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 "inode.h"
  22 #include "log.h"
  23 #include "lops.h"
  24 #include "meta_io.h"
  25 #include "trans.h"
  26 #include "util.h"
  27 #include "trace_gfs2.h"
  28
  29 int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
  30                      unsigned int revokes)
  31 {
  32         struct gfs2_trans *tr;
  33         int error;
  34
  35         BUG_ON(current->journal_info);
  36         BUG_ON(blocks == 0 && revokes == 0);
  37
  38         if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
  39                 return -EROFS;
  40
  41         tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);
  42         if (!tr)
  43                 return -ENOMEM;
  44
  45         tr->tr_ip = (unsigned long)__builtin_return_address(0);
  46         tr->tr_blocks = blocks;
  47         tr->tr_revokes = revokes;
  48         tr->tr_reserved = 1;
  49         if (blocks)
  50                 tr->tr_reserved += 6 + blocks;
  51         if (revokes)
  52                 tr->tr_reserved += gfs2_struct2blk(sdp, revokes,
  53                                                    sizeof(u64));
  54         sb_start_intwrite(sdp->sd_vfs);
  55         gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &tr->tr_t_gh);
  56
  57         error = gfs2_glock_nq(&tr->tr_t_gh);
  58         if (error)
  59                 goto fail_holder_uninit;
  60
  61         error = gfs2_log_reserve(sdp, tr->tr_reserved);
  62         if (error)
  63                 goto fail_gunlock;
  64
  65         current->journal_info = tr;
  66
  67         return 0;
  68
  69 fail_gunlock:
  70         gfs2_glock_dq(&tr->tr_t_gh);
  71
  72 fail_holder_uninit:
  73         sb_end_intwrite(sdp->sd_vfs);
  74         gfs2_holder_uninit(&tr->tr_t_gh);
  75         kfree(tr);
  76
  77         return error;
  78 }
  79
  80 /**
  81  * gfs2_log_release - Release a given number of log blocks
  82  * @sdp: The GFS2 superblock
  83  * @blks: The number of blocks
  84  *
  85  */
  86
  87 static void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
  88 {
  89
  90         atomic_add(blks, &sdp->sd_log_blks_free);
  91         trace_gfs2_log_blocks(sdp, blks);
  92         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
  93                                   sdp->sd_jdesc->jd_blocks);
  94         up_read(&sdp->sd_log_flush_lock);
  95 }
  96
  97 static void gfs2_print_trans(const struct gfs2_trans *tr)
  98 {
  99         print_symbol(KERN_WARNING "GFS2: Transaction created at: %s\n", tr->tr_ip);
 100         printk(KERN_WARNING "GFS2: blocks=%u revokes=%u reserved=%u touched=%d\n",
 101                tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
 102         printk(KERN_WARNING "GFS2: Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
 103                tr->tr_num_buf_new, tr->tr_num_buf_rm,
 104                tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
 105                tr->tr_num_revoke, tr->tr_num_revoke_rm);
 106 }
 107
 108 void gfs2_trans_end(struct gfs2_sbd *sdp)
 109 {
 110         struct gfs2_trans *tr = current->journal_info;
 111         s64 nbuf;
 112         BUG_ON(!tr);
 113         current->journal_info = NULL;
 114
 115         if (!tr->tr_touched) {
 116                 gfs2_log_release(sdp, tr->tr_reserved);
 117                 if (tr->tr_t_gh.gh_gl) {
 118                         gfs2_glock_dq(&tr->tr_t_gh);
 119                         gfs2_holder_uninit(&tr->tr_t_gh);
 120                         kfree(tr);
 121                 }
 122                 sb_end_intwrite(sdp->sd_vfs);
 123                 return;
 124         }
 125
 126         nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
 127         nbuf -= tr->tr_num_buf_rm;
 128         nbuf -= tr->tr_num_databuf_rm;
 129
 130         if (gfs2_assert_withdraw(sdp, (nbuf <= tr->tr_blocks) &&
 131                                        (tr->tr_num_revoke <= tr->tr_revokes)))
 132                 gfs2_print_trans(tr);
 133
 134         gfs2_log_commit(sdp, tr);
 135         if (tr->tr_t_gh.gh_gl) {
 136                 gfs2_glock_dq(&tr->tr_t_gh);
 137                 gfs2_holder_uninit(&tr->tr_t_gh);
 138                 kfree(tr);
 139         }
 140
 141         if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
 142                 gfs2_log_flush(sdp, NULL);
 143         sb_end_intwrite(sdp->sd_vfs);
 144 }
 145
 146 static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl,
 147                                                struct buffer_head *bh,
 148                                                const struct gfs2_log_operations *lops)
 149 {
 150         struct gfs2_bufdata *bd;
 151
 152         bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
 153         bd->bd_bh = bh;
 154         bd->bd_gl = gl;
 155         bd->bd_ops = lops;
 156         INIT_LIST_HEAD(&bd->bd_list);
 157         bh->b_private = bd;
 158         return bd;
 159 }
 160
 161 /**
 162  * gfs2_trans_add_data - Add a databuf to the transaction.
