[GFS2] The core of GFS2

This patch contains all the core files for GFS2.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 944 insertions, 0 deletions

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
new file mode 100644
index 000000000000..d37f203e133b
--- /dev/null
+++ b/fs/gfs2/super.c
@@ -0,0 +1,944 @@
+/*
+ * 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 "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 "unlinked.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_inoded_secs = 15;
+        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("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("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("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("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("GFS2: I don't know how to upgrade this FS\n");
+                        return -EINVAL;
+                }
+        }
+
+        if (!sdp->sd_args.ar_upgrade) {
+                printk("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("GFS2: Use the \"upgrade\" mount option to upgrade "
+                       "the FS\n");
+                printk("GFS2: See the manual for more details\n");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+/**
+ * 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)
+{
+        struct buffer_head *bh;
+        uint32_t hash_blocks, ind_blocks, leaf_blocks;
+        uint32_t tmp_blocks;
+        unsigned int x;
+        int error;
+
+        error = gfs2_meta_read(gl, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift,
+                               DIO_FORCE | DIO_START | DIO_WAIT, &bh);
+        if (error) {
+                if (!silent)
+                        fs_err(sdp, "can't read superblock\n");
+                return error;
+        }
+
+        gfs2_assert(sdp, sizeof(struct gfs2_sb) <= bh->b_size);
+        gfs2_sb_in(&sdp->sd_sb, bh->b_data);
+        brelse(bh);
+
+        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_ut_per_block = (sdp->sd_sb.sb_bsize -
+                                sizeof(struct gfs2_meta_header)) /
+                               sizeof(struct gfs2_unlinked_tag);
+        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_RU(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_RU(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;
+}
+
+int gfs2_do_upgrade(struct gfs2_sbd *sdp, struct gfs2_glock *sb_gl)
+{
+        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 = sdp->sd_jindex;
+        struct qstr name;
+        char buf[20];
+        struct gfs2_jdesc *jd;
+        int error;
+
+        name.name = buf;
+
+        down(&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);
+
+                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;
+
+                error = gfs2_lookupi(dip, &name, 1, &jd->jd_inode);
+                if (error) {
+                        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);
+        }
+
+        up(&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);
+                gfs2_inode_put(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 = jd->jd_inode;
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        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;
+}
+
+int gfs2_lookup_master_dir(struct gfs2_sbd *sdp)
+{
+        struct gfs2_glock *gl;
+        int error;
+
+        error = gfs2_glock_get(sdp,
+                               sdp->sd_sb.sb_master_dir.no_addr,
+                               &gfs2_inode_glops, CREATE, &gl);
+        if (!error) {
+                error = gfs2_inode_get(gl, &sdp->sd_sb.sb_master_dir, CREATE,
+                                       &sdp->sd_master_dir);
+                gfs2_glock_put(gl);
+        }
+
+        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_glock *j_gl = sdp->sd_jdesc->jd_inode->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 | GL_NEVER_RECURSE, &t_gh);
+        if (error)
+                return error;
+
+        gfs2_meta_cache_flush(sdp->sd_jdesc->jd_inode);
+        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_unlinked_init(sdp);
+        if (error)
+                goto fail;
+        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:
+        gfs2_unlinked_cleanup(sdp);
+
+ 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_unlinked_dealloc(sdp);
+        gfs2_quota_sync(sdp);
+        gfs2_statfs_sync(sdp);
+
+        error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
+                                GL_LOCAL_EXCL | GL_NEVER_RECURSE | 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_unlinked_cleanup(sdp);
+        gfs2_quota_cleanup(sdp);
+
+        return error;
+}
+
+int gfs2_statfs_init(struct gfs2_sbd *sdp)
+{
+        struct gfs2_inode *m_ip = sdp->sd_statfs_inode;
+        struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
+        struct gfs2_inode *l_ip = 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 = 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;
+
+        down(&sdp->sd_statfs_mutex);
+        gfs2_trans_add_bh(l_ip->i_gl, l_bh);
+        up(&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 = sdp->sd_statfs_inode;
+        struct gfs2_inode *l_ip = 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;
+
+        down(&sdp->sd_statfs_mutex);
+        gfs2_trans_add_bh(l_ip->i_gl, l_bh);
+        up(&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);
+        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(get_gl2rgd(gh->gh_gl), 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
+ */
+
+int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp, struct gfs2_holder *t_gh)
+{
+        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;
+                }
+                error = gfs2_glock_nq_init(jd->jd_inode->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_NEVER_RECURSE | 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;
+
+        down(&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--;
+        }
+
+        up(&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)
+{
+        down(&sdp->sd_freeze_lock);
+
+        if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
+                gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
+
+        up(&sdp->sd_freeze_lock);
+}
+