fs/gfs2/trans.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/kallsyms.h>
  16 #include <linux/gfs2_ondisk.h>
  17
  18 #include "gfs2.h"
  19 #include "incore.h"
  20 #include "glock.h"
  21 #include "log.h"
  22 #include "lops.h"
  23 #include "meta_io.h"
  24 #include "trans.h"
  25 #include "util.h"
  26 #include "trace_gfs2.h"
  27
  28 int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
  29                      unsigned int revokes)
  30 {
  31         struct gfs2_trans *tr;
  32         int error;
  33
  34         BUG_ON(current->journal_info);
  35         BUG_ON(blocks == 0 && revokes == 0);
  36
  37         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
  38                 return -EROFS;
  39
  40         tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);
  41         if (!tr)
  42                 return -ENOMEM;
  43
  44         tr->tr_ip = (unsigned long)__builtin_return_address(0);
  45         tr->tr_blocks = blocks;
  46         tr->tr_revokes = revokes;
  47         tr->tr_reserved = 1;
  48         if (blocks)
  49                 tr->tr_reserved += 6 + blocks;
  50         if (revokes)
  51                 tr->tr_reserved += gfs2_struct2blk(sdp, revokes,
  52                                                    sizeof(u64));
  53         gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &tr->tr_t_gh);
  54
  55         error = gfs2_glock_nq(&tr->tr_t_gh);
  56         if (error)
  57                 goto fail_holder_uninit;
  58
  59         error = gfs2_log_reserve(sdp, tr->tr_reserved);
  60         if (error)
  61                 goto fail_gunlock;
  62
  63         current->journal_info = tr;
  64
  65         return 0;
  66
  67 fail_gunlock:
  68         gfs2_glock_dq(&tr->tr_t_gh);
  69
  70 fail_holder_uninit:
  71         gfs2_holder_uninit(&tr->tr_t_gh);
  72         kfree(tr);
  73
  74         return error;
  75 }
  76
  77 /**
  78  * gfs2_log_release - Release a given number of log blocks
  79  * @sdp: The GFS2 superblock
  80  * @blks: The number of blocks
  81  *
  82  */
  83
  84 static void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
  85 {
  86
  87         atomic_add(blks, &sdp->sd_log_blks_free);
  88         trace_gfs2_log_blocks(sdp, blks);
  89         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
  90                                   sdp->sd_jdesc->jd_blocks);
  91         up_read(&sdp->sd_log_flush_lock);
  92 }
  93
  94 static void gfs2_print_trans(const struct gfs2_trans *tr)
  95 {
  96         print_symbol(KERN_WARNING "GFS2: Transaction created at: %s\n", tr->tr_ip);
  97         printk(KERN_WARNING "GFS2: blocks=%u revokes=%u reserved=%u touched=%d\n",
  98                tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
  99         printk(KERN_WARNING "GFS2: Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
 100                tr->tr_num_buf_new, tr->tr_num_buf_rm,
 101                tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
 102                tr->tr_num_revoke, tr->tr_num_revoke_rm);
 103 }
 104
 105 void gfs2_trans_end(struct gfs2_sbd *sdp)
 106 {
 107         struct gfs2_trans *tr = current->journal_info;
 108         s64 nbuf;
 109         BUG_ON(!tr);
 110         current->journal_info = NULL;
 111
 112         if (!tr->tr_touched) {
 113                 gfs2_log_release(sdp, tr->tr_reserved);
 114                 if (tr->tr_t_gh.gh_gl) {
 115                         gfs2_glock_dq(&tr->tr_t_gh);
 116                         gfs2_holder_uninit(&tr->tr_t_gh);
 117                         kfree(tr);
 118                 }
 119                 return;
 120         }
 121
 122         nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
 123         nbuf -= tr->tr_num_buf_rm;
 124         nbuf -= tr->tr_num_databuf_rm;
 125
 126         if (gfs2_assert_withdraw(sdp, (nbuf <= tr->tr_blocks) &&
 127                                        (tr->tr_num_revoke <= tr->tr_revokes)))
 128                 gfs2_print_trans(tr);
 129
 130         gfs2_log_commit(sdp, tr);
 131         if (tr->tr_t_gh.gh_gl) {
 132                 gfs2_glock_dq(&tr->tr_t_gh);
 133                 gfs2_holder_uninit(&tr->tr_t_gh);
 134                 kfree(tr);
 135         }
 136
 137         if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
 138                 gfs2_log_flush(sdp, NULL);
 139 }
 140
 141 /**
 142  * gfs2_trans_add_bh - Add a to-be-modified buffer to the current transaction
 143  * @gl: the glock the buffer belongs to
 144  * @bh: The buffer to add
 145  * @meta: True in the case of adding metadata
 146  *
 147  */
 148
 149 void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
 150 {
 151         struct gfs2_sbd *sdp = gl->gl_sbd;
 152         struct gfs2_bufdata *bd;
 153
 154         bd = bh->b_private;
 155         if (bd)
 156                 gfs2_assert(sdp, bd->bd_gl == gl);
 157         else {
 158                 gfs2_attach_bufdata(gl, bh, meta);
 159                 bd = bh->b_private;
 160         }
 161         lops_add(sdp, &bd->bd_le);
 162 }
 163
 164 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 165 {
 166         BUG_ON(!list_empty(&bd->bd_le.le_list));
 167         BUG_ON(!list_empty(&bd->bd_ail_st_list));
 168         BUG_ON(!list_empty(&bd->bd_ail_gl_list));
 169         lops_init_le(&bd->bd_le, &gfs2_revoke_lops);
 170         lops_add(sdp, &bd->bd_le);
 171 }
 172
 173 void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
 174 {
 175         struct gfs2_bufdata *bd, *tmp;
 176         struct gfs2_trans *tr = current->journal_info;
 177         unsigned int n = len;
 178
 179         gfs2_log_lock(sdp);
 180         list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_le.le_list) {
 181                 if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
 182                         list_del_init(&bd->bd_le.le_list);
 183                         gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
 184                         sdp->sd_log_num_revoke--;
 185                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 186                         tr->tr_num_revoke_rm++;
 187                         if (--n == 0)
 188                                 break;
 189                 }
 190         }
 191         gfs2_log_unlock(sdp);
 192 }
 193