C++ brelse函数代码示例

static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct gfs2_inode *dip = GFS2_I(dir), *ip;
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	struct gfs2_holder ghs[2];
	struct inode *inode;
	struct buffer_head *dibh;
	int error;

	gfs2_holder_init(dip->i_gl, 0, 0, ghs);

	inode = gfs2_createi(ghs, &dentry->d_name, S_IFDIR | mode, 0);
	if (IS_ERR(inode)) {
		gfs2_holder_uninit(ghs);
		return PTR_ERR(inode);
	}

	ip = ghs[1].gh_gl->gl_object;

	ip->i_inode.i_nlink = 2;
	ip->i_disksize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
	ip->i_diskflags |= GFS2_DIF_JDATA;
	ip->i_entries = 2;

	error = gfs2_meta_inode_buffer(ip, &dibh);

	if (!gfs2_assert_withdraw(sdp, !error)) {
		struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
		struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1);
		struct qstr str;

		gfs2_str2qstr(&str, ".");
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		gfs2_qstr2dirent(&str, GFS2_DIRENT_SIZE(str.len), dent);
		dent->de_inum = di->di_num; /* already GFS2 endian */
		dent->de_type = cpu_to_be16(DT_DIR);
		di->di_entries = cpu_to_be32(1);

		gfs2_str2qstr(&str, "..");
		dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
		gfs2_qstr2dirent(&str, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent);

		gfs2_inum_out(dip, dent);
		dent->de_type = cpu_to_be16(DT_DIR);

		gfs2_dinode_out(ip, di);

		brelse(dibh);
	}

	error = gfs2_change_nlink(dip, +1);
	gfs2_assert_withdraw(sdp, !error); /* dip already pinned */

	gfs2_trans_end(sdp);
	if (dip->i_alloc->al_rgd)
		gfs2_inplace_release(dip);
	gfs2_quota_unlock(dip);
	gfs2_alloc_put(dip);

	gfs2_glock_dq_uninit_m(2, ghs);

	d_instantiate(dentry, inode);
	mark_inode_dirty(inode);

	return 0;
}

//.........这里部分代码省略.........

	/* A directory block may not span across multiple I/O blocks.  */
	KASSERT(dirblksiz <= mp->mnt_stat.f_iosize);

	/* Find the bounds of the search.  */
	search_start = tulr->ulr_offset;
	KASSERT(fulr->ulr_reclen < (EXT2FS_MAXDIRSIZE - fulr->ulr_offset));
	search_end = (fulr->ulr_offset + fulr->ulr_reclen);

	/* Compaction must happen only within a directory block. (*)  */
	KASSERT(search_start <= search_end);
	KASSERT((search_end - (search_start &~ (dirblksiz - 1))) <= dirblksiz);

	dirbuf = NULL;
	bp = NULL;
	error = ext2fs_blkatoff(dvp, (off_t)search_start, &dirbuf, &bp);
	if (error)
		return error;
	KASSERT(dirbuf != NULL);
	KASSERT(bp != NULL);

	/*
	 * Guarantee we sha'n't go past the end of the buffer we got.
	 * dirbuf is bp->b_data + (search_start & (iosize - 1)), and
	 * the valid range is [bp->b_data, bp->b_data + bp->b_bcount).
	 */
	KASSERT((search_end - search_start) <=
	    (bp->b_bcount - (search_start & (mp->mnt_stat.f_iosize - 1))));

	prev_reclen = fulr->ulr_count;
	offset = search_start;

	/*
	 * Search from search_start to search_end for the entry matching
	 * fcnp, which must be there because we found it before and it
	 * should only at most have moved earlier.
	 */
	for (;;) {
		KASSERT(search_start <= offset);
		KASSERT(offset < search_end);

		/*
		 * Examine the directory entry at offset.
		 */
		ep = (struct ext2fs_direct *)
		    (dirbuf + (offset - search_start));
		reclen = fs2h16(ep->e2d_reclen);

		if (ep->e2d_ino == 0)
			goto next;	/* Entry is unused.  */

		if (fs2h32(ep->e2d_ino) == UFS_WINO)
			goto next;	/* Entry is whiteout.  */

		if (fcnp->cn_namelen != ep->e2d_namlen)
			goto next;	/* Wrong name length.  */

		if (memcmp(ep->e2d_name, fcnp->cn_nameptr, fcnp->cn_namelen))
			goto next;	/* Wrong name.  */

		/* Got it!  */
		break;

next:
		if (! ((reclen < search_end) &&
			(offset < (search_end - reclen)))) {
			brelse(bp, 0);
			return EIO;	/* XXX Panic?  What?  */
		}

		/* We may not move past the search end.  */
		KASSERT(reclen < search_end);
		KASSERT(offset < (search_end - reclen));

