^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * linux/fs/befs/datastream.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Based on portions of file.c by Makoto Kato <m_kato@ga2.so-net.ne.jp>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Many thanks to Dominic Giampaolo, author of "Practical File System
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Design with the Be File System", for such a helpful book.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include "befs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include "datastream.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include "io.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) const befs_inode_addr BAD_IADDR = { 0, 0, 0 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) static int befs_find_brun_direct(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) befs_blocknr_t blockno, befs_block_run *run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static int befs_find_brun_indirect(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) befs_blocknr_t blockno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) befs_block_run *run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) static int befs_find_brun_dblindirect(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) befs_blocknr_t blockno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) befs_block_run *run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * befs_read_datastream - get buffer_head containing data, starting from pos.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * @sb: Filesystem superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * @ds: datastream to find data with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * @pos: start of data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * @off: offset of data in buffer_head->b_data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * Returns pointer to buffer_head containing data starting with offset @off,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * if you don't need to know offset just set @off = NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct buffer_head *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) befs_read_datastream(struct super_block *sb, const befs_data_stream *ds,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) befs_off_t pos, uint *off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) befs_block_run run;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) befs_blocknr_t block; /* block coresponding to pos */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) befs_debug(sb, "---> %s %llu", __func__, pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) block = pos >> BEFS_SB(sb)->block_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) if (off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) *off = pos - (block << BEFS_SB(sb)->block_shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if (befs_fblock2brun(sb, ds, block, &run) != BEFS_OK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) befs_error(sb, "BeFS: Error finding disk addr of block %lu",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) (unsigned long)block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) befs_debug(sb, "<--- %s ERROR", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) bh = befs_bread_iaddr(sb, run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if (!bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) befs_error(sb, "BeFS: Error reading block %lu from datastream",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) (unsigned long)block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) befs_debug(sb, "<--- %s read data, starting at %llu", __func__, pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * befs_fblock2brun - give back block run for fblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * @sb: the superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * @data: datastream to read from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * @fblock: the blocknumber with the file position to find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * @run: The found run is passed back through this pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * Takes a file position and gives back a brun who's starting block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * is block number fblock of the file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * Returns BEFS_OK or BEFS_ERR.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * Calls specialized functions for each of the three possible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * datastream regions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) befs_fblock2brun(struct super_block *sb, const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) befs_blocknr_t fblock, befs_block_run *run)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) befs_off_t pos = fblock << BEFS_SB(sb)->block_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) if (pos < data->max_direct_range) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) err = befs_find_brun_direct(sb, data, fblock, run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) } else if (pos < data->max_indirect_range) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) err = befs_find_brun_indirect(sb, data, fblock, run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) } else if (pos < data->max_double_indirect_range) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) err = befs_find_brun_dblindirect(sb, data, fblock, run);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) befs_error(sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) "befs_fblock2brun() was asked to find block %lu, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) "which is not mapped by the datastream\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) (unsigned long)fblock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) err = BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * befs_read_lsmylink - read long symlink from datastream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * @sb: Filesystem superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * @ds: Datastream to read from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * @buff: Buffer in which to place long symlink data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * @len: Length of the long symlink in bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * Returns the number of bytes read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) size_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) befs_read_lsymlink(struct super_block *sb, const befs_data_stream *ds,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) void *buff, befs_off_t len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) befs_off_t bytes_read = 0; /* bytes readed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) u16 plen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) befs_debug(sb, "---> %s length: %llu", __func__, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) while (bytes_read < len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) bh = befs_read_datastream(sb, ds, bytes_read, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (!bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) befs_error(sb, "BeFS: Error reading datastream block "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) "starting from %llu", bytes_read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) befs_debug(sb, "<--- %s ERROR", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return bytes_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) plen = ((bytes_read + BEFS_SB(sb)->block_size) < len) ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) BEFS_SB(sb)->block_size : len - bytes_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) memcpy(buff + bytes_read, bh->b_data, plen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) bytes_read += plen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) befs_debug(sb, "<--- %s