_fs_formats[x]) {
printk(KERN_WARNING
"GFS2: code version (%u, %u) is incompatible "
"with ondisk format (%u, %u)\n",
GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
sb->sb_fs_format, sb->sb_multihost_format);
printk(KERN_WARNING
"GFS2: I don't know how to upgrade this FS\n");
return -EINVAL;
}
}
if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
for (x = 0; gfs2_old_multihost_formats[x]; x++)
if (gfs2_old_multihost_formats[x] ==
sb->sb_multihost_format)
break;
if (!gfs2_old_multihost_formats[x]) {
printk(KERN_WARNING
"GFS2: code version (%u, %u) is incompatible "
"with ondisk format (%u, %u)\n",
GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
sb->sb_fs_format, sb->sb_multihost_format);
printk(KERN_WARNING
"GFS2: I don't know how to upgrade this FS\n");
return -EINVAL;
}
}
if (!sdp->sd_args.ar_upgrade) {
printk(KERN_WARNING
"GFS2: code version (%u, %u) is incompatible "
"with ondisk format (%u, %u)\n",
GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
sb->sb_fs_format, sb->sb_multihost_format);
printk(KERN_INFO
"GFS2: Use the \"upgrade\" mount option to upgrade "
"the FS\n");
printk(KERN_INFO "GFS2: See the manual for more details\n");
return -EINVAL;
}
return 0;
}
static int end_bio_io_page(struct bio *bio, unsigned int bytes_done, int error)
{
struct page *page = bio->bi_private;
if (bio->bi_size)
return 1;
if (!error)
SetPageUptodate(page);
unlock_page(page);
return 0;
}
static struct page *gfs2_read_super(struct super_block *sb, sector_t sector)
{
struct page *page;
struct bio *bio;
page = alloc_page(GFP_KERNEL);
if (unlikely(!page))
return NULL;
ClearPageUptodate(page);
ClearPageDirty(page);
lock_page(page);
bio = bio_alloc(GFP_KERNEL, 1);
if (unlikely(!bio)) {
__free_page(page);
return NULL;
}
bio->bi_sector = sector;
bio->bi_bdev = sb->s_bdev;
bio_add_page(bio, page, PAGE_SIZE, 0);
bio->bi_end_io = end_bio_io_page;
bio->bi_private = page;
submit_bio(READ | BIO_RW_SYNC, bio);
wait_on_page_locked(page);
bio_put(bio);
if (!PageUptodate(page)) {
__free_page(page);
return NULL;
}
return page;
}
/**
* gfs2_read_sb - Read super block
* @sdp: The GFS2 superblock
* @gl: the glock for the superblock (assumed to be held)
* @silent: Don't print message if mount fails
*
*/
int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
{
uint32_t hash_blocks, ind_blocks, leaf_blocks;
uint32_t tmp_blocks;
unsigned int x;
int error;
struct page *page;
char *sb;
page = gfs2_read_super(sdp->sd_vfs, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
if (!page) {
if (!silent)
fs_err(sdp, "can't read superblock\n");
return -EIO;
}
sb = kmap(page);
gfs2_sb_in(&sdp->sd_sb, sb);
kunmap(page);
__free_page(page);
error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
if (error)
return error;
sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
GFS2_BASIC_BLOCK_SHIFT;
sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
sizeof(struct gfs2_dinode)) / sizeof(uint64_t);
sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
sizeof(struct gfs2_meta_header)) / sizeof(uint64_t);
sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t);
sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
sizeof(struct gfs2_meta_header)) /
sizeof(struct gfs2_quota_change);
/* Compute maximum reservation required to add a entry to a directory */
hash_blocks = DIV_ROUND_UP(sizeof(uint64_t) * (1 << GFS2_DIR_MAX_DEPTH),
sdp->sd_jbsize);
ind_blocks = 0;
for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
ind_blocks += tmp_blocks;
}
leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
sizeof(struct gfs2_dinode);
sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
for (x = 2;; x++) {
uint64_t space, d;
uint32_t m;
space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
d = space;
m = do_div(d, sdp->sd_inptrs);
if (d != sdp->sd_heightsize[x - 1] || m)
break;
sdp->sd_heightsize[x] = space;
}
sdp->sd_max_height = x;
gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
sizeof(struct gfs2_dinode);
sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
for (x = 2;; x++) {
uint64_t space, d;
uint32_t m;
space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
d = space;
m = do_div(d, sdp->sd_inptrs);
if (d != sdp->sd_jheightsize[x - 1] || m)
break;
sdp->sd_jheightsize[x] = space;
}
sdp->sd_max_jheight = x;
gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
return 0;
}
/**
* gfs2_jindex_hold - Grab a lock on the jindex
* @sdp: The GFS2 superblock
* @ji_gh: the holder for the jindex glock
*
* This is very similar to the gfs2_rindex_hold() function, except that
* in general we hold the jindex lock for longer periods of time and
* we grab it far less frequently (in general) then the rgrp lock.