		/*
		 * We may not move across a directory block boundary;
		 * see (*) above.
		 */
		KASSERT((offset &~ (dirblksiz - 1)) ==
		    ((offset + reclen) &~ (dirblksiz - 1)));

		prev_reclen = reclen;
		offset += reclen;
	}

	/*
	 * Found the entry.  Record where.
	 */
	fulr->ulr_offset = offset;
	fulr->ulr_reclen = reclen;

	/*
	 * Record the preceding record length, but not if we're at the
	 * start of a directory block.
	 */
	fulr->ulr_count = ((offset & (dirblksiz - 1))? prev_reclen : 0);

	brelse(bp, 0);
	return 0;
}

static int gfs2_write_end(struct file *file, struct address_space *mapping,
			  loff_t pos, unsigned len, unsigned copied,
			  struct page *page, void *fsdata)
{
	struct inode *inode = page->mapping->host;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
	struct buffer_head *dibh;
	struct gfs2_qadata *qa = ip->i_qadata;
	unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
	unsigned int to = from + len;
	int ret;
	int i_size_changed = 0;

	BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);

	ret = gfs2_meta_inode_buffer(ip, &dibh);
	if (unlikely(ret)) {
		unlock_page(page);
		page_cache_release(page);
		goto failed;
	}

	gfs2_trans_add_bh(ip->i_gl, dibh, 1);

	if (gfs2_is_stuffed(ip))
		return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);

	if (!gfs2_is_writeback(ip))
		gfs2_page_add_databufs(ip, page, from, to);

	/* inlined bits of generic_write_end to avoid marking the inode dirty
	   a second time: */
	ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
	if (pos + ret > ip->i_disksize) {
		ip->i_disksize = pos + ret;
		i_size_write(inode, pos + ret);
		i_size_changed = 1;
	}

	unlock_page(page);
	page_cache_release(page);

	if (i_size_changed) {
		gfs2_dinode_out(ip, dibh->b_data);
		mark_inode_dirty(inode);
	}

	if (inode == sdp->sd_rindex) {
		adjust_fs_space(inode);
		sdp->sd_rindex_uptodate = 0;
	}

	brelse(dibh);
	gfs2_trans_end(sdp);
failed:
	if (ip->i_res)
		gfs2_inplace_release(ip);
	if (qa) {
		gfs2_quota_unlock(ip);
		gfs2_qadata_put(ip);
	}
	if (inode == sdp->sd_rindex) {
		gfs2_glock_dq(&m_ip->i_gh);
		gfs2_holder_uninit(&m_ip->i_gh);
	}
	gfs2_glock_dq(&ip->i_gh);
	gfs2_holder_uninit(&ip->i_gh);
	return ret;
}

static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
			      handle_t *handle,
			      u32 bits_wanted,
			      u32 min_bits,
			      u16 *bit_off,
			      unsigned int *num_bits,
			      u64 *bg_blkno,
			      u16 *bits_left)
{
	int status;
	u16 chain, tmp_bits;
	u32 tmp_used;
	u64 next_group;
	struct inode *alloc_inode = ac->ac_inode;
	struct buffer_head *group_bh = NULL;
	struct buffer_head *prev_group_bh = NULL;
	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
	struct ocfs2_group_desc *bg;

	chain = ac->ac_chain;
	mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
	     bits_wanted, chain,
	     (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);

	status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
				  le64_to_cpu(cl->cl_recs[chain].c_blkno),
				  &group_bh, OCFS2_BH_CACHED, alloc_inode);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	bg = (struct ocfs2_group_desc *) group_bh->b_data;
	status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
	if (status) {
		mlog_errno(status);
		goto bail;
	}

	status = -ENOSPC;
	/* for now, the chain search is a bit simplistic. We just use
	 * the 1st group with any empty bits. */
	while ((status = ac->ac_group_search(alloc_inode, group_bh,
					     bits_wanted, min_bits, bit_off,
					     &tmp_bits)) == -ENOSPC) {
		if (!bg->bg_next_group)
			break;

		if (prev_group_bh) {
			brelse(prev_group_bh);
			prev_group_bh = NULL;
		}
		next_group = le64_to_cpu(bg->bg_next_group);
		prev_group_bh = group_bh;
		group_bh = NULL;
		status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
					  next_group, &group_bh,
					  OCFS2_BH_CACHED, alloc_inode);
		if (status < 0) {
			mlog_errno(status);
			goto bail;
		}
		bg = (struct ocfs2_group_desc *) group_bh->b_data;
		status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
		if (status) {
			mlog_errno(status);
			goto bail;
		}
	}
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}

	mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
	     tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));

	*num_bits = tmp_bits;

	BUG_ON(*num_bits == 0);

