text: /*
   * 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/bio.h>
  #include <linux/fs.h>
  
  #include "gfs2.h"
  #include "incore.h"
  #include "inode.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"
  #include "trace_gfs2.h"
  
  /**
   * gfs2_pin - Pin a buffer in memory
   * @sdp: The superblock
   * @bh: The buffer to be pinned
   *
   * The log lock must be held when calling this function
   */
  void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
  {
  	struct gfs2_bufdata *bd;
  
  	BUG_ON(!current->journal_info);
  
  	clear_buffer_dirty(bh);
  	if (test_set_buffer_pinned(bh))
  		gfs2_assert_withdraw(sdp, 0);
  	if (!buffer_uptodate(bh))
  		gfs2_io_error_bh(sdp, bh);
  	bd = bh->b_private;
  	/* If this buffer is in the AIL and it has already been written
  	 * to in-place disk block, remove it from the AIL.
  	 */
  	spin_lock(&sdp->sd_ail_lock);
  	if (bd->bd_ail)
  		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
  	spin_unlock(&sdp->sd_ail_lock);
  	get_bh(bh);
  	trace_gfs2_pin(bd, 1);
  }
  
  static bool buffer_is_rgrp(const struct gfs2_bufdata *bd)
  {
  	return bd->bd_gl->gl_name.ln_type == LM_TYPE_RGRP;
  }
  
  static void maybe_release_space(struct gfs2_bufdata *bd)
  {
  	struct gfs2_glock *gl = bd->bd_gl;
  	struct gfs2_sbd *sdp = gl->gl_sbd;
  	struct gfs2_rgrpd *rgd = gl->gl_object;
  	unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
  	struct gfs2_bitmap *bi = rgd->rd_bits + index;
  
  	if (bi->bi_clone == 0)
  		return;
  	if (sdp->sd_args.ar_discard)
  		gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bd->bd_bh, bi, 1, NULL);
  	memcpy(bi->bi_clone + bi->bi_offset,
  	       bd->bd_bh->b_data + bi->bi_offset, bi->bi_len);
  	clear_bit(GBF_FULL, &bi->bi_flags);
  	rgd->rd_free_clone = rgd->rd_free;
  	rgd->rd_extfail_pt = rgd->rd_free;
  }
  
  /**
   * gfs2_unpin - Unpin a buffer
   * @sdp: the filesystem the buffer belongs to
   * @bh: The buffer to unpin
   * @ai:
   * @flags: The inode dirty flags
   *
   */
  
  static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
  		       struct gfs2_ail *ai)
  {
  	struct gfs2_bufdata *bd = bh->b_private;
  
  	BUG_ON(!buffer_uptodate(bh));
  	BUG_ON(!buffer_pinned(bh));
  
  	lock_buffer(bh);
  	mark_buffer_dirty(bh);
  	clear_buffer_pinned(bh);
  
  	if (buffer_is_rgrp(bd))
  		maybe_release_space(bd);
  
  	spin_lock(&sdp->sd_ail_lock);
  	if (bd->bd_ail) {
  		list_del(&bd->bd_ail_st_list);
  		brelse(bh);
  	} else {
  		struct gfs2_glock *gl = bd->bd_gl;
  		list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
  		atomic_inc(&gl->gl_ail_count);
  	}
  	bd->bd_ail = ai;
  	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
  	spin_unlock(&sdp->sd_ail_lock);
  
  	clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
  	trace_gfs2_pin(bd, 0);
  	unlock_buffer(bh);
  }
  
  
  static inline struct gfs2_log_descriptor *bh_log_desc(struct buffer_head *bh)
  {
  	return (struct gfs2_log_descriptor *)bh->b_data;
  }
  
  static inline __be64 *bh_log_ptr(struct buffer_head *bh)
  {
  	struct gfs2_log_descriptor *ld = bh_log_desc(bh);
  	return (__force __be64 *)(ld + 1);
  }
  
  static inline __be64 *bh_ptr_end(struct buffer_head *bh)
  {
  	return (__force __be64 *)(bh->b_data + bh->b_size);
  }
  
  
  /**
   * gfs2_log_write_endio - End of I/O for a log buffer
   * @bh: The buffer head
   * @uptodate: I/O Status
   *
   */
  
  static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
  {
  	struct gfs2_sbd *sdp = bh->b_private;
  	bh->b_private = NULL;
  
  	end_buffer_write_sync(bh, uptodate);
  	if (atomic_dec_and_test(&sdp->sd_log_in_flight))
  		wake_up(&sdp->sd_log_flush_wait);
  }
  