*
* Returns: errno
*/
int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
{
struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
struct qstr name;
char buf[20];
struct gfs2_jdesc *jd;
int error;
name.name = buf;
mutex_lock(&sdp->sd_jindex_mutex);
for (;;) {
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED,
GL_LOCAL_EXCL, ji_gh);
if (error)
break;
name.len = sprintf(buf, "journal%u", sdp->sd_journals);
name.hash = gfs2_disk_hash(name.name, name.len);
error = gfs2_dir_search(sdp->sd_jindex, &name, NULL, NULL);
if (error == -ENOENT) {
error = 0;
break;
}
gfs2_glock_dq_uninit(ji_gh);
if (error)
break;
error = -ENOMEM;
jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
if (!jd)
break;
jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
if (!jd->jd_inode)
error = -ENOENT;
else
error = PTR_ERR(jd->jd_inode);
kfree(jd);
break;
}
spin_lock(&sdp->sd_jindex_spin);
jd->jd_jid = sdp->sd_journals++;
list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
spin_unlock(&sdp->sd_jindex_spin);
}
mutex_unlock(&sdp->sd_jindex_mutex);
return error;
}
/**
* gfs2_jindex_free - Clear all the journal index information
* @sdp: The GFS2 superblock
*
*/
void gfs2_jindex_free(struct gfs2_sbd *sdp)
{
struct list_head list;
struct gfs2_jdesc *jd;
spin_lock(&sdp->sd_jindex_spin);
list_add(&list, &sdp->sd_jindex_list);
list_del_init(&sdp->sd_jindex_list);
sdp->sd_journals = 0;
spin_unlock(&sdp->sd_jindex_spin);
while (!list_empty(&list)) {
jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
list_del(&jd->jd_list);
iput(jd->jd_inode);
kfree(jd);
}
}
static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
{
struct gfs2_jdesc *jd;
int found = 0;
list_for_each_entry(jd, head, jd_list) {
if (jd->jd_jid == jid) {
found = 1;
break;
}
}
if (!found)
jd = NULL;
return jd;
}
struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
{
struct gfs2_jdesc *jd;
spin_lock(&sdp->sd_jindex_spin);
jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
spin_unlock(&sdp->sd_jindex_spin);
return jd;
}
void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
{
struct gfs2_jdesc *jd;
spin_lock(&sdp->sd_jindex_spin);
jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
if (jd)
jd->jd_dirty = 1;
spin_unlock(&sdp->sd_jindex_spin);
}
struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
{
struct gfs2_jdesc *jd;
int found = 0;
spin_lock(&sdp->sd_jindex_spin);
list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
if (jd->jd_dirty) {
jd->jd_dirty = 0;
found = 1;
break;
}
}
spin_unlock(&sdp->sd_jindex_spin);
if (!found)
jd = NULL;
return jd;
}
int gfs2_jdesc_check(struct gfs2_jdesc *jd)
{
struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
int ar;
int error;
if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
(ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
gfs2_consist_inode(ip);
return -EIO;
}
jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
if (!error && ar) {
gfs2_consist_inode(ip);
error = -EIO;
}
return error;
}
/**
* gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
* @sdp: the filesystem
*
* Returns: errno
*/
int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
{
struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
struct gfs2_glock *j_gl = ip->i_gl;
struct gfs2_holder t_gh;
struct gfs2_log_header head;
int error;
error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
GL_LOCAL_EXCL, &t_gh);
if (error)
return error;
gfs2_meta_cache_flush(ip);
j_gl->gl_ops->go_inval(j_gl, DIO_METADATA | DIO_DATA);
error = gfs2_find_jhead(sdp->sd_jdesc, &head);
if (error)
goto fail;
if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
gfs2_consist(sdp);
error = -EIO;
goto fail;
}
/* Initialize some head of the log stuff */
sdp->sd_log_sequence = head.lh_sequence + 1;
gfs2_log_pointers_init(sdp, head.lh_blkno);
error = gfs2_quota_init(sdp);
if (error)
goto fail_unlinked;
set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
gfs2_glock_dq_uninit(&t_gh);
return 0;
fail_unlinked:
fail:
t_gh.gh_flags |= GL_NOCACHE;
gfs2_glock_dq_uninit(&t_gh);
return error;
}
/**
* gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
* @sdp: the filesystem
*
* Returns: errno
*/
int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
{
struct gfs2_holder t_gh;
int error;
gfs2_quota_sync(sdp);
gfs2_statfs_sync(sdp);
error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