	/*
	 * Keep track of previous block descriptor read. When
	 * we find a target, if we have read more than X
	 * number of descriptors, and the target is reasonably
	 * empty, relink him to top of his chain.
	 *
	 * We've read 0 extra blocks and only send one more to
	 * the transaction, yet the next guy to search has a
	 * much easier time.
	 *
	 * Do this *after* figuring out how many bits we're taking out
	 * of our target group.
	 */
	if (ac->ac_allow_chain_relink &&
	    (prev_group_bh) &&
	    (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
		status = ocfs2_relink_block_group(handle, alloc_inode,
						  ac->ac_bh, group_bh,
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		goto bail;
	}

	credits = ocfs2_calc_group_alloc_credits(osb->sb,
						 le16_to_cpu(cl->cl_cpg));
	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		handle = NULL;
		mlog_errno(status);
		goto bail;
	}

	status = ocfs2_claim_clusters(osb,
				      handle,
				      ac,
				      le16_to_cpu(cl->cl_cpg),
				      &bit_off,
				      &num_bits);
	if (status < 0) {
		if (status != -ENOSPC)
			mlog_errno(status);
		goto bail;
	}

	alloc_rec = ocfs2_find_smallest_chain(cl);

	/* setup the group */
	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
	mlog(0, "new descriptor, record %u, at block %llu\n",
	     alloc_rec, (unsigned long long)bg_blkno);

	bg_bh = sb_getblk(osb->sb, bg_blkno);
	if (!bg_bh) {
		status = -EIO;
		mlog_errno(status);
		goto bail;
	}
	ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);

	status = ocfs2_block_group_fill(handle,
					alloc_inode,
					bg_bh,
					bg_blkno,
					alloc_rec,
					cl);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	bg = (struct ocfs2_group_desc *) bg_bh->b_data;

	status = ocfs2_journal_access(handle, alloc_inode,
				      bh, OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
		     le16_to_cpu(bg->bg_free_bits_count));
	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
	cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
		le16_add_cpu(&cl->cl_next_free_rec, 1);

	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
					le16_to_cpu(bg->bg_free_bits_count));
	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));

	status = ocfs2_journal_dirty(handle, bh);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}

	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
					     le32_to_cpu(fe->i_clusters)));
	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);

	status = 0;
bail:
	if (handle)
		ocfs2_commit_trans(osb, handle);

	if (ac)
		ocfs2_free_alloc_context(ac);

	if (bg_bh)
		brelse(bg_bh);

	mlog_exit(status);
	return status;
}

static int
ext2_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
    daddr_t lastbn, int level, e4fs_daddr_t *countp)
{
	struct buf *bp;
	struct m_ext2fs *fs = ip->i_e2fs;
	struct vnode *vp;
	e2fs_daddr_t *bap, *copy;
	int i, nblocks, error = 0, allerror = 0;
	e2fs_lbn_t nb, nlbn, last;
	e4fs_daddr_t blkcount, factor, blocksreleased = 0;

	/*
	 * Calculate index in current block of last
	 * block to be kept.  -1 indicates the entire
	 * block so we need not calculate the index.
	 */
	factor = 1;
	for (i = SINGLE; i < level; i++)
		factor *= NINDIR(fs);
	last = lastbn;
	if (lastbn > 0)
		last /= factor;
	nblocks = btodb(fs->e2fs_bsize);
	/*
	 * Get buffer of block pointers, zero those entries corresponding
	 * to blocks to be free'd, and update on disk copy first.  Since
	 * double(triple) indirect before single(double) indirect, calls
	 * to bmap on these blocks will fail.  However, we already have
	 * the on disk address, so we have to set the b_blkno field
	 * explicitly instead of letting bread do everything for us.
	 */
	vp = ITOV(ip);
	bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0, 0);
	if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
		bp->b_iocmd = BIO_READ;
		if (bp->b_bcount > bp->b_bufsize)
			panic("ext2_indirtrunc: bad buffer size");
		bp->b_blkno = dbn;
		vfs_busy_pages(bp, 0);
		bp->b_iooffset = dbtob(bp->b_blkno);
		bstrategy(bp);
		error = bufwait(bp);
	}
	if (error) {
		brelse(bp);
		*countp = 0;
		return (error);
	}

	bap = (e2fs_daddr_t *)bp->b_data;
	copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK);
	bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->e2fs_bsize);
	bzero((caddr_t)&bap[last + 1],
	  (NINDIR(fs) - (last + 1)) * sizeof(e2fs_daddr_t));
	if (last == -1)
		bp->b_flags |= B_INVAL;
	if (DOINGASYNC(vp)) {
		bdwrite(bp);
	} else {
		error = bwrite(bp);
		if (error)
			allerror = error;
	}
	bap = copy;

