This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / fs / gfs2 / lops.c
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
new file mode 100644 (file)
index 0000000..f82d84d
--- /dev/null
@@ -0,0 +1,825 @@
+/*
+ * 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 version 2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/lm_interface.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "glock.h"
+#include "log.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "recovery.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "util.h"
+
+static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
+{
+       struct gfs2_glock *gl;
+       struct gfs2_trans *tr = current->journal_info;
+
+       tr->tr_touched = 1;
+
+       gl = container_of(le, struct gfs2_glock, gl_le);
+       if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))
+               return;
+
+       gfs2_log_lock(sdp);
+       if (!list_empty(&le->le_list)){
+               gfs2_log_unlock(sdp);
+               return;
+       }
+       gfs2_glock_hold(gl);
+       set_bit(GLF_DIRTY, &gl->gl_flags);
+       sdp->sd_log_num_gl++;
+       list_add(&le->le_list, &sdp->sd_log_le_gl);
+       gfs2_log_unlock(sdp);
+}
+
+static void glock_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
+{
+       struct list_head *head = &sdp->sd_log_le_gl;
+       struct gfs2_glock *gl;
+
+       while (!list_empty(head)) {
+               gl = list_entry(head->next, struct gfs2_glock, gl_le.le_list);
+               list_del_init(&gl->gl_le.le_list);
+               sdp->sd_log_num_gl--;
+
+               gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl));
+               gfs2_glock_put(gl);
+       }
+       gfs2_assert_warn(sdp, !sdp->sd_log_num_gl);
+}
+
+static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
+{
+       struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
+       struct gfs2_trans *tr;
+
+       gfs2_log_lock(sdp);
+       if (!list_empty(&bd->bd_list_tr)) {
+               gfs2_log_unlock(sdp);
+               return;
+       }
+       tr = current->journal_info;
+       tr->tr_touched = 1;
+       tr->tr_num_buf++;
+       list_add(&bd->bd_list_tr, &tr->tr_list_buf);
+       gfs2_log_unlock(sdp);
+
+       if (!list_empty(&le->le_list))
+               return;
+
+       gfs2_trans_add_gl(bd->bd_gl);
+
+       gfs2_meta_check(sdp, bd->bd_bh);
+       gfs2_pin(sdp, bd->bd_bh);
+       gfs2_log_lock(sdp);
+       sdp->sd_log_num_buf++;
+       list_add(&le->le_list, &sdp->sd_log_le_buf);
+       gfs2_log_unlock(sdp);
+
+       tr->tr_num_buf_new++;
+}
+
+static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+       struct list_head *head = &tr->tr_list_buf;
+       struct gfs2_bufdata *bd;
+
+       gfs2_log_lock(sdp);
+       while (!list_empty(head)) {
+               bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
+               list_del_init(&bd->bd_list_tr);
+               tr->tr_num_buf--;
+       }
+       gfs2_log_unlock(sdp);
+       gfs2_assert_warn(sdp, !tr->tr_num_buf);
+}
+
+static void buf_lo_before_commit(struct gfs2_sbd *sdp)
+{
+       struct buffer_head *bh;
+       struct gfs2_log_descriptor *ld;
+       struct gfs2_bufdata *bd1 = NULL, *bd2;
+       unsigned int total = sdp->sd_log_num_buf;
+       unsigned int offset = sizeof(struct gfs2_log_descriptor);
+       unsigned int limit;
+       unsigned int num;
+       unsigned n;
+       __be64 *ptr;
+
+       offset += sizeof(__be64) - 1;
+       offset &= ~(sizeof(__be64) - 1);
+       limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
+       /* for 4k blocks, limit = 503 */
+
+       bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
+       while(total) {
+               num = total;
+               if (total > limit)
+                       num = limit;
+               bh = gfs2_log_get_buf(sdp);
+               sdp->sd_log_num_hdrs++;
+               ld = (struct gfs2_log_descriptor *)bh->b_data;
+               ptr = (__be64 *)(bh->b_data + offset);
+               ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
+               ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
+               ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
+               ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_METADATA);
+               ld->ld_length = cpu_to_be32(num + 1);
+               ld->ld_data1 = cpu_to_be32(num);
+               ld->ld_data2 = cpu_to_be32(0);
+               memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
+
+               n = 0;
+               list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf,
+                                            bd_le.le_list) {
+                       *ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
+                       if (++n >= num)
+                               break;
+               }
+
