file-item.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 */

#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include "messages.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "bio.h"
#include "compression.h"
#include "fs.h"
#include "accessors.h"
#include "file-item.h"

#define __MAX_CSUM_ITEMS(r, size) …

#define MAX_CSUM_ITEMS(r, size) …

/*
 * Set inode's size according to filesystem options.
 *
 * @inode:      inode we want to update the disk_i_size for
 * @new_i_size: i_size we want to set to, 0 if we use i_size
 *
 * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
 * returns as it is perfectly fine with a file that has holes without hole file
 * extent items.
 *
 * However without NO_HOLES we need to only return the area that is contiguous
 * from the 0 offset of the file.  Otherwise we could end up adjust i_size up
 * to an extent that has a gap in between.
 *
 * Finally new_i_size should only be set in the case of truncate where we're not
 * ready to use i_size_read() as the limiter yet.
 */
void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size)
{ … }

/*
 * Mark range within a file as having a new extent inserted.
 *
 * @inode: inode being modified
 * @start: start file offset of the file extent we've inserted
 * @len:   logical length of the file extent item
 *
 * Call when we are inserting a new file extent where there was none before.
 * Does not need to call this in the case where we're replacing an existing file
 * extent, however if not sure it's fine to call this multiple times.
 *
 * The start and len must match the file extent item, so thus must be sectorsize
 * aligned.
 */
int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
				      u64 len)
{ … }

/*
 * Mark an inode range as not having a backing extent.
 *
 * @inode: inode being modified
 * @start: start file offset of the file extent we've inserted
 * @len:   logical length of the file extent item
 *
 * Called when we drop a file extent, for example when we truncate.  Doesn't
 * need to be called for cases where we're replacing a file extent, like when
 * we've COWed a file extent.
 *
 * The start and len must match the file extent item, so thus must be sectorsize
 * aligned.
 */
int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
					u64 len)
{ … }

static size_t bytes_to_csum_size(const struct btrfs_fs_info *fs_info, u32 bytes)
{ … }

static size_t csum_size_to_bytes(const struct btrfs_fs_info *fs_info, u32 csum_size)
{ … }

static inline u32 max_ordered_sum_bytes(const struct btrfs_fs_info *fs_info)
{ … }

/*
 * Calculate the total size needed to allocate for an ordered sum structure
 * spanning @bytes in the file.
 */
static int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info, unsigned long bytes)
{ … }

int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     u64 objectid, u64 pos, u64 num_bytes)
{ … }

static struct btrfs_csum_item *
btrfs_lookup_csum(struct btrfs_trans_handle *trans,
		  struct btrfs_root *root,
		  struct btrfs_path *path,
		  u64 bytenr, int cow)
{ … }

int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     struct btrfs_path *path, u64 objectid,
			     u64 offset, int mod)
{ … }

/*
 * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
 * store the result to @dst.
 *
 * Return >0 for the number of sectors we found.
 * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
 * for it. Caller may want to try next sector until one range is hit.
 * Return <0 for fatal error.
 */
static int search_csum_tree(struct btrfs_fs_info *fs_info,
			    struct btrfs_path *path, u64 disk_bytenr,
			    u64 len, u8 *dst)
{ … }

/*
 * Lookup the checksum for the read bio in csum tree.
 *
 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
 */
blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
{ … }

/*
 * Search for checksums for a given logical range.
 *
 * @root:		The root where to look for checksums.
 * @start:		Logical address of target checksum range.
 * @end:		End offset (inclusive) of the target checksum range.
 * @list:		List for adding each checksum that was found.
 *			Can be NULL in case the caller only wants to check if
 *			there any checksums for the range.
 * @nowait:		Indicate if the search must be non-blocking or not.
 *
 * Return < 0 on error, 0 if no checksums were found, or 1 if checksums were
 * found.
 */
int btrfs_lookup_csums_list(struct btrfs_root *root, u64 start, u64 end,
			    struct list_head *list, bool nowait)
{ … }

/*
 * Do the same work as btrfs_lookup_csums_list(), the difference is in how
 * we return the result.
 *
 * This version will set the corresponding bits in @csum_bitmap to represent
 * that there is a csum found.
 * Each bit represents a sector. Thus caller should ensure @csum_buf passed
 * in is large enough to contain all csums.
 */
int btrfs_lookup_csums_bitmap(struct btrfs_root *root, struct btrfs_path *path,
			      u64 start, u64 end, u8 *csum_buf,
			      unsigned long *csum_bitmap)
{ … }

/*
 * Calculate checksums of the data contained inside a bio.
 */
blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
{ … }

/*
 * Nodatasum I/O on zoned file systems still requires an btrfs_ordered_sum to
 * record the updated logical address on Zone Append completion.
 * Allocate just the structure with an empty sums array here for that case.
 */
blk_status_t btrfs_alloc_dummy_sum(struct btrfs_bio *bbio)
{ … }

/*
 * Remove one checksum overlapping a range.
 *
 * This expects the key to describe the csum pointed to by the path, and it
 * expects the csum to overlap the range [bytenr, len]
 *
 * The csum should not be entirely contained in the range and the range should
 * not be entirely contained in the csum.
 *
 * This calls btrfs_truncate_item with the correct args based on the overlap,
 * and fixes up the key as required.
 */
static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
				       struct btrfs_path *path,
				       struct btrfs_key *key,
				       u64 bytenr, u64 len)
{ … }

/*
 * Delete the csum items from the csum tree for a given range of bytes.
 */
int btrfs_del_csums(struct btrfs_trans_handle *trans,
		    struct btrfs_root *root, u64 bytenr, u64 len)
{ … }

static int find_next_csum_offset(struct btrfs_root *root,
				 struct btrfs_path *path,
				 u64 *next_offset)
{ … }

int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root,
			   struct btrfs_ordered_sum *sums)
{ … }

void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
				     const struct btrfs_path *path,
				     struct btrfs_file_extent_item *fi,
				     struct extent_map *em)
{ … }

/*
 * Returns the end offset (non inclusive) of the file extent item the given path
 * points to. If it points to an inline extent, the returned offset is rounded
 * up to the sector size.
 */
u64 btrfs_file_extent_end(const struct btrfs_path *path)
{ … }
linux/fs/btrfs/file-item.c