	/*
	 * Recursively free totally unused blocks.
	 */
	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
	    i--, nlbn += factor) {
		nb = bap[i];
		if (nb == 0)
			continue;
		if (level > SINGLE) {
			if ((error = ext2_indirtrunc(ip, nlbn,
			    fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0)
				allerror = error;
			blocksreleased += blkcount;
		}
		ext2_blkfree(ip, nb, fs->e2fs_bsize);
		blocksreleased += nblocks;
	}

	/*
	 * Recursively free last partial block.
	 */
	if (level > SINGLE && lastbn >= 0) {
		last = lastbn % factor;
		nb = bap[i];
		if (nb != 0) {
			if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
			    last, level - 1, &blkcount)) != 0)
				allerror = error;
			blocksreleased += blkcount;
		}
	}
	free(copy, M_TEMP);
	*countp = blocksreleased;
	return (allerror);
//.........这里部分代码省略.........

/*
 *	isofs_find_entry()
 *
 * finds an entry in the specified directory with the wanted name. It
 * returns the inode number of the found entry, or 0 on error.
 */
static unsigned long
isofs_find_entry(struct inode *dir, struct dentry *dentry,
	unsigned long *block_rv, unsigned long *offset_rv,
	char *tmpname, struct iso_directory_record *tmpde)
{
	unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
	unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
	unsigned long block, f_pos, offset, block_saved, offset_saved;
	struct buffer_head *bh = NULL;
	struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb);

	if (!ISOFS_I(dir)->i_first_extent)
		return 0;

	f_pos = 0;
	offset = 0;
	block = 0;

	while (f_pos < dir->i_size) {
		struct iso_directory_record *de;
		int de_len, match, i, dlen;
		char *dpnt;

		if (!bh) {
			bh = isofs_bread(dir, block);
			if (!bh)
				return 0;
		}

		de = (struct iso_directory_record *) (bh->b_data + offset);

		de_len = *(unsigned char *) de;
		if (!de_len) {
			brelse(bh);
			bh = NULL;
			f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
			block = f_pos >> bufbits;
			offset = 0;
			continue;
		}

		block_saved = bh->b_blocknr;
		offset_saved = offset;
		offset += de_len;
		f_pos += de_len;

		/* Make sure we have a full directory entry */
		if (offset >= bufsize) {
			int slop = bufsize - offset + de_len;
			memcpy(tmpde, de, slop);
			offset &= bufsize - 1;
			block++;
			brelse(bh);
			bh = NULL;
			if (offset) {
				bh = isofs_bread(dir, block);
				if (!bh)
					return 0;
				memcpy((void *) tmpde + slop, bh->b_data, offset);
			}
			de = tmpde;
		}

		dlen = de->name_len[0];
		dpnt = de->name;
		/* Basic sanity check, whether name doesn't exceed dir entry */
		if (de_len < dlen + sizeof(struct iso_directory_record)) {
			printk(KERN_NOTICE "iso9660: Corrupted directory entry"
			       " in block %lu of inode %lu\n", block,
			       dir->i_ino);
			return 0;
		}

		if (sbi->s_rock &&
		    ((i = get_rock_ridge_filename(de, tmpname, dir)))) {
			dlen = i;	/* possibly -1 */
			dpnt = tmpname;
#ifdef CONFIG_JOLIET
		} else if (sbi->s_joliet_level) {
			dlen = get_joliet_filename(de, tmpname, dir);
			dpnt = tmpname;
#endif
		} else if (sbi->s_mapping == 'a') {
			dlen = get_acorn_filename(de, tmpname, dir);
			dpnt = tmpname;
		} else if (sbi->s_mapping == 'n') {
			dlen = isofs_name_translate(de, tmpname, dir);
			dpnt = tmpname;
		}

		/*
		 * Skip hidden or associated files unless hide or showassoc,
		 * respectively, is set
		 */
//.........这里部分代码省略.........

static int simplefs_fill_super(struct super_block *sb, void *data, int silent) {
	struct buffer_head *bh;
	struct simplefs_super *rsb;
	struct simplefs_super_info *sbi;
	struct inode *root;
	int i, j, cnt, ret = 0;

	printk(KERN_INFO "simplefs_fill_super\n");
	if (!(bh = sb_bread(sb, SIMPLEFS_SUPER_BNO))) {
		printk(KERN_ERR "Simplefs: unable to read superblock\n");
		return -ENOMEM;
	}
	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
	if (!sbi) {
		ret = -ENOMEM;
		goto out;
	}
	sbi->s_sb = bh;
	memcpy(&sbi->raw_super, bh->b_data, sizeof(sbi->raw_super));
	sb->s_fs_info = sbi;
	sb->s_blocksize = SIMPLEFS_BLOCKSIZE;
	sb->s_flags = sb->s_flags & ~MS_POSIXACL;