+               set_buffer_dirty(bh);
+               ll_rw_block(WRITE, 1, &bh);
+
+               n = 0;
+               list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
+                                            bd_le.le_list) {
+                       bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
+                       set_buffer_dirty(bh);
+                       ll_rw_block(WRITE, 1, &bh);
+                       if (++n >= num)
+                               break;
+               }
+
+               total -= num;
+       }
+}
+
+static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
+{
+       struct list_head *head = &sdp->sd_log_le_buf;
+       struct gfs2_bufdata *bd;
+
+       while (!list_empty(head)) {
+               bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
+               list_del_init(&bd->bd_le.le_list);
+               sdp->sd_log_num_buf--;
+
+               gfs2_unpin(sdp, bd->bd_bh, ai);
+       }
+       gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
+}
+
+static void buf_lo_before_scan(struct gfs2_jdesc *jd,
+                              struct gfs2_log_header_host *head, int pass)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+       if (pass != 0)
+               return;
+
+       sdp->sd_found_blocks = 0;
+       sdp->sd_replayed_blocks = 0;
+}
+
+static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
+                               struct gfs2_log_descriptor *ld, __be64 *ptr,
+                               int pass)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+       struct gfs2_glock *gl = ip->i_gl;
+       unsigned int blks = be32_to_cpu(ld->ld_data1);
+       struct buffer_head *bh_log, *bh_ip;
+       u64 blkno;
+       int error = 0;
+
+       if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
+               return 0;
+
+       gfs2_replay_incr_blk(sdp, &start);
+
+       for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
+               blkno = be64_to_cpu(*ptr++);
+
+               sdp->sd_found_blocks++;
+
+               if (gfs2_revoke_check(sdp, blkno, start))
+                       continue;
+
+               error = gfs2_replay_read_block(jd, start, &bh_log);
+               if (error)
+                       return error;
+
+               bh_ip = gfs2_meta_new(gl, blkno);
+               memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
+
+               if (gfs2_meta_check(sdp, bh_ip))
+                       error = -EIO;
+               else
+                       mark_buffer_dirty(bh_ip);
+
+               brelse(bh_log);
+               brelse(bh_ip);
+
+               if (error)
+                       break;
+
+               sdp->sd_replayed_blocks++;
+       }
+
+       return error;
+}
+
+static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+       if (error) {
+               gfs2_meta_sync(ip->i_gl);
+               return;
+       }
+       if (pass != 1)
+               return;
+
+       gfs2_meta_sync(ip->i_gl);
+
+       fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
+               jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
+}
+
+static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
+{
+       struct gfs2_trans *tr;
+
+       tr = current->journal_info;
+       tr->tr_touched = 1;
+       tr->tr_num_revoke++;
+
+       gfs2_log_lock(sdp);
+       sdp->sd_log_num_revoke++;
+       list_add(&le->le_list, &sdp->sd_log_le_revoke);
+       gfs2_log_unlock(sdp);
+}
+
+static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
+{
+       struct gfs2_log_descriptor *ld;
+       struct gfs2_meta_header *mh;
+       struct buffer_head *bh;
+       unsigned int offset;
+       struct list_head *head = &sdp->sd_log_le_revoke;
+       struct gfs2_revoke *rv;
+
+       if (!sdp->sd_log_num_revoke)
+               return;
+
+       bh = gfs2_log_get_buf(sdp);
+       ld = (struct gfs2_log_descriptor *)bh->b_data;
+       ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
+       ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
+       ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
+       ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_REVOKE);
+       ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke,
+                                                   sizeof(u64)));
+       ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
+       ld->ld_data2 = cpu_to_be32(0);
+       memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
+       offset = sizeof(struct gfs2_log_descriptor);
+
+       while (!list_empty(head)) {
+               rv = list_entry(head->next, struct gfs2_revoke, rv_le.le_list);
+               list_del_init(&rv->rv_le.le_list);
+               sdp->sd_log_num_revoke--;
+
+               if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
+                       set_buffer_dirty(bh);
