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The ocfs2_read_dir_block() function really maps an inode's virtual blocks to physical ones before calling ocfs2_read_blocks(). Let's extract that to common code, because other places might want to do that. Other than the block number being virtual, ocfs2_read_virt_blocks() takes the same arguments as ocfs2_read_blocks(). It converts those virtual block numbers to physical before calling ocfs2_read_blocks() directly. If the blocks asked for are discontiguous, this can mean multiple calls to ocfs2_read_blocks(), but this is mostly hidden from the caller. Like ocfs2_read_blocks(), the caller can pass in an existing buffer_head. This is usually done to pick up some readahead I/O. ocfs2_read_virt_blocks() checks the buffer_head's block number against the extent map - it must match. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* extent_map.h
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*
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* In-memory file extent mappings for OCFS2.
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*
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* Copyright (C) 2004 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License, version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef _EXTENT_MAP_H
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#define _EXTENT_MAP_H
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struct ocfs2_extent_map_item {
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unsigned int ei_cpos;
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unsigned int ei_phys;
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unsigned int ei_clusters;
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unsigned int ei_flags;
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struct list_head ei_list;
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};
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#define OCFS2_MAX_EXTENT_MAP_ITEMS 3
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struct ocfs2_extent_map {
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unsigned int em_num_items;
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struct list_head em_list;
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};
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void ocfs2_extent_map_init(struct inode *inode);
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void ocfs2_extent_map_trunc(struct inode *inode, unsigned int cluster);
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void ocfs2_extent_map_insert_rec(struct inode *inode,
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struct ocfs2_extent_rec *rec);
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int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
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u32 *num_clusters, unsigned int *extent_flags);
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int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
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u64 *ret_count, unsigned int *extent_flags);
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int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
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u64 map_start, u64 map_len);
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int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
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u32 *p_cluster, u32 *num_clusters,
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struct ocfs2_extent_list *el);
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int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
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struct buffer_head *bhs[], int flags,
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int (*validate)(struct super_block *sb,
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struct buffer_head *bh));
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static inline int ocfs2_read_virt_block(struct inode *inode, u64 v_block,
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struct buffer_head **bh,
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int (*validate)(struct super_block *sb,
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struct buffer_head *bh))
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{
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int status = 0;
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if (bh == NULL) {
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printk("ocfs2: bh == NULL\n");
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status = -EINVAL;
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goto bail;
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}
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status = ocfs2_read_virt_blocks(inode, v_block, 1, bh, 0, validate);
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bail:
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return status;
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}
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#endif /* _EXTENT_MAP_H */
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