	/*
	 * set up enough so that it can read an inode
	 */
	sb->s_op = &simplefs_super_operations;
	root = simplefs_iget(sb, SIMPLEFS_ROOT_INO);
	if (!root) {
		printk(KERN_ERR "Simplefs: corrupt root inode\n");
		ret = -EINVAL;
		goto failed_root;
	}
	printk(KERN_INFO "simplefs_fill_super -> simplefs_iget ok: %ld\n", root->i_ino);
	
	sb->s_root = d_alloc_root(root);
	if (!sb->s_root) {
		iput(root);
		printk(KERN_ERR "Simplefs: get root dentry failed\n");
		ret = -ENOMEM;
		goto failed_root;
	}
	printk(KERN_INFO "simplefs_fill_super -> d_alloc_root ok\n");

	
	cnt = sbi->raw_super.s_inode_bitmap_blknr + sbi->raw_super.s_block_bitmap_blknr;
	if (!(sbi->s_bitmaps = kzalloc(sizeof(struct buffer_head *) * cnt, GFP_KERNEL)))
		goto failed_bitmap;
	for (i = 0, j = 0; i < cnt; i++) {
		if (!(bh = bitmap_load(sb, SIMPLEFS_SUPER_BNO + 1 + i)))
			goto failed_load;
		sbi->s_bitmaps[j++] = bh;
		printk(KERN_INFO "simplefs_fill_super bitmap ok:%d -> %d\n", cnt, i);
	}
	rsb = &sbi->raw_super;
	printk("fill super ok: (inode %d %d %d) (block %d %d %d)\n",
	       rsb->s_inode_bitmap_blknr, rsb->s_inode_blknr, rsb->s_free_inodes_count,
	       rsb->s_block_bitmap_blknr, rsb->s_block_blknr, rsb->s_free_blocks_count);
	return 0;
 failed_load:
	for (i = 0; i < j; i++) {
		brelse(sbi->s_bitmaps[i]);
	}
 failed_bitmap:
	dput(sb->s_root);
 failed_root:
	kfree(sbi);
 out:
	brelse(bh);
	sbi->s_sb = NULL;
	printk("simplefs get sb failed.\n");
	return ret;
}

static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
		     struct dentry *dentry)
{
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	struct inode *inode = old_dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder ghs[2];
	struct buffer_head *dibh;
	int alloc_required;
	int error;

	if (S_ISDIR(inode->i_mode))
		return -EPERM;

	error = gfs2_rs_alloc(dip);
	if (error)
		return error;

	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

	error = gfs2_glock_nq(ghs); /* parent */
	if (error)
		goto out_parent;

	error = gfs2_glock_nq(ghs + 1); /* child */
	if (error)
		goto out_child;

	error = -ENOENT;
	if (inode->i_nlink == 0)
		goto out_gunlock;

	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
	if (error)
		goto out_gunlock;

	error = gfs2_dir_check(dir, &dentry->d_name, NULL);
	switch (error) {
	case -ENOENT:
		break;
	case 0:
		error = -EEXIST;
	default:
		goto out_gunlock;
	}

	error = -EINVAL;
	if (!dip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EFBIG;
	if (dip->i_entries == (u32)-1)
		goto out_gunlock;
	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
		goto out_gunlock;
	error = -EINVAL;
	if (!ip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EMLINK;
	if (ip->i_inode.i_nlink == (u32)-1)
		goto out_gunlock;

	alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name);
	if (error < 0)
		goto out_gunlock;
	error = 0;

	if (alloc_required) {
		error = gfs2_quota_lock_check(dip);
		if (error)
			goto out_gunlock;

		error = gfs2_inplace_reserve(dip, sdp->sd_max_dirres, 0);
		if (error)
			goto out_gunlock_q;

		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
					 gfs2_rg_blocks(dip, sdp->sd_max_dirres) +
					 2 * RES_DINODE + RES_STATFS +
					 RES_QUOTA, 0);
		if (error)
			goto out_ipres;
	} else {
		error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
		if (error)
			goto out_ipres;
	}

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error)
		goto out_end_trans;

	error = gfs2_dir_add(dir, &dentry->d_name, ip);
	if (error)
		goto out_brelse;

	gfs2_trans_add_meta(ip->i_gl, dibh);
	inc_nlink(&ip->i_inode);
//.........这里部分代码省略.........

static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
{
	struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
	struct nilfs_cpfile_header *header;
	struct nilfs_checkpoint *cp;
	struct nilfs_snapshot_list *list;
	__u64 next, prev;
	void *kaddr;
	int ret;

	if (cno == 0)
		return -ENOENT; 
	down_write(&NILFS_MDT(cpfile)->mi_sem);

	ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
	if (ret < 0)
		goto out_sem;
	kaddr = kmap_atomic(cp_bh->b_page);
	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
	if (nilfs_checkpoint_invalid(cp)) {
		ret = -ENOENT;
		kunmap_atomic(kaddr);
		goto out_cp;
	}
	if (!nilfs_checkpoint_snapshot(cp)) {
		ret = 0;
		kunmap_atomic(kaddr);
		goto out_cp;
	}

	list = &cp->cp_snapshot_list;
	next = le64_to_cpu(list->ssl_next);
	prev = le64_to_cpu(list->ssl_prev);
	kunmap_atomic(kaddr);

	ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
	if (ret < 0)
		goto out_cp;
	if (next != 0) {
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
							&next_bh);
		if (ret < 0)
			goto out_header;
	} else {
		next_bh = header_bh;
		get_bh(next_bh);
	}
	if (prev != 0) {
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
							&prev_bh);
		if (ret < 0)
			goto out_next;
	} else {
		prev_bh = header_bh;
		get_bh(prev_bh);
	}

	kaddr = kmap_atomic(next_bh->b_page);
	list = nilfs_cpfile_block_get_snapshot_list(
		cpfile, next, next_bh, kaddr);
	list->ssl_prev = cpu_to_le64(prev);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(prev_bh->b_page);
	list = nilfs_cpfile_block_get_snapshot_list(
		cpfile, prev, prev_bh, kaddr);
	list->ssl_next = cpu_to_le64(next);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(cp_bh->b_page);
	cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
	cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
	cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
	nilfs_checkpoint_clear_snapshot(cp);
	kunmap_atomic(kaddr);

	kaddr = kmap_atomic(header_bh->b_page);
	header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
	le64_add_cpu(&header->ch_nsnapshots, -1);
	kunmap_atomic(kaddr);

	mark_buffer_dirty(next_bh);
	mark_buffer_dirty(prev_bh);
	mark_buffer_dirty(cp_bh);
	mark_buffer_dirty(header_bh);
	nilfs_mdt_mark_dirty(cpfile);

	brelse(prev_bh);

 out_next:
	brelse(next_bh);

 out_header:
	brelse(header_bh);

 out_cp:
	brelse(cp_bh);

 out_sem:
	up_write(&NILFS_MDT(cpfile)->mi_sem);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
		err = PTR_ERR(sbi->node_inode);
		goto free_nm;
	}

	/* if there are nt orphan nodes free them */
	recover_orphan_inodes(sbi);

	/* read root inode and dentry */
	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
	if (IS_ERR(root)) {
		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
		err = PTR_ERR(root);
		goto free_node_inode;
	}
	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
		err = -EINVAL;
		goto free_root_inode;
	}

	sb->s_root = d_make_root(root); /* allocate root dentry */
	if (!sb->s_root) {
		err = -ENOMEM;
		goto free_root_inode;
	}

	err = f2fs_build_stats(sbi);
	if (err)
		goto free_root_inode;

	if (f2fs_proc_root)
		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);

	if (sbi->s_proc)
		proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
				 &f2fs_seq_segment_info_fops, sb);

	if (test_opt(sbi, DISCARD)) {
		struct request_queue *q = bdev_get_queue(sb->s_bdev);
		if (!blk_queue_discard(q))
			f2fs_msg(sb, KERN_WARNING,
					"mounting with \"discard\" option, but "
					"the device does not support discard");
	}

	sbi->s_kobj.kset = f2fs_kset;
	init_completion(&sbi->s_kobj_unregister);
	err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
							"%s", sb->s_id);
	if (err)
		goto free_proc;

	/* recover fsynced data */
	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
		err = recover_fsync_data(sbi);
		if (err)
			f2fs_msg(sb, KERN_ERR,
				"Cannot recover all fsync data errno=%ld", err);
	}

	/*
	 * If filesystem is not mounted as read-only then
	 * do start the gc_thread.
	 */
	if (!(sb->s_flags & MS_RDONLY)) {
		/* After POR, we can run background GC thread.*/
		err = start_gc_thread(sbi);
		if (err)
			goto free_kobj;
	}
	return 0;

free_kobj:
	kobject_del(&sbi->s_kobj);
free_proc:
	if (sbi->s_proc) {
		remove_proc_entry("segment_info", sbi->s_proc);
		remove_proc_entry(sb->s_id, f2fs_proc_root);
	}
	f2fs_destroy_stats(sbi);
free_root_inode:
	dput(sb->s_root);
	sb->s_root = NULL;
free_node_inode:
	iput(sbi->node_inode);
free_nm:
	destroy_node_manager(sbi);
free_sm:
	destroy_segment_manager(sbi);
free_cp:
	kfree(sbi->ckpt);
free_meta_inode:
	make_bad_inode(sbi->meta_inode);
	iput(sbi->meta_inode);
free_sb_buf:
	brelse(raw_super_buf);
free_sbi:
	kfree(sbi);
	return err;
}