  /**
   * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
   * @sdp: The GFS2 superblock
   *
   * Returns: the buffer_head
   */
  
  static struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
  {
  	u64 blkno = gfs2_log_bmap(sdp, sdp->sd_log_flush_head);
  	struct buffer_head *bh;
  
  	bh = sb_getblk(sdp->sd_vfs, blkno);
  	lock_buffer(bh);
  	memset(bh->b_data, 0, bh->b_size);
  	set_buffer_uptodate(bh);
  	clear_buffer_dirty(bh);
  	gfs2_log_incr_head(sdp);
  	atomic_inc(&sdp->sd_log_in_flight);
  	bh->b_private = sdp;
  	bh->b_end_io = gfs2_log_write_endio;
  
  	return bh;
  }
  
  /**
   * gfs2_fake_write_endio - 
   * @bh: The buffer head
   * @uptodate: The I/O Status
   *
   */
  
  static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
  {
  	struct buffer_head *real_bh = bh->b_private;
  	struct gfs2_bufdata *bd = real_bh->b_private;
  	struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
  
  	end_buffer_write_sync(bh, uptodate);
  	mempool_free(bh, gfs2_bh_pool);
  	unlock_buffer(real_bh);
  	brelse(real_bh);
  	if (atomic_dec_and_test(&sdp->sd_log_in_flight))
  		wake_up(&sdp->sd_log_flush_wait);
  }
  
  /**
   * gfs2_log_write_buf - write metadata buffer to log
   * @sdp: the filesystem
   * @real: the in-place buffer head
   *
   * Returns: the log buffer descriptor
   */
  
  static void gfs2_log_write_buf(struct gfs2_sbd *sdp, struct buffer_head *real)
  {
  	u64 blkno = gfs2_log_bmap(sdp, sdp->sd_log_flush_head);
  	struct buffer_head *bh;
  
  	bh = mempool_alloc(gfs2_bh_pool, GFP_NOFS);
  	atomic_set(&bh->b_count, 1);
  	bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
  	set_bh_page(bh, real->b_page, bh_offset(real));
  	bh->b_blocknr = blkno;
  	bh->b_size = sdp->sd_sb.sb_bsize;
  	bh->b_bdev = sdp->sd_vfs->s_bdev;
  	bh->b_private = real;
  	bh->b_end_io = gfs2_fake_write_endio;
  
  	gfs2_log_incr_head(sdp);
  	atomic_inc(&sdp->sd_log_in_flight);
  
  	submit_bh(WRITE, bh);
  }
  
  static struct buffer_head *gfs2_get_log_desc(struct gfs2_sbd *sdp, u32 ld_type)
  {
  	struct buffer_head *bh = gfs2_log_get_buf(sdp);
  	struct gfs2_log_descriptor *ld = bh_log_desc(bh);
  	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(ld_type);
  	ld->ld_length = 0;
  	ld->ld_data1 = 0;
  	ld->ld_data2 = 0;
  	memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
  	return bh;
  }
  
  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;
  	unsigned int limit;
  	unsigned int num;
  	unsigned n;
  	__be64 *ptr;
  
  	limit = buf_limit(sdp);
  	/* for 4k blocks, limit = 503 */
  
  	gfs2_log_lock(sdp);
  	total = sdp->sd_log_num_buf;
  	bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_list);
  	while(total) {
  		num = total;
  		if (total > limit)
  			num = limit;
  		gfs2_log_unlock(sdp);
  		bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_METADATA);
  		gfs2_log_lock(sdp);
  		ld = bh_log_desc(bh);
  		ptr = bh_log_ptr(bh);
  		ld->ld_length = cpu_to_be32(num + 1);
  		ld->ld_data1 = cpu_to_be32(num);
  
  		n = 0;
  		list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf, bd_list) {
  			*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
  			if (++n >= num)
  				break;
  		}
  
  		gfs2_log_unlock(sdp);
  		submit_bh(WRITE, bh);
  		gfs2_log_lock(sdp);
  
  		n = 0;
  		list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf, bd_list) {
  			get_bh(bd2->bd_bh);
  			gfs2_log_unlock(sdp);
  			lock_buffer(bd2->bd_bh);
  			gfs2_log_write_buf(sdp, bd2->bd_bh);
  			gfs2_log_lock(sdp);
  			if (++n >= num)
  				break;
  		}
  
  		BUG_ON(total < num);
  		total -= num;
  	}
  	gfs2_log_unlock(sdp);
  }
  
  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_list);
  		list_del_init(&bd->bd_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_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_bufdata *bd;
  
  	if (!sdp->sd_log_num_revoke)
  		return;
  
  	bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE);
  	ld = bh_log_desc(bh);
  	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);
  	offset = sizeof(struct gfs2_log_descriptor);
  
  	list_for_each_entry(bd, head, bd_list) {
  		sdp->sd_log_num_revoke--;
  
  		if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
  			submit_bh(WRITE, 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(bd->bd_blkno);
  		offset += sizeof(u64);
  	}
  	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
  
  	submit_bh(WRITE, bh);
  }
  
  static void revoke_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
  {
  	struct list_head *head = &sdp->sd_log_le_revoke;
  	struct gfs2_bufdata *bd;
  	struct gfs2_glock *gl;
  
  	while (!list_empty(head)) {
  		bd = list_entry(head->next, struct gfs2_bufdata, bd_list);
  		list_del_init(&bd->bd_list);
  		gl = bd->bd_gl;
  		atomic_dec(&gl->gl_revokes);
  		clear_bit(GLF_LFLUSH, &gl->gl_flags);
  		kmem_cache_free(gfs2_bufdata_cachep, bd);
  	}
  }
  
