351 lines
9.7 KiB
C
351 lines
9.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
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*/
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#include <linux/blkdev.h>
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#include <linux/slab.h>
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#include <linux/buffer_head.h>
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#include "exfat_raw.h"
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#include "exfat_fs.h"
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static const unsigned char free_bit[] = {
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/* 0 ~ 19*/
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0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3,/* 20 ~ 39*/
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0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/* 40 ~ 59*/
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0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/* 60 ~ 79*/
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2,/* 80 ~ 99*/
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0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3,/*100 ~ 119*/
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0, 1, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*120 ~ 139*/
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0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5,/*140 ~ 159*/
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*160 ~ 179*/
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0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3,/*180 ~ 199*/
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0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*200 ~ 219*/
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0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/*220 ~ 239*/
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0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 /*240 ~ 254*/
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};
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static const unsigned char used_bit[] = {
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0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3,/* 0 ~ 19*/
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2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4,/* 20 ~ 39*/
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2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,/* 40 ~ 59*/
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4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,/* 60 ~ 79*/
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2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4,/* 80 ~ 99*/
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3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,/*100 ~ 119*/
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4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4,/*120 ~ 139*/
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3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,/*140 ~ 159*/
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2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5,/*160 ~ 179*/
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4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5,/*180 ~ 199*/
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3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6,/*200 ~ 219*/
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5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,/*220 ~ 239*/
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4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 /*240 ~ 255*/
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};
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/*
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* Allocation Bitmap Management Functions
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*/
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static int exfat_allocate_bitmap(struct super_block *sb,
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struct exfat_dentry *ep)
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{
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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long long map_size;
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unsigned int i, need_map_size;
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sector_t sector;
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sbi->map_clu = le32_to_cpu(ep->dentry.bitmap.start_clu);
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map_size = le64_to_cpu(ep->dentry.bitmap.size);
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need_map_size = ((EXFAT_DATA_CLUSTER_COUNT(sbi) - 1) / BITS_PER_BYTE)
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+ 1;
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if (need_map_size != map_size) {
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exfat_err(sb, "bogus allocation bitmap size(need : %u, cur : %lld)",
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need_map_size, map_size);
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/*
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* Only allowed when bogus allocation
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* bitmap size is large
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*/
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if (need_map_size > map_size)
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return -EIO;
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}
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sbi->map_sectors = ((need_map_size - 1) >>
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(sb->s_blocksize_bits)) + 1;
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sbi->vol_amap = kvmalloc_array(sbi->map_sectors,
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sizeof(struct buffer_head *), GFP_KERNEL);
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if (!sbi->vol_amap)
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return -ENOMEM;
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sector = exfat_cluster_to_sector(sbi, sbi->map_clu);
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for (i = 0; i < sbi->map_sectors; i++) {
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sbi->vol_amap[i] = sb_bread(sb, sector + i);
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if (!sbi->vol_amap[i]) {
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/* release all buffers and free vol_amap */
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int j = 0;
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while (j < i)
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brelse(sbi->vol_amap[j++]);
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kvfree(sbi->vol_amap);
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sbi->vol_amap = NULL;
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return -EIO;
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}
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}
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return 0;
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}
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int exfat_load_bitmap(struct super_block *sb)
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{
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unsigned int i, type;
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struct exfat_chain clu;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
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while (clu.dir != EXFAT_EOF_CLUSTER) {
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for (i = 0; i < sbi->dentries_per_clu; i++) {
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struct exfat_dentry *ep;
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struct buffer_head *bh;
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ep = exfat_get_dentry(sb, &clu, i, &bh);
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if (!ep)
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return -EIO;
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type = exfat_get_entry_type(ep);
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if (type == TYPE_UNUSED)
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break;
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if (type != TYPE_BITMAP)
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continue;
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if (ep->dentry.bitmap.flags == 0x0) {
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int err;
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err = exfat_allocate_bitmap(sb, ep);
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brelse(bh);
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return err;
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}
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brelse(bh);
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}
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if (exfat_get_next_cluster(sb, &clu.dir))
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return -EIO;
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}
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return -EINVAL;
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}
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void exfat_free_bitmap(struct exfat_sb_info *sbi)
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{
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int i;
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for (i = 0; i < sbi->map_sectors; i++)
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__brelse(sbi->vol_amap[i]);
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kvfree(sbi->vol_amap);
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}
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int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync)
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{
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int i, b;
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unsigned int ent_idx;
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struct super_block *sb = inode->i_sb;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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if (!is_valid_cluster(sbi, clu))
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return -EINVAL;
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ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
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i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
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b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
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set_bit_le(b, sbi->vol_amap[i]->b_data);
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exfat_update_bh(sbi->vol_amap[i], sync);
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return 0;
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}
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void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
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{
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int i, b;
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unsigned int ent_idx;
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struct super_block *sb = inode->i_sb;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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struct exfat_mount_options *opts = &sbi->options;
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if (!is_valid_cluster(sbi, clu))
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return;
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ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
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i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
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b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
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clear_bit_le(b, sbi->vol_amap[i]->b_data);
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exfat_update_bh(sbi->vol_amap[i], sync);
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if (opts->discard) {
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int ret_discard;
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ret_discard = sb_issue_discard(sb,
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exfat_cluster_to_sector(sbi, clu),
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(1 << sbi->sect_per_clus_bits), GFP_NOFS, 0);
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if (ret_discard == -EOPNOTSUPP) {
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exfat_err(sb, "discard not supported by device, disabling");
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opts->discard = 0;
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}
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}
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}
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/*
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* If the value of "clu" is 0, it means cluster 2 which is the first cluster of
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* the cluster heap.