+                       ll_rw_block(WRITE, 1, &bh);
+
+                       bh = gfs2_log_get_buf(sdp);
+                       mh = (struct gfs2_meta_header *)bh->b_data;
+                       mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
+                       mh->mh_type = cpu_to_be32(GFS2_METATYPE_LB);
+                       mh->mh_format = cpu_to_be32(GFS2_FORMAT_LB);
+                       offset = sizeof(struct gfs2_meta_header);
+               }
+
+               *(__be64 *)(bh->b_data + offset) = cpu_to_be64(rv->rv_blkno);
+               kfree(rv);
+
+               offset += sizeof(u64);
+       }
+       gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
+
+       set_buffer_dirty(bh);
+       ll_rw_block(WRITE, 1, &bh);
+}
+
+static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
+                                 struct gfs2_log_header_host *head, int pass)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+       if (pass != 0)
+               return;
+
+       sdp->sd_found_revokes = 0;
+       sdp->sd_replay_tail = head->lh_tail;
+}
+
+static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
+                                  struct gfs2_log_descriptor *ld, __be64 *ptr,
+                                  int pass)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+       unsigned int blks = be32_to_cpu(ld->ld_length);
+       unsigned int revokes = be32_to_cpu(ld->ld_data1);
+       struct buffer_head *bh;
+       unsigned int offset;
+       u64 blkno;
+       int first = 1;
+       int error;
+
+       if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
+               return 0;
+
+       offset = sizeof(struct gfs2_log_descriptor);
+
+       for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
+               error = gfs2_replay_read_block(jd, start, &bh);
+               if (error)
+                       return error;
+
+               if (!first)
+                       gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
+
+               while (offset + sizeof(u64) <= sdp->sd_sb.sb_bsize) {
+                       blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
+
+                       error = gfs2_revoke_add(sdp, blkno, start);
+                       if (error < 0)
+                               return error;
+                       else if (error)
+                               sdp->sd_found_revokes++;
+
+                       if (!--revokes)
+                               break;
+                       offset += sizeof(u64);
+               }
+
+               brelse(bh);
+               offset = sizeof(struct gfs2_meta_header);
+               first = 0;
+       }
+
+       return 0;
+}
+
+static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
+{
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+       if (error) {
+               gfs2_revoke_clean(sdp);
+               return;
+       }
+       if (pass != 1)
+               return;
+
+       fs_info(sdp, "jid=%u: Found %u revoke tags\n",
+               jd->jd_jid, sdp->sd_found_revokes);
+
+       gfs2_revoke_clean(sdp);
+}
+
+static void rg_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
+{
+       struct gfs2_rgrpd *rgd;
+       struct gfs2_trans *tr = current->journal_info;
+
+       tr->tr_touched = 1;
+
+       rgd = container_of(le, struct gfs2_rgrpd, rd_le);
+
+       gfs2_log_lock(sdp);
+       if (!list_empty(&le->le_list)){
+               gfs2_log_unlock(sdp);
+               return;
+       }
+       gfs2_rgrp_bh_hold(rgd);
+       sdp->sd_log_num_rg++;
+       list_add(&le->le_list, &sdp->sd_log_le_rg);
+       gfs2_log_unlock(sdp);
+}
+
+static void rg_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
+{
+       struct list_head *head = &sdp->sd_log_le_rg;
+       struct gfs2_rgrpd *rgd;
+
+       while (!list_empty(head)) {
+               rgd = list_entry(head->next, struct gfs2_rgrpd, rd_le.le_list);
+               list_del_init(&rgd->rd_le.le_list);
+               sdp->sd_log_num_rg--;
+
+               gfs2_rgrp_repolish_clones(rgd);
+               gfs2_rgrp_bh_put(rgd);
+       }
+       gfs2_assert_warn(sdp, !sdp->sd_log_num_rg);
+}
+
+/**
+ * databuf_lo_add - Add a databuf to the transaction.
+ *
+ * This is used in two distinct cases:
+ * i) In ordered write mode
+ *    We put the data buffer on a list so that we can ensure that its
+ *    synced to disk at the right time
+ * ii) In journaled data mode
+ *    We need to journal the data block in the same way as metadata in
+ *    the functions above. The difference is that here we have a tag
+ *    which is two __be64's being the block number (as per meta data)
+ *    and a flag which says whether the data block needs escaping or
+ *    not. This means we need a new log entry for each 251 or so data
+ *    blocks, which isn't an enormous overhead but twice as much as
+ *    for normal metadata blocks.