  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) {
  				brelse(bh);
  				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 gfs2_check_magic(struct buffer_head *bh)
  {
  	void *kaddr;
  	__be32 *ptr;
  
  	clear_buffer_escaped(bh);
  	kaddr = kmap_atomic(bh->b_page, KM_USER0);
  	ptr = kaddr + bh_offset(bh);
  	if (*ptr == cpu_to_be32(GFS2_MAGIC))
  		set_buffer_escaped(bh);
  	kunmap_atomic(kaddr, KM_USER0);
  }
  
  static void gfs2_write_blocks(struct gfs2_sbd *sdp, struct buffer_head *bh,
  			      struct list_head *list, struct list_head *done,
  			      unsigned int n)
  {
  	struct buffer_head *bh1;
  	struct gfs2_log_descriptor *ld;
  	struct gfs2_bufdata *bd;
  	__be64 *ptr;
  
  	if (!bh)
  		return;
  
  	ld = bh_log_desc(bh);
  	ld->ld_length = cpu_to_be32(n + 1);
  	ld->ld_data1 = cpu_to_be32(n);
  
  	ptr = bh_log_ptr(bh);
  	
  	get_bh(bh);
  	submit_bh(WRITE, bh);
  	gfs2_log_lock(sdp);
  	while(!list_empty(list)) {
  		bd = list_entry(list->next, struct gfs2_bufdata, bd_list);
  		list_move_tail(&bd->bd_list, done);
  		get_bh(bd->bd_bh);
  		while (be64_to_cpu(*ptr) != bd->bd_bh->b_blocknr) {
  			gfs2_log_incr_head(sdp);
  			ptr += 2;
  		}
  		gfs2_log_unlock(sdp);
  		lock_buffer(bd->bd_bh);
  		if (buffer_escaped(bd->bd_bh)) {
  			void *kaddr;
  			bh1 = gfs2_log_get_buf(sdp);
  			kaddr = kmap_atomic(bd->bd_bh->b_page, KM_USER0);
  			memcpy(bh1->b_data, kaddr + bh_offset(bd->bd_bh),
  			       bh1->b_size);
  			kunmap_atomic(kaddr, KM_USER0);
  			*(__be32 *)bh1->b_data = 0;
  			clear_buffer_escaped(bd->bd_bh);
  			unlock_buffer(bd->bd_bh);
  			brelse(bd->bd_bh);
  			submit_bh(WRITE, bh1);
  		} else {
  			gfs2_log_write_buf(sdp, bd->bd_bh);
  		}
  		gfs2_log_lock(sdp);
  		ptr += 2;
  	}
  	gfs2_log_unlock(sdp);
  	brelse(bh);
  }
  
  /**
   * databuf_lo_before_commit - Scan the data buffers, writing as we go
   *
   */
  
  static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
  {
  	struct gfs2_bufdata *bd = NULL;
  	struct buffer_head *bh = NULL;
  	unsigned int n = 0;
  	__be64 *ptr = NULL, *end = NULL;
  	LIST_HEAD(processed);
  	LIST_HEAD(in_progress);
  
  	gfs2_log_lock(sdp);
  	while (!list_empty(&sdp->sd_log_le_databuf)) {
  		if (ptr == end) {
  			gfs2_log_unlock(sdp);
  			gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
  			n = 0;
  			bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_JDATA);
  			ptr = bh_log_ptr(bh);
  			end = bh_ptr_end(bh) - 1;
  			gfs2_log_lock(sdp);
  			continue;
  		}
  		bd = list_entry(sdp->sd_log_le_databuf.next, struct gfs2_bufdata, bd_list);
  		list_move_tail(&bd->bd_list, &in_progress);
  		gfs2_check_magic(bd->bd_bh);
  		*ptr++ = cpu_to_be64(bd->bd_bh->b_blocknr);
  		*ptr++ = cpu_to_be64(buffer_escaped(bh) ? 1 : 0);
  		n++;
  	}
  	gfs2_log_unlock(sdp);
  	gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
  	gfs2_log_lock(sdp);
  	list_splice(&processed, &sdp->sd_log_le_databuf);
  	gfs2_log_unlock(sdp);
  }
  
  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);
  
  		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_list);
  		list_del_init(&bd->bd_list);
  		sdp->sd_log_num_databuf--;
  		gfs2_unpin(sdp, bd->bd_bh, ai);
  	}
  	gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
  }
  
  
  const struct gfs2_log_operations gfs2_buf_lops = {
  	.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_before_commit = revoke_lo_before_commit,
  	.lo_after_commit = revoke_lo_after_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_name = "rg",
  };
  
  const struct gfs2_log_operations gfs2_databuf_lops = {
  	.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_databuf_lops,
  	&gfs2_buf_lops,
  	&gfs2_rg_lops,
  	&gfs2_revoke_lops,
  	NULL,
  };
  
  