/*
 * Write disk label back to device after modification.
 */
static int
l32_writedisklabel(cdev_t dev, struct diskslices *ssp, struct diskslice *sp,
		   disklabel_t lpx)
{
	struct disklabel32 *lp;
	struct disklabel32 *dlp;
	struct buf *bp;
	const char *msg;
	int error = 0;

	lp = lpx.lab32;

	if (lp->d_partitions[RAW_PART].p_offset != 0)
		return (EXDEV);			/* not quite right */

	bp = geteblk((int)lp->d_secsize);
	bp->b_bio1.bio_offset = (off_t)LABELSECTOR32 * lp->d_secsize;
	bp->b_bio1.bio_done = biodone_sync;
	bp->b_bio1.bio_flags |= BIO_SYNC;
	bp->b_bcount = lp->d_secsize;

#if 1
	/*
	 * We read the label first to see if it's there,
	 * in which case we will put ours at the same offset into the block..
	 * (I think this is stupid [Julian])
	 * Note that you can't write a label out over a corrupted label!
	 * (also stupid.. how do you write the first one? by raw writes?)
	 */
	bp->b_flags &= ~B_INVAL;
	bp->b_cmd = BUF_CMD_READ;
	KKASSERT(dkpart(dev) == WHOLE_SLICE_PART);
	dev_dstrategy(dev, &bp->b_bio1);
	error = biowait(&bp->b_bio1, "labrd");
	if (error)
		goto done;
	for (dlp = (struct disklabel32 *)bp->b_data;
	    dlp <= (struct disklabel32 *)
	      ((char *)bp->b_data + lp->d_secsize - sizeof(*dlp));
	    dlp = (struct disklabel32 *)((char *)dlp + sizeof(long))) {
		if (dlp->d_magic == DISKMAGIC32 &&
		    dlp->d_magic2 == DISKMAGIC32 && dkcksum32(dlp) == 0) {
			*dlp = *lp;
			lpx.lab32 = dlp;
			msg = l32_fixlabel(NULL, sp, lpx, TRUE);
			if (msg) {
				error = EINVAL;
			} else {
				bp->b_cmd = BUF_CMD_WRITE;
				bp->b_bio1.bio_done = biodone_sync;
				bp->b_bio1.bio_flags |= BIO_SYNC;
				KKASSERT(dkpart(dev) == WHOLE_SLICE_PART);
				dev_dstrategy(dev, &bp->b_bio1);
				error = biowait(&bp->b_bio1, "labwr");
			}
			goto done;
		}
	}
	error = ESRCH;
done:
#else
	bzero(bp->b_data, lp->d_secsize);
	dlp = (struct disklabel32 *)bp->b_data;
	*dlp = *lp;
	bp->b_flags &= ~B_INVAL;
	bp->b_cmd = BUF_CMD_WRITE;
	bp->b_bio1.bio_done = biodone_sync;
	bp->b_bio1.bio_flags |= BIO_SYNC;
	BUF_STRATEGY(bp, 1);
	error = biowait(&bp->b_bio1, "labwr");
#endif
	bp->b_flags |= B_INVAL | B_AGE;
	brelse(bp);
	return (error);
}

//.........这里部分代码省略.........
		goto finished;

	if (p->dir_type == LIF_DIR_HPLBL) {
		struct hpux_label *hl;
		struct partition *pp;
		u_int8_t fstype;
		int i;

		/* read LIF directory */
		dbp->b_blkno = lifstodb(p->dir_addr);
		dbp->b_bcount = lp->d_secsize;
		CLR(dbp->b_flags, B_READ | B_WRITE | B_DONE);
		SET(dbp->b_flags, B_BUSY | B_READ | B_RAW);
		(*strat)(dbp);

		if (biowait(dbp)) {
			error = dbp->b_error;
			goto done;
		}

		hl = (struct hpux_label *)dbp->b_data;
		if (hl->hl_magic1 != hl->hl_magic2 ||
		    hl->hl_magic != HPUX_MAGIC || hl->hl_version != 1) {
			error = EINVAL;	 /* HPUX label magic mismatch */
			goto done;
		}

		lp->d_bbsize = 8192;
		lp->d_sbsize = 8192;
		for (i = 0; i < MAXPARTITIONS; i++) {
			DL_SETPSIZE(&lp->d_partitions[i], 0);
			DL_SETPOFFSET(&lp->d_partitions[i], 0);
			lp->d_partitions[i].p_fstype = 0;
		}

		for (i = 0; i < HPUX_MAXPART; i++) {
			if (!hl->hl_flags[i])
				continue;
			if (hl->hl_flags[i] == HPUX_PART_ROOT) {
				pp = &lp->d_partitions[0];
				fstype = FS_BSDFFS;
			} else if (hl->hl_flags[i] == HPUX_PART_SWAP) {
				pp = &lp->d_partitions[1];
				fstype = FS_SWAP;
			} else if (hl->hl_flags[i] == HPUX_PART_BOOT) {
				pp = &lp->d_partitions[RAW_PART + 1];
				fstype = FS_BSDFFS;
			} else
				continue;

