glops.c

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/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2008 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/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/bio.h>
#include <linux/posix_acl.h>

#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "recovery.h"
#include "rgrp.h"
#include "util.h"
#include "trans.h"
#include "dir.h"

static void gfs2_ail_error(struct gfs2_glock *gl, const struct buffer_head *bh)
{
    fs_err(gl->gl_sbd, "AIL buffer %p: blocknr %llu state 0x%08lx mapping %p page state 0x%lx\n",
           bh, (unsigned long long)bh->b_blocknr, bh->b_state,
           bh->b_page->mapping, bh->b_page->flags);
    fs_err(gl->gl_sbd, "AIL glock %u:%llu mapping %p\n",
           gl->gl_name.ln_type, gl->gl_name.ln_number,
           gfs2_glock2aspace(gl));
    gfs2_lm_withdraw(gl->gl_sbd, "AIL error\n");
}

static void __gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
{
    struct gfs2_sbd *sdp = gl->gl_sbd;
    struct list_head *head = &gl->gl_ail_list;
    struct gfs2_bufdata *bd, *tmp;
    struct buffer_head *bh;
    const unsigned long b_state = (1UL << BH_Dirty)|(1UL << BH_Pinned)|(1UL << BH_Lock);
    sector_t blocknr;

    gfs2_log_lock(sdp);
    spin_lock(&sdp->sd_ail_lock);
    list_for_each_entry_safe(bd, tmp, head, bd_ail_gl_list) {
        bh = bd->bd_bh;
        if (bh->b_state & b_state) {
            if (fsync)
                continue;
            gfs2_ail_error(gl, bh);
        }
        blocknr = bh->b_blocknr;
        bh->b_private = NULL;
        gfs2_remove_from_ail(bd); /* drops ref on bh */

        bd->bd_bh = NULL;
        bd->bd_blkno = blocknr;

        gfs2_trans_add_revoke(sdp, bd);
    }
    BUG_ON(!fsync && atomic_read(&gl->gl_ail_count));
    spin_unlock(&sdp->sd_ail_lock);
    gfs2_log_unlock(sdp);
}


static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
{
    struct gfs2_sbd *sdp = gl->gl_sbd;
    struct gfs2_trans tr;

    memset(&tr, 0, sizeof(tr));
    tr.tr_revokes = atomic_read(&gl->gl_ail_count);

    if (!tr.tr_revokes)
        return;

    /* A shortened, inline version of gfs2_trans_begin() */
    tr.tr_reserved = 1 + gfs2_struct2blk(sdp, tr.tr_revokes, sizeof(u64));
    tr.tr_ip = (unsigned long)__builtin_return_address(0);
    sb_start_intwrite(sdp->sd_vfs);
    gfs2_log_reserve(sdp, tr.tr_reserved);
    BUG_ON(current->journal_info);
    current->journal_info = &tr;

    __gfs2_ail_flush(gl, 0);

    gfs2_trans_end(sdp);
    gfs2_log_flush(sdp, NULL);
}

void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
{
    struct gfs2_sbd *sdp = gl->gl_sbd;
    unsigned int revokes = atomic_read(&gl->gl_ail_count);
    int ret;

    if (!revokes)
        return;

    ret = gfs2_trans_begin(sdp, 0, revokes);
    if (ret)
        return;
    __gfs2_ail_flush(gl, fsync);
    gfs2_trans_end(sdp);
    gfs2_log_flush(sdp, NULL);
}

static void rgrp_go_sync(struct gfs2_glock *gl)
{
    struct address_space *metamapping = gfs2_glock2aspace(gl);
    struct gfs2_rgrpd *rgd;
    int error;

    if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags))
        return;
    BUG_ON(gl->gl_state != LM_ST_EXCLUSIVE);

    gfs2_log_flush(gl->gl_sbd, gl);
    filemap_fdatawrite(metamapping);
    error = filemap_fdatawait(metamapping);
        mapping_set_error(metamapping, error);
    gfs2_ail_empty_gl(gl);

    spin_lock(&gl->gl_spin);
    rgd = gl->gl_object;
    if (rgd)
        gfs2_free_clones(rgd);
    spin_unlock(&gl->gl_spin);
}

static void rgrp_go_inval(struct gfs2_glock *gl, int flags)
{
    struct address_space *mapping = gfs2_glock2aspace(gl);