read %u bytes", __func__, (unsigned int)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) bytes_read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return bytes_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * befs_count_blocks - blocks used by a file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) * @sb: Filesystem superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * @ds: Datastream of the file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * Counts the number of fs blocks that the file represented by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * inode occupies on the filesystem, counting both regular file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * data and filesystem metadata (and eventually attribute data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * when we support attributes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) befs_blocknr_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) befs_count_blocks(struct super_block *sb, const befs_data_stream *ds)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) befs_blocknr_t blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) befs_blocknr_t datablocks; /* File data blocks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) befs_blocknr_t metablocks; /* FS metadata blocks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) struct befs_sb_info *befs_sb = BEFS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) befs_debug(sb, "---> %s", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) datablocks = ds->size >> befs_sb->block_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (ds->size & (befs_sb->block_size - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) datablocks += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) metablocks = 1; /* Start with 1 block for inode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /* Size of indirect block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) if (ds->size > ds->max_direct_range)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) metablocks += ds->indirect.len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) * Double indir block, plus all the indirect blocks it maps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * In the double-indirect range, all block runs of data are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) * BEFS_DBLINDIR_BRUN_LEN blocks long. Therefore, we know
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * how many data block runs are in the double-indirect region,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * and from that we know how many indirect blocks it takes to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * map them. We assume that the indirect blocks are also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * BEFS_DBLINDIR_BRUN_LEN blocks long.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) if (ds->size > ds->max_indirect_range && ds->max_indirect_range != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) uint dbl_bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) uint dbl_bruns;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) uint indirblocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) dbl_bytes =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) ds->max_double_indirect_range - ds->max_indirect_range;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) dbl_bruns =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) dbl_bytes / (befs_sb->block_size * BEFS_DBLINDIR_BRUN_LEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) indirblocks = dbl_bruns / befs_iaddrs_per_block(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) metablocks += ds->double_indirect.len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) metablocks += indirblocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) blocks = datablocks + metablocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) befs_debug(sb, "<--- %s %u blocks", __func__, (unsigned int)blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) return blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) * befs_find_brun_direct - find a direct block run in the datastream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) * @sb: the superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) * @data: the datastream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) * @blockno: the blocknumber to find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) * @run: The found run is passed back through this pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) * Finds the block run that starts at file block number blockno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) * in the file represented by the datastream data, if that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) * blockno is in the direct region of the datastream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * Return value is BEFS_OK if the blockrun is found, BEFS_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) * otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) * Algorithm:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) * Linear search. Checks each element of array[] to see if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) * contains the blockno-th filesystem block. This is necessary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) * because the block runs map variable amounts of data. Simply
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) * keeps a count of the number of blocks searched so far (sum),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) * incrementing this by the length of each block run as we come
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) * across it. Adds sum to *count before returning (this is so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) * you can search multiple arrays that are logicaly one array,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) * as in the indirect region code).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) * When/if blockno is found, if blockno is inside of a block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) * run as stored on disk, we offset the start and length members
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) * of the block run, so that blockno is the start and len is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) * still valid (the run ends in the same place).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) befs_blocknr_t blockno, befs_block_run *run)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) const befs_block_run *array = data->direct;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) befs_blocknr_t sum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) befs_debug(sb, "---> %s, find %lu", __func__, (unsigned long)blockno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) for (i = 0, sum = 0; i < BEFS_NUM_DIRECT_BLOCKS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) sum += array[i].len, i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) if (blockno >= sum && blockno < sum + (array[i].len)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) int offset = blockno - sum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) run->allocation_group = array[i].allocation_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) run->start = array[i].start + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) run->len = array[i].len - offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) befs_debug(sb, "---> %s, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) "found %lu at direct[%d]", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) (unsigned long)blockno, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) return BEFS_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) befs_error(sb, "%s failed to find file block %lu", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) (unsigned long)blockno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) befs_debug(sb, "---> %s