+ */
+static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
+{
+       struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
+       struct gfs2_trans *tr = current->journal_info;
+       struct address_space *mapping = bd->bd_bh->b_page->mapping;
+       struct gfs2_inode *ip = GFS2_I(mapping->host);
+
+       gfs2_log_lock(sdp);
+       tr->tr_touched = 1;
+       if (list_empty(&bd->bd_list_tr) &&
+           (ip->i_di.di_flags & GFS2_DIF_JDATA)) {
+               tr->tr_num_buf++;
+               list_add(&bd->bd_list_tr, &tr->tr_list_buf);
+               gfs2_log_unlock(sdp);
+               gfs2_pin(sdp, bd->bd_bh);
+               tr->tr_num_buf_new++;
+       } else {
+               gfs2_log_unlock(sdp);
+       }
+       gfs2_trans_add_gl(bd->bd_gl);
+       gfs2_log_lock(sdp);
+       if (list_empty(&le->le_list)) {
+               if (ip->i_di.di_flags & GFS2_DIF_JDATA)
+                       sdp->sd_log_num_jdata++;
+               sdp->sd_log_num_databuf++;
+               list_add(&le->le_list, &sdp->sd_log_le_databuf);
+       }
+       gfs2_log_unlock(sdp);
+}
+
+static int gfs2_check_magic(struct buffer_head *bh)
+{
+       struct page *page = bh->b_page;
+       void *kaddr;
+       __be32 *ptr;
+       int rv = 0;
+
+       kaddr = kmap_atomic(page, KM_USER0);
+       ptr = kaddr + bh_offset(bh);
+       if (*ptr == cpu_to_be32(GFS2_MAGIC))
+               rv = 1;
+       kunmap_atomic(kaddr, KM_USER0);
+
+       return rv;
+}
+
+/**
+ * databuf_lo_before_commit - Scan the data buffers, writing as we go
+ *
+ * Here we scan through the lists of buffers and make the assumption
+ * that any buffer thats been pinned is being journaled, and that
+ * any unpinned buffer is an ordered write data buffer and therefore
+ * will be written back rather than journaled.
+ */
+static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
+{
+       LIST_HEAD(started);
+       struct gfs2_bufdata *bd1 = NULL, *bd2, *bdt;
+       struct buffer_head *bh = NULL,*bh1 = NULL;
+       unsigned int offset = sizeof(struct gfs2_log_descriptor);
+       struct gfs2_log_descriptor *ld;
+       unsigned int limit;
+       unsigned int total_dbuf = sdp->sd_log_num_databuf;
+       unsigned int total_jdata = sdp->sd_log_num_jdata;
+       unsigned int num, n;
+       __be64 *ptr = NULL;
+
+       offset += 2*sizeof(__be64) - 1;
+       offset &= ~(2*sizeof(__be64) - 1);
+       limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
+
+       /*
+        * Start writing ordered buffers, write journaled buffers
+        * into the log along with a header
+        */
+       gfs2_log_lock(sdp);
+       bd2 = bd1 = list_prepare_entry(bd1, &sdp->sd_log_le_databuf,
+                                      bd_le.le_list);
+       while(total_dbuf) {
+               num = total_jdata;
+               if (num > limit)
+                       num = limit;
+               n = 0;
+               list_for_each_entry_safe_continue(bd1, bdt,
+                                                 &sdp->sd_log_le_databuf,
+                                                 bd_le.le_list) {
+                       /* store off the buffer head in a local ptr since
+                        * gfs2_bufdata might change when we drop the log lock
+                        */
+                       bh1 = bd1->bd_bh;
+
+                       /* An ordered write buffer */
+                       if (bh1 && !buffer_pinned(bh1)) {
+                               list_move(&bd1->bd_le.le_list, &started);
+                               if (bd1 == bd2) {
+                                       bd2 = NULL;
+                                       bd2 = list_prepare_entry(bd2,
+                                                       &sdp->sd_log_le_databuf,
+                                                       bd_le.le_list);
+                               }
+                               total_dbuf--;
+                               if (bh1) {
+                                       if (buffer_dirty(bh1)) {
+                                               get_bh(bh1);
+
+                                               gfs2_log_unlock(sdp);
+
+                                               ll_rw_block(SWRITE, 1, &bh1);
+                                               brelse(bh1);
+
+                                               gfs2_log_lock(sdp);
+                                       }
+                                       continue;
+                               }
+                               continue;
+                       } else if (bh1) { /* A journaled buffer */
+                               int magic;
+                               gfs2_log_unlock(sdp);