    BUG_ON(!(flags & DIO_METADATA));
    gfs2_assert_withdraw(gl->gl_sbd, !atomic_read(&gl->gl_ail_count));
    truncate_inode_pages(mapping, 0);

    if (gl->gl_object) {
        struct gfs2_rgrpd *rgd = (struct gfs2_rgrpd *)gl->gl_object;
        rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
    }
}

static void inode_go_sync(struct gfs2_glock *gl)
{
    struct gfs2_inode *ip = gl->gl_object;
    struct address_space *metamapping = gfs2_glock2aspace(gl);
    int error;

    if (ip && !S_ISREG(ip->i_inode.i_mode))
        ip = NULL;
    if (ip && test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
        unmap_shared_mapping_range(ip->i_inode.i_mapping, 0, 0);
    if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags))
        return;

    BUG_ON(gl->gl_state != LM_ST_EXCLUSIVE);

    gfs2_log_flush(gl->gl_sbd, gl);
    filemap_fdatawrite(metamapping);
    if (ip) {
        struct address_space *mapping = ip->i_inode.i_mapping;
        filemap_fdatawrite(mapping);
        error = filemap_fdatawait(mapping);
        mapping_set_error(mapping, error);
    }
    error = filemap_fdatawait(metamapping);
    mapping_set_error(metamapping, error);
    gfs2_ail_empty_gl(gl);
    /*
     * Writeback of the data mapping may cause the dirty flag to be set
     * so we have to clear it again here.
     */
    smp_mb__before_clear_bit();
    clear_bit(GLF_DIRTY, &gl->gl_flags);
}

static void inode_go_inval(struct gfs2_glock *gl, int flags)
{
    struct gfs2_inode *ip = gl->gl_object;

    gfs2_assert_withdraw(gl->gl_sbd, !atomic_read(&gl->gl_ail_count));

    if (flags & DIO_METADATA) {
        struct address_space *mapping = gfs2_glock2aspace(gl);
        truncate_inode_pages(mapping, 0);
        if (ip) {
            set_bit(GIF_INVALID, &ip->i_flags);
            forget_all_cached_acls(&ip->i_inode);
            gfs2_dir_hash_inval(ip);
        }
    }

    if (ip == GFS2_I(gl->gl_sbd->sd_rindex)) {
        gfs2_log_flush(gl->gl_sbd, NULL);
        gl->gl_sbd->sd_rindex_uptodate = 0;
    }
    if (ip && S_ISREG(ip->i_inode.i_mode))
        truncate_inode_pages(ip->i_inode.i_mapping, 0);
}

static int inode_go_demote_ok(const struct gfs2_glock *gl)
{
    struct gfs2_sbd *sdp = gl->gl_sbd;
    struct gfs2_holder *gh;

    if (sdp->sd_jindex == gl->gl_object || sdp->sd_rindex == gl->gl_object)
        return 0;

    if (!list_empty(&gl->gl_holders)) {
        gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
        if (gh->gh_list.next != &gl->gl_holders)
            return 0;
    }

    return 1;
}

static void gfs2_set_nlink(struct inode *inode, u32 nlink)
{
    /*
     * We will need to review setting the nlink count here in the
     * light of the forthcoming ro bind mount work. This is a reminder
     * to do that.
     */
    if ((inode->i_nlink != nlink) && (inode->i_nlink != 0)) {
        if (nlink == 0)
            clear_nlink(inode);
        else
            set_nlink(inode, nlink);
    }
}

static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
{
    const struct gfs2_dinode *str = buf;
    struct timespec atime;
    u16 height, depth;

    if (unlikely(ip->i_no_addr != be64_to_cpu(str->di_num.no_addr)))
        goto corrupt;
    ip->i_no_formal_ino = be64_to_cpu(str->di_num.no_formal_ino);
    ip->i_inode.i_mode = be32_to_cpu(str->di_mode);
    ip->i_inode.i_rdev = 0;
    switch (ip->i_inode.i_mode & S_IFMT) {
    case S_IFBLK:
    case S_IFCHR:
        ip->i_inode.i_rdev = MKDEV(be32_to_cpu(str->di_major),
                       be32_to_cpu(str->di_minor));
        break;
    };