GL_LOCAL_EXCL | GL_NOCACHE,
&t_gh);
if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
return error;
gfs2_meta_syncfs(sdp);
gfs2_log_shutdown(sdp);
clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
if (t_gh.gh_gl)
gfs2_glock_dq_uninit(&t_gh);
gfs2_quota_cleanup(sdp);
return error;
}
int gfs2_statfs_init(struct gfs2_sbd *sdp)
{
struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
struct buffer_head *m_bh, *l_bh;
struct gfs2_holder gh;
int error;
error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
&gh);
if (error)
return error;
error = gfs2_meta_inode_buffer(m_ip, &m_bh);
if (error)
goto out;
if (sdp->sd_args.ar_spectator) {
spin_lock(&sdp->sd_statfs_spin);
gfs2_statfs_change_in(m_sc, m_bh->b_data +
sizeof(struct gfs2_dinode));
spin_unlock(&sdp->sd_statfs_spin);
} else {
error = gfs2_meta_inode_buffer(l_ip, &l_bh);
if (error)
goto out_m_bh;
spin_lock(&sdp->sd_statfs_spin);
gfs2_statfs_change_in(m_sc, m_bh->b_data +
sizeof(struct gfs2_dinode));
gfs2_statfs_change_in(l_sc, l_bh->b_data +
sizeof(struct gfs2_dinode));
spin_unlock(&sdp->sd_statfs_spin);
brelse(l_bh);
}
out_m_bh:
brelse(m_bh);
out:
gfs2_glock_dq_uninit(&gh);
return 0;
}
void gfs2_statfs_change(struct gfs2_sbd *sdp, int64_t total, int64_t free,
int64_t dinodes)
{
struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
struct buffer_head *l_bh;
int error;
error = gfs2_meta_inode_buffer(l_ip, &l_bh);
if (error)
return;
mutex_lock(&sdp->sd_statfs_mutex);
gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
mutex_unlock(&sdp->sd_statfs_mutex);
spin_lock(&sdp->sd_statfs_spin);
l_sc->sc_total += total;
l_sc->sc_free += free;
l_sc->sc_dinodes += dinodes;
gfs2_statfs_change_out(l_sc, l_bh->b_data +
sizeof(struct gfs2_dinode));
spin_unlock(&sdp->sd_statfs_spin);
brelse(l_bh);
}
int gfs2_statfs_sync(struct gfs2_sbd *sdp)
{
struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
struct gfs2_holder gh;
struct buffer_head *m_bh, *l_bh;
int error;
error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
&gh);
if (error)
return error;
error = gfs2_meta_inode_buffer(m_ip, &m_bh);
if (error)
goto out;
spin_lock(&sdp->sd_statfs_spin);
gfs2_statfs_change_in(m_sc, m_bh->b_data +
sizeof(struct gfs2_dinode));
if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
spin_unlock(&sdp->sd_statfs_spin);
goto out_bh;
}
spin_unlock(&sdp->sd_statfs_spin);
error = gfs2_meta_inode_buffer(l_ip, &l_bh);
if (error)
goto out_bh;
error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
if (error)
goto out_bh2;
mutex_lock(&sdp->sd_statfs_mutex);
gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
mutex_unlock(&sdp->sd_statfs_mutex);
spin_lock(&sdp->sd_statfs_spin);
m_sc->sc_total += l_sc->sc_total;
m_sc->sc_free += l_sc->sc_free;
m_sc->sc_dinodes += l_sc->sc_dinodes;
memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
memset(l_bh->b_data + sizeof(struct gfs2_dinode),
0, sizeof(struct gfs2_statfs_change));
spin_unlock(&sdp->sd_statfs_spin);
gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
gfs2_trans_end(sdp);
out_bh2:
brelse(l_bh);
out_bh:
brelse(m_bh);
out:
gfs2_glock_dq_uninit(&gh);
return error;
}
/**
* gfs2_statfs_i - Do a statfs
* @sdp: the filesystem
* @sg: the sg structure
*
* Returns: errno
*/
int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
{
struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
spin_lock(&sdp->sd_statfs_spin);
*sc = *m_sc;
sc->sc_total += l_sc->sc_total;
sc->sc_free += l_sc->sc_free;
sc->sc_dinodes += l_sc->sc_dinodes;
spin_unlock(&sdp->sd_statfs_spin);
if (sc->sc_free < 0)
sc->sc_free = 0;
if (sc->sc_free > sc->sc_total)
sc->sc_free = sc->sc_total;
if (sc->sc_dinodes < 0)
sc->sc_dinodes = 0;
return 0;
}
/**
* statfs_fill - fill in the sg for a given RG
* @rgd: the RG
* @sc: the sc structure
*
* Returns: 0 on success, -ESTALE if the LVB is invalid
*/
static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
struct gfs2_statfs_change *sc)
{
gfs2_rgrp_verify(rgd);
sc->sc_total += rgd->rd_ri.ri_data;
sc->sc_free += rgd->rd_rg.rg_free;
sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
return 0;
}
/**
* gfs2_statfs_slow - Stat a filesystem using asynchronous locking
* @sdp: the filesystem
* @sc: the sc info that will be returned
*
* Any error (other than a signal) will cause this routine to fall back
* to the synchronous version.