+                               if (!bh) {
+                                       bh = gfs2_log_get_buf(sdp);
+                                       sdp->sd_log_num_hdrs++;
+                                       ld = (struct gfs2_log_descriptor *)
+                                            bh->b_data;
+                                       ptr = (__be64 *)(bh->b_data + offset);
+                                       ld->ld_header.mh_magic =
+                                               cpu_to_be32(GFS2_MAGIC);
+                                       ld->ld_header.mh_type =
+                                               cpu_to_be32(GFS2_METATYPE_LD);
+                                       ld->ld_header.mh_format =
+                                               cpu_to_be32(GFS2_FORMAT_LD);
+                                       ld->ld_type =
+                                               cpu_to_be32(GFS2_LOG_DESC_JDATA);
+                                       ld->ld_length = cpu_to_be32(num + 1);
+                                       ld->ld_data1 = cpu_to_be32(num);
+                                       ld->ld_data2 = cpu_to_be32(0);
+                                       memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
+                               }
+                               magic = gfs2_check_magic(bh1);
+                               *ptr++ = cpu_to_be64(bh1->b_blocknr);
+                               *ptr++ = cpu_to_be64((__u64)magic);
+                               clear_buffer_escaped(bh1);
+                               if (unlikely(magic != 0))
+                                       set_buffer_escaped(bh1);
+                               gfs2_log_lock(sdp);
+                               if (n++ > num)
+                                       break;
+                       } else if (!bh1) {
+                               total_dbuf--;
+                               sdp->sd_log_num_databuf--;
+                               list_del_init(&bd1->bd_le.le_list);
+                               if (bd1 == bd2) {
+                                       bd2 = NULL;
+                                       bd2 = list_prepare_entry(bd2,
+                                               &sdp->sd_log_le_databuf,
+                                               bd_le.le_list);
+                                }
+                               kmem_cache_free(gfs2_bufdata_cachep, bd1);
+                       }
+               }
+               gfs2_log_unlock(sdp);
+               if (bh) {
+                       set_buffer_dirty(bh);
+                       ll_rw_block(WRITE, 1, &bh);
+                       bh = NULL;
+               }
+               n = 0;
+               gfs2_log_lock(sdp);
+               list_for_each_entry_continue(bd2, &sdp->sd_log_le_databuf,
+                                            bd_le.le_list) {
+                       if (!bd2->bd_bh)
+                               continue;
+                       /* copy buffer if it needs escaping */
+                       gfs2_log_unlock(sdp);
+                       if (unlikely(buffer_escaped(bd2->bd_bh))) {
+                               void *kaddr;
+                               struct page *page = bd2->bd_bh->b_page;
+                               bh = gfs2_log_get_buf(sdp);
+                               kaddr = kmap_atomic(page, KM_USER0);
+                               memcpy(bh->b_data,
+                                      kaddr + bh_offset(bd2->bd_bh),
+                                      sdp->sd_sb.sb_bsize);
+                               kunmap_atomic(kaddr, KM_USER0);
+                               *(__be32 *)bh->b_data = 0;
+                       } else {
+                               bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
+                       }
+                       set_buffer_dirty(bh);
+                       ll_rw_block(WRITE, 1, &bh);
+                       gfs2_log_lock(sdp);
+                       if (++n >= num)
+                               break;
+               }
+               bh = NULL;
+               total_dbuf -= num;
+               total_jdata -= num;
+       }
+       gfs2_log_unlock(sdp);
+
+       /* Wait on all ordered buffers */
+       while (!list_empty(&started)) {
+               gfs2_log_lock(sdp);
+               bd1 = list_entry(started.next, struct gfs2_bufdata,
+                                bd_le.le_list);
+               list_del_init(&bd1->bd_le.le_list);
+               sdp->sd_log_num_databuf--;
+               bh = bd1->bd_bh;
+               if (bh) {
+                       bh->b_private = NULL;