ERROR", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * befs_find_brun_indirect - find a block run in the datastream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * @sb: the superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * @data: the datastream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * @blockno: the blocknumber to find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * @run: The found run is passed back through this pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * Finds the block run that starts at file block number blockno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * in the file represented by the datastream data, if that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * blockno is in the indirect region of the datastream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * Return value is BEFS_OK if the blockrun is found, BEFS_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * Algorithm:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) * For each block in the indirect run of the datastream, read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * it in and search through it for search_blk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * XXX:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * Really should check to make sure blockno is inside indirect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * region.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) befs_find_brun_indirect(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) befs_blocknr_t blockno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) befs_block_run *run)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) befs_blocknr_t sum = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) befs_blocknr_t indir_start_blk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) befs_blocknr_t search_blk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) struct buffer_head *indirblock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) befs_disk_block_run *array;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) befs_block_run indirect = data->indirect;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) befs_blocknr_t indirblockno = iaddr2blockno(sb, &indirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) int arraylen = befs_iaddrs_per_block(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) befs_debug(sb, "---> %s, find %lu", __func__, (unsigned long)blockno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) indir_start_blk = data->max_direct_range >> BEFS_SB(sb)->block_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) search_blk = blockno - indir_start_blk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) /* Examine blocks of the indirect run one at a time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) for (i = 0; i < indirect.len; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) indirblock = sb_bread(sb, indirblockno + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) if (indirblock == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) befs_error(sb, "---> %s failed to read "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) "disk block %lu from the indirect brun",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) __func__, (unsigned long)indirblockno + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) befs_debug(sb, "<--- %s ERROR", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) array = (befs_disk_block_run *) indirblock->b_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) for (j = 0; j < arraylen; ++j) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) int len = fs16_to_cpu(sb, array[j].len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) if (search_blk >= sum && search_blk < sum + len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) int offset = search_blk - sum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) run->allocation_group =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) fs32_to_cpu(sb, array[j].allocation_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) run->start =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) fs16_to_cpu(sb, array[j].start) + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) run->len =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) fs16_to_cpu(sb, array[j].len) - offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) brelse(indirblock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) befs_debug(sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) "<--- %s found file block "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) "%lu at indirect[%d]", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) (unsigned long)blockno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) j + (i * arraylen));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) return BEFS_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) sum += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) brelse(indirblock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) /* Only fallthrough is an error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) befs_error(sb, "BeFS: %s failed to find "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) "file block %lu", __func__, (unsigned long)blockno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) befs_debug(sb, "<--- %s ERROR", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * befs_find_brun_dblindirect - find a block run in the datastream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * @sb: the superblock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * @data: the datastream
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) * @blockno: the blocknumber to find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) * @run: The found run is passed back through this pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) * Finds the block run that starts at file block number blockno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * in the file represented by the datastream data, if that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * blockno is in the double-indirect region of the datastream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) * Return value is BEFS_OK if the blockrun is found, BEFS_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) * otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) * Algorithm:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) * The block runs in the double-indirect region are different.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) * They are always allocated 4 fs blocks at a time, so each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) * block run maps a constant amount of file data. This means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) * that we can directly calculate how many block runs into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) * double-indirect region we need to go to get to the one that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) * maps a particular filesystem block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * We do this in two stages. First we calculate which of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) * inode addresses in the double-indirect block will point us
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) * to the indirect block that contains the mapping for the data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) * then we calculate which of the inode addresses in that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) * indirect block maps the data block we are after.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * Oh, and once we've done that, we actually read in the blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * that contain the inode addresses we calculated above. Even