    ip->i_inode.i_uid = be32_to_cpu(str->di_uid);
    ip->i_inode.i_gid = be32_to_cpu(str->di_gid);
    gfs2_set_nlink(&ip->i_inode, be32_to_cpu(str->di_nlink));
    i_size_write(&ip->i_inode, be64_to_cpu(str->di_size));
    gfs2_set_inode_blocks(&ip->i_inode, be64_to_cpu(str->di_blocks));
    atime.tv_sec = be64_to_cpu(str->di_atime);
    atime.tv_nsec = be32_to_cpu(str->di_atime_nsec);
    if (timespec_compare(&ip->i_inode.i_atime, &atime) < 0)
        ip->i_inode.i_atime = atime;
    ip->i_inode.i_mtime.tv_sec = be64_to_cpu(str->di_mtime);
    ip->i_inode.i_mtime.tv_nsec = be32_to_cpu(str->di_mtime_nsec);
    ip->i_inode.i_ctime.tv_sec = be64_to_cpu(str->di_ctime);
    ip->i_inode.i_ctime.tv_nsec = be32_to_cpu(str->di_ctime_nsec);

    ip->i_goal = be64_to_cpu(str->di_goal_meta);
    ip->i_generation = be64_to_cpu(str->di_generation);

    ip->i_diskflags = be32_to_cpu(str->di_flags);
    ip->i_eattr = be64_to_cpu(str->di_eattr);
    /* i_diskflags and i_eattr must be set before gfs2_set_inode_flags() */
    gfs2_set_inode_flags(&ip->i_inode);
    height = be16_to_cpu(str->di_height);
    if (unlikely(height > GFS2_MAX_META_HEIGHT))
        goto corrupt;
    ip->i_height = (u8)height;

    depth = be16_to_cpu(str->di_depth);
    if (unlikely(depth > GFS2_DIR_MAX_DEPTH))
        goto corrupt;
    ip->i_depth = (u8)depth;
    ip->i_entries = be32_to_cpu(str->di_entries);

    if (S_ISREG(ip->i_inode.i_mode))
        gfs2_set_aops(&ip->i_inode);

    return 0;
corrupt:
    gfs2_consist_inode(ip);
    return -EIO;
}

int gfs2_inode_refresh(struct gfs2_inode *ip)
{
    struct buffer_head *dibh;
    int error;

    error = gfs2_meta_inode_buffer(ip, &dibh);
    if (error)
        return error;

    error = gfs2_dinode_in(ip, dibh->b_data);
    brelse(dibh);
    clear_bit(GIF_INVALID, &ip->i_flags);

    return error;
}

static int inode_go_lock(struct gfs2_holder *gh)
{
    struct gfs2_glock *gl = gh->gh_gl;
    struct gfs2_sbd *sdp = gl->gl_sbd;
    struct gfs2_inode *ip = gl->gl_object;
    int error = 0;

    if (!ip || (gh->gh_flags & GL_SKIP))
        return 0;

    if (test_bit(GIF_INVALID, &ip->i_flags)) {
        error = gfs2_inode_refresh(ip);
        if (error)
            return error;
    }

    if ((ip->i_diskflags & GFS2_DIF_TRUNC_IN_PROG) &&
        (gl->gl_state == LM_ST_EXCLUSIVE) &&
        (gh->gh_state == LM_ST_EXCLUSIVE)) {
        spin_lock(&sdp->sd_trunc_lock);
        if (list_empty(&ip->i_trunc_list))
            list_add(&sdp->sd_trunc_list, &ip->i_trunc_list);
        spin_unlock(&sdp->sd_trunc_lock);
        wake_up(&sdp->sd_quota_wait);
        return 1;
    }

    return error;
}

static int inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
{
    const struct gfs2_inode *ip = gl->gl_object;
    if (ip == NULL)
        return 0;
    gfs2_print_dbg(seq, " I: n:%llu/%llu t:%u f:0x%02lx d:0x%08x s:%llu\n",
          (unsigned long long)ip->i_no_formal_ino,
          (unsigned long long)ip->i_no_addr,
          IF2DT(ip->i_inode.i_mode), ip->i_flags,
          (unsigned int)ip->i_diskflags,
          (unsigned long long)i_size_read(&ip->i_inode));
    return 0;
}

static void trans_go_sync(struct gfs2_glock *gl)
{
    struct gfs2_sbd *sdp = gl->gl_sbd;