			DL_SETPSIZE(pp, hl->hl_parts[i].hlp_length * 2);
			DL_SETPOFFSET(pp, hl->hl_parts[i].hlp_start * 2);
			pp->p_fstype = fstype;
		}

		DL_SETPSIZE(&lp->d_partitions[RAW_PART], DL_GETDSIZE(lp));
		DL_SETPOFFSET(&lp->d_partitions[RAW_PART], 0);
		lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
		lp->d_npartitions = MAXPARTITIONS;
		lp->d_magic = DISKMAGIC;
		lp->d_magic2 = DISKMAGIC;
		lp->d_version = 1;
		lp->d_checksum = 0;
		lp->d_checksum = dkcksum(lp);
		/* drop through */
	}

finished:
	/* record the OpenBSD partition's placement for the caller */
	if (partoffp)
		*partoffp = fsoff;
	else {
		DL_SETBSTART(lp, openbsdstart);
		DL_SETBEND(lp, DL_GETDSIZE(lp));	/* XXX */
	}

	/* don't read the on-disk label if we are in spoofed-only mode */
	if (spoofonly)
		goto done;

	bp->b_blkno = fsoff + LABELSECTOR;
	bp->b_bcount = lp->d_secsize;
	CLR(bp->b_flags, B_READ | B_WRITE | B_DONE);
	SET(bp->b_flags, B_BUSY | B_READ | B_RAW);
	(*strat)(bp);
	if (biowait(bp)) {
		error = bp->b_error;
		goto done;
	}

	error = checkdisklabel(bp->b_data + LABELOFFSET, lp, openbsdstart,
	    DL_GETDSIZE(lp));	/* XXX */

done:
	if (dbp) {
		dbp->b_flags |= B_INVAL;
		brelse(dbp);
	}
	return (error);
}

int
hpfs_removedirent (
	struct hpfsmount *hpmp,
	lsn_t lsn,
	char *name,
	int namelen,
	int *retp)
{
#if 0
	struct buf *bp;
	dirblk_t *dbp;
	struct hpfsdirent *dep;
	int deoff;
	int error, ret;

	dprintf(("hpfs_removedirent(0x%x, %.*s, %d): \n",
		 lsn, namelen, name, namelen));

	error = hpfs_breaddirblk (hpmp, lsn, &bp);
	if (error)
		return (error);

	dbp = (dirblk_t *) bp->b_data;
	deoff = sizeof(dirblk_t);
	dep = DB_DIRENT(dbp);

	while(!(dep->de_flag & DE_END)) {
		dprintf(("no: 0x%x, size: %d, name: %2d:%.*s, flag: 0x%x\n",
			dep->de_fnode, dep->de_size, dep->de_namelen,
			dep->de_namelen, dep->de_name, dep->de_flag));

		res = hpfs_cmpfname(hpmp, name, namelen,
				dep->de_name, dep->de_namelen, dep->de_cpid);
		if (res == 0) {
			if (dep->de_flag & DE_DOWN) {
				/*XXXXXX*/
			} else {
				/* XXX we can copy less */
				bcopy (DE_NEXTDE(dep), dep, DB_BSIZE - deoff - dep->de_reclen);
				dbp->d_freeoff -= dep->de_reclen;
				*retp = 0;
			}
			bdwrite (bp);
			return (0);
		} else if (res < 0)
			break;

		deoff += dep->de_reclen;
		dep = DB_NEXTDE(dep);
	}

	if (dep->de_flag & DE_DOWN) {
		error = hpfs_removede (hpmp, DE_DOWNLSN(dep), name, namelen, &ret);
		if (error) {
			brelse (bp);
			return (error);
		}
		if (ret == 0) {
			if (deoff > sizeof (dirblk_t)) {
			} else if (deoff + dep->de_reclen < dbp->db_freeoff) {
			}
		}
	} else {
		error = ENOENT;
	}

	brelse (bp);
	return (error);
#endif
	return (EOPNOTSUPP);
}

void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno,
				 struct buffer_head *bh)
{
	kunmap(bh->b_page);
	brelse(bh);
}