+                       get_bh(bh);
+                       gfs2_log_unlock(sdp);
+                       wait_on_buffer(bh);
+                       brelse(bh);
+               } else
+                       gfs2_log_unlock(sdp);
+
+               kmem_cache_free(gfs2_bufdata_cachep, bd1);
+       }
+
+       /* We've removed all the ordered write bufs here, so only jdata left */
+       gfs2_assert_warn(sdp, sdp->sd_log_num_databuf == sdp->sd_log_num_jdata);
+}
+
+static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
+                                   struct gfs2_log_descriptor *ld,
+                                   __be64 *ptr, int pass)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+       struct gfs2_glock *gl = ip->i_gl;
+       unsigned int blks = be32_to_cpu(ld->ld_data1);
+       struct buffer_head *bh_log, *bh_ip;
+       u64 blkno;
+       u64 esc;
+       int error = 0;
+
+       if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
+               return 0;
+
+       gfs2_replay_incr_blk(sdp, &start);
+       for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
+               blkno = be64_to_cpu(*ptr++);
+               esc = be64_to_cpu(*ptr++);
+
+               sdp->sd_found_blocks++;
+
+               if (gfs2_revoke_check(sdp, blkno, start))
+                       continue;
+
+               error = gfs2_replay_read_block(jd, start, &bh_log);
+               if (error)
+                       return error;
+
+               bh_ip = gfs2_meta_new(gl, blkno);
+               memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
+
+               /* Unescape */
+               if (esc) {
+                       __be32 *eptr = (__be32 *)bh_ip->b_data;
+                       *eptr = cpu_to_be32(GFS2_MAGIC);
+               }
+               mark_buffer_dirty(bh_ip);
+
+               brelse(bh_log);
+               brelse(bh_ip);
+               if (error)
+                       break;
+
+               sdp->sd_replayed_blocks++;
+       }
+
+       return error;
+}
+
+/* FIXME: sort out accounting for log blocks etc. */
+
+static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+       if (error) {
+               gfs2_meta_sync(ip->i_gl);
+               return;
+       }
+       if (pass != 1)
+               return;
+
+       /* data sync? */
+       gfs2_meta_sync(ip->i_gl);
+
+       fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
+               jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
+}
+
+static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
+{
+       struct list_head *head = &sdp->sd_log_le_databuf;
+       struct gfs2_bufdata *bd;
+
+       while (!list_empty(head)) {
+               bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
+               list_del_init(&bd->bd_le.le_list);
+               sdp->sd_log_num_databuf--;
+               sdp->sd_log_num_jdata--;
+               gfs2_unpin(sdp, bd->bd_bh, ai);
+       }
+       gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
+       gfs2_assert_warn(sdp, !sdp->sd_log_num_jdata);
+}
+
+
+const struct gfs2_log_operations gfs2_glock_lops = {
+       .lo_add = glock_lo_add,
+       .lo_after_commit = glock_lo_after_commit,
+       .lo_name = "glock",
+};
+
+const struct gfs2_log_operations gfs2_buf_lops = {
+       .lo_add = buf_lo_add,
+       .lo_incore_commit = buf_lo_incore_commit,
+       .lo_before_commit = buf_lo_before_commit,
+       .lo_after_commit = buf_lo_after_commit,
+       .lo_before_scan = buf_lo_before_scan,
+       .lo_scan_elements = buf_lo_scan_elements,
+       .lo_after_scan = buf_lo_after_scan,
+       .lo_name = "buf",
+};
+
+const struct gfs2_log_operations gfs2_revoke_lops = {
+       .lo_add = revoke_lo_add,
+       .lo_before_commit = revoke_lo_before_commit,
+       .lo_before_scan = revoke_lo_before_scan,
+       .lo_scan_elements = revoke_lo_scan_elements,
+       .lo_after_scan = revoke_lo_after_scan,
+       .lo_name = "revoke",
+};
+
+const struct gfs2_log_operations gfs2_rg_lops = {
+       .lo_add = rg_lo_add,
+       .lo_after_commit = rg_lo_after_commit,
+       .lo_name = "rg",
+};
+
+const struct gfs2_log_operations gfs2_databuf_lops = {
+       .lo_add = databuf_lo_add,
+       .lo_incore_commit = buf_lo_incore_commit,
+       .lo_before_commit = databuf_lo_before_commit,
+       .lo_after_commit = databuf_lo_after_commit,
+       .lo_scan_elements = databuf_lo_scan_elements,
+       .lo_after_scan = databuf_lo_after_scan,
+       .lo_name = "databuf",
+};
+
+const struct gfs2_log_operations *gfs2_log_ops[] = {
+       &gfs2_glock_lops,
+       &gfs2_buf_lops,
+       &gfs2_revoke_lops,
+       &gfs2_rg_lops,
+       &gfs2_databuf_lops,
+       NULL,
+};
+