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*/
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unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu)
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{
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unsigned int i, map_i, map_b, ent_idx;
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unsigned int clu_base, clu_free;
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unsigned char k, clu_mask;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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WARN_ON(clu < EXFAT_FIRST_CLUSTER);
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ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
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clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx & ~(BITS_PER_BYTE_MASK));
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clu_mask = IGNORED_BITS_REMAINED(clu, clu_base);
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map_i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
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map_b = BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent_idx);
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for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters;
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i += BITS_PER_BYTE) {
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k = *(sbi->vol_amap[map_i]->b_data + map_b);
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if (clu_mask > 0) {
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k |= clu_mask;
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clu_mask = 0;
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}
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if (k < 0xFF) {
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clu_free = clu_base + free_bit[k];
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if (clu_free < sbi->num_clusters)
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return clu_free;
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}
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clu_base += BITS_PER_BYTE;
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if (++map_b >= sb->s_blocksize ||
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clu_base >= sbi->num_clusters) {
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if (++map_i >= sbi->map_sectors) {
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clu_base = EXFAT_FIRST_CLUSTER;
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map_i = 0;
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}
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map_b = 0;
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}
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}
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return EXFAT_EOF_CLUSTER;
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}
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int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count)
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{
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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unsigned int count = 0;
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unsigned int i, map_i = 0, map_b = 0;
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unsigned int total_clus = EXFAT_DATA_CLUSTER_COUNT(sbi);
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unsigned int last_mask = total_clus & BITS_PER_BYTE_MASK;
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unsigned char clu_bits;
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const unsigned char last_bit_mask[] = {0, 0b00000001, 0b00000011,
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0b00000111, 0b00001111, 0b00011111, 0b00111111, 0b01111111};
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total_clus &= ~last_mask;
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for (i = 0; i < total_clus; i += BITS_PER_BYTE) {
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clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
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count += used_bit[clu_bits];
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if (++map_b >= (unsigned int)sb->s_blocksize) {
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map_i++;
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map_b = 0;
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}
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}
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if (last_mask) {
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clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
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clu_bits &= last_bit_mask[last_mask];
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count += used_bit[clu_bits];
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}
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*ret_count = count;
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return 0;
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}
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int exfat_trim_fs(struct inode *inode, struct fstrim_range *range)
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{
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unsigned int trim_begin, trim_end, count, next_free_clu;
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u64 clu_start, clu_end, trim_minlen, trimmed_total = 0;
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struct super_block *sb = inode->i_sb;
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struct exfat_sb_info *sbi = EXFAT_SB(sb);
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int err = 0;
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clu_start = max_t(u64, range->start >> sbi->cluster_size_bits,
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EXFAT_FIRST_CLUSTER);
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clu_end = clu_start + (range->len >> sbi->cluster_size_bits) - 1;
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trim_minlen = range->minlen >> sbi->cluster_size_bits;
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if (clu_start >= sbi->num_clusters || range->len < sbi->cluster_size)
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return -EINVAL;
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if (clu_end >= sbi->num_clusters)
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clu_end = sbi->num_clusters - 1;
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mutex_lock(&sbi->bitmap_lock);
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trim_begin = trim_end = exfat_find_free_bitmap(sb, clu_start);
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if (trim_begin == EXFAT_EOF_CLUSTER)
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goto unlock;
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next_free_clu = exfat_find_free_bitmap(sb, trim_end + 1);
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if (next_free_clu == EXFAT_EOF_CLUSTER)
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goto unlock;
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do {
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if (next_free_clu == trim_end + 1) {
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/* extend trim range for continuous free cluster */
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trim_end++;
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} else {
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/* trim current range if it's larger than trim_minlen */
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count = trim_end - trim_begin + 1;
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if (count >= trim_minlen) {
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err = sb_issue_discard(sb,
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exfat_cluster_to_sector(sbi, trim_begin),
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count * sbi->sect_per_clus, GFP_NOFS, 0);
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if (err)
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goto unlock;
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trimmed_total += count;
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}
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/* set next start point of the free hole */
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trim_begin = trim_end = next_free_clu;
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}
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if (next_free_clu >= clu_end)
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break;
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if (fatal_signal_pending(current)) {
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err = -ERESTARTSYS;
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goto unlock;
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}
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next_free_clu = exfat_find_free_bitmap(sb, next_free_clu + 1);
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} while (next_free_clu != EXFAT_EOF_CLUSTER &&
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next_free_clu > trim_end);
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/* try to trim remainder */
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count = trim_end - trim_begin + 1;
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if (count >= trim_minlen) {
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err = sb_issue_discard(sb, exfat_cluster_to_sector(sbi, trim_begin),
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count * sbi->sect_per_clus, GFP_NOFS, 0);
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if (err)
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goto unlock;
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trimmed_total += count;
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}
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unlock:
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mutex_unlock(&sbi->bitmap_lock);
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range->len = trimmed_total << sbi->cluster_size_bits;
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return err;
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}
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