extent_map.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0-only
/*
 * extent_map.c
 *
 * Block/Cluster mapping functions
 *
 * Copyright (C) 2004 Oracle.  All rights reserved.
 */

#include <linux/fs.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/fiemap.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "inode.h"
#include "super.h"
#include "symlink.h"
#include "aops.h"
#include "ocfs2_trace.h"

#include "buffer_head_io.h"

/*
 * The extent caching implementation is intentionally trivial.
 *
 * We only cache a small number of extents stored directly on the
 * inode, so linear order operations are acceptable. If we ever want
 * to increase the size of the extent map, then these algorithms must
 * get smarter.
 */

void ocfs2_extent_map_init(struct inode *inode)
{ … }

static void __ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
				      unsigned int cpos,
				      struct ocfs2_extent_map_item **ret_emi)
{ … }

static int ocfs2_extent_map_lookup(struct inode *inode, unsigned int cpos,
				   unsigned int *phys, unsigned int *len,
				   unsigned int *flags)
{ … }

/*
 * Forget about all clusters equal to or greater than cpos.
 */
void ocfs2_extent_map_trunc(struct inode *inode, unsigned int cpos)
{ … }

/*
 * Is any part of emi2 contained within emi1
 */
static int ocfs2_ei_is_contained(struct ocfs2_extent_map_item *emi1,
				 struct ocfs2_extent_map_item *emi2)
{ … }

static void ocfs2_copy_emi_fields(struct ocfs2_extent_map_item *dest,
				  struct ocfs2_extent_map_item *src)
{ … }

/*
 * Try to merge emi with ins. Returns 1 if merge succeeds, zero
 * otherwise.
 */
static int ocfs2_try_to_merge_extent_map(struct ocfs2_extent_map_item *emi,
					 struct ocfs2_extent_map_item *ins)
{ … }

/*
 * In order to reduce complexity on the caller, this insert function
 * is intentionally liberal in what it will accept.
 *
 * The only rule is that the truncate call *must* be used whenever
 * records have been deleted. This avoids inserting overlapping
 * records with different physical mappings.
 */
void ocfs2_extent_map_insert_rec(struct inode *inode,
				 struct ocfs2_extent_rec *rec)
{ … }

static int ocfs2_last_eb_is_empty(struct inode *inode,
				  struct ocfs2_dinode *di)
{ … }

/*
 * Return the 1st index within el which contains an extent start
 * larger than v_cluster.
 */
static int ocfs2_search_for_hole_index(struct ocfs2_extent_list *el,
				       u32 v_cluster)
{ … }

/*
 * Figure out the size of a hole which starts at v_cluster within the given
 * extent list.
 *
 * If there is no more allocation past v_cluster, we return the maximum
 * cluster size minus v_cluster.
 *
 * If we have in-inode extents, then el points to the dinode list and
 * eb_bh is NULL. Otherwise, eb_bh should point to the extent block
 * containing el.
 */
int ocfs2_figure_hole_clusters(struct ocfs2_caching_info *ci,
			       struct ocfs2_extent_list *el,
			       struct buffer_head *eb_bh,
			       u32 v_cluster,
			       u32 *num_clusters)
{ … }

static int ocfs2_get_clusters_nocache(struct inode *inode,
				      struct buffer_head *di_bh,
				      u32 v_cluster, unsigned int *hole_len,
				      struct ocfs2_extent_rec *ret_rec,
				      unsigned int *is_last)
{ … }

static void ocfs2_relative_extent_offsets(struct super_block *sb,
					  u32 v_cluster,
					  struct ocfs2_extent_rec *rec,
					  u32 *p_cluster, u32 *num_clusters)

{ … }

int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
			     u32 *p_cluster, u32 *num_clusters,
			     struct ocfs2_extent_list *el,
			     unsigned int *extent_flags)
{ … }

int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
		       u32 *p_cluster, u32 *num_clusters,
		       unsigned int *extent_flags)
{ … }

/*
 * This expects alloc_sem to be held. The allocation cannot change at
 * all while the map is in the process of being updated.
 */
int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
				u64 *ret_count, unsigned int *extent_flags)
{ … }

/*
 * The ocfs2_fiemap_inline() may be a little bit misleading, since
 * it not only handles the fiemap for inlined files, but also deals
 * with the fast symlink, cause they have no difference for extent
 * mapping per se.
 */
static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
			       struct fiemap_extent_info *fieinfo,
			       u64 map_start)
{ … }

int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		 u64 map_start, u64 map_len)
{ … }

/* Is IO overwriting allocated blocks? */
int ocfs2_overwrite_io(struct inode *inode, struct buffer_head *di_bh,
		       u64 map_start, u64 map_len)
{ … }

int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int whence)
{ … }

int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
			   struct buffer_head *bhs[], int flags,
			   int (*validate)(struct super_block *sb,
					   struct buffer_head *bh))
{ … }
linux/fs/ocfs2/extent_map.c