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) * though the double-indirect run may be several blocks long,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) * we can calculate which of those blocks will contain the index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * we are after and only read that one. We then follow it to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * the indirect block and perform a similar process to find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * the actual block run that maps the data block we are interested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * in.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * Then we offset the run as in befs_find_brun_array() and we are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) * done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) befs_find_brun_dblindirect(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) const befs_data_stream *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) befs_blocknr_t blockno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) befs_block_run *run)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) int dblindir_indx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) int indir_indx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) int dbl_which_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) int which_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) int dbl_block_indx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) int block_indx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) off_t dblindir_leftover;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) befs_blocknr_t blockno_at_run_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) struct buffer_head *dbl_indir_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) struct buffer_head *indir_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) befs_block_run indir_run;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) befs_disk_inode_addr *iaddr_array;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) befs_blocknr_t indir_start_blk =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) data->max_indirect_range >> BEFS_SB(sb)->block_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) off_t dbl_indir_off = blockno - indir_start_blk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) /* number of data blocks mapped by each of the iaddrs in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * the indirect block pointed to by the double indirect block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) size_t iblklen = BEFS_DBLINDIR_BRUN_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) /* number of data blocks mapped by each of the iaddrs in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * the double indirect block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) size_t diblklen = iblklen * befs_iaddrs_per_block(sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * BEFS_DBLINDIR_BRUN_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) befs_debug(sb, "---> %s find %lu", __func__, (unsigned long)blockno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) /* First, discover which of the double_indir->indir blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) * contains pos. Then figure out how much of pos that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * accounted for. Then discover which of the iaddrs in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) * the indirect block contains pos.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) dblindir_indx = dbl_indir_off / diblklen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) dblindir_leftover = dbl_indir_off % diblklen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) indir_indx = dblindir_leftover / diblklen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) /* Read double indirect block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) dbl_which_block = dblindir_indx / befs_iaddrs_per_block(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) if (dbl_which_block > data->double_indirect.len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) befs_error(sb, "The double-indirect index calculated by "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) "%s, %d, is outside the range "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) "of the double-indirect block", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) dblindir_indx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) dbl_indir_block =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) sb_bread(sb, iaddr2blockno(sb, &data->double_indirect) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) dbl_which_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) if (dbl_indir_block == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) befs_error(sb, "%s couldn't read the "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) "double-indirect block at blockno %lu", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) (unsigned long)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) iaddr2blockno(sb, &data->double_indirect) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) dbl_which_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) dbl_block_indx =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) dblindir_indx - (dbl_which_block * befs_iaddrs_per_block(sb));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) iaddr_array = (befs_disk_inode_addr *) dbl_indir_block->b_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) indir_run = fsrun_to_cpu(sb, iaddr_array[dbl_block_indx]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) brelse(dbl_indir_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) /* Read indirect block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) which_block = indir_indx / befs_iaddrs_per_block(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) if (which_block > indir_run.len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) befs_error(sb, "The indirect index calculated by "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) "%s, %d, is outside the range "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) "of the indirect block", __func__, indir_indx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) indir_block =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) sb_bread(sb, iaddr2blockno(sb, &indir_run) + which_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) if (indir_block == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) befs_error(sb, "%s couldn't read the indirect block "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) "at blockno %lu", __func__, (unsigned long)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) iaddr2blockno(sb, &indir_run) + which_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) return BEFS_ERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) block_indx = indir_indx - (which_block * befs_iaddrs_per_block(sb));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) iaddr_array = (befs_disk_inode_addr *) indir_block->b_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) *run = fsrun_to_cpu(sb, iaddr_array[block_indx]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) brelse(indir_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) blockno_at_run_start = indir_start_blk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) blockno_at_run_start += diblklen * dblindir_indx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) blockno_at_run_start += iblklen * indir_indx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) offset = blockno - blockno_at_run_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) run->start += offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) run->len -= offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) befs_debug(sb, "Found file block %lu in double_indirect[%d][%d],"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) " double_indirect_leftover = %lu", (unsigned long)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) blockno, dblindir_indx, indir_indx, dblindir_leftover);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) return BEFS_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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