*
* FIXME: This really shouldn't busy wait like this.
*
* Returns: errno
*/
int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
{
struct gfs2_holder ri_gh;
struct gfs2_rgrpd *rgd_next;
struct gfs2_holder *gha, *gh;
unsigned int slots = 64;
unsigned int x;
int done;
int error = 0, err;
memset(sc, 0, sizeof(struct gfs2_statfs_change));
gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
if (!gha)
return -ENOMEM;
error = gfs2_rindex_hold(sdp, &ri_gh);
if (error)
goto out;
rgd_next = gfs2_rgrpd_get_first(sdp);
for (;;) {
done = 1;
for (x = 0; x < slots; x++) {
gh = gha + x;
if (gh->gh_gl && gfs2_glock_poll(gh)) {
err = gfs2_glock_wait(gh);
if (err) {
gfs2_holder_uninit(gh);
error = err;
} else {
if (!error)
error = statfs_slow_fill(
gh->gh_gl->gl_object, sc);
gfs2_glock_dq_uninit(gh);
}
}
if (gh->gh_gl)
done = 0;
else if (rgd_next && !error) {
error = gfs2_glock_nq_init(rgd_next->rd_gl,
LM_ST_SHARED,
GL_ASYNC,
gh);
rgd_next = gfs2_rgrpd_get_next(rgd_next);
done = 0;
}
if (signal_pending(current))
error = -ERESTARTSYS;
}
if (done)
break;
yield();
}
gfs2_glock_dq_uninit(&ri_gh);
out:
kfree(gha);
return error;
}
struct lfcc {
struct list_head list;
struct gfs2_holder gh;
};
/**
* gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
* journals are clean
* @sdp: the file system
* @state: the state to put the transaction lock into
* @t_gh: the hold on the transaction lock
*
* Returns: errno
*/
static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
struct gfs2_holder *t_gh)
{
struct gfs2_inode *ip;
struct gfs2_holder ji_gh;
struct gfs2_jdesc *jd;
struct lfcc *lfcc;
LIST_HEAD(list);
struct gfs2_log_header lh;
int error;
error = gfs2_jindex_hold(sdp, &ji_gh);
if (error)
return error;
list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
if (!lfcc) {
error = -ENOMEM;
goto out;
}
ip = GFS2_I(jd->jd_inode);
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
if (error) {
kfree(lfcc);
goto out;
}
list_add(&lfcc->list, &list);
}
error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
LM_FLAG_PRIORITY | GL_NOCACHE,
t_gh);
list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
error = gfs2_jdesc_check(jd);
if (error)
break;
error = gfs2_find_jhead(jd, &lh);
if (error)
break;
if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
error = -EBUSY;
break;
}
}
if (error)
gfs2_glock_dq_uninit(t_gh);
out:
while (!list_empty(&list)) {
lfcc = list_entry(list.next, struct lfcc, list);
list_del(&lfcc->list);
gfs2_glock_dq_uninit(&lfcc->gh);
kfree(lfcc);
}
gfs2_glock_dq_uninit(&ji_gh);
return error;
}
/**
* gfs2_freeze_fs - freezes the file system
* @sdp: the file system
*
* This function flushes data and meta data for all machines by
* aquiring the transaction log exclusively. All journals are
* ensured to be in a clean state as well.
*
* Returns: errno
*/
int gfs2_freeze_fs(struct gfs2_sbd *sdp)
{
int error = 0;
mutex_lock(&sdp->sd_freeze_lock);
if (!sdp->sd_freeze_count++) {
error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
if (error)
sdp->sd_freeze_count--;
}
mutex_unlock(&sdp->sd_freeze_lock);
return error;
}
/**
* gfs2_unfreeze_fs - unfreezes the file system
* @sdp: the file system
*
* This function allows the file system to proceed by unlocking
* the exclusively held transaction lock. Other GFS2 nodes are
* now free to acquire the lock shared and go on with their lives.
*
*/
void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
{
mutex_lock(&sdp->sd_freeze_lock);
if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
mutex_unlock(&sdp->sd_freeze_lock);
}
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