 163  * @gl: The inode glock associated with the buffer
 164  * @bh: The buffer to add
 165  *
 166  * This is used in two distinct cases:
 167  * i) In ordered write mode
 168  *    We put the data buffer on a list so that we can ensure that its
 169  *    synced to disk at the right time
 170  * ii) In journaled data mode
 171  *    We need to journal the data block in the same way as metadata in
 172  *    the functions above. The difference is that here we have a tag
 173  *    which is two __be64's being the block number (as per meta data)
 174  *    and a flag which says whether the data block needs escaping or
 175  *    not. This means we need a new log entry for each 251 or so data
 176  *    blocks, which isn't an enormous overhead but twice as much as
 177  *    for normal metadata blocks.
 178  */
 179 void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
 180 {
 181         struct gfs2_trans *tr = current->journal_info;
 182         struct gfs2_sbd *sdp = gl->gl_sbd;
 183         struct address_space *mapping = bh->b_page->mapping;
 184         struct gfs2_inode *ip = GFS2_I(mapping->host);
 185         struct gfs2_bufdata *bd;
 186
 187         if (!gfs2_is_jdata(ip)) {
 188                 gfs2_ordered_add_inode(ip);
 189                 return;
 190         }
 191
 192         lock_buffer(bh);
 193         gfs2_log_lock(sdp);
 194         bd = bh->b_private;
 195         if (bd == NULL) {
 196                 gfs2_log_unlock(sdp);
 197                 unlock_buffer(bh);
 198                 if (bh->b_private == NULL)
 199                         bd = gfs2_alloc_bufdata(gl, bh, &gfs2_databuf_lops);
 200                 lock_buffer(bh);
 201                 gfs2_log_lock(sdp);
 202         }
 203         gfs2_assert(sdp, bd->bd_gl == gl);
 204         tr->tr_touched = 1;
 205         if (list_empty(&bd->bd_list)) {
 206                 set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 207                 set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
 208                 gfs2_pin(sdp, bd->bd_bh);
 209                 tr->tr_num_databuf_new++;
 210                 sdp->sd_log_num_databuf++;
 211                 list_add_tail(&bd->bd_list, &sdp->sd_log_le_databuf);
 212         }
 213         gfs2_log_unlock(sdp);
 214         unlock_buffer(bh);
 215 }
 216
 217 static void meta_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 218 {
 219         struct gfs2_meta_header *mh;
 220         struct gfs2_trans *tr;
 221
 222         tr = current->journal_info;
 223         tr->tr_touched = 1;
 224         if (!list_empty(&bd->bd_list))
 225                 return;
 226         set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 227         set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
 228         mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
 229         if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) {
 230                 printk(KERN_ERR
 231                        "Attempting to add uninitialised block to journal (inplace block=%lld)\n",
 232                        (unsigned long long)bd->bd_bh->b_blocknr);
 233                 BUG();
 234         }
 235         gfs2_pin(sdp, bd->bd_bh);
 236         mh->__pad0 = cpu_to_be64(0);
 237         mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
 238         sdp->sd_log_num_buf++;
 239         list_add(&bd->bd_list, &sdp->sd_log_le_buf);
 240         tr->tr_num_buf_new++;
 241 }
 242
 243 void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
 244 {
 245
 246         struct gfs2_sbd *sdp = gl->gl_sbd;
 247         struct gfs2_bufdata *bd;
 248
 249         lock_buffer(bh);
 250         gfs2_log_lock(sdp);
 251         bd = bh->b_private;
 252         if (bd == NULL) {
 253                 gfs2_log_unlock(sdp);
 254                 unlock_buffer(bh);
 255                 lock_page(bh->b_page);
 256                 if (bh->b_private == NULL)
 257                         bd = gfs2_alloc_bufdata(gl, bh, &gfs2_buf_lops);
 258                 unlock_page(bh->b_page);
 259                 lock_buffer(bh);
 260                 gfs2_log_lock(sdp);
 261         }
 262         gfs2_assert(sdp, bd->bd_gl == gl);
 263         meta_lo_add(sdp, bd);
 264         gfs2_log_unlock(sdp);
 265         unlock_buffer(bh);
 266 }
 267
 268 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 269 {
 270         struct gfs2_glock *gl = bd->bd_gl;
 271         struct gfs2_trans *tr = current->journal_info;
 272
 273         BUG_ON(!list_empty(&bd->bd_list));
 274         BUG_ON(!list_empty(&bd->bd_ail_st_list));
 275         BUG_ON(!list_empty(&bd->bd_ail_gl_list));
 276         bd->bd_ops = &gfs2_revoke_lops;
 277         tr->tr_touched = 1;
 278         tr->tr_num_revoke++;
 279         sdp->sd_log_num_revoke++;
 280         atomic_inc(&gl->gl_revokes);
 281         set_bit(GLF_LFLUSH, &gl->gl_flags);
 282         list_add(&bd->bd_list, &sdp->sd_log_le_revoke);
 283 }
 284
 285 void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
 286 {
 287         struct gfs2_bufdata *bd, *tmp;
 288         struct gfs2_trans *tr = current->journal_info;
 289         unsigned int n = len;
 290
 291         gfs2_log_lock(sdp);
 292         list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_list) {
 293                 if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
 294                         list_del_init(&bd->bd_list);
 295                         gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
 296                         sdp->sd_log_num_revoke--;
 297                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 298                         tr->tr_num_revoke_rm++;
 299                         if (--n == 0)
 300                                 break;
 301                 }
 302         }
 303         gfs2_log_unlock(sdp);
 304 }
 305