    if (gl->gl_state != LM_ST_UNLOCKED &&
        test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
        gfs2_meta_syncfs(sdp);
        gfs2_log_shutdown(sdp);
    }
}

static int trans_go_xmote_bh(struct gfs2_glock *gl, struct gfs2_holder *gh)
{
    struct gfs2_sbd *sdp = gl->gl_sbd;
    struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
    struct gfs2_glock *j_gl = ip->i_gl;
    struct gfs2_log_header_host head;
    int error;

    if (test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
        j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);

        error = gfs2_find_jhead(sdp->sd_jdesc, &head);
        if (error)
            gfs2_consist(sdp);
        if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
            gfs2_consist(sdp);

        /*  Initialize some head of the log stuff  */
        if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
            sdp->sd_log_sequence = head.lh_sequence + 1;
            gfs2_log_pointers_init(sdp, head.lh_blkno);
        }
    }
    return 0;
}

static int trans_go_demote_ok(const struct gfs2_glock *gl)
{
    return 0;
}

static void iopen_go_callback(struct gfs2_glock *gl)
{
    struct gfs2_inode *ip = (struct gfs2_inode *)gl->gl_object;
    struct gfs2_sbd *sdp = gl->gl_sbd;

    if (sdp->sd_vfs->s_flags & MS_RDONLY)
        return;

    if (gl->gl_demote_state == LM_ST_UNLOCKED &&
        gl->gl_state == LM_ST_SHARED && ip) {
        gfs2_glock_hold(gl);
        if (queue_work(gfs2_delete_workqueue, &gl->gl_delete) == 0)
            gfs2_glock_put_nolock(gl);
    }
}

const struct gfs2_glock_operations gfs2_meta_glops = {
    .go_type = LM_TYPE_META,
};

const struct gfs2_glock_operations gfs2_inode_glops = {
    .go_xmote_th = inode_go_sync,
    .go_inval = inode_go_inval,
    .go_demote_ok = inode_go_demote_ok,
    .go_lock = inode_go_lock,
    .go_dump = inode_go_dump,
    .go_type = LM_TYPE_INODE,
    .go_flags = GLOF_ASPACE,
};

const struct gfs2_glock_operations gfs2_rgrp_glops = {
    .go_xmote_th = rgrp_go_sync,
    .go_inval = rgrp_go_inval,
    .go_lock = gfs2_rgrp_go_lock,
    .go_unlock = gfs2_rgrp_go_unlock,
    .go_dump = gfs2_rgrp_dump,
    .go_type = LM_TYPE_RGRP,
    .go_flags = GLOF_ASPACE,
};

const struct gfs2_glock_operations gfs2_trans_glops = {
    .go_xmote_th = trans_go_sync,
    .go_xmote_bh = trans_go_xmote_bh,
    .go_demote_ok = trans_go_demote_ok,
    .go_type = LM_TYPE_NONDISK,
};

const struct gfs2_glock_operations gfs2_iopen_glops = {
    .go_type = LM_TYPE_IOPEN,
    .go_callback = iopen_go_callback,
};

const struct gfs2_glock_operations gfs2_flock_glops = {
    .go_type = LM_TYPE_FLOCK,
};

const struct gfs2_glock_operations gfs2_nondisk_glops = {
    .go_type = LM_TYPE_NONDISK,
};

const struct gfs2_glock_operations gfs2_quota_glops = {
    .go_type = LM_TYPE_QUOTA,
};

const struct gfs2_glock_operations gfs2_journal_glops = {
    .go_type = LM_TYPE_JOURNAL,
};

const struct gfs2_glock_operations *gfs2_glops_list[] = {
    [LM_TYPE_META] = &gfs2_meta_glops,
    [LM_TYPE_INODE] = &gfs2_inode_glops,
    [LM_TYPE_RGRP] = &gfs2_rgrp_glops,
    [LM_TYPE_IOPEN] = &gfs2_iopen_glops,
    [LM_TYPE_FLOCK] = &gfs2_flock_glops,
    [LM_TYPE_NONDISK] = &gfs2_nondisk_glops,
    [LM_TYPE_QUOTA] = &gfs2_quota_glops,
    [LM_TYPE_JOURNAL] = &gfs2_